linux-kernel - Re: [PATCH 15/18] x86 vDSO: consolidate vdso32

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1195604010.6352.237.camel@bodhitayantram.eng.vmware.com>
Date:	Tue, 20 Nov 2007 16:13:30 -0800
From:	Zachary Amsden <zach@...are.com>
To:	Roland McGrath <roland@...hat.com>, Ingo Molnar <mingo@...e.hu>,
	Andi Kleen <ak@...e.de>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 15/18] x86 vDSO: consolidate vdso32

On Mon, 2007-11-19 at 14:06 -0800, Roland McGrath wrote:
> This makes x86_64's ia32 emulation support share the sources used in the
> 32-bit kernel for the 32-bit vDSO and much of its setup code.
> 
> The 32-bit vDSO mapping now behaves the same on x86_64 as on native 32-bit.
> The abi.syscall32 sysctl on x86_64 now takes the same values that
> vm.vdso_enabled takes on the 32-bit kernel.  That is, 1 means a randomized
> vDSO location, 2 means the fixed old address.  The CONFIG_COMPAT_VDSO
> option is now available to make this the default setting, the same meaning
> it has for the 32-bit kernel.  (This does not affect the 64-bit vDSO.)

I think you should drop CONFIG_COMPAT_VDSO support for 32-bit VDSO on
64-bit kernel.  This was only to hack around a broken version of glibc
that shipped with SUSE PRO 9.0, which had broken assertions based on
misinterpretation of ELF fields.  64-bit machines will never see this
glibc and the hack can die.

Perhaps it is finally time to remove the hack from 32-bit as well, and
eliminate COMPAT_VDSO entirely?  Or does it really have to live forever.

Zach

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/