Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752203AbZIXLtX (ORCPT ); Thu, 24 Sep 2009 07:49:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751832AbZIXLtW (ORCPT ); Thu, 24 Sep 2009 07:49:22 -0400 Received: from hera.kernel.org ([140.211.167.34]:48508 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751676AbZIXLtV (ORCPT ); Thu, 24 Sep 2009 07:49:21 -0400 Date: Thu, 24 Sep 2009 11:48:52 GMT From: tip-bot for Jason Wessel Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, torvalds@linux-foundation.org, jason.wessel@windriver.com, lenb@kernel.org, akpm@linux-foundation.org, gregkh@suse.de, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, lenb@kernel.org, akpm@linux-foundation.org, jason.wessel@windriver.com, torvalds@linux-foundation.org, gregkh@suse.de, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <4ABAAB89.1080407@windriver.com> References: <4ABAAB89.1080407@windriver.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86: early_printk: Protect against using the same device twice Message-ID: Git-Commit-ID: 429a6e5e2c1fbe5d805aad123efbdb5f0c14769f X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Thu, 24 Sep 2009 11:48:53 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2813 Lines: 64 Commit-ID: 429a6e5e2c1fbe5d805aad123efbdb5f0c14769f Gitweb: http://git.kernel.org/tip/429a6e5e2c1fbe5d805aad123efbdb5f0c14769f Author: Jason Wessel AuthorDate: Wed, 23 Sep 2009 18:13:13 -0500 Committer: Ingo Molnar CommitDate: Thu, 24 Sep 2009 13:01:13 +0200 x86: early_printk: Protect against using the same device twice If you use the kernel argument: earlyprintk=serial,ttyS0,115200 This will cause a recursive hang printing the same line again and again: BIOS-e820: 000000003fff3000 - 0000000040000000 (ACPI data) BIOS-e820: 00000000e0000000 - 00000000f0000000 (reserved) BIOS-e820: 00000000fec00000 - 0000000100000000 (reserved) bootconsole [earlyser0] enabled Linux version 2.6.31-07863-gb64ada6 (mingo@sirius) (gcc version 4.3.2 20081105 (Red Hat 4.3.2-7) (GCC) ) #16789 SMP Wed Sep 23 21:09:43 CEST 2009 Linux version 2.6.31-07863-gb64ada6 (mingo@sirius) (gcc version 4.3.2 20081105 (Red Hat 4.3.2-7) (GCC) ) #16789 SMP Wed Sep 23 21:09:43 CEST 2009 Linux version 2.6.31-07863-gb64ada6 (mingo@sirius) (gcc version 4.3.2 20081105 (Red Hat 4.3.2-7) (GCC) ) #16789 SMP Wed Sep 23 21:09:43 CEST 2009 Linux version 2.6.31-07863-gb64ada6 (mingo@sirius) (gcc version 4.3.2 20081105 (Red Hat 4.3.2-7) (GCC) ) #16789 SMP Wed Sep 23 21:09:43 CEST 2009 Linux version 2.6.31-07863-gb64ada6 (mingo@sirius) (gcc version 4.3.2 20081105 (Red Hat 4.3.2-7) (GCC) ) #16789 SMP Wed Sep 23 21:09:43 CEST 2009 Instead warn the end user that they specified the device a second time, and ignore that second console. Reported-by: Ingo Molnar Signed-off-by: Jason Wessel Cc: Len Brown Cc: Greg KH Cc: Andrew Morton Cc: Linus Torvalds LKML-Reference: <4ABAAB89.1080407@windriver.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/early_printk.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c index 2acfd3f..41fd965 100644 --- a/arch/x86/kernel/early_printk.c +++ b/arch/x86/kernel/early_printk.c @@ -178,6 +178,11 @@ asmlinkage void early_printk(const char *fmt, ...) static inline void early_console_register(struct console *con, int keep_early) { + if (early_console->index != -1) { + printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n", + con->name); + return; + } early_console = con; if (keep_early) early_console->flags &= ~CON_BOOT; -- 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/