Messages in this thread | | | Date | Mon, 8 Feb 2010 14:54:00 +0200 | Subject | Re: [PATCH] kmemcheck: Test the full object in kmemcheck_is_obj_initialized() | From | Pekka Enberg <> |
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On Mon, Feb 8, 2010 at 1:16 PM, Catalin Marinas <catalin.marinas@arm.com> wrote: > This is a fix for bug #14845 (bugzilla.kernel.org). The > update_checksum() function in mm/kmemleak.c calls > kmemcheck_is_obj_initialised() before scanning an object. When > KMEMCHECK_PARTIAL_OK is enabled, this function returns true. However, > the crc32_le() reads smaller intervals (32-bit) for which > kmemleak_is_obj_initialised() may be false leading to a kmemcheck > warning. > > Note that kmemcheck_is_obj_initialized() is currently only used by > kmemleak before scanning a memory location. > > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Christian Casteyde <casteyde.christian@free.fr> > Cc: Pekka Enberg <penberg@cs.helsinki.fi> > Cc: Vegard Nossum <vegardno@ifi.uio.no>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Andrew, Vegard has been rather quiet lately so do you mind picking up this patch? Alternatively, I can pick it up in slab.git if you so prefer.
> --- > arch/x86/mm/kmemcheck/kmemcheck.c | 2 +- > arch/x86/mm/kmemcheck/shadow.c | 16 ++++++++++++++-- > arch/x86/mm/kmemcheck/shadow.h | 2 ++ > 3 files changed, 17 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/mm/kmemcheck/kmemcheck.c b/arch/x86/mm/kmemcheck/kmemcheck.c > index 8cc1833..b3b531a 100644 > --- a/arch/x86/mm/kmemcheck/kmemcheck.c > +++ b/arch/x86/mm/kmemcheck/kmemcheck.c > @@ -337,7 +337,7 @@ bool kmemcheck_is_obj_initialized(unsigned long addr, size_t size) > if (!shadow) > return true; > > - status = kmemcheck_shadow_test(shadow, size); > + status = kmemcheck_shadow_test_all(shadow, size); > > return status == KMEMCHECK_SHADOW_INITIALIZED; > } > diff --git a/arch/x86/mm/kmemcheck/shadow.c b/arch/x86/mm/kmemcheck/shadow.c > index 3f66b82..aec1242 100644 > --- a/arch/x86/mm/kmemcheck/shadow.c > +++ b/arch/x86/mm/kmemcheck/shadow.c > @@ -125,12 +125,12 @@ void kmemcheck_mark_initialized_pages(struct page *p, unsigned int n) > > enum kmemcheck_shadow kmemcheck_shadow_test(void *shadow, unsigned int size) > { > +#ifdef CONFIG_KMEMCHECK_PARTIAL_OK > uint8_t *x; > unsigned int i; > > x = shadow; > > -#ifdef CONFIG_KMEMCHECK_PARTIAL_OK > /* > * Make sure _some_ bytes are initialized. Gcc frequently generates > * code to access neighboring bytes. > @@ -139,13 +139,25 @@ enum kmemcheck_shadow kmemcheck_shadow_test(void *shadow, unsigned int size) > if (x[i] == KMEMCHECK_SHADOW_INITIALIZED) > return x[i]; > } > + > + return x[0]; > #else > + return kmemcheck_shadow_test_all(shadow, size); > +#endif > +} > + > +enum kmemcheck_shadow kmemcheck_shadow_test_all(void *shadow, unsigned int size) > +{ > + uint8_t *x; > + unsigned int i; > + > + x = shadow; > + > /* All bytes must be initialized. */ > for (i = 0; i < size; ++i) { > if (x[i] != KMEMCHECK_SHADOW_INITIALIZED) > return x[i]; > } > -#endif > > return x[0]; > } > diff --git a/arch/x86/mm/kmemcheck/shadow.h b/arch/x86/mm/kmemcheck/shadow.h > index af46d9a..ff0b2f7 100644 > --- a/arch/x86/mm/kmemcheck/shadow.h > +++ b/arch/x86/mm/kmemcheck/shadow.h > @@ -11,6 +11,8 @@ enum kmemcheck_shadow { > void *kmemcheck_shadow_lookup(unsigned long address); > > enum kmemcheck_shadow kmemcheck_shadow_test(void *shadow, unsigned int size); > +enum kmemcheck_shadow kmemcheck_shadow_test_all(void *shadow, > + unsigned int size); > void kmemcheck_shadow_set(void *shadow, unsigned int size); > > #endif > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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