[PATCH 6/6] mm: kfence: replace ALIGN_DOWN(x, PAGE_SIZE) with PAGE_ALIGN_DOWN(x)

From: Muchun Song
Date: Tue Mar 28 2023 - 05:59:39 EST


Replace ALIGN_DOWN(x, PAGE_SIZE) with PAGE_ALIGN_DOWN(x) to simplify
the code a bit.

Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
---
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