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Diffstat (limited to 'mm/shmem.c')
-rw-r--r--mm/shmem.c16
1 files changed, 12 insertions, 4 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index b0aa6075d164..fbcb3c96a186 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1022,7 +1022,11 @@ static int shmem_setattr(struct dentry *dentry, struct iattr *attr)
 			 */
 			if (IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE)) {
 				spin_lock(&sbinfo->shrinklist_lock);
-				if (list_empty(&info->shrinklist)) {
+				/*
+				 * _careful to defend against unlocked access to
+				 * ->shrink_list in shmem_unused_huge_shrink()
+				 */
+				if (list_empty_careful(&info->shrinklist)) {
 					list_add_tail(&info->shrinklist,
 							&sbinfo->shrinklist);
 					sbinfo->shrinklist_len++;
@@ -1817,7 +1821,11 @@ alloc_nohuge:		page = shmem_alloc_and_acct_page(gfp, info, sbinfo,
 			 * to shrink under memory pressure.
 			 */
 			spin_lock(&sbinfo->shrinklist_lock);
-			if (list_empty(&info->shrinklist)) {
+			/*
+			 * _careful to defend against unlocked access to
+			 * ->shrink_list in shmem_unused_huge_shrink()
+			 */
+			if (list_empty_careful(&info->shrinklist)) {
 				list_add_tail(&info->shrinklist,
 						&sbinfo->shrinklist);
 				sbinfo->shrinklist_len++;
@@ -3959,7 +3967,7 @@ int __init shmem_init(void)
 	}
 
 #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
-	if (has_transparent_hugepage() && shmem_huge < SHMEM_HUGE_DENY)
+	if (has_transparent_hugepage() && shmem_huge > SHMEM_HUGE_DENY)
 		SHMEM_SB(shm_mnt->mnt_sb)->huge = shmem_huge;
 	else
 		shmem_huge = 0; /* just in case it was patched */
@@ -4020,7 +4028,7 @@ static ssize_t shmem_enabled_store(struct kobject *kobj,
 		return -EINVAL;
 
 	shmem_huge = huge;
-	if (shmem_huge < SHMEM_HUGE_DENY)
+	if (shmem_huge > SHMEM_HUGE_DENY)
 		SHMEM_SB(shm_mnt->mnt_sb)->huge = shmem_huge;
 	return count;
 }