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[209.132.180.67]) by mx.google.com with ESMTP id fh2si5739807pdb.215.2014.11.26.01.16.48 for ; Wed, 26 Nov 2014 01:16:48 -0800 (PST) Received-SPF: none (google.com: linux-kernel-owner@vger.kernel.org does not designate permitted sender hosts) client-ip=209.132.180.67; Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752387AbaKZJQp (ORCPT + 26 others); Wed, 26 Nov 2014 04:16:45 -0500 Received: from mail-pd0-f172.google.com ([209.85.192.172]:40246 "EHLO mail-pd0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750914AbaKZJQm (ORCPT ); Wed, 26 Nov 2014 04:16:42 -0500 Received: by mail-pd0-f172.google.com with SMTP id y13so2478723pdi.3 for ; Wed, 26 Nov 2014 01:16:41 -0800 (PST) X-Received: by 10.70.126.194 with SMTP id na2mr52248574pdb.39.1416993401819; Wed, 26 Nov 2014 01:16:41 -0800 (PST) Received: from c-krapar-linux.qualcomm.com ([202.46.23.54]) by mx.google.com with ESMTPSA id jp15sm3716111pbb.17.2014.11.26.01.16.38 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Wed, 26 Nov 2014 01:16:41 -0800 (PST) From: Kiran Raparthy To: linux-kernel@vger.kernel.org Cc: Colin Cross , Jason Wessel , kgdb-bugreport@lists.sourceforge.net, Android Kernel Team , John Stultz , Sumit Semwal , Kiran Raparthy Subject: [RFC v3] debug: prevent entering debug mode on errors Date: Wed, 26 Nov 2014 14:44:26 +0530 Message-Id: <1416993266-16514-1-git-send-email-kiran.kumar@linaro.org> X-Mailer: git-send-email 1.8.2.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: list List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: kiran.kumar@linaro.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.215.44 as permitted sender) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , From: Colin Cross debug: prevent entering debug mode on errors On non-developer devices kgdb prevents CONFIG_PANIC_TIMEOUT from rebooting the device after a panic. In case of panics and exceptions, to honor CONFIG_PANIC_TIMEOUT, prevent entering debug mode to avoid getting stuck waiting for the user to interact with debugger. Cc: Jason Wessel Cc: kgdb-bugreport@lists.sourceforge.net Cc: linux-kernel@vger.kernel.org Cc: Android Kernel Team Cc: John Stultz Cc: Sumit Semwal Signed-off-by: Colin Cross [Kiran: Added context to commit message. panic_timeout is used instead of break_on_panic and break_on_exception to honor CONFIG_PANIC_TIMEOUT] Signed-off-by: Kiran Raparthy Reviewed-by: Daniel Thompson --- kernel/debug/debug_core.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 1adf62b..0012a1f 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -689,6 +689,14 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs) if (arch_kgdb_ops.enable_nmi) arch_kgdb_ops.enable_nmi(0); + /* + * Avoid entering the debugger if we were triggered due to an oops + * but panic_timeout indicates the system should automatically + * reboot on panic. We don't want to get stuck waiting for input + * on such systems, especially if its "just" an oops. + */ + if (signo != SIGTRAP && panic_timeout) + return 1; memset(ks, 0, sizeof(struct kgdb_state)); ks->cpu = raw_smp_processor_id(); @@ -821,6 +829,15 @@ static int kgdb_panic_event(struct notifier_block *self, unsigned long val, void *data) { + /* + * Avoid entering the debugger if we were triggered due to a panic + * We don't want to get stuck waiting for input from user in such case. + * panic_timeout indicates the system should automatically + * reboot on panic. + */ + if (panic_timeout) + return NOTIFY_DONE; + if (dbg_kdb_mode) kdb_printf("PANIC: %s\n", (char *)data); kgdb_breakpoint();