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authorTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>2023-05-11 15:47:32 +0200
committerThomas Gleixner <tglx@linutronix.de>2023-05-22 14:52:58 +0200
commiteb799279fb1f9c63c520fe8c1c41cb9154252db6 (patch)
treeb08af898ed7e318df35b97abb6650f5efdcfdaf8 /lib
parentdebugobjects,locking: Annotate debug_object_fill_pool() wait type violation (diff)
downloadlinux-eb799279fb1f9c63c520fe8c1c41cb9154252db6.tar.xz
linux-eb799279fb1f9c63c520fe8c1c41cb9154252db6.zip
debugobjects: Don't wake up kswapd from fill_pool()
syzbot is reporting a lockdep warning in fill_pool() because the allocation from debugobjects is using GFP_ATOMIC, which is (__GFP_HIGH | __GFP_KSWAPD_RECLAIM) and therefore tries to wake up kswapd, which acquires kswapd_wait::lock. Since fill_pool() might be called with arbitrary locks held, fill_pool() should not assume that acquiring kswapd_wait::lock is safe. Use __GFP_HIGH instead and remove __GFP_NORETRY as it is pointless for !__GFP_DIRECT_RECLAIM allocation. Fixes: 3ac7fe5a4aab ("infrastructure to debug (dynamic) objects") Reported-by: syzbot <syzbot+fe0c72f0ccbb93786380@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/6577e1fa-b6ee-f2be-2414-a2b51b1c5e30@I-love.SAKURA.ne.jp Closes: https://syzkaller.appspot.com/bug?extid=fe0c72f0ccbb93786380
Diffstat (limited to 'lib')
-rw-r--r--lib/debugobjects.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index 826c617b10a7..984985c39c9b 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -126,7 +126,7 @@ static const char *obj_states[ODEBUG_STATE_MAX] = {
static void fill_pool(void)
{
- gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
+ gfp_t gfp = __GFP_HIGH | __GFP_NOWARN;
struct debug_obj *obj;
unsigned long flags;