| Message ID | b16c90197bb2c06c780e6e981c40345e03fda465.1546450432.git.andreyknvl@google.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | kasan: tag-based mode fixes | expand |
On Wed, 2 Jan 2019 18:36:06 +0100 Andrey Konovalov <andreyknvl@google.com> wrote: > Instead of changing cache->align to be aligned to KASAN_SHADOW_SCALE_SIZE > in kasan_cache_create() we can reuse the ARCH_SLAB_MINALIGN macro. > > ... > > --- a/arch/arm64/include/asm/kasan.h > +++ b/arch/arm64/include/asm/kasan.h > @@ -36,6 +36,10 @@ > #define KASAN_SHADOW_OFFSET (KASAN_SHADOW_END - (1ULL << \ > (64 - KASAN_SHADOW_SCALE_SHIFT))) > > +#ifdef CONFIG_KASAN_SW_TAGS > +#define ARCH_SLAB_MINALIGN (1ULL << KASAN_SHADOW_SCALE_SHIFT) > +#endif > + > void kasan_init(void); > void kasan_copy_shadow(pgd_t *pgdir); > asmlinkage void kasan_early_init(void); > diff --git a/include/linux/slab.h b/include/linux/slab.h > index 11b45f7ae405..d87f913ab4e8 100644 > --- a/include/linux/slab.h > +++ b/include/linux/slab.h > @@ -16,6 +16,7 @@ > #include <linux/overflow.h> > #include <linux/types.h> > #include <linux/workqueue.h> > +#include <linux/kasan.h> > This still seems unadvisable. Like other architectures, arm defines ARCH_SLAB_MINALIGN in arch/arm/include/asm/cache.h. arch/arm/include/asm64/cache.h doesn't define ARCH_SLAB_MINALIGN afaict. If arch/arm/include/asm64/cache.h later gets a definition of ARCH_SLAB_MINALIGN then we again face the risk that different .c files will see different values of ARCH_SLAB_MINALIGN depending on which headers they include. So what to say about this? The architecture's ARCH_SLAB_MINALIGN should be defined in the architecture's cache.h, end of story. Not in slab.h, not in kasan.h.
On Wed, Jan 02, 2019 at 12:14:36PM -0800, Andrew Morton wrote: > On Wed, 2 Jan 2019 18:36:06 +0100 Andrey Konovalov <andreyknvl@google.com> wrote: > > > Instead of changing cache->align to be aligned to KASAN_SHADOW_SCALE_SIZE > > in kasan_cache_create() we can reuse the ARCH_SLAB_MINALIGN macro. > > > > ... > > > > --- a/arch/arm64/include/asm/kasan.h > > +++ b/arch/arm64/include/asm/kasan.h > > @@ -36,6 +36,10 @@ > > #define KASAN_SHADOW_OFFSET (KASAN_SHADOW_END - (1ULL << \ > > (64 - KASAN_SHADOW_SCALE_SHIFT))) > > > > +#ifdef CONFIG_KASAN_SW_TAGS > > +#define ARCH_SLAB_MINALIGN (1ULL << KASAN_SHADOW_SCALE_SHIFT) > > +#endif > > + > > void kasan_init(void); > > void kasan_copy_shadow(pgd_t *pgdir); > > asmlinkage void kasan_early_init(void); > > diff --git a/include/linux/slab.h b/include/linux/slab.h > > index 11b45f7ae405..d87f913ab4e8 100644 > > --- a/include/linux/slab.h > > +++ b/include/linux/slab.h > > @@ -16,6 +16,7 @@ > > #include <linux/overflow.h> > > #include <linux/types.h> > > #include <linux/workqueue.h> > > +#include <linux/kasan.h> > > > > This still seems unadvisable. Like other architectures, arm defines > ARCH_SLAB_MINALIGN in arch/arm/include/asm/cache.h. > arch/arm/include/asm64/cache.h doesn't define ARCH_SLAB_MINALIGN > afaict. > > If arch/arm/include/asm64/cache.h later gets a definition of > ARCH_SLAB_MINALIGN then we again face the risk that different .c files > will see different values of ARCH_SLAB_MINALIGN depending on which > headers they include. > > So what to say about this? The architecture's ARCH_SLAB_MINALIGN > should be defined in the architecture's cache.h, end of story. Not in > slab.h, not in kasan.h. Agreed. Also, as far as I can tell, this patch isn't actually a fix (unlike the other two in this series) so it should be harmless to drop it for now. Will
On Wed, Jan 2, 2019 at 9:14 PM Andrew Morton <akpm@linux-foundation.org> wrote: > > On Wed, 2 Jan 2019 18:36:06 +0100 Andrey Konovalov <andreyknvl@google.com> wrote: > > > Instead of changing cache->align to be aligned to KASAN_SHADOW_SCALE_SIZE > > in kasan_cache_create() we can reuse the ARCH_SLAB_MINALIGN macro. > > > > ... > > > > --- a/arch/arm64/include/asm/kasan.h > > +++ b/arch/arm64/include/asm/kasan.h > > @@ -36,6 +36,10 @@ > > #define KASAN_SHADOW_OFFSET (KASAN_SHADOW_END - (1ULL << \ > > (64 - KASAN_SHADOW_SCALE_SHIFT))) > > > > +#ifdef CONFIG_KASAN_SW_TAGS > > +#define ARCH_SLAB_MINALIGN (1ULL << KASAN_SHADOW_SCALE_SHIFT) > > +#endif > > + > > void kasan_init(void); > > void kasan_copy_shadow(pgd_t *pgdir); > > asmlinkage void kasan_early_init(void); > > diff --git a/include/linux/slab.h b/include/linux/slab.h > > index 11b45f7ae405..d87f913ab4e8 100644 > > --- a/include/linux/slab.h > > +++ b/include/linux/slab.h > > @@ -16,6 +16,7 @@ > > #include <linux/overflow.h> > > #include <linux/types.h> > > #include <linux/workqueue.h> > > +#include <linux/kasan.h> > > > > This still seems unadvisable. Like other architectures, arm defines > ARCH_SLAB_MINALIGN in arch/arm/include/asm/cache.h. > arch/arm/include/asm64/cache.h doesn't define ARCH_SLAB_MINALIGN > afaict. > > If arch/arm/include/asm64/cache.h later gets a definition of > ARCH_SLAB_MINALIGN then we again face the risk that different .c files > will see different values of ARCH_SLAB_MINALIGN depending on which > headers they include. > > So what to say about this? The architecture's ARCH_SLAB_MINALIGN > should be defined in the architecture's cache.h, end of story. Not in > slab.h, not in kasan.h. Done in v3, thanks! > > > -- > You received this message because you are subscribed to the Google Groups "kasan-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@googlegroups.com. > To post to this group, send email to kasan-dev@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/20190102121436.5c2b72d1b0ec49affadc9692%40linux-foundation.org. > For more options, visit https://groups.google.com/d/optout.
diff --git a/arch/arm64/include/asm/kasan.h b/arch/arm64/include/asm/kasan.h index b52aacd2c526..ba26150d578d 100644 --- a/arch/arm64/include/asm/kasan.h +++ b/arch/arm64/include/asm/kasan.h @@ -36,6 +36,10 @@ #define KASAN_SHADOW_OFFSET (KASAN_SHADOW_END - (1ULL << \ (64 - KASAN_SHADOW_SCALE_SHIFT))) +#ifdef CONFIG_KASAN_SW_TAGS +#define ARCH_SLAB_MINALIGN (1ULL << KASAN_SHADOW_SCALE_SHIFT) +#endif + void kasan_init(void); void kasan_copy_shadow(pgd_t *pgdir); asmlinkage void kasan_early_init(void); diff --git a/include/linux/slab.h b/include/linux/slab.h index 11b45f7ae405..d87f913ab4e8 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -16,6 +16,7 @@ #include <linux/overflow.h> #include <linux/types.h> #include <linux/workqueue.h> +#include <linux/kasan.h> /* diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 03d5d1374ca7..44390392d4c9 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -298,8 +298,6 @@ void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, return; } - cache->align = round_up(cache->align, KASAN_SHADOW_SCALE_SIZE); - *flags |= SLAB_KASAN; }
Instead of changing cache->align to be aligned to KASAN_SHADOW_SCALE_SIZE in kasan_cache_create() we can reuse the ARCH_SLAB_MINALIGN macro. Suggested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> --- arch/arm64/include/asm/kasan.h | 4 ++++ include/linux/slab.h | 1 + mm/kasan/common.c | 2 -- 3 files changed, 5 insertions(+), 2 deletions(-)