Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755868AbZCCOdu (ORCPT ); Tue, 3 Mar 2009 09:33:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752313AbZCCOdk (ORCPT ); Tue, 3 Mar 2009 09:33:40 -0500 Received: from tomts40.bellnexxia.net ([209.226.175.97]:64063 "EHLO tomts40-srv.bellnexxia.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755154AbZCCOdj (ORCPT ); Tue, 3 Mar 2009 09:33:39 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AvsEALvJrElMQW1W/2dsb2JhbACBTtZQhAYG Date: Tue, 3 Mar 2009 09:33:33 -0500 From: Mathieu Desnoyers To: Ananth N Mavinakayanahalli , Ingo Molnar Cc: Peter Zijlstra , Masami Hiramatsu , Andrew Morton , Nick Piggin , Steven Rostedt , Andi Kleen , linux-kernel@vger.kernel.org, Thomas Gleixner , Peter Zijlstra , Frederic Weisbecker , Linus Torvalds , Arjan van de Ven , Rusty Russell , "H. Peter Anvin" , Steven Rostedt Subject: [PATCH] Text Edit Lock - kprobes architecture independent support (v3) Message-ID: <20090303143333.GB27043@Krystal> References: <20090302222254.GA31962@elte.hu> <49AC63FA.70801@redhat.com> <20090302230915.GA11626@elte.hu> <49AC6DEA.2050304@redhat.com> <20090302234910.GA17956@elte.hu> <20090303000054.GC3906@Krystal> <20090303003237.GA30221@elte.hu> <20090303013124.GB7783@Krystal> <20090303092750.GG11484@elte.hu> <20090303120659.GA3480@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <20090303120659.GA3480@in.ibm.com> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 09:31:17 up 3 days, 10:57, 1 user, load average: 0.03, 0.24, 0.31 User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3348 Lines: 108 Use the mutual exclusion provided by the text edit lock in the kprobes code. It allows coherent manipulation of the kernel code by other subsystems. Changelog: Move the kernel_text_lock/unlock out of the for loops. Use text_mutex directly instead of a function. Remove whitespace modifications. (note : kprobes_mutex is always taken outside of text_mutex) Signed-off-by: Mathieu Desnoyers Acked-by: Ananth N Mavinakayanahalli Acked-by: Masami Hiramatsu CC: ananth@in.ibm.com CC: anil.s.keshavamurthy@intel.com CC: davem@davemloft.net CC: Roel Kluin <12o3l@tiscali.nl> --- kernel/kprobes.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) Index: linux-2.6-lttng/kernel/kprobes.c =================================================================== --- linux-2.6-lttng.orig/kernel/kprobes.c 2009-03-02 19:22:51.000000000 -0500 +++ linux-2.6-lttng/kernel/kprobes.c 2009-03-03 09:11:17.000000000 -0500 @@ -43,6 +43,7 @@ #include #include #include +#include #include #include @@ -699,9 +700,10 @@ int __kprobes register_kprobe(struct kpr goto out; } + mutex_lock(&text_mutex); ret = arch_prepare_kprobe(p); if (ret) - goto out; + goto out_unlock_text; INIT_HLIST_NODE(&p->hlist); hlist_add_head_rcu(&p->hlist, @@ -710,6 +712,8 @@ int __kprobes register_kprobe(struct kpr if (kprobe_enabled) arch_arm_kprobe(p); +out_unlock_text: + mutex_unlock(&text_mutex); out: mutex_unlock(&kprobe_mutex); @@ -746,8 +750,11 @@ valid_p: * enabled and not gone - otherwise, the breakpoint would * already have been removed. We save on flushing icache. */ - if (kprobe_enabled && !kprobe_gone(old_p)) + if (kprobe_enabled && !kprobe_gone(old_p)) { + mutex_lock(&text_mutex); arch_disarm_kprobe(p); + mutex_unlock(&text_mutex); + } hlist_del_rcu(&old_p->hlist); } else { if (p->break_handler && !kprobe_gone(p)) @@ -1280,12 +1287,14 @@ static void __kprobes enable_all_kprobes if (kprobe_enabled) goto already_enabled; + mutex_lock(&text_mutex); for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, node, head, hlist) if (!kprobe_gone(p)) arch_arm_kprobe(p); } + mutex_unlock(&text_mutex); kprobe_enabled = true; printk(KERN_INFO "Kprobes globally enabled\n"); @@ -1310,6 +1319,7 @@ static void __kprobes disable_all_kprobe kprobe_enabled = false; printk(KERN_INFO "Kprobes globally disabled\n"); + mutex_lock(&text_mutex); for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, node, head, hlist) { @@ -1318,6 +1328,7 @@ static void __kprobes disable_all_kprobe } } + mutex_unlock(&text_mutex); mutex_unlock(&kprobe_mutex); /* Allow all currently running kprobes to complete */ synchronize_sched(); -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 -- 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/