From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754486Ab0C2PhL (ORCPT ); Mon, 29 Mar 2010 11:37:11 -0400 Received: from mgw1.diku.dk ([130.225.96.91]:48629 "EHLO mgw1.diku.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754456Ab0C2PhI (ORCPT ); Mon, 29 Mar 2010 11:37:08 -0400 Date: Mon, 29 Mar 2010 17:37:02 +0200 (CEST) From: Julia Lawall To: Steven Rostedt , Frederic Weisbecker , Ingo Molnar , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH 12/12] kernel/trace: Add missing unlock Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Julia Lawall In some error handling cases the lock is not unlocked. The return is converted to a goto, to share the unlock at the end of the function. A simplified version of the semantic patch that finds this problem is as follows: (http://coccinelle.lip6.fr/) // @r exists@ expression E1; identifier f; @@ f (...) { <+... * spin_lock_irq (E1,...); ... when != E1 * return ...; ...+> } // Signed-off-by: Julia Lawall --- kernel/trace/ring_buffer.c | 8 +++++--- 1 files changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 05a9f83..cd2e1d8 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1201,18 +1201,19 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages) for (i = 0; i < nr_pages; i++) { if (RB_WARN_ON(cpu_buffer, list_empty(cpu_buffer->pages))) - return; + goto out; p = cpu_buffer->pages->next; bpage = list_entry(p, struct buffer_page, list); list_del_init(&bpage->list); free_buffer_page(bpage); } if (RB_WARN_ON(cpu_buffer, list_empty(cpu_buffer->pages))) - return; + goto out; rb_reset_cpu(cpu_buffer); rb_check_pages(cpu_buffer); +out: spin_unlock_irq(&cpu_buffer->reader_lock); } @@ -1229,7 +1230,7 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer, for (i = 0; i < nr_pages; i++) { if (RB_WARN_ON(cpu_buffer, list_empty(pages))) - return; + goto out; p = pages->next; bpage = list_entry(p, struct buffer_page, list); list_del_init(&bpage->list); @@ -1238,6 +1239,7 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer, rb_reset_cpu(cpu_buffer); rb_check_pages(cpu_buffer); +out: spin_unlock_irq(&cpu_buffer->reader_lock); }