This is a note to let you know that I've just added the patch titled
mm/huge_memory.c: warn with pr_warn_ratelimited instead of VM_WARN_ON_ONCE_FOLIO
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-huge_memory.c-warn-with-pr_warn_ratelimited-instead-of-vm_warn_on_once_folio.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4737edbbdd4958ae29ca6a310a6a2fa4e0684b01 Mon Sep 17 00:00:00 2001
From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Date: Thu, 6 Apr 2023 17:20:04 +0900
Subject: mm/huge_memory.c: warn with pr_warn_ratelimited instead of VM_WARN_ON_ONCE_FOLIO
From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
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@xxxxxxxxx
Fixes: 478d134e9506 ("mm/huge_memory: do not overkill when splitting huge_zero_page")
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Reported-by: syzbot+07a218429c8d19b1fb25@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://lore.kernel.org/lkml/000000000000a6f34a05e6efcd01@xxxxxxxxxx/
Reviewed-by: Yang Shi <shy828301@xxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Xu Yu <xuyu@xxxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2655,9 +2655,10 @@ int split_huge_page_to_list(struct page
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;
Patches currently in stable-queue which might be from naoya.horiguchi@xxxxxxx are
queue-6.1/mm-huge_memory.c-warn-with-pr_warn_ratelimited-instead-of-vm_warn_on_once_folio.patch
