diff options
| author | Andrey Konovalov | 2022-03-24 18:10:43 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2022-03-24 19:06:46 -0700 |
| commit | e9d0ca9228162f5442b751edf8c9721b15dcfa1e (patch) | |
| tree | 953a159a1d96cfa643f95c5e672cacd1c4533bdb | |
| parent | 7e3cbba65de22f20ad18a2de09f65238bfe84c5b (diff) | |
kasan, page_alloc: rework kasan_unpoison_pages call site
Rework the checks around kasan_unpoison_pages() call in post_alloc_hook().
The logical condition for calling this function is:
- If a software KASAN mode is enabled, we need to mark shadow memory.
- Otherwise, HW_TAGS KASAN is enabled, and it only makes sense to set
tags if they haven't already been cleared by tag_clear_highpage(),
which is indicated by init_tags.
This patch concludes the changes for post_alloc_hook().
Link: https://lkml.kernel.org/r/0ecebd0d7ccd79150e3620ea4185a32d3dfe912f.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/page_alloc.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 386898f1a7c3..350bb27dc4bb 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2382,15 +2382,20 @@ inline void post_alloc_hook(struct page *page, unsigned int order, /* Note that memory is already initialized by the loop above. */ init = false; } - if (kasan_has_integrated_init()) { - if (!init_tags) { - kasan_unpoison_pages(page, order, init); + /* + * If either a software KASAN mode is enabled, or, + * in the case of hardware tag-based KASAN, + * if memory tags have not been cleared via tag_clear_highpage(). + */ + if (IS_ENABLED(CONFIG_KASAN_GENERIC) || + IS_ENABLED(CONFIG_KASAN_SW_TAGS) || + kasan_hw_tags_enabled() && !init_tags) { + /* Mark shadow memory or set memory tags. */ + kasan_unpoison_pages(page, order, init); - /* Note that memory is already initialized by KASAN. */ + /* Note that memory is already initialized by KASAN. */ + if (kasan_has_integrated_init()) init = false; - } - } else { - kasan_unpoison_pages(page, order, init); } /* If memory is still not initialized, do it now. */ if (init) |