BUILD: Fix various build warnings

ci/azure-pipelines.yml

@@ -96,6 +96,8 @@ stages:
               set -eEx
               ./autogen.sh
               kernel_ver=$(rpm -qa | grep kernel-devel | cut -d'-' -f3-)
+              export CFLAGS='-Werror -Wall'
+              export KFLAGS='-Werror'
               ./configure --with-kerneldir=/usr/src/kernels/${kernel_ver}
               make
             displayName: Build on CentOS
@@ -105,6 +107,8 @@ stages:
               set -eEx
               ./autogen.sh
               kernel_ver=$(dpkg -l | grep 'linux-headers-.*-generic' | awk '{print $2}')
+              export CFLAGS='-Werror -Wall'
+              export KFLAGS='-Werror'
               ./configure --enable-gtest --with-kerneldir=/usr/src/${kernel_ver}
               make
             displayName: Build on Ubuntu

ci/vm/provision2.sh

@@ -4,6 +4,9 @@ set -Exeuo pipefail
 OS=$1
 PR_NUM=$2
 
+export CFLAGS="-Werror -Wall"
+export KFLAGS="-Werror"
+
 xpmem_build() {
   uname -r
   gcc --version

kernel/Makefile.am

@@ -19,8 +19,8 @@ EXTRA_DIST = ${module_sources}
 
 module_DATA = $(MODULE)
 
-
-KCPPFLAGS = -include @abs_top_builddir@/config.h -I@abs_top_srcdir@/include
+KCPPFLAGS = -include @abs_top_builddir@/config.h -I@abs_top_srcdir@/include \
+	    $(KFLAGS)
 export KCPPFLAGS
 
 $(MODULE): ${module_sources}

kernel/xpmem_pfn.c

@@ -321,6 +321,8 @@ xpmem_remap_pages(struct xpmem_segment *seg,
 	return ctx.result;
 }
 
+static DEFINE_PER_CPU(cpumask_t, saved_mask_percpu);
+
 /*
  * Fault in and pin a single page for the specified task and mm.
  */
@@ -329,9 +331,9 @@ xpmem_pin_pages(struct xpmem_thread_group *tg, struct task_struct *src_task,
 	       struct mm_struct *src_mm, u64 vaddr, struct page **pages,
 	       unsigned long count)
 {
+	cpumask_t *saved_mask = NULL;
 	long nr_pinned;
 	struct vm_area_struct *vma;
-	cpumask_t saved_mask = CPU_MASK_NONE;
 	int foll_write;
 	unsigned long avail;
 
@@ -357,10 +359,12 @@ xpmem_pin_pages(struct xpmem_thread_group *tg, struct task_struct *src_task,
 	 */
 	if (xpmem_vaddr_to_pte_offset(src_mm, vaddr, NULL) == NULL &&
 	    cpu_to_node(task_cpu(current)) != cpu_to_node(task_cpu(src_task))) {
+		saved_mask = this_cpu_ptr(&saved_mask_percpu);
+
 #ifdef HAVE_STRUCT_TASK_STRUCT_CPUS_MASK
-		saved_mask = current->cpus_mask;
+		*saved_mask = current->cpus_mask;
 #else
-		saved_mask = current->cpus_allowed;
+		*saved_mask = current->cpus_allowed;
 #endif
 		set_cpus_allowed_ptr(current, cpumask_of(task_cpu(src_task)));
 	}
@@ -388,8 +392,9 @@ xpmem_pin_pages(struct xpmem_thread_group *tg, struct task_struct *src_task,
 	nr_pinned = get_user_pages (src_task, src_mm, vaddr, count, foll_write, 0,
 			      pages, NULL);
 #endif
-	if (!cpumask_empty(&saved_mask))
-		set_cpus_allowed_ptr(current, &saved_mask);
+	if (saved_mask) {
+		set_cpus_allowed_ptr(current, saved_mask);
+	}
 
 	if (nr_pinned > 0) {
 		atomic_long_add(nr_pinned, &tg->n_pinned);

kernel/xpmem_private.h

@@ -268,7 +268,7 @@ struct xpmem_partition {
  */
 #define XPMEM_MAX_PAGE_FAULT_AFTER 32
 #define XPMEM_MAX_PAGE_FAULT_BEFORE 16
-#define XPMEM_MAX_PAGE_FAULTS 128
+#define XPMEM_MAX_PAGE_FAULTS 96
 
 struct xpmem_config {
 	rwlock_t lock;

m4/ac_path_kernel_source.m4

@@ -101,7 +101,9 @@ AC_DEFUN([AC_KERNEL_CHECKS],
                            -e s/sparc32.*/sparc/ \
                            -e s/sparc64.*/sparc/ \
                            -e s/s390x/s390/)
+  save_CFLAGS="$CFLAGS"
   save_CPPFLAGS="$CPPFLAGS"
+  CFLAGS=
   CPPFLAGS="-include $kerneldir/include/linux/kconfig.h \
             -include $kerneldir/include/linux/compiler.h \
             -D__KERNEL__ \
@@ -148,6 +150,8 @@ AC_DEFUN([AC_KERNEL_CHECKS],
 
   AC_CHECK_DECLS([vm_flags_set], [], [], [[#include <linux/mm.h>]])
 
+  AC_SUBST(KFLAGS, [$KFLAGS])
   CPPFLAGS="$save_CPPFLAGS"
+  CFLAGS="$save_CFLAGS"
 ]
 )

test/share/include/xpmem_test.h

@@ -6,9 +6,9 @@
 
 #define NR_TEST_PAGES 	4
 #define PAGE_SIZE	page_size()
-#define SHARE_SIZE	NR_TEST_PAGES * PAGE_SIZE
-#define PAGE_INT_SIZE	(PAGE_SIZE / sizeof(int))
-#define SHARE_INT_SIZE	(SHARE_SIZE / sizeof(int))
+#define SHARE_SIZE	(NR_TEST_PAGES * PAGE_SIZE)
+#define PAGE_INT_SIZE	((int)(PAGE_SIZE / sizeof(int)))
+#define SHARE_INT_SIZE	((int)(SHARE_SIZE / sizeof(int)))
 
 /* Used to specify size of /tmp/xpmem.share */
 #define TMP_SHARE_SIZE	32
@@ -46,7 +46,7 @@ xpmem_segid_t make_share(int **data, size_t size)
 		return -1;
 	}
 
-	for (i=0; i < (size / sizeof(int)); i++)
+	for (i=0; i < (int)(size / sizeof(int)); i++)
 		*(ptr + i) = i;
 
 	segid = xpmem_make(ptr, size, XPMEM_PERMIT_MODE, (void *)0666);

test/share/xpmem_master.c

@@ -21,12 +21,12 @@
 		printf("==== %s PASSED ====\n\n", (name)) :	\
 		printf("==== %s FAILED ====\n\n", (name)))
 
-int test_base(test_args* t) { return 0; }
-int test_two_attach(test_args* t) { return 0; }
-int test_two_shares(test_args* t) { return 0; }
-int test_fork(test_args* t) { return 0; }
+int test_base(test_args* t) { (void)t; return 0; }
+int test_two_attach(test_args* t) { (void)t; return 0; }
+int test_two_shares(test_args* t) { (void)t; return 0; }
+int test_fork(test_args* t) { (void)t; return 0; }
 
-int main(int argc, char** argv)
+int main(void)
 {
 	pid_t p1, p2;
 	int i, fd, lock, status[2];

test/share/xpmem_proc2.c

@@ -198,7 +198,7 @@ int test_fork(test_args *xpmem_args)
 	printf("xpmem_proc2: reading to pin pages\n");
 	for (i = 0; i < PAGE_INT_SIZE; i++) {
 		if (*(data + i) != PAGE_INT_SIZE + i) {
-			printf("xpmem_proc2: ***mismatch at %d: expected %lu "
+			printf("xpmem_proc2: ***mismatch at %d: expected %d "
 				"got %d\n", i, PAGE_INT_SIZE + i, *(data + i));
 			ret = -2;
 		}