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The SUBSLICE_MASK GETPARAM interface isn't a well defined api #5

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rib opened this issue Jan 19, 2016 · 1 comment
Open

The SUBSLICE_MASK GETPARAM interface isn't a well defined api #5

rib opened this issue Jan 19, 2016 · 1 comment

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@rib
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rib commented Jan 19, 2016

Packing sub slice masks for all slices into a single mask is possible for current Gens but from userspace it's awkward to work with if it's not sure how many bits are used for each sub slice mask.

Although we expect for Broadwell the maximum number of slices to be 2, the HW has EU disable registers that theoretically account for up to 3 slices and the implementation of broadwell_sseu_info_init() works in terms of 3 as the maximum number of slices.

This isn't obvious to userspace which might reasonably assume only 2 bits are used for each sub slice mask on Broadwell. An interface that can avoid this kind of ambiguity would be less error prone.

@matt-auld
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So If I understand this correctly, on gen graphics the hardware is split up into so called 'slices', the number of which is specific to each gen. Each slice is then made up of some number 'sub-slices', again specific to each gen, a sub-slice then has some number of EU's, usually 8(always?) , so on gen9 we have 3 slices, and 3 sub-slices, giving us 72 EU's. I guess the slicing idea is mostly helpful for power management, since slices/sub-slices can be power gated?

But this seems to be complicated by the fact that some number of, slices/sub-slices/EU's can be disabled, as seen in the various sseu_info_init methods. Why would these units ever need to be disabled?

Anyway, so the whole point of this is for the OA work, where there is this mythical $SubsliceMask in the xml files, which I guess is used in the equations to derive the various counter values, and this value is itself derived from the subslice_mask. Specifically this seems to be a u32 mask, which is the ss_disable mask covering all enabled slices, as a single mask. So for CHV, which has only 1 slice and 2 sub-slices, this becomes nice and simple.

Why is it that this 'packing' process happens again in GPU top, which seems kind of funky, but I'm probably missing something.

Also as a side-note in GPU top the gen9 ss_max is hard-coded to 4, but in the kernel the value is 3, and for gen8 s_max is 2 but the in the kernel 3.

rib pushed a commit that referenced this issue Feb 22, 2016
Fixes segmentation fault using, for instance:

  (gdb) run record -I -e intel_pt/tsc=1,noretcomp=1/u /bin/ls
  Starting program: /home/acme/bin/perf record -I -e intel_pt/tsc=1,noretcomp=1/u /bin/ls
  Missing separate debuginfos, use: dnf debuginfo-install glibc-2.22-7.fc23.x86_64
  [Thread debugging using libthread_db enabled]
  Using host libthread_db library "/lib64/libthread_db.so.1".

 Program received signal SIGSEGV, Segmentation fault.
  0 x00000000004b9ea5 in tracepoint_error (e=0x0, err=13, sys=0x19b1370 "sched", name=0x19a5d00 "sched_switch") at util/parse-events.c:410
  (gdb) bt
  #0  0x00000000004b9ea5 in tracepoint_error (e=0x0, err=13, sys=0x19b1370 "sched", name=0x19a5d00 "sched_switch") at util/parse-events.c:410
  #1  0x00000000004b9fc5 in add_tracepoint (list=0x19a5d20, idx=0x7fffffffb8c0, sys_name=0x19b1370 "sched", evt_name=0x19a5d00 "sched_switch", err=0x0, head_config=0x0)
      at util/parse-events.c:433
  #2  0x00000000004ba334 in add_tracepoint_event (list=0x19a5d20, idx=0x7fffffffb8c0, sys_name=0x19b1370 "sched", evt_name=0x19a5d00 "sched_switch", err=0x0, head_config=0x0)
      at util/parse-events.c:498
  #3  0x00000000004bb699 in parse_events_add_tracepoint (list=0x19a5d20, idx=0x7fffffffb8c0, sys=0x19b1370 "sched", event=0x19a5d00 "sched_switch", err=0x0, head_config=0x0)
      at util/parse-events.c:936
  #4  0x00000000004f6eda in parse_events_parse (_data=0x7fffffffb8b0, scanner=0x19a49d0) at util/parse-events.y:391
  #5  0x00000000004bc8e5 in parse_events__scanner (str=0x663ff2 "sched:sched_switch", data=0x7fffffffb8b0, start_token=258) at util/parse-events.c:1361
  #6  0x00000000004bca57 in parse_events (evlist=0x19a5220, str=0x663ff2 "sched:sched_switch", err=0x0) at util/parse-events.c:1401
  #7  0x0000000000518d5f in perf_evlist__can_select_event (evlist=0x19a3b90, str=0x663ff2 "sched:sched_switch") at util/record.c:253
  #8  0x0000000000553c42 in intel_pt_track_switches (evlist=0x19a3b90) at arch/x86/util/intel-pt.c:364
  #9  0x00000000005549d1 in intel_pt_recording_options (itr=0x19a2c40, evlist=0x19a3b90, opts=0x8edf68 <record+232>) at arch/x86/util/intel-pt.c:664
  #10 0x000000000051e076 in auxtrace_record__options (itr=0x19a2c40, evlist=0x19a3b90, opts=0x8edf68 <record+232>) at util/auxtrace.c:539
  #11 0x0000000000433368 in cmd_record (argc=1, argv=0x7fffffffde60, prefix=0x0) at builtin-record.c:1264
  #12 0x000000000049bec2 in run_builtin (p=0x8fa2a8 <commands+168>, argc=5, argv=0x7fffffffde60) at perf.c:390
  #13 0x000000000049c12a in handle_internal_command (argc=5, argv=0x7fffffffde60) at perf.c:451
  #14 0x000000000049c278 in run_argv (argcp=0x7fffffffdcbc, argv=0x7fffffffdcb0) at perf.c:495
  #15 0x000000000049c60a in main (argc=5, argv=0x7fffffffde60) at perf.c:618
(gdb)

Intel PT attempts to find the sched:sched_switch tracepoint but that seg
faults if tracefs is not readable, because the error reporting structure
is null, as errors are not reported when automatically adding
tracepoints.  Fix by checking before using.

Committer note:

This doesn't take place in a kernel that supports
perf_event_attr.context_switch, that is the default way that will be
used for tracking context switches, only in older kernels, like 4.2, in
a machine with Intel PT (e.g. Broadwell) for non-priviledged users.

Further info from a similar patch by Wang:

The error is in tracepoint_error: it assumes the 'e' parameter is valid.

However, there are many situation a parse_event() can be called without
parse_events_error. See result of

  $ grep 'parse_events(.*NULL)' ./tools/perf/ -r'

Signed-off-by: Adrian Hunter <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Tong Zhang <[email protected]>
Cc: Wang Nan <[email protected]>
Cc: [email protected] # v4.4+
Fixes: 1965817 ("perf tools: Enhance parsing events tracepoint error output")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Mar 15, 2016
If we use USB ID pin as wakeup source, and there is a USB block
device on this USB OTG (ID) cable, the system will be deadlock
after system resume.

The root cause for this problem is: the workqueue ci_otg may try
to remove hcd before the driver resume has finished, and hcd will
disconnect the device on it, then, it will call device_release_driver,
and holds the device lock "dev->mutex", but it is never unlocked since
it waits workqueue writeback to run to flush the block information, but
the workqueue writeback is freezable, it is not thawed before driver
resume has finished.

When the driver (device: sd 0:0:0:0:) resume goes to dpm_complete, it
tries to get its device lock "dev->mutex", but it can't get it forever,
then the deadlock occurs. Below call stacks show the situation.

So, in order to fix this problem, we need to change workqueue ci_otg
as freezable, then the work item in this workqueue will be run after
driver's resume, this workqueue will not be blocked forever like above
case since the workqueue writeback has been thawed too.

Tested at: i.mx6qdl-sabresd and i.mx6sx-sdb.

[  555.178869] kworker/u2:13   D c07de74c     0   826      2 0x00000000
[  555.185310] Workqueue: ci_otg ci_otg_work
[  555.189353] Backtrace:
[  555.191849] [<c07de4fc>] (__schedule) from [<c07dec6c>] (schedule+0x48/0xa0)
[  555.198912]  r10:ee471ba0 r9:00000000 r8:00000000 r7:00000002 r6:ee470000 r5:ee471ba4
[  555.206867]  r4:ee470000
[  555.209453] [<c07dec24>] (schedule) from [<c07e2fc4>] (schedule_timeout+0x15c/0x1e0)
[  555.217212]  r4:7fffffff r3:edc2b000
[  555.220862] [<c07e2e68>] (schedule_timeout) from [<c07df6c8>] (wait_for_common+0x94/0x144)
[  555.229140]  r8:00000000 r7:00000002 r6:ee470000 r5:ee471ba4 r4:7fffffff
[  555.235980] [<c07df634>] (wait_for_common) from [<c07df790>] (wait_for_completion+0x18/0x1c)
[  555.244430]  r10:00000001 r9:c0b5563c r8:c0042e48 r7:ef086000 r6:eea4372c r5:ef131b00
[  555.252383]  r4:00000000
[  555.254970] [<c07df778>] (wait_for_completion) from [<c0043cb8>] (flush_work+0x19c/0x234)
[  555.263177] [<c0043b1c>] (flush_work) from [<c0043fac>] (flush_delayed_work+0x48/0x4c)
[  555.271106]  r8:ed5b5000 r7:c0b38a3c r6:eea439cc r5:eea4372c r4:eea4372c
[  555.277958] [<c0043f64>] (flush_delayed_work) from [<c00eae18>] (bdi_unregister+0x84/0xec)
[  555.286236]  r4:eea43520 r3:20000153
[  555.289885] [<c00ead94>] (bdi_unregister) from [<c02c2154>] (blk_cleanup_queue+0x180/0x29c)
[  555.298250]  r5:eea43808 r4:eea43400
[  555.301909] [<c02c1fd4>] (blk_cleanup_queue) from [<c0417914>] (__scsi_remove_device+0x48/0xb8)
[  555.310623]  r7:00000000 r6:20000153 r5:ededa950 r4:ededa800
[  555.316403] [<c04178cc>] (__scsi_remove_device) from [<c0415e90>] (scsi_forget_host+0x64/0x68)
[  555.325028]  r5:ededa800 r4:ed5b5000
[  555.328689] [<c0415e2c>] (scsi_forget_host) from [<c0409828>] (scsi_remove_host+0x78/0x104)
[  555.337054]  r5:ed5b5068 r4:ed5b5000
[  555.340709] [<c04097b0>] (scsi_remove_host) from [<c04cdfcc>] (usb_stor_disconnect+0x50/0xb4)
[  555.349247]  r6:ed5b56e4 r5:ed5b5818 r4:ed5b5690 r3:00000008
[  555.355025] [<c04cdf7c>] (usb_stor_disconnect) from [<c04b3bc8>] (usb_unbind_interface+0x78/0x25c)
[  555.363997]  r8:c13919b4 r7:edd3c000 r6:edd3c020 r5:ee551c68 r4:ee551c00 r3:c04cdf7c
[  555.371892] [<c04b3b50>] (usb_unbind_interface) from [<c03dc248>] (__device_release_driver+0x8c/0x118)
[  555.381213]  r10:00000001 r9:edd90c00 r8:c13919b4 r7:ee551c68 r6:c0b546e0 r5:c0b5563c
[  555.389167]  r4:edd3c020
[  555.391752] [<c03dc1bc>] (__device_release_driver) from [<c03dc2fc>] (device_release_driver+0x28/0x34)
[  555.401071]  r5:edd3c020 r4:edd3c054
[  555.404721] [<c03dc2d4>] (device_release_driver) from [<c03db304>] (bus_remove_device+0xe0/0x110)
[  555.413607]  r5:edd3c020 r4:ef17f04c
[  555.417253] [<c03db224>] (bus_remove_device) from [<c03d8128>] (device_del+0x114/0x21c)
[  555.425270]  r6:edd3c028 r5:edd3c020 r4:ee551c00 r3:00000000
[  555.431045] [<c03d8014>] (device_del) from [<c04b1560>] (usb_disable_device+0xa4/0x1e8)
[  555.439061]  r8:edd3c000 r7:eded8000 r6:00000000 r5:00000001 r4:ee551c00
[  555.445906] [<c04b14bc>] (usb_disable_device) from [<c04a8e54>] (usb_disconnect+0x74/0x224)
[  555.454271]  r9:edd90c00 r8:ee551000 r7:ee551c68 r6:ee551c9c r5:ee551c00 r4:00000001
[  555.462156] [<c04a8de0>] (usb_disconnect) from [<c04a8fb8>] (usb_disconnect+0x1d8/0x224)
[  555.470259]  r10:00000001 r9:edd90000 r8:ee471e2c r7:ee551468 r6:ee55149c r5:ee551400
[  555.478213]  r4:00000001
[  555.480797] [<c04a8de0>] (usb_disconnect) from [<c04ae5ec>] (usb_remove_hcd+0xa0/0x1ac)
[  555.488813]  r10:00000001 r9:ee471eb0 r8:00000000 r7:ef3d9500 r6:eded810c r5:eded80b0
[  555.496765]  r4:eded8000
[  555.499351] [<c04ae54c>] (usb_remove_hcd) from [<c04d4158>] (host_stop+0x28/0x64)
[  555.506847]  r6:eeb50010 r5:eded8000 r4:eeb51010
[  555.511563] [<c04d4130>] (host_stop) from [<c04d09b8>] (ci_otg_work+0xc4/0x124)
[  555.518885]  r6:00000001 r5:eeb50010 r4:eeb502a0 r3:c04d4130
[  555.524665] [<c04d08f4>] (ci_otg_work) from [<c00454f0>] (process_one_work+0x194/0x420)
[  555.532682]  r6:ef086000 r5:eeb502a0 r4:edc44480
[  555.537393] [<c004535c>] (process_one_work) from [<c00457b0>] (worker_thread+0x34/0x514)
[  555.545496]  r10:edc44480 r9:ef086000 r8:c0b1a100 r7:ef086034 r6:00000088 r5:edc44498
[  555.553450]  r4:ef086000
[  555.556032] [<c004577c>] (worker_thread) from [<c004bab4>] (kthread+0xdc/0xf8)
[  555.563268]  r10:00000000 r9:00000000 r8:00000000 r7:c004577c r6:edc44480 r5:eddc15c0
[  555.571221]  r4:00000000
[  555.573804] [<c004b9d8>] (kthread) from [<c000fef0>] (ret_from_fork+0x14/0x24)
[  555.581040]  r7:00000000 r6:00000000 r5:c004b9d8 r4:eddc15c0

[  553.429383] sh              D c07de74c     0   694    691 0x00000000
[  553.435801] Backtrace:
[  553.438295] [<c07de4fc>] (__schedule) from [<c07dec6c>] (schedule+0x48/0xa0)
[  553.445358]  r10:edd3c054 r9:edd3c078 r8:edddbd50 r7:edcbbc00 r6:c1377c34 r5:60000153
[  553.453313]  r4:eddda000
[  553.455896] [<c07dec24>] (schedule) from [<c07deff8>] (schedule_preempt_disabled+0x10/0x14)
[  553.464261]  r4:edd3c058 r3:0000000a
[  553.467910] [<c07defe8>] (schedule_preempt_disabled) from [<c07e0bbc>] (mutex_lock_nested+0x1a0/0x3e8)
[  553.477254] [<c07e0a1c>] (mutex_lock_nested) from [<c03e927c>] (dpm_complete+0xc0/0x1b0)
[  553.485358]  r10:00561408 r9:edd3c054 r8:c0b4863c r7:edddbd90 r6:c0b485d8 r5:edd3c020
[  553.493313]  r4:edd3c0d0
[  553.495896] [<c03e91bc>] (dpm_complete) from [<c03e9388>] (dpm_resume_end+0x1c/0x20)
[  553.503652]  r9:00000000 r8:c0b1a9d0 r7:c1334ec0 r6:c1334edc r5:00000003 r4:00000010
[  553.511544] [<c03e936c>] (dpm_resume_end) from [<c0079894>] (suspend_devices_and_enter+0x158/0x504)
[  553.520604]  r4:00000000 r3:c1334efc
[  553.524250] [<c007973c>] (suspend_devices_and_enter) from [<c0079e74>] (pm_suspend+0x234/0x2cc)
[  553.532961]  r10:00561408 r9:ed6b7300 r8:00000004 r7:c1334eec r6:00000000 r5:c1334ee8
[  553.540914]  r4:00000003
[  553.543493] [<c0079c40>] (pm_suspend) from [<c0078a6c>] (state_store+0x6c/0xc0)

[  555.703684] 7 locks held by kworker/u2:13/826:
[  555.708140]  #0:  ("%s""ci_otg"){++++.+}, at: [<c0045484>] process_one_work+0x128/0x420
[  555.716277]  rib#1:  ((&ci->work)){+.+.+.}, at: [<c0045484>] process_one_work+0x128/0x420
[  555.724317]  rib#2:  (usb_bus_list_lock){+.+.+.}, at: [<c04ae5e4>] usb_remove_hcd+0x98/0x1ac
[  555.732626]  rib#3:  (&dev->mutex){......}, at: [<c04a8e28>] usb_disconnect+0x48/0x224
[  555.740403]  rib#4:  (&dev->mutex){......}, at: [<c04a8e28>] usb_disconnect+0x48/0x224
[  555.748179]  rib#5:  (&dev->mutex){......}, at: [<c03dc2f4>] device_release_driver+0x20/0x34
[  555.756487]  rib#6:  (&shost->scan_mutex){+.+.+.}, at: [<c04097d0>] scsi_remove_host+0x20/0x104

Cc: <[email protected]> #v3.14+
Cc: Jun Li <[email protected]>
Signed-off-by: Peter Chen <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Jul 18, 2016
The incorrect GPIO mask cause kernel warning, when AR9462 access GPIO11.
Also fix the mask for AR9565.

WARNING: CPU: 1 PID: 199 at ../drivers/net/wireless/ath/ath9k/hw.c:2778 ath9k_hw_gpio_get+0x1a9/0x1b0 [ath9k_hw]
CPU: 1 PID: 199 Comm: kworker/u16:9 Not tainted 4.7.0-rc1-next-20160530+ rib#5
Hardware name: Acer TravelMate P243/BA40_HC, BIOS V1.01 04/20/2012
Workqueue: events_power_efficient rfkill_poll
 0000000000000000 ffff88002cf73d28 ffffffff813b8ddc 0000000000000000
 0000000000000000 ffff88002cf73d68 ffffffff8107a331 00000ada00000086
 ffff880148d9c018 000000000000000b ffff880147e68720 0000000000000200
Call Trace:
 [<ffffffff813b8ddc>] dump_stack+0x63/0x87
 [<ffffffff8107a331>] __warn+0xd1/0xf0
 [<ffffffff8107a41d>] warn_slowpath_null+0x1d/0x20
 [<ffffffffc0775b19>] ath9k_hw_gpio_get+0x1a9/0x1b0 [ath9k_hw]
 [<ffffffffc047f3e4>] ath9k_rfkill_poll_state+0x34/0x60 [ath9k]
 [<ffffffffc06dbb53>] ieee80211_rfkill_poll+0x33/0x40 [mac80211]
 [<ffffffffc03ad65a>] cfg80211_rfkill_poll+0x2a/0xc0 [cfg80211]
 [<ffffffff817c5514>] rfkill_poll+0x24/0x50
 [<ffffffff81093183>] process_one_work+0x153/0x3f0
 [<ffffffff8109393b>] worker_thread+0x12b/0x4b0
 [<ffffffff81093810>] ? rescuer_thread+0x340/0x340
 [<ffffffff81099129>] kthread+0xc9/0xe0
 [<ffffffff817d8f1f>] ret_from_fork+0x1f/0x40
 [<ffffffff81099060>] ? kthread_park+0x60/0x60

Fixes: a01ab81 ("ath9k: define correct GPIO numbers and bits mask")
Reported-by: Sudip Mukherjee <[email protected]>
Tested-by: Sudip Mukherjee <[email protected]>
Signed-off-by: Miaoqing Pan <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Sep 16, 2016
If kexec_apply_relocations fails, kexec_load_purgatory frees pi->sechdrs
and pi->purgatory_buf.  This is redundant, because in case of error
kimage_file_prepare_segments calls kimage_file_post_load_cleanup, which
will also free those buffers.

This causes two warnings like the following, one for pi->sechdrs and the
other for pi->purgatory_buf:

  kexec-bzImage64: Loading purgatory failed
  ------------[ cut here ]------------
  WARNING: CPU: 1 PID: 2119 at mm/vmalloc.c:1490 __vunmap+0xc1/0xd0
  Trying to vfree() nonexistent vm area (ffffc90000e91000)
  Modules linked in:
  CPU: 1 PID: 2119 Comm: kexec Not tainted 4.8.0-rc3+ rib#5
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  Call Trace:
    dump_stack+0x4d/0x65
    __warn+0xcb/0xf0
    warn_slowpath_fmt+0x4f/0x60
    ? find_vmap_area+0x19/0x70
    ? kimage_file_post_load_cleanup+0x47/0xb0
    __vunmap+0xc1/0xd0
    vfree+0x2e/0x70
    kimage_file_post_load_cleanup+0x5e/0xb0
    SyS_kexec_file_load+0x448/0x680
    ? putname+0x54/0x60
    ? do_sys_open+0x190/0x1f0
    entry_SYSCALL_64_fastpath+0x13/0x8f
  ---[ end trace 158bb74f5950ca2b ]---

Fix by setting pi->sechdrs an pi->purgatory_buf to NULL, since vfree
won't try to free a NULL pointer.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thiago Jung Bauermann <[email protected]>
Acked-by: Baoquan He <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Vivek Goyal <[email protected]>
Cc: Dave Young <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Sep 19, 2016
For pure station mode, iter_data.primary_beacon_vif was used and passed
to ath_beacon_config, but not set to the station vif.
This was causing the following warning:

[  100.310919] ------------[ cut here ]------------
[  100.315683] WARNING: CPU: 0 PID: 7 at compat-wireless-2016-06-20/drivers/net/wireless/ath/ath9k/beacon.c:642 ath9k_calculate_summary_state+0x250/0x60c [ath9k]()
[  100.402028] CPU: 0 PID: 7 Comm: kworker/u2:1 Tainted: G        W       4.4.15 rib#5
[  100.409676] Workqueue: phy0 ieee80211_ibss_leave [mac80211]
[  100.415351] Stack : 8736e98c 870b4b20 87a25b54 800a6800 8782a080 80400d63 8039b96c 00000007
[  100.415351]    803c5edc 87875914 80400000 800a47cc 87a25b54 800a6800 803a0fd8 80400000
[  100.415351]    00000003 87875914 80400000 80094ae0 87a25b54 8787594c 00000000 801ef308
[  100.415351]    803ffe70 801ef300 87193d58 87b3a400 87b3ad00 70687930 00000000 00000000
[  100.415351]    00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[  100.415351]    ...
[  100.451703] Call Trace:
[  100.454235] [<800a6800>] vprintk_default+0x24/0x30
[  100.459110] [<800a47cc>] printk+0x2c/0x38
[  100.463190] [<800a6800>] vprintk_default+0x24/0x30
[  100.468072] [<80094ae0>] print_worker_info+0x148/0x174
[  100.473378] [<801ef308>] serial8250_console_putchar+0x0/0x44
[  100.479122] [<801ef300>] wait_for_xmitr+0xc4/0xcc
[  100.484014] [<87193d58>] ieee80211_ibss_leave+0xb90/0x1900 [mac80211]
[  100.490590] [<80081604>] warn_slowpath_common+0xa0/0xd0
[  100.495922] [<801a359c>] dump_stack+0x14/0x28
[  100.500350] [<80071a00>] show_stack+0x50/0x84
[  100.504784] [<80081604>] warn_slowpath_common+0xa0/0xd0
[  100.510106] [<87024c60>] ath9k_calculate_summary_state+0x250/0x60c [ath9k]
[  100.517105] [<800816b8>] warn_slowpath_null+0x18/0x24
[  100.522256] [<87024c60>] ath9k_calculate_summary_state+0x250/0x60c [ath9k]
[  100.529273] [<87025418>] ath9k_set_txpower+0x148/0x498 [ath9k]
[  100.535302] [<871d2c64>] cleanup_module+0xa74/0xd4c [mac80211]
[  100.541237] [<801ef308>] serial8250_console_putchar+0x0/0x44
[  100.547042] [<800a5d18>] wake_up_klogd+0x54/0x68
[  100.551730] [<800a6650>] vprintk_emit+0x404/0x43c
[  100.556623] [<871b9db8>] ieee80211_sta_rx_notify+0x258/0x32c [mac80211]
[  100.563475] [<871ba6a4>] ieee80211_sta_rx_queued_mgmt+0x63c/0x734 [mac80211]
[  100.570693] [<871aa49c>] ieee80211_tx_prepare_skb+0x210/0x230 [mac80211]
[  100.577609] [<800af5d4>] mod_timer+0x15c/0x190
[  100.582220] [<871ba8b8>] ieee80211_sta_work+0xfc/0xe1c [mac80211]
[  100.588539] [<871940b4>] ieee80211_ibss_leave+0xeec/0x1900 [mac80211]
[  100.595122] [<8009ec84>] dequeue_task_fair+0x44/0x130
[  100.600281] [<80092a34>] process_one_work+0x1f8/0x334
[  100.605454] [<80093830>] worker_thread+0x2b4/0x408
[  100.610317] [<8009357c>] worker_thread+0x0/0x408
[  100.615019] [<8009357c>] worker_thread+0x0/0x408
[  100.619705] [<80097b68>] kthread+0xdc/0xe8
[  100.623886] [<80097a8c>] kthread+0x0/0xe8
[  100.627961] [<80060878>] ret_from_kernel_thread+0x14/0x1c
[  100.633448]
[  100.634956] ---[ end trace aafbe57e9ae6862f ]---

Fixes: cfda2d8 ("ath9k: Fix beacon configuration for addition/removal of interfaces")
Signed-off-by: Felix Fietkau <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Dec 6, 2016
Tushar Dave says:

====================
sparc: Enable sun4v hypervisor PCI IOMMU v2 APIs and ATU

ATU (Address Translation Unit) is a new IOMMU in SPARC supported with
sun4v hypervisor PCI IOMMU v2 APIs.

Current SPARC IOMMU supports only 32bit address ranges and one TSB
per PCIe root complex that has a 2GB per root complex DVMA space
limit. The limit has become a scalability bottleneck nowadays that
a typical 10G/40G NIC can consume 500MB DVMA space per instance.
When DVMA resource is exhausted, devices will not be usable
since the driver can't allocate DVMA.

For example, we recently experienced legacy IOMMU limitation while
using i40e driver in system with large number of CPUs (e.g. 128).
Four ports of i40e, each request 128 QP (Queue Pairs). Each queue has
512 (default) descriptors. So considering only RX queues (because RX
premap DMA buffers), i40e takes 4*128*512 number of DMA entries in
IOMMU table. Legacy IOMMU can have at max (2G/8K)- 1 entries available
in table. So bringing up four instance of i40e alone saturate existing
IOMMU resource.

ATU removes bottleneck by allowing guest os to create IOTSB of size
32G (or more) with 64bit address ranges available in ATU HW. 32G is
more than enough DVMA space to be shared by all PCIe devices under
root complex contrast to 2G space provided by legacy IOMMU.

ATU allows PCIe devices to use 64bit DMA addressing. Devices
which choose to use 32bit DMA mask will continue to work with the
existing legacy IOMMU.

The patch set is tested on sun4v (T1000, T2000, T3, T4, T5, T7, S7)
and sun4u SPARC.

Thanks.
-Tushar

v2->v3:
- Patch rib#5 addresses comment by Joe Perches.
 -- use %s, __func__ instead of embedding the function name.

v1->v2:
- Patch rib#2 addresses comments by Dave M.
 -- use page allocator to allocate IOTSB.
 -- use true/false with boolean variables.
====================

Signed-off-by: David S. Miller <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Feb 21, 2017
We cannot do printk() from tk_debug_account_sleep_time(), because
tk_debug_account_sleep_time() is called under tk_core seq lock.
The reason why printk() is unsafe there is that console_sem may
invoke scheduler (up()->wake_up_process()->activate_task()), which,
in turn, can return back to timekeeping code, for instance, via
get_time()->ktime_get(), deadlocking the system on tk_core seq lock.

[   48.950592] ======================================================
[   48.950622] [ INFO: possible circular locking dependency detected ]
[   48.950622] 4.10.0-rc7-next-20170213+ torvalds#101 Not tainted
[   48.950622] -------------------------------------------------------
[   48.950622] kworker/0:0/3 is trying to acquire lock:
[   48.950653]  (tk_core){----..}, at: [<c01cc624>] retrigger_next_event+0x4c/0x90
[   48.950683]
               but task is already holding lock:
[   48.950683]  (hrtimer_bases.lock){-.-...}, at: [<c01cc610>] retrigger_next_event+0x38/0x90
[   48.950714]
               which lock already depends on the new lock.

[   48.950714]
               the existing dependency chain (in reverse order) is:
[   48.950714]
               -> rib#5 (hrtimer_bases.lock){-.-...}:
[   48.950744]        _raw_spin_lock_irqsave+0x50/0x64
[   48.950775]        lock_hrtimer_base+0x28/0x58
[   48.950775]        hrtimer_start_range_ns+0x20/0x5c8
[   48.950775]        __enqueue_rt_entity+0x320/0x360
[   48.950805]        enqueue_rt_entity+0x2c/0x44
[   48.950805]        enqueue_task_rt+0x24/0x94
[   48.950836]        ttwu_do_activate+0x54/0xc0
[   48.950836]        try_to_wake_up+0x248/0x5c8
[   48.950836]        __setup_irq+0x420/0x5f0
[   48.950836]        request_threaded_irq+0xdc/0x184
[   48.950866]        devm_request_threaded_irq+0x58/0xa4
[   48.950866]        omap_i2c_probe+0x530/0x6a0
[   48.950897]        platform_drv_probe+0x50/0xb0
[   48.950897]        driver_probe_device+0x1f8/0x2cc
[   48.950897]        __driver_attach+0xc0/0xc4
[   48.950927]        bus_for_each_dev+0x6c/0xa0
[   48.950927]        bus_add_driver+0x100/0x210
[   48.950927]        driver_register+0x78/0xf4
[   48.950958]        do_one_initcall+0x3c/0x16c
[   48.950958]        kernel_init_freeable+0x20c/0x2d8
[   48.950958]        kernel_init+0x8/0x110
[   48.950988]        ret_from_fork+0x14/0x24
[   48.950988]
               -> rib#4 (&rt_b->rt_runtime_lock){-.-...}:
[   48.951019]        _raw_spin_lock+0x40/0x50
[   48.951019]        rq_offline_rt+0x9c/0x2bc
[   48.951019]        set_rq_offline.part.2+0x2c/0x58
[   48.951049]        rq_attach_root+0x134/0x144
[   48.951049]        cpu_attach_domain+0x18c/0x6f4
[   48.951049]        build_sched_domains+0xba4/0xd80
[   48.951080]        sched_init_smp+0x68/0x10c
[   48.951080]        kernel_init_freeable+0x160/0x2d8
[   48.951080]        kernel_init+0x8/0x110
[   48.951080]        ret_from_fork+0x14/0x24
[   48.951110]
               -> rib#3 (&rq->lock){-.-.-.}:
[   48.951110]        _raw_spin_lock+0x40/0x50
[   48.951141]        task_fork_fair+0x30/0x124
[   48.951141]        sched_fork+0x194/0x2e0
[   48.951141]        copy_process.part.5+0x448/0x1a20
[   48.951171]        _do_fork+0x98/0x7e8
[   48.951171]        kernel_thread+0x2c/0x34
[   48.951171]        rest_init+0x1c/0x18c
[   48.951202]        start_kernel+0x35c/0x3d4
[   48.951202]        0x8000807c
[   48.951202]
               -> rib#2 (&p->pi_lock){-.-.-.}:
[   48.951232]        _raw_spin_lock_irqsave+0x50/0x64
[   48.951232]        try_to_wake_up+0x30/0x5c8
[   48.951232]        up+0x4c/0x60
[   48.951263]        __up_console_sem+0x2c/0x58
[   48.951263]        console_unlock+0x3b4/0x650
[   48.951263]        vprintk_emit+0x270/0x474
[   48.951293]        vprintk_default+0x20/0x28
[   48.951293]        printk+0x20/0x30
[   48.951324]        kauditd_hold_skb+0x94/0xb8
[   48.951324]        kauditd_thread+0x1a4/0x56c
[   48.951324]        kthread+0x104/0x148
[   48.951354]        ret_from_fork+0x14/0x24
[   48.951354]
               -> rib#1 ((console_sem).lock){-.....}:
[   48.951385]        _raw_spin_lock_irqsave+0x50/0x64
[   48.951385]        down_trylock+0xc/0x2c
[   48.951385]        __down_trylock_console_sem+0x24/0x80
[   48.951385]        console_trylock+0x10/0x8c
[   48.951416]        vprintk_emit+0x264/0x474
[   48.951416]        vprintk_default+0x20/0x28
[   48.951416]        printk+0x20/0x30
[   48.951446]        tk_debug_account_sleep_time+0x5c/0x70
[   48.951446]        __timekeeping_inject_sleeptime.constprop.3+0x170/0x1a0
[   48.951446]        timekeeping_resume+0x218/0x23c
[   48.951477]        syscore_resume+0x94/0x42c
[   48.951477]        suspend_enter+0x554/0x9b4
[   48.951477]        suspend_devices_and_enter+0xd8/0x4b4
[   48.951507]        enter_state+0x934/0xbd4
[   48.951507]        pm_suspend+0x14/0x70
[   48.951507]        state_store+0x68/0xc8
[   48.951538]        kernfs_fop_write+0xf4/0x1f8
[   48.951538]        __vfs_write+0x1c/0x114
[   48.951538]        vfs_write+0xa0/0x168
[   48.951568]        SyS_write+0x3c/0x90
[   48.951568]        __sys_trace_return+0x0/0x10
[   48.951568]
               -> #0 (tk_core){----..}:
[   48.951599]        lock_acquire+0xe0/0x294
[   48.951599]        ktime_get_update_offsets_now+0x5c/0x1d4
[   48.951629]        retrigger_next_event+0x4c/0x90
[   48.951629]        on_each_cpu+0x40/0x7c
[   48.951629]        clock_was_set_work+0x14/0x20
[   48.951660]        process_one_work+0x2b4/0x808
[   48.951660]        worker_thread+0x3c/0x550
[   48.951660]        kthread+0x104/0x148
[   48.951690]        ret_from_fork+0x14/0x24
[   48.951690]
               other info that might help us debug this:

[   48.951690] Chain exists of:
                 tk_core --> &rt_b->rt_runtime_lock --> hrtimer_bases.lock

[   48.951721]  Possible unsafe locking scenario:

[   48.951721]        CPU0                    CPU1
[   48.951721]        ----                    ----
[   48.951721]   lock(hrtimer_bases.lock);
[   48.951751]                                lock(&rt_b->rt_runtime_lock);
[   48.951751]                                lock(hrtimer_bases.lock);
[   48.951751]   lock(tk_core);
[   48.951782]
                *** DEADLOCK ***

[   48.951782] 3 locks held by kworker/0:0/3:
[   48.951782]  #0:  ("events"){.+.+.+}, at: [<c0156590>] process_one_work+0x1f8/0x808
[   48.951812]  rib#1:  (hrtimer_work){+.+...}, at: [<c0156590>] process_one_work+0x1f8/0x808
[   48.951843]  rib#2:  (hrtimer_bases.lock){-.-...}, at: [<c01cc610>] retrigger_next_event+0x38/0x90
[   48.951843]   stack backtrace:
[   48.951873] CPU: 0 PID: 3 Comm: kworker/0:0 Not tainted 4.10.0-rc7-next-20170213+
[   48.951904] Workqueue: events clock_was_set_work
[   48.951904] [<c0110208>] (unwind_backtrace) from [<c010c224>] (show_stack+0x10/0x14)
[   48.951934] [<c010c224>] (show_stack) from [<c04ca6c0>] (dump_stack+0xac/0xe0)
[   48.951934] [<c04ca6c0>] (dump_stack) from [<c019b5cc>] (print_circular_bug+0x1d0/0x308)
[   48.951965] [<c019b5cc>] (print_circular_bug) from [<c019d2a8>] (validate_chain+0xf50/0x1324)
[   48.951965] [<c019d2a8>] (validate_chain) from [<c019ec18>] (__lock_acquire+0x468/0x7e8)
[   48.951995] [<c019ec18>] (__lock_acquire) from [<c019f634>] (lock_acquire+0xe0/0x294)
[   48.951995] [<c019f634>] (lock_acquire) from [<c01d0ea0>] (ktime_get_update_offsets_now+0x5c/0x1d4)
[   48.952026] [<c01d0ea0>] (ktime_get_update_offsets_now) from [<c01cc624>] (retrigger_next_event+0x4c/0x90)
[   48.952026] [<c01cc624>] (retrigger_next_event) from [<c01e4e24>] (on_each_cpu+0x40/0x7c)
[   48.952056] [<c01e4e24>] (on_each_cpu) from [<c01cafc4>] (clock_was_set_work+0x14/0x20)
[   48.952056] [<c01cafc4>] (clock_was_set_work) from [<c015664c>] (process_one_work+0x2b4/0x808)
[   48.952087] [<c015664c>] (process_one_work) from [<c0157774>] (worker_thread+0x3c/0x550)
[   48.952087] [<c0157774>] (worker_thread) from [<c015d644>] (kthread+0x104/0x148)
[   48.952087] [<c015d644>] (kthread) from [<c0107830>] (ret_from_fork+0x14/0x24)

Replace printk() with printk_deferred(), which does not call into
the scheduler.

Fixes: 0bf43f1 ("timekeeping: Prints the amounts of time spent during suspend")
Reported-and-tested-by: Tony Lindgren <[email protected]>
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: "Rafael J . Wysocki" <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: John Stultz <[email protected]>
Cc: "[4.9+]" <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Mar 31, 2017
Dmitry reported a lockdep splat [1] (false positive) that we can fix
by releasing the spinlock before calling icmp_send() from ip_expire()

This is a false positive because sending an ICMP message can not
possibly re-enter the IP frag engine.

[1]
[ INFO: possible circular locking dependency detected ]
4.10.0+ torvalds#29 Not tainted
-------------------------------------------------------
modprobe/12392 is trying to acquire lock:
 (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] spin_lock
include/linux/spinlock.h:299 [inline]
 (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] __netif_tx_lock
include/linux/netdevice.h:3486 [inline]
 (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>]
sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180

but task is already holding lock:
 (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] spin_lock
include/linux/spinlock.h:299 [inline]
 (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>]
ip_expire+0x51/0x6c0 net/ipv4/ip_fragment.c:201

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> rib#1 (&(&q->lock)->rlock){+.-...}:
       validate_chain kernel/locking/lockdep.c:2267 [inline]
       __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340
       lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151
       spin_lock include/linux/spinlock.h:299 [inline]
       ip_defrag+0x3a2/0x4130 net/ipv4/ip_fragment.c:669
       ip_check_defrag+0x4e3/0x8b0 net/ipv4/ip_fragment.c:713
       packet_rcv_fanout+0x282/0x800 net/packet/af_packet.c:1459
       deliver_skb net/core/dev.c:1834 [inline]
       dev_queue_xmit_nit+0x294/0xa90 net/core/dev.c:1890
       xmit_one net/core/dev.c:2903 [inline]
       dev_hard_start_xmit+0x16b/0xab0 net/core/dev.c:2923
       sch_direct_xmit+0x31f/0x6d0 net/sched/sch_generic.c:182
       __dev_xmit_skb net/core/dev.c:3092 [inline]
       __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358
       dev_queue_xmit+0x17/0x20 net/core/dev.c:3423
       neigh_resolve_output+0x6b9/0xb10 net/core/neighbour.c:1308
       neigh_output include/net/neighbour.h:478 [inline]
       ip_finish_output2+0x8b8/0x15a0 net/ipv4/ip_output.c:228
       ip_do_fragment+0x1d93/0x2720 net/ipv4/ip_output.c:672
       ip_fragment.constprop.54+0x145/0x200 net/ipv4/ip_output.c:545
       ip_finish_output+0x82d/0xe10 net/ipv4/ip_output.c:314
       NF_HOOK_COND include/linux/netfilter.h:246 [inline]
       ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404
       dst_output include/net/dst.h:486 [inline]
       ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124
       ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492
       ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512
       raw_sendmsg+0x26de/0x3a00 net/ipv4/raw.c:655
       inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:761
       sock_sendmsg_nosec net/socket.c:633 [inline]
       sock_sendmsg+0xca/0x110 net/socket.c:643
       ___sys_sendmsg+0x4a3/0x9f0 net/socket.c:1985
       __sys_sendmmsg+0x25c/0x750 net/socket.c:2075
       SYSC_sendmmsg net/socket.c:2106 [inline]
       SyS_sendmmsg+0x35/0x60 net/socket.c:2101
       do_syscall_64+0x2e8/0x930 arch/x86/entry/common.c:281
       return_from_SYSCALL_64+0x0/0x7a

-> #0 (_xmit_ETHER#2){+.-...}:
       check_prev_add kernel/locking/lockdep.c:1830 [inline]
       check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940
       validate_chain kernel/locking/lockdep.c:2267 [inline]
       __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340
       lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151
       spin_lock include/linux/spinlock.h:299 [inline]
       __netif_tx_lock include/linux/netdevice.h:3486 [inline]
       sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180
       __dev_xmit_skb net/core/dev.c:3092 [inline]
       __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358
       dev_queue_xmit+0x17/0x20 net/core/dev.c:3423
       neigh_hh_output include/net/neighbour.h:468 [inline]
       neigh_output include/net/neighbour.h:476 [inline]
       ip_finish_output2+0xf6c/0x15a0 net/ipv4/ip_output.c:228
       ip_finish_output+0xa29/0xe10 net/ipv4/ip_output.c:316
       NF_HOOK_COND include/linux/netfilter.h:246 [inline]
       ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404
       dst_output include/net/dst.h:486 [inline]
       ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124
       ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492
       ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512
       icmp_push_reply+0x372/0x4d0 net/ipv4/icmp.c:394
       icmp_send+0x156c/0x1c80 net/ipv4/icmp.c:754
       ip_expire+0x40e/0x6c0 net/ipv4/ip_fragment.c:239
       call_timer_fn+0x241/0x820 kernel/time/timer.c:1268
       expire_timers kernel/time/timer.c:1307 [inline]
       __run_timers+0x960/0xcf0 kernel/time/timer.c:1601
       run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614
       __do_softirq+0x31f/0xbe7 kernel/softirq.c:284
       invoke_softirq kernel/softirq.c:364 [inline]
       irq_exit+0x1cc/0x200 kernel/softirq.c:405
       exiting_irq arch/x86/include/asm/apic.h:657 [inline]
       smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962
       apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:707
       __read_once_size include/linux/compiler.h:254 [inline]
       atomic_read arch/x86/include/asm/atomic.h:26 [inline]
       rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:350 [inline]
       __rcu_is_watching kernel/rcu/tree.c:1133 [inline]
       rcu_is_watching+0x83/0x110 kernel/rcu/tree.c:1147
       rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:293
       radix_tree_deref_slot include/linux/radix-tree.h:238 [inline]
       filemap_map_pages+0x6d4/0x1570 mm/filemap.c:2335
       do_fault_around mm/memory.c:3231 [inline]
       do_read_fault mm/memory.c:3265 [inline]
       do_fault+0xbd5/0x2080 mm/memory.c:3370
       handle_pte_fault mm/memory.c:3600 [inline]
       __handle_mm_fault+0x1062/0x2cb0 mm/memory.c:3714
       handle_mm_fault+0x1e2/0x480 mm/memory.c:3751
       __do_page_fault+0x4f6/0xb60 arch/x86/mm/fault.c:1397
       do_page_fault+0x54/0x70 arch/x86/mm/fault.c:1460
       page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1011

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&(&q->lock)->rlock);
                               lock(_xmit_ETHER#2);
                               lock(&(&q->lock)->rlock);
  lock(_xmit_ETHER#2);

 *** DEADLOCK ***

10 locks held by modprobe/12392:
 #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff81329758>]
__do_page_fault+0x2b8/0xb60 arch/x86/mm/fault.c:1336
 rib#1:  (rcu_read_lock){......}, at: [<ffffffff8188cab6>]
filemap_map_pages+0x1e6/0x1570 mm/filemap.c:2324
 rib#2:  (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>]
spin_lock include/linux/spinlock.h:299 [inline]
 rib#2:  (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>]
pte_alloc_one_map mm/memory.c:2944 [inline]
 rib#2:  (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>]
alloc_set_pte+0x13b8/0x1b90 mm/memory.c:3072
 rib#3:  (((&q->timer))){+.-...}, at: [<ffffffff81627e72>]
lockdep_copy_map include/linux/lockdep.h:175 [inline]
 rib#3:  (((&q->timer))){+.-...}, at: [<ffffffff81627e72>]
call_timer_fn+0x1c2/0x820 kernel/time/timer.c:1258
 rib#4:  (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] spin_lock
include/linux/spinlock.h:299 [inline]
 rib#4:  (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>]
ip_expire+0x51/0x6c0 net/ipv4/ip_fragment.c:201
 rib#5:  (rcu_read_lock){......}, at: [<ffffffff8389a633>]
ip_expire+0x1b3/0x6c0 net/ipv4/ip_fragment.c:216
 rib#6:  (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] spin_trylock
include/linux/spinlock.h:309 [inline]
 rib#6:  (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] icmp_xmit_lock
net/ipv4/icmp.c:219 [inline]
 rib#6:  (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>]
icmp_send+0x803/0x1c80 net/ipv4/icmp.c:681
 rib#7:  (rcu_read_lock_bh){......}, at: [<ffffffff838ab9a1>]
ip_finish_output2+0x2c1/0x15a0 net/ipv4/ip_output.c:198
 rib#8:  (rcu_read_lock_bh){......}, at: [<ffffffff836d1dee>]
__dev_queue_xmit+0x23e/0x1e60 net/core/dev.c:3324
 rib#9:  (dev->qdisc_running_key ?: &qdisc_running_key){+.....}, at:
[<ffffffff836d3a27>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3423

stack backtrace:
CPU: 0 PID: 12392 Comm: modprobe Not tainted 4.10.0+ torvalds#29
Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x2ee/0x3ef lib/dump_stack.c:52
 print_circular_bug+0x307/0x3b0 kernel/locking/lockdep.c:1204
 check_prev_add kernel/locking/lockdep.c:1830 [inline]
 check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940
 validate_chain kernel/locking/lockdep.c:2267 [inline]
 __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340
 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151
 spin_lock include/linux/spinlock.h:299 [inline]
 __netif_tx_lock include/linux/netdevice.h:3486 [inline]
 sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180
 __dev_xmit_skb net/core/dev.c:3092 [inline]
 __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3423
 neigh_hh_output include/net/neighbour.h:468 [inline]
 neigh_output include/net/neighbour.h:476 [inline]
 ip_finish_output2+0xf6c/0x15a0 net/ipv4/ip_output.c:228
 ip_finish_output+0xa29/0xe10 net/ipv4/ip_output.c:316
 NF_HOOK_COND include/linux/netfilter.h:246 [inline]
 ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404
 dst_output include/net/dst.h:486 [inline]
 ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124
 ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492
 ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512
 icmp_push_reply+0x372/0x4d0 net/ipv4/icmp.c:394
 icmp_send+0x156c/0x1c80 net/ipv4/icmp.c:754
 ip_expire+0x40e/0x6c0 net/ipv4/ip_fragment.c:239
 call_timer_fn+0x241/0x820 kernel/time/timer.c:1268
 expire_timers kernel/time/timer.c:1307 [inline]
 __run_timers+0x960/0xcf0 kernel/time/timer.c:1601
 run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614
 __do_softirq+0x31f/0xbe7 kernel/softirq.c:284
 invoke_softirq kernel/softirq.c:364 [inline]
 irq_exit+0x1cc/0x200 kernel/softirq.c:405
 exiting_irq arch/x86/include/asm/apic.h:657 [inline]
 smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962
 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:707
RIP: 0010:__read_once_size include/linux/compiler.h:254 [inline]
RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:26 [inline]
RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:350 [inline]
RIP: 0010:__rcu_is_watching kernel/rcu/tree.c:1133 [inline]
RIP: 0010:rcu_is_watching+0x83/0x110 kernel/rcu/tree.c:1147
RSP: 0000:ffff8801c391f120 EFLAGS: 00000a03 ORIG_RAX: ffffffffffffff10
RAX: dffffc0000000000 RBX: ffff8801c391f148 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 000055edd4374000 RDI: ffff8801dbe1ae0c
RBP: ffff8801c391f1a0 R08: 0000000000000002 R09: 0000000000000000
R10: dffffc0000000000 R11: 0000000000000002 R12: 1ffff10038723e25
R13: ffff8801dbe1ae00 R14: ffff8801c391f680 R15: dffffc0000000000
 </IRQ>
 rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:293
 radix_tree_deref_slot include/linux/radix-tree.h:238 [inline]
 filemap_map_pages+0x6d4/0x1570 mm/filemap.c:2335
 do_fault_around mm/memory.c:3231 [inline]
 do_read_fault mm/memory.c:3265 [inline]
 do_fault+0xbd5/0x2080 mm/memory.c:3370
 handle_pte_fault mm/memory.c:3600 [inline]
 __handle_mm_fault+0x1062/0x2cb0 mm/memory.c:3714
 handle_mm_fault+0x1e2/0x480 mm/memory.c:3751
 __do_page_fault+0x4f6/0xb60 arch/x86/mm/fault.c:1397
 do_page_fault+0x54/0x70 arch/x86/mm/fault.c:1460
 page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1011
RIP: 0033:0x7f83172f2786
RSP: 002b:00007fffe859ae80 EFLAGS: 00010293
RAX: 000055edd4373040 RBX: 00007f83175111c8 RCX: 000055edd4373238
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f8317510970
RBP: 00007fffe859afd0 R08: 0000000000000009 R09: 0000000000000000
R10: 0000000000000064 R11: 0000000000000000 R12: 000055edd4373040
R13: 0000000000000000 R14: 00007fffe859afe8 R15: 0000000000000000

Signed-off-by: Eric Dumazet <[email protected]>
Reported-by: Dmitry Vyukov <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Apr 19, 2017
Run this:

    touch file0
    for ((; ;))
    {
        mount -t cpuset xxx file0
    }

And this concurrently:

    touch file1
    for ((; ;))
    {
        mount -t cpuset xxx file1
    }

We'll trigger a warning like this:

 ------------[ cut here ]------------
 WARNING: CPU: 1 PID: 4675 at lib/percpu-refcount.c:317 percpu_ref_kill_and_confirm+0x92/0xb0
 percpu_ref_kill_and_confirm called more than once on css_release!
 CPU: 1 PID: 4675 Comm: mount Not tainted 4.11.0-rc5+ rib#5
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
 Call Trace:
  dump_stack+0x63/0x84
  __warn+0xd1/0xf0
  warn_slowpath_fmt+0x5f/0x80
  percpu_ref_kill_and_confirm+0x92/0xb0
  cgroup_kill_sb+0x95/0xb0
  deactivate_locked_super+0x43/0x70
  deactivate_super+0x46/0x60
 ...
 ---[ end trace a79f61c2a2633700 ]---

Here's a race:

  Thread A				Thread B

  cgroup1_mount()
    # alloc a new cgroup root
    cgroup_setup_root()
					cgroup1_mount()
					  # no sb yet, returns NULL
					  kernfs_pin_sb()

					  # but succeeds in getting the refcnt,
					  # so re-use cgroup root
					  percpu_ref_tryget_live()
    # alloc sb with cgroup root
    cgroup_do_mount()

  cgroup_kill_sb()
					  # alloc another sb with same root
					  cgroup_do_mount()

					cgroup_kill_sb()

We end up using the same cgroup root for two different superblocks,
so percpu_ref_kill() will be called twice on the same root when the
two superblocks are destroyed.

We should fix to make sure the superblock pinning is really successful.

Cc: [email protected] # 3.16+
Reported-by: Dmitry Vyukov <[email protected]>
Signed-off-by: Zefan Li <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Apr 26, 2017
commit f222449 upstream.

We cannot do printk() from tk_debug_account_sleep_time(), because
tk_debug_account_sleep_time() is called under tk_core seq lock.
The reason why printk() is unsafe there is that console_sem may
invoke scheduler (up()->wake_up_process()->activate_task()), which,
in turn, can return back to timekeeping code, for instance, via
get_time()->ktime_get(), deadlocking the system on tk_core seq lock.

[   48.950592] ======================================================
[   48.950622] [ INFO: possible circular locking dependency detected ]
[   48.950622] 4.10.0-rc7-next-20170213+ torvalds#101 Not tainted
[   48.950622] -------------------------------------------------------
[   48.950622] kworker/0:0/3 is trying to acquire lock:
[   48.950653]  (tk_core){----..}, at: [<c01cc624>] retrigger_next_event+0x4c/0x90
[   48.950683]
               but task is already holding lock:
[   48.950683]  (hrtimer_bases.lock){-.-...}, at: [<c01cc610>] retrigger_next_event+0x38/0x90
[   48.950714]
               which lock already depends on the new lock.

[   48.950714]
               the existing dependency chain (in reverse order) is:
[   48.950714]
               -> rib#5 (hrtimer_bases.lock){-.-...}:
[   48.950744]        _raw_spin_lock_irqsave+0x50/0x64
[   48.950775]        lock_hrtimer_base+0x28/0x58
[   48.950775]        hrtimer_start_range_ns+0x20/0x5c8
[   48.950775]        __enqueue_rt_entity+0x320/0x360
[   48.950805]        enqueue_rt_entity+0x2c/0x44
[   48.950805]        enqueue_task_rt+0x24/0x94
[   48.950836]        ttwu_do_activate+0x54/0xc0
[   48.950836]        try_to_wake_up+0x248/0x5c8
[   48.950836]        __setup_irq+0x420/0x5f0
[   48.950836]        request_threaded_irq+0xdc/0x184
[   48.950866]        devm_request_threaded_irq+0x58/0xa4
[   48.950866]        omap_i2c_probe+0x530/0x6a0
[   48.950897]        platform_drv_probe+0x50/0xb0
[   48.950897]        driver_probe_device+0x1f8/0x2cc
[   48.950897]        __driver_attach+0xc0/0xc4
[   48.950927]        bus_for_each_dev+0x6c/0xa0
[   48.950927]        bus_add_driver+0x100/0x210
[   48.950927]        driver_register+0x78/0xf4
[   48.950958]        do_one_initcall+0x3c/0x16c
[   48.950958]        kernel_init_freeable+0x20c/0x2d8
[   48.950958]        kernel_init+0x8/0x110
[   48.950988]        ret_from_fork+0x14/0x24
[   48.950988]
               -> rib#4 (&rt_b->rt_runtime_lock){-.-...}:
[   48.951019]        _raw_spin_lock+0x40/0x50
[   48.951019]        rq_offline_rt+0x9c/0x2bc
[   48.951019]        set_rq_offline.part.2+0x2c/0x58
[   48.951049]        rq_attach_root+0x134/0x144
[   48.951049]        cpu_attach_domain+0x18c/0x6f4
[   48.951049]        build_sched_domains+0xba4/0xd80
[   48.951080]        sched_init_smp+0x68/0x10c
[   48.951080]        kernel_init_freeable+0x160/0x2d8
[   48.951080]        kernel_init+0x8/0x110
[   48.951080]        ret_from_fork+0x14/0x24
[   48.951110]
               -> rib#3 (&rq->lock){-.-.-.}:
[   48.951110]        _raw_spin_lock+0x40/0x50
[   48.951141]        task_fork_fair+0x30/0x124
[   48.951141]        sched_fork+0x194/0x2e0
[   48.951141]        copy_process.part.5+0x448/0x1a20
[   48.951171]        _do_fork+0x98/0x7e8
[   48.951171]        kernel_thread+0x2c/0x34
[   48.951171]        rest_init+0x1c/0x18c
[   48.951202]        start_kernel+0x35c/0x3d4
[   48.951202]        0x8000807c
[   48.951202]
               -> rib#2 (&p->pi_lock){-.-.-.}:
[   48.951232]        _raw_spin_lock_irqsave+0x50/0x64
[   48.951232]        try_to_wake_up+0x30/0x5c8
[   48.951232]        up+0x4c/0x60
[   48.951263]        __up_console_sem+0x2c/0x58
[   48.951263]        console_unlock+0x3b4/0x650
[   48.951263]        vprintk_emit+0x270/0x474
[   48.951293]        vprintk_default+0x20/0x28
[   48.951293]        printk+0x20/0x30
[   48.951324]        kauditd_hold_skb+0x94/0xb8
[   48.951324]        kauditd_thread+0x1a4/0x56c
[   48.951324]        kthread+0x104/0x148
[   48.951354]        ret_from_fork+0x14/0x24
[   48.951354]
               -> rib#1 ((console_sem).lock){-.....}:
[   48.951385]        _raw_spin_lock_irqsave+0x50/0x64
[   48.951385]        down_trylock+0xc/0x2c
[   48.951385]        __down_trylock_console_sem+0x24/0x80
[   48.951385]        console_trylock+0x10/0x8c
[   48.951416]        vprintk_emit+0x264/0x474
[   48.951416]        vprintk_default+0x20/0x28
[   48.951416]        printk+0x20/0x30
[   48.951446]        tk_debug_account_sleep_time+0x5c/0x70
[   48.951446]        __timekeeping_inject_sleeptime.constprop.3+0x170/0x1a0
[   48.951446]        timekeeping_resume+0x218/0x23c
[   48.951477]        syscore_resume+0x94/0x42c
[   48.951477]        suspend_enter+0x554/0x9b4
[   48.951477]        suspend_devices_and_enter+0xd8/0x4b4
[   48.951507]        enter_state+0x934/0xbd4
[   48.951507]        pm_suspend+0x14/0x70
[   48.951507]        state_store+0x68/0xc8
[   48.951538]        kernfs_fop_write+0xf4/0x1f8
[   48.951538]        __vfs_write+0x1c/0x114
[   48.951538]        vfs_write+0xa0/0x168
[   48.951568]        SyS_write+0x3c/0x90
[   48.951568]        __sys_trace_return+0x0/0x10
[   48.951568]
               -> #0 (tk_core){----..}:
[   48.951599]        lock_acquire+0xe0/0x294
[   48.951599]        ktime_get_update_offsets_now+0x5c/0x1d4
[   48.951629]        retrigger_next_event+0x4c/0x90
[   48.951629]        on_each_cpu+0x40/0x7c
[   48.951629]        clock_was_set_work+0x14/0x20
[   48.951660]        process_one_work+0x2b4/0x808
[   48.951660]        worker_thread+0x3c/0x550
[   48.951660]        kthread+0x104/0x148
[   48.951690]        ret_from_fork+0x14/0x24
[   48.951690]
               other info that might help us debug this:

[   48.951690] Chain exists of:
                 tk_core --> &rt_b->rt_runtime_lock --> hrtimer_bases.lock

[   48.951721]  Possible unsafe locking scenario:

[   48.951721]        CPU0                    CPU1
[   48.951721]        ----                    ----
[   48.951721]   lock(hrtimer_bases.lock);
[   48.951751]                                lock(&rt_b->rt_runtime_lock);
[   48.951751]                                lock(hrtimer_bases.lock);
[   48.951751]   lock(tk_core);
[   48.951782]
                *** DEADLOCK ***

[   48.951782] 3 locks held by kworker/0:0/3:
[   48.951782]  #0:  ("events"){.+.+.+}, at: [<c0156590>] process_one_work+0x1f8/0x808
[   48.951812]  rib#1:  (hrtimer_work){+.+...}, at: [<c0156590>] process_one_work+0x1f8/0x808
[   48.951843]  rib#2:  (hrtimer_bases.lock){-.-...}, at: [<c01cc610>] retrigger_next_event+0x38/0x90
[   48.951843]   stack backtrace:
[   48.951873] CPU: 0 PID: 3 Comm: kworker/0:0 Not tainted 4.10.0-rc7-next-20170213+
[   48.951904] Workqueue: events clock_was_set_work
[   48.951904] [<c0110208>] (unwind_backtrace) from [<c010c224>] (show_stack+0x10/0x14)
[   48.951934] [<c010c224>] (show_stack) from [<c04ca6c0>] (dump_stack+0xac/0xe0)
[   48.951934] [<c04ca6c0>] (dump_stack) from [<c019b5cc>] (print_circular_bug+0x1d0/0x308)
[   48.951965] [<c019b5cc>] (print_circular_bug) from [<c019d2a8>] (validate_chain+0xf50/0x1324)
[   48.951965] [<c019d2a8>] (validate_chain) from [<c019ec18>] (__lock_acquire+0x468/0x7e8)
[   48.951995] [<c019ec18>] (__lock_acquire) from [<c019f634>] (lock_acquire+0xe0/0x294)
[   48.951995] [<c019f634>] (lock_acquire) from [<c01d0ea0>] (ktime_get_update_offsets_now+0x5c/0x1d4)
[   48.952026] [<c01d0ea0>] (ktime_get_update_offsets_now) from [<c01cc624>] (retrigger_next_event+0x4c/0x90)
[   48.952026] [<c01cc624>] (retrigger_next_event) from [<c01e4e24>] (on_each_cpu+0x40/0x7c)
[   48.952056] [<c01e4e24>] (on_each_cpu) from [<c01cafc4>] (clock_was_set_work+0x14/0x20)
[   48.952056] [<c01cafc4>] (clock_was_set_work) from [<c015664c>] (process_one_work+0x2b4/0x808)
[   48.952087] [<c015664c>] (process_one_work) from [<c0157774>] (worker_thread+0x3c/0x550)
[   48.952087] [<c0157774>] (worker_thread) from [<c015d644>] (kthread+0x104/0x148)
[   48.952087] [<c015d644>] (kthread) from [<c0107830>] (ret_from_fork+0x14/0x24)

Replace printk() with printk_deferred(), which does not call into
the scheduler.

Fixes: 0bf43f1 ("timekeeping: Prints the amounts of time spent during suspend")
Reported-and-tested-by: Tony Lindgren <[email protected]>
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: "Rafael J . Wysocki" <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: John Stultz <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue May 8, 2017
mipsxx_pmu_handle_shared_irq() calls irq_work_run() while holding the
pmuint_rwlock for read.  irq_work_run() can, via perf_pending_event(),
call try_to_wake_up() which can try to take rq->lock.

However, perf can also call perf_pmu_enable() (and thus take the
pmuint_rwlock for write) while holding the rq->lock, from
finish_task_switch() via perf_event_context_sched_in().

This leads to an ABBA deadlock:

 PID: 3855   TASK: 8f7ce288  CPU: 2   COMMAND: "process"
  #0 [89c39ac8] __delay at 803b5be4
  rib#1 [89c39ac8] do_raw_spin_lock at 8008fdcc
  rib#2 [89c39af8] try_to_wake_up at 8006e47c
  rib#3 [89c39b38] pollwake at 8018eab0
  rib#4 [89c39b68] __wake_up_common at 800879f4
  rib#5 [89c39b98] __wake_up at 800880e4
  rib#6 [89c39bc8] perf_event_wakeup at 8012109c
  rib#7 [89c39be8] perf_pending_event at 80121184
  rib#8 [89c39c08] irq_work_run_list at 801151f0
  rib#9 [89c39c38] irq_work_run at 80115274
 rib#10 [89c39c50] mipsxx_pmu_handle_shared_irq at 8002cc7c

 PID: 1481   TASK: 8eaac6a8  CPU: 3   COMMAND: "process"
  #0 [8de7f900] do_raw_write_lock at 800900e0
  rib#1 [8de7f918] perf_event_context_sched_in at 80122310
  rib#2 [8de7f938] __perf_event_task_sched_in at 80122608
  rib#3 [8de7f958] finish_task_switch at 8006b8a4
  rib#4 [8de7f998] __schedule at 805e4dc4
  rib#5 [8de7f9f8] schedule at 805e5558
  rib#6 [8de7fa10] schedule_hrtimeout_range_clock at 805e9984
  rib#7 [8de7fa70] poll_schedule_timeout at 8018e8f8
  rib#8 [8de7fa88] do_select at 8018f338
  rib#9 [8de7fd88] core_sys_select at 8018f5cc
 rib#10 [8de7fee0] sys_select at 8018f854
 rib#11 [8de7ff28] syscall_common at 80028fc8

The lock seems to be there to protect the hardware counters so there is
no need to hold it across irq_work_run().

Signed-off-by: Rabin Vincent <[email protected]>
Signed-off-by: Ralf Baechle <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Jun 7, 2017
MSS change on active QPs is not supported. Store new MSS
value for new QPs only. Remove code to modify MSS on the fly.
This also resolves a crash on QP modify to QP 0.

BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: i40iw_sc_qp_modify+0x22/0x280 [i40iw]
Oops: 0000 [rib#1] SMP KASAN
CPU: 2 PID: 1236 Comm: kworker/u16:4 Not tainted 4.12.0-rc1 rib#5
Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./Q87M-D2H,
BIOS F7 01/17/2014
Workqueue: l2params i40iw_l2params_worker [i40iw]
task: ffff88070f5a9b40 task.stack: ffff88070f5a0000
RIP: 0010:i40iw_sc_qp_modify+0x22/0x280 [i40iw]
...
Call Trace:
i40iw_exec_cqp_cmd+0x2ce/0x410 [i40iw]
? _raw_spin_lock_irqsave+0x6f/0x80
? i40iw_process_cqp_cmd+0x1d/0x80 [i40iw]
i40iw_process_cqp_cmd+0x7c/0x80 [i40iw]
i40iw_handle_cqp_op+0x2f/0x200 [i40iw]
? trace_hardirqs_off+0xd/0x10
? _raw_spin_unlock_irqrestore+0x46/0x50
i40iw_hw_modify_qp+0x5e/0x90 [i40iw]
i40iw_qp_mss_modify+0x52/0x60 [i40iw]
i40iw_change_l2params+0x145/0x160 [i40iw]
i40iw_l2params_worker+0x1f/0x40 [i40iw]
process_one_work+0x1f5/0x650
? process_one_work+0x161/0x650
worker_thread+0x48/0x3b0
kthread+0x112/0x150
? process_one_work+0x650/0x650
? kthread_create_on_node+0x40/0x40
ret_from_fork+0x2e/0x40
Code: 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 56 41 55 41 89 cd 41 54 49 89 fc
53 48 89 f3 48 89 d6 48 83 ec 08 48 8b 87 10 01 00 00 <48> 8b 40 08 4c 8b b0 40 04
00 00 4c 89 f7 e8 1b e5 ff ff 48 85
RIP: i40iw_sc_qp_modify+0x22/0x280 [i40iw] RSP: ffff88070f5a7c28
CR2: 0000000000000008
---[ end trace 77a405931e296060 ]---

Reported-by: Stefan Assmann <[email protected]>
Signed-off-by: Shiraz Saleem <[email protected]>
Signed-off-by: Doug Ledford <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Jun 20, 2017
'perf annotate' is dropping the cr* fields from branch instructions.

Fix it by adding support to display branch instructions having
multiple operands.

Power Arch objdump of int_sqrt:

 20.36 | c0000000004d2694:   subf   r10,r10,r3
       | c0000000004d2698: v bgt    cr6,c0000000004d26a0 <int_sqrt+0x40>
  1.82 | c0000000004d269c:   mr     r3,r10
 29.18 | c0000000004d26a0:   mr     r10,r8
       | c0000000004d26a4: v bgt    cr7,c0000000004d26ac <int_sqrt+0x4c>
       | c0000000004d26a8:   mr     r10,r7

Power Arch Before Patch:

 20.36 |       subf   r10,r10,r3
       |     v bgt    40
  1.82 |       mr     r3,r10
 29.18 | 40:   mr     r10,r8
       |     v bgt    4c
       |       mr     r10,r7

Power Arch After patch:

 20.36 |       subf   r10,r10,r3
       |     v bgt    cr6,40
  1.82 |       mr     r3,r10
 29.18 | 40:   mr     r10,r8
       |     v bgt    cr7,4c
       |       mr     r10,r7

Also support AArch64 conditional branch instructions, which can
have up to three operands:

Aarch64 Non-simplified (raw objdump) view:

       │ffff0000083cd11c: ↑ cbz    w0, ffff0000083cd100 <security_fil▒
...
  4.44 │ffff000│083cd134: ↓ tbnz   w0, torvalds#26, ffff0000083cd190 <securit▒
...
  1.37 │ffff000│083cd144: ↓ tbnz   w22, rib#5, ffff0000083cd1a4 <securit▒
       │ffff000│083cd148:   mov    w19, #0x20000                   //▒
  1.02 │ffff000│083cd14c: ↓ tbz    w22, rib#2, ffff0000083cd1ac <securit▒
...
  0.68 │ffff000└──3cd16c: ↑ cbnz   w0, ffff0000083cd120 <security_fil▒

Aarch64 Simplified, before this patch:

       │    ↑ cbz    40
...
  4.44 │   │↓ tbnz   w0, torvalds#26, ffff0000083cd190 <security_file_permiss▒
...
  1.37 │   │↓ tbnz   w22, rib#5, ffff0000083cd1a4 <security_file_permiss▒
       │   │  mov    w19, #0x20000                   // #131072
  1.02 │   │↓ tbz    w22, rib#2, ffff0000083cd1ac <security_file_permiss▒
...
  0.68 │   └──cbnz   60

the cbz operand is missing, and the tbz doesn't get simplified processing
at all because the parsing function failed to match an address.

Aarch64 Simplified, After this patch applied:

       │    ↑ cbz    w0, 40
...
  4.44 │   │↓ tbnz   w0, torvalds#26, d0
...
  1.37 │   │↓ tbnz   w22, rib#5, e4
       │   │  mov    w19, #0x20000                   // #131072
  1.02 │   │↓ tbz    w22, rib#2, ec
...
  0.68 │   └──cbnz   w0, 60

Originally-by: Ravi Bangoria <[email protected]>
Tested-by: Ravi Bangoria <[email protected]>
Reported-by: Anton Blanchard <[email protected]>
Reported-by: Robin Murphy <[email protected]>
Signed-off-by: Kim Phillips <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Taeung Song <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Jun 20, 2017
A NULL-pointer dereference bug in gadgetfs was uncovered by syzkaller:

> kasan: GPF could be caused by NULL-ptr deref or user memory access
> general protection fault: 0000 [rib#1] SMP KASAN
> Dumping ftrace buffer:
>    (ftrace buffer empty)
> Modules linked in:
> CPU: 2 PID: 4820 Comm: syz-executor0 Not tainted 4.12.0-rc4+ rib#5
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> task: ffff880039542dc0 task.stack: ffff88003bdd0000
> RIP: 0010:__list_del_entry_valid+0x7e/0x170 lib/list_debug.c:51
> RSP: 0018:ffff88003bdd6e50 EFLAGS: 00010246
> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000010000
> RDX: 0000000000000000 RSI: ffffffff86504948 RDI: ffffffff86504950
> RBP: ffff88003bdd6e68 R08: ffff880039542dc0 R09: ffffffff8778ce00
> R10: ffff88003bdd6e68 R11: dffffc0000000000 R12: 0000000000000000
> R13: dffffc0000000000 R14: 1ffff100077badd2 R15: ffffffff864d2e40
> FS:  0000000000000000(0000) GS:ffff88006dc00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000000002014aff9 CR3: 0000000006022000 CR4: 00000000000006e0
> Call Trace:
>  __list_del_entry include/linux/list.h:116 [inline]
>  list_del include/linux/list.h:124 [inline]
>  usb_gadget_unregister_driver+0x166/0x4c0 drivers/usb/gadget/udc/core.c:1387
>  dev_release+0x80/0x160 drivers/usb/gadget/legacy/inode.c:1187
>  __fput+0x332/0x7f0 fs/file_table.c:209
>  ____fput+0x15/0x20 fs/file_table.c:245
>  task_work_run+0x19b/0x270 kernel/task_work.c:116
>  exit_task_work include/linux/task_work.h:21 [inline]
>  do_exit+0x18a3/0x2820 kernel/exit.c:878
>  do_group_exit+0x149/0x420 kernel/exit.c:982
>  get_signal+0x77f/0x1780 kernel/signal.c:2318
>  do_signal+0xd2/0x2130 arch/x86/kernel/signal.c:808
>  exit_to_usermode_loop+0x1a7/0x240 arch/x86/entry/common.c:157
>  prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
>  syscall_return_slowpath+0x3ba/0x410 arch/x86/entry/common.c:263
>  entry_SYSCALL_64_fastpath+0xbc/0xbe
> RIP: 0033:0x4461f9
> RSP: 002b:00007fdac2b1ecf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
> RAX: fffffffffffffe00 RBX: 00000000007080c8 RCX: 00000000004461f9
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000007080c8
> RBP: 00000000007080a8 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 0000000000000000 R14: 00007fdac2b1f9c0 R15: 00007fdac2b1f700
> Code: 00 00 00 00 ad de 49 39 c4 74 6a 48 b8 00 02 00 00 00 00 ad de
> 48 89 da 48 39 c3 74 74 48 c1 ea 03 48 b8 00 00 00 00 00 fc ff df <80>
> 3c 02 00 0f 85 92 00 00 00 48 8b 13 48 39 f2 75 66 49 8d 7c
> RIP: __list_del_entry_valid+0x7e/0x170 lib/list_debug.c:51 RSP: ffff88003bdd6e50
> ---[ end trace 30e94b1eec4831c8 ]---
> Kernel panic - not syncing: Fatal exception

The bug was caused by dev_release() failing to turn off its
gadget_registered flag after unregistering the gadget driver.  As a
result, when a later user closed the device file before writing a
valid set of descriptors, dev_release() thought the gadget had been
registered and tried to unregister it, even though it had not been.
This led to the NULL pointer dereference.

The fix is simple: turn off the flag when the gadget is unregistered.

Signed-off-by: Alan Stern <[email protected]>
Reported-and-tested-by: Andrey Konovalov <[email protected]>
CC: <[email protected]>
Signed-off-by: Felipe Balbi <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Jun 20, 2017
Fix the following kernel bug:

kernel BUG at drivers/iommu/intel-iommu.c:3260!
invalid opcode: 0000 [rib#5] PREEMPT SMP
Hardware name: Intel Corp. Harcuvar/Server, BIOS HAVLCRB0.X64.0013.D39.1608311820 08/31/2016
task: ffff880175389950 ti: ffff880176bec000 task.ti: ffff880176bec000
RIP: 0010:[<ffffffff8150a83b>]  [<ffffffff8150a83b>] intel_unmap+0x25b/0x260
RSP: 0018:ffff880176bef5e8  EFLAGS: 00010296
RAX: 0000000000000024 RBX: ffff8800773c7c88 RCX: 000000000000ce04
RDX: 0000000080000000 RSI: 0000000000000000 RDI: 0000000000000009
RBP: ffff880176bef638 R08: 0000000000000010 R09: 0000000000000004
R10: ffff880175389c78 R11: 0000000000000a4f R12: ffff8800773c7868
R13: 00000000ffffac88 R14: ffff8800773c7818 R15: 0000000000000001
FS:  00007fef21258700(0000) GS:ffff88017b5c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000066d6d8 CR3: 000000007118c000 CR4: 00000000003406e0
Stack:
 00000000ffffac88 ffffffff8199867f ffff880176bef5f8 ffff880100000030
 ffff880176bef668 ffff8800773c7c88 ffff880178288098 ffff8800772c0010
 ffff8800773c7818 0000000000000001 ffff880176bef648 ffffffff8150a86e
Call Trace:
 [<ffffffff8199867f>] ? printk+0x46/0x48
 [<ffffffff8150a86e>] intel_unmap_page+0xe/0x10
 [<ffffffffa039d99b>] ismt_access+0x27b/0x8fa [i2c_ismt]
 [<ffffffff81554420>] ? __pm_runtime_suspend+0xa0/0xa0
 [<ffffffff815544a0>] ? pm_suspend_timer_fn+0x80/0x80
 [<ffffffff81554420>] ? __pm_runtime_suspend+0xa0/0xa0
 [<ffffffff815544a0>] ? pm_suspend_timer_fn+0x80/0x80
 [<ffffffff8143dfd0>] ? pci_bus_read_dev_vendor_id+0xf0/0xf0
 [<ffffffff8172b36c>] i2c_smbus_xfer+0xec/0x4b0
 [<ffffffff810aa4d5>] ? vprintk_emit+0x345/0x530
 [<ffffffffa038936b>] i2cdev_ioctl_smbus+0x12b/0x240 [i2c_dev]
 [<ffffffff810aa829>] ? vprintk_default+0x29/0x40
 [<ffffffffa0389b33>] i2cdev_ioctl+0x63/0x1ec [i2c_dev]
 [<ffffffff811b04c8>] do_vfs_ioctl+0x328/0x5d0
 [<ffffffff8119d8ec>] ? vfs_write+0x11c/0x190
 [<ffffffff8109d449>] ? rt_up_read+0x19/0x20
 [<ffffffff811b07f1>] SyS_ioctl+0x81/0xa0
 [<ffffffff819a351b>] system_call_fastpath+0x16/0x6e

This happen When run "i2cdetect -y 0" detect SMBus iSMT adapter.

After finished I2C block read/write, when unmap the data buffer,
a wrong device address was pass to dma_unmap_single().

To fix this, give dma_unmap_single() the "dev" parameter, just like
what dma_map_single() does, then unmap can find the right devices.

Fixes: 13f35ac ("i2c: Adding support for Intel iSMT SMBus 2.0 host controller")
Signed-off-by: Liwei Song <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Aug 2, 2017
With a misbehaving controller it's possible we'll never
enter the live state and create an admin queue. When we
fail out of reset work it's possible we failed out early
enough without setting up the admin queue. We tear down
queues after a failed reset, but needed to do some more
sanitization.

Fixes 443bd90: "nvme: host: unquiesce queue in nvme_kill_queues()"

[  189.650995] nvme nvme1: pci function 0000:0b:00.0
[  317.680055] nvme nvme0: Device not ready; aborting reset
[  317.680183] nvme nvme0: Removing after probe failure status: -19
[  317.681258] kasan: GPF could be caused by NULL-ptr deref or user memory access
[  317.681397] general protection fault: 0000 [rib#1] SMP KASAN
[  317.682984] CPU: 3 PID: 477 Comm: kworker/3:2 Not tainted 4.13.0-rc1+ rib#5
[  317.683112] Hardware name: Gigabyte Technology Co., Ltd. Z170X-UD5/Z170X-UD5-CF, BIOS F5 03/07/2016
[  317.683284] Workqueue: events nvme_remove_dead_ctrl_work [nvme]
[  317.683398] task: ffff8803b0990000 task.stack: ffff8803c2ef0000
[  317.683516] RIP: 0010:blk_mq_unquiesce_queue+0x2b/0xa0
[  317.683614] RSP: 0018:ffff8803c2ef7d40 EFLAGS: 00010282
[  317.683716] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff1006fbdcde3
[  317.683847] RDX: 0000000000000038 RSI: 1ffff1006f5a9245 RDI: 0000000000000000
[  317.683978] RBP: ffff8803c2ef7d58 R08: 1ffff1007bcdc974 R09: 0000000000000000
[  317.684108] R10: 1ffff1007bcdc975 R11: 0000000000000000 R12: 00000000000001c0
[  317.684239] R13: ffff88037ad49228 R14: ffff88037ad492d0 R15: ffff88037ad492e0
[  317.684371] FS:  0000000000000000(0000) GS:ffff8803de6c0000(0000) knlGS:0000000000000000
[  317.684519] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  317.684627] CR2: 0000002d1860c000 CR3: 000000045b40d000 CR4: 00000000003406e0
[  317.684758] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  317.684888] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  317.685018] Call Trace:
[  317.685084]  nvme_kill_queues+0x4d/0x170 [nvme_core]
[  317.685185]  nvme_remove_dead_ctrl_work+0x3a/0x90 [nvme]
[  317.685289]  process_one_work+0x771/0x1170
[  317.685372]  worker_thread+0xde/0x11e0
[  317.685452]  ? pci_mmcfg_check_reserved+0x110/0x110
[  317.685550]  kthread+0x2d3/0x3d0
[  317.685617]  ? process_one_work+0x1170/0x1170
[  317.685704]  ? kthread_create_on_node+0xc0/0xc0
[  317.685785]  ret_from_fork+0x25/0x30
[  317.685798] Code: 0f 1f 44 00 00 55 48 b8 00 00 00 00 00 fc ff df 48 89 e5 41 54 4c 8d a7 c0 01 00 00 53 48 89 fb 4c 89 e2 48 c1 ea 03 48 83 ec 08 <80> 3c 02 00 75 50 48 8b bb c0 01 00 00 e8 33 8a f9 00 0f ba b3
[  317.685872] RIP: blk_mq_unquiesce_queue+0x2b/0xa0 RSP: ffff8803c2ef7d40
[  317.685908] ---[ end trace a3f8704150b1e8b4 ]---

Signed-off-by: Scott Bauer <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Oct 26, 2017
Thomas reported that 'perf buildid-list' gets a SEGFAULT due to NULL
pointer deref when he ran it on a data with namespace events.  It was
because the buildid_id__mark_dso_hit_ops lacks the namespace event
handler and perf_too__fill_default() didn't set it.

  Program received signal SIGSEGV, Segmentation fault.
  0x0000000000000000 in ?? ()
  Missing separate debuginfos, use: dnf debuginfo-install audit-libs-2.7.7-1.fc25.s390x bzip2-libs-1.0.6-21.fc25.s390x elfutils-libelf-0.169-1.fc25.s390x
  +elfutils-libs-0.169-1.fc25.s390x libcap-ng-0.7.8-1.fc25.s390x numactl-libs-2.0.11-2.ibm.fc25.s390x openssl-libs-1.1.0e-1.1.ibm.fc25.s390x perl-libs-5.24.1-386.fc25.s390x
  +python-libs-2.7.13-2.fc25.s390x slang-2.3.0-7.fc25.s390x xz-libs-5.2.3-2.fc25.s390x zlib-1.2.8-10.fc25.s390x
  (gdb) where
  #0  0x0000000000000000 in ?? ()
  rib#1  0x00000000010fad6a in machines__deliver_event (machines=<optimized out>, machines@entry=0x2c6fd18,
      evlist=<optimized out>, event=event@entry=0x3fffdf00470, sample=0x3ffffffe880, sample@entry=0x3ffffffe888,
      tool=tool@entry=0x1312968 <build_id.mark_dso_hit_ops>, file_offset=1136) at util/session.c:1287
  rib#2  0x00000000010fbf4e in perf_session__deliver_event (file_offset=1136, tool=0x1312968 <build_id.mark_dso_hit_ops>,
      sample=0x3ffffffe888, event=0x3fffdf00470, session=0x2c6fc30) at util/session.c:1340
  rib#3  perf_session__process_event (session=0x2c6fc30, session@entry=0x0, event=event@entry=0x3fffdf00470,
      file_offset=file_offset@entry=1136) at util/session.c:1522
  rib#4  0x00000000010fddde in __perf_session__process_events (file_size=11880, data_size=<optimized out>,
      data_offset=<optimized out>, session=0x0) at util/session.c:1899
  rib#5  perf_session__process_events (session=0x0, session@entry=0x2c6fc30) at util/session.c:1953
  rib#6  0x000000000103b2ac in perf_session__list_build_ids (with_hits=<optimized out>, force=<optimized out>)
      at builtin-buildid-list.c:83
  rib#7  cmd_buildid_list (argc=<optimized out>, argv=<optimized out>) at builtin-buildid-list.c:115
  rib#8  0x00000000010a026c in run_builtin (p=0x1311f78 <commands+24>, argc=argc@entry=2, argv=argv@entry=0x3fffffff3c0)
      at perf.c:296
  rib#9  0x000000000102bc00 in handle_internal_command (argv=<optimized out>, argc=2) at perf.c:348
  rib#10 run_argv (argcp=<synthetic pointer>, argv=<synthetic pointer>) at perf.c:392
  rib#11 main (argc=<optimized out>, argv=0x3fffffff3c0) at perf.c:536
  (gdb)

Fix it by adding a stub event handler for namespace event.

Committer testing:

Further clarifying, plain using 'perf buildid-list' will not end up in a
SEGFAULT when processing a perf.data file with namespace info:

  # perf record -a --namespaces sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 2.024 MB perf.data (1058 samples) ]
  # perf buildid-list | wc -l
  38
  # perf buildid-list | head -5
  e2a171c7b905826fc8494f0711ba76ab6abbd604 /lib/modules/4.14.0-rc3+/build/vmlinux
  874840a02d8f8a31cedd605d0b8653145472ced3 /lib/modules/4.14.0-rc3+/kernel/arch/x86/kvm/kvm-intel.ko
  ea7223776730cd8a22f320040aae4d54312984bc /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/i915/i915.ko
  5961535e6732a8edb7f22b3f148bb2fa2e0be4b9 /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/drm.ko
  f045f54aa78cf1931cc893f78b6cbc52c72a8cb1 /usr/lib64/libc-2.25.so
  #

It is only when one asks for checking what of those entries actually had
samples, i.e. when we use either -H or --with-hits, that we will process
all the PERF_RECORD_ events, and since tools/perf/builtin-buildid-list.c
neither explicitely set a perf_tool.namespaces() callback nor the
default stub was set that we end up, when processing a
PERF_RECORD_NAMESPACE record, causing a SEGFAULT:

  # perf buildid-list -H
  Segmentation fault (core dumped)
  ^C
  #

Reported-and-Tested-by: Thomas-Mich Richter <[email protected]>
Signed-off-by: Namhyung Kim <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Hari Bathini <[email protected]>
Cc: Hendrik Brueckner <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas-Mich Richter <[email protected]>
Fixes: f3b3614 ("perf tools: Add PERF_RECORD_NAMESPACES to include namespaces related info")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Nov 2, 2017
v4.10 commit 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN
recovery") extended accessing parent pointer fields of struct
zfcp_erp_action for tracing.  If an erp_action has never been enqueued
before, these parent pointer fields are uninitialized and NULL. Examples
are zfcp objects freshly added to the parent object's children list,
before enqueueing their first recovery subsequently. In
zfcp_erp_try_rport_unblock(), we iterate such list. Accessing erp_action
fields can cause a NULL pointer dereference.  Since the kernel can read
from lowcore on s390, it does not immediately cause a kernel page
fault. Instead it can cause hangs on trying to acquire the wrong
erp_action->adapter->dbf->rec_lock in zfcp_dbf_rec_action_lvl()
                      ^bogus^
while holding already other locks with IRQs disabled.

Real life example from attaching lots of LUNs in parallel on many CPUs:

crash> bt 17723
PID: 17723  TASK: ...               CPU: 25  COMMAND: "zfcperp0.0.1800"
 LOWCORE INFO:
  -psw      : 0x0404300180000000 0x000000000038e424
  -function : _raw_spin_lock_wait_flags at 38e424
...
 #0 [fdde8fc90] zfcp_dbf_rec_action_lvl at 3e0004e9862 [zfcp]
 rib#1 [fdde8fce8] zfcp_erp_try_rport_unblock at 3e0004dfddc [zfcp]
 rib#2 [fdde8fd38] zfcp_erp_strategy at 3e0004e0234 [zfcp]
 rib#3 [fdde8fda8] zfcp_erp_thread at 3e0004e0a12 [zfcp]
 rib#4 [fdde8fe60] kthread at 173550
 rib#5 [fdde8feb8] kernel_thread_starter at 10add2

zfcp_adapter
 zfcp_port
  zfcp_unit <address>, 0x404040d600000000
  scsi_device NULL, returning early!
zfcp_scsi_dev.status = 0x40000000
0x40000000 ZFCP_STATUS_COMMON_RUNNING

crash> zfcp_unit <address>
struct zfcp_unit {
  erp_action = {
    adapter = 0x0,
    port = 0x0,
    unit = 0x0,
  },
}

zfcp_erp_action is always fully embedded into its container object. Such
container object is never moved in its object tree (only add or delete).
Hence, erp_action parent pointers can never change.

To fix the issue, initialize the erp_action parent pointers before
adding the erp_action container to any list and thus before it becomes
accessible from outside of its initializing function.

In order to also close the time window between zfcp_erp_setup_act()
memsetting the entire erp_action to zero and setting the parent pointers
again, drop the memset and instead explicitly initialize individually
all erp_action fields except for parent pointers. To be extra careful
not to introduce any other unintended side effect, even keep zeroing the
erp_action fields for list and timer. Also double-check with
WARN_ON_ONCE that erp_action parent pointers never change, so we get to
know when we would deviate from previous behavior.

Signed-off-by: Steffen Maier <[email protected]>
Fixes: 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery")
Cc: <[email protected]> rib#2.6.32+
Reviewed-by: Benjamin Block <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Nov 3, 2017
…ug deadlock

4.14-rc1 gained the fancy new cross-release support in lockdep, which
seems to have uncovered a few more rules about what is allowed and
isn't.

This one here seems to indicate that allocating a work-queue while
holding mmap_sem is a no-go, so let's try to preallocate it.

Of course another way to break this chain would be somewhere in the
cpu hotplug code, since this isn't the only trace we're finding now
which goes through msr_create_device.

Full lockdep splat:

======================================================
WARNING: possible circular locking dependency detected
4.14.0-rc1-CI-CI_DRM_3118+ rib#1 Tainted: G     U
------------------------------------------------------
prime_mmap/1551 is trying to acquire lock:
 (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffff8109dbb7>] apply_workqueue_attrs+0x17/0x50

but task is already holding lock:
 (&dev_priv->mm_lock){+.+.}, at: [<ffffffffa01a7b2a>] i915_gem_userptr_init__mmu_notifier+0x14a/0x270 [i915]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> rib#6 (&dev_priv->mm_lock){+.+.}:
       __lock_acquire+0x1420/0x15e0
       lock_acquire+0xb0/0x200
       __mutex_lock+0x86/0x9b0
       mutex_lock_nested+0x1b/0x20
       i915_gem_userptr_init__mmu_notifier+0x14a/0x270 [i915]
       i915_gem_userptr_ioctl+0x222/0x2c0 [i915]
       drm_ioctl_kernel+0x69/0xb0
       drm_ioctl+0x2f9/0x3d0
       do_vfs_ioctl+0x94/0x670
       SyS_ioctl+0x41/0x70
       entry_SYSCALL_64_fastpath+0x1c/0xb1

-> rib#5 (&mm->mmap_sem){++++}:
       __lock_acquire+0x1420/0x15e0
       lock_acquire+0xb0/0x200
       __might_fault+0x68/0x90
       _copy_to_user+0x23/0x70
       filldir+0xa5/0x120
       dcache_readdir+0xf9/0x170
       iterate_dir+0x69/0x1a0
       SyS_getdents+0xa5/0x140
       entry_SYSCALL_64_fastpath+0x1c/0xb1

-> rib#4 (&sb->s_type->i_mutex_key#5){++++}:
       down_write+0x3b/0x70
       handle_create+0xcb/0x1e0
       devtmpfsd+0x139/0x180
       kthread+0x152/0x190
       ret_from_fork+0x27/0x40

-> rib#3 ((complete)&req.done){+.+.}:
       __lock_acquire+0x1420/0x15e0
       lock_acquire+0xb0/0x200
       wait_for_common+0x58/0x210
       wait_for_completion+0x1d/0x20
       devtmpfs_create_node+0x13d/0x160
       device_add+0x5eb/0x620
       device_create_groups_vargs+0xe0/0xf0
       device_create+0x3a/0x40
       msr_device_create+0x2b/0x40
       cpuhp_invoke_callback+0xa3/0x840
       cpuhp_thread_fun+0x7a/0x150
       smpboot_thread_fn+0x18a/0x280
       kthread+0x152/0x190
       ret_from_fork+0x27/0x40

-> rib#2 (cpuhp_state){+.+.}:
       __lock_acquire+0x1420/0x15e0
       lock_acquire+0xb0/0x200
       cpuhp_issue_call+0x10b/0x170
       __cpuhp_setup_state_cpuslocked+0x134/0x2a0
       __cpuhp_setup_state+0x46/0x60
       page_writeback_init+0x43/0x67
       pagecache_init+0x3d/0x42
       start_kernel+0x3a8/0x3fc
       x86_64_start_reservations+0x2a/0x2c
       x86_64_start_kernel+0x6d/0x70
       verify_cpu+0x0/0xfb

-> rib#1 (cpuhp_state_mutex){+.+.}:
       __lock_acquire+0x1420/0x15e0
       lock_acquire+0xb0/0x200
       __mutex_lock+0x86/0x9b0
       mutex_lock_nested+0x1b/0x20
       __cpuhp_setup_state_cpuslocked+0x52/0x2a0
       __cpuhp_setup_state+0x46/0x60
       page_alloc_init+0x28/0x30
       start_kernel+0x145/0x3fc
       x86_64_start_reservations+0x2a/0x2c
       x86_64_start_kernel+0x6d/0x70
       verify_cpu+0x0/0xfb

-> #0 (cpu_hotplug_lock.rw_sem){++++}:
       check_prev_add+0x430/0x840
       __lock_acquire+0x1420/0x15e0
       lock_acquire+0xb0/0x200
       cpus_read_lock+0x3d/0xb0
       apply_workqueue_attrs+0x17/0x50
       __alloc_workqueue_key+0x1d8/0x4d9
       i915_gem_userptr_init__mmu_notifier+0x1fb/0x270 [i915]
       i915_gem_userptr_ioctl+0x222/0x2c0 [i915]
       drm_ioctl_kernel+0x69/0xb0
       drm_ioctl+0x2f9/0x3d0
       do_vfs_ioctl+0x94/0x670
       SyS_ioctl+0x41/0x70
       entry_SYSCALL_64_fastpath+0x1c/0xb1

other info that might help us debug this:

Chain exists of:
  cpu_hotplug_lock.rw_sem --> &mm->mmap_sem --> &dev_priv->mm_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&dev_priv->mm_lock);
                               lock(&mm->mmap_sem);
                               lock(&dev_priv->mm_lock);
  lock(cpu_hotplug_lock.rw_sem);

 *** DEADLOCK ***

2 locks held by prime_mmap/1551:
 #0:  (&mm->mmap_sem){++++}, at: [<ffffffffa01a7b18>] i915_gem_userptr_init__mmu_notifier+0x138/0x270 [i915]
 rib#1:  (&dev_priv->mm_lock){+.+.}, at: [<ffffffffa01a7b2a>] i915_gem_userptr_init__mmu_notifier+0x14a/0x270 [i915]

stack backtrace:
CPU: 4 PID: 1551 Comm: prime_mmap Tainted: G     U          4.14.0-rc1-CI-CI_DRM_3118+ rib#1
Hardware name: Dell Inc. XPS 8300  /0Y2MRG, BIOS A06 10/17/2011
Call Trace:
 dump_stack+0x68/0x9f
 print_circular_bug+0x235/0x3c0
 ? lockdep_init_map_crosslock+0x20/0x20
 check_prev_add+0x430/0x840
 __lock_acquire+0x1420/0x15e0
 ? __lock_acquire+0x1420/0x15e0
 ? lockdep_init_map_crosslock+0x20/0x20
 lock_acquire+0xb0/0x200
 ? apply_workqueue_attrs+0x17/0x50
 cpus_read_lock+0x3d/0xb0
 ? apply_workqueue_attrs+0x17/0x50
 apply_workqueue_attrs+0x17/0x50
 __alloc_workqueue_key+0x1d8/0x4d9
 ? __lockdep_init_map+0x57/0x1c0
 i915_gem_userptr_init__mmu_notifier+0x1fb/0x270 [i915]
 i915_gem_userptr_ioctl+0x222/0x2c0 [i915]
 ? i915_gem_userptr_release+0x140/0x140 [i915]
 drm_ioctl_kernel+0x69/0xb0
 drm_ioctl+0x2f9/0x3d0
 ? i915_gem_userptr_release+0x140/0x140 [i915]
 ? __do_page_fault+0x2a4/0x570
 do_vfs_ioctl+0x94/0x670
 ? entry_SYSCALL_64_fastpath+0x5/0xb1
 ? __this_cpu_preempt_check+0x13/0x20
 ? trace_hardirqs_on_caller+0xe3/0x1b0
 SyS_ioctl+0x41/0x70
 entry_SYSCALL_64_fastpath+0x1c/0xb1
RIP: 0033:0x7fbb83c39587
RSP: 002b:00007fff188dc228 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: ffffffff81492963 RCX: 00007fbb83c39587
RDX: 00007fff188dc260 RSI: 00000000c0186473 RDI: 0000000000000003
RBP: ffffc90001487f88 R08: 0000000000000000 R09: 00007fff188dc2ac
R10: 00007fbb83efcb58 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000003 R14: 00000000c0186473 R15: 00007fff188dc2ac
 ? __this_cpu_preempt_check+0x13/0x20

Note that this also has the minor benefit of slightly reducing the
critical section where we hold mmap_sem.

v2: Set ret correctly when we raced with another thread.

v3: Use Chris' diff. Attach the right lockdep splat.

v4: Repaint in Tvrtko's colors (aka don't report ENOMEM if we race and
some other thread managed to not also get an ENOMEM and successfully
install the mmu notifier. Note that the kernel guarantees that small
allocations succeed, so this never actually happens).

Cc: Chris Wilson <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Sasha Levin <[email protected]>
Cc: Marta Lofstedt <[email protected]>
Cc: Tejun Heo <[email protected]>
References: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_3180/shard-hsw3/igt@prime_mmap@test_userptr.html
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102939
Reviewed-by: Tvrtko Ursulin <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
matt-auld pushed a commit to matt-auld/linux that referenced this issue Nov 3, 2017
stop_machine is not really a locking primitive we should use, except
when the hw folks tell us the hw is broken and that's the only way to
work around it.

This patch tries to address the locking abuse of stop_machine() from

commit 20e4933
Author: Chris Wilson <[email protected]>
Date:   Tue Nov 22 14:41:21 2016 +0000

    drm/i915: Stop the machine as we install the wedged submit_request handler

Chris said parts of the reasons for going with stop_machine() was that
it's no overhead for the fast-path. But these callbacks use irqsave
spinlocks and do a bunch of MMIO, and rcu_read_lock is _real_ fast.

To stay as close as possible to the stop_machine semantics we first
update all the submit function pointers to the nop handler, then call
synchronize_rcu() to make sure no new requests can be submitted. This
should give us exactly the huge barrier we want.

I pondered whether we should annotate engine->submit_request as __rcu
and use rcu_assign_pointer and rcu_dereference on it. But the reason
behind those is to make sure the compiler/cpu barriers are there for
when you have an actual data structure you point at, to make sure all
the writes are seen correctly on the read side. But we just have a
function pointer, and .text isn't changed, so no need for these
barriers and hence no need for annotations.

Unfortunately there's a complication with the call to
intel_engine_init_global_seqno:

- Without stop_machine we must hold the corresponding spinlock.

- Without stop_machine we must ensure that all requests are marked as
  having failed with dma_fence_set_error() before we call it. That
  means we need to split the nop request submission into two phases,
  both synchronized with rcu:

  1. Only stop submitting the requests to hw and mark them as failed.

  2. After all pending requests in the scheduler/ring are suitably
  marked up as failed and we can force complete them all, also force
  complete by calling intel_engine_init_global_seqno().

This should fix the followwing lockdep splat:

======================================================
WARNING: possible circular locking dependency detected
4.14.0-rc3-CI-CI_DRM_3179+ rib#1 Tainted: G     U
------------------------------------------------------
kworker/3:4/562 is trying to acquire lock:
 (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffff8113d4bc>] stop_machine+0x1c/0x40

but task is already holding lock:
 (&dev->struct_mutex){+.+.}, at: [<ffffffffa0136588>] i915_reset_device+0x1e8/0x260 [i915]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> rib#6 (&dev->struct_mutex){+.+.}:
       __lock_acquire+0x1420/0x15e0
       lock_acquire+0xb0/0x200
       __mutex_lock+0x86/0x9b0
       mutex_lock_interruptible_nested+0x1b/0x20
       i915_mutex_lock_interruptible+0x51/0x130 [i915]
       i915_gem_fault+0x209/0x650 [i915]
       __do_fault+0x1e/0x80
       __handle_mm_fault+0xa08/0xed0
       handle_mm_fault+0x156/0x300
       __do_page_fault+0x2c5/0x570
       do_page_fault+0x28/0x250
       page_fault+0x22/0x30

-> rib#5 (&mm->mmap_sem){++++}:
       __lock_acquire+0x1420/0x15e0
       lock_acquire+0xb0/0x200
       __might_fault+0x68/0x90
       _copy_to_user+0x23/0x70
       filldir+0xa5/0x120
       dcache_readdir+0xf9/0x170
       iterate_dir+0x69/0x1a0
       SyS_getdents+0xa5/0x140
       entry_SYSCALL_64_fastpath+0x1c/0xb1

-> rib#4 (&sb->s_type->i_mutex_key#5){++++}:
       down_write+0x3b/0x70
       handle_create+0xcb/0x1e0
       devtmpfsd+0x139/0x180
       kthread+0x152/0x190
       ret_from_fork+0x27/0x40

-> rib#3 ((complete)&req.done){+.+.}:
       __lock_acquire+0x1420/0x15e0
       lock_acquire+0xb0/0x200
       wait_for_common+0x58/0x210
       wait_for_completion+0x1d/0x20
       devtmpfs_create_node+0x13d/0x160
       device_add+0x5eb/0x620
       device_create_groups_vargs+0xe0/0xf0
       device_create+0x3a/0x40
       msr_device_create+0x2b/0x40
       cpuhp_invoke_callback+0xc9/0xbf0
       cpuhp_thread_fun+0x17b/0x240
       smpboot_thread_fn+0x18a/0x280
       kthread+0x152/0x190
       ret_from_fork+0x27/0x40

-> rib#2 (cpuhp_state-up){+.+.}:
       __lock_acquire+0x1420/0x15e0
       lock_acquire+0xb0/0x200
       cpuhp_issue_call+0x133/0x1c0
       __cpuhp_setup_state_cpuslocked+0x139/0x2a0
       __cpuhp_setup_state+0x46/0x60
       page_writeback_init+0x43/0x67
       pagecache_init+0x3d/0x42
       start_kernel+0x3a8/0x3fc
       x86_64_start_reservations+0x2a/0x2c
       x86_64_start_kernel+0x6d/0x70
       verify_cpu+0x0/0xfb

-> rib#1 (cpuhp_state_mutex){+.+.}:
       __lock_acquire+0x1420/0x15e0
       lock_acquire+0xb0/0x200
       __mutex_lock+0x86/0x9b0
       mutex_lock_nested+0x1b/0x20
       __cpuhp_setup_state_cpuslocked+0x53/0x2a0
       __cpuhp_setup_state+0x46/0x60
       page_alloc_init+0x28/0x30
       start_kernel+0x145/0x3fc
       x86_64_start_reservations+0x2a/0x2c
       x86_64_start_kernel+0x6d/0x70
       verify_cpu+0x0/0xfb

-> #0 (cpu_hotplug_lock.rw_sem){++++}:
       check_prev_add+0x430/0x840
       __lock_acquire+0x1420/0x15e0
       lock_acquire+0xb0/0x200
       cpus_read_lock+0x3d/0xb0
       stop_machine+0x1c/0x40
       i915_gem_set_wedged+0x1a/0x20 [i915]
       i915_reset+0xb9/0x230 [i915]
       i915_reset_device+0x1f6/0x260 [i915]
       i915_handle_error+0x2d8/0x430 [i915]
       hangcheck_declare_hang+0xd3/0xf0 [i915]
       i915_hangcheck_elapsed+0x262/0x2d0 [i915]
       process_one_work+0x233/0x660
       worker_thread+0x4e/0x3b0
       kthread+0x152/0x190
       ret_from_fork+0x27/0x40

other info that might help us debug this:

Chain exists of:
  cpu_hotplug_lock.rw_sem --> &mm->mmap_sem --> &dev->struct_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&dev->struct_mutex);
                               lock(&mm->mmap_sem);
                               lock(&dev->struct_mutex);
  lock(cpu_hotplug_lock.rw_sem);

 *** DEADLOCK ***

3 locks held by kworker/3:4/562:
 #0:  ("events_long"){+.+.}, at: [<ffffffff8109c64a>] process_one_work+0x1aa/0x660
 rib#1:  ((&(&i915->gpu_error.hangcheck_work)->work)){+.+.}, at: [<ffffffff8109c64a>] process_one_work+0x1aa/0x660
 rib#2:  (&dev->struct_mutex){+.+.}, at: [<ffffffffa0136588>] i915_reset_device+0x1e8/0x260 [i915]

stack backtrace:
CPU: 3 PID: 562 Comm: kworker/3:4 Tainted: G     U          4.14.0-rc3-CI-CI_DRM_3179+ rib#1
Hardware name:                  /NUC7i5BNB, BIOS BNKBL357.86A.0048.2017.0704.1415 07/04/2017
Workqueue: events_long i915_hangcheck_elapsed [i915]
Call Trace:
 dump_stack+0x68/0x9f
 print_circular_bug+0x235/0x3c0
 ? lockdep_init_map_crosslock+0x20/0x20
 check_prev_add+0x430/0x840
 ? irq_work_queue+0x86/0xe0
 ? wake_up_klogd+0x53/0x70
 __lock_acquire+0x1420/0x15e0
 ? __lock_acquire+0x1420/0x15e0
 ? lockdep_init_map_crosslock+0x20/0x20
 lock_acquire+0xb0/0x200
 ? stop_machine+0x1c/0x40
 ? i915_gem_object_truncate+0x50/0x50 [i915]
 cpus_read_lock+0x3d/0xb0
 ? stop_machine+0x1c/0x40
 stop_machine+0x1c/0x40
 i915_gem_set_wedged+0x1a/0x20 [i915]
 i915_reset+0xb9/0x230 [i915]
 i915_reset_device+0x1f6/0x260 [i915]
 ? gen8_gt_irq_ack+0x170/0x170 [i915]
 ? work_on_cpu_safe+0x60/0x60
 i915_handle_error+0x2d8/0x430 [i915]
 ? vsnprintf+0xd1/0x4b0
 ? scnprintf+0x3a/0x70
 hangcheck_declare_hang+0xd3/0xf0 [i915]
 ? intel_runtime_pm_put+0x56/0xa0 [i915]
 i915_hangcheck_elapsed+0x262/0x2d0 [i915]
 process_one_work+0x233/0x660
 worker_thread+0x4e/0x3b0
 kthread+0x152/0x190
 ? process_one_work+0x660/0x660
 ? kthread_create_on_node+0x40/0x40
 ret_from_fork+0x27/0x40
Setting dangerous option reset - tainting kernel
i915 0000:00:02.0: Resetting chip after gpu hang
Setting dangerous option reset - tainting kernel
i915 0000:00:02.0: Resetting chip after gpu hang

v2: Have 1 global synchronize_rcu() barrier across all engines, and
improve commit message.

v3: We need to protect the seqno update with the timeline spinlock (in
set_wedged) to avoid racing with other updates of the seqno, like we
already do in nop_submit_request (Chris).

v4: Use two-phase sequence to plug the race Chris spotted where we can
complete requests before they're marked up with -EIO.

v5: Review from Chris:
- simplify nop_submit_request.
- Add comment to rcu_read_lock section.
- Align comments with the new style.

v6: Remove unused variable to appease CI.

Reviewed-by: Chris Wilson <[email protected]>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102886
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103096
Cc: Chris Wilson <[email protected]>
Cc: Mika Kuoppala <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Marta Lofstedt <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
djdeath pushed a commit to djdeath/linux that referenced this issue Dec 14, 2017
This gets rid of the following lockdep splat:

======================================================
WARNING: possible circular locking dependency detected
4.15.0-rc2-CI-Patchwork_7428+ rib#1 Not tainted
------------------------------------------------------
debugfs_test/1351 is trying to acquire lock:
 (&dev->struct_mutex){+.+.}, at: [<000000009d90d1a3>] i915_mutex_lock_interruptible+0x47/0x130 [i915]

but task is already holding lock:
 (&mm->mmap_sem){++++}, at: [<000000005df01c1e>] __do_page_fault+0x106/0x560

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> rib#6 (&mm->mmap_sem){++++}:
       __might_fault+0x63/0x90
       _copy_to_user+0x1e/0x70
       filldir+0x8c/0xf0
       dcache_readdir+0xeb/0x160
       iterate_dir+0xe6/0x150
       SyS_getdents+0xa0/0x130
       entry_SYSCALL_64_fastpath+0x1c/0x89

-> rib#5 (&sb->s_type->i_mutex_key#5){++++}:
       lockref_get+0x9/0x20

-> rib#4 ((completion)&req.done){+.+.}:
       wait_for_common+0x54/0x210
       devtmpfs_create_node+0x130/0x150
       device_add+0x5ad/0x5e0
       device_create_groups_vargs+0xd4/0xe0
       device_create+0x35/0x40
       msr_device_create+0x22/0x40
       cpuhp_invoke_callback+0xc5/0xbf0
       cpuhp_thread_fun+0x167/0x210
       smpboot_thread_fn+0x17f/0x270
       kthread+0x173/0x1b0
       ret_from_fork+0x24/0x30

-> rib#3 (cpuhp_state-up){+.+.}:
       cpuhp_issue_call+0x132/0x1c0
       __cpuhp_setup_state_cpuslocked+0x12f/0x2a0
       __cpuhp_setup_state+0x3a/0x50
       page_writeback_init+0x3a/0x5c
       start_kernel+0x393/0x3e2
       secondary_startup_64+0xa5/0xb0

-> rib#2 (cpuhp_state_mutex){+.+.}:
       __mutex_lock+0x81/0x9b0
       __cpuhp_setup_state_cpuslocked+0x4b/0x2a0
       __cpuhp_setup_state+0x3a/0x50
       page_alloc_init+0x1f/0x26
       start_kernel+0x139/0x3e2
       secondary_startup_64+0xa5/0xb0

-> rib#1 (cpu_hotplug_lock.rw_sem){++++}:
       cpus_read_lock+0x34/0xa0
       apply_workqueue_attrs+0xd/0x40
       __alloc_workqueue_key+0x2c7/0x4e1
       intel_guc_submission_init+0x10c/0x650 [i915]
       intel_uc_init_hw+0x29e/0x460 [i915]
       i915_gem_init_hw+0xca/0x290 [i915]
       i915_gem_init+0x115/0x3a0 [i915]
       i915_driver_load+0x9a8/0x16c0 [i915]
       i915_pci_probe+0x2e/0x90 [i915]
       pci_device_probe+0x9c/0x120
       driver_probe_device+0x2a3/0x480
       __driver_attach+0xd9/0xe0
       bus_for_each_dev+0x57/0x90
       bus_add_driver+0x168/0x260
       driver_register+0x52/0xc0
       do_one_initcall+0x39/0x150
       do_init_module+0x56/0x1ef
       load_module+0x231c/0x2d70
       SyS_finit_module+0xa5/0xe0
       entry_SYSCALL_64_fastpath+0x1c/0x89

-> #0 (&dev->struct_mutex){+.+.}:
       lock_acquire+0xaf/0x200
       __mutex_lock+0x81/0x9b0
       i915_mutex_lock_interruptible+0x47/0x130 [i915]
       i915_gem_fault+0x201/0x760 [i915]
       __do_fault+0x15/0x70
       __handle_mm_fault+0x85b/0xe40
       handle_mm_fault+0x14f/0x2f0
       __do_page_fault+0x2d1/0x560
       page_fault+0x22/0x30

other info that might help us debug this:

Chain exists of:
  &dev->struct_mutex --> &sb->s_type->i_mutex_key#5 --> &mm->mmap_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&mm->mmap_sem);
                               lock(&sb->s_type->i_mutex_key#5);
                               lock(&mm->mmap_sem);
  lock(&dev->struct_mutex);

 *** DEADLOCK ***

1 lock held by debugfs_test/1351:
 #0:  (&mm->mmap_sem){++++}, at: [<000000005df01c1e>] __do_page_fault+0x106/0x560

stack backtrace:
CPU: 2 PID: 1351 Comm: debugfs_test Not tainted 4.15.0-rc2-CI-Patchwork_7428+ rib#1
Hardware name:                  /NUC6i5SYB, BIOS SYSKLi35.86A.0057.2017.0119.1758 01/19/2017
Call Trace:
 dump_stack+0x5f/0x86
 print_circular_bug+0x230/0x3b0
 check_prev_add+0x439/0x7b0
 ? lockdep_init_map_crosslock+0x20/0x20
 ? unwind_get_return_address+0x16/0x30
 ? __lock_acquire+0x1385/0x15a0
 __lock_acquire+0x1385/0x15a0
 lock_acquire+0xaf/0x200
 ? i915_mutex_lock_interruptible+0x47/0x130 [i915]
 __mutex_lock+0x81/0x9b0
 ? i915_mutex_lock_interruptible+0x47/0x130 [i915]
 ? i915_mutex_lock_interruptible+0x47/0x130 [i915]
 ? i915_mutex_lock_interruptible+0x47/0x130 [i915]
 i915_mutex_lock_interruptible+0x47/0x130 [i915]
 ? __pm_runtime_resume+0x4f/0x80
 i915_gem_fault+0x201/0x760 [i915]
 __do_fault+0x15/0x70
 __handle_mm_fault+0x85b/0xe40
 handle_mm_fault+0x14f/0x2f0
 __do_page_fault+0x2d1/0x560
 page_fault+0x22/0x30
RIP: 0033:0x7f98d6f49116
RSP: 002b:00007ffd6ffc3278 EFLAGS: 00010283
RAX: 00007f98d39a2bc0 RBX: 0000000000000000 RCX: 0000000000001680
RDX: 0000000000001680 RSI: 00007ffd6ffc3400 RDI: 00007f98d39a2bc0
RBP: 00007ffd6ffc33a0 R08: 0000000000000000 R09: 00000000000005a0
R10: 000055e847c2a830 R11: 0000000000000002 R12: 0000000000000001
R13: 000055e847c1d040 R14: 00007ffd6ffc3400 R15: 00007f98d6752ba0

v2: Init preempt_work unconditionally (Chris)
v3: Mention that we need the enable_guc=1 for lockdep splat (Chris)

Testcase: igt/debugfs_test/read_all_entries # with i915.enable_guc=1
Signed-off-by: Michał Winiarski <[email protected]>
Cc: Chris Wilson <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Cc: Michal Wajdeczko <[email protected]>
Reviewed-by: Chris Wilson <[email protected]>
Signed-off-by: Chris Wilson <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
djdeath pushed a commit to djdeath/linux that referenced this issue Jan 11, 2018
Calling tipc_mon_delete() before the monitor has been created will oops.
This can happen in tipc_enable_bearer() error path if tipc_disc_create()
fails.

[   48.589074] BUG: unable to handle kernel paging request at 0000000000001008
[   48.590266] IP: tipc_mon_delete+0xea/0x270 [tipc]
[   48.591223] PGD 1e60c5067 P4D 1e60c5067 PUD 1eb0cf067 PMD 0
[   48.592230] Oops: 0000 [rib#1] SMP KASAN
[   48.595610] CPU: 5 PID: 1199 Comm: tipc Tainted: G    B            4.15.0-rc4-pc64-dirty rib#5
[   48.597176] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014
[   48.598489] RIP: 0010:tipc_mon_delete+0xea/0x270 [tipc]
[   48.599347] RSP: 0018:ffff8801d827f668 EFLAGS: 00010282
[   48.600705] RAX: ffff8801ee813f00 RBX: 0000000000000204 RCX: 0000000000000000
[   48.602183] RDX: 1ffffffff1de6a75 RSI: 0000000000000297 RDI: 0000000000000297
[   48.604373] RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff1dd1533
[   48.605607] R10: ffffffff8eafbb05 R11: fffffbfff1dd1534 R12: 0000000000000050
[   48.607082] R13: dead000000000200 R14: ffffffff8e73f310 R15: 0000000000001020
[   48.608228] FS:  00007fc686484800(0000) GS:ffff8801f5540000(0000) knlGS:0000000000000000
[   48.610189] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   48.611459] CR2: 0000000000001008 CR3: 00000001dda70002 CR4: 00000000003606e0
[   48.612759] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   48.613831] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   48.615038] Call Trace:
[   48.615635]  tipc_enable_bearer+0x415/0x5e0 [tipc]
[   48.620623]  tipc_nl_bearer_enable+0x1ab/0x200 [tipc]
[   48.625118]  genl_family_rcv_msg+0x36b/0x570
[   48.631233]  genl_rcv_msg+0x5a/0xa0
[   48.631867]  netlink_rcv_skb+0x1cc/0x220
[   48.636373]  genl_rcv+0x24/0x40
[   48.637306]  netlink_unicast+0x29c/0x350
[   48.639664]  netlink_sendmsg+0x439/0x590
[   48.642014]  SYSC_sendto+0x199/0x250
[   48.649912]  do_syscall_64+0xfd/0x2c0
[   48.650651]  entry_SYSCALL64_slow_path+0x25/0x25
[   48.651843] RIP: 0033:0x7fc6859848e3
[   48.652539] RSP: 002b:00007ffd25dff938 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[   48.654003] RAX: ffffffffffffffda RBX: 00007ffd25dff990 RCX: 00007fc6859848e3
[   48.655303] RDX: 0000000000000054 RSI: 00007ffd25dff990 RDI: 0000000000000003
[   48.656512] RBP: 00007ffd25dff980 R08: 00007fc685c35fc0 R09: 000000000000000c
[   48.657697] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000d13010
[   48.658840] R13: 00007ffd25e009c0 R14: 0000000000000000 R15: 0000000000000000
[   48.662972] RIP: tipc_mon_delete+0xea/0x270 [tipc] RSP: ffff8801d827f668
[   48.664073] CR2: 0000000000001008
[   48.664576] ---[ end trace e811818d54d5ce88 ]---

Acked-by: Ying Xue <[email protected]>
Acked-by: Jon Maloy <[email protected]>
Signed-off-by: Tommi Rantala <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Jan 26, 2018
While working on fixing another bug, I ran into the following panic
on arm64 by simply attaching clsact qdisc, adding a filter and running
traffic on ingress to it:

  [...]
  [  178.188591] Unable to handle kernel read from unreadable memory at virtual address 810fb501f000
  [  178.197314] Mem abort info:
  [  178.200121]   ESR = 0x96000004
  [  178.203168]   Exception class = DABT (current EL), IL = 32 bits
  [  178.209095]   SET = 0, FnV = 0
  [  178.212157]   EA = 0, S1PTW = 0
  [  178.215288] Data abort info:
  [  178.218175]   ISV = 0, ISS = 0x00000004
  [  178.222019]   CM = 0, WnR = 0
  [  178.224997] user pgtable: 4k pages, 48-bit VAs, pgd = 0000000023cb3f33
  [  178.231531] [0000810fb501f000] *pgd=0000000000000000
  [  178.236508] Internal error: Oops: 96000004 [rib#1] SMP
  [...]
  [  178.311855] CPU: 73 PID: 2497 Comm: ping Tainted: G        W        4.15.0-rc7+ rib#5
  [  178.319413] Hardware name: FOXCONN R2-1221R-A4/C2U4N_MB, BIOS G31FB18A 03/31/2017
  [  178.326887] pstate: 60400005 (nZCv daif +PAN -UAO)
  [  178.331685] pc : __netif_receive_skb_core+0x49c/0xac8
  [  178.336728] lr : __netif_receive_skb+0x28/0x78
  [  178.341161] sp : ffff00002344b750
  [  178.344465] x29: ffff00002344b750 x28: ffff810fbdfd0580
  [  178.349769] x27: 0000000000000000 x26: ffff000009378000
  [...]
  [  178.418715] x1 : 0000000000000054 x0 : 0000000000000000
  [  178.424020] Process ping (pid: 2497, stack limit = 0x000000009f0a3ff4)
  [  178.430537] Call trace:
  [  178.432976]  __netif_receive_skb_core+0x49c/0xac8
  [  178.437670]  __netif_receive_skb+0x28/0x78
  [  178.441757]  process_backlog+0x9c/0x160
  [  178.445584]  net_rx_action+0x2f8/0x3f0
  [...]

Reason is that sch_ingress and sch_clsact are doing mini_qdisc_pair_init()
which sets up miniq pointers to cpu_{b,q}stats from the underlying qdisc.
Problem is that this cannot work since they are actually set up right after
the qdisc ->init() callback in qdisc_create(), so first packet going into
sch_handle_ingress() tries to call mini_qdisc_bstats_cpu_update() and we
therefore panic.

In order to fix this, allocation of {b,q}stats needs to happen before we
call into ->init(). In net-next, there's already such option through commit
d59f5ff ("net: sched: a dflt qdisc may be used with per cpu stats").
However, the bug needs to be fixed in net still for 4.15. Thus, include
these bits to reduce any merge churn and reuse the static_flags field to
set TCQ_F_CPUSTATS, and remove the allocation from qdisc_create() since
there is no other user left. Prashant Bhole ran into the same issue but
for net-next, thus adding him below as well as co-author. Same issue was
also reported by Sandipan Das when using bcc.

Fixes: 4620940 ("net: core: introduce mini_Qdisc and eliminate usage of tp->q for clsact fastpath")
Reference: https://lists.iovisor.org/pipermail/iovisor-dev/2018-January/001190.html
Reported-by: Sandipan Das <[email protected]>
Co-authored-by: Prashant Bhole <[email protected]>
Co-authored-by: John Fastabend <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Cc: Jiri Pirko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Jan 29, 2018
Lockdep gifted us with noticing the following 4-way lockup scenario:

        perf_trace_init()
 #0       mutex_lock(&event_mutex)
          perf_trace_event_init()
            perf_trace_event_reg()
              tp_event->class->reg() := tracepoint_probe_register
 rib#1             mutex_lock(&tracepoints_mutex)
                  trace_point_add_func()
 rib#2                 static_key_enable()

 rib#2     do_cpu_up()
          perf_event_init_cpu()
 rib#3         mutex_lock(&pmus_lock)
 rib#4         mutex_lock(&ctx->mutex)

        perf_event_task_disable()
          mutex_lock(&current->perf_event_mutex)
 rib#4       ctx = perf_event_ctx_lock()
 rib#5       perf_event_for_each_child()

        do_exit()
          task_work_run()
            __fput()
              perf_release()
                perf_event_release_kernel()
 rib#4               mutex_lock(&ctx->mutex)
 rib#5               mutex_lock(&event->child_mutex)
                  free_event()
                    _free_event()
                      event->destroy() := perf_trace_destroy
 #0                     mutex_lock(&event_mutex);

Fix that by moving the free_event() out from under the locks.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vince Weaver <[email protected]>
Cc: [email protected]
Signed-off-by: Ingo Molnar <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Mar 1, 2018
It was reported by Sergey Senozhatsky that if THP (Transparent Huge
Page) and frontswap (via zswap) are both enabled, when memory goes low
so that swap is triggered, segfault and memory corruption will occur in
random user space applications as follow,

kernel: urxvt[338]: segfault at 20 ip 00007fc08889ae0d sp 00007ffc73a7fc40 error 6 in libc-2.26.so[7fc08881a000+1ae000]
 #0  0x00007fc08889ae0d _int_malloc (libc.so.6)
 rib#1  0x00007fc08889c2f3 malloc (libc.so.6)
 rib#2  0x0000560e6004bff7 _Z14rxvt_wcstoutf8PKwi (urxvt)
 rib#3  0x0000560e6005e75c n/a (urxvt)
 rib#4  0x0000560e6007d9f1 _ZN16rxvt_perl_interp6invokeEP9rxvt_term9hook_typez (urxvt)
 rib#5  0x0000560e6003d988 _ZN9rxvt_term9cmd_parseEv (urxvt)
 rib#6  0x0000560e60042804 _ZN9rxvt_term6pty_cbERN2ev2ioEi (urxvt)
 rib#7  0x0000560e6005c10f _Z17ev_invoke_pendingv (urxvt)
 rib#8  0x0000560e6005cb55 ev_run (urxvt)
 rib#9  0x0000560e6003b9b9 main (urxvt)
 rib#10 0x00007fc08883af4a __libc_start_main (libc.so.6)
 rib#11 0x0000560e6003f9da _start (urxvt)

After bisection, it was found the first bad commit is bd4c82c ("mm,
THP, swap: delay splitting THP after swapped out").

The root cause is as follows:

When the pages are written to swap device during swapping out in
swap_writepage(), zswap (fontswap) is tried to compress the pages to
improve performance.  But zswap (frontswap) will treat THP as a normal
page, so only the head page is saved.  After swapping in, tail pages
will not be restored to their original contents, causing memory
corruption in the applications.

This is fixed by refusing to save page in the frontswap store functions
if the page is a THP.  So that the THP will be swapped out to swap
device.

Another choice is to split THP if frontswap is enabled.  But it is found
that the frontswap enabling isn't flexible.  For example, if
CONFIG_ZSWAP=y (cannot be module), frontswap will be enabled even if
zswap itself isn't enabled.

Frontswap has multiple backends, to make it easy for one backend to
enable THP support, the THP checking is put in backend frontswap store
functions instead of the general interfaces.

Link: http://lkml.kernel.org/r/[email protected]
Fixes: bd4c82c ("mm, THP, swap: delay splitting THP after swapped out")
Signed-off-by: "Huang, Ying" <[email protected]>
Reported-by: Sergey Senozhatsky <[email protected]>
Tested-by: Sergey Senozhatsky <[email protected]>
Suggested-by: Minchan Kim <[email protected]>	[put THP checking in backend]
Cc: Konrad Rzeszutek Wilk <[email protected]>
Cc: Dan Streetman <[email protected]>
Cc: Seth Jennings <[email protected]>
Cc: Tetsuo Handa <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: <[email protected]>	[4.14]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Mar 13, 2018
Currently we can crash perf record when running in pipe mode, like:

  $ perf record ls | perf report
  # To display the perf.data header info, please use --header/--header-only options.
  #
  perf: Segmentation fault
  Error:
  The - file has no samples!

The callstack of the crash is:

    0x0000000000515242 in perf_event__synthesize_event_update_name
  3513            ev = event_update_event__new(len + 1, PERF_EVENT_UPDATE__NAME, evsel->id[0]);
  (gdb) bt
  #0  0x0000000000515242 in perf_event__synthesize_event_update_name
  rib#1  0x00000000005158a4 in perf_event__synthesize_extra_attr
  rib#2  0x0000000000443347 in record__synthesize
  rib#3  0x00000000004438e3 in __cmd_record
  rib#4  0x000000000044514e in cmd_record
  rib#5  0x00000000004cbc95 in run_builtin
  rib#6  0x00000000004cbf02 in handle_internal_command
  rib#7  0x00000000004cc054 in run_argv
  rib#8  0x00000000004cc422 in main

The reason of the crash is that the evsel does not have ids array
allocated and the pipe's synthesize code tries to access it.

We don't force evsel ids allocation when we have single event, because
it's not needed. However we need it when we are in pipe mode even for
single event as a key for evsel update event.

Fixing this by forcing evsel ids allocation event for single event, when
we are in pipe mode.

Signed-off-by: Jiri Olsa <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue May 22, 2018
stub_probe() calls put_busid_priv() in an error path when device isn't
found in the busid_table. Fix it by making put_busid_priv() safe to be
called with null struct bus_id_priv pointer.

This problem happens when "usbip bind" is run without loading usbip_host
driver and then running modprobe. The first failed bind attempt unbinds
the device from the original driver and when usbip_host is modprobed,
stub_probe() runs and doesn't find the device in its busid table and calls
put_busid_priv(0 with null bus_id_priv pointer.

usbip-host 3-10.2: 3-10.2 is not in match_busid table...  skip!

[  367.359679] =====================================
[  367.359681] WARNING: bad unlock balance detected!
[  367.359683] 4.17.0-rc4+ rib#5 Not tainted
[  367.359685] -------------------------------------
[  367.359688] modprobe/2768 is trying to release lock (
[  367.359689]
==================================================================
[  367.359696] BUG: KASAN: null-ptr-deref in print_unlock_imbalance_bug+0x99/0x110
[  367.359699] Read of size 8 at addr 0000000000000058 by task modprobe/2768

[  367.359705] CPU: 4 PID: 2768 Comm: modprobe Not tainted 4.17.0-rc4+ rib#5

Fixes: 2207655 ("usbip: usbip_host: fix NULL-ptr deref and use-after-free errors") in usb-linus
Signed-off-by: Shuah Khan (Samsung OSG) <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Oct 22, 2018
Fixes a crash when the report encounters an address that could not be
associated with an mmaped region:

  #0  0x00005555557bdc4a in callchain_srcline (ip=<error reading variable: Cannot access memory at address 0x38>, sym=0x0, map=0x0) at util/machine.c:2329
  rib#1  unwind_entry (entry=entry@entry=0x7fffffff9180, arg=arg@entry=0x7ffff5642498) at util/machine.c:2329
  rib#2  0x00005555558370af in entry (arg=0x7ffff5642498, cb=0x5555557bdb50 <unwind_entry>, thread=<optimized out>, ip=18446744073709551615) at util/unwind-libunwind-local.c:586
  rib#3  get_entries (ui=ui@entry=0x7fffffff9620, cb=0x5555557bdb50 <unwind_entry>, arg=0x7ffff5642498, max_stack=<optimized out>) at util/unwind-libunwind-local.c:703
  rib#4  0x0000555555837192 in _unwind__get_entries (cb=<optimized out>, arg=<optimized out>, thread=<optimized out>, data=<optimized out>, max_stack=<optimized out>) at util/unwind-libunwind-local.c:725
  rib#5  0x00005555557c310f in thread__resolve_callchain_unwind (max_stack=127, sample=0x7fffffff9830, evsel=0x555555c7b3b0, cursor=0x7ffff5642498, thread=0x555555c7f6f0) at util/machine.c:2351
  rib#6  thread__resolve_callchain (thread=0x555555c7f6f0, cursor=0x7ffff5642498, evsel=0x555555c7b3b0, sample=0x7fffffff9830, parent=0x7fffffff97b8, root_al=0x7fffffff9750, max_stack=127) at util/machine.c:2378
  rib#7  0x00005555557ba4ee in sample__resolve_callchain (sample=<optimized out>, cursor=<optimized out>, parent=parent@entry=0x7fffffff97b8, evsel=<optimized out>, al=al@entry=0x7fffffff9750,
      max_stack=<optimized out>) at util/callchain.c:1085

Signed-off-by: Milian Wolff <[email protected]>
Tested-by: Sandipan Das <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Jin Yao <[email protected]>
Cc: Namhyung Kim <[email protected]>
Fixes: 2a9d505 ("perf script: Show correct offsets for DWARF-based unwinding")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Oct 22, 2018
This reverts commit d76c743.

While commit d76c743 ("serial: 8250_dw: Fix runtime PM handling")
fixes runtime PM handling when using kgdb, it introduces a traceback for
everyone else.

BUG: sleeping function called from invalid context at
	/mnt/host/source/src/third_party/kernel/next/drivers/base/power/runtime.c:1034
in_atomic(): 1, irqs_disabled(): 1, pid: 1, name: swapper/0
7 locks held by swapper/0/1:
 #0: 000000005ec5bc72 (&dev->mutex){....}, at: __driver_attach+0xb5/0x12b
 rib#1: 000000005d5fa9e5 (&dev->mutex){....}, at: __device_attach+0x3e/0x15b
 rib#2: 0000000047e93286 (serial_mutex){+.+.}, at: serial8250_register_8250_port+0x51/0x8bb
 rib#3: 000000003b328f07 (port_mutex){+.+.}, at: uart_add_one_port+0xab/0x8b0
 rib#4: 00000000fa313d4d (&port->mutex){+.+.}, at: uart_add_one_port+0xcc/0x8b0
 rib#5: 00000000090983ca (console_lock){+.+.}, at: vprintk_emit+0xdb/0x217
 rib#6: 00000000c743e583 (console_owner){-...}, at: console_unlock+0x211/0x60f
irq event stamp: 735222
__down_trylock_console_sem+0x4a/0x84
console_unlock+0x338/0x60f
__do_softirq+0x4a4/0x50d
irq_exit+0x64/0xe2
CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc5 rib#6
Hardware name: Google Caroline/Caroline, BIOS Google_Caroline.7820.286.0 03/15/2017
Call Trace:
 dump_stack+0x7d/0xbd
 ___might_sleep+0x238/0x259
 __pm_runtime_resume+0x4e/0xa4
 ? serial8250_rpm_get+0x2e/0x44
 serial8250_console_write+0x44/0x301
 ? lock_acquire+0x1b8/0x1fa
 console_unlock+0x577/0x60f
 vprintk_emit+0x1f0/0x217
 printk+0x52/0x6e
 register_console+0x43b/0x524
 uart_add_one_port+0x672/0x8b0
 ? set_io_from_upio+0x150/0x162
 serial8250_register_8250_port+0x825/0x8bb
 dw8250_probe+0x80c/0x8b0
 ? dw8250_serial_inq+0x8e/0x8e
 ? dw8250_check_lcr+0x108/0x108
 ? dw8250_runtime_resume+0x5b/0x5b
 ? dw8250_serial_outq+0xa1/0xa1
 ? dw8250_remove+0x115/0x115
 platform_drv_probe+0x76/0xc5
 really_probe+0x1f1/0x3ee
 ? driver_allows_async_probing+0x5d/0x5d
 driver_probe_device+0xd6/0x112
 ? driver_allows_async_probing+0x5d/0x5d
 bus_for_each_drv+0xbe/0xe5
 __device_attach+0xdd/0x15b
 bus_probe_device+0x5a/0x10b
 device_add+0x501/0x894
 ? _raw_write_unlock+0x27/0x3a
 platform_device_add+0x224/0x2b7
 mfd_add_device+0x718/0x75b
 ? __kmalloc+0x144/0x16a
 ? mfd_add_devices+0x38/0xdb
 mfd_add_devices+0x9b/0xdb
 intel_lpss_probe+0x7d4/0x8ee
 intel_lpss_pci_probe+0xac/0xd4
 pci_device_probe+0x101/0x18e
...

Revert the offending patch until a more comprehensive solution
is available.

Cc: Tony Lindgren <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Phil Edworthy <[email protected]>
Fixes: d76c743 ("serial: 8250_dw: Fix runtime PM handling")
Signed-off-by: Guenter Roeck <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Feb 14, 2019
Song Liu reported crash in 'perf record':

  > #0  0x0000000000500055 in ordered_events(float, long double,...)(...) ()
  > rib#1  0x0000000000500196 in ordered_events.reinit ()
  > rib#2  0x00000000004fe413 in perf_session.process_events ()
  > rib#3  0x0000000000440431 in cmd_record ()
  > rib#4  0x00000000004a439f in run_builtin ()
  > rib#5  0x000000000042b3e5 in main ()"

This can happen when we get out of buffers during event processing.

The subsequent ordered_events__free() call assumes oe->buffer != NULL
and crashes. Add a check to prevent that.

Reported-by: Song Liu <[email protected]>
Signed-off-by: Jiri Olsa <[email protected]>
Reviewed-by: Song Liu <[email protected]>
Tested-by: Song Liu <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Fixes: d5ceb62 ("perf ordered_events: Add 'struct ordered_events_buffer' layer")
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Feb 14, 2019
Ido Schimmel says:

====================
mlxsw: Various fixes

This patchset contains small fixes in mlxsw and one fix in the bridge
driver.

Patches rib#1-rib#4 perform small adjustments in PCI and FID code following
recent tests that were performed on the Spectrum-2 ASIC.

Patch rib#5 fixes the bridge driver to mark FDB entries that were added by
user as such. Otherwise, these entries will be ignored by underlying
switch drivers.

Patch rib#6 fixes a long standing issue in mlxsw where the driver
incorrectly programmed static FDB entries as both static and sticky.

Patches rib#7-rib#8 add test cases for above mentioned bugs.

Please consider patches rib#1, rib#2 and rib#4 for stable.
====================

Signed-off-by: David S. Miller <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Feb 14, 2019
When option CONFIG_KASAN is enabled toghether with ftrace, function
ftrace_graph_caller() gets in to a recursion, via functions
kasan_check_read() and kasan_check_write().

 Breakpoint 2, ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179
 179             mcount_get_pc             x0    //     function's pc
 (gdb) bt
 #0  ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179
 rib#1  0xffffff90101406c8 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:151
 rib#2  0xffffff90106fd084 in kasan_check_write (p=0xffffffc06c170878, size=4) at ../mm/kasan/common.c:105
 rib#3  0xffffff90104a2464 in atomic_add_return (v=<optimized out>, i=<optimized out>) at ./include/generated/atomic-instrumented.h:71
 rib#4  atomic_inc_return (v=<optimized out>) at ./include/generated/atomic-fallback.h:284
 rib#5  trace_graph_entry (trace=0xffffffc03f5ff380) at ../kernel/trace/trace_functions_graph.c:441
 rib#6  0xffffff9010481774 in trace_graph_entry_watchdog (trace=<optimized out>) at ../kernel/trace/trace_selftest.c:741
 rib#7  0xffffff90104a185c in function_graph_enter (ret=<optimized out>, func=<optimized out>, frame_pointer=18446743799894897728, retp=<optimized out>) at ../kernel/trace/trace_functions_graph.c:196
 rib#8  0xffffff9010140628 in prepare_ftrace_return (self_addr=18446743592948977792, parent=0xffffffc03f5ff418, frame_pointer=18446743799894897728) at ../arch/arm64/kernel/ftrace.c:231
 rib#9  0xffffff90101406f4 in ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:182
 Backtrace stopped: previous frame identical to this frame (corrupt stack?)
 (gdb)

Rework so that the kasan implementation isn't traced.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Anders Roxell <[email protected]>
Acked-by: Dmitry Vyukov <[email protected]>
Tested-by: Dmitry Vyukov <[email protected]>
Acked-by: Steven Rostedt (VMware) <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Feb 18, 2019
KMSAN reported batadv_interface_tx() was possibly using a
garbage value [1]

batadv_get_vid() does have a pskb_may_pull() call
but batadv_interface_tx() does not actually make sure
this did not fail.

[1]
BUG: KMSAN: uninit-value in batadv_interface_tx+0x908/0x1e40 net/batman-adv/soft-interface.c:231
CPU: 0 PID: 10006 Comm: syz-executor469 Not tainted 4.20.0-rc7+ rib#5
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x173/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:613
 __msan_warning+0x82/0xf0 mm/kmsan/kmsan_instr.c:313
 batadv_interface_tx+0x908/0x1e40 net/batman-adv/soft-interface.c:231
 __netdev_start_xmit include/linux/netdevice.h:4356 [inline]
 netdev_start_xmit include/linux/netdevice.h:4365 [inline]
 xmit_one net/core/dev.c:3257 [inline]
 dev_hard_start_xmit+0x607/0xc40 net/core/dev.c:3273
 __dev_queue_xmit+0x2e42/0x3bc0 net/core/dev.c:3843
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3876
 packet_snd net/packet/af_packet.c:2928 [inline]
 packet_sendmsg+0x8306/0x8f30 net/packet/af_packet.c:2953
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 __sys_sendto+0x8c4/0xac0 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1796
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1796
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x441889
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 bb 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdda6fd468 EFLAGS: 00000216 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000441889
RDX: 000000000000000e RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000216 R12: 00007ffdda6fd4c0
R13: 00007ffdda6fd4b0 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:204 [inline]
 kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:158
 kmsan_kmalloc+0xa6/0x130 mm/kmsan/kmsan_hooks.c:176
 kmsan_slab_alloc+0xe/0x10 mm/kmsan/kmsan_hooks.c:185
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2759 [inline]
 __kmalloc_node_track_caller+0xe18/0x1030 mm/slub.c:4383
 __kmalloc_reserve net/core/skbuff.c:137 [inline]
 __alloc_skb+0x309/0xa20 net/core/skbuff.c:205
 alloc_skb include/linux/skbuff.h:998 [inline]
 alloc_skb_with_frags+0x1c7/0xac0 net/core/skbuff.c:5220
 sock_alloc_send_pskb+0xafd/0x10e0 net/core/sock.c:2083
 packet_alloc_skb net/packet/af_packet.c:2781 [inline]
 packet_snd net/packet/af_packet.c:2872 [inline]
 packet_sendmsg+0x661a/0x8f30 net/packet/af_packet.c:2953
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 __sys_sendto+0x8c4/0xac0 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1796
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1796
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Fixes: c6c8fea ("net: Add batman-adv meshing protocol")
Signed-off-by: Eric Dumazet <[email protected]>
Reported-by: syzbot <[email protected]>
Cc:	Marek Lindner <[email protected]>
Cc:	Simon Wunderlich <[email protected]>
Cc:	Antonio Quartulli <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Mar 29, 2019
…_map

Detected via gcc's ASan:

  Direct leak of 2048 byte(s) in 64 object(s) allocated from:
    6     #0 0x7f606512e370 in __interceptor_realloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee370)
    7     rib#1 0x556b0f1d7ddd in thread_map__realloc util/thread_map.c:43
    8     rib#2 0x556b0f1d84c7 in thread_map__new_by_tid util/thread_map.c:85
    9     rib#3 0x556b0f0e045e in is_event_supported util/parse-events.c:2250
   10     rib#4 0x556b0f0e1aa1 in print_hwcache_events util/parse-events.c:2382
   11     rib#5 0x556b0f0e3231 in print_events util/parse-events.c:2514
   12     rib#6 0x556b0ee0a66e in cmd_list /home/changbin/work/linux/tools/perf/builtin-list.c:58
   13     rib#7 0x556b0f01e0ae in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
   14     rib#8 0x556b0f01e859 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
   15     rib#9 0x556b0f01edc8 in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
   16     rib#10 0x556b0f01f71f in main /home/changbin/work/linux/tools/perf/perf.c:520
   17     rib#11 0x7f6062ccf09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Fixes: 8989605 ("perf tools: Do not put a variable sized type not at the end of a struct")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Mar 29, 2019
Detected with gcc's ASan:

  Direct leak of 66 byte(s) in 5 object(s) allocated from:
      #0 0x7ff3b1f32070 in __interceptor_strdup (/usr/lib/x86_64-linux-gnu/libasan.so.5+0x3b070)
      rib#1 0x560c8761034d in collect_config util/config.c:597
      rib#2 0x560c8760d9cb in get_value util/config.c:169
      rib#3 0x560c8760dfd7 in perf_parse_file util/config.c:285
      rib#4 0x560c8760e0d2 in perf_config_from_file util/config.c:476
      rib#5 0x560c876108fd in perf_config_set__init util/config.c:661
      rib#6 0x560c87610c72 in perf_config_set__new util/config.c:709
      rib#7 0x560c87610d2f in perf_config__init util/config.c:718
      rib#8 0x560c87610e5d in perf_config util/config.c:730
      rib#9 0x560c875ddea0 in main /home/changbin/work/linux/tools/perf/perf.c:442
      rib#10 0x7ff3afb8609a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Cc: Taeung Song <[email protected]>
Fixes: 20105ca ("perf config: Introduce perf_config_set class")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Mar 29, 2019
Detected with gcc's ASan:

  Direct leak of 4356 byte(s) in 120 object(s) allocated from:
      #0 0x7ff1a2b5a070 in __interceptor_strdup (/usr/lib/x86_64-linux-gnu/libasan.so.5+0x3b070)
      rib#1 0x55719aef4814 in build_id_cache__origname util/build-id.c:215
      rib#2 0x55719af649b6 in print_sdt_events util/parse-events.c:2339
      rib#3 0x55719af66272 in print_events util/parse-events.c:2542
      rib#4 0x55719ad1ecaa in cmd_list /home/changbin/work/linux/tools/perf/builtin-list.c:58
      rib#5 0x55719aec745d in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      rib#6 0x55719aec7d1a in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      rib#7 0x55719aec8184 in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      rib#8 0x55719aeca41a in main /home/changbin/work/linux/tools/perf/perf.c:520
      rib#9 0x7ff1a07ae09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Fixes: 40218da ("perf list: Show SDT and pre-cached events")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Mar 29, 2019
…r-free issue

The evlist should be destroyed before the perf session.

Detected with gcc's ASan:

  =================================================================
  ==27350==ERROR: AddressSanitizer: heap-use-after-free on address 0x62b000002e38 at pc 0x5611da276999 bp 0x7ffce8f1d1a0 sp 0x7ffce8f1d190
  WRITE of size 8 at 0x62b000002e38 thread T0
      #0 0x5611da276998 in __list_del /home/work/linux/tools/include/linux/list.h:89
      rib#1 0x5611da276d4a in __list_del_entry /home/work/linux/tools/include/linux/list.h:102
      rib#2 0x5611da276e77 in list_del_init /home/work/linux/tools/include/linux/list.h:145
      rib#3 0x5611da2781cd in thread__put util/thread.c:130
      rib#4 0x5611da2cc0a8 in __thread__zput util/thread.h:68
      rib#5 0x5611da2d2dcb in hist_entry__delete util/hist.c:1148
      rib#6 0x5611da2cdf91 in hists__delete_entry util/hist.c:337
      rib#7 0x5611da2ce19e in hists__delete_entries util/hist.c:365
      rib#8 0x5611da2db2ab in hists__delete_all_entries util/hist.c:2639
      rib#9 0x5611da2db325 in hists_evsel__exit util/hist.c:2651
      rib#10 0x5611da1c5352 in perf_evsel__exit util/evsel.c:1304
      rib#11 0x5611da1c5390 in perf_evsel__delete util/evsel.c:1309
      rib#12 0x5611da1b35f0 in perf_evlist__purge util/evlist.c:124
      rib#13 0x5611da1b38e2 in perf_evlist__delete util/evlist.c:148
      rib#14 0x5611da069781 in cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1645
      rib#15 0x5611da17d038 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      rib#16 0x5611da17d577 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      rib#17 0x5611da17d97b in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      rib#18 0x5611da17e0e9 in main /home/changbin/work/linux/tools/perf/perf.c:520
      rib#19 0x7fdcc970f09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)
      rib#20 0x5611d9ff35c9 in _start (/home/work/linux/tools/perf/perf+0x3e95c9)

  0x62b000002e38 is located 11320 bytes inside of 27448-byte region [0x62b000000200,0x62b000006d38)
  freed by thread T0 here:
      #0 0x7fdccb04ab70 in free (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedb70)
      rib#1 0x5611da260df4 in perf_session__delete util/session.c:201
      rib#2 0x5611da063de5 in __cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1300
      rib#3 0x5611da06973c in cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1642
      rib#4 0x5611da17d038 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      rib#5 0x5611da17d577 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      rib#6 0x5611da17d97b in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      rib#7 0x5611da17e0e9 in main /home/changbin/work/linux/tools/perf/perf.c:520
      rib#8 0x7fdcc970f09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  previously allocated by thread T0 here:
      #0 0x7fdccb04b138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      rib#1 0x5611da26010c in zalloc util/util.h:23
      rib#2 0x5611da260824 in perf_session__new util/session.c:118
      rib#3 0x5611da0633a6 in __cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1192
      rib#4 0x5611da06973c in cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1642
      rib#5 0x5611da17d038 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      rib#6 0x5611da17d577 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      rib#7 0x5611da17d97b in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      rib#8 0x5611da17e0e9 in main /home/changbin/work/linux/tools/perf/perf.c:520
      rib#9 0x7fdcc970f09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  SUMMARY: AddressSanitizer: heap-use-after-free /home/work/linux/tools/include/linux/list.h:89 in __list_del
  Shadow bytes around the buggy address:
    0x0c567fff8570: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8580: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8590: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85a0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85b0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  =>0x0c567fff85c0: fd fd fd fd fd fd fd[fd]fd fd fd fd fd fd fd fd
    0x0c567fff85d0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85e0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85f0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8600: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8610: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  Shadow byte legend (one shadow byte represents 8 application bytes):
    Addressable:           00
    Partially addressable: 01 02 03 04 05 06 07
    Heap left redzone:       fa
    Freed heap region:       fd
    Stack left redzone:      f1
    Stack mid redzone:       f2
    Stack right redzone:     f3
    Stack after return:      f5
    Stack use after scope:   f8
    Global redzone:          f9
    Global init order:       f6
    Poisoned by user:        f7
    Container overflow:      fc
    Array cookie:            ac
    Intra object redzone:    bb
    ASan internal:           fe
    Left alloca redzone:     ca
    Right alloca redzone:    cb
  ==27350==ABORTING

Signed-off-by: Changbin Du <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Mar 29, 2019
The array str[] should have six elements.

  =================================================================
  ==4322==ERROR: AddressSanitizer: global-buffer-overflow on address 0x56463844e300 at pc 0x564637e7ad0d bp 0x7f30c8c89d10 sp 0x7f30c8c89d00
  READ of size 8 at 0x56463844e300 thread T9
      #0 0x564637e7ad0c in __ordered_events__flush util/ordered-events.c:316
      rib#1 0x564637e7b0e4 in ordered_events__flush util/ordered-events.c:338
      rib#2 0x564637c6a57d in process_thread /home/changbin/work/linux/tools/perf/builtin-top.c:1073
      rib#3 0x7f30d173a163 in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x8163)
      rib#4 0x7f30cfffbdee in __clone (/lib/x86_64-linux-gnu/libc.so.6+0x11adee)

  0x56463844e300 is located 32 bytes to the left of global variable 'flags' defined in 'util/trace-event-parse.c:229:26' (0x56463844e320) of size 192
  0x56463844e300 is located 0 bytes to the right of global variable 'str' defined in 'util/ordered-events.c:268:28' (0x56463844e2e0) of size 32
  SUMMARY: AddressSanitizer: global-buffer-overflow util/ordered-events.c:316 in __ordered_events__flush
  Shadow bytes around the buggy address:
    0x0ac947081c10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081c20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081c30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081c40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081c50: 00 00 00 00 00 00 00 00 f9 f9 f9 f9 00 00 00 00
  =>0x0ac947081c60:[f9]f9 f9 f9 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081c70: 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9 f9 f9
    0x0ac947081c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081c90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081ca0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081cb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  Shadow byte legend (one shadow byte represents 8 application bytes):
    Addressable:           00
    Partially addressable: 01 02 03 04 05 06 07
    Heap left redzone:       fa
    Freed heap region:       fd
    Stack left redzone:      f1
    Stack mid redzone:       f2
    Stack right redzone:     f3
    Stack after return:      f5
    Stack use after scope:   f8
    Global redzone:          f9
    Global init order:       f6
    Poisoned by user:        f7
    Container overflow:      fc
    Array cookie:            ac
    Intra object redzone:    bb
    ASan internal:           fe
    Left alloca redzone:     ca
    Right alloca redzone:    cb
  Thread T9 created by T0 here:
      #0 0x7f30d179de5f in __interceptor_pthread_create (/usr/lib/x86_64-linux-gnu/libasan.so.5+0x4ae5f)
      rib#1 0x564637c6b954 in __cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1253
      rib#2 0x564637c7173c in cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1642
      rib#3 0x564637d85038 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      rib#4 0x564637d85577 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      rib#5 0x564637d8597b in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      rib#6 0x564637d860e9 in main /home/changbin/work/linux/tools/perf/perf.c:520
      rib#7 0x7f30cff0509a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Cc: Jiri Olsa <[email protected]>
Fixes: 16c66bc ("perf top: Add processing thread")
Fixes: 68ca5d0 ("perf ordered_events: Add ordered_events__flush_time interface")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Mar 29, 2019
Using gcc's ASan, Changbin reports:

  =================================================================
  ==7494==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 48 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a89138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      rib#1 0x5625e5330a5e in zalloc util/util.h:23
      rib#2 0x5625e5330a9b in perf_counts__new util/counts.c:10
      rib#3 0x5625e5330ca0 in perf_evsel__alloc_counts util/counts.c:47
      rib#4 0x5625e520d8e5 in __perf_evsel__read_on_cpu util/evsel.c:1505
      rib#5 0x5625e517a985 in perf_evsel__read_on_cpu /home/work/linux/tools/perf/util/evsel.h:347
      rib#6 0x5625e517ad1a in test__openat_syscall_event tests/openat-syscall.c:47
      rib#7 0x5625e51528e6 in run_test tests/builtin-test.c:358
      rib#8 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      rib#9 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      rib#10 0x5625e515572f in cmd_test tests/builtin-test.c:722
      rib#11 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      rib#12 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      rib#13 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      rib#14 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      rib#15 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  Indirect leak of 72 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a89138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      rib#1 0x5625e532560d in zalloc util/util.h:23
      rib#2 0x5625e532566b in xyarray__new util/xyarray.c:10
      rib#3 0x5625e5330aba in perf_counts__new util/counts.c:15
      rib#4 0x5625e5330ca0 in perf_evsel__alloc_counts util/counts.c:47
      rib#5 0x5625e520d8e5 in __perf_evsel__read_on_cpu util/evsel.c:1505
      rib#6 0x5625e517a985 in perf_evsel__read_on_cpu /home/work/linux/tools/perf/util/evsel.h:347
      rib#7 0x5625e517ad1a in test__openat_syscall_event tests/openat-syscall.c:47
      rib#8 0x5625e51528e6 in run_test tests/builtin-test.c:358
      rib#9 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      rib#10 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      rib#11 0x5625e515572f in cmd_test tests/builtin-test.c:722
      rib#12 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      rib#13 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      rib#14 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      rib#15 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      rib#16 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

His patch took care of evsel->prev_raw_counts, but the above backtraces
are about evsel->counts, so fix that instead.

Reported-by: Changbin Du <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Mar 29, 2019
…_event_on_all_cpus test

  =================================================================
  ==7497==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 40 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a88f30 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedf30)
      rib#1 0x5625e5326213 in cpu_map__trim_new util/cpumap.c:45
      rib#2 0x5625e5326703 in cpu_map__read util/cpumap.c:103
      rib#3 0x5625e53267ef in cpu_map__read_all_cpu_map util/cpumap.c:120
      rib#4 0x5625e5326915 in cpu_map__new util/cpumap.c:135
      rib#5 0x5625e517b355 in test__openat_syscall_event_on_all_cpus tests/openat-syscall-all-cpus.c:36
      rib#6 0x5625e51528e6 in run_test tests/builtin-test.c:358
      rib#7 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      rib#8 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      rib#9 0x5625e515572f in cmd_test tests/builtin-test.c:722
      rib#10 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      rib#11 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      rib#12 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      rib#13 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      rib#14 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Fixes: f30a79b ("perf tools: Add reference counting for cpu_map object")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Mar 29, 2019
  =================================================================
  ==7506==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 13 byte(s) in 3 object(s) allocated from:
      #0 0x7f03339d6070 in __interceptor_strdup (/usr/lib/x86_64-linux-gnu/libasan.so.5+0x3b070)
      rib#1 0x5625e53aaef0 in expr__find_other util/expr.y:221
      rib#2 0x5625e51bcd3f in test__expr tests/expr.c:52
      rib#3 0x5625e51528e6 in run_test tests/builtin-test.c:358
      rib#4 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      rib#5 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      rib#6 0x5625e515572f in cmd_test tests/builtin-test.c:722
      rib#7 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      rib#8 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      rib#9 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      rib#10 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      rib#11 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Fixes: 0751673 ("perf tools: Add a simple expression parser for JSON")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Mar 29, 2019
  =================================================================
  ==20875==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 1160 byte(s) in 1 object(s) allocated from:
      #0 0x7f1b6fc84138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      rib#1 0x55bd50005599 in zalloc util/util.h:23
      rib#2 0x55bd500068f5 in perf_evsel__newtp_idx util/evsel.c:327
      rib#3 0x55bd4ff810fc in perf_evsel__newtp /home/work/linux/tools/perf/util/evsel.h:216
      rib#4 0x55bd4ff81608 in test__perf_evsel__tp_sched_test tests/evsel-tp-sched.c:69
      rib#5 0x55bd4ff528e6 in run_test tests/builtin-test.c:358
      rib#6 0x55bd4ff52baf in test_and_print tests/builtin-test.c:388
      rib#7 0x55bd4ff543fe in __cmd_test tests/builtin-test.c:583
      rib#8 0x55bd4ff5572f in cmd_test tests/builtin-test.c:722
      rib#9 0x55bd4ffc4087 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      rib#10 0x55bd4ffc45c6 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      rib#11 0x55bd4ffc49ca in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      rib#12 0x55bd4ffc5138 in main /home/changbin/work/linux/tools/perf/perf.c:520
      rib#13 0x7f1b6e34809a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  Indirect leak of 19 byte(s) in 1 object(s) allocated from:
      #0 0x7f1b6fc83f30 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedf30)
      rib#1 0x7f1b6e3ac30f in vasprintf (/lib/x86_64-linux-gnu/libc.so.6+0x8830f)

Signed-off-by: Changbin Du <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Fixes: 6a6cd11 ("perf test: Add test for the sched tracepoint format fields")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Apr 2, 2019
…mory

When halting a guest, QEMU flushes the virtual ITS caches, which
amounts to writing to the various tables that the guest has allocated.

When doing this, we fail to take the srcu lock, and the kernel
shouts loudly if running a lockdep kernel:

[   69.680416] =============================
[   69.680819] WARNING: suspicious RCU usage
[   69.681526] 5.1.0-rc1-00008-g600025238f51-dirty rib#18 Not tainted
[   69.682096] -----------------------------
[   69.682501] ./include/linux/kvm_host.h:605 suspicious rcu_dereference_check() usage!
[   69.683225]
[   69.683225] other info that might help us debug this:
[   69.683225]
[   69.683975]
[   69.683975] rcu_scheduler_active = 2, debug_locks = 1
[   69.684598] 6 locks held by qemu-system-aar/4097:
[   69.685059]  #0: 0000000034196013 (&kvm->lock){+.+.}, at: vgic_its_set_attr+0x244/0x3a0
[   69.686087]  rib#1: 00000000f2ed935e (&its->its_lock){+.+.}, at: vgic_its_set_attr+0x250/0x3a0
[   69.686919]  rib#2: 000000005e71ea54 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.687698]  rib#3: 00000000c17e548d (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.688475]  rib#4: 00000000ba386017 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.689978]  rib#5: 00000000c2c3c335 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[   69.690729]
[   69.690729] stack backtrace:
[   69.691151] CPU: 2 PID: 4097 Comm: qemu-system-aar Not tainted 5.1.0-rc1-00008-g600025238f51-dirty rib#18
[   69.691984] Hardware name: rockchip evb_rk3399/evb_rk3399, BIOS 2019.04-rc3-00124-g2feec69fb1 03/15/2019
[   69.692831] Call trace:
[   69.694072]  lockdep_rcu_suspicious+0xcc/0x110
[   69.694490]  gfn_to_memslot+0x174/0x190
[   69.694853]  kvm_write_guest+0x50/0xb0
[   69.695209]  vgic_its_save_tables_v0+0x248/0x330
[   69.695639]  vgic_its_set_attr+0x298/0x3a0
[   69.696024]  kvm_device_ioctl_attr+0x9c/0xd8
[   69.696424]  kvm_device_ioctl+0x8c/0xf8
[   69.696788]  do_vfs_ioctl+0xc8/0x960
[   69.697128]  ksys_ioctl+0x8c/0xa0
[   69.697445]  __arm64_sys_ioctl+0x28/0x38
[   69.697817]  el0_svc_common+0xd8/0x138
[   69.698173]  el0_svc_handler+0x38/0x78
[   69.698528]  el0_svc+0x8/0xc

The fix is to obviously take the srcu lock, just like we do on the
read side of things since bf30824. One wonders why this wasn't
fixed at the same time, but hey...

Fixes: bf30824 ("KVM: arm/arm64: VGIC/ITS: protect kvm_read_guest() calls with SRCU lock")
Signed-off-by: Marc Zyngier <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Apr 2, 2019
Calling kvm_is_visible_gfn() implies that we're parsing the memslots,
and doing this without the srcu lock is frown upon:

[12704.164532] =============================
[12704.164544] WARNING: suspicious RCU usage
[12704.164560] 5.1.0-rc1-00008-g600025238f51-dirty rib#16 Tainted: G        W
[12704.164573] -----------------------------
[12704.164589] ./include/linux/kvm_host.h:605 suspicious rcu_dereference_check() usage!
[12704.164602] other info that might help us debug this:
[12704.164616] rcu_scheduler_active = 2, debug_locks = 1
[12704.164631] 6 locks held by qemu-system-aar/13968:
[12704.164644]  #0: 000000007ebdae4f (&kvm->lock){+.+.}, at: vgic_its_set_attr+0x244/0x3a0
[12704.164691]  rib#1: 000000007d751022 (&its->its_lock){+.+.}, at: vgic_its_set_attr+0x250/0x3a0
[12704.164726]  rib#2: 00000000219d2706 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[12704.164761]  rib#3: 00000000a760aecd (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[12704.164794]  rib#4: 000000000ef8e31d (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[12704.164827]  rib#5: 000000007a872093 (&vcpu->mutex){+.+.}, at: lock_all_vcpus+0x64/0xd0
[12704.164861] stack backtrace:
[12704.164878] CPU: 2 PID: 13968 Comm: qemu-system-aar Tainted: G        W         5.1.0-rc1-00008-g600025238f51-dirty rib#16
[12704.164887] Hardware name: rockchip evb_rk3399/evb_rk3399, BIOS 2019.04-rc3-00124-g2feec69fb1 03/15/2019
[12704.164896] Call trace:
[12704.164910]  dump_backtrace+0x0/0x138
[12704.164920]  show_stack+0x24/0x30
[12704.164934]  dump_stack+0xbc/0x104
[12704.164946]  lockdep_rcu_suspicious+0xcc/0x110
[12704.164958]  gfn_to_memslot+0x174/0x190
[12704.164969]  kvm_is_visible_gfn+0x28/0x70
[12704.164980]  vgic_its_check_id.isra.0+0xec/0x1e8
[12704.164991]  vgic_its_save_tables_v0+0x1ac/0x330
[12704.165001]  vgic_its_set_attr+0x298/0x3a0
[12704.165012]  kvm_device_ioctl_attr+0x9c/0xd8
[12704.165022]  kvm_device_ioctl+0x8c/0xf8
[12704.165035]  do_vfs_ioctl+0xc8/0x960
[12704.165045]  ksys_ioctl+0x8c/0xa0
[12704.165055]  __arm64_sys_ioctl+0x28/0x38
[12704.165067]  el0_svc_common+0xd8/0x138
[12704.165078]  el0_svc_handler+0x38/0x78
[12704.165089]  el0_svc+0x8/0xc

Make sure the lock is taken when doing this.

Fixes: bf30824 ("KVM: arm/arm64: VGIC/ITS: protect kvm_read_guest() calls with SRCU lock")
Reviewed-by: Eric Auger <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Apr 8, 2019
Syzkaller report this:

kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [rib#1] SMP KASAN PTI
CPU: 0 PID: 4378 Comm: syz-executor.0 Tainted: G         C        5.0.0+ rib#5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
RIP: 0010:__lock_acquire+0x95b/0x3200 kernel/locking/lockdep.c:3573
Code: 00 0f 85 28 1e 00 00 48 81 c4 08 01 00 00 5b 5d 41 5c 41 5d 41 5e 41 5f c3 4c 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 cc 24 00 00 49 81 7d 00 e0 de 03 a6 41 bc 00 00
RSP: 0018:ffff8881e3c07a40 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000080
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffff8881e3c07d98 R11: ffff8881c7f21f80 R12: 0000000000000001
R13: 0000000000000080 R14: 0000000000000000 R15: 0000000000000001
FS:  00007fce2252e700(0000) GS:ffff8881f2400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffc7eb0228 CR3: 00000001e5bea002 CR4: 00000000007606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 lock_acquire+0xff/0x2c0 kernel/locking/lockdep.c:4211
 __mutex_lock_common kernel/locking/mutex.c:925 [inline]
 __mutex_lock+0xdf/0x1050 kernel/locking/mutex.c:1072
 drain_workqueue+0x24/0x3f0 kernel/workqueue.c:2934
 destroy_workqueue+0x23/0x630 kernel/workqueue.c:4319
 __do_sys_delete_module kernel/module.c:1018 [inline]
 __se_sys_delete_module kernel/module.c:961 [inline]
 __x64_sys_delete_module+0x30c/0x480 kernel/module.c:961
 do_syscall_64+0x9f/0x450 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x462e99
Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fce2252dc58 EFLAGS: 00000246 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462e99
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000140
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fce2252e6bc
R13: 00000000004bcca9 R14: 00000000006f6b48 R15: 00000000ffffffff

If alloc_workqueue fails, it should return -ENOMEM, otherwise may
trigger this NULL pointer dereference while unloading drivers.

Reported-by: Hulk Robot <[email protected]>
Fixes: 0a38c17 ("fm10k: Remove create_workqueue")
Signed-off-by: Yue Haibing <[email protected]>
Tested-by: Andrew Bowers <[email protected]>
Signed-off-by: Jeff Kirsher <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue May 17, 2019
Ido Schimmel says:

====================
mlxsw: Various fixes

This patchset contains various small fixes for mlxsw.

Patch rib#1 fixes a warning generated by switchdev core when the driver
fails to insert an MDB entry in the commit phase.

Patches rib#2-rib#4 fix a warning in check_flush_dependency() that can be
triggered when a work item in a WQ_MEM_RECLAIM workqueue tries to flush
a non-WQ_MEM_RECLAIM workqueue.

It seems that the semantics of the WQ_MEM_RECLAIM flag are not very
clear [1] and that various patches have been sent to remove it from
various workqueues throughout the kernel [2][3][4] in order to silence
the warning.

These patches do the same for the workqueues created by mlxsw that
probably should not have been created with this flag in the first place.

Patch rib#5 fixes a regression where an IP address cannot be assigned to a
VRF upper due to erroneous MAC validation check. Patch rib#6 adds a test
case.

Patch rib#7 adjusts Spectrum-2 shared buffer configuration to be compatible
with Spectrum-1. The problem and fix are described in detail in the
commit message.

Please consider patches rib#1-rib#5 for 5.0.y. I verified they apply cleanly.

[1] https://patchwork.kernel.org/patch/10791315/
[2] Commit ce162bf ("mac80211_hwsim: don't use WQ_MEM_RECLAIM")
[3] Commit 39baf10 ("IB/core: Fix use workqueue without WQ_MEM_RECLAIM")
[4] Commit 75215e5 ("iwcm: Don't allocate iwcm workqueue with WQ_MEM_RECLAIM")
====================

Signed-off-by: David S. Miller <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue May 17, 2019
Syzkaller report this:

BUG: unable to handle kernel paging request at fffffbfff830524b
PGD 237fe8067 P4D 237fe8067 PUD 237e64067 PMD 1c9716067 PTE 0
Oops: 0000 [rib#1] SMP KASAN PTI
CPU: 1 PID: 4465 Comm: syz-executor.0 Not tainted 5.0.0+ rib#5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
RIP: 0010:__list_add_valid+0x21/0xe0 lib/list_debug.c:23
Code: 8b 0c 24 e9 17 fd ff ff 90 55 48 89 fd 48 8d 7a 08 53 48 89 d3 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 48 83 ec 08 <80> 3c 02 00 0f 85 8b 00 00 00 48 8b 53 08 48 39 f2 75 35 48 89 f2
RSP: 0018:ffff8881ea2278d0 EFLAGS: 00010282
RAX: dffffc0000000000 RBX: ffffffffc1829250 RCX: 1ffff1103d444ef4
RDX: 1ffffffff830524b RSI: ffffffff85659300 RDI: ffffffffc1829258
RBP: ffffffffc1879250 R08: fffffbfff0acb269 R09: fffffbfff0acb269
R10: ffff8881ea2278f0 R11: fffffbfff0acb268 R12: ffffffffc1829250
R13: dffffc0000000000 R14: 0000000000000008 R15: ffffffffc187c830
FS:  00007fe0361df700(0000) GS:ffff8881f7300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff830524b CR3: 00000001eb39a001 CR4: 00000000007606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 __list_add include/linux/list.h:60 [inline]
 list_add include/linux/list.h:79 [inline]
 proto_register+0x444/0x8f0 net/core/sock.c:3375
 nr_proto_init+0x73/0x4b3 [netrom]
 ? 0xffffffffc1628000
 ? 0xffffffffc1628000
 do_one_initcall+0xbc/0x47d init/main.c:887
 do_init_module+0x1b5/0x547 kernel/module.c:3456
 load_module+0x6405/0x8c10 kernel/module.c:3804
 __do_sys_finit_module+0x162/0x190 kernel/module.c:3898
 do_syscall_64+0x9f/0x450 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x462e99
Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe0361dec58 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462e99
RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000003
RBP: 00007fe0361dec70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0361df6bc
R13: 00000000004bcefa R14: 00000000006f6fb0 R15: 0000000000000004
Modules linked in: netrom(+) ax25 fcrypt pcbc af_alg arizona_ldo1 v4l2_common videodev media v4l2_dv_timings hdlc ide_cd_mod snd_soc_sigmadsp_regmap snd_soc_sigmadsp intel_spi_platform intel_spi mtd spi_nor snd_usbmidi_lib usbcore lcd ti_ads7950 hi6421_regulator snd_soc_kbl_rt5663_max98927 snd_soc_hdac_hdmi snd_hda_ext_core snd_hda_core snd_soc_rt5663 snd_soc_core snd_pcm_dmaengine snd_compress snd_soc_rl6231 mac80211 rtc_rc5t583 spi_slave_time leds_pwm hid_gt683r hid industrialio_triggered_buffer kfifo_buf industrialio ir_kbd_i2c rc_core led_class_flash dwc_xlgmac snd_ymfpci gameport snd_mpu401_uart snd_rawmidi snd_ac97_codec snd_pcm ac97_bus snd_opl3_lib snd_timer snd_seq_device snd_hwdep snd soundcore iptable_security iptable_raw iptable_mangle iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter bpfilter ip6_vti ip_vti ip_gre ipip sit tunnel4 ip_tunnel hsr veth netdevsim vxcan batman_adv cfg80211 rfkill chnl_net caif nlmon dummy team bonding vcan
 bridge stp llc ip6_gre gre ip6_tunnel tunnel6 tun joydev mousedev ppdev tpm kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel ide_pci_generic piix aesni_intel aes_x86_64 crypto_simd cryptd glue_helper ide_core psmouse input_leds i2c_piix4 serio_raw intel_agp intel_gtt ata_generic agpgart pata_acpi parport_pc rtc_cmos parport floppy sch_fq_codel ip_tables x_tables sha1_ssse3 sha1_generic ipv6 [last unloaded: rxrpc]
Dumping ftrace buffer:
   (ftrace buffer empty)
CR2: fffffbfff830524b
---[ end trace 039ab24b305c4b19 ]---

If nr_proto_init failed, it may forget to call proto_unregister,
tiggering this issue.This patch rearrange code of nr_proto_init
to avoid such issues.

Reported-by: Hulk Robot <[email protected]>
Signed-off-by: YueHaibing <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue May 17, 2019
By calling maps__insert() we assume to get 2 references on the map,
which we relese within maps__remove call.

However if there's already same map name, we currently don't bump the
reference and can crash, like:

  Program received signal SIGABRT, Aborted.
  0x00007ffff75e60f5 in raise () from /lib64/libc.so.6

  (gdb) bt
  #0  0x00007ffff75e60f5 in raise () from /lib64/libc.so.6
  rib#1  0x00007ffff75d0895 in abort () from /lib64/libc.so.6
  rib#2  0x00007ffff75d0769 in __assert_fail_base.cold () from /lib64/libc.so.6
  rib#3  0x00007ffff75de596 in __assert_fail () from /lib64/libc.so.6
  rib#4  0x00000000004fc006 in refcount_sub_and_test (i=1, r=0x1224e88) at tools/include/linux/refcount.h:131
  rib#5  refcount_dec_and_test (r=0x1224e88) at tools/include/linux/refcount.h:148
  rib#6  map__put (map=0x1224df0) at util/map.c:299
  rib#7  0x00000000004fdb95 in __maps__remove (map=0x1224df0, maps=0xb17d80) at util/map.c:953
  rib#8  maps__remove (maps=0xb17d80, map=0x1224df0) at util/map.c:959
  rib#9  0x00000000004f7d8a in map_groups__remove (map=<optimized out>, mg=<optimized out>) at util/map_groups.h:65
  rib#10 machine__process_ksymbol_unregister (sample=<optimized out>, event=0x7ffff7279670, machine=<optimized out>) at util/machine.c:728
  rib#11 machine__process_ksymbol (machine=<optimized out>, event=0x7ffff7279670, sample=<optimized out>) at util/machine.c:741
  rib#12 0x00000000004fffbb in perf_session__deliver_event (session=0xb11390, event=0x7ffff7279670, tool=0x7fffffffc7b0, file_offset=13936) at util/session.c:1362
  rib#13 0x00000000005039bb in do_flush (show_progress=false, oe=0xb17e80) at util/ordered-events.c:243
  rib#14 __ordered_events__flush (oe=0xb17e80, how=OE_FLUSH__ROUND, timestamp=<optimized out>) at util/ordered-events.c:322
  rib#15 0x00000000005005e4 in perf_session__process_user_event (session=session@entry=0xb11390, event=event@entry=0x7ffff72a4af8,
  ...

Add the map to the list and getting the reference event if we find the
map with same name.

Signed-off-by: Jiri Olsa <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Eric Saint-Etienne <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Song Liu <[email protected]>
Fixes: 1e62856 ("perf symbols: Fix slowness due to -ffunction-section")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Jul 9, 2019
Ido Schimmel says:

====================
mlxsw: Various fixes

This patchset contains various fixes for mlxsw.

Patch rib#1 fixes an hash polarization problem when a nexthop device is a
LAG device. This is caused by the fact that the same seed is used for
the LAG and ECMP hash functions.

Patch rib#2 fixes an issue in which the driver fails to refresh a nexthop
neighbour after it becomes dead. This prevents the nexthop from ever
being written to the adjacency table and used to forward traffic. Patch

Patch rib#4 fixes a wrong extraction of TOS value in flower offload code.
Patch rib#5 is a test case.

Patch rib#6 works around a buffer issue in Spectrum-2 by reducing the
default sizes of the shared buffer pools.

Patch rib#7 prevents prio-tagged packets from entering the switch when PVID
is removed from the bridge port.

Please consider patches rib#2, rib#4 and rib#6 for 5.1.y
====================

Signed-off-by: David S. Miller <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Jul 9, 2019
Puts range check before dereferencing the pointer.

Reproducer:

  # echo stacktrace > trace_options
  # echo 1 > events/enable
  # cat trace > /dev/null

KASAN report:

  ==================================================================
  BUG: KASAN: use-after-free in trace_stack_print+0x26b/0x2c0
  Read of size 8 at addr ffff888069d20000 by task cat/1953

  CPU: 0 PID: 1953 Comm: cat Not tainted 5.2.0-rc3+ rib#5
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
  Call Trace:
   dump_stack+0x8a/0xce
   print_address_description+0x60/0x224
   ? trace_stack_print+0x26b/0x2c0
   ? trace_stack_print+0x26b/0x2c0
   __kasan_report.cold+0x1a/0x3e
   ? trace_stack_print+0x26b/0x2c0
   kasan_report+0xe/0x20
   trace_stack_print+0x26b/0x2c0
   print_trace_line+0x6ea/0x14d0
   ? tracing_buffers_read+0x700/0x700
   ? trace_find_next_entry_inc+0x158/0x1d0
   s_show+0xea/0x310
   seq_read+0xaa7/0x10e0
   ? seq_escape+0x230/0x230
   __vfs_read+0x7c/0x100
   vfs_read+0x16c/0x3a0
   ksys_read+0x121/0x240
   ? kernel_write+0x110/0x110
   ? perf_trace_sys_enter+0x8a0/0x8a0
   ? syscall_slow_exit_work+0xa9/0x410
   do_syscall_64+0xb7/0x390
   ? prepare_exit_to_usermode+0x165/0x200
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7f867681f910
  Code: b6 fe ff ff 48 8d 3d 0f be 08 00 48 83 ec 08 e8 06 db 01 00 66 0f 1f 44 00 00 83 3d f9 2d 2c 00 00 75 10 b8 00 00 00 00 04
  RSP: 002b:00007ffdabf23488 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
  RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f867681f910
  RDX: 0000000000020000 RSI: 00007f8676cde000 RDI: 0000000000000003
  RBP: 00007f8676cde000 R08: ffffffffffffffff R09: 0000000000000000
  R10: 0000000000000871 R11: 0000000000000246 R12: 00007f8676cde000
  R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000000ec0

  Allocated by task 1214:
   save_stack+0x1b/0x80
   __kasan_kmalloc.constprop.0+0xc2/0xd0
   kmem_cache_alloc+0xaf/0x1a0
   getname_flags+0xd2/0x5b0
   do_sys_open+0x277/0x5a0
   do_syscall_64+0xb7/0x390
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

  Freed by task 1214:
   save_stack+0x1b/0x80
   __kasan_slab_free+0x12c/0x170
   kmem_cache_free+0x8a/0x1c0
   putname+0xe1/0x120
   do_sys_open+0x2c5/0x5a0
   do_syscall_64+0xb7/0x390
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

  The buggy address belongs to the object at ffff888069d20000
   which belongs to the cache names_cache of size 4096
  The buggy address is located 0 bytes inside of
   4096-byte region [ffff888069d20000, ffff888069d21000)
  The buggy address belongs to the page:
  page:ffffea0001a74800 refcount:1 mapcount:0 mapping:ffff88806ccd1380 index:0x0 compound_mapcount: 0
  flags: 0x100000000010200(slab|head)
  raw: 0100000000010200 dead000000000100 dead000000000200 ffff88806ccd1380
  raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
  page dumped because: kasan: bad access detected

  Memory state around the buggy address:
   ffff888069d1ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   ffff888069d1ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  >ffff888069d20000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                     ^
   ffff888069d20080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
   ffff888069d20100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ==================================================================

Link: http://lkml.kernel.org/r/[email protected]

Fixes: 4285f2f ("tracing: Remove the ULONG_MAX stack trace hackery")
Signed-off-by: Eiichi Tsukata <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Jul 9, 2019
It is possible for an irq triggered by channel0 to be received later
after clks are disabled once firmware loaded during sdma probe. If
that happens then clearing them by writing to SDMA_H_INTR won't work
and the kernel will hang processing infinite interrupts. Actually,
don't need interrupt triggered on channel0 since it's pollling
SDMA_H_STATSTOP to know channel0 done rather than interrupt in
current code, just clear BD_INTR to disable channel0 interrupt to
avoid the above case.
This issue was brought by commit 1d069bf ("dmaengine: imx-sdma:
ack channel 0 IRQ in the interrupt handler") which didn't take care
the above case.

Fixes: 1d069bf ("dmaengine: imx-sdma: ack channel 0 IRQ in the interrupt handler")
Cc: [email protected] rib#5.0+
Signed-off-by: Robin Gong <[email protected]>
Reported-by: Sven Van Asbroeck <[email protected]>
Tested-by: Sven Van Asbroeck <[email protected]>
Reviewed-by: Michael Olbrich <[email protected]>
Signed-off-by: Vinod Koul <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Dec 12, 2019
…eservation

Even if isochronous resources reservation fails, error code doesn't return
in pcm.hw_params callback.

Cc: <[email protected]> rib#5.3+
Fixes: 4f380d0 ("ALSA: oxfw: configure packet format in pcm.hw_params callback")
Signed-off-by: Takashi Sakamoto <[email protected]>
Link: https://lore.kernel.org/r/20191209151655.GA8090@workstation
Signed-off-by: Takashi Iwai <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Dec 12, 2019
…es reservation

Even if isochronous resources reservation fails, error code doesn't return
in pcm.hw_params callback.

Cc: <[email protected]> rib#5.3+
Fixes: 55162d2 ("ALSA: fireface: reserve/release isochronous resources in pcm.hw_params/hw_free callbacks")
Signed-off-by: Takashi Sakamoto <[email protected]>
Link: https://lore.kernel.org/r/20191209151655.GA8090@workstation
Signed-off-by: Takashi Iwai <[email protected]>
djdeath pushed a commit to djdeath/linux that referenced this issue Mar 17, 2020
<4>[  259.166718] WARNING: inconsistent lock state
<4>[  259.166725] 5.6.0-rc3-CI-CI_DRM_8038+ rib#1 Tainted: G     U
<4>[  259.166727] --------------------------------
<4>[  259.166731] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
<4>[  259.166741] rtcwake/4221 [HC0[0]:SC0[0]:HE1:SE1] takes:
<4>[  259.166745] ffffffff82635198 (rtc_lock){?...}, at: cmos_interrupt+0x18/0x100
<4>[  259.166768] {IN-HARDIRQ-W} state was registered at:
<4>[  259.166780]   lock_acquire+0xa7/0x1c0
<4>[  259.166790]   _raw_spin_lock+0x2a/0x40
<4>[  259.166799]   cmos_interrupt+0x18/0x100
<4>[  259.166808]   rtc_handler+0x75/0xc0
<4>[  259.166822]   acpi_ev_fixed_event_detect+0xf9/0x132
<4>[  259.166829]   acpi_ev_sci_xrupt_handler+0xb/0x28
<4>[  259.166838]   acpi_irq+0x13/0x30
<4>[  259.166849]   __handle_irq_event_percpu+0x41/0x2c0
<4>[  259.166859]   handle_irq_event_percpu+0x2b/0x70
<4>[  259.166868]   handle_irq_event+0x2f/0x50
<4>[  259.166875]   handle_fasteoi_irq+0x8e/0x150
<4>[  259.166883]   do_IRQ+0x7e/0x160
<4>[  259.166891]   ret_from_intr+0x0/0x35
<4>[  259.166898]   mwait_idle+0x7e/0x200
<4>[  259.166905]   do_idle+0x1bb/0x260
<4>[  259.166912]   cpu_startup_entry+0x14/0x20
<4>[  259.166921]   start_secondary+0x15f/0x1b0
<4>[  259.166929]   secondary_startup_64+0xa4/0xb0
<4>[  259.167264] irq event stamp: 41593
<4>[  259.167275] hardirqs last  enabled at (41593): [<ffffffff81a394e7>] _raw_spin_unlock_irqrestore+0x47/0x60
<4>[  259.167285] hardirqs last disabled at (41592): [<ffffffff81a3926d>] _raw_spin_lock_irqsave+0xd/0x50
<4>[  259.167296] softirqs last  enabled at (41568): [<ffffffff81e00385>] __do_softirq+0x385/0x47f
<4>[  259.167306] softirqs last disabled at (41561): [<ffffffff810babaa>] irq_exit+0xba/0xc0
<4>[  259.167309]
                  other info that might help us debug this:
<4>[  259.167312]  Possible unsafe locking scenario:

<4>[  259.167314]        CPU0
<4>[  259.167316]        ----
<4>[  259.167319]   lock(rtc_lock);
<4>[  259.167324]   <Interrupt>
<4>[  259.167326]     lock(rtc_lock);
<4>[  259.167332]
                   *** DEADLOCK ***

<4>[  259.167337] 6 locks held by rtcwake/4221:
<4>[  259.167665]  #0: ffff888175e89408 (sb_writers#5){.+.+}, at: vfs_write+0x1a4/0x1d0
<4>[  259.167687]  rib#1: ffff88816e112080 (&of->mutex){+.+.}, at: kernfs_fop_write+0xdd/0x1b0
<4>[  259.167706]  rib#2: ffff888179be85e0 (kn->count#236){.+.+}, at: kernfs_fop_write+0xe6/0x1b0
<4>[  259.167728]  rib#3: ffffffff82641e00 (system_transition_mutex){+.+.}, at: pm_suspend+0xb3/0x3b0
<4>[  259.167748]  rib#4: ffffffff826b3ea0 (acpi_scan_lock){+.+.}, at: acpi_suspend_begin+0x47/0x80
<4>[  259.167763]  rib#5: ffff888178f6b960 (&dev->mutex){....}, at: device_resume+0x92/0x1c0
<4>[  259.167778]
                  stack backtrace:
<4>[  259.167788] CPU: 1 PID: 4221 Comm: rtcwake Tainted: G     U            5.6.0-rc3-CI-CI_DRM_8038+ rib#1
<4>[  259.168106] Hardware name: Google Soraka/Soraka, BIOS MrChromebox-4.10 08/25/2019
<4>[  259.168110] Call Trace:
<4>[  259.168123]  dump_stack+0x71/0x9b
<4>[  259.168133]  mark_lock+0x49a/0x500
<4>[  259.168457]  ? print_shortest_lock_dependencies+0x200/0x200
<4>[  259.168469]  __lock_acquire+0x6d4/0x15d0
<4>[  259.168479]  ? __lock_acquire+0x460/0x15d0
<4>[  259.168490]  lock_acquire+0xa7/0x1c0
<4>[  259.168500]  ? cmos_interrupt+0x18/0x100
<4>[  259.168824]  _raw_spin_lock+0x2a/0x40
<4>[  259.168834]  ? cmos_interrupt+0x18/0x100
<4>[  259.168843]  cmos_interrupt+0x18/0x100
<4>[  259.169159]  cmos_resume+0x1fd/0x290
<4>[  259.169174]  ? __acpi_pm_set_device_wakeup+0x24/0x100
<4>[  259.169498]  pnp_bus_resume+0x5e/0x90
<4>[  259.169509]  ? pnp_bus_suspend+0x10/0x10
<4>[  259.169518]  dpm_run_callback+0x64/0x280
<4>[  259.169530]  device_resume+0xd4/0x1c0
<4>[  259.169540]  ? dpm_watchdog_set+0x60/0x60
<4>[  259.169860]  dpm_resume+0x106/0x410
<4>[  259.169870]  ? dpm_resume_early+0x38c/0x3e0
<4>[  259.169881]  dpm_resume_end+0x8/0x10
<4>[  259.170195]  suspend_devices_and_enter+0x16f/0xbe0
<4>[  259.170211]  ? rcu_read_lock_sched_held+0x4d/0x80
<4>[  259.170528]  pm_suspend+0x344/0x3b0
<4>[  259.170542]  state_store+0x78/0xe0
<4>[  259.170559]  kernfs_fop_write+0x112/0x1b0
<4>[  259.170579]  vfs_write+0xb9/0x1d0
<4>[  259.170896]  ksys_write+0x9f/0xe0
<4>[  259.170907]  do_syscall_64+0x4f/0x220
<4>[  259.170918]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4>[  259.171229] RIP: 0033:0x7f9b4f3cb154
<4>[  259.171240] Code: 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 8d 05 b1 07 2e 00 8b 00 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 66 90 41 54 55 49 89 d4 53 48 89 f5
<4>[  259.171245] RSP: 002b:00007ffc057ce438 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
<4>[  259.171253] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f9b4f3cb154
<4>[  259.171257] RDX: 0000000000000004 RSI: 000055f4b3d185a0 RDI: 000000000000000a
<4>[  259.171572] RBP: 000055f4b3d185a0 R08: 000055f4b3d165e0 R09: 00007f9b4fab7740
<4>[  259.171576] R10: 000055f4b3d14010 R11: 0000000000000246 R12: 000055f4b3d16500
<4>[  259.171580] R13: 0000000000000004 R14: 00007f9b4f6a32a0 R15: 00007f9b4f6a2760

Fixes: c6d3a27 ("rtc: cmos: acknowledge ACPI driven wake alarms upon resume")
Fixes: 311ee9c ("rtc: cmos: allow using ACPI for RTC alarm instead of HPET")
Signed-off-by: Chris Wilson <[email protected]>
Cc: Zhang Rui <[email protected]>
Cc: Alexandre Belloni <[email protected]>
Cc: Alessandro Zummo <[email protected]>
Cc: [email protected]
Cc: <[email protected]> # v4.18+
Signed-off-by: Jani Nikula <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Jun 17, 2021
We inadvertently create a dependency on mmap_sem with a whole chain.

This breaks any user who wants to take a lock and call rcu_barrier(),
while also taking that lock inside mmap_sem:

<4> [604.892532] ======================================================
<4> [604.892534] WARNING: possible circular locking dependency detected
<4> [604.892536] 5.6.0-rc7-CI-Patchwork_17096+ rib#1 Tainted: G     U
<4> [604.892537] ------------------------------------------------------
<4> [604.892538] kms_frontbuffer/2595 is trying to acquire lock:
<4> [604.892540] ffffffff8264a558 (rcu_state.barrier_mutex){+.+.}, at: rcu_barrier+0x23/0x190
<4> [604.892547]
but task is already holding lock:
<4> [604.892547] ffff888484716050 (reservation_ww_class_mutex){+.+.}, at: i915_gem_object_pin_to_display_plane+0x89/0x270 [i915]
<4> [604.892592]
which lock already depends on the new lock.
<4> [604.892593]
the existing dependency chain (in reverse order) is:
<4> [604.892594]
-> rib#6 (reservation_ww_class_mutex){+.+.}:
<4> [604.892597]        __ww_mutex_lock.constprop.15+0xc3/0x1090
<4> [604.892598]        ww_mutex_lock+0x39/0x70
<4> [604.892600]        dma_resv_lockdep+0x10e/0x1f5
<4> [604.892602]        do_one_initcall+0x58/0x300
<4> [604.892604]        kernel_init_freeable+0x17b/0x1dc
<4> [604.892605]        kernel_init+0x5/0x100
<4> [604.892606]        ret_from_fork+0x24/0x50
<4> [604.892607]
-> rib#5 (reservation_ww_class_acquire){+.+.}:
<4> [604.892609]        dma_resv_lockdep+0xec/0x1f5
<4> [604.892610]        do_one_initcall+0x58/0x300
<4> [604.892610]        kernel_init_freeable+0x17b/0x1dc
<4> [604.892611]        kernel_init+0x5/0x100
<4> [604.892612]        ret_from_fork+0x24/0x50
<4> [604.892613]
-> rib#4 (&mm->mmap_sem#2){++++}:
<4> [604.892615]        __might_fault+0x63/0x90
<4> [604.892617]        _copy_to_user+0x1e/0x80
<4> [604.892619]        perf_read+0x200/0x2b0
<4> [604.892621]        vfs_read+0x96/0x160
<4> [604.892622]        ksys_read+0x9f/0xe0
<4> [604.892623]        do_syscall_64+0x4f/0x220
<4> [604.892624]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4> [604.892625]
-> rib#3 (&cpuctx_mutex){+.+.}:
<4> [604.892626]        __mutex_lock+0x9a/0x9c0
<4> [604.892627]        perf_event_init_cpu+0xa4/0x140
<4> [604.892629]        perf_event_init+0x19d/0x1cd
<4> [604.892630]        start_kernel+0x362/0x4e4
<4> [604.892631]        secondary_startup_64+0xa4/0xb0
<4> [604.892631]
-> rib#2 (pmus_lock){+.+.}:
<4> [604.892633]        __mutex_lock+0x9a/0x9c0
<4> [604.892633]        perf_event_init_cpu+0x6b/0x140
<4> [604.892635]        cpuhp_invoke_callback+0x9b/0x9d0
<4> [604.892636]        _cpu_up+0xa2/0x140
<4> [604.892637]        do_cpu_up+0x61/0xa0
<4> [604.892639]        smp_init+0x57/0x96
<4> [604.892639]        kernel_init_freeable+0x87/0x1dc
<4> [604.892640]        kernel_init+0x5/0x100
<4> [604.892642]        ret_from_fork+0x24/0x50
<4> [604.892642]
-> rib#1 (cpu_hotplug_lock.rw_sem){++++}:
<4> [604.892643]        cpus_read_lock+0x34/0xd0
<4> [604.892644]        rcu_barrier+0xaa/0x190
<4> [604.892645]        kernel_init+0x21/0x100
<4> [604.892647]        ret_from_fork+0x24/0x50
<4> [604.892647]
-> #0 (rcu_state.barrier_mutex){+.+.}:
<4> [604.892649]        __lock_acquire+0x1328/0x15d0
<4> [604.892650]        lock_acquire+0xa7/0x1c0
<4> [604.892651]        __mutex_lock+0x9a/0x9c0
<4> [604.892652]        rcu_barrier+0x23/0x190
<4> [604.892680]        i915_gem_object_unbind+0x29d/0x3f0 [i915]
<4> [604.892707]        i915_gem_object_pin_to_display_plane+0x141/0x270 [i915]
<4> [604.892737]        intel_pin_and_fence_fb_obj+0xec/0x1f0 [i915]
<4> [604.892767]        intel_plane_pin_fb+0x3f/0xd0 [i915]
<4> [604.892797]        intel_prepare_plane_fb+0x13b/0x5c0 [i915]
<4> [604.892798]        drm_atomic_helper_prepare_planes+0x85/0x110
<4> [604.892827]        intel_atomic_commit+0xda/0x390 [i915]
<4> [604.892828]        drm_atomic_helper_set_config+0x57/0xa0
<4> [604.892830]        drm_mode_setcrtc+0x1c4/0x720
<4> [604.892830]        drm_ioctl_kernel+0xb0/0xf0
<4> [604.892831]        drm_ioctl+0x2e1/0x390
<4> [604.892833]        ksys_ioctl+0x7b/0x90
<4> [604.892835]        __x64_sys_ioctl+0x11/0x20
<4> [604.892835]        do_syscall_64+0x4f/0x220
<4> [604.892836]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4> [604.892837]

Changes since v1:
- Use (*values)[n++] in perf_read_one().
Changes since v2:
- Centrally allocate values.

Signed-off-by: Maarten Lankhorst <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Rodrigo Vivi <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue Jun 17, 2021
As previously noted in commit 66e4f4a ("rtc: cmos: Use
spin_lock_irqsave() in cmos_interrupt()"):

<4>[  254.192378] WARNING: inconsistent lock state
<4>[  254.192384] 5.12.0-rc1-CI-CI_DRM_9834+ rib#1 Not tainted
<4>[  254.192396] --------------------------------
<4>[  254.192400] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
<4>[  254.192409] rtcwake/5309 [HC0[0]:SC0[0]:HE1:SE1] takes:
<4>[  254.192429] ffffffff8263c5f8 (rtc_lock){?...}-{2:2}, at: cmos_interrupt+0x18/0x100
<4>[  254.192481] {IN-HARDIRQ-W} state was registered at:
<4>[  254.192488]   lock_acquire+0xd1/0x3d0
<4>[  254.192504]   _raw_spin_lock+0x2a/0x40
<4>[  254.192519]   cmos_interrupt+0x18/0x100
<4>[  254.192536]   rtc_handler+0x1f/0xc0
<4>[  254.192553]   acpi_ev_fixed_event_detect+0x109/0x13c
<4>[  254.192574]   acpi_ev_sci_xrupt_handler+0xb/0x28
<4>[  254.192596]   acpi_irq+0x13/0x30
<4>[  254.192620]   __handle_irq_event_percpu+0x43/0x2c0
<4>[  254.192641]   handle_irq_event_percpu+0x2b/0x70
<4>[  254.192661]   handle_irq_event+0x2f/0x50
<4>[  254.192680]   handle_fasteoi_irq+0x9e/0x150
<4>[  254.192693]   __common_interrupt+0x76/0x140
<4>[  254.192715]   common_interrupt+0x96/0xc0
<4>[  254.192732]   asm_common_interrupt+0x1e/0x40
<4>[  254.192750]   _raw_spin_unlock_irqrestore+0x38/0x60
<4>[  254.192767]   resume_irqs+0xba/0xf0
<4>[  254.192786]   dpm_resume_noirq+0x245/0x3d0
<4>[  254.192811]   suspend_devices_and_enter+0x230/0xaa0
<4>[  254.192835]   pm_suspend.cold.8+0x301/0x34a
<4>[  254.192859]   state_store+0x7b/0xe0
<4>[  254.192879]   kernfs_fop_write_iter+0x11d/0x1c0
<4>[  254.192899]   new_sync_write+0x11d/0x1b0
<4>[  254.192916]   vfs_write+0x265/0x390
<4>[  254.192933]   ksys_write+0x5a/0xd0
<4>[  254.192949]   do_syscall_64+0x33/0x80
<4>[  254.192965]   entry_SYSCALL_64_after_hwframe+0x44/0xae
<4>[  254.192986] irq event stamp: 43775
<4>[  254.192994] hardirqs last  enabled at (43775): [<ffffffff81c00c42>] asm_sysvec_apic_timer_interrupt+0x12/0x20
<4>[  254.193023] hardirqs last disabled at (43774): [<ffffffff81aa691a>] sysvec_apic_timer_interrupt+0xa/0xb0
<4>[  254.193049] softirqs last  enabled at (42548): [<ffffffff81e00342>] __do_softirq+0x342/0x48e
<4>[  254.193074] softirqs last disabled at (42543): [<ffffffff810b45fd>] irq_exit_rcu+0xad/0xd0
<4>[  254.193101]
                  other info that might help us debug this:
<4>[  254.193107]  Possible unsafe locking scenario:

<4>[  254.193112]        CPU0
<4>[  254.193117]        ----
<4>[  254.193121]   lock(rtc_lock);
<4>[  254.193137]   <Interrupt>
<4>[  254.193142]     lock(rtc_lock);
<4>[  254.193156]
                   *** DEADLOCK ***

<4>[  254.193161] 6 locks held by rtcwake/5309:
<4>[  254.193174]  #0: ffff888104861430 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x5a/0xd0
<4>[  254.193232]  rib#1: ffff88810f823288 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0xe7/0x1c0
<4>[  254.193282]  rib#2: ffff888100cef3c0 (kn->active#285
<7>[  254.192706] i915 0000:00:02.0: [drm:intel_modeset_setup_hw_state [i915]] [CRTC:51:pipe A] hw state readout: disabled
<4>[  254.193307] ){.+.+}-{0:0}, at: kernfs_fop_write_iter+0xf0/0x1c0
<4>[  254.193333]  rib#3: ffffffff82649fa8 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend.cold.8+0xce/0x34a
<4>[  254.193387]  rib#4: ffffffff827a2108 (acpi_scan_lock){+.+.}-{3:3}, at: acpi_suspend_begin+0x47/0x70
<4>[  254.193433]  rib#5: ffff8881019ea178 (&dev->mutex){....}-{3:3}, at: device_resume+0x68/0x1e0
<4>[  254.193485]
                  stack backtrace:
<4>[  254.193492] CPU: 1 PID: 5309 Comm: rtcwake Not tainted 5.12.0-rc1-CI-CI_DRM_9834+ rib#1
<4>[  254.193514] Hardware name: Google Soraka/Soraka, BIOS MrChromebox-4.10 08/25/2019
<4>[  254.193524] Call Trace:
<4>[  254.193536]  dump_stack+0x7f/0xad
<4>[  254.193567]  mark_lock.part.47+0x8ca/0xce0
<4>[  254.193604]  __lock_acquire+0x39b/0x2590
<4>[  254.193626]  ? asm_sysvec_apic_timer_interrupt+0x12/0x20
<4>[  254.193660]  lock_acquire+0xd1/0x3d0
<4>[  254.193677]  ? cmos_interrupt+0x18/0x100
<4>[  254.193716]  _raw_spin_lock+0x2a/0x40
<4>[  254.193735]  ? cmos_interrupt+0x18/0x100
<4>[  254.193758]  cmos_interrupt+0x18/0x100
<4>[  254.193785]  cmos_resume+0x2ac/0x2d0
<4>[  254.193813]  ? acpi_pm_set_device_wakeup+0x1f/0x110
<4>[  254.193842]  ? pnp_bus_suspend+0x10/0x10
<4>[  254.193864]  pnp_bus_resume+0x5e/0x90
<4>[  254.193885]  dpm_run_callback+0x5f/0x240
<4>[  254.193914]  device_resume+0xb2/0x1e0
<4>[  254.193942]  ? pm_dev_err+0x25/0x25
<4>[  254.193974]  dpm_resume+0xea/0x3f0
<4>[  254.194005]  dpm_resume_end+0x8/0x10
<4>[  254.194030]  suspend_devices_and_enter+0x29b/0xaa0
<4>[  254.194066]  pm_suspend.cold.8+0x301/0x34a
<4>[  254.194094]  state_store+0x7b/0xe0
<4>[  254.194124]  kernfs_fop_write_iter+0x11d/0x1c0
<4>[  254.194151]  new_sync_write+0x11d/0x1b0
<4>[  254.194183]  vfs_write+0x265/0x390
<4>[  254.194207]  ksys_write+0x5a/0xd0
<4>[  254.194232]  do_syscall_64+0x33/0x80
<4>[  254.194251]  entry_SYSCALL_64_after_hwframe+0x44/0xae
<4>[  254.194274] RIP: 0033:0x7f07d79691e7
<4>[  254.194293] Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
<4>[  254.194312] RSP: 002b:00007ffd9cc2c768 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
<4>[  254.194337] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f07d79691e7
<4>[  254.194352] RDX: 0000000000000004 RSI: 0000556ebfc63590 RDI: 000000000000000b
<4>[  254.194366] RBP: 0000556ebfc63590 R08: 0000000000000000 R09: 0000000000000004
<4>[  254.194379] R10: 0000556ebf0ec2a6 R11: 0000000000000246 R12: 0000000000000004

which breaks S3-resume on fi-kbl-soraka presumably as that's slow enough
to trigger the alarm during the suspend.

Fixes: 6950d04 ("rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ")
References: 66e4f4a ("rtc: cmos: Use spin_lock_irqsave() in cmos_interrupt()"):
Signed-off-by: Chris Wilson <[email protected]>
Cc: Xiaofei Tan <[email protected]>
Cc: Alexandre Belloni <[email protected]>
Cc: Alessandro Zummo <[email protected]>
Cc: Ville Syrjälä <[email protected]>
Signed-off-by: Rodrigo Vivi <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue May 24, 2022
As reported by Alan, the CFI (Call Frame Information) in the VDSO time
routines is incorrect since commit ce7d805 ("powerpc/vdso: Prepare
for switching VDSO to generic C implementation.").

DWARF has a concept called the CFA (Canonical Frame Address), which on
powerpc is calculated as an offset from the stack pointer (r1). That
means when the stack pointer is changed there must be a corresponding
CFI directive to update the calculation of the CFA.

The current code is missing those directives for the changes to r1,
which prevents gdb from being able to generate a backtrace from inside
VDSO functions, eg:

  Breakpoint 1, 0x00007ffff7f804dc in __kernel_clock_gettime ()
  (gdb) bt
  #0  0x00007ffff7f804dc in __kernel_clock_gettime ()
  rib#1  0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6
  rib#2  0x00007fffffffd960 in ?? ()
  rib#3  0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6
  Backtrace stopped: frame did not save the PC

Alan helpfully describes some rules for correctly maintaining the CFI information:

  1) Every adjustment to the current frame address reg (ie. r1) must be
     described, and exactly at the instruction where r1 changes. Why?
     Because stack unwinding might want to access previous frames.

  2) If a function changes LR or any non-volatile register, the save
     location for those regs must be given. The CFI can be at any
     instruction after the saves up to the point that the reg is
     changed.
     (Exception: LR save should be described before a bl. not after)

  3) If asychronous unwind info is needed then restores of LR and
     non-volatile regs must also be described. The CFI can be at any
     instruction after the reg is restored up to the point where the
     save location is (potentially) trashed.

Fix the inability to backtrace by adding CFI directives describing the
changes to r1, ie. satisfying rule 1.

Also change the information for LR to point to the copy saved on the
stack, not the value in r0 that will be overwritten by the function
call.

Finally, add CFI directives describing the save/restore of r2.

With the fix gdb can correctly back trace and navigate up and down the stack:

  Breakpoint 1, 0x00007ffff7f804dc in __kernel_clock_gettime ()
  (gdb) bt
  #0  0x00007ffff7f804dc in __kernel_clock_gettime ()
  rib#1  0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6
  rib#2  0x0000000100015b60 in gettime ()
  rib#3  0x000000010000c8bc in print_long_format ()
  rib#4  0x000000010000d180 in print_current_files ()
  rib#5  0x00000001000054ac in main ()
  (gdb) up
  rib#1  0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6
  (gdb)
  rib#2  0x0000000100015b60 in gettime ()
  (gdb)
  rib#3  0x000000010000c8bc in print_long_format ()
  (gdb)
  rib#4  0x000000010000d180 in print_current_files ()
  (gdb)
  rib#5  0x00000001000054ac in main ()
  (gdb)
  Initial frame selected; you cannot go up.
  (gdb) down
  rib#4  0x000000010000d180 in print_current_files ()
  (gdb)
  rib#3  0x000000010000c8bc in print_long_format ()
  (gdb)
  rib#2  0x0000000100015b60 in gettime ()
  (gdb)
  rib#1  0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6
  (gdb)
  #0  0x00007ffff7f804dc in __kernel_clock_gettime ()
  (gdb)

Fixes: ce7d805 ("powerpc/vdso: Prepare for switching VDSO to generic C implementation.")
Cc: [email protected] # v5.11+
Reported-by: Alan Modra <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Reviewed-by: Segher Boessenkool <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
matt-auld pushed a commit to matt-auld/linux that referenced this issue May 24, 2022
Do not allow to write timestamps on RX rings if PF is being configured.
When PF is being configured RX rings can be freed or rebuilt. If at the
same time timestamps are updated, the kernel will crash by dereferencing
null RX ring pointer.

PID: 1449   TASK: ff187d28ed658040  CPU: 34  COMMAND: "ice-ptp-0000:51"
 #0 [ff1966a94a713bb0] machine_kexec at ffffffff9d05a0be
 rib#1 [ff1966a94a713c08] __crash_kexec at ffffffff9d192e9d
 rib#2 [ff1966a94a713cd0] crash_kexec at ffffffff9d1941bd
 rib#3 [ff1966a94a713ce8] oops_end at ffffffff9d01bd54
 rib#4 [ff1966a94a713d08] no_context at ffffffff9d06bda4
 rib#5 [ff1966a94a713d60] __bad_area_nosemaphore at ffffffff9d06c10c
 rib#6 [ff1966a94a713da8] do_page_fault at ffffffff9d06cae4
 rib#7 [ff1966a94a713de0] page_fault at ffffffff9da0107e
    [exception RIP: ice_ptp_update_cached_phctime+91]
    RIP: ffffffffc076db8b  RSP: ff1966a94a713e98  RFLAGS: 00010246
    RAX: 16e3db9c6b7ccae4  RBX: ff187d269dd3c180  RCX: ff187d269cd4d018
    RDX: 0000000000000000  RSI: 0000000000000000  RDI: 0000000000000000
    RBP: ff187d269cfcc644   R8: ff187d339b9641b0   R9: 0000000000000000
    R10: 0000000000000002  R11: 0000000000000000  R12: ff187d269cfcc648
    R13: ffffffff9f128784  R14: ffffffff9d101b70  R15: ff187d269cfcc640
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 rib#8 [ff1966a94a713ea0] ice_ptp_periodic_work at ffffffffc076dbef [ice]
 rib#9 [ff1966a94a713ee0] kthread_worker_fn at ffffffff9d101c1b
 rib#10 [ff1966a94a713f10] kthread at ffffffff9d101b4d
 rib#11 [ff1966a94a713f50] ret_from_fork at ffffffff9da0023f

Fixes: 77a7811 ("ice: enable receive hardware timestamping")
Signed-off-by: Arkadiusz Kubalewski <[email protected]>
Reviewed-by: Michal Schmidt <[email protected]>
Tested-by: Dave Cain <[email protected]>
Tested-by: Gurucharan <[email protected]> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <[email protected]>
matt-auld pushed a commit to matt-auld/linux that referenced this issue May 24, 2022
The splat below can be seen when running kvm-unit-test:

     =============================
     WARNING: suspicious RCU usage
     5.18.0-rc7 rib#5 Tainted: G          IOE
     -----------------------------
     /home/kernel/linux/arch/x86/kvm/../../../virt/kvm/eventfd.c:80 RCU-list traversed in non-reader section!!

     other info that might help us debug this:

     rcu_scheduler_active = 2, debug_locks = 1
     4 locks held by qemu-system-x86/35124:
      #0: ffff9725391d80b8 (&vcpu->mutex){+.+.}-{4:4}, at: kvm_vcpu_ioctl+0x77/0x710 [kvm]
      rib#1: ffffbd25cfb2a0b8 (&kvm->srcu){....}-{0:0}, at: vcpu_enter_guest+0xdeb/0x1900 [kvm]
      rib#2: ffffbd25cfb2b920 (&kvm->irq_srcu){....}-{0:0}, at: kvm_hv_notify_acked_sint+0x79/0x1e0 [kvm]
      rib#3: ffffbd25cfb2b920 (&kvm->irq_srcu){....}-{0:0}, at: irqfd_resampler_ack+0x5/0x110 [kvm]

     stack backtrace:
     CPU: 2 PID: 35124 Comm: qemu-system-x86 Tainted: G          IOE     5.18.0-rc7 rib#5
     Call Trace:
      <TASK>
      dump_stack_lvl+0x6c/0x9b
      irqfd_resampler_ack+0xfd/0x110 [kvm]
      kvm_notify_acked_gsi+0x32/0x90 [kvm]
      kvm_hv_notify_acked_sint+0xc5/0x1e0 [kvm]
      kvm_hv_set_msr_common+0xec1/0x1160 [kvm]
      kvm_set_msr_common+0x7c3/0xf60 [kvm]
      vmx_set_msr+0x394/0x1240 [kvm_intel]
      kvm_set_msr_ignored_check+0x86/0x200 [kvm]
      kvm_emulate_wrmsr+0x4f/0x1f0 [kvm]
      vmx_handle_exit+0x6fb/0x7e0 [kvm_intel]
      vcpu_enter_guest+0xe5a/0x1900 [kvm]
      kvm_arch_vcpu_ioctl_run+0x16e/0xac0 [kvm]
      kvm_vcpu_ioctl+0x279/0x710 [kvm]
      __x64_sys_ioctl+0x83/0xb0
      do_syscall_64+0x3b/0x90
      entry_SYSCALL_64_after_hwframe+0x44/0xae

resampler-list is protected by irq_srcu (see kvm_irqfd_assign), so fix
the false positive by using list_for_each_entry_srcu().

Signed-off-by: Wanpeng Li <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
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