summary refs log tree commit diff
path: root/mm
diff options
context:
space:
mode:
authorNaoya Horiguchi <naoya.horiguchi@nec.com>2023-04-06 17:20:04 +0900
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-04-26 14:28:41 +0200
commite8a7bdb6f76cdaef4183669554ad76e5ed197d92 (patch)
tree96acd846c54189d9d24321a57d707547c5335917 /mm
parent519dbe737f0d26b2c34a1f3990bf27dd82d3778d (diff)
downloadlinux-e8a7bdb6f76cdaef4183669554ad76e5ed197d92.tar.gz
mm/huge_memory.c: warn with pr_warn_ratelimited instead of VM_WARN_ON_ONCE_FOLIO
commit 4737edbbdd4958ae29ca6a310a6a2fa4e0684b01 upstream.

split_huge_page_to_list() WARNs when called for huge zero pages, which
sounds to me too harsh because it does not imply a kernel bug, but just
notifies the event to admins.  On the other hand, this is considered as
critical by syzkaller and makes its testing less efficient, which seems to
me harmful.

So replace the VM_WARN_ON_ONCE_FOLIO with pr_warn_ratelimited.

Link: https://lkml.kernel.org/r/20230406082004.2185420-1-naoya.horiguchi@linux.dev
Fixes: 478d134e9506 ("mm/huge_memory: do not overkill when splitting huge_zero_page")
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reported-by: syzbot+07a218429c8d19b1fb25@syzkaller.appspotmail.com
  Link: https://lore.kernel.org/lkml/000000000000a6f34a05e6efcd01@google.com/
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Xu Yu <xuyu@linux.alibaba.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/huge_memory.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index cfe8d77af7ab..b20fef29e5bb 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2655,9 +2655,10 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
 	VM_BUG_ON_FOLIO(!folio_test_large(folio), folio);
 
 	is_hzp = is_huge_zero_page(&folio->page);
-	VM_WARN_ON_ONCE_FOLIO(is_hzp, folio);
-	if (is_hzp)
+	if (is_hzp) {
+		pr_warn_ratelimited("Called split_huge_page for huge zero page\n");
 		return -EBUSY;
+	}
 
 	if (folio_test_writeback(folio))
 		return -EBUSY;