From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Add a clear_highpage_tagged() helper that does clear_highpage() on a
page potentially tagged by KASAN.
This helper is used by the following patch.
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
---
include/linux/highmem.h | 11 +++++++++++
mm/page_alloc.c | 8 ++------
2 files changed, 13 insertions(+), 6 deletions(-)
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 3af34de54330..df76a0db7cec 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -243,6 +243,17 @@ static inline void clear_highpage(struct page *page)
kunmap_local(kaddr);
}
+static inline void clear_highpage_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 66ef8c310dce..d82ea983a7a3 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_tagged(page + i);
kasan_enable_current();
}
--
2.25.1
