Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753670AbaBLUNV (ORCPT ); Wed, 12 Feb 2014 15:13:21 -0500 Received: from mail-vc0-f171.google.com ([209.85.220.171]:58146 "EHLO mail-vc0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753084AbaBLUNU (ORCPT ); Wed, 12 Feb 2014 15:13:20 -0500 MIME-Version: 1.0 In-Reply-To: <20140212113928.GO18016@ZenIV.linux.org.uk> References: <20140211172707.GA1749@redhat.com> <20140211210841.GM13647@dastard> <52FA9ADA.9040803@sandeen.net> <20140212004403.GA17129@redhat.com> <20140212010941.GM18016@ZenIV.linux.org.uk> <20140212040358.GA25327@redhat.com> <20140212042215.GN18016@ZenIV.linux.org.uk> <20140212054043.GB13997@dastard> <20140212113928.GO18016@ZenIV.linux.org.uk> Date: Wed, 12 Feb 2014 12:13:19 -0800 X-Google-Sender-Auth: pxORrkSP4cPaPAaczNRJC15i-Ok Message-ID: Subject: Re: 3.14-rc2 XFS backtrace because irqs_disabled. From: Linus Torvalds To: Al Viro Cc: Dave Chinner , Dave Jones , Eric Sandeen , Linux Kernel , xfs@oss.sgi.com Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 12, 2014 at 3:39 AM, Al Viro wrote: > On Tue, Feb 11, 2014 at 10:28:12PM -0800, Linus Torvalds wrote: > >> It looks like just "do_signal()" has a stack frame that is about 230 >> bytes even under normal circumstancs (largely due to "struct ksignal" >> - which in turn is largely due to the insane 128-byte padding in >> siginfo_t). Add a few other frames in there, and I guess that if it >> was close before, the coredump path just makes it go off. > > We could, in principle, put it into task_struct and make get_signal() > return its address - do_signal() is called only in the code that does > assorted returns to userland... We have better uses for random buffers in "struct task_struct", I'd hate to put a siginfo_t there. The thing is, siginfo_t has that idiotic 128-byte area, but it's all "for future expansion". I think it's some damn glibc disease - we've seen these kinds of insane paddings before. The actual *useful* part of siginfo_t is on the order of 32 bytes. If that. Sad. Linus -- 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/