From: Linus Torvalds <torvalds@linux-foundation.org>
To: Michal Hocko <mhocko@suse.com>
Cc: "David Hildenbrand" <david@redhat.com>,
"Barry Song" <21cnbao@gmail.com>,
akpm@linux-foundation.org, linux-mm@kvack.org,
42.hyeyoo@gmail.com, cl@linux.com, hailong.liu@oppo.com,
hch@infradead.org, iamjoonsoo.kim@lge.com, penberg@kernel.org,
rientjes@google.com, roman.gushchin@linux.dev, urezki@gmail.com,
v-songbaohua@oppo.com, vbabka@suse.cz,
virtualization@lists.linux.dev, "Christoph Hellwig" <hch@lst.de>,
"Lorenzo Stoakes" <lorenzo.stoakes@oracle.com>,
"Kees Cook" <kees@kernel.org>,
"Eugenio Pérez" <eperezma@redhat.com>,
"Jason Wang" <jasowang@redhat.com>,
"Maxime Coquelin" <maxime.coquelin@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Xuan Zhuo" <xuanzhuo@linux.alibaba.com>
Subject: Re: [PATCH v3 3/4] mm: BUG_ON to avoid NULL deference while __GFP_NOFAIL fails
Date: Mon, 19 Aug 2024 10:17:23 -0700 [thread overview]
Message-ID: <CAHk-=wjaV+jNdKh26ZEkzRcpbxQCzZbPMsWn1+AM-tCxc6s44w@mail.gmail.com> (raw)
In-Reply-To: <ZsN9Eo8HWdEgqpf3@tiehlicka>
On Mon, 19 Aug 2024 at 10:12, Michal Hocko <mhocko@suse.com> wrote:
>
> Whether to BUG_ON or simply loop for ever in the allocator if somebody
> requests non-sleeping NOFAIL allocation is a different story.
Just return NULL.
The bug isn't in the VM. It's in the caller. Don't take on other
peoples problems.
It was never valid to say "I want to allocate lots of memory and you
can't fail".
Don't validate that kind of bogus behavior, just tell them "you're
bad" and return NULL.
Linus
next prev parent reply other threads:[~2024-08-19 17:17 UTC|newest]
Thread overview: 101+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-17 6:24 [PATCH v3 0/4] mm: clarify nofail memory allocation Barry Song
2024-08-17 6:24 ` [PATCH v3 1/4] vduse: avoid using __GFP_NOFAIL Barry Song
2024-08-17 6:24 ` [PATCH v3 2/4] mm: document __GFP_NOFAIL must be blockable Barry Song
2024-08-17 6:24 ` [PATCH v3 3/4] mm: BUG_ON to avoid NULL deference while __GFP_NOFAIL fails Barry Song
2024-08-19 9:43 ` David Hildenbrand
2024-08-19 9:47 ` Barry Song
2024-08-19 9:55 ` David Hildenbrand
2024-08-19 10:02 ` Barry Song
2024-08-19 12:33 ` David Hildenbrand
2024-08-19 12:48 ` Barry Song
2024-08-19 12:49 ` David Hildenbrand
2024-08-19 17:12 ` Michal Hocko
2024-08-19 17:17 ` Linus Torvalds [this message]
2024-08-19 20:24 ` David Hildenbrand
2024-08-19 20:35 ` Linus Torvalds
2024-08-19 21:57 ` David Hildenbrand
2024-08-19 22:13 ` Linus Torvalds
2024-08-20 6:17 ` Michal Hocko
2024-08-19 12:49 ` Christoph Hellwig
2024-08-19 12:51 ` David Hildenbrand
2024-08-19 12:53 ` Christoph Hellwig
2024-08-19 13:14 ` David Hildenbrand
2024-08-19 13:05 ` Barry Song
2024-08-19 13:10 ` David Hildenbrand
2024-08-19 13:19 ` Barry Song
2024-08-19 13:22 ` David Hildenbrand
2024-08-17 6:24 ` [PATCH v3 4/4] mm: prohibit NULL deference exposed for unsupported non-blockable __GFP_NOFAIL Barry Song
2024-08-18 2:55 ` Yafang Shao
2024-08-18 3:48 ` Barry Song
2024-08-18 5:51 ` Yafang Shao
2024-08-18 6:27 ` Barry Song
2024-08-18 6:45 ` Barry Song
2024-08-18 7:07 ` Yafang Shao
2024-08-18 7:25 ` Barry Song
2024-08-19 7:51 ` Michal Hocko
2024-08-19 7:50 ` Michal Hocko
2024-08-19 9:25 ` Yafang Shao
2024-08-19 9:39 ` Barry Song
2024-08-19 9:45 ` Yafang Shao
2024-08-19 10:10 ` Barry Song
2024-08-19 11:56 ` Yafang Shao
2024-08-19 12:09 ` Michal Hocko
2024-08-19 12:17 ` Yafang Shao
2024-08-19 14:01 ` Michal Hocko
2024-08-19 10:17 ` Michal Hocko
2024-08-19 11:56 ` Yafang Shao
2024-08-19 12:04 ` Michal Hocko
2024-08-19 9:44 ` David Hildenbrand
2024-08-19 10:19 ` Michal Hocko
2024-08-19 12:48 ` David Hildenbrand
2024-08-19 13:02 ` [PATCH v3 0/4] mm: clarify nofail memory allocation David Hildenbrand
2024-08-19 16:05 ` Linus Torvalds
2024-08-19 19:23 ` Barry Song
2024-08-19 19:33 ` Linus Torvalds
2024-08-19 21:48 ` Barry Song
2024-08-20 6:24 ` Michal Hocko
2024-08-21 12:40 ` Yafang Shao
2024-08-21 22:59 ` Linus Torvalds
2024-08-22 6:21 ` Michal Hocko
2024-08-22 6:40 ` Linus Torvalds
2024-08-22 6:56 ` Linus Torvalds
2024-08-22 7:47 ` Michal Hocko
2024-08-22 7:57 ` Barry Song
2024-08-22 8:24 ` Michal Hocko
2024-08-22 8:39 ` David Hildenbrand
2024-08-22 9:08 ` Linus Torvalds
2024-08-22 9:16 ` Michal Hocko
2024-08-22 9:24 ` Linus Torvalds
2024-08-22 9:11 ` Michal Hocko
2024-08-22 9:18 ` Linus Torvalds
2024-08-22 9:33 ` Michal Hocko
2024-08-22 9:44 ` Linus Torvalds
2024-08-22 9:59 ` Michal Hocko
2024-08-22 10:30 ` Linus Torvalds
2024-08-22 10:46 ` Michal Hocko
2024-08-22 9:27 ` David Hildenbrand
2024-08-22 9:34 ` Linus Torvalds
2024-08-22 9:43 ` David Hildenbrand
2024-08-22 9:53 ` Linus Torvalds
2024-08-22 11:58 ` Johannes Weiner
2024-08-26 12:10 ` Vlastimil Babka
2024-08-27 6:57 ` Linus Torvalds
2024-08-27 7:15 ` Barry Song
2024-08-27 7:38 ` Vlastimil Babka
2024-08-27 7:50 ` Barry Song
2024-08-29 10:24 ` Vlastimil Babka
2024-08-29 11:53 ` Barry Song
2024-08-29 13:20 ` Michal Hocko
2024-08-29 21:27 ` Barry Song
2024-08-29 22:31 ` Barry Song
2024-08-30 7:24 ` Michal Hocko
2024-08-30 7:37 ` Vlastimil Babka
2024-08-22 9:41 ` Michal Hocko
2024-08-22 9:42 ` David Hildenbrand
2024-08-22 7:01 ` Gao Xiang
2024-08-22 7:54 ` Michal Hocko
2024-08-22 8:04 ` Gao Xiang
2024-08-22 14:35 ` Yafang Shao
2024-08-22 15:02 ` Gao Xiang
2024-08-22 6:37 ` Barry Song
2024-08-22 14:22 ` Yafang Shao
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