[PATCH] mm: init: report kasan-tag information stored in page->flags

From: jing . xia . mail
Date: Wed Apr 15 2020 - 01:43:14 EST


From: Jing Xia <jing.xia@xxxxxxxxxx>

The pagefalgs_layout_usage shows incorrect message by means of
mminit_loglevel when Kasan runs in the mode of software tag-based
enabled with CONFIG_KASAN_SW_TAGS.
This patch corrects it and reports kasan-tag information.

Signed-off-by: Jing Xia <jing.xia@xxxxxxxxxx>
---
mm/mm_init.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/mm/mm_init.c b/mm/mm_init.c
index 7da6991..435e5f7 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -67,26 +67,30 @@ void __init mminit_verify_pageflags_layout(void)
unsigned long or_mask, add_mask;

shift = 8 * sizeof(unsigned long);
- width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH - LAST_CPUPID_SHIFT;
+ width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH
+ - LAST_CPUPID_SHIFT - KASAN_TAG_WIDTH;
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
- "Section %d Node %d Zone %d Lastcpupid %d Flags %d\n",
+ "Section %d Node %d Zone %d Lastcpupid %d Kasantag %d Flags %d\n",
SECTIONS_WIDTH,
NODES_WIDTH,
ZONES_WIDTH,
LAST_CPUPID_WIDTH,
+ KASAN_TAG_WIDTH,
NR_PAGEFLAGS);
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
- "Section %d Node %d Zone %d Lastcpupid %d\n",
+ "Section %d Node %d Zone %d Lastcpupid %d Kasantag %d\n",
SECTIONS_SHIFT,
NODES_SHIFT,
ZONES_SHIFT,
- LAST_CPUPID_SHIFT);
+ LAST_CPUPID_SHIFT,
+ KASAN_TAG_WIDTH);
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_pgshifts",
- "Section %lu Node %lu Zone %lu Lastcpupid %lu\n",
+ "Section %lu Node %lu Zone %lu Lastcpupid %lu Kasantag %lu\n",
(unsigned long)SECTIONS_PGSHIFT,
(unsigned long)NODES_PGSHIFT,
(unsigned long)ZONES_PGSHIFT,
- (unsigned long)LAST_CPUPID_PGSHIFT);
+ (unsigned long)LAST_CPUPID_PGSHIFT,
+ (unsigned long)KASAN_TAG_PGSHIFT);
mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodezoneid",
"Node/Zone ID: %lu -> %lu\n",
(unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT),
--
1.9.1