From: Paul Mundt <lethal@linux-sh.org>
To: Mike Frysinger <vapier@gentoo.org>
Cc: uclinux-dev@uclinux.org, David Howells <dhowells@redhat.com>,
David McCullough <davidm@snapgear.com>,
Greg Ungerer <gerg@uclinux.org>,
linux-kernel@vger.kernel.org,
uclinux-dist-devel@blackfin.uclinux.org,
Jie Zhang <jie.zhang@analog.com>, Robin Getz <rgetz@analog.com>
Subject: Re: [PATCH v2] NOMMU: fix malloc performance by adding uninitialized flag
Date: Tue, 13 Oct 2009 22:03:36 +0900 [thread overview]
Message-ID: <20091013130336.GA1245@linux-sh.org> (raw)
In-Reply-To: <1255432821-1104-1-git-send-email-vapier@gentoo.org>
On Tue, Oct 13, 2009 at 07:20:21AM -0400, Mike Frysinger wrote:
> From: Jie Zhang <jie.zhang@analog.com>
>
> The NOMMU code currently clears all anonymous mmapped memory. While this
> is what we want in the default case, all memory allocation from userspace
> under NOMMU has to go through this interface, including malloc() which is
> allowed to return uninitialized memory. This can easily be a significant
> performance penalty. So for constrained embedded systems were security is
> irrelevant, allow people to avoid clearing memory unnecessarily.
>
> This also alters the ELF-FDPIC binfmt such that it obtains uninitialised
> memory for the brk and stack region.
>
> Signed-off-by: Jie Zhang <jie.zhang@analog.com>
> Signed-off-by: Robin Getz <rgetz@analog.com>
> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
> Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
next prev parent reply other threads:[~2009-10-13 13:05 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-30 3:42 [PATCH] nommu arch dont zero the anonymous mapping by adding UNINITIALIZE flag Wu, Bryan
2007-03-30 3:53 ` Mike Frysinger
2007-03-30 9:39 ` David Howells
2007-03-30 10:34 ` Aubrey Li
2007-03-30 11:24 ` David Howells
2007-03-30 13:44 ` Aubrey Li
2007-03-30 14:56 ` Alan Cox
2007-03-30 14:38 ` Aubrey Li
2007-03-30 15:11 ` David Howells
2007-03-30 15:46 ` Aubrey Li
2009-10-13 7:44 ` [PATCH] NOMMU: fix malloc performance by adding uninitialized flag Mike Frysinger
2009-10-13 10:10 ` David Howells
2009-10-13 11:20 ` [PATCH v2] " Mike Frysinger
2009-10-13 13:03 ` Paul Mundt [this message]
2009-10-13 16:03 ` David Howells
2009-10-13 21:31 ` [PATCH v3] " Mike Frysinger
2009-10-13 23:04 ` David McCullough
2009-10-14 0:25 ` Greg Ungerer
2009-10-13 15:20 ` [uClinux-dev] [PATCH] NOMMU: fix malloc performance by addinguninitialized flag Robin Getz
2007-03-30 18:13 ` [PATCH] nommu arch dont zero the anonymous mapping by adding UNINITIALIZE flag Alan Cox
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