The kernel may sleep under a spinlock, and the function call paths are:
afs_do_unlk (acquire the spinlock)
posix_lock_file
posix_lock_inode (fs/locks.c)
locks_get_lock_context
kmem_cache_alloc(GFP_KERNEL) --> may sleep
afs_do_setlk (acquire the spinlock)
posix_lock_file
posix_lock_inode (fs/locks.c)
locks_get_lock_context
kmem_cache_alloc(GFP_KERNEL) --> may sleep
To fix them, GFP_KERNEL is replaced with GFP_ATOMIC.
These bugs are found by my static analysis tool and my code review.
Signed-off-by: Jia-Ju Bai <[email protected]>
---
fs/locks.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/locks.c b/fs/locks.c
index 1bd71c4..975cc62 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -222,7 +222,7 @@ struct file_lock_list_struct {
if (likely(ctx) || type == F_UNLCK)
goto out;
- ctx = kmem_cache_alloc(flctx_cache, GFP_KERNEL);
+ ctx = kmem_cache_alloc(flctx_cache, GFP_ATOMIC);
if (!ctx)
goto out;
--
1.7.9.5
