mm, kasan: use KASAN_TAG_KERNEL instead of 0xff

Use the KASAN_TAG_KERNEL marco instead of open-coding 0xff in the mm code.
This macro is provided by include/linux/kasan-tags.h, which does not
include any other headers, so it's safe to include it into mm.h without
causing circular include dependencies.

Link: https://lkml.kernel.org/r/71db9087b0aebb6c4dccbc609cc0cd50621533c7.1703188911.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Andrey Konovalov 2023-12-21 21:04:44 +01:00 committed by Andrew Morton
parent 27232ba96c
commit 5cb6674b69
3 changed files with 4 additions and 3 deletions

View File

@ -4,6 +4,7 @@
#include <linux/bug.h>
#include <linux/kasan-enabled.h>
#include <linux/kasan-tags.h>
#include <linux/kernel.h>
#include <linux/static_key.h>
#include <linux/types.h>

View File

@ -1815,7 +1815,7 @@ static inline void vma_set_access_pid_bit(struct vm_area_struct *vma)
static inline u8 page_kasan_tag(const struct page *page)
{
u8 tag = 0xff;
u8 tag = KASAN_TAG_KERNEL;
if (kasan_enabled()) {
tag = (page->flags >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK;
@ -1844,7 +1844,7 @@ static inline void page_kasan_tag_set(struct page *page, u8 tag)
static inline void page_kasan_tag_reset(struct page *page)
{
if (kasan_enabled())
page_kasan_tag_set(page, 0xff);
page_kasan_tag_set(page, KASAN_TAG_KERNEL);
}
#else /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */

View File

@ -1059,7 +1059,7 @@ static inline bool should_skip_kasan_poison(struct page *page, fpi_t fpi_flags)
if (IS_ENABLED(CONFIG_KASAN_GENERIC))
return deferred_pages_enabled();
return page_kasan_tag(page) == 0xff;
return page_kasan_tag(page) == KASAN_TAG_KERNEL;
}
static void kernel_init_pages(struct page *page, int numpages)