On Tue, 28 Mar 2023 at 11:59, 'Muchun Song' via kasan-dev
<kasan-dev@xxxxxxxxxxxxxxxx> wrote:
>
> Replace ALIGN_DOWN(x, PAGE_SIZE) with PAGE_ALIGN_DOWN(x) to simplify
> the code a bit.
>
> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
> ---
> mm/kfence/core.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/mm/kfence/core.c b/mm/kfence/core.c
> index f205b860f460..dbfb79a4d624 100644
> --- a/mm/kfence/core.c
> +++ b/mm/kfence/core.c
> @@ -230,17 +230,17 @@ static bool alloc_covered_contains(u32 alloc_stack_hash)
>
> static inline void kfence_protect(unsigned long addr)
> {
> - kfence_protect_page(ALIGN_DOWN(addr, PAGE_SIZE), true);
> + kfence_protect_page(PAGE_ALIGN_DOWN(addr), true);
> }
>
> static inline void kfence_unprotect(unsigned long addr)
> {
> - kfence_protect_page(ALIGN_DOWN(addr, PAGE_SIZE), false);
> + kfence_protect_page(PAGE_ALIGN_DOWN(addr), false);
> }
>
> static inline unsigned long metadata_to_pageaddr(const struct kfence_metadata *meta)
> {
> - return ALIGN_DOWN(meta->addr, PAGE_SIZE);
> + return PAGE_ALIGN_DOWN(meta->addr);
> }
>
> /*
> @@ -308,7 +308,7 @@ static inline bool check_canary_byte(u8 *addr)
> /* __always_inline this to ensure we won't do an indirect call to fn. */
> static __always_inline void for_each_canary(const struct kfence_metadata *meta, bool (*fn)(u8 *))
> {
> - const unsigned long pageaddr = ALIGN_DOWN(meta->addr, PAGE_SIZE);
> + const unsigned long pageaddr = PAGE_ALIGN_DOWN(meta->addr);
> unsigned long addr;
>
> /*
> @@ -455,7 +455,7 @@ static void kfence_guarded_free(void *addr, struct kfence_metadata *meta, bool z
> }
>
> /* Detect racy use-after-free, or incorrect reallocation of this page by KFENCE. */
> - kcsan_begin_scoped_access((void *)ALIGN_DOWN((unsigned long)addr, PAGE_SIZE), PAGE_SIZE,
> + kcsan_begin_scoped_access((void *)PAGE_ALIGN_DOWN((unsigned long)addr), PAGE_SIZE,
> KCSAN_ACCESS_SCOPED | KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ASSERT,
> &assert_page_exclusive);
>
> @@ -464,7 +464,7 @@ static void kfence_guarded_free(void *addr, struct kfence_metadata *meta, bool z
>
> /* Restore page protection if there was an OOB access. */
> if (meta->unprotected_page) {
> - memzero_explicit((void *)ALIGN_DOWN(meta->unprotected_page, PAGE_SIZE), PAGE_SIZE);
> + memzero_explicit((void *)PAGE_ALIGN_DOWN(meta->unprotected_page), PAGE_SIZE);
> kfence_protect(meta->unprotected_page);
> meta->unprotected_page = 0;
> }
> --
> 2.11.0
>
> --
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