From: Muchun Song <songmuchun@bytedance.com>
To: Wang Qing <wangqing@vivo.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Linux Memory Management List <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [Phishing Risk] [External] [PATCH] mm: add GFP_ATOMIC flag after local_lock_irqsave
Date: Tue, 6 Jul 2021 10:32:56 +0800 [thread overview]
Message-ID: <CAMZfGtUbX+TAx-7RJ4ZpoNLHDa9mp6k+DBqHaYiLjhSJokh3Sw@mail.gmail.com> (raw)
In-Reply-To: <1625493432-9945-1-git-send-email-wangqing@vivo.com>
On Mon, Jul 5, 2021 at 9:57 PM Wang Qing <wangqing@vivo.com> wrote:
>
> Use GFP_ATOMIC when local_lock_irqsave in __alloc_pages_bulk
>
> Reported-by: syzbot+e45919db2eab5e837646@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, 0);
Hi Wang Qing,
I didn't get the point here. IIUC, prep_new_page() will not allocate
memory. So why do we need GFP_ATOMIC? What I missed here?
Thanks.
> if (page_list)
> list_add(&page->lru, page_list);
> else
> --
> 2.7.4
>
next prev parent reply other threads:[~2021-07-06 2:33 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-05 13:57 [PATCH] mm: add GFP_ATOMIC flag after local_lock_irqsave Wang Qing
2021-07-06 2:32 ` Muchun Song [this message]
2021-07-06 2:41 ` Re:Re: [Phishing Risk] [External] " 王擎
2021-07-06 3:05 ` Muchun Song
2021-07-06 3:13 ` 王擎
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