From: Vlastimil Babka <vbabka@suse.cz>
To: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
Barry Song <21cnbao@gmail.com>,
akpm@linux-foundation.org, linux-mm@kvack.org
Cc: 42.hyeyoo@gmail.com, cl@linux.com, hailong.liu@oppo.com,
hch@infradead.org, iamjoonsoo.kim@lge.com, lstoakes@gmail.com,
mhocko@suse.com, penberg@kernel.org, rientjes@google.com,
roman.gushchin@linux.dev, torvalds@linux-foundation.org,
urezki@gmail.com, v-songbaohua@oppo.com,
virtualization@lists.linux.dev, Kees Cook <kees@kernel.org>
Subject: Re: [PATCH v2 3/4] mm: BUG_ON to avoid NULL deference while __GFP_NOFAIL fails
Date: Wed, 31 Jul 2024 12:48:29 +0200 [thread overview]
Message-ID: <c20ea16c-e717-4bf1-92f4-cb5338d4406a@suse.cz> (raw)
In-Reply-To: <9f1d0f2b-ee22-48b7-ba60-d7b886572670@I-love.SAKURA.ne.jp>
On 7/31/24 12:44 PM, Tetsuo Handa wrote:
> On 2024/07/31 19:29, Vlastimil Babka wrote:
>>> @@ -827,8 +827,10 @@ kvmalloc_array_node_noprof(size_t n, size_t size, gfp_t flags, int node)
>>> {
>>> size_t bytes;
>>>
>>> - if (unlikely(check_mul_overflow(n, size, &bytes)))
>>> + if (unlikely(check_mul_overflow(n, size, &bytes))) {
>>> + BUG_ON(flags & __GFP_NOFAIL);
>>
>> Shouldn't we produce some kind of warning also in the no-NOFAIL case?
>> Returning a NULL completely silently feels wrong.
>
> Doesn't embedding macros like BUG_ON() into inline functions needlessly bloat
> the kernel size? I think we can call a non-inlined function (that is marked
> as EXPORT_SYMBOL()) for emitting warning.
Hm yeah we could probably make the whole function non-inline as it results
in a call anyway.
next prev parent reply other threads:[~2024-07-31 10:48 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-31 0:01 [PATCH v2 0/4] mm: clarify nofail memory allocation Barry Song
2024-07-31 0:01 ` [PATCH RFT v2 1/4] vpda: try to fix the potential crash due to misusing __GFP_NOFAIL Barry Song
2024-07-31 3:09 ` Jason Wang
2024-07-31 3:15 ` Barry Song
2024-07-31 3:58 ` Jason Wang
2024-07-31 4:11 ` Barry Song
2024-07-31 4:13 ` Jason Wang
2024-07-31 5:05 ` Barry Song
2024-07-31 10:20 ` Tetsuo Handa
2024-08-01 2:37 ` Jason Wang
2024-08-05 1:32 ` Barry Song
2024-08-05 8:19 ` Jason Wang
2024-08-01 2:30 ` Jason Wang
2024-07-31 0:01 ` [PATCH v2 2/4] mm: Document __GFP_NOFAIL must be blockable Barry Song
2024-07-31 10:18 ` Vlastimil Babka
2024-07-31 16:26 ` Christoph Hellwig
2024-07-31 0:01 ` [PATCH v2 3/4] mm: BUG_ON to avoid NULL deference while __GFP_NOFAIL fails Barry Song
2024-07-31 7:11 ` Michal Hocko
2024-07-31 10:29 ` Vlastimil Babka
2024-07-31 10:44 ` Tetsuo Handa
2024-07-31 10:48 ` Vlastimil Babka [this message]
2024-07-31 10:57 ` Barry Song
2024-07-31 16:28 ` Christoph Hellwig
2024-07-31 0:01 ` [PATCH v2 4/4] mm: prohibit NULL deference exposed for unsupported non-blockable __GFP_NOFAIL Barry Song
2024-07-31 7:15 ` Michal Hocko
2024-07-31 10:55 ` Vlastimil Babka
2024-07-31 11:08 ` Barry Song
2024-07-31 11:31 ` Michal Hocko
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