linux-kernel - Re: [PATCH v2 2/2] x86_64,signal: Remove 'fs' and 'gs' from sigcontext

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: <20150311123233.GE16419@pd.tnic>
Date:	Wed, 11 Mar 2015 13:32:33 +0100
From:	Borislav Petkov <bp@...en8.de>
To:	Andy Lutomirski <luto@...capital.net>
Cc:	Andi Kleen <andi@...stfloor.org>, "H. Peter Anvin" <hpa@...or.com>,
	X86 ML <x86@...nel.org>, Al Viro <viro@...iv.linux.org.uk>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Ingo Molnar <mingo@...nel.org>
Subject: Re: [PATCH v2 2/2] x86_64,signal: Remove 'fs' and 'gs' from
 sigcontext

On Wed, Mar 11, 2015 at 05:22:48AM -0700, Andy Lutomirski wrote:
> Wait... It looks like it really was saving them.  Of course, this is

Bah, of course. Blind me.

> IOW, in 2.5.63 and earlier, we tried to save and restore TLS state
> across signals, but we did it wrong and would corrupt it for any
> program that used arch_prctl.  At that time, programs could switch
> userspace threads using signals and their TLS pointers would switch.
> In 2.5.64 and later, we broke set_thread_area users, fixed arch_prctl

That is probably non-issue as 2.5 was the devel branch anyway in the old
days. I'm not sure what the statement on breaking ABI was though then...

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--
--
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/