Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763955AbYBTO0c (ORCPT ); Wed, 20 Feb 2008 09:26:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756891AbYBTO0Y (ORCPT ); Wed, 20 Feb 2008 09:26:24 -0500 Received: from poesci.dolphinics.no ([81.175.23.36]:33465 "EHLO poesci.dolphinics.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755510AbYBTO0X (ORCPT ); Wed, 20 Feb 2008 09:26:23 -0500 X-Greylist: delayed 1772 seconds by postgrey-1.27 at vger.kernel.org; Wed, 20 Feb 2008 09:26:23 EST From: Arne Georg Gleditsch To: linux-kernel@vger.kernel.org Cc: John Stultz Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Andi Kleen Cc: Roman Zippel Subject: arch/x86/kernel/vsyscall_64.c: overeager NOP of syscalls Date: Wed, 20 Feb 2008 14:57:34 +0100 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 843 Lines: 21 Hi, I'm looking at 2.6.25-rc2. vsyscall_sysctl_change contains code to NOP out the actual system call instructions of the vsyscall page when vsyscall64 is enabled. This seems to interact badly with the fallback code in do_vgettimeofday which tries to call gettimeofday if the configured clock source does not support vread. (In effect, gettimeofday() becomes a nop and time() always returns 0. Not very useful.) Is there a good reason to keep this? Aren't the instructions in question avoided (or invoked) according to the vsyscall64 flag by the surrounding logic anyway? -- Arne. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/