From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756416AbZLUBUf (ORCPT ); Sun, 20 Dec 2009 20:20:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756367AbZLUBU3 (ORCPT ); Sun, 20 Dec 2009 20:20:29 -0500 Received: from one.firstfloor.org ([213.235.205.2]:37712 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756354AbZLUBU2 (ORCPT ); Sun, 20 Dec 2009 20:20:28 -0500 From: Andi Kleen References: <20091221220.243954235@firstfloor.org> In-Reply-To: <20091221220.243954235@firstfloor.org> To: linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com, ebiederm@xmission.com Subject: [PATCH] [4/11] SYSCTL: Use RCU strings for core_pattern sysctl Message-Id: <20091221012025.A2FA2B158A@basil.firstfloor.org> Date: Mon, 21 Dec 2009 02:20:25 +0100 (CET) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As a bonus this removes one use of the BKL. Signed-off-by: Andi Kleen --- fs/exec.c | 9 ++++----- kernel/sysctl.c | 6 +++--- 2 files changed, 7 insertions(+), 8 deletions(-) Index: linux-2.6.33-rc1-ak/fs/exec.c =================================================================== --- linux-2.6.33-rc1-ak.orig/fs/exec.c +++ linux-2.6.33-rc1-ak/fs/exec.c @@ -62,7 +62,7 @@ #include "internal.h" int core_uses_pid; -char core_pattern[CORENAME_MAX_SIZE] = "core"; +char *core_pattern = "core"; unsigned int core_pipe_limit; int suid_dumpable = 0; @@ -1825,12 +1825,11 @@ void do_coredump(long signr, int exit_co clear_thread_flag(TIF_SIGPENDING); /* - * lock_kernel() because format_corename() is controlled by sysctl, which - * uses lock_kernel() + * Protect corename by RCU vs proc_rcu_string() */ - lock_kernel(); + rcu_read_lock(); ispipe = format_corename(corename, signr); - unlock_kernel(); + rcu_read_unlock(); if ((!ispipe) && (cprm.limit < binfmt->min_coredump)) goto fail_unlock; Index: linux-2.6.33-rc1-ak/kernel/sysctl.c =================================================================== --- linux-2.6.33-rc1-ak.orig/kernel/sysctl.c +++ linux-2.6.33-rc1-ak/kernel/sysctl.c @@ -75,7 +75,7 @@ extern int sysctl_oom_dump_tasks; extern int max_threads; extern int core_uses_pid; extern int suid_dumpable; -extern char core_pattern[]; +extern char *core_pattern; extern unsigned int core_pipe_limit; extern int pid_max; extern int min_free_kbytes; @@ -399,10 +399,10 @@ static struct ctl_table kern_table[] = { }, { .procname = "core_pattern", - .data = core_pattern, + .data = &core_pattern, .maxlen = CORENAME_MAX_SIZE, .mode = 0644, - .proc_handler = proc_dostring, + .proc_handler = proc_rcu_string, }, { .procname = "core_pipe_limit",