linux-kernel - Re: [PATCH] x86, syscall: Fix _TIF_NOHZ handling in syscall_trace_enter

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]

Date:	Wed, 19 Nov 2014 23:13:53 +0100 (CET)
From:	Thomas Gleixner <tglx@...utronix.de>
To:	Andy Lutomirski <luto@...capital.net>
cc:	Dave Jones <davej@...hat.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Don Zickus <dzickus@...hat.com>,
	Linux Kernel <linux-kernel@...r.kernel.org>, x86@...nel.org,
	Peter Zijlstra <peterz@...radead.org>
Subject: Re: [PATCH] x86, syscall: Fix _TIF_NOHZ handling in
 syscall_trace_enter_phase1

On Wed, 19 Nov 2014, Andy Lutomirski wrote:

> TIF_NOHZ is 19 (i.e. _TIF_SYSCALL_TRACE | _TIF_NOTIFY_RESUME |
> _TIF_SINGLESTEP), not (1<<19).
> 
> This code is involved in Dave's trinity lockup, but I don't see why
> it would cause any of the problems he's seeing, except inadvertently
> by causing a different path through entry_64.S's syscall handling.

Right, while it is wrong it does not explain the wreckage on 3.17,
which does not have that code.

Thanks,

	tglx
--
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/