From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754016Ab2G3MDr (ORCPT ); Mon, 30 Jul 2012 08:03:47 -0400 Received: from mail-gh0-f174.google.com ([209.85.160.174]:57187 "EHLO mail-gh0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753630Ab2G3MBp (ORCPT ); Mon, 30 Jul 2012 08:01:45 -0400 From: Anton Vorontsov To: Russell King , Jason Wessel , Greg Kroah-Hartman , Alan Cox Cc: =?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= , Colin Cross , John Stultz , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linaro-kernel@lists.linaro.org, patches@linaro.org, kernel-team@android.com, kgdb-bugreport@lists.sourceforge.net Subject: [PATCH 03/11] kdb: Implement disable_nmi command Date: Mon, 30 Jul 2012 04:58:12 -0700 Message-Id: <1343649500-18491-3-git-send-email-anton.vorontsov@linaro.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <20120730115719.GA5742@lizard> References: <20120730115719.GA5742@lizard> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This command disables NMI-entry. If NMI source was previously shared with a serial console ("debug port"), this effectively releases the port from KDB exclusive use, and makes the console available for normal use. Of course, NMI can be reenabled, enable_nmi modparam is used for that: echo 1 > /sys/module/kdb/parameters/enable_nmi Signed-off-by: Anton Vorontsov --- kernel/debug/kdb/kdb_main.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index 3ee92a1..1e9f20e 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -2131,6 +2131,24 @@ static int kdb_dmesg(int argc, const char **argv) return 0; } #endif /* CONFIG_PRINTK */ + +static int kdb_disable_nmi(int argc, const char *argv[]) +{ + kgdb_arch_enable_nmi(0); + return 0; +} + +static int kdb_param_enable_nmi(const char *val, const struct kernel_param *kp) +{ + kgdb_arch_enable_nmi(1); + return 0; +} + +static const struct kernel_param_ops kdb_param_ops_enable_nmi = { + .set = kdb_param_enable_nmi, +}; +module_param_cb(enable_nmi, &kdb_param_ops_enable_nmi, NULL, 0600); + /* * kdb_cpu - This function implements the 'cpu' command. * cpu [] @@ -2873,6 +2891,8 @@ static void __init kdb_inittab(void) kdb_register_flags("dmesg", kdb_dmesg, "[lines]", "Display syslog buffer", 0, KDB_SAFE); #endif + kdb_register_flags("disable_nmi", kdb_disable_nmi, "", + "Disable NMI entry to KDB", 0, KDB_SAFE); kdb_register_flags("defcmd", kdb_defcmd, "name \"usage\" \"help\"", "Define a set of commands, down to endefcmd", 0, KDB_SAFE); kdb_register_flags("kill", kdb_kill, "<-signal> ", -- 1.7.10.4