Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932429AbaBGLvl (ORCPT ); Fri, 7 Feb 2014 06:51:41 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:42228 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755136AbaBGLvi (ORCPT ); Fri, 7 Feb 2014 06:51:38 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Steven Rostedt , Luis Henriques Subject: [PATCH 3.11 171/233] tracing: Check if tracing is enabled in trace_puts() Date: Fri, 7 Feb 2014 11:46:30 +0000 Message-Id: <1391773652-25214-172-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1391773652-25214-1-git-send-email-luis.henriques@canonical.com> References: <1391773652-25214-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.11.10.4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: "Steven Rostedt (Red Hat)" commit 3132e107d608f8753240d82d61303c500fd515b4 upstream. If trace_puts() is used very early in boot up, it can crash the machine if it is called before the ring buffer is allocated. If a trace_printk() is used with no arguments, then it will be converted into a trace_puts() and suffer the same fate. Fixes: 09ae72348ecc "tracing: Add trace_puts() for even faster trace_printk() tracing" Signed-off-by: Steven Rostedt Signed-off-by: Luis Henriques --- kernel/trace/trace.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 878785b..f788ecf 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -435,6 +435,9 @@ int __trace_puts(unsigned long ip, const char *str, int size) unsigned long irq_flags; int alloc; + if (unlikely(tracing_selftest_running || tracing_disabled)) + return 0; + alloc = sizeof(*entry) + size + 2; /* possible \n added */ local_save_flags(irq_flags); @@ -475,6 +478,9 @@ int __trace_bputs(unsigned long ip, const char *str) unsigned long irq_flags; int size = sizeof(struct bputs_entry); + if (unlikely(tracing_selftest_running || tracing_disabled)) + return 0; + local_save_flags(irq_flags); buffer = global_trace.trace_buffer.buffer; event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size, -- 1.8.3.2 -- 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/