lkml.org 
[lkml]   [2021]   [Jul]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH V2] mm: add GFP_ATOMIC flag after local_lock_irqsave
Date
prep_new_page() will allocate memory in some scenarios. 

Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:96
___might_sleep.cold+0x1f1/0x237 kernel/sched/core.c:9153
prepare_alloc_pages+0x3da/0x580 mm/page_alloc.c:5179
__alloc_pages+0x12f/0x500 mm/page_alloc.c:5375
alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2272
stack_depot_save+0x39d/0x4e0 lib/stackdepot.c:303
save_stack+0x15e/0x1e0 mm/page_owner.c:120
__set_page_owner+0x50/0x290 mm/page_owner.c:181
prep_new_page mm/page_alloc.c:2445 [inline]
__alloc_pages_bulk+0x8b9/0x1870 mm/page_alloc.c:5313

So we add GFP_ATOMIC and remove GFP_KERNEL flag.

Reported-and-tested-by: syzbot+b07d8440edb5f8988eea@syzkaller.appspotmail.com
Signed-off-by: Wang Qing <wangqing@vivo.com>
---
mm/page_alloc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d6e94cc..3016ba5
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5309,7 +5309,7 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
}
nr_account++;

- prep_new_page(page, 0, gfp, 0);
+ prep_new_page(page, 0, gfp | GFP_ATOMIC & ~GFP_KERNEL, 0);
if (page_list)
list_add(&page->lru, page_list);
else
--
2.7.4
\
 
 \ /
  Last update: 2021-07-06 11:26    [W:0.033 / U:0.204 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site