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charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Stat-Signature: xbjqhuheofp37kujateeujsdcj66twyr X-Rspamd-Queue-Id: D3A75180003 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1761768577-213185 X-HE-Meta: U2FsdGVkX19Sd5jO/yFw9rpNGXtrFB41qUbvpIHyewtVXTdjCKq6kBPxG+k2fVYI2MngYb19ouhzAyijbwyqc8QSgRNGtjwjTe2H3UrIazv7zHeL8VEFrC7MjCDDloSXTpHeAzx84mzAgDC4SkS0DYTqRd12hmajWAATE2Xl9KYNVu9MgszJXyFdq/fHB+SfqIrSm0McMqO6JHGvdE3Zr0yYOnw3oM7OqyGAiN1FHw5XepqWjlUxtc3mkfDOOr1mSMiklyW7FYbYMJqOz0m3FUpiG+KvbVY52vdRF6ZkGL3APLjPiGcRj6KZCEGpFA+w2X2CT7+MIoHN/jbcsZc5QSvkHr5n2fAPpCvEA1rHNuldbtAWrjQ44DzO2FQwfYaU6UBUKOx0Ku+vS7kFLn9TRrrLgg91dlfHcmTsFu+IJvMISNjPT+z2S7nBZpJACwfscdAsQAE3Bduwa40bZHESbpw6+Z3IjLC8ToZr76ga1m9LtNi5yFdGffohAoZrXxN1piVWqhQNkGtkTB7KgGSz7NGsrSHcZvstm6mnPgHR9cpjeLiyyKLYFScbVLMl+e2NAguWsvdUfks1rQPr02kCkZ1dDi5fmILEEbBRWaEAapDJE0/r4/G3OksruE5YtFLQ70r5c8xkOhMvq4ST2DA/A92de4AxzQ8Yu8WTsHtCvtmpc7d+cQs3H1NfK5dNB121OzY4Uh3jJhQrrgdDYeFxsqnU2B9+QW4zytNpPGRvEQzqlfwcbEN9mduK08GHpQt1z9v4iWHYeWpLI6atUuits5TZOtVOqd1CYo9yhdwNTH8MQA8OEMfl3Dfn2Gn2QcdEJsQfy8qx/uRA8G+L3shLBojtyjwdcRIgMZbtJFlrL/fHvXZsohrnvcZjDowzWncZhOfMXvdKpp/a0cbhKccAoCY8w0GDUL/Kkh2UuOBW1YidfqxE/ASMnWcX7sdq1WJ+BrcPJpOjgXqSkkcZieV ZkQBjNaC iNRGgi0tG7Ak9PP+h94kVHZ8DW9xUd3N7VyZOfAVP43f55csfjoXAOtjQiMd2iMLrGk2XheQLx513OS3rgnT2BgkYJ20DAmzq8qWyuDnPR05HSQwRJRvf7bpJSybDZLmHd3awzIhZpXcg5CPFwGiR+3nlQMf/yrOrSw3vceN4d1hqAlK6YUQmdLPozFapoQGIGuLRge8w+O5gT2D3Ock2XtYar3H2fQkSKMvbCf4kqwuDJPehywTMQ5oxEwjzgveRg63d1KSFehNx/f6Nljggthqd2U61Ulpr+06w1hsDglb1NlLFmBxD3v3MmIvF3GZL+bW2IjXfsBf6ZcE= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Maciej Wieczor-Retman 8 byte minimal SLAB alignment interferes with KASAN's granularity of 16 bytes. It causes a lot of out-of-bounds errors for unaligned 8 byte allocations. Compared to a kernel with KASAN disabled, the memory footprint increases because all kmalloc-8 allocations now are realized as kmalloc-16, which has twice the object size. But more meaningfully, when compared to a kernel with generic KASAN enabled, there is no difference. Because of redzones in generic KASAN, kmalloc-8' and kmalloc-16' object size is the same (48 bytes). So changing the minimal SLAB alignment of the tag-based mode doesn't have any negative impact when compared to the other software KASAN mode. Adjust x86 minimal SLAB alignment to match KASAN granularity size. Signed-off-by: Maciej Wieczor-Retman Reviewed-by: Andrey Konovalov --- Changelog v6: - Add Andrey's Reviewed-by tag. Changelog v4: - Extend the patch message with some more context and impact information. Changelog v3: - Fix typo in patch message 4 -> 16. - Change define location to arch/x86/include/asm/cache.c. arch/x86/include/asm/cache.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/include/asm/cache.h b/arch/x86/include/asm/cache.h index 69404eae9983..3232583b5487 100644 --- a/arch/x86/include/asm/cache.h +++ b/arch/x86/include/asm/cache.h @@ -21,4 +21,8 @@ #endif #endif =20 +#ifdef CONFIG_KASAN_SW_TAGS +#define ARCH_SLAB_MINALIGN (1ULL << KASAN_SHADOW_SCALE_SHIFT) +#endif + #endif /* _ASM_X86_CACHE_H */ --=20 2.51.0