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From: Kees Cook <keescook@chromium.org>
To: Michal Hocko <mhocko@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Vlastimil Babka <vbabka@suse.cz>,
	David Rientjes <rientjes@google.com>,
	Mel Gorman <mgorman@suse.de>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Al Viro <viro@zeniv.linux.org.uk>, Linux-MM <linux-mm@kvack.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Michal Hocko <mhocko@suse.com>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	Anton Vorontsov <anton@enomsg.org>,
	Colin Cross <ccross@android.com>, Tony Luck <tony.luck@intel.com>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Ben Skeggs <bskeggs@redhat.com>,
	Kent Overstreet <kent.overstreet@gmail.com>,
	Santosh Raspatur <santosh@chelsio.com>,
	Hariprasad S <hariprasad@chelsio.com>,
	Yishai Hadas <yishaih@mellanox.com>,
	Oleg Drokin <oleg.drokin@intel.com>,
	"Yan, Zheng" <zyan@redhat.com>,
	Alexei Starovoitov <ast@kernel.org>,
	Eric Dumazet <eric.dumazet@gmail.com>,
	Network Development <netdev@vger.kernel.org>
Subject: Re: [PATCH 5/9] treewide: use kv[mz]alloc* rather than opencoded variants
Date: Mon, 30 Jan 2017 11:24:02 -0800	[thread overview]
Message-ID: <CAGXu5jLFwQuUyZuRuK60YBGYbbEkt+C3dKxCyDe65Ad5co2oLw@mail.gmail.com> (raw)
In-Reply-To: <20170130094940.13546-6-mhocko@kernel.org>

On Mon, Jan 30, 2017 at 1:49 AM, Michal Hocko <mhocko@kernel.org> wrote:
> From: Michal Hocko <mhocko@suse.com>
>
> There are many code paths opencoding kvmalloc. Let's use the helper
> instead. The main difference to kvmalloc is that those users are usually
> not considering all the aspects of the memory allocator. E.g. allocation
> requests <= 32kB (with 4kB pages) are basically never failing and invoke
> OOM killer to satisfy the allocation. This sounds too disruptive for
> something that has a reasonable fallback - the vmalloc. On the other
> hand those requests might fallback to vmalloc even when the memory
> allocator would succeed after several more reclaim/compaction attempts
> previously. There is no guarantee something like that happens though.
>
> This patch converts many of those places to kv[mz]alloc* helpers because
> they are more conservative.
>
> Changes since v1
> - add kvmalloc_array - this might silently fix some overflow issues
>   because most users simply didn't check the overflow for the vmalloc
>   fallback.

Awesome, thanks for adding that API. :)

Acked-by: Kees Cook <keescook@chromium.org>

-Kees

-- 
Kees Cook
Nexus Security

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  parent reply	other threads:[~2017-01-30 19:24 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-30  9:49 [PATCH 0/6 v3] kvmalloc Michal Hocko
2017-01-30  9:49 ` [PATCH 1/9] mm: introduce kv[mz]alloc helpers Michal Hocko
2017-01-30  9:49 ` [PATCH 2/9] mm: support __GFP_REPEAT in kvmalloc_node for >32kB Michal Hocko
2017-01-30  9:49 ` [PATCH 3/9] rhashtable: simplify a strange allocation pattern Michal Hocko
2017-01-30 14:04   ` Vlastimil Babka
2017-01-30  9:49 ` [PATCH 4/9] ila: " Michal Hocko
2017-01-30 15:21   ` Vlastimil Babka
2017-01-30  9:49 ` [PATCH 5/9] treewide: use kv[mz]alloc* rather than opencoded variants Michal Hocko
2017-01-30 10:21   ` Leon Romanovsky
2017-01-30 16:14   ` Vlastimil Babka
2017-01-30 19:24   ` Kees Cook [this message]
2017-01-30  9:49 ` [PATCH 6/9] net: use kvmalloc with __GFP_REPEAT rather than open coded variant Michal Hocko
2017-01-30 16:36   ` Vlastimil Babka
2017-01-30  9:49 ` [PATCH 7/9] md: use kvmalloc rather than opencoded variant Michal Hocko
2017-01-30 16:42   ` Vlastimil Babka
2017-02-01 17:29   ` Mikulas Patocka
2017-02-01 17:58     ` Michal Hocko
2017-01-30  9:49 ` [PATCH 8/9] bcache: use kvmalloc Michal Hocko
2017-01-30 16:47   ` Vlastimil Babka
2017-01-30 17:25     ` Michal Hocko
2017-01-30  9:49 ` [PATCH 9/9] net, bpf: use kvzalloc helper Michal Hocko
2017-01-30 17:20   ` Michal Hocko
2017-02-05 10:23 ` [PATCH 0/6 v3] kvmalloc Michal Hocko

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