diff options
| author | Will Deacon <will@kernel.org> | 2022-07-25 10:57:08 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2022-07-25 10:57:08 +0100 |
| commit | c436500d9f03ecaf791674046e25ba85a1176454 (patch) | |
| tree | c93c44d166f232c7316899dbbba39e65f0bc3751 /mm | |
| parent | 03939cf0d5d5eaf4141c594e427eb5ba14fbcd91 (diff) | |
| parent | 20794545c14692094a882d2221c251c4573e6adf (diff) | |
Merge branch 'for-next/mte' into for-next/core
* for-next/mte:
arm64: kasan: Revert "arm64: mte: reset the page tag in page->flags"
mm: kasan: Skip page unpoisoning only if __GFP_SKIP_KASAN_UNPOISON
mm: kasan: Skip unpoisoning of user pages
mm: kasan: Ensure the tags are visible before the tag in page->flags
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/kasan/common.c | 3 | ||||
| -rw-r--r-- | mm/page_alloc.c | 19 |
2 files changed, 12 insertions, 10 deletions
diff --git a/mm/kasan/common.c b/mm/kasan/common.c index c40c0e7b3b5f..78be2beb7453 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -108,9 +108,10 @@ void __kasan_unpoison_pages(struct page *page, unsigned int order, bool init) return; tag = kasan_random_tag(); + kasan_unpoison(set_tag(page_address(page), tag), + PAGE_SIZE << order, init); for (i = 0; i < (1 << order); i++) page_kasan_tag_set(page + i, tag); - kasan_unpoison(page_address(page), PAGE_SIZE << order, init); } void __kasan_poison_pages(struct page *page, unsigned int order, bool init) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e008a3df0485..bf45a6aa407a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2361,7 +2361,7 @@ static inline bool check_new_pcp(struct page *page, unsigned int order) } #endif /* CONFIG_DEBUG_VM */ -static inline bool should_skip_kasan_unpoison(gfp_t flags, bool init_tags) +static inline bool should_skip_kasan_unpoison(gfp_t flags) { /* Don't skip if a software KASAN mode is enabled. */ if (IS_ENABLED(CONFIG_KASAN_GENERIC) || @@ -2373,12 +2373,10 @@ static inline bool should_skip_kasan_unpoison(gfp_t flags, bool init_tags) return true; /* - * With hardware tag-based KASAN enabled, skip if either: - * - * 1. Memory tags have already been cleared via tag_clear_highpage(). - * 2. Skipping has been requested via __GFP_SKIP_KASAN_UNPOISON. + * With hardware tag-based KASAN enabled, skip if this has been + * requested via __GFP_SKIP_KASAN_UNPOISON. */ - return init_tags || (flags & __GFP_SKIP_KASAN_UNPOISON); + return flags & __GFP_SKIP_KASAN_UNPOISON; } static inline bool should_skip_init(gfp_t flags) @@ -2397,6 +2395,7 @@ inline void post_alloc_hook(struct page *page, unsigned int order, bool init = !want_init_on_free() && want_init_on_alloc(gfp_flags) && !should_skip_init(gfp_flags); bool init_tags = init && (gfp_flags & __GFP_ZEROTAGS); + int i; set_page_private(page, 0); set_page_refcounted(page); @@ -2422,8 +2421,6 @@ inline void post_alloc_hook(struct page *page, unsigned int order, * should be initialized as well). */ if (init_tags) { - int i; - /* Initialize both memory and tags. */ for (i = 0; i != 1 << order; ++i) tag_clear_highpage(page + i); @@ -2431,13 +2428,17 @@ inline void post_alloc_hook(struct page *page, unsigned int order, /* Note that memory is already initialized by the loop above. */ init = false; } - if (!should_skip_kasan_unpoison(gfp_flags, init_tags)) { + if (!should_skip_kasan_unpoison(gfp_flags)) { /* Unpoison shadow memory or set memory tags. */ kasan_unpoison_pages(page, order, init); /* Note that memory is already initialized by KASAN. */ if (kasan_has_integrated_init()) init = false; + } else { + /* Ensure page_address() dereferencing does not fault. */ + for (i = 0; i != 1 << order; ++i) + page_kasan_tag_reset(page + i); } /* If memory is still not initialized, do it now. */ if (init) |