6.12-stable review patch. If anyone has any objections, please let me know.
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From: Peter Zijlstra peterz@infradead.org
[ Upstream commit a1b65f3f7c6f7f0a08a7dba8be458c6415236487 ]
Turns out that this commit, about 10 years ago:
9ec23531fd48 ("sched/preempt, mm/fault: Trigger might_sleep() in might_fault() with disabled pagefaults")
... accidentally (and unnessecarily) put the lockdep part of __might_fault() under CONFIG_DEBUG_ATOMIC_SLEEP=y.
This is potentially notable because large distributions such as Ubuntu are running with !CONFIG_DEBUG_ATOMIC_SLEEP.
Restore the debug check.
[ mingo: Update changelog. ]
Fixes: 9ec23531fd48 ("sched/preempt, mm/fault: Trigger might_sleep() in might_fault() with disabled pagefaults") Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Ingo Molnar mingo@kernel.org Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Andrew Morton akpm@linux-foundation.org Link: https://lore.kernel.org/r/20241104135517.536628371@infradead.org Signed-off-by: Sasha Levin sashal@kernel.org --- mm/memory.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c index 525f96ad65b8d..01c0b3a5a4d66 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -6718,10 +6718,8 @@ void __might_fault(const char *file, int line) if (pagefault_disabled()) return; __might_sleep(file, line); -#if defined(CONFIG_DEBUG_ATOMIC_SLEEP) if (current->mm) might_lock_read(¤t->mm->mmap_lock); -#endif } EXPORT_SYMBOL(__might_fault); #endif