2020-03-03 21:43:11

by Qian Cai

Subject: [PATCH -next 2/2] Revert "mm/kmemleak: annotate various data races obj->ptr"

This reverts commit a03184297d546c6531cdd40878f1f50732d3bac9.

Signed-off-by: Qian Cai <[email protected]>
---
mm/kmemleak.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 788dc5509539..e362dc3d2028 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1169,12 +1169,7 @@ static bool update_checksum(struct kmemleak_object *object)
u32 old_csum = object->checksum;

kasan_disable_current();
- /*
- * crc32() will dereference object->pointer. If an unstable value was
- * returned due to a data race, it will be corrected in the next scan.
- */
- object->checksum = data_race(crc32(0, (void *)object->pointer,
- object->size));
+ object->checksum = crc32(0, (void *)object->pointer, object->size);
kasan_enable_current();

return object->checksum != old_csum;
@@ -1248,7 +1243,7 @@ static void scan_block(void *_start, void *_end,
break;

kasan_disable_current();
- pointer = data_race(*ptr);
+ pointer = *ptr;
kasan_enable_current();

untagged_ptr = (unsigned long)kasan_reset_tag((void *)pointer);
--
1.8.3.1

2020-03-03 21:47:54

by Marco Elver

Subject: Re: [PATCH -next 2/2] Revert "mm/kmemleak: annotate various data races obj->ptr"

On Tue, 3 Mar 2020 at 20:28, Qian Cai <[email protected]> wrote:
>
> This reverts commit a03184297d546c6531cdd40878f1f50732d3bac9.
>
> Signed-off-by: Qian Cai <[email protected]>

Acked-by: Marco Elver <[email protected]>

Thank you!

> ---
> mm/kmemleak.c | 9 ++-------
> 1 file changed, 2 insertions(+), 7 deletions(-)
>
> diff --git a/mm/kmemleak.c b/mm/kmemleak.c
> index 788dc5509539..e362dc3d2028 100644
> --- a/mm/kmemleak.c
> +++ b/mm/kmemleak.c
> @@ -1169,12 +1169,7 @@ static bool update_checksum(struct kmemleak_object *object)
> u32 old_csum = object->checksum;
>
> kasan_disable_current();
> - /*
> - * crc32() will dereference object->pointer. If an unstable value was
> - * returned due to a data race, it will be corrected in the next scan.
> - */
> - object->checksum = data_race(crc32(0, (void *)object->pointer,
> - object->size));
> + object->checksum = crc32(0, (void *)object->pointer, object->size);
> kasan_enable_current();
>
> return object->checksum != old_csum;
> @@ -1248,7 +1243,7 @@ static void scan_block(void *_start, void *_end,
> break;
>
> kasan_disable_current();
> - pointer = data_race(*ptr);
> + pointer = *ptr;
> kasan_enable_current();
>
> untagged_ptr = (unsigned long)kasan_reset_tag((void *)pointer);
> --
> 1.8.3.1
>

2020-03-11 14:19:57

by Catalin Marinas

Subject: Re: [PATCH -next 2/2] Revert "mm/kmemleak: annotate various data races obj->ptr"

On Tue, Mar 03, 2020 at 02:28:36PM -0500, Qian Cai wrote:
> This reverts commit a03184297d546c6531cdd40878f1f50732d3bac9.
>
> Signed-off-by: Qian Cai <[email protected]>

Acked-by: Catalin Marinas <[email protected]>