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.
