Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760697AbXJLJfk (ORCPT ); Fri, 12 Oct 2007 05:35:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759519AbXJLJfa (ORCPT ); Fri, 12 Oct 2007 05:35:30 -0400 Received: from sullivan.realtime.net ([205.238.132.226]:4462 "EHLO sullivan.realtime.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758024AbXJLJf3 (ORCPT ); Fri, 12 Oct 2007 05:35:29 -0400 Date: Fri, 12 Oct 2007 04:35:19 -0500 (CDT) From: Milton Miller Subject: [PATCH] sched domain sysctl: free and rebuild when changing domains In-Reply-To: Message-Id: To: Ingo Molnar Cc: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2826 Lines: 99 Unregister and free the sysctl table before destroying domains, then rebuild and register after creating the new domains. This prevents the sysctl table from pointing to freed memory for root to write. Signed-off-by: Milton Miller Index: kernel/kernel/sched.c =================================================================== --- kernel.orig/kernel/sched.c 2007-10-12 03:55:19.000000000 -0500 +++ kernel/kernel/sched.c 2007-10-12 03:58:35.000000000 -0500 @@ -5291,6 +5291,18 @@ static struct ctl_table *sd_alloc_ctl_en return entry; } +static void sd_free_ctl_entry(struct ctl_table **tablep) +{ + struct ctl_table *entry = *tablep; + + for (entry = *tablep; entry->procname; entry++) + if (entry->child) + sd_free_ctl_entry(&entry->child); + + kfree(*tablep); + *tablep = NULL; +} + static void set_table_entry(struct ctl_table *entry, const char *procname, void *data, int maxlen, @@ -5359,7 +5371,7 @@ static ctl_table *sd_alloc_ctl_cpu_table } static struct ctl_table_header *sd_sysctl_header; -static void init_sched_domain_sysctl(void) +static void register_sched_domain_sysctl(void) { int i, cpu_num = num_online_cpus(); struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); @@ -5376,8 +5388,18 @@ static void init_sched_domain_sysctl(voi } sd_sysctl_header = register_sysctl_table(sd_ctl_root); } + +static void unregister_sched_domain_sysctl(void) +{ + unregister_sysctl_table(sd_sysctl_header); + sd_sysctl_header = NULL; + sd_free_ctl_entry(&sd_ctl_dir[0].child); +} #else -static void init_sched_domain_sysctl(void) +static void register_sched_domain_sysctl(void) +{ +} +static void unregister_sched_domain_sysctl(void) { } #endif @@ -6311,6 +6333,8 @@ static int arch_init_sched_domains(const err = build_sched_domains(&cpu_default_map); + register_sched_domain_sysctl(); + return err; } @@ -6327,6 +6351,8 @@ static void detach_destroy_domains(const { int i; + unregister_sched_domain_sysctl(); + for_each_cpu_mask(i, *cpu_map) cpu_attach_domain(NULL, i); synchronize_sched(); @@ -6357,6 +6383,8 @@ int partition_sched_domains(cpumask_t *p if (!err && !cpus_empty(*partition2)) err = build_sched_domains(partition2); + register_sched_domain_sysctl(); + return err; } @@ -6488,8 +6516,6 @@ void __init sched_init_smp(void) /* XXX: Theoretical race here - CPU may be hotplugged now */ hotcpu_notifier(update_sched_domains, 0); - init_sched_domain_sysctl(); - /* Move init over to a non-isolated CPU */ if (set_cpus_allowed(current, non_isolated_cpus) < 0) BUG(); - 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/