Is this repo deprecated? #3

cdbattags · 2020-01-28T21:49:36Z

It looks like the DockerHub images are pulling from https://github.com/linuxkit/linuxkit/blob/master/kernel/Dockerfile which in turn points to https://www.kernel.org/pub/linux/kernel/${KERNEL_MAJOR}/linux-${KERNEL_VERSION}.tar.xz.

Is this repo used anymore?

The text was updated successfully, but these errors were encountered:

justincormack · 2020-01-29T12:01:15Z

We use this to generate the patches that we add to the patch directories, rather than cloning this repo directly. So yes it is used, but you should not in general use this repo, as it does not necessarily have all the kernel patch releases in it.

commit 5c9934b upstream. We got another syzbot report [1] that tells us we must use write_lock_irq()/write_unlock_irq() to avoid possible deadlock. [1] WARNING: inconsistent lock state 5.5.0-rc1-syzkaller #0 Not tainted -------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-R} usage. syz-executor826/9605 [HC1[1]:SC0[0]:HE0:SE1] takes: ffffffff8a128718 (disc_data_lock){+-..}, at: sp_get.isra.0+0x1d/0xf0 drivers/net/ppp/ppp_synctty.c:138 {HARDIRQ-ON-W} state was registered at: lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485 __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline] _raw_write_lock_bh+0x33/0x50 kernel/locking/spinlock.c:319 sixpack_close+0x1d/0x250 drivers/net/hamradio/6pack.c:657 tty_ldisc_close.isra.0+0x119/0x1a0 drivers/tty/tty_ldisc.c:489 tty_set_ldisc+0x230/0x6b0 drivers/tty/tty_ldisc.c:585 tiocsetd drivers/tty/tty_io.c:2337 [inline] tty_ioctl+0xe8d/0x14f0 drivers/tty/tty_io.c:2597 vfs_ioctl fs/ioctl.c:47 [inline] file_ioctl fs/ioctl.c:545 [inline] do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732 ksys_ioctl+0xab/0xd0 fs/ioctl.c:749 __do_sys_ioctl fs/ioctl.c:756 [inline] __se_sys_ioctl fs/ioctl.c:754 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe irq event stamp: 3946 hardirqs last enabled at (3945): [<ffffffff87c86e43>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] hardirqs last enabled at (3945): [<ffffffff87c86e43>] _raw_spin_unlock_irq+0x23/0x80 kernel/locking/spinlock.c:199 hardirqs last disabled at (3946): [<ffffffff8100675f>] trace_hardirqs_off_thunk+0x1a/0x1c arch/x86/entry/thunk_64.S:42 softirqs last enabled at (2658): [<ffffffff86a8b4df>] spin_unlock_bh include/linux/spinlock.h:383 [inline] softirqs last enabled at (2658): [<ffffffff86a8b4df>] clusterip_netdev_event+0x46f/0x670 net/ipv4/netfilter/ipt_CLUSTERIP.c:222 softirqs last disabled at (2656): [<ffffffff86a8b22b>] spin_lock_bh include/linux/spinlock.h:343 [inline] softirqs last disabled at (2656): [<ffffffff86a8b22b>] clusterip_netdev_event+0x1bb/0x670 net/ipv4/netfilter/ipt_CLUSTERIP.c:196 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(disc_data_lock); <Interrupt> lock(disc_data_lock); *** DEADLOCK *** 5 locks held by syz-executor826/9605: #0: ffff8880a905e198 (&tty->legacy_mutex){+.+.}, at: tty_lock+0xc7/0x130 drivers/tty/tty_mutex.c:19 #1: ffffffff899a56c0 (rcu_read_lock){....}, at: mutex_spin_on_owner+0x0/0x330 kernel/locking/mutex.c:413 #2: ffff8880a496a2b0 (&(&i->lock)->rlock){-.-.}, at: spin_lock include/linux/spinlock.h:338 [inline] #2: ffff8880a496a2b0 (&(&i->lock)->rlock){-.-.}, at: serial8250_interrupt+0x2d/0x1a0 drivers/tty/serial/8250/8250_core.c:116 #3: ffffffff8c104048 (&port_lock_key){-.-.}, at: serial8250_handle_irq.part.0+0x24/0x330 drivers/tty/serial/8250/8250_port.c:1823 #4: ffff8880a905e090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref+0x22/0x90 drivers/tty/tty_ldisc.c:288 stack backtrace: CPU: 1 PID: 9605 Comm: syz-executor826 Not tainted 5.5.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_usage_bug.cold+0x327/0x378 kernel/locking/lockdep.c:3101 valid_state kernel/locking/lockdep.c:3112 [inline] mark_lock_irq kernel/locking/lockdep.c:3309 [inline] mark_lock+0xbb4/0x1220 kernel/locking/lockdep.c:3666 mark_usage kernel/locking/lockdep.c:3554 [inline] __lock_acquire+0x1e55/0x4a00 kernel/locking/lockdep.c:3909 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x50 kernel/locking/spinlock.c:223 sp_get.isra.0+0x1d/0xf0 drivers/net/ppp/ppp_synctty.c:138 sixpack_write_wakeup+0x25/0x340 drivers/net/hamradio/6pack.c:402 tty_wakeup+0xe9/0x120 drivers/tty/tty_io.c:536 tty_port_default_wakeup+0x2b/0x40 drivers/tty/tty_port.c:50 tty_port_tty_wakeup+0x57/0x70 drivers/tty/tty_port.c:387 uart_write_wakeup+0x46/0x70 drivers/tty/serial/serial_core.c:104 serial8250_tx_chars+0x495/0xaf0 drivers/tty/serial/8250/8250_port.c:1761 serial8250_handle_irq.part.0+0x2a2/0x330 drivers/tty/serial/8250/8250_port.c:1834 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1820 [inline] serial8250_default_handle_irq+0xc0/0x150 drivers/tty/serial/8250/8250_port.c:1850 serial8250_interrupt+0xf1/0x1a0 drivers/tty/serial/8250/8250_core.c:126 __handle_irq_event_percpu+0x15d/0x970 kernel/irq/handle.c:149 handle_irq_event_percpu+0x74/0x160 kernel/irq/handle.c:189 handle_irq_event+0xa7/0x134 kernel/irq/handle.c:206 handle_edge_irq+0x25e/0x8d0 kernel/irq/chip.c:830 generic_handle_irq_desc include/linux/irqdesc.h:156 [inline] do_IRQ+0xde/0x280 arch/x86/kernel/irq.c:250 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:607 </IRQ> RIP: 0010:cpu_relax arch/x86/include/asm/processor.h:685 [inline] RIP: 0010:mutex_spin_on_owner+0x247/0x330 kernel/locking/mutex.c:579 Code: c3 be 08 00 00 00 4c 89 e7 e8 e5 06 59 00 4c 89 e0 48 c1 e8 03 42 80 3c 38 00 0f 85 e1 00 00 00 49 8b 04 24 a8 01 75 96 f3 90 <e9> 2f fe ff ff 0f 0b e8 0d 19 09 00 84 c0 0f 85 ff fd ff ff 48 c7 RSP: 0018:ffffc90001eafa20 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffd7 RAX: 0000000000000000 RBX: ffff88809fd9e0c0 RCX: 1ffffffff13266dd RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000 RBP: ffffc90001eafa60 R08: 1ffff11013d22898 R09: ffffed1013d22899 R10: ffffed1013d22898 R11: ffff88809e9144c7 R12: ffff8880a905e138 R13: ffff88809e9144c0 R14: 0000000000000000 R15: dffffc0000000000 mutex_optimistic_spin kernel/locking/mutex.c:673 [inline] __mutex_lock_common kernel/locking/mutex.c:962 [inline] __mutex_lock+0x32b/0x13c0 kernel/locking/mutex.c:1106 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1121 tty_lock+0xc7/0x130 drivers/tty/tty_mutex.c:19 tty_release+0xb5/0xe90 drivers/tty/tty_io.c:1665 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x8e7/0x2ef0 kernel/exit.c:797 do_group_exit+0x135/0x360 kernel/exit.c:895 __do_sys_exit_group kernel/exit.c:906 [inline] __se_sys_exit_group kernel/exit.c:904 [inline] __x64_sys_exit_group+0x44/0x50 kernel/exit.c:904 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x43fef8 Code: Bad RIP value. RSP: 002b:00007ffdb07d2338 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043fef8 RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00000000004bf730 R08: 00000000000000e7 R09: ffffffffffffffd0 R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000 Fixes: 6e4e2f8 ("6pack,mkiss: fix lock inconsistency") Signed-off-by: Eric Dumazet <[email protected]> Reported-by: syzbot <[email protected]> Cc: Arnd Bergmann <[email protected]> Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

[ Upstream commit b7a0d65 ] With latest llvm compiler, running test_progs will have the following verifier failure for test_sysctl_loop1.o: libbpf: load bpf program failed: Permission denied libbpf: -- BEGIN DUMP LOG --- libbpf: invalid indirect read from stack var_off (0x0; 0xff)+196 size 7 ... libbpf: -- END LOG -- libbpf: failed to load program 'cgroup/sysctl' libbpf: failed to load object 'test_sysctl_loop1.o' The related bytecode looks as below: 0000000000000308 LBB0_8: 97: r4 = r10 98: r4 += -288 99: r4 += r7 100: w8 &= 255 101: r1 = r10 102: r1 += -488 103: r1 += r8 104: r2 = 7 105: r3 = 0 106: call 106 107: w1 = w0 108: w1 += -1 109: if w1 > 6 goto -24 <LBB0_5> 110: w0 += w8 111: r7 += 8 112: w8 = w0 113: if r7 != 224 goto -17 <LBB0_8> And source code: for (i = 0; i < ARRAY_SIZE(tcp_mem); ++i) { ret = bpf_strtoul(value + off, MAX_ULONG_STR_LEN, 0, tcp_mem + i); if (ret <= 0 || ret > MAX_ULONG_STR_LEN) return 0; off += ret & MAX_ULONG_STR_LEN; } Current verifier is not able to conclude that register w0 before '+' at insn 110 has a range of 1 to 7 and thinks it is from 0 - 255. This leads to more conservative range for w8 at insn 112, and later verifier complaint. Let us workaround this issue until we found a compiler and/or verifier solution. The workaround in this patch is to make variable 'ret' volatile, which will force a reload and then '&' operation to ensure better value range. With this patch, I got the below byte code for the loop: 0000000000000328 LBB0_9: 101: r4 = r10 102: r4 += -288 103: r4 += r7 104: w8 &= 255 105: r1 = r10 106: r1 += -488 107: r1 += r8 108: r2 = 7 109: r3 = 0 110: call 106 111: *(u32 *)(r10 - 64) = r0 112: r1 = *(u32 *)(r10 - 64) 113: if w1 s< 1 goto -28 <LBB0_5> 114: r1 = *(u32 *)(r10 - 64) 115: if w1 s> 7 goto -30 <LBB0_5> 116: r1 = *(u32 *)(r10 - 64) 117: w1 &= 7 118: w1 += w8 119: r7 += 8 120: w8 = w1 121: if r7 != 224 goto -21 <LBB0_9> Insn 117 did the '&' operation and we got more precise value range for 'w8' at insn 120. The test is happy then: #3/17 test_sysctl_loop1.o:OK Signed-off-by: Yonghong Song <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Song Liu <[email protected]> Link: https://lore.kernel.org/bpf/[email protected] Signed-off-by: Sasha Levin <[email protected]>

[ Upstream commit 32546a9 ] This patch moves the final part of the cifsFileInfo_put() logic where we need a write lock on lock_sem to be processed in a separate thread that holds no other locks. This is to prevent deadlocks like the one below: > there are 6 processes looping to while trying to down_write > cinode->lock_sem, 5 of them from _cifsFileInfo_put, and one from > cifs_new_fileinfo > > and there are 5 other processes which are blocked, several of them > waiting on either PG_writeback or PG_locked (which are both set), all > for the same page of the file > > 2 inode_lock() (inode->i_rwsem) for the file > 1 wait_on_page_writeback() for the page > 1 down_read(inode->i_rwsem) for the inode of the directory > 1 inode_lock()(inode->i_rwsem) for the inode of the directory > 1 __lock_page > > > so processes are blocked waiting on: > page flags PG_locked and PG_writeback for one specific page > inode->i_rwsem for the directory > inode->i_rwsem for the file > cifsInodeInflock_sem > > > > here are the more gory details (let me know if I need to provide > anything more/better): > > [0 00:48:22.765] [UN] PID: 8863 TASK: ffff8c691547c5c0 CPU: 3 > COMMAND: "reopen_file" > #0 [ffff9965007e3ba8] __schedule at ffffffff9b6e6095 > #1 [ffff9965007e3c38] schedule at ffffffff9b6e64df > #2 [ffff9965007e3c48] rwsem_down_write_slowpath at ffffffff9af283d7 > #3 [ffff9965007e3cb8] legitimize_path at ffffffff9b0f975d > #4 [ffff9965007e3d08] path_openat at ffffffff9b0fe55d > #5 [ffff9965007e3dd8] do_filp_open at ffffffff9b100a33 > #6 [ffff9965007e3ee0] do_sys_open at ffffffff9b0eb2d6 > #7 [ffff9965007e3f38] do_syscall_64 at ffffffff9ae04315 > * (I think legitimize_path is bogus) > > in path_openat > } else { > const char *s = path_init(nd, flags); > while (!(error = link_path_walk(s, nd)) && > (error = do_last(nd, file, op)) > 0) { <<<< > > do_last: > if (open_flag & O_CREAT) > inode_lock(dir->d_inode); <<<< > else > so it's trying to take inode->i_rwsem for the directory > > DENTRY INODE SUPERBLK TYPE PATH > ffff8c68bb8e79c0 ffff8c691158ef20 ffff8c6915bf9000 DIR /mnt/vm1_smb/ > inode.i_rwsem is ffff8c691158efc0 > > <struct rw_semaphore 0xffff8c691158efc0>: > owner: <struct task_struct 0xffff8c6914275d00> (UN - 8856 - > reopen_file), counter: 0x0000000000000003 > waitlist: 2 > 0xffff9965007e3c90 8863 reopen_file UN 0 1:29:22.926 > RWSEM_WAITING_FOR_WRITE > 0xffff996500393e00 9802 ls UN 0 1:17:26.700 > RWSEM_WAITING_FOR_READ > > > the owner of the inode.i_rwsem of the directory is: > > [0 00:00:00.109] [UN] PID: 8856 TASK: ffff8c6914275d00 CPU: 3 > COMMAND: "reopen_file" > #0 [ffff99650065b828] __schedule at ffffffff9b6e6095 > #1 [ffff99650065b8b8] schedule at ffffffff9b6e64df > #2 [ffff99650065b8c8] schedule_timeout at ffffffff9b6e9f89 > #3 [ffff99650065b940] msleep at ffffffff9af573a9 > #4 [ffff99650065b948] _cifsFileInfo_put.cold.63 at ffffffffc0a42dd6 [cifs] > #5 [ffff99650065ba38] cifs_writepage_locked at ffffffffc0a0b8f3 [cifs] > #6 [ffff99650065bab0] cifs_launder_page at ffffffffc0a0bb72 [cifs] > #7 [ffff99650065bb30] invalidate_inode_pages2_range at ffffffff9b04d4bd > #8 [ffff99650065bcb8] cifs_invalidate_mapping at ffffffffc0a11339 [cifs] > #9 [ffff99650065bcd0] cifs_revalidate_mapping at ffffffffc0a1139a [cifs] > #10 [ffff99650065bcf0] cifs_d_revalidate at ffffffffc0a014f6 [cifs] > #11 [ffff99650065bd08] path_openat at ffffffff9b0fe7f7 > #12 [ffff99650065bdd8] do_filp_open at ffffffff9b100a33 > #13 [ffff99650065bee0] do_sys_open at ffffffff9b0eb2d6 > #14 [ffff99650065bf38] do_syscall_64 at ffffffff9ae04315 > > cifs_launder_page is for page 0xffffd1e2c07d2480 > > crash> page.index,mapping,flags 0xffffd1e2c07d2480 > index = 0x8 > mapping = 0xffff8c68f3cd0db0 > flags = 0xfffffc0008095 > > PAGE-FLAG BIT VALUE > PG_locked 0 0000001 > PG_uptodate 2 0000004 > PG_lru 4 0000010 > PG_waiters 7 0000080 > PG_writeback 15 0008000 > > > inode is ffff8c68f3cd0c40 > inode.i_rwsem is ffff8c68f3cd0ce0 > DENTRY INODE SUPERBLK TYPE PATH > ffff8c68a1f1b480 ffff8c68f3cd0c40 ffff8c6915bf9000 REG > /mnt/vm1_smb/testfile.8853 > > > this process holds the inode->i_rwsem for the parent directory, is > laundering a page attached to the inode of the file it's opening, and in > _cifsFileInfo_put is trying to down_write the cifsInodeInflock_sem > for the file itself. > > > <struct rw_semaphore 0xffff8c68f3cd0ce0>: > owner: <struct task_struct 0xffff8c6914272e80> (UN - 8854 - > reopen_file), counter: 0x0000000000000003 > waitlist: 1 > 0xffff9965005dfd80 8855 reopen_file UN 0 1:29:22.912 > RWSEM_WAITING_FOR_WRITE > > this is the inode.i_rwsem for the file > > the owner: > > [0 00:48:22.739] [UN] PID: 8854 TASK: ffff8c6914272e80 CPU: 2 > COMMAND: "reopen_file" > #0 [ffff99650054fb38] __schedule at ffffffff9b6e6095 > #1 [ffff99650054fbc8] schedule at ffffffff9b6e64df > #2 [ffff99650054fbd8] io_schedule at ffffffff9b6e68e2 > #3 [ffff99650054fbe8] __lock_page at ffffffff9b03c56f > #4 [ffff99650054fc80] pagecache_get_page at ffffffff9b03dcdf > #5 [ffff99650054fcc0] grab_cache_page_write_begin at ffffffff9b03ef4c > #6 [ffff99650054fcd0] cifs_write_begin at ffffffffc0a064ec [cifs] > #7 [ffff99650054fd30] generic_perform_write at ffffffff9b03bba4 > #8 [ffff99650054fda8] __generic_file_write_iter at ffffffff9b04060a > #9 [ffff99650054fdf0] cifs_strict_writev.cold.70 at ffffffffc0a4469b [cifs] > #10 [ffff99650054fe48] new_sync_write at ffffffff9b0ec1dd > #11 [ffff99650054fed0] vfs_write at ffffffff9b0eed35 > #12 [ffff99650054ff00] ksys_write at ffffffff9b0eefd9 > #13 [ffff99650054ff38] do_syscall_64 at ffffffff9ae04315 > > the process holds the inode->i_rwsem for the file to which it's writing, > and is trying to __lock_page for the same page as in the other processes > > > the other tasks: > [0 00:00:00.028] [UN] PID: 8859 TASK: ffff8c6915479740 CPU: 2 > COMMAND: "reopen_file" > #0 [ffff9965007b39d8] __schedule at ffffffff9b6e6095 > #1 [ffff9965007b3a68] schedule at ffffffff9b6e64df > #2 [ffff9965007b3a78] schedule_timeout at ffffffff9b6e9f89 > #3 [ffff9965007b3af0] msleep at ffffffff9af573a9 > #4 [ffff9965007b3af8] cifs_new_fileinfo.cold.61 at ffffffffc0a42a07 [cifs] > #5 [ffff9965007b3b78] cifs_open at ffffffffc0a0709d [cifs] > #6 [ffff9965007b3cd8] do_dentry_open at ffffffff9b0e9b7a > #7 [ffff9965007b3d08] path_openat at ffffffff9b0fe34f > #8 [ffff9965007b3dd8] do_filp_open at ffffffff9b100a33 > #9 [ffff9965007b3ee0] do_sys_open at ffffffff9b0eb2d6 > #10 [ffff9965007b3f38] do_syscall_64 at ffffffff9ae04315 > > this is opening the file, and is trying to down_write cinode->lock_sem > > > [0 00:00:00.041] [UN] PID: 8860 TASK: ffff8c691547ae80 CPU: 2 > COMMAND: "reopen_file" > [0 00:00:00.057] [UN] PID: 8861 TASK: ffff8c6915478000 CPU: 3 > COMMAND: "reopen_file" > [0 00:00:00.059] [UN] PID: 8858 TASK: ffff8c6914271740 CPU: 2 > COMMAND: "reopen_file" > [0 00:00:00.109] [UN] PID: 8862 TASK: ffff8c691547dd00 CPU: 6 > COMMAND: "reopen_file" > #0 [ffff9965007c3c78] __schedule at ffffffff9b6e6095 > #1 [ffff9965007c3d08] schedule at ffffffff9b6e64df > #2 [ffff9965007c3d18] schedule_timeout at ffffffff9b6e9f89 > #3 [ffff9965007c3d90] msleep at ffffffff9af573a9 > #4 [ffff9965007c3d98] _cifsFileInfo_put.cold.63 at ffffffffc0a42dd6 [cifs] > #5 [ffff9965007c3e88] cifs_close at ffffffffc0a07aaf [cifs] > #6 [ffff9965007c3ea0] __fput at ffffffff9b0efa6e > #7 [ffff9965007c3ee8] task_work_run at ffffffff9aef1614 > #8 [ffff9965007c3f20] exit_to_usermode_loop at ffffffff9ae03d6f > #9 [ffff9965007c3f38] do_syscall_64 at ffffffff9ae0444c > > closing the file, and trying to down_write cifsi->lock_sem > > > [0 00:48:22.839] [UN] PID: 8857 TASK: ffff8c6914270000 CPU: 7 > COMMAND: "reopen_file" > #0 [ffff9965006a7cc8] __schedule at ffffffff9b6e6095 > #1 [ffff9965006a7d58] schedule at ffffffff9b6e64df > #2 [ffff9965006a7d68] io_schedule at ffffffff9b6e68e2 > #3 [ffff9965006a7d78] wait_on_page_bit at ffffffff9b03cac6 > #4 [ffff9965006a7e10] __filemap_fdatawait_range at ffffffff9b03b028 > #5 [ffff9965006a7ed8] filemap_write_and_wait at ffffffff9b040165 > #6 [ffff9965006a7ef0] cifs_flush at ffffffffc0a0c2fa [cifs] > #7 [ffff9965006a7f10] filp_close at ffffffff9b0e93f1 > #8 [ffff9965006a7f30] __x64_sys_close at ffffffff9b0e9a0e > #9 [ffff9965006a7f38] do_syscall_64 at ffffffff9ae04315 > > in __filemap_fdatawait_range > wait_on_page_writeback(page); > for the same page of the file > > > > [0 00:48:22.718] [UN] PID: 8855 TASK: ffff8c69142745c0 CPU: 7 > COMMAND: "reopen_file" > #0 [ffff9965005dfc98] __schedule at ffffffff9b6e6095 > #1 [ffff9965005dfd28] schedule at ffffffff9b6e64df > #2 [ffff9965005dfd38] rwsem_down_write_slowpath at ffffffff9af283d7 > #3 [ffff9965005dfdf0] cifs_strict_writev at ffffffffc0a0c40a [cifs] > #4 [ffff9965005dfe48] new_sync_write at ffffffff9b0ec1dd > #5 [ffff9965005dfed0] vfs_write at ffffffff9b0eed35 > #6 [ffff9965005dff00] ksys_write at ffffffff9b0eefd9 > #7 [ffff9965005dff38] do_syscall_64 at ffffffff9ae04315 > > inode_lock(inode); > > > and one 'ls' later on, to see whether the rest of the mount is available > (the test file is in the root, so we get blocked up on the directory > ->i_rwsem), so the entire mount is unavailable > > [0 00:36:26.473] [UN] PID: 9802 TASK: ffff8c691436ae80 CPU: 4 > COMMAND: "ls" > #0 [ffff996500393d28] __schedule at ffffffff9b6e6095 > #1 [ffff996500393db8] schedule at ffffffff9b6e64df > #2 [ffff996500393dc8] rwsem_down_read_slowpath at ffffffff9b6e9421 > #3 [ffff996500393e78] down_read_killable at ffffffff9b6e95e2 > #4 [ffff996500393e88] iterate_dir at ffffffff9b103c56 > #5 [ffff996500393ec8] ksys_getdents64 at ffffffff9b104b0c > #6 [ffff996500393f30] __x64_sys_getdents64 at ffffffff9b104bb6 > #7 [ffff996500393f38] do_syscall_64 at ffffffff9ae04315 > > in iterate_dir: > if (shared) > res = down_read_killable(&inode->i_rwsem); <<<< > else > res = down_write_killable(&inode->i_rwsem); > Reported-by: Frank Sorenson <[email protected]> Reviewed-by: Pavel Shilovsky <[email protected]> Signed-off-by: Ronnie Sahlberg <[email protected]> Signed-off-by: Steve French <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

commit 5c9934b upstream. We got another syzbot report [1] that tells us we must use write_lock_irq()/write_unlock_irq() to avoid possible deadlock. [1] WARNING: inconsistent lock state 5.5.0-rc1-syzkaller #0 Not tainted -------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-R} usage. syz-executor826/9605 [HC1[1]:SC0[0]:HE0:SE1] takes: ffffffff8a128718 (disc_data_lock){+-..}, at: sp_get.isra.0+0x1d/0xf0 drivers/net/ppp/ppp_synctty.c:138 {HARDIRQ-ON-W} state was registered at: lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485 __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline] _raw_write_lock_bh+0x33/0x50 kernel/locking/spinlock.c:319 sixpack_close+0x1d/0x250 drivers/net/hamradio/6pack.c:657 tty_ldisc_close.isra.0+0x119/0x1a0 drivers/tty/tty_ldisc.c:489 tty_set_ldisc+0x230/0x6b0 drivers/tty/tty_ldisc.c:585 tiocsetd drivers/tty/tty_io.c:2337 [inline] tty_ioctl+0xe8d/0x14f0 drivers/tty/tty_io.c:2597 vfs_ioctl fs/ioctl.c:47 [inline] file_ioctl fs/ioctl.c:545 [inline] do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732 ksys_ioctl+0xab/0xd0 fs/ioctl.c:749 __do_sys_ioctl fs/ioctl.c:756 [inline] __se_sys_ioctl fs/ioctl.c:754 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe irq event stamp: 3946 hardirqs last enabled at (3945): [<ffffffff87c86e43>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] hardirqs last enabled at (3945): [<ffffffff87c86e43>] _raw_spin_unlock_irq+0x23/0x80 kernel/locking/spinlock.c:199 hardirqs last disabled at (3946): [<ffffffff8100675f>] trace_hardirqs_off_thunk+0x1a/0x1c arch/x86/entry/thunk_64.S:42 softirqs last enabled at (2658): [<ffffffff86a8b4df>] spin_unlock_bh include/linux/spinlock.h:383 [inline] softirqs last enabled at (2658): [<ffffffff86a8b4df>] clusterip_netdev_event+0x46f/0x670 net/ipv4/netfilter/ipt_CLUSTERIP.c:222 softirqs last disabled at (2656): [<ffffffff86a8b22b>] spin_lock_bh include/linux/spinlock.h:343 [inline] softirqs last disabled at (2656): [<ffffffff86a8b22b>] clusterip_netdev_event+0x1bb/0x670 net/ipv4/netfilter/ipt_CLUSTERIP.c:196 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(disc_data_lock); <Interrupt> lock(disc_data_lock); *** DEADLOCK *** 5 locks held by syz-executor826/9605: #0: ffff8880a905e198 (&tty->legacy_mutex){+.+.}, at: tty_lock+0xc7/0x130 drivers/tty/tty_mutex.c:19 #1: ffffffff899a56c0 (rcu_read_lock){....}, at: mutex_spin_on_owner+0x0/0x330 kernel/locking/mutex.c:413 #2: ffff8880a496a2b0 (&(&i->lock)->rlock){-.-.}, at: spin_lock include/linux/spinlock.h:338 [inline] #2: ffff8880a496a2b0 (&(&i->lock)->rlock){-.-.}, at: serial8250_interrupt+0x2d/0x1a0 drivers/tty/serial/8250/8250_core.c:116 #3: ffffffff8c104048 (&port_lock_key){-.-.}, at: serial8250_handle_irq.part.0+0x24/0x330 drivers/tty/serial/8250/8250_port.c:1823 #4: ffff8880a905e090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref+0x22/0x90 drivers/tty/tty_ldisc.c:288 stack backtrace: CPU: 1 PID: 9605 Comm: syz-executor826 Not tainted 5.5.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_usage_bug.cold+0x327/0x378 kernel/locking/lockdep.c:3101 valid_state kernel/locking/lockdep.c:3112 [inline] mark_lock_irq kernel/locking/lockdep.c:3309 [inline] mark_lock+0xbb4/0x1220 kernel/locking/lockdep.c:3666 mark_usage kernel/locking/lockdep.c:3554 [inline] __lock_acquire+0x1e55/0x4a00 kernel/locking/lockdep.c:3909 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x50 kernel/locking/spinlock.c:223 sp_get.isra.0+0x1d/0xf0 drivers/net/ppp/ppp_synctty.c:138 sixpack_write_wakeup+0x25/0x340 drivers/net/hamradio/6pack.c:402 tty_wakeup+0xe9/0x120 drivers/tty/tty_io.c:536 tty_port_default_wakeup+0x2b/0x40 drivers/tty/tty_port.c:50 tty_port_tty_wakeup+0x57/0x70 drivers/tty/tty_port.c:387 uart_write_wakeup+0x46/0x70 drivers/tty/serial/serial_core.c:104 serial8250_tx_chars+0x495/0xaf0 drivers/tty/serial/8250/8250_port.c:1761 serial8250_handle_irq.part.0+0x2a2/0x330 drivers/tty/serial/8250/8250_port.c:1834 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1820 [inline] serial8250_default_handle_irq+0xc0/0x150 drivers/tty/serial/8250/8250_port.c:1850 serial8250_interrupt+0xf1/0x1a0 drivers/tty/serial/8250/8250_core.c:126 __handle_irq_event_percpu+0x15d/0x970 kernel/irq/handle.c:149 handle_irq_event_percpu+0x74/0x160 kernel/irq/handle.c:189 handle_irq_event+0xa7/0x134 kernel/irq/handle.c:206 handle_edge_irq+0x25e/0x8d0 kernel/irq/chip.c:830 generic_handle_irq_desc include/linux/irqdesc.h:156 [inline] do_IRQ+0xde/0x280 arch/x86/kernel/irq.c:250 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:607 </IRQ> RIP: 0010:cpu_relax arch/x86/include/asm/processor.h:685 [inline] RIP: 0010:mutex_spin_on_owner+0x247/0x330 kernel/locking/mutex.c:579 Code: c3 be 08 00 00 00 4c 89 e7 e8 e5 06 59 00 4c 89 e0 48 c1 e8 03 42 80 3c 38 00 0f 85 e1 00 00 00 49 8b 04 24 a8 01 75 96 f3 90 <e9> 2f fe ff ff 0f 0b e8 0d 19 09 00 84 c0 0f 85 ff fd ff ff 48 c7 RSP: 0018:ffffc90001eafa20 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffd7 RAX: 0000000000000000 RBX: ffff88809fd9e0c0 RCX: 1ffffffff13266dd RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000 RBP: ffffc90001eafa60 R08: 1ffff11013d22898 R09: ffffed1013d22899 R10: ffffed1013d22898 R11: ffff88809e9144c7 R12: ffff8880a905e138 R13: ffff88809e9144c0 R14: 0000000000000000 R15: dffffc0000000000 mutex_optimistic_spin kernel/locking/mutex.c:673 [inline] __mutex_lock_common kernel/locking/mutex.c:962 [inline] __mutex_lock+0x32b/0x13c0 kernel/locking/mutex.c:1106 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1121 tty_lock+0xc7/0x130 drivers/tty/tty_mutex.c:19 tty_release+0xb5/0xe90 drivers/tty/tty_io.c:1665 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x8e7/0x2ef0 kernel/exit.c:797 do_group_exit+0x135/0x360 kernel/exit.c:895 __do_sys_exit_group kernel/exit.c:906 [inline] __se_sys_exit_group kernel/exit.c:904 [inline] __x64_sys_exit_group+0x44/0x50 kernel/exit.c:904 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x43fef8 Code: Bad RIP value. RSP: 002b:00007ffdb07d2338 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043fef8 RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00000000004bf730 R08: 00000000000000e7 R09: ffffffffffffffd0 R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000 Fixes: 6e4e2f8 ("6pack,mkiss: fix lock inconsistency") Signed-off-by: Eric Dumazet <[email protected]> Reported-by: syzbot <[email protected]> Cc: Arnd Bergmann <[email protected]> Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

commit 334b0f4 upstream. There is a race condition which results in a deadlock when rmdir and mkdir execute concurrently: $ ls /sys/fs/resctrl/c1/mon_groups/m1/ cpus cpus_list mon_data tasks Thread 1: rmdir /sys/fs/resctrl/c1 Thread 2: mkdir /sys/fs/resctrl/c1/mon_groups/m1 3 locks held by mkdir/48649: #0: (sb_writers#17){.+.+}, at: [<ffffffffb4ca2aa0>] mnt_want_write+0x20/0x50 #1: (&type->i_mutex_dir_key#8/1){+.+.}, at: [<ffffffffb4c8c13b>] filename_create+0x7b/0x170 #2: (rdtgroup_mutex){+.+.}, at: [<ffffffffb4a4389d>] rdtgroup_kn_lock_live+0x3d/0x70 4 locks held by rmdir/48652: #0: (sb_writers#17){.+.+}, at: [<ffffffffb4ca2aa0>] mnt_want_write+0x20/0x50 #1: (&type->i_mutex_dir_key#8/1){+.+.}, at: [<ffffffffb4c8c3cf>] do_rmdir+0x13f/0x1e0 #2: (&type->i_mutex_dir_key#8){++++}, at: [<ffffffffb4c86d5d>] vfs_rmdir+0x4d/0x120 #3: (rdtgroup_mutex){+.+.}, at: [<ffffffffb4a4389d>] rdtgroup_kn_lock_live+0x3d/0x70 Thread 1 is deleting control group "c1". Holding rdtgroup_mutex, kernfs_remove() removes all kernfs nodes under directory "c1" recursively, then waits for sub kernfs node "mon_groups" to drop active reference. Thread 2 is trying to create a subdirectory "m1" in the "mon_groups" directory. The wrapper kernfs_iop_mkdir() takes an active reference to the "mon_groups" directory but the code drops the active reference to the parent directory "c1" instead. As a result, Thread 1 is blocked on waiting for active reference to drop and never release rdtgroup_mutex, while Thread 2 is also blocked on trying to get rdtgroup_mutex. Thread 1 (rdtgroup_rmdir) Thread 2 (rdtgroup_mkdir) (rmdir /sys/fs/resctrl/c1) (mkdir /sys/fs/resctrl/c1/mon_groups/m1) ------------------------- ------------------------- kernfs_iop_mkdir /* * kn: "m1", parent_kn: "mon_groups", * prgrp_kn: parent_kn->parent: "c1", * * "mon_groups", parent_kn->active++: 1 */ kernfs_get_active(parent_kn) kernfs_iop_rmdir /* "c1", kn->active++ */ kernfs_get_active(kn) rdtgroup_kn_lock_live atomic_inc(&rdtgrp->waitcount) /* "c1", kn->active-- */ kernfs_break_active_protection(kn) mutex_lock rdtgroup_rmdir_ctrl free_all_child_rdtgrp sentry->flags = RDT_DELETED rdtgroup_ctrl_remove rdtgrp->flags = RDT_DELETED kernfs_get(kn) kernfs_remove(rdtgrp->kn) __kernfs_remove /* "mon_groups", sub_kn */ atomic_add(KN_DEACTIVATED_BIAS, &sub_kn->active) kernfs_drain(sub_kn) /* * sub_kn->active == KN_DEACTIVATED_BIAS + 1, * waiting on sub_kn->active to drop, but it * never drops in Thread 2 which is blocked * on getting rdtgroup_mutex. */ Thread 1 hangs here ----> wait_event(sub_kn->active == KN_DEACTIVATED_BIAS) ... rdtgroup_mkdir rdtgroup_mkdir_mon(parent_kn, prgrp_kn) mkdir_rdt_prepare(parent_kn, prgrp_kn) rdtgroup_kn_lock_live(prgrp_kn) atomic_inc(&rdtgrp->waitcount) /* * "c1", prgrp_kn->active-- * * The active reference on "c1" is * dropped, but not matching the * actual active reference taken * on "mon_groups", thus causing * Thread 1 to wait forever while * holding rdtgroup_mutex. */ kernfs_break_active_protection( prgrp_kn) /* * Trying to get rdtgroup_mutex * which is held by Thread 1. */ Thread 2 hangs here ----> mutex_lock ... The problem is that the creation of a subdirectory in the "mon_groups" directory incorrectly releases the active protection of its parent directory instead of itself before it starts waiting for rdtgroup_mutex. This is triggered by the rdtgroup_mkdir() flow calling rdtgroup_kn_lock_live()/rdtgroup_kn_unlock() with kernfs node of the parent control group ("c1") as argument. It should be called with kernfs node "mon_groups" instead. What is currently missing is that the kn->priv of "mon_groups" is NULL instead of pointing to the rdtgrp. Fix it by pointing kn->priv to rdtgrp when "mon_groups" is created. Then it could be passed to rdtgroup_kn_lock_live()/rdtgroup_kn_unlock() instead. And then it operates on the same rdtgroup structure but handles the active reference of kernfs node "mon_groups" to prevent deadlock. The same changes are also made to the "mon_data" directories. This results in some unused function parameters that will be cleaned up in follow-up patch as the focus here is on the fix only in support of backporting efforts. Backporting notes: Since upstream commit fa7d949 ("x86/resctrl: Rename and move rdt files to a separate directory"), the file arch/x86/kernel/cpu/intel_rdt_rdtgroup.c has been renamed and moved to arch/x86/kernel/cpu/resctrl/rdtgroup.c. Apply the change against file arch/x86/kernel/cpu/intel_rdt_rdtgroup.c for older stable trees. Fixes: c7d9aac ("x86/intel_rdt/cqm: Add mkdir support for RDT monitoring") Suggested-by: Reinette Chatre <[email protected]> Signed-off-by: Xiaochen Shen <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Reinette Chatre <[email protected]> Reviewed-by: Tony Luck <[email protected]> Acked-by: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Sasha Levin <[email protected]>

[ Upstream commit 42ffb0b ] There exists a deadlock with range_cyclic that has existed forever. If we loop around with a bio already built we could deadlock with a writer who has the page locked that we're attempting to write but is waiting on a page in our bio to be written out. The task traces are as follows PID: 1329874 TASK: ffff889ebcdf3800 CPU: 33 COMMAND: "kworker/u113:5" #0 [ffffc900297bb658] __schedule at ffffffff81a4c33f #1 [ffffc900297bb6e0] schedule at ffffffff81a4c6e3 #2 [ffffc900297bb6f8] io_schedule at ffffffff81a4ca42 #3 [ffffc900297bb708] __lock_page at ffffffff811f145b #4 [ffffc900297bb798] __process_pages_contig at ffffffff814bc502 #5 [ffffc900297bb8c8] lock_delalloc_pages at ffffffff814bc684 #6 [ffffc900297bb900] find_lock_delalloc_range at ffffffff814be9ff #7 [ffffc900297bb9a0] writepage_delalloc at ffffffff814bebd0 #8 [ffffc900297bba18] __extent_writepage at ffffffff814bfbf2 #9 [ffffc900297bba98] extent_write_cache_pages at ffffffff814bffbd PID: 2167901 TASK: ffff889dc6a59c00 CPU: 14 COMMAND: "aio-dio-invalid" #0 [ffffc9003b50bb18] __schedule at ffffffff81a4c33f #1 [ffffc9003b50bba0] schedule at ffffffff81a4c6e3 #2 [ffffc9003b50bbb8] io_schedule at ffffffff81a4ca42 #3 [ffffc9003b50bbc8] wait_on_page_bit at ffffffff811f24d6 #4 [ffffc9003b50bc60] prepare_pages at ffffffff814b05a7 #5 [ffffc9003b50bcd8] btrfs_buffered_write at ffffffff814b1359 #6 [ffffc9003b50bdb0] btrfs_file_write_iter at ffffffff814b5933 #7 [ffffc9003b50be38] new_sync_write at ffffffff8128f6a8 #8 [ffffc9003b50bec8] vfs_write at ffffffff81292b9d #9 [ffffc9003b50bf00] ksys_pwrite64 at ffffffff81293032 I used drgn to find the respective pages we were stuck on page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901 page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874 As you can see the kworker is waiting for bit 0 (PG_locked) on index 7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index 8148. aio-dio-invalid has 7680, and the kworker epd looks like the following crash> struct extent_page_data ffffc900297bbbb0 struct extent_page_data { bio = 0xffff889f747ed830, tree = 0xffff889eed6ba448, extent_locked = 0, sync_io = 0 } Probably worth mentioning as well that it waits for writeback of the page to complete while holding a lock on it (at prepare_pages()). Using drgn I walked the bio pages looking for page 0xffffea00fbfc7500 which is the one we're waiting for writeback on bio = Object(prog, 'struct bio', address=0xffff889f747ed830) for i in range(0, bio.bi_vcnt.value_()): bv = bio.bi_io_vec[i] if bv.bv_page.value_() == 0xffffea00fbfc7500: print("FOUND IT") which validated what I suspected. The fix for this is simple, flush the epd before we loop back around to the beginning of the file during writeout. Fixes: b293f02 ("Btrfs: Add writepages support") CC: [email protected] # 4.4+ Reviewed-by: Filipe Manana <[email protected]> Signed-off-by: Josef Bacik <[email protected]> Signed-off-by: David Sterba <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

commit 334b0f4 upstream. There is a race condition which results in a deadlock when rmdir and mkdir execute concurrently: $ ls /sys/fs/resctrl/c1/mon_groups/m1/ cpus cpus_list mon_data tasks Thread 1: rmdir /sys/fs/resctrl/c1 Thread 2: mkdir /sys/fs/resctrl/c1/mon_groups/m1 3 locks held by mkdir/48649: #0: (sb_writers#17){.+.+}, at: [<ffffffffb4ca2aa0>] mnt_want_write+0x20/0x50 #1: (&type->i_mutex_dir_key#8/1){+.+.}, at: [<ffffffffb4c8c13b>] filename_create+0x7b/0x170 #2: (rdtgroup_mutex){+.+.}, at: [<ffffffffb4a4389d>] rdtgroup_kn_lock_live+0x3d/0x70 4 locks held by rmdir/48652: #0: (sb_writers#17){.+.+}, at: [<ffffffffb4ca2aa0>] mnt_want_write+0x20/0x50 #1: (&type->i_mutex_dir_key#8/1){+.+.}, at: [<ffffffffb4c8c3cf>] do_rmdir+0x13f/0x1e0 #2: (&type->i_mutex_dir_key#8){++++}, at: [<ffffffffb4c86d5d>] vfs_rmdir+0x4d/0x120 #3: (rdtgroup_mutex){+.+.}, at: [<ffffffffb4a4389d>] rdtgroup_kn_lock_live+0x3d/0x70 Thread 1 is deleting control group "c1". Holding rdtgroup_mutex, kernfs_remove() removes all kernfs nodes under directory "c1" recursively, then waits for sub kernfs node "mon_groups" to drop active reference. Thread 2 is trying to create a subdirectory "m1" in the "mon_groups" directory. The wrapper kernfs_iop_mkdir() takes an active reference to the "mon_groups" directory but the code drops the active reference to the parent directory "c1" instead. As a result, Thread 1 is blocked on waiting for active reference to drop and never release rdtgroup_mutex, while Thread 2 is also blocked on trying to get rdtgroup_mutex. Thread 1 (rdtgroup_rmdir) Thread 2 (rdtgroup_mkdir) (rmdir /sys/fs/resctrl/c1) (mkdir /sys/fs/resctrl/c1/mon_groups/m1) ------------------------- ------------------------- kernfs_iop_mkdir /* * kn: "m1", parent_kn: "mon_groups", * prgrp_kn: parent_kn->parent: "c1", * * "mon_groups", parent_kn->active++: 1 */ kernfs_get_active(parent_kn) kernfs_iop_rmdir /* "c1", kn->active++ */ kernfs_get_active(kn) rdtgroup_kn_lock_live atomic_inc(&rdtgrp->waitcount) /* "c1", kn->active-- */ kernfs_break_active_protection(kn) mutex_lock rdtgroup_rmdir_ctrl free_all_child_rdtgrp sentry->flags = RDT_DELETED rdtgroup_ctrl_remove rdtgrp->flags = RDT_DELETED kernfs_get(kn) kernfs_remove(rdtgrp->kn) __kernfs_remove /* "mon_groups", sub_kn */ atomic_add(KN_DEACTIVATED_BIAS, &sub_kn->active) kernfs_drain(sub_kn) /* * sub_kn->active == KN_DEACTIVATED_BIAS + 1, * waiting on sub_kn->active to drop, but it * never drops in Thread 2 which is blocked * on getting rdtgroup_mutex. */ Thread 1 hangs here ----> wait_event(sub_kn->active == KN_DEACTIVATED_BIAS) ... rdtgroup_mkdir rdtgroup_mkdir_mon(parent_kn, prgrp_kn) mkdir_rdt_prepare(parent_kn, prgrp_kn) rdtgroup_kn_lock_live(prgrp_kn) atomic_inc(&rdtgrp->waitcount) /* * "c1", prgrp_kn->active-- * * The active reference on "c1" is * dropped, but not matching the * actual active reference taken * on "mon_groups", thus causing * Thread 1 to wait forever while * holding rdtgroup_mutex. */ kernfs_break_active_protection( prgrp_kn) /* * Trying to get rdtgroup_mutex * which is held by Thread 1. */ Thread 2 hangs here ----> mutex_lock ... The problem is that the creation of a subdirectory in the "mon_groups" directory incorrectly releases the active protection of its parent directory instead of itself before it starts waiting for rdtgroup_mutex. This is triggered by the rdtgroup_mkdir() flow calling rdtgroup_kn_lock_live()/rdtgroup_kn_unlock() with kernfs node of the parent control group ("c1") as argument. It should be called with kernfs node "mon_groups" instead. What is currently missing is that the kn->priv of "mon_groups" is NULL instead of pointing to the rdtgrp. Fix it by pointing kn->priv to rdtgrp when "mon_groups" is created. Then it could be passed to rdtgroup_kn_lock_live()/rdtgroup_kn_unlock() instead. And then it operates on the same rdtgroup structure but handles the active reference of kernfs node "mon_groups" to prevent deadlock. The same changes are also made to the "mon_data" directories. This results in some unused function parameters that will be cleaned up in follow-up patch as the focus here is on the fix only in support of backporting efforts. Backporting notes: Since upstream commit fa7d949 ("x86/resctrl: Rename and move rdt files to a separate directory"), the file arch/x86/kernel/cpu/intel_rdt_rdtgroup.c has been renamed and moved to arch/x86/kernel/cpu/resctrl/rdtgroup.c. Apply the change against file arch/x86/kernel/cpu/intel_rdt_rdtgroup.c for older stable trees. Fixes: c7d9aac ("x86/intel_rdt/cqm: Add mkdir support for RDT monitoring") Suggested-by: Reinette Chatre <[email protected]> Signed-off-by: Xiaochen Shen <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Reinette Chatre <[email protected]> Reviewed-by: Tony Luck <[email protected]> Acked-by: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Sasha Levin <[email protected]>

commit 1cfbb48 upstream. Confusingly, there are three SPSR layouts that a kernel may need to deal with: (1) An AArch64 SPSR_ELx view of an AArch64 pstate (2) An AArch64 SPSR_ELx view of an AArch32 pstate (3) An AArch32 SPSR_* view of an AArch32 pstate When the KVM AArch32 support code deals with SPSR_{EL2,HYP}, it's either dealing with #2 or #3 consistently. On arm64 the PSR_AA32_* definitions match the AArch64 SPSR_ELx view, and on arm the PSR_AA32_* definitions match the AArch32 SPSR_* view. However, when we inject an exception into an AArch32 guest, we have to synthesize the AArch32 SPSR_* that the guest will see. Thus, an AArch64 host needs to synthesize layout #3 from layout #2. This patch adds a new host_spsr_to_spsr32() helper for this, and makes use of it in the KVM AArch32 support code. For arm64 we need to shuffle the DIT bit around, and remove the SS bit, while for arm we can use the value as-is. I've open-coded the bit manipulation for now to avoid having to rework the existing PSR_* definitions into PSR64_AA32_* and PSR32_AA32_* definitions. I hope to perform a more thorough refactoring in future so that we can handle pstate view manipulation more consistently across the kernel tree. Signed-off-by: Mark Rutland <[email protected]> Signed-off-by: Marc Zyngier <[email protected]> Reviewed-by: Alexandru Elisei <[email protected]> Cc: [email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>

[ Upstream commit 96bf313ecb33567af4cb53928b0c951254a02759 ] There exists a deadlock with range_cyclic that has existed forever. If we loop around with a bio already built we could deadlock with a writer who has the page locked that we're attempting to write but is waiting on a page in our bio to be written out. The task traces are as follows PID: 1329874 TASK: ffff889ebcdf3800 CPU: 33 COMMAND: "kworker/u113:5" #0 [ffffc900297bb658] __schedule at ffffffff81a4c33f #1 [ffffc900297bb6e0] schedule at ffffffff81a4c6e3 #2 [ffffc900297bb6f8] io_schedule at ffffffff81a4ca42 #3 [ffffc900297bb708] __lock_page at ffffffff811f145b #4 [ffffc900297bb798] __process_pages_contig at ffffffff814bc502 #5 [ffffc900297bb8c8] lock_delalloc_pages at ffffffff814bc684 #6 [ffffc900297bb900] find_lock_delalloc_range at ffffffff814be9ff #7 [ffffc900297bb9a0] writepage_delalloc at ffffffff814bebd0 #8 [ffffc900297bba18] __extent_writepage at ffffffff814bfbf2 #9 [ffffc900297bba98] extent_write_cache_pages at ffffffff814bffbd PID: 2167901 TASK: ffff889dc6a59c00 CPU: 14 COMMAND: "aio-dio-invalid" #0 [ffffc9003b50bb18] __schedule at ffffffff81a4c33f #1 [ffffc9003b50bba0] schedule at ffffffff81a4c6e3 #2 [ffffc9003b50bbb8] io_schedule at ffffffff81a4ca42 #3 [ffffc9003b50bbc8] wait_on_page_bit at ffffffff811f24d6 #4 [ffffc9003b50bc60] prepare_pages at ffffffff814b05a7 #5 [ffffc9003b50bcd8] btrfs_buffered_write at ffffffff814b1359 #6 [ffffc9003b50bdb0] btrfs_file_write_iter at ffffffff814b5933 #7 [ffffc9003b50be38] new_sync_write at ffffffff8128f6a8 #8 [ffffc9003b50bec8] vfs_write at ffffffff81292b9d #9 [ffffc9003b50bf00] ksys_pwrite64 at ffffffff81293032 I used drgn to find the respective pages we were stuck on page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901 page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874 As you can see the kworker is waiting for bit 0 (PG_locked) on index 7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index 8148. aio-dio-invalid has 7680, and the kworker epd looks like the following crash> struct extent_page_data ffffc900297bbbb0 struct extent_page_data { bio = 0xffff889f747ed830, tree = 0xffff889eed6ba448, extent_locked = 0, sync_io = 0 } Probably worth mentioning as well that it waits for writeback of the page to complete while holding a lock on it (at prepare_pages()). Using drgn I walked the bio pages looking for page 0xffffea00fbfc7500 which is the one we're waiting for writeback on bio = Object(prog, 'struct bio', address=0xffff889f747ed830) for i in range(0, bio.bi_vcnt.value_()): bv = bio.bi_io_vec[i] if bv.bv_page.value_() == 0xffffea00fbfc7500: print("FOUND IT") which validated what I suspected. The fix for this is simple, flush the epd before we loop back around to the beginning of the file during writeout. Fixes: b293f02 ("Btrfs: Add writepages support") CC: [email protected] # 4.4+ Reviewed-by: Filipe Manana <[email protected]> Signed-off-by: Josef Bacik <[email protected]> Signed-off-by: David Sterba <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

[ Upstream commit 5a9ef19 ] We would not be transmitting using the correct SYSTEMPORT transmit queue during ndo_select_queue() which looks up the internal TX ring map because while establishing the mapping we would be off by 4, so for instance, when we populate switch port mappings we would be doing: switch port 0, queue 0 -> ring index #0 switch port 0, queue 1 -> ring index #1 ... switch port 0, queue 3 -> ring index #3 switch port 1, queue 0 -> ring index #8 (4 + 4 * 1) ... instead of using ring index #4. This would cause our ndo_select_queue() to use the fallback queue mechanism which would pick up an incorrect ring for that switch port. Fix this by using the correct switch queue number instead of SYSTEMPORT queue number. Fixes: 25c4407 ("net: systemport: Simplify queue mapping logic") Signed-off-by: Florian Fainelli <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

[ Upstream commit 334b0f4 ] There is a race condition which results in a deadlock when rmdir and mkdir execute concurrently: $ ls /sys/fs/resctrl/c1/mon_groups/m1/ cpus cpus_list mon_data tasks Thread 1: rmdir /sys/fs/resctrl/c1 Thread 2: mkdir /sys/fs/resctrl/c1/mon_groups/m1 3 locks held by mkdir/48649: #0: (sb_writers#17){.+.+}, at: [<ffffffffb4ca2aa0>] mnt_want_write+0x20/0x50 #1: (&type->i_mutex_dir_key#8/1){+.+.}, at: [<ffffffffb4c8c13b>] filename_create+0x7b/0x170 #2: (rdtgroup_mutex){+.+.}, at: [<ffffffffb4a4389d>] rdtgroup_kn_lock_live+0x3d/0x70 4 locks held by rmdir/48652: #0: (sb_writers#17){.+.+}, at: [<ffffffffb4ca2aa0>] mnt_want_write+0x20/0x50 #1: (&type->i_mutex_dir_key#8/1){+.+.}, at: [<ffffffffb4c8c3cf>] do_rmdir+0x13f/0x1e0 #2: (&type->i_mutex_dir_key#8){++++}, at: [<ffffffffb4c86d5d>] vfs_rmdir+0x4d/0x120 #3: (rdtgroup_mutex){+.+.}, at: [<ffffffffb4a4389d>] rdtgroup_kn_lock_live+0x3d/0x70 Thread 1 is deleting control group "c1". Holding rdtgroup_mutex, kernfs_remove() removes all kernfs nodes under directory "c1" recursively, then waits for sub kernfs node "mon_groups" to drop active reference. Thread 2 is trying to create a subdirectory "m1" in the "mon_groups" directory. The wrapper kernfs_iop_mkdir() takes an active reference to the "mon_groups" directory but the code drops the active reference to the parent directory "c1" instead. As a result, Thread 1 is blocked on waiting for active reference to drop and never release rdtgroup_mutex, while Thread 2 is also blocked on trying to get rdtgroup_mutex. Thread 1 (rdtgroup_rmdir) Thread 2 (rdtgroup_mkdir) (rmdir /sys/fs/resctrl/c1) (mkdir /sys/fs/resctrl/c1/mon_groups/m1) ------------------------- ------------------------- kernfs_iop_mkdir /* * kn: "m1", parent_kn: "mon_groups", * prgrp_kn: parent_kn->parent: "c1", * * "mon_groups", parent_kn->active++: 1 */ kernfs_get_active(parent_kn) kernfs_iop_rmdir /* "c1", kn->active++ */ kernfs_get_active(kn) rdtgroup_kn_lock_live atomic_inc(&rdtgrp->waitcount) /* "c1", kn->active-- */ kernfs_break_active_protection(kn) mutex_lock rdtgroup_rmdir_ctrl free_all_child_rdtgrp sentry->flags = RDT_DELETED rdtgroup_ctrl_remove rdtgrp->flags = RDT_DELETED kernfs_get(kn) kernfs_remove(rdtgrp->kn) __kernfs_remove /* "mon_groups", sub_kn */ atomic_add(KN_DEACTIVATED_BIAS, &sub_kn->active) kernfs_drain(sub_kn) /* * sub_kn->active == KN_DEACTIVATED_BIAS + 1, * waiting on sub_kn->active to drop, but it * never drops in Thread 2 which is blocked * on getting rdtgroup_mutex. */ Thread 1 hangs here ----> wait_event(sub_kn->active == KN_DEACTIVATED_BIAS) ... rdtgroup_mkdir rdtgroup_mkdir_mon(parent_kn, prgrp_kn) mkdir_rdt_prepare(parent_kn, prgrp_kn) rdtgroup_kn_lock_live(prgrp_kn) atomic_inc(&rdtgrp->waitcount) /* * "c1", prgrp_kn->active-- * * The active reference on "c1" is * dropped, but not matching the * actual active reference taken * on "mon_groups", thus causing * Thread 1 to wait forever while * holding rdtgroup_mutex. */ kernfs_break_active_protection( prgrp_kn) /* * Trying to get rdtgroup_mutex * which is held by Thread 1. */ Thread 2 hangs here ----> mutex_lock ... The problem is that the creation of a subdirectory in the "mon_groups" directory incorrectly releases the active protection of its parent directory instead of itself before it starts waiting for rdtgroup_mutex. This is triggered by the rdtgroup_mkdir() flow calling rdtgroup_kn_lock_live()/rdtgroup_kn_unlock() with kernfs node of the parent control group ("c1") as argument. It should be called with kernfs node "mon_groups" instead. What is currently missing is that the kn->priv of "mon_groups" is NULL instead of pointing to the rdtgrp. Fix it by pointing kn->priv to rdtgrp when "mon_groups" is created. Then it could be passed to rdtgroup_kn_lock_live()/rdtgroup_kn_unlock() instead. And then it operates on the same rdtgroup structure but handles the active reference of kernfs node "mon_groups" to prevent deadlock. The same changes are also made to the "mon_data" directories. This results in some unused function parameters that will be cleaned up in follow-up patch as the focus here is on the fix only in support of backporting efforts. Fixes: c7d9aac ("x86/intel_rdt/cqm: Add mkdir support for RDT monitoring") Suggested-by: Reinette Chatre <[email protected]> Signed-off-by: Xiaochen Shen <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Reinette Chatre <[email protected]> Reviewed-by: Tony Luck <[email protected]> Acked-by: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Sasha Levin <[email protected]>

commit 1cfbb48 upstream. Confusingly, there are three SPSR layouts that a kernel may need to deal with: (1) An AArch64 SPSR_ELx view of an AArch64 pstate (2) An AArch64 SPSR_ELx view of an AArch32 pstate (3) An AArch32 SPSR_* view of an AArch32 pstate When the KVM AArch32 support code deals with SPSR_{EL2,HYP}, it's either dealing with #2 or #3 consistently. On arm64 the PSR_AA32_* definitions match the AArch64 SPSR_ELx view, and on arm the PSR_AA32_* definitions match the AArch32 SPSR_* view. However, when we inject an exception into an AArch32 guest, we have to synthesize the AArch32 SPSR_* that the guest will see. Thus, an AArch64 host needs to synthesize layout #3 from layout #2. This patch adds a new host_spsr_to_spsr32() helper for this, and makes use of it in the KVM AArch32 support code. For arm64 we need to shuffle the DIT bit around, and remove the SS bit, while for arm we can use the value as-is. I've open-coded the bit manipulation for now to avoid having to rework the existing PSR_* definitions into PSR64_AA32_* and PSR32_AA32_* definitions. I hope to perform a more thorough refactoring in future so that we can handle pstate view manipulation more consistently across the kernel tree. Signed-off-by: Mark Rutland <[email protected]> Signed-off-by: Marc Zyngier <[email protected]> Reviewed-by: Alexandru Elisei <[email protected]> Cc: [email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>

commit 42ffb0b upstream. There exists a deadlock with range_cyclic that has existed forever. If we loop around with a bio already built we could deadlock with a writer who has the page locked that we're attempting to write but is waiting on a page in our bio to be written out. The task traces are as follows PID: 1329874 TASK: ffff889ebcdf3800 CPU: 33 COMMAND: "kworker/u113:5" #0 [ffffc900297bb658] __schedule at ffffffff81a4c33f #1 [ffffc900297bb6e0] schedule at ffffffff81a4c6e3 #2 [ffffc900297bb6f8] io_schedule at ffffffff81a4ca42 #3 [ffffc900297bb708] __lock_page at ffffffff811f145b #4 [ffffc900297bb798] __process_pages_contig at ffffffff814bc502 #5 [ffffc900297bb8c8] lock_delalloc_pages at ffffffff814bc684 #6 [ffffc900297bb900] find_lock_delalloc_range at ffffffff814be9ff #7 [ffffc900297bb9a0] writepage_delalloc at ffffffff814bebd0 #8 [ffffc900297bba18] __extent_writepage at ffffffff814bfbf2 #9 [ffffc900297bba98] extent_write_cache_pages at ffffffff814bffbd PID: 2167901 TASK: ffff889dc6a59c00 CPU: 14 COMMAND: "aio-dio-invalid" #0 [ffffc9003b50bb18] __schedule at ffffffff81a4c33f #1 [ffffc9003b50bba0] schedule at ffffffff81a4c6e3 #2 [ffffc9003b50bbb8] io_schedule at ffffffff81a4ca42 #3 [ffffc9003b50bbc8] wait_on_page_bit at ffffffff811f24d6 #4 [ffffc9003b50bc60] prepare_pages at ffffffff814b05a7 #5 [ffffc9003b50bcd8] btrfs_buffered_write at ffffffff814b1359 #6 [ffffc9003b50bdb0] btrfs_file_write_iter at ffffffff814b5933 #7 [ffffc9003b50be38] new_sync_write at ffffffff8128f6a8 #8 [ffffc9003b50bec8] vfs_write at ffffffff81292b9d #9 [ffffc9003b50bf00] ksys_pwrite64 at ffffffff81293032 I used drgn to find the respective pages we were stuck on page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901 page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874 As you can see the kworker is waiting for bit 0 (PG_locked) on index 7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index 8148. aio-dio-invalid has 7680, and the kworker epd looks like the following crash> struct extent_page_data ffffc900297bbbb0 struct extent_page_data { bio = 0xffff889f747ed830, tree = 0xffff889eed6ba448, extent_locked = 0, sync_io = 0 } Probably worth mentioning as well that it waits for writeback of the page to complete while holding a lock on it (at prepare_pages()). Using drgn I walked the bio pages looking for page 0xffffea00fbfc7500 which is the one we're waiting for writeback on bio = Object(prog, 'struct bio', address=0xffff889f747ed830) for i in range(0, bio.bi_vcnt.value_()): bv = bio.bi_io_vec[i] if bv.bv_page.value_() == 0xffffea00fbfc7500: print("FOUND IT") which validated what I suspected. The fix for this is simple, flush the epd before we loop back around to the beginning of the file during writeout. Fixes: b293f02 ("Btrfs: Add writepages support") CC: [email protected] # 4.4+ Reviewed-by: Filipe Manana <[email protected]> Signed-off-by: Josef Bacik <[email protected]> Signed-off-by: David Sterba <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

commit db6a501 upstream. rcu_read_lock is needed to protect access to psock inside sock_map_unref when tearing down the map. However, we can't afford to sleep in lock_sock while in RCU read-side critical section. Grab the RCU lock only after we have locked the socket. This fixes RCU warnings triggerable on a VM with 1 vCPU when free'ing a sockmap/sockhash that contains at least one socket: | ============================= | WARNING: suspicious RCU usage | 5.5.0-04005-g8fc91b972b73 #450 Not tainted | ----------------------------- | include/linux/rcupdate.h:272 Illegal context switch in RCU read-side critical section! | | other info that might help us debug this: | | | rcu_scheduler_active = 2, debug_locks = 1 | 4 locks held by kworker/0:1/62: | #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0 | #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0 | #2: ffffffff82065d20 (rcu_read_lock){....}, at: sock_map_free+0x5/0x170 | #3: ffff8881368c5df8 (&stab->lock){+...}, at: sock_map_free+0x64/0x170 | | stack backtrace: | CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04005-g8fc91b972b73 #450 | Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014 | Workqueue: events bpf_map_free_deferred | Call Trace: | dump_stack+0x71/0xa0 | ___might_sleep+0x105/0x190 | lock_sock_nested+0x28/0x90 | sock_map_free+0x95/0x170 | bpf_map_free_deferred+0x58/0x80 | process_one_work+0x260/0x5e0 | worker_thread+0x4d/0x3e0 | kthread+0x108/0x140 | ? process_one_work+0x5e0/0x5e0 | ? kthread_park+0x90/0x90 | ret_from_fork+0x3a/0x50 | ============================= | WARNING: suspicious RCU usage | 5.5.0-04005-g8fc91b972b73-dirty #452 Not tainted | ----------------------------- | include/linux/rcupdate.h:272 Illegal context switch in RCU read-side critical section! | | other info that might help us debug this: | | | rcu_scheduler_active = 2, debug_locks = 1 | 4 locks held by kworker/0:1/62: | #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0 | #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0 | #2: ffffffff82065d20 (rcu_read_lock){....}, at: sock_hash_free+0x5/0x1d0 | #3: ffff888139966e00 (&htab->buckets[i].lock){+...}, at: sock_hash_free+0x92/0x1d0 | | stack backtrace: | CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04005-g8fc91b972b73-dirty #452 | Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014 | Workqueue: events bpf_map_free_deferred | Call Trace: | dump_stack+0x71/0xa0 | ___might_sleep+0x105/0x190 | lock_sock_nested+0x28/0x90 | sock_hash_free+0xec/0x1d0 | bpf_map_free_deferred+0x58/0x80 | process_one_work+0x260/0x5e0 | worker_thread+0x4d/0x3e0 | kthread+0x108/0x140 | ? process_one_work+0x5e0/0x5e0 | ? kthread_park+0x90/0x90 | ret_from_fork+0x3a/0x50 Fixes: 7e81a35 ("bpf: Sockmap, ensure sock lock held during tear down") Signed-off-by: Jakub Sitnicki <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: John Fastabend <[email protected]> Link: https://lore.kernel.org/bpf/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>

commit 2d5a2f9 upstream. I see the following lockdep splat in the qcom pinctrl driver when attempting to suspend the device. WARNING: possible recursive locking detected 5.4.11 #3 Tainted: G W -------------------------------------------- cat/3074 is trying to acquire lock: ffffff81f49804c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94 but task is already holding lock: ffffff81f1cc10c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&irq_desc_lock_class); lock(&irq_desc_lock_class); *** DEADLOCK *** May be due to missing lock nesting notation 6 locks held by cat/3074: #0: ffffff81f01d9420 (sb_writers#7){.+.+}, at: vfs_write+0xd0/0x1a4 #1: ffffff81bd7d2080 (&of->mutex){+.+.}, at: kernfs_fop_write+0x12c/0x1fc #2: ffffff81f4c322f0 (kn->count#337){.+.+}, at: kernfs_fop_write+0x134/0x1fc #3: ffffffe411a41d60 (system_transition_mutex){+.+.}, at: pm_suspend+0x108/0x348 #4: ffffff81f1c5e970 (&dev->mutex){....}, at: __device_suspend+0x168/0x41c #5: ffffff81f1cc10c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94 stack backtrace: CPU: 5 PID: 3074 Comm: cat Tainted: G W 5.4.11 #3 Hardware name: Google Cheza (rev3+) (DT) Call trace: dump_backtrace+0x0/0x174 show_stack+0x20/0x2c dump_stack+0xc8/0x124 __lock_acquire+0x460/0x2388 lock_acquire+0x1cc/0x210 _raw_spin_lock_irqsave+0x64/0x80 __irq_get_desc_lock+0x64/0x94 irq_set_irq_wake+0x40/0x144 qpnpint_irq_set_wake+0x28/0x34 set_irq_wake_real+0x40/0x5c irq_set_irq_wake+0x70/0x144 pm8941_pwrkey_suspend+0x34/0x44 platform_pm_suspend+0x34/0x60 dpm_run_callback+0x64/0xcc __device_suspend+0x310/0x41c dpm_suspend+0xf8/0x298 dpm_suspend_start+0x84/0xb4 suspend_devices_and_enter+0xbc/0x620 pm_suspend+0x210/0x348 state_store+0xb0/0x108 kobj_attr_store+0x14/0x24 sysfs_kf_write+0x4c/0x64 kernfs_fop_write+0x15c/0x1fc __vfs_write+0x54/0x18c vfs_write+0xe4/0x1a4 ksys_write+0x7c/0xe4 __arm64_sys_write+0x20/0x2c el0_svc_common+0xa8/0x160 el0_svc_handler+0x7c/0x98 el0_svc+0x8/0xc Set a lockdep class when we map the irq so that irq_set_wake() doesn't warn about a lockdep bug that doesn't exist. Fixes: 12a9eea ("spmi: pmic-arb: convert to v2 irq interfaces to support hierarchical IRQ chips") Cc: Douglas Anderson <[email protected]> Cc: Brian Masney <[email protected]> Cc: Lina Iyer <[email protected]> Cc: Maulik Shah <[email protected]> Cc: Bjorn Andersson <[email protected]> Signed-off-by: Stephen Boyd <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Linus Walleij <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

[ Upstream commit 1b710b1 ] Sergey didn't like the locking order, uart_port->lock -> tty_port->lock uart_write (uart_port->lock) __uart_start pl011_start_tx pl011_tx_chars uart_write_wakeup tty_port_tty_wakeup tty_port_default tty_port_tty_get (tty_port->lock) but those code is so old, and I have no clue how to de-couple it after checking other locks in the splat. There is an onging effort to make all printk() as deferred, so until that happens, workaround it for now as a short-term fix. LTP: starting iogen01 (export LTPROOT; rwtest -N iogen01 -i 120s -s read,write -Da -Dv -n 2 500b:$TMPDIR/doio.f1.$$ 1000b:$TMPDIR/doio.f2.$$) WARNING: possible circular locking dependency detected ------------------------------------------------------ doio/49441 is trying to acquire lock: ffff008b7cff7290 (&(&zone->lock)->rlock){..-.}, at: rmqueue+0x138/0x2050 but task is already holding lock: 60ff000822352818 (&pool->lock/1){-.-.}, at: start_flush_work+0xd8/0x3f0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&pool->lock/1){-.-.}: lock_acquire+0x320/0x360 _raw_spin_lock+0x64/0x80 __queue_work+0x4b4/0xa10 queue_work_on+0xac/0x11c tty_schedule_flip+0x84/0xbc tty_flip_buffer_push+0x1c/0x28 pty_write+0x98/0xd0 n_tty_write+0x450/0x60c tty_write+0x338/0x474 __vfs_write+0x88/0x214 vfs_write+0x12c/0x1a4 redirected_tty_write+0x90/0xdc do_loop_readv_writev+0x140/0x180 do_iter_write+0xe0/0x10c vfs_writev+0x134/0x1cc do_writev+0xbc/0x130 __arm64_sys_writev+0x58/0x8c el0_svc_handler+0x170/0x240 el0_sync_handler+0x150/0x250 el0_sync+0x164/0x180 -> #3 (&(&port->lock)->rlock){-.-.}: lock_acquire+0x320/0x360 _raw_spin_lock_irqsave+0x7c/0x9c tty_port_tty_get+0x24/0x60 tty_port_default_wakeup+0x1c/0x3c tty_port_tty_wakeup+0x34/0x40 uart_write_wakeup+0x28/0x44 pl011_tx_chars+0x1b8/0x270 pl011_start_tx+0x24/0x70 __uart_start+0x5c/0x68 uart_write+0x164/0x1c8 do_output_char+0x33c/0x348 n_tty_write+0x4bc/0x60c tty_write+0x338/0x474 redirected_tty_write+0xc0/0xdc do_loop_readv_writev+0x140/0x180 do_iter_write+0xe0/0x10c vfs_writev+0x134/0x1cc do_writev+0xbc/0x130 __arm64_sys_writev+0x58/0x8c el0_svc_handler+0x170/0x240 el0_sync_handler+0x150/0x250 el0_sync+0x164/0x180 -> #2 (&port_lock_key){-.-.}: lock_acquire+0x320/0x360 _raw_spin_lock+0x64/0x80 pl011_console_write+0xec/0x2cc console_unlock+0x794/0x96c vprintk_emit+0x260/0x31c vprintk_default+0x54/0x7c vprintk_func+0x218/0x254 printk+0x7c/0xa4 register_console+0x734/0x7b0 uart_add_one_port+0x734/0x834 pl011_register_port+0x6c/0xac sbsa_uart_probe+0x234/0x2ec platform_drv_probe+0xd4/0x124 really_probe+0x250/0x71c driver_probe_device+0xb4/0x200 __device_attach_driver+0xd8/0x188 bus_for_each_drv+0xbc/0x110 __device_attach+0x120/0x220 device_initial_probe+0x20/0x2c bus_probe_device+0x54/0x100 device_add+0xae8/0xc2c platform_device_add+0x278/0x3b8 platform_device_register_full+0x238/0x2ac acpi_create_platform_device+0x2dc/0x3a8 acpi_bus_attach+0x390/0x3cc acpi_bus_attach+0x108/0x3cc acpi_bus_attach+0x108/0x3cc acpi_bus_attach+0x108/0x3cc acpi_bus_scan+0x7c/0xb0 acpi_scan_init+0xe4/0x304 acpi_init+0x100/0x114 do_one_initcall+0x348/0x6a0 do_initcall_level+0x190/0x1fc do_basic_setup+0x34/0x4c kernel_init_freeable+0x19c/0x260 kernel_init+0x18/0x338 ret_from_fork+0x10/0x18 -> #1 (console_owner){-...}: lock_acquire+0x320/0x360 console_lock_spinning_enable+0x6c/0x7c console_unlock+0x4f8/0x96c vprintk_emit+0x260/0x31c vprintk_default+0x54/0x7c vprintk_func+0x218/0x254 printk+0x7c/0xa4 get_random_u64+0x1c4/0x1dc shuffle_pick_tail+0x40/0xac __free_one_page+0x424/0x710 free_one_page+0x70/0x120 __free_pages_ok+0x61c/0xa94 __free_pages_core+0x1bc/0x294 memblock_free_pages+0x38/0x48 __free_pages_memory+0xcc/0xfc __free_memory_core+0x70/0x78 free_low_memory_core_early+0x148/0x18c memblock_free_all+0x18/0x54 mem_init+0xb4/0x17c mm_init+0x14/0x38 start_kernel+0x19c/0x530 -> #0 (&(&zone->lock)->rlock){..-.}: validate_chain+0xf6c/0x2e2c __lock_acquire+0x868/0xc2c lock_acquire+0x320/0x360 _raw_spin_lock+0x64/0x80 rmqueue+0x138/0x2050 get_page_from_freelist+0x474/0x688 __alloc_pages_nodemask+0x3b4/0x18dc alloc_pages_current+0xd0/0xe0 alloc_slab_page+0x2b4/0x5e0 new_slab+0xc8/0x6bc ___slab_alloc+0x3b8/0x640 kmem_cache_alloc+0x4b4/0x588 __debug_object_init+0x778/0x8b4 debug_object_init_on_stack+0x40/0x50 start_flush_work+0x16c/0x3f0 __flush_work+0xb8/0x124 flush_work+0x20/0x30 xlog_cil_force_lsn+0x88/0x204 [xfs] xfs_log_force_lsn+0x128/0x1b8 [xfs] xfs_file_fsync+0x3c4/0x488 [xfs] vfs_fsync_range+0xb0/0xd0 generic_write_sync+0x80/0xa0 [xfs] xfs_file_buffered_aio_write+0x66c/0x6e4 [xfs] xfs_file_write_iter+0x1a0/0x218 [xfs] __vfs_write+0x1cc/0x214 vfs_write+0x12c/0x1a4 ksys_write+0xb0/0x120 __arm64_sys_write+0x54/0x88 el0_svc_handler+0x170/0x240 el0_sync_handler+0x150/0x250 el0_sync+0x164/0x180 other info that might help us debug this: Chain exists of: &(&zone->lock)->rlock --> &(&port->lock)->rlock --> &pool->lock/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pool->lock/1); lock(&(&port->lock)->rlock); lock(&pool->lock/1); lock(&(&zone->lock)->rlock); *** DEADLOCK *** 4 locks held by doio/49441: #0: a0ff00886fc27408 (sb_writers#8){.+.+}, at: vfs_write+0x118/0x1a4 #1: 8fff00080810dfe0 (&xfs_nondir_ilock_class){++++}, at: xfs_ilock+0x2a8/0x300 [xfs] #2: ffff9000129f2390 (rcu_read_lock){....}, at: rcu_lock_acquire+0x8/0x38 #3: 60ff000822352818 (&pool->lock/1){-.-.}, at: start_flush_work+0xd8/0x3f0 stack backtrace: CPU: 48 PID: 49441 Comm: doio Tainted: G W Hardware name: HPE Apollo 70 /C01_APACHE_MB , BIOS L50_5.13_1.11 06/18/2019 Call trace: dump_backtrace+0x0/0x248 show_stack+0x20/0x2c dump_stack+0xe8/0x150 print_circular_bug+0x368/0x380 check_noncircular+0x28c/0x294 validate_chain+0xf6c/0x2e2c __lock_acquire+0x868/0xc2c lock_acquire+0x320/0x360 _raw_spin_lock+0x64/0x80 rmqueue+0x138/0x2050 get_page_from_freelist+0x474/0x688 __alloc_pages_nodemask+0x3b4/0x18dc alloc_pages_current+0xd0/0xe0 alloc_slab_page+0x2b4/0x5e0 new_slab+0xc8/0x6bc ___slab_alloc+0x3b8/0x640 kmem_cache_alloc+0x4b4/0x588 __debug_object_init+0x778/0x8b4 debug_object_init_on_stack+0x40/0x50 start_flush_work+0x16c/0x3f0 __flush_work+0xb8/0x124 flush_work+0x20/0x30 xlog_cil_force_lsn+0x88/0x204 [xfs] xfs_log_force_lsn+0x128/0x1b8 [xfs] xfs_file_fsync+0x3c4/0x488 [xfs] vfs_fsync_range+0xb0/0xd0 generic_write_sync+0x80/0xa0 [xfs] xfs_file_buffered_aio_write+0x66c/0x6e4 [xfs] xfs_file_write_iter+0x1a0/0x218 [xfs] __vfs_write+0x1cc/0x214 vfs_write+0x12c/0x1a4 ksys_write+0xb0/0x120 __arm64_sys_write+0x54/0x88 el0_svc_handler+0x170/0x240 el0_sync_handler+0x150/0x250 el0_sync+0x164/0x180 Reviewed-by: Sergey Senozhatsky <[email protected]> Signed-off-by: Qian Cai <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Theodore Ts'o <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

[ Upstream commit 576c75e ] With zpci_disable() working, lockdep detected a potential deadlock (lockdep output at the end). The deadlock is between recovering a PCI function via the /sys/bus/pci/devices/<dev>/recover attribute vs powering it off via /sys/bus/pci/slots/<slot>/power. The fix is analogous to the changes in commit 0ee223b ("scsi: core: Avoid that SCSI device removal through sysfs triggers a deadlock") that fixed a potential deadlock on removing a SCSI device via sysfs. [ 204.830107] ====================================================== [ 204.830109] WARNING: possible circular locking dependency detected [ 204.830111] 5.5.0-rc2-06072-gbc03ecc9a672 #6 Tainted: G W [ 204.830112] ------------------------------------------------------ [ 204.830113] bash/1034 is trying to acquire lock: [ 204.830115] 0000000192a1a610 (kn->count#200){++++}, at: kernfs_remove_by_name_ns+0x5c/0xa8 [ 204.830122] but task is already holding lock: [ 204.830123] 00000000c16134a8 (pci_rescan_remove_lock){+.+.}, at: pci_stop_and_remove_bus_device_locked+0x26/0x48 [ 204.830128] which lock already depends on the new lock. [ 204.830129] the existing dependency chain (in reverse order) is: [ 204.830130] -> #1 (pci_rescan_remove_lock){+.+.}: [ 204.830134] validate_chain+0x93a/0xd08 [ 204.830136] __lock_acquire+0x4ae/0x9d0 [ 204.830137] lock_acquire+0x114/0x280 [ 204.830140] __mutex_lock+0xa2/0x960 [ 204.830142] mutex_lock_nested+0x32/0x40 [ 204.830145] recover_store+0x4c/0xa8 [ 204.830147] kernfs_fop_write+0xe6/0x218 [ 204.830151] vfs_write+0xb0/0x1b8 [ 204.830152] ksys_write+0x6c/0xf8 [ 204.830154] system_call+0xd8/0x2d8 [ 204.830155] -> #0 (kn->count#200){++++}: [ 204.830187] check_noncircular+0x1e6/0x240 [ 204.830189] check_prev_add+0xfc/0xdb0 [ 204.830190] validate_chain+0x93a/0xd08 [ 204.830192] __lock_acquire+0x4ae/0x9d0 [ 204.830193] lock_acquire+0x114/0x280 [ 204.830194] __kernfs_remove.part.0+0x2e4/0x360 [ 204.830196] kernfs_remove_by_name_ns+0x5c/0xa8 [ 204.830198] remove_files.isra.0+0x4c/0x98 [ 204.830199] sysfs_remove_group+0x66/0xc8 [ 204.830201] sysfs_remove_groups+0x46/0x68 [ 204.830204] device_remove_attrs+0x52/0x90 [ 204.830207] device_del+0x182/0x418 [ 204.830208] pci_remove_bus_device+0x8a/0x130 [ 204.830210] pci_stop_and_remove_bus_device_locked+0x3a/0x48 [ 204.830212] disable_slot+0x68/0x100 [ 204.830213] power_write_file+0x7c/0x130 [ 204.830215] kernfs_fop_write+0xe6/0x218 [ 204.830217] vfs_write+0xb0/0x1b8 [ 204.830218] ksys_write+0x6c/0xf8 [ 204.830220] system_call+0xd8/0x2d8 [ 204.830221] other info that might help us debug this: [ 204.830223] Possible unsafe locking scenario: [ 204.830224] CPU0 CPU1 [ 204.830225] ---- ---- [ 204.830226] lock(pci_rescan_remove_lock); [ 204.830227] lock(kn->count#200); [ 204.830229] lock(pci_rescan_remove_lock); [ 204.830231] lock(kn->count#200); [ 204.830233] *** DEADLOCK *** [ 204.830234] 4 locks held by bash/1034: [ 204.830235] #0: 00000001b6fbc498 (sb_writers#4){.+.+}, at: vfs_write+0x158/0x1b8 [ 204.830239] #1: 000000018c9f5090 (&of->mutex){+.+.}, at: kernfs_fop_write+0xaa/0x218 [ 204.830242] #2: 00000001f7da0810 (kn->count#235){.+.+}, at: kernfs_fop_write+0xb6/0x218 [ 204.830245] #3: 00000000c16134a8 (pci_rescan_remove_lock){+.+.}, at: pci_stop_and_remove_bus_device_locked+0x26/0x48 [ 204.830248] stack backtrace: [ 204.830250] CPU: 2 PID: 1034 Comm: bash Tainted: G W 5.5.0-rc2-06072-gbc03ecc9a672 #6 [ 204.830252] Hardware name: IBM 8561 T01 703 (LPAR) [ 204.830253] Call Trace: [ 204.830257] [<00000000c05e10c0>] show_stack+0x88/0xf0 [ 204.830260] [<00000000c112dca4>] dump_stack+0xa4/0xe0 [ 204.830261] [<00000000c0694c06>] check_noncircular+0x1e6/0x240 [ 204.830263] [<00000000c0695bec>] check_prev_add+0xfc/0xdb0 [ 204.830264] [<00000000c06971da>] validate_chain+0x93a/0xd08 [ 204.830266] [<00000000c06994c6>] __lock_acquire+0x4ae/0x9d0 [ 204.830267] [<00000000c069867c>] lock_acquire+0x114/0x280 [ 204.830269] [<00000000c09ca15c>] __kernfs_remove.part.0+0x2e4/0x360 [ 204.830270] [<00000000c09cb5c4>] kernfs_remove_by_name_ns+0x5c/0xa8 [ 204.830272] [<00000000c09cee14>] remove_files.isra.0+0x4c/0x98 [ 204.830274] [<00000000c09cf2ae>] sysfs_remove_group+0x66/0xc8 [ 204.830276] [<00000000c09cf356>] sysfs_remove_groups+0x46/0x68 [ 204.830278] [<00000000c0e3dfe2>] device_remove_attrs+0x52/0x90 [ 204.830280] [<00000000c0e40382>] device_del+0x182/0x418 [ 204.830281] [<00000000c0dcfd7a>] pci_remove_bus_device+0x8a/0x130 [ 204.830283] [<00000000c0dcfe92>] pci_stop_and_remove_bus_device_locked+0x3a/0x48 [ 204.830285] [<00000000c0de7190>] disable_slot+0x68/0x100 [ 204.830286] [<00000000c0de6514>] power_write_file+0x7c/0x130 [ 204.830288] [<00000000c09cc846>] kernfs_fop_write+0xe6/0x218 [ 204.830290] [<00000000c08f3480>] vfs_write+0xb0/0x1b8 [ 204.830291] [<00000000c08f378c>] ksys_write+0x6c/0xf8 [ 204.830293] [<00000000c1154374>] system_call+0xd8/0x2d8 [ 204.830294] INFO: lockdep is turned off. Signed-off-by: Niklas Schnelle <[email protected]> Reviewed-by: Peter Oberparleiter <[email protected]> Signed-off-by: Vasily Gorbik <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

[ Upstream commit c34f6dc ] I see the following lockdep splat in the qcom pinctrl driver when attempting to suspend the device. ============================================ WARNING: possible recursive locking detected 5.4.2 #2 Tainted: G S -------------------------------------------- cat/6536 is trying to acquire lock: ffffff814787ccc0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94 but task is already holding lock: ffffff81436740c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&irq_desc_lock_class); lock(&irq_desc_lock_class); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by cat/6536: #0: ffffff8140e0c420 (sb_writers#7){.+.+}, at: vfs_write+0xc8/0x19c #1: ffffff8121eec480 (&of->mutex){+.+.}, at: kernfs_fop_write+0x128/0x1f4 #2: ffffff8147cad668 (kn->count#263){.+.+}, at: kernfs_fop_write+0x130/0x1f4 #3: ffffffd011446000 (system_transition_mutex){+.+.}, at: pm_suspend+0x108/0x354 #4: ffffff814302b970 (&dev->mutex){....}, at: __device_suspend+0x16c/0x420 #5: ffffff81436740c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94 #6: ffffff81479b8c10 (&pctrl->lock){....}, at: msm_gpio_irq_set_wake+0x48/0x7c stack backtrace: CPU: 4 PID: 6536 Comm: cat Tainted: G S 5.4.2 #2 Call trace: dump_backtrace+0x0/0x174 show_stack+0x20/0x2c dump_stack+0xdc/0x144 __lock_acquire+0x52c/0x2268 lock_acquire+0x1dc/0x220 _raw_spin_lock_irqsave+0x64/0x80 __irq_get_desc_lock+0x64/0x94 irq_set_irq_wake+0x40/0x144 msm_gpio_irq_set_wake+0x5c/0x7c set_irq_wake_real+0x40/0x5c irq_set_irq_wake+0x70/0x144 cros_ec_rtc_suspend+0x38/0x4c platform_pm_suspend+0x34/0x60 dpm_run_callback+0x64/0xcc __device_suspend+0x314/0x420 dpm_suspend+0xf8/0x298 dpm_suspend_start+0x84/0xb4 suspend_devices_and_enter+0xbc/0x628 pm_suspend+0x214/0x354 state_store+0xb0/0x108 kobj_attr_store+0x14/0x24 sysfs_kf_write+0x4c/0x64 kernfs_fop_write+0x158/0x1f4 __vfs_write+0x54/0x18c vfs_write+0xdc/0x19c ksys_write+0x7c/0xe4 __arm64_sys_write+0x20/0x2c el0_svc_common+0xa8/0x160 el0_svc_compat_handler+0x2c/0x38 el0_svc_compat+0x8/0x10 This is because the msm_gpio_irq_set_wake() function calls irq_set_irq_wake() as a backup in case the irq comes in during the path to idle. Given that we're calling irqchip functions from within an irqchip we need to set the lockdep class to be different for this child controller vs. the default one that the parent irqchip gets. This used to be done before this driver was converted to hierarchical irq domains in commit e35a6ae ("pinctrl/msm: Setup GPIO chip in hierarchy") via the gpiochip_irq_map() function. With hierarchical irq domains this function has been replaced by gpiochip_hierarchy_irq_domain_alloc(). Therefore, set the lockdep class like was done previously in the irq domain path so we can avoid this lockdep warning. Fixes: fdd61a0 ("gpio: Add support for hierarchical IRQ domains") Cc: Thierry Reding <[email protected]> Cc: Brian Masney <[email protected]> Cc: Lina Iyer <[email protected]> Cc: Marc Zyngier <[email protected]> Cc: Maulik Shah <[email protected]> Signed-off-by: Stephen Boyd <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Linus Walleij <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

commit 52e29e3 upstream. The only time we actually leave the path spinning is if we're truncating a small amount and don't actually free an extent, which is not a common occurrence. We have to set the path blocking in order to add the delayed ref anyway, so the first extent we find we set the path to blocking and stay blocking for the duration of the operation. With the upcoming file extent map stuff there will be another case that we have to have the path blocking, so just swap to blocking always. Note: this patch also fixes a warning after 28553fa ("Btrfs: fix race between shrinking truncate and fiemap") got merged that inserts extent locks around truncation so the path must not leave spinning locks after btrfs_search_slot. [70.794783] BUG: sleeping function called from invalid context at mm/slab.h:565 [70.794834] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1141, name: rsync [70.794863] 5 locks held by rsync/1141: [70.794876] #0: ffff888417b9c408 (sb_writers#17){.+.+}, at: mnt_want_write+0x20/0x50 [70.795030] #1: ffff888428de28e8 (&type->i_mutex_dir_key#13/1){+.+.}, at: lock_rename+0xf1/0x100 [70.795051] #2: ffff888417b9c608 (sb_internal#2){.+.+}, at: start_transaction+0x394/0x560 [70.795124] #3: ffff888403081768 (btrfs-fs-01){++++}, at: btrfs_try_tree_write_lock+0x2f/0x160 [70.795203] #4: ffff888403086568 (btrfs-fs-00){++++}, at: btrfs_try_tree_write_lock+0x2f/0x160 [70.795222] CPU: 5 PID: 1141 Comm: rsync Not tainted 5.6.0-rc2-backup+ #2 [70.795362] Call Trace: [70.795374] dump_stack+0x71/0xa0 [70.795445] ___might_sleep.part.96.cold.106+0xa6/0xb6 [70.795459] kmem_cache_alloc+0x1d3/0x290 [70.795471] alloc_extent_state+0x22/0x1c0 [70.795544] __clear_extent_bit+0x3ba/0x580 [70.795557] ? _raw_spin_unlock_irq+0x24/0x30 [70.795569] btrfs_truncate_inode_items+0x339/0xe50 [70.795647] btrfs_evict_inode+0x269/0x540 [70.795659] ? dput.part.38+0x29/0x460 [70.795671] evict+0xcd/0x190 [70.795682] __dentry_kill+0xd6/0x180 [70.795754] dput.part.38+0x2ad/0x460 [70.795765] do_renameat2+0x3cb/0x540 [70.795777] __x64_sys_rename+0x1c/0x20 Reported-by: Dave Jones <[email protected]> Fixes: 28553fa ("Btrfs: fix race between shrinking truncate and fiemap") CC: [email protected] # 4.4+ Reviewed-by: Filipe Manana <[email protected]> Signed-off-by: Josef Bacik <[email protected]> Reviewed-by: David Sterba <[email protected]> [ add note ] Signed-off-by: David Sterba <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

[ Upstream commit 064ff66 ] After bond_release(), netdev_update_lockdep_key() should be called. But both ioctl path and attribute path don't call netdev_update_lockdep_key(). This patch adds missing netdev_update_lockdep_key(). Test commands: ip link add bond0 type bond ip link add bond1 type bond ifenslave bond0 bond1 ifenslave -d bond0 bond1 ifenslave bond1 bond0 Splat looks like: [ 29.501182][ T1046] WARNING: possible circular locking dependency detected [ 29.501945][ T1039] hardirqs last disabled at (1962): [<ffffffffac6c807f>] handle_mm_fault+0x13f/0x700 [ 29.503442][ T1046] 5.5.0+ #322 Not tainted [ 29.503447][ T1046] ------------------------------------------------------ [ 29.504277][ T1039] softirqs last enabled at (1180): [<ffffffffade00678>] __do_softirq+0x678/0x981 [ 29.505443][ T1046] ifenslave/1046 is trying to acquire lock: [ 29.505886][ T1039] softirqs last disabled at (1169): [<ffffffffac19c18a>] irq_exit+0x17a/0x1a0 [ 29.509997][ T1046] ffff88805d5da280 (&dev->addr_list_lock_key#3){+...}, at: dev_mc_sync_multiple+0x95/0x120 [ 29.511243][ T1046] [ 29.511243][ T1046] but task is already holding lock: [ 29.512192][ T1046] ffff8880460f2280 (&dev->addr_list_lock_key#4){+...}, at: bond_enslave+0x4482/0x47b0 [bonding] [ 29.514124][ T1046] [ 29.514124][ T1046] which lock already depends on the new lock. [ 29.514124][ T1046] [ 29.517297][ T1046] [ 29.517297][ T1046] the existing dependency chain (in reverse order) is: [ 29.518231][ T1046] [ 29.518231][ T1046] -> #1 (&dev->addr_list_lock_key#4){+...}: [ 29.519076][ T1046] _raw_spin_lock+0x30/0x70 [ 29.519588][ T1046] dev_mc_sync_multiple+0x95/0x120 [ 29.520208][ T1046] bond_enslave+0x448d/0x47b0 [bonding] [ 29.520862][ T1046] bond_option_slaves_set+0x1a3/0x370 [bonding] [ 29.521640][ T1046] __bond_opt_set+0x1ff/0xbb0 [bonding] [ 29.522438][ T1046] __bond_opt_set_notify+0x2b/0xf0 [bonding] [ 29.523251][ T1046] bond_opt_tryset_rtnl+0x92/0xf0 [bonding] [ 29.524082][ T1046] bonding_sysfs_store_option+0x8a/0xf0 [bonding] [ 29.524959][ T1046] kernfs_fop_write+0x276/0x410 [ 29.525620][ T1046] vfs_write+0x197/0x4a0 [ 29.526218][ T1046] ksys_write+0x141/0x1d0 [ 29.526818][ T1046] do_syscall_64+0x99/0x4f0 [ 29.527430][ T1046] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 29.528265][ T1046] [ 29.528265][ T1046] -> #0 (&dev->addr_list_lock_key#3){+...}: [ 29.529272][ T1046] __lock_acquire+0x2d8d/0x3de0 [ 29.529935][ T1046] lock_acquire+0x164/0x3b0 [ 29.530638][ T1046] _raw_spin_lock+0x30/0x70 [ 29.531187][ T1046] dev_mc_sync_multiple+0x95/0x120 [ 29.531790][ T1046] bond_enslave+0x448d/0x47b0 [bonding] [ 29.532451][ T1046] bond_option_slaves_set+0x1a3/0x370 [bonding] [ 29.533163][ T1046] __bond_opt_set+0x1ff/0xbb0 [bonding] [ 29.533789][ T1046] __bond_opt_set_notify+0x2b/0xf0 [bonding] [ 29.534595][ T1046] bond_opt_tryset_rtnl+0x92/0xf0 [bonding] [ 29.535500][ T1046] bonding_sysfs_store_option+0x8a/0xf0 [bonding] [ 29.536379][ T1046] kernfs_fop_write+0x276/0x410 [ 29.537057][ T1046] vfs_write+0x197/0x4a0 [ 29.537640][ T1046] ksys_write+0x141/0x1d0 [ 29.538251][ T1046] do_syscall_64+0x99/0x4f0 [ 29.538870][ T1046] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 29.539659][ T1046] [ 29.539659][ T1046] other info that might help us debug this: [ 29.539659][ T1046] [ 29.540953][ T1046] Possible unsafe locking scenario: [ 29.540953][ T1046] [ 29.541883][ T1046] CPU0 CPU1 [ 29.542540][ T1046] ---- ---- [ 29.543209][ T1046] lock(&dev->addr_list_lock_key#4); [ 29.543880][ T1046] lock(&dev->addr_list_lock_key#3); [ 29.544873][ T1046] lock(&dev->addr_list_lock_key#4); [ 29.545863][ T1046] lock(&dev->addr_list_lock_key#3); [ 29.546525][ T1046] [ 29.546525][ T1046] *** DEADLOCK *** [ 29.546525][ T1046] [ 29.547542][ T1046] 5 locks held by ifenslave/1046: [ 29.548196][ T1046] #0: ffff88806044c478 (sb_writers#5){.+.+}, at: vfs_write+0x3bb/0x4a0 [ 29.549248][ T1046] #1: ffff88805af00890 (&of->mutex){+.+.}, at: kernfs_fop_write+0x1cf/0x410 [ 29.550343][ T1046] #2: ffff88805b8b54b0 (kn->count#157){.+.+}, at: kernfs_fop_write+0x1f2/0x410 [ 29.551575][ T1046] #3: ffffffffaecf4cf0 (rtnl_mutex){+.+.}, at: bond_opt_tryset_rtnl+0x5f/0xf0 [bonding] [ 29.552819][ T1046] #4: ffff8880460f2280 (&dev->addr_list_lock_key#4){+...}, at: bond_enslave+0x4482/0x47b0 [bonding] [ 29.554175][ T1046] [ 29.554175][ T1046] stack backtrace: [ 29.554907][ T1046] CPU: 0 PID: 1046 Comm: ifenslave Not tainted 5.5.0+ #322 [ 29.555854][ T1046] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 29.557064][ T1046] Call Trace: [ 29.557504][ T1046] dump_stack+0x96/0xdb [ 29.558054][ T1046] check_noncircular+0x371/0x450 [ 29.558723][ T1046] ? print_circular_bug.isra.35+0x310/0x310 [ 29.559486][ T1046] ? hlock_class+0x130/0x130 [ 29.560100][ T1046] ? __lock_acquire+0x2d8d/0x3de0 [ 29.560761][ T1046] __lock_acquire+0x2d8d/0x3de0 [ 29.561366][ T1046] ? register_lock_class+0x14d0/0x14d0 [ 29.562045][ T1046] ? find_held_lock+0x39/0x1d0 [ 29.562641][ T1046] lock_acquire+0x164/0x3b0 [ 29.563199][ T1046] ? dev_mc_sync_multiple+0x95/0x120 [ 29.563872][ T1046] _raw_spin_lock+0x30/0x70 [ 29.564464][ T1046] ? dev_mc_sync_multiple+0x95/0x120 [ 29.565146][ T1046] dev_mc_sync_multiple+0x95/0x120 [ 29.565793][ T1046] bond_enslave+0x448d/0x47b0 [bonding] [ 29.566487][ T1046] ? bond_update_slave_arr+0x940/0x940 [bonding] [ 29.567279][ T1046] ? bstr_printf+0xc20/0xc20 [ 29.567857][ T1046] ? stack_trace_consume_entry+0x160/0x160 [ 29.568614][ T1046] ? deactivate_slab.isra.77+0x2c5/0x800 [ 29.569320][ T1046] ? check_chain_key+0x236/0x5d0 [ 29.569939][ T1046] ? sscanf+0x93/0xc0 [ 29.570442][ T1046] ? vsscanf+0x1e20/0x1e20 [ 29.571003][ T1046] bond_option_slaves_set+0x1a3/0x370 [bonding] [ ... ] Fixes: ab92d68 ("net: core: add generic lockdep keys") Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

[ Upstream commit 102210f ] rmnet_get_port() internally calls rcu_dereference_rtnl(), which checks RTNL. But rmnet_get_port() could be called by packet path. The packet path is not protected by RTNL. So, the suspicious RCU usage problem occurs. Test commands: modprobe rmnet ip netns add nst ip link add veth0 type veth peer name veth1 ip link set veth1 netns nst ip link add rmnet0 link veth0 type rmnet mux_id 1 ip netns exec nst ip link add rmnet1 link veth1 type rmnet mux_id 1 ip netns exec nst ip link set veth1 up ip netns exec nst ip link set rmnet1 up ip netns exec nst ip a a 192.168.100.2/24 dev rmnet1 ip link set veth0 up ip link set rmnet0 up ip a a 192.168.100.1/24 dev rmnet0 ping 192.168.100.2 Splat looks like: [ 146.630958][ T1174] WARNING: suspicious RCU usage [ 146.631735][ T1174] 5.6.0-rc1+ #447 Not tainted [ 146.632387][ T1174] ----------------------------- [ 146.633151][ T1174] drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c:386 suspicious rcu_dereference_check() ! [ 146.634742][ T1174] [ 146.634742][ T1174] other info that might help us debug this: [ 146.634742][ T1174] [ 146.645992][ T1174] [ 146.645992][ T1174] rcu_scheduler_active = 2, debug_locks = 1 [ 146.646937][ T1174] 5 locks held by ping/1174: [ 146.647609][ T1174] #0: ffff8880c31dea70 (sk_lock-AF_INET){+.+.}, at: raw_sendmsg+0xab8/0x2980 [ 146.662463][ T1174] #1: ffffffff93925660 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x243/0x2150 [ 146.671696][ T1174] #2: ffffffff93925660 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x213/0x2940 [ 146.673064][ T1174] #3: ffff8880c19ecd58 (&dev->qdisc_running_key#7){+...}, at: ip_finish_output2+0x714/0x2150 [ 146.690358][ T1174] #4: ffff8880c5796898 (&dev->qdisc_xmit_lock_key#3){+.-.}, at: sch_direct_xmit+0x1e2/0x1020 [ 146.699875][ T1174] [ 146.699875][ T1174] stack backtrace: [ 146.701091][ T1174] CPU: 0 PID: 1174 Comm: ping Not tainted 5.6.0-rc1+ #447 [ 146.705215][ T1174] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 146.706565][ T1174] Call Trace: [ 146.707102][ T1174] dump_stack+0x96/0xdb [ 146.708007][ T1174] rmnet_get_port.part.9+0x76/0x80 [rmnet] [ 146.709233][ T1174] rmnet_egress_handler+0x107/0x420 [rmnet] [ 146.710492][ T1174] ? sch_direct_xmit+0x1e2/0x1020 [ 146.716193][ T1174] rmnet_vnd_start_xmit+0x3d/0xa0 [rmnet] [ 146.717012][ T1174] dev_hard_start_xmit+0x160/0x740 [ 146.717854][ T1174] sch_direct_xmit+0x265/0x1020 [ 146.718577][ T1174] ? register_lock_class+0x14d0/0x14d0 [ 146.719429][ T1174] ? dev_watchdog+0xac0/0xac0 [ 146.723738][ T1174] ? __dev_queue_xmit+0x15fd/0x2940 [ 146.724469][ T1174] ? lock_acquire+0x164/0x3b0 [ 146.725172][ T1174] __dev_queue_xmit+0x20c7/0x2940 [ ... ] Fixes: ceed73a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation") Signed-off-by: Taehee Yoo <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

[ Upstream commit 6c5d911 ] journal_head::b_transaction and journal_head::b_next_transaction could be accessed concurrently as noticed by KCSAN, LTP: starting fsync04 /dev/zero: Can't open blockdev EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null) ================================================================== BUG: KCSAN: data-race in __jbd2_journal_refile_buffer [jbd2] / jbd2_write_access_granted [jbd2] write to 0xffff99f9b1bd0e30 of 8 bytes by task 25721 on cpu 70: __jbd2_journal_refile_buffer+0xdd/0x210 [jbd2] __jbd2_journal_refile_buffer at fs/jbd2/transaction.c:2569 jbd2_journal_commit_transaction+0x2d15/0x3f20 [jbd2] (inlined by) jbd2_journal_commit_transaction at fs/jbd2/commit.c:1034 kjournald2+0x13b/0x450 [jbd2] kthread+0x1cd/0x1f0 ret_from_fork+0x27/0x50 read to 0xffff99f9b1bd0e30 of 8 bytes by task 25724 on cpu 68: jbd2_write_access_granted+0x1b2/0x250 [jbd2] jbd2_write_access_granted at fs/jbd2/transaction.c:1155 jbd2_journal_get_write_access+0x2c/0x60 [jbd2] __ext4_journal_get_write_access+0x50/0x90 [ext4] ext4_mb_mark_diskspace_used+0x158/0x620 [ext4] ext4_mb_new_blocks+0x54f/0xca0 [ext4] ext4_ind_map_blocks+0xc79/0x1b40 [ext4] ext4_map_blocks+0x3b4/0x950 [ext4] _ext4_get_block+0xfc/0x270 [ext4] ext4_get_block+0x3b/0x50 [ext4] __block_write_begin_int+0x22e/0xae0 __block_write_begin+0x39/0x50 ext4_write_begin+0x388/0xb50 [ext4] generic_perform_write+0x15d/0x290 ext4_buffered_write_iter+0x11f/0x210 [ext4] ext4_file_write_iter+0xce/0x9e0 [ext4] new_sync_write+0x29c/0x3b0 __vfs_write+0x92/0xa0 vfs_write+0x103/0x260 ksys_write+0x9d/0x130 __x64_sys_write+0x4c/0x60 do_syscall_64+0x91/0xb05 entry_SYSCALL_64_after_hwframe+0x49/0xbe 5 locks held by fsync04/25724: #0: ffff99f9911093f8 (sb_writers#13){.+.+}, at: vfs_write+0x21c/0x260 #1: ffff99f9db4c0348 (&sb->s_type->i_mutex_key#15){+.+.}, at: ext4_buffered_write_iter+0x65/0x210 [ext4] #2: ffff99f5e7dfcf58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2] #3: ffff99f9db4c0168 (&ei->i_data_sem){++++}, at: ext4_map_blocks+0x176/0x950 [ext4] #4: ffffffff99086b40 (rcu_read_lock){....}, at: jbd2_write_access_granted+0x4e/0x250 [jbd2] irq event stamp: 1407125 hardirqs last enabled at (1407125): [<ffffffff980da9b7>] __find_get_block+0x107/0x790 hardirqs last disabled at (1407124): [<ffffffff980da8f9>] __find_get_block+0x49/0x790 softirqs last enabled at (1405528): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c softirqs last disabled at (1405521): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0 Reported by Kernel Concurrency Sanitizer on: CPU: 68 PID: 25724 Comm: fsync04 Tainted: G L 5.6.0-rc2-next-20200221+ #7 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 The plain reads are outside of jh->b_state_lock critical section which result in data races. Fix them by adding pairs of READ|WRITE_ONCE(). Reviewed-by: Jan Kara <[email protected]> Signed-off-by: Qian Cai <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Theodore Ts'o <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

…event commit 7d36665 upstream. An eventfd monitors multiple memory thresholds of the cgroup, closes them, the kernel deletes all events related to this eventfd. Before all events are deleted, another eventfd monitors the memory threshold of this cgroup, leading to a crash: BUG: kernel NULL pointer dereference, address: 0000000000000004 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 800000033058e067 P4D 800000033058e067 PUD 3355ce067 PMD 0 Oops: 0002 [#1] SMP PTI CPU: 2 PID: 14012 Comm: kworker/2:6 Kdump: loaded Not tainted 5.6.0-rc4 #3 Hardware name: LENOVO 20AWS01K00/20AWS01K00, BIOS GLET70WW (2.24 ) 05/21/2014 Workqueue: events memcg_event_remove RIP: 0010:__mem_cgroup_usage_unregister_event+0xb3/0x190 RSP: 0018:ffffb47e01c4fe18 EFLAGS: 00010202 RAX: 0000000000000001 RBX: ffff8bb223a8a000 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffff8bb22fb83540 RDI: 0000000000000001 RBP: ffffb47e01c4fe48 R08: 0000000000000000 R09: 0000000000000010 R10: 000000000000000c R11: 071c71c71c71c71c R12: ffff8bb226aba880 R13: ffff8bb223a8a480 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8bb242680000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000004 CR3: 000000032c29c003 CR4: 00000000001606e0 Call Trace: memcg_event_remove+0x32/0x90 process_one_work+0x172/0x380 worker_thread+0x49/0x3f0 kthread+0xf8/0x130 ret_from_fork+0x35/0x40 CR2: 0000000000000004 We can reproduce this problem in the following ways: 1. We create a new cgroup subdirectory and a new eventfd, and then we monitor multiple memory thresholds of the cgroup through this eventfd. 2. closing this eventfd, and __mem_cgroup_usage_unregister_event () will be called multiple times to delete all events related to this eventfd. The first time __mem_cgroup_usage_unregister_event() is called, the kernel will clear all items related to this eventfd in thresholds-> primary. Since there is currently only one eventfd, thresholds-> primary becomes empty, so the kernel will set thresholds-> primary and hresholds-> spare to NULL. If at this time, the user creates a new eventfd and monitor the memory threshold of this cgroup, kernel will re-initialize thresholds-> primary. Then when __mem_cgroup_usage_unregister_event () is called for the second time, because thresholds-> primary is not empty, the system will access thresholds-> spare, but thresholds-> spare is NULL, which will trigger a crash. In general, the longer it takes to delete all events related to this eventfd, the easier it is to trigger this problem. The solution is to check whether the thresholds associated with the eventfd has been cleared when deleting the event. If so, we do nothing. [[email protected]: fix comment, per Kirill] Fixes: 907860e ("cgroups: make cftype.unregister_event() void-returning") Signed-off-by: Chunguang Xu <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Acked-by: Michal Hocko <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Vladimir Davydov <[email protected]> Cc: <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>