From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753811Ab2FLWyv (ORCPT ); Tue, 12 Jun 2012 18:54:51 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:23293 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753612Ab2FLWya (ORCPT ); Tue, 12 Jun 2012 18:54:30 -0400 X-Authority-Analysis: v=2.0 cv=D8PF24tj c=1 sm=0 a=ZycB6UtQUfgMyuk2+PxD7w==:17 a=XQbtiDEiEegA:10 a=Ciwy3NGCPMMA:10 a=_SymJIx89xIA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=3nbZYyFuAAAA:8 a=VwQbUJbxAAAA:8 a=20KFwNOVAAAA:8 a=oGMlB6cnAAAA:8 a=VnNF1IyMAAAA:8 a=Z4Rwk6OoAAAA:8 a=pGLkceISAAAA:8 a=WoGK4d_3FuubdTwUpJUA:9 a=EvKJbDF4Ut8A:10 a=Zh68SRI7RUMA:10 a=jEp0ucaQiEUA:10 a=CY6gl2JlH4YA:10 a=jbrJJM5MRmoA:10 a=MSl-tDqOz04A:10 a=jeBq3FmKZ4MA:10 a=usbtaDLraoK7Febj:21 a=EzC1ys5tiW-Qnklw:21 a=ZycB6UtQUfgMyuk2+PxD7w==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.80.29 Message-Id: <20120612225426.396720897@goodmis.org> User-Agent: quilt/0.60-1 Date: Tue, 12 Jun 2012 18:43:36 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Masami Hiramatsu , Frederic Weisbecker , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Ananth N Mavinakayanahalli , "Frank Ch. Eigler" Subject: [RFC][PATCH 09/13 v2] kprobes: cleanup to separate probe-able check References: <20120612224327.426900129@goodmis.org> Content-Disposition: inline; filename=0009-kprobes-cleanup-to-separate-probe-able-check.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Masami Hiramatsu Separate probe-able address checking code from register_kprobe(). Link: http://lkml.kernel.org/r/20120605102820.27845.90133.stgit@localhost.localdomain Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Ananth N Mavinakayanahalli Cc: "Frank Ch. Eigler" Cc: Andrew Morton Cc: Frederic Weisbecker Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt --- kernel/kprobes.c | 82 ++++++++++++++++++++++++++++++------------------------ 1 file changed, 45 insertions(+), 37 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 7a8a122..6137fe3 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1313,67 +1313,80 @@ static inline int check_kprobe_rereg(struct kprobe *p) return ret; } -int __kprobes register_kprobe(struct kprobe *p) +static __kprobes int check_kprobe_address_safe(struct kprobe *p, + struct module **probed_mod) { int ret = 0; - struct kprobe *old_p; - struct module *probed_mod; - kprobe_opcode_t *addr; - - addr = kprobe_addr(p); - if (IS_ERR(addr)) - return PTR_ERR(addr); - p->addr = addr; - - ret = check_kprobe_rereg(p); - if (ret) - return ret; jump_label_lock(); preempt_disable(); + + /* Ensure it is not in reserved area nor out of text */ if (!kernel_text_address((unsigned long) p->addr) || in_kprobes_functions((unsigned long) p->addr) || ftrace_text_reserved(p->addr, p->addr) || jump_label_text_reserved(p->addr, p->addr)) { ret = -EINVAL; - goto cannot_probe; + goto out; } - /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ - p->flags &= KPROBE_FLAG_DISABLED; - - /* - * Check if are we probing a module. - */ - probed_mod = __module_text_address((unsigned long) p->addr); - if (probed_mod) { - /* Return -ENOENT if fail. */ - ret = -ENOENT; + /* Check if are we probing a module */ + *probed_mod = __module_text_address((unsigned long) p->addr); + if (*probed_mod) { /* * We must hold a refcount of the probed module while updating * its code to prohibit unexpected unloading. */ - if (unlikely(!try_module_get(probed_mod))) - goto cannot_probe; + if (unlikely(!try_module_get(*probed_mod))) { + ret = -ENOENT; + goto out; + } /* * If the module freed .init.text, we couldn't insert * kprobes in there. */ - if (within_module_init((unsigned long)p->addr, probed_mod) && - probed_mod->state != MODULE_STATE_COMING) { - module_put(probed_mod); - goto cannot_probe; + if (within_module_init((unsigned long)p->addr, *probed_mod) && + (*probed_mod)->state != MODULE_STATE_COMING) { + module_put(*probed_mod); + *probed_mod = NULL; + ret = -ENOENT; } - /* ret will be updated by following code */ } +out: preempt_enable(); jump_label_unlock(); + return ret; +} + +int __kprobes register_kprobe(struct kprobe *p) +{ + int ret; + struct kprobe *old_p; + struct module *probed_mod; + kprobe_opcode_t *addr; + + /* Adjust probe address from symbol */ + addr = kprobe_addr(p); + if (IS_ERR(addr)) + return PTR_ERR(addr); + p->addr = addr; + + ret = check_kprobe_rereg(p); + if (ret) + return ret; + + /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ + p->flags &= KPROBE_FLAG_DISABLED; p->nmissed = 0; INIT_LIST_HEAD(&p->list); - mutex_lock(&kprobe_mutex); + ret = check_kprobe_address_safe(p, &probed_mod); + if (ret) + return ret; + + mutex_lock(&kprobe_mutex); jump_label_lock(); /* needed to call jump_label_text_reserved() */ get_online_cpus(); /* For avoiding text_mutex deadlock. */ @@ -1410,11 +1423,6 @@ out: module_put(probed_mod); return ret; - -cannot_probe: - preempt_enable(); - jump_label_unlock(); - return ret; } EXPORT_SYMBOL_GPL(register_kprobe); -- 1.7.10