From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755176AbXLFCGm (ORCPT ); Wed, 5 Dec 2007 21:06:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754616AbXLFCFW (ORCPT ); Wed, 5 Dec 2007 21:05:22 -0500 Received: from smtp.polymtl.ca ([132.207.4.11]:37984 "EHLO smtp.polymtl.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754594AbXLFCFT (ORCPT ); Wed, 5 Dec 2007 21:05:19 -0500 Message-Id: <20071206020442.877002841@polymtl.ca> References: <20071206020246.417605824@polymtl.ca> User-Agent: quilt/0.46-1 Date: Wed, 05 Dec 2007 21:02:53 -0500 From: Mathieu Desnoyers To: akpm@linux-foundation.org, Ingo Molnar , linux-kernel@vger.kernel.org Cc: Mathieu Desnoyers , Ananth N Mavinakayanahalli , prasanna@in.ibm.com, anil.s.keshavamurthy@intel.com, davem@davemloft.net, Roel Kluin <12o3l@tiscali.nl> Subject: [patch 07/11] Text Edit Lock - kprobes architecture independent support Content-Disposition: inline; filename=text-edit-lock-kprobes-architecture-independent.patch X-Poly-FromMTA: (dijkstra.casi.polymtl.ca [132.207.72.10]) at Thu, 6 Dec 2007 02:04:47 +0000 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Signed-off-by: Mathieu Desnoyers Acked-by: Ananth N Mavinakayanahalli CC: prasanna@in.ibm.com CC: ananth@in.ibm.com CC: anil.s.keshavamurthy@intel.com CC: davem@davemloft.net CC: Roel Kluin <12o3l@tiscali.nl> --- kernel/kprobes.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) Index: linux-2.6-lttng/kernel/kprobes.c =================================================================== --- linux-2.6-lttng.orig/kernel/kprobes.c 2007-11-16 13:40:06.000000000 -0500 +++ linux-2.6-lttng/kernel/kprobes.c 2007-11-17 10:00:23.000000000 -0500 @@ -43,6 +43,7 @@ #include #include #include +#include #include #include @@ -568,9 +569,10 @@ static int __kprobes __register_kprobe(s goto out; } + kernel_text_lock(); ret = arch_prepare_kprobe(p); if (ret) - goto out; + goto out_unlock_text; INIT_HLIST_NODE(&p->hlist); hlist_add_head_rcu(&p->hlist, @@ -578,7 +580,8 @@ static int __kprobes __register_kprobe(s if (kprobe_enabled) arch_arm_kprobe(p); - +out_unlock_text: + kernel_text_unlock(); out: mutex_unlock(&kprobe_mutex); @@ -621,8 +624,11 @@ valid_p: * enabled - otherwise, the breakpoint would already have * been removed. We save on flushing icache. */ - if (kprobe_enabled) + if (kprobe_enabled) { + kernel_text_lock(); arch_disarm_kprobe(p); + kernel_text_unlock(); + } hlist_del_rcu(&old_p->hlist); cleanup_p = 1; } else { @@ -644,9 +650,7 @@ valid_p: list_del_rcu(&p->list); kfree(old_p); } - mutex_lock(&kprobe_mutex); arch_remove_kprobe(p); - mutex_unlock(&kprobe_mutex); } else { mutex_lock(&kprobe_mutex); if (p->break_handler) @@ -717,7 +721,6 @@ static int __kprobes pre_handler_kretpro ri->rp = rp; ri->task = current; arch_prepare_kretprobe(ri, regs); - /* XXX(hch): why is there no hlist_move_head? */ hlist_del(&ri->uflist); hlist_add_head(&ri->uflist, &ri->rp->used_instances); @@ -938,11 +941,13 @@ static void __kprobes enable_all_kprobes if (kprobe_enabled) goto already_enabled; + kernel_text_lock(); for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, node, head, hlist) arch_arm_kprobe(p); } + kernel_text_unlock(); kprobe_enabled = true; printk(KERN_INFO "Kprobes globally enabled\n"); @@ -967,6 +972,7 @@ static void __kprobes disable_all_kprobe kprobe_enabled = false; printk(KERN_INFO "Kprobes globally disabled\n"); + kernel_text_lock(); for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, node, head, hlist) { @@ -974,6 +980,7 @@ static void __kprobes disable_all_kprobe arch_disarm_kprobe(p); } } + kernel_text_unlock(); mutex_unlock(&kprobe_mutex); /* Allow all currently running kprobes to complete */ -- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68