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@xxxxxxxxxx> 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
