From: Andrey Konovalov Date: Thu, 9 Jun 2022 18:18:46 +0000 (+0200) Subject: mm: introduce clear_highpage_kasan_tagged X-Git-Tag: v6.6.17~6873^2~237 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d9da8f6cf55eeca642c021912af1890002464c64;p=platform%2Fkernel%2Flinux-rpi.git mm: introduce clear_highpage_kasan_tagged Add a clear_highpage_kasan_tagged() helper that does clear_highpage() on a page potentially tagged by KASAN. This helper is used by the following patch. Link: https://lkml.kernel.org/r/4471979b46b2c487787ddcd08b9dc5fedd1b6ffd.1654798516.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Marco Elver Signed-off-by: Andrew Morton --- diff --git a/include/linux/highmem.h b/include/linux/highmem.h index fee9835e3793..22379a63e293 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -243,6 +243,16 @@ static inline void clear_highpage(struct page *page) kunmap_local(kaddr); } +static inline void clear_highpage_kasan_tagged(struct page *page) +{ + u8 tag; + + tag = page_kasan_tag(page); + page_kasan_tag_reset(page); + clear_highpage(page); + page_kasan_tag_set(page, tag); +} + #ifndef __HAVE_ARCH_TAG_CLEAR_HIGHPAGE static inline void tag_clear_highpage(struct page *page) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 9234863f2488..248469134962 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1302,12 +1302,8 @@ static void kernel_init_pages(struct page *page, int numpages) /* s390's use of memset() could override KASAN redzones. */ kasan_disable_current(); - for (i = 0; i < numpages; i++) { - u8 tag = page_kasan_tag(page + i); - page_kasan_tag_reset(page + i); - clear_highpage(page + i); - page_kasan_tag_set(page + i, tag); - } + for (i = 0; i < numpages; i++) + clear_highpage_kasan_tagged(page + i); kasan_enable_current(); }