From: Michal Hocko <mhocko@suse.com>
To: Barry Song <21cnbao@gmail.com>
Cc: akpm@linux-foundation.org, linux-mm@kvack.org,
Barry Song <v-songbaohua@oppo.com>,
Uladzislau Rezki <urezki@gmail.com>,
Christoph Hellwig <hch@infradead.org>,
Lorenzo Stoakes <lstoakes@gmail.com>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Vlastimil Babka <vbabka@suse.cz>,
Roman Gushchin <roman.gushchin@linux.dev>,
Hyeonggon Yoo <42.hyeyoo@gmail.com>
Subject: Re: [PATCH RFC] mm: warn potential return NULL for kmalloc_array and kvmalloc_array with __GFP_NOFAIL
Date: Fri, 19 Jul 2024 13:19:29 +0200 [thread overview]
Message-ID: <ZppLwVtVHMxPhxpe@tiehlicka> (raw)
In-Reply-To: <CAGsJ_4wxsMRJ7bLeaFaoWcjk=FszWrEiDM-3+kV9K=CMeGpeSA@mail.gmail.com>
On Fri 19-07-24 23:05:48, Barry Song wrote:
[...]
> BTW, we are really exposing potential exploits. Rather than an early
> stage BUG_ON(), is it reasonable to BUG_ON when we really return
> NULL for NOFAIL at the last moment? This will crash the system but it
> is still safer than exposing exploits.
I believe the whole discssion here revolves around either using BUG_ON
or retrying without any sleep. But I guess you are specifically talking
about those two original k[v]malloc_array* interfaces which have
introduced the early break. For those BUG_ON is a safer option than
WARN_ON definitely. Please involve Kees who has introduced those.
kvmalloc_node_noprof would require something similar. It checks for
INT_MAX. You can test whether Linus is OK with such a change that way ;)
Good luck
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2024-07-19 11:19 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-17 23:00 [PATCH RFC] mm: warn potential return NULL for kmalloc_array and kvmalloc_array with __GFP_NOFAIL Barry Song
2024-07-18 6:58 ` Michal Hocko
2024-07-18 7:04 ` Christoph Hellwig
2024-07-18 7:12 ` Michal Hocko
2024-07-18 8:16 ` Vlastimil Babka
2024-07-18 7:22 ` Barry Song
2024-07-18 7:27 ` Michal Hocko
2024-07-18 7:41 ` Barry Song
2024-07-18 7:53 ` Michal Hocko
2024-07-18 8:18 ` Barry Song
2024-07-18 8:32 ` Michal Hocko
2024-07-18 8:43 ` Barry Song
2024-07-18 8:50 ` Michal Hocko
2024-07-19 0:35 ` Barry Song
2024-07-19 7:02 ` Michal Hocko
2024-07-19 7:07 ` Barry Song
2024-07-19 7:42 ` Michal Hocko
2024-07-19 7:51 ` Barry Song
2024-07-19 8:01 ` Michal Hocko
2024-07-19 8:28 ` Barry Song
2024-07-19 8:40 ` Michal Hocko
2024-07-19 9:36 ` Barry Song
2024-07-19 9:45 ` Michal Hocko
2024-07-19 9:58 ` Barry Song
2024-07-19 10:57 ` Michal Hocko
2024-07-19 11:05 ` Barry Song
2024-07-19 11:19 ` Michal Hocko [this message]
2024-07-19 8:50 ` Vlastimil Babka
2024-07-19 9:33 ` Michal Hocko
2024-07-19 10:10 ` Vlastimil Babka
2024-07-19 10:52 ` Michal Hocko
2024-07-19 11:13 ` Vlastimil Babka
2024-07-19 11:26 ` Michal Hocko
2024-07-19 13:02 ` Barry Song
2024-07-19 13:30 ` Michal Hocko
2024-07-20 0:36 ` Barry Song
2024-07-22 7:23 ` Michal Hocko
2024-07-22 7:34 ` Vlastimil Babka
2024-07-19 7:37 ` Christoph Hellwig
2024-07-19 7:43 ` Barry Song
2024-07-19 7:53 ` Christoph Hellwig
2024-07-20 22:14 ` Barry Song
2024-07-22 7:26 ` Michal Hocko
2024-07-22 8:09 ` Barry Song
2024-07-22 9:01 ` Michal Hocko
2024-07-22 23:18 ` Christoph Hellwig
2024-07-22 23:22 ` Barry Song
2024-07-19 8:35 ` Vlastimil Babka
2024-07-18 7:48 ` Hailong Liu
2024-07-18 8:33 ` Barry Song
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