From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: Re: [PATCH 7/7] bug: Move WARN_ON() "cut here" into exception handler Date: Tue, 20 Aug 2019 21:14:29 -0400 Message-ID: <20190820211429.7030b6f6@oasis.local.home> References: <20190819234111.9019-1-keescook@chromium.org> <20190819234111.9019-8-keescook@chromium.org> <20190820100638.GK2332@hirez.programming.kicks-ass.net> <06ba33fd-27cc-3816-1cdf-70616b1782dd@c-s.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <06ba33fd-27cc-3816-1cdf-70616b1782dd@c-s.fr> Sender: linux-kernel-owner@vger.kernel.org To: Christophe Leroy Cc: Peter Zijlstra , Kees Cook , Andrew Morton , Drew Davenport , Arnd Bergmann , Feng Tang , Petr Mladek , Mauro Carvalho Chehab , Borislav Petkov , YueHaibing , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-arch.vger.kernel.org On Tue, 20 Aug 2019 12:58:49 +0200 Christophe Leroy wrote: > >> index 1077366f496b..6c22e8a6f9de 100644 > >> --- a/lib/bug.c > >> +++ b/lib/bug.c > >> @@ -181,6 +181,15 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs) > >> } > >> } > >> > >> + /* > >> + * BUG() and WARN_ON() families don't print a custom debug message > >> + * before triggering the exception handler, so we must add the > >> + * "cut here" line now. WARN() issues its own "cut here" before the > >> + * extra debugging message it writes before triggering the handler. > >> + */ > >> + if ((bug->flags & BUGFLAG_PRINTK) == 0) > >> + printk(KERN_DEFAULT CUT_HERE); > > > > I'm not loving that BUGFLAG_PRINTK name, BUGFLAG_CUT_HERE makes more > > sense to me. > > > > Actually it would be BUGFLAG_NO_CUT_HERE then, otherwise all arches not > using the generic macros will have to add the flag to get the "cut here" > line. > Perhaps they all should be audited to see if they don't have the same problem? -- Steve From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:39976 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726202AbfHUBOg (ORCPT ); Tue, 20 Aug 2019 21:14:36 -0400 Date: Tue, 20 Aug 2019 21:14:29 -0400 From: Steven Rostedt Subject: Re: [PATCH 7/7] bug: Move WARN_ON() "cut here" into exception handler Message-ID: <20190820211429.7030b6f6@oasis.local.home> In-Reply-To: <06ba33fd-27cc-3816-1cdf-70616b1782dd@c-s.fr> References: <20190819234111.9019-1-keescook@chromium.org> <20190819234111.9019-8-keescook@chromium.org> <20190820100638.GK2332@hirez.programming.kicks-ass.net> <06ba33fd-27cc-3816-1cdf-70616b1782dd@c-s.fr> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Christophe Leroy Cc: Peter Zijlstra , Kees Cook , Andrew Morton , Drew Davenport , Arnd Bergmann , Feng Tang , Petr Mladek , Mauro Carvalho Chehab , Borislav Petkov , YueHaibing , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Message-ID: <20190821011429.3Yj4jfGE5dXwLQn3KZmm5jYQBCBqZ04QzP3aafwUtNQ@z> On Tue, 20 Aug 2019 12:58:49 +0200 Christophe Leroy wrote: > >> index 1077366f496b..6c22e8a6f9de 100644 > >> --- a/lib/bug.c > >> +++ b/lib/bug.c > >> @@ -181,6 +181,15 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs) > >> } > >> } > >> > >> + /* > >> + * BUG() and WARN_ON() families don't print a custom debug message > >> + * before triggering the exception handler, so we must add the > >> + * "cut here" line now. WARN() issues its own "cut here" before the > >> + * extra debugging message it writes before triggering the handler. > >> + */ > >> + if ((bug->flags & BUGFLAG_PRINTK) == 0) > >> + printk(KERN_DEFAULT CUT_HERE); > > > > I'm not loving that BUGFLAG_PRINTK name, BUGFLAG_CUT_HERE makes more > > sense to me. > > > > Actually it would be BUGFLAG_NO_CUT_HERE then, otherwise all arches not > using the generic macros will have to add the flag to get the "cut here" > line. > Perhaps they all should be audited to see if they don't have the same problem? -- Steve