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| author | Pekka Enberg <penberg@cs.helsinki.fi> | 2009-08-27 14:50:00 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2009-09-04 16:05:55 +0100 |
| commit | 8e019366ba749a536131cde1947af6dcaccf8e8f (patch) | |
| tree | fc44a33fc43265652b93f6f3251d5a73cda2e5ee /mm/kmemleak.c | |
| parent | acde31dc467797ccae3a55b791a77af446cce018 (diff) | |
| download | lwn-8e019366ba749a536131cde1947af6dcaccf8e8f.tar.gz lwn-8e019366ba749a536131cde1947af6dcaccf8e8f.zip | |
kmemleak: Don't scan uninitialized memory when kmemcheck is enabled
Ingo Molnar reported the following kmemcheck warning when running both
kmemleak and kmemcheck enabled:
PM: Adding info for No Bus:vcsa7
WARNING: kmemcheck: Caught 32-bit read from uninitialized memory
(f6f6e1a4)
d873f9f600000000c42ae4c1005c87f70000000070665f666978656400000000
i i i i u u u u i i i i i i i i i i i i i i i i i i i i i u u u
^
Pid: 3091, comm: kmemleak Not tainted (2.6.31-rc7-tip #1303) P4DC6
EIP: 0060:[<c110301f>] EFLAGS: 00010006 CPU: 0
EIP is at scan_block+0x3f/0xe0
EAX: f40bd700 EBX: f40bd780 ECX: f16b46c0 EDX: 00000001
ESI: f6f6e1a4 EDI: 00000000 EBP: f10f3f4c ESP: c2605fcc
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
CR0: 8005003b CR2: e89a4844 CR3: 30ff1000 CR4: 000006f0
DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
DR6: ffff4ff0 DR7: 00000400
[<c110313c>] scan_object+0x7c/0xf0
[<c1103389>] kmemleak_scan+0x1d9/0x400
[<c1103a3c>] kmemleak_scan_thread+0x4c/0xb0
[<c10819d4>] kthread+0x74/0x80
[<c10257db>] kernel_thread_helper+0x7/0x3c
[<ffffffff>] 0xffffffff
kmemleak: 515 new suspected memory leaks (see
/sys/kernel/debug/kmemleak)
kmemleak: 42 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
The problem here is that kmemleak will scan partially initialized
objects that makes kmemcheck complain. Fix that up by skipping
uninitialized memory regions when kmemcheck is enabled.
Reported-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Diffstat (limited to 'mm/kmemleak.c')
| -rw-r--r-- | mm/kmemleak.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 1d7645b0a97c..c494fee7a2b5 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -97,6 +97,7 @@ #include <asm/processor.h> #include <asm/atomic.h> +#include <linux/kmemcheck.h> #include <linux/kmemleak.h> /* @@ -967,15 +968,22 @@ static void scan_block(void *_start, void *_end, unsigned long *end = _end - (BYTES_PER_POINTER - 1); for (ptr = start; ptr < end; ptr++) { - unsigned long flags; - unsigned long pointer = *ptr; struct kmemleak_object *object; + unsigned long flags; + unsigned long pointer; if (allow_resched) cond_resched(); if (scan_should_stop()) break; + /* don't scan uninitialized memory */ + if (!kmemcheck_is_obj_initialized((unsigned long)ptr, + BYTES_PER_POINTER)) + continue; + + pointer = *ptr; + object = find_and_get_object(pointer, 1); if (!object) continue; |