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| author | Breno Leitao <leitao@debian.org> | 2026-06-15 10:49:07 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-07-28 21:11:49 -0700 |
| commit | eb11f56eeca56069613d00bf623607e305b271d9 (patch) | |
| tree | f4c9190f986047ec10dc7e4fea84d2710f86c38b | |
| parent | 5d10d4e19e6daa487f0cd0ea6cba472325de92f9 (diff) | |
| download | linux-next-eb11f56eeca56069613d00bf623607e305b271d9.tar.gz linux-next-eb11f56eeca56069613d00bf623607e305b271d9.zip | |
mm/kmemleak: stop the task stack scan early when interrupted
scan_block() already checks scan_should_stop() for every pointer and bails
out of the current block, but the task stack walk cannot tell and keeps
issuing a separate scan_should_stop() between every task.
Return that status from scan_block() and use it as the task stack loop
condition, so the walk stops as soon as a scan is interrupted.
Link: https://lore.kernel.org/20260615-kmemleak-stack-resched-v3-2-acecd7d7fd92@debian.org
Signed-off-by: Breno Leitao <leitao@debian.org>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Qian Cai <cai@lca.pw>
Cc: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | mm/kmemleak.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 16b72cead07d..bc79e293531b 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -1525,22 +1525,25 @@ static int scan_should_stop(void) /* * Scan a memory block (exclusive range) for valid pointers and add those - * found to the gray list. + * found to the gray list. Return non-zero if the scan was interrupted. */ -static void scan_block(void *_start, void *_end, - struct kmemleak_object *scanned) +static int scan_block(void *_start, void *_end, + struct kmemleak_object *scanned) { unsigned long *ptr; unsigned long *start = PTR_ALIGN(_start, BYTES_PER_POINTER); unsigned long *end = _end - (BYTES_PER_POINTER - 1); unsigned long flags; + int stop = 0; raw_spin_lock_irqsave(&kmemleak_lock, flags); for (ptr = start; ptr < end; ptr++) { unsigned long pointer; - if (scan_should_stop()) + if (scan_should_stop()) { + stop = 1; break; + } kasan_disable_current(); pointer = *(unsigned long *)kasan_reset_tag((void *)ptr); @@ -1550,6 +1553,8 @@ static void scan_block(void *_start, void *_end, pointer_update_refs(scanned, pointer, OBJECT_PERCPU); } raw_spin_unlock_irqrestore(&kmemleak_lock, flags); + + return stop; } /* @@ -1705,6 +1710,7 @@ static void kmemleak_scan_task_stacks(void) { struct pid *pid; int nr = 1; + int stop = 0; do { struct task_struct *p = NULL; @@ -1723,13 +1729,13 @@ static void kmemleak_scan_task_stacks(void) void *stack = try_get_task_stack(p); if (stack) { - scan_block(stack, stack + THREAD_SIZE, NULL); + stop = scan_block(stack, stack + THREAD_SIZE, NULL); put_task_stack(p); } put_task_struct(p); } cond_resched(); - } while (pid && !scan_should_stop()); + } while (pid && !stop); } /* |