From: Topi Miettinen <toiwoton@gmail.com>
To: David Hildenbrand <david@redhat.com>,
akpm@linux-foundation.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: optionally disable brk()
Date: Sat, 3 Oct 2020 00:44:09 +0300 [thread overview]
Message-ID: <2a0f5ade-d770-c36e-50bc-ff0c8e9dacbf@gmail.com> (raw)
In-Reply-To: <653873ef-2a57-37e0-1ac3-fba763652b35@redhat.com>
On 2.10.2020 20.52, David Hildenbrand wrote:
> On 02.10.20 19:19, Topi Miettinen wrote:
>> The brk() system call allows to change data segment size (heap). This
>> is mainly used by glibc for memory allocation, but it can use mmap()
>> and that results in more randomized memory mappings since the heap is
>> always located at fixed offset to program while mmap()ed memory is
>> randomized.
>
> Want to take more Unix out of Linux?
>
> Honestly, why care about disabling? User space can happily use mmap() if
> it prefers.
brk() interface doesn't seem to be used much and glibc is happy to
switch to mmap() if brk() fails, so why not allow disabling it
optionally? If you don't care to disable, don't do it and this is even
the default.
-Topi
next prev parent reply other threads:[~2020-10-02 21:44 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-02 17:19 [PATCH] mm: optionally disable brk() Topi Miettinen
2020-10-02 17:52 ` David Hildenbrand
2020-10-02 21:19 ` David Laight
2020-10-02 21:44 ` Topi Miettinen [this message]
2020-10-05 6:12 ` Michal Hocko
2020-10-05 8:11 ` Topi Miettinen
2020-10-05 8:22 ` Michal Hocko
2020-10-05 9:03 ` Topi Miettinen
2020-10-05 14:12 ` Jonathan Corbet
2020-10-05 16:14 ` Topi Miettinen
2020-10-05 9:13 ` David Hildenbrand
2020-10-05 9:20 ` Michal Hocko
2020-10-05 9:47 ` Topi Miettinen
2020-10-05 9:55 ` David Hildenbrand
2020-10-05 11:21 ` David Laight
2020-10-05 12:18 ` David Hildenbrand
2020-10-05 12:25 ` David Laight
2020-10-07 9:43 ` Topi Miettinen
2020-11-01 11:41 ` Topi Miettinen
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