From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755998AbaDQIT0 (ORCPT ); Thu, 17 Apr 2014 04:19:26 -0400 Received: from mail4.hitachi.co.jp ([133.145.228.5]:33667 "EHLO mail4.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754077AbaDQITS (ORCPT ); Thu, 17 Apr 2014 04:19:18 -0400 Subject: [PATCH -tip v9 22/26] kprobes/x86: Use kprobe_blacklist for .kprobes.text and .entry.text From: Masami Hiramatsu To: linux-kernel@vger.kernel.org, Ingo Molnar Cc: Andi Kleen , Ananth N Mavinakayanahalli , Sandeepa Prabhu , Frederic Weisbecker , x86@kernel.org, Steven Rostedt , "David S. Miller" , fche@redhat.com, mingo@redhat.com, systemtap@sourceware.org, "H. Peter Anvin" , Andrew Morton , Thomas Gleixner Date: Thu, 17 Apr 2014 17:19:10 +0900 Message-ID: <20140417081910.26341.58385.stgit@ltc230.yrl.intra.hitachi.co.jp> In-Reply-To: <20140417081636.26341.87858.stgit@ltc230.yrl.intra.hitachi.co.jp> References: <20140417081636.26341.87858.stgit@ltc230.yrl.intra.hitachi.co.jp> User-Agent: StGit/0.17-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use kprobe_blackpoint for blacklisting .entry.text and .kprobees.text instead of arch_within_kprobe_blacklist. This also makes them visible via (debugfs)/kprobes/blacklist. Signed-off-by: Masami Hiramatsu Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Ananth N Mavinakayanahalli Cc: "David S. Miller" Cc: Steven Rostedt Cc: Andrew Morton --- arch/x86/kernel/kprobes/core.c | 11 +------ include/linux/kprobes.h | 1 + kernel/kprobes.c | 64 ++++++++++++++++++++++++++++------------ 3 files changed, 48 insertions(+), 28 deletions(-) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 1a92130..2fb3d3e 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1068,17 +1068,10 @@ int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) } NOKPROBE_SYMBOL(longjmp_break_handler); -bool arch_within_kprobe_blacklist(unsigned long addr) -{ - return (addr >= (unsigned long)__kprobes_text_start && - addr < (unsigned long)__kprobes_text_end) || - (addr >= (unsigned long)__entry_text_start && - addr < (unsigned long)__entry_text_end); -} - int __init arch_init_kprobes(void) { - return 0; + return kprobe_blacklist_add_range((unsigned long)__entry_text_start, + (unsigned long) __entry_text_end); } int arch_trampoline_kprobe(struct kprobe *p) diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index e059507..e81bced 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -266,6 +266,7 @@ extern int arch_init_kprobes(void); extern void show_registers(struct pt_regs *regs); extern void kprobes_inc_nmissed_count(struct kprobe *p); extern bool arch_within_kprobe_blacklist(unsigned long addr); +extern int kprobe_blacklist_add_range(unsigned long start, unsigned long end); struct kprobe_insn_cache { struct mutex mutex; diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 8319048..abdede5 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1325,13 +1325,6 @@ out: return ret; } -bool __weak arch_within_kprobe_blacklist(unsigned long addr) -{ - /* The __kprobes marked functions and entry code must not be probed */ - return addr >= (unsigned long)__kprobes_text_start && - addr < (unsigned long)__kprobes_text_end; -} - static struct kprobe_blacklist_entry *find_blacklist_entry(unsigned long addr) { struct kprobe_blacklist_entry *ent; @@ -1346,8 +1339,6 @@ static struct kprobe_blacklist_entry *find_blacklist_entry(unsigned long addr) static bool within_kprobe_blacklist(unsigned long addr) { - if (arch_within_kprobe_blacklist(addr)) - return true; /* * If there exists a kprobe_blacklist, verify and * fail any probe registration in the prohibited area @@ -2032,6 +2023,40 @@ void dump_kprobe(struct kprobe *kp) } NOKPROBE_SYMBOL(dump_kprobe); +static int __kprobe_blacklist_add(unsigned long start, unsigned long end) +{ + struct kprobe_blacklist_entry *ent; + + ent = kmalloc(sizeof(*ent), GFP_KERNEL); + if (!ent) + return -ENOMEM; + + ent->start_addr = start; + ent->end_addr = end; + INIT_LIST_HEAD(&ent->list); + list_add_tail(&ent->list, &kprobe_blacklist); + return 0; +} + +int kprobe_blacklist_add_range(unsigned long start, unsigned long end) +{ + unsigned long offset = 0, size = 0; + int err = 0; + + mutex_lock(&kprobe_blacklist_mutex); + while (!err && start < end) { + if (!kallsyms_lookup_size_offset(start, &size, &offset) || + size == 0) { + err = -ENOENT; + break; + } + err = __kprobe_blacklist_add(start, start + size); + start += size; + } + mutex_unlock(&kprobe_blacklist_mutex); + return err; +} + /* * Lookup and populate the kprobe_blacklist. * @@ -2043,8 +2068,8 @@ NOKPROBE_SYMBOL(dump_kprobe); static int populate_kprobe_blacklist(unsigned long *start, unsigned long *end) { unsigned long *iter; - struct kprobe_blacklist_entry *ent; unsigned long offset = 0, size = 0; + int ret; mutex_lock(&kprobe_blacklist_mutex); for (iter = start; iter < end; iter++) { @@ -2052,14 +2077,7 @@ static int populate_kprobe_blacklist(unsigned long *start, unsigned long *end) pr_err("Failed to find blacklist %p\n", (void *)*iter); continue; } - - ent = kmalloc(sizeof(*ent), GFP_KERNEL); - if (!ent) - return -ENOMEM; - ent->start_addr = *iter; - ent->end_addr = *iter + size; - INIT_LIST_HEAD(&ent->list); - list_add_tail(&ent->list, &kprobe_blacklist); + ret = __kprobe_blacklist_add(*iter, *iter + size); } mutex_unlock(&kprobe_blacklist_mutex); @@ -2154,7 +2172,15 @@ static int __init init_kprobes(void) err = populate_kprobe_blacklist(__start_kprobe_blacklist, __stop_kprobe_blacklist); - if (err) { + + if (err >= 0 && __kprobes_text_start != __kprobes_text_end) { + /* The __kprobes marked functions must not be probed */ + err = kprobe_blacklist_add_range( + (unsigned long)__kprobes_text_start, + (unsigned long)__kprobes_text_end); + } + + if (err < 0) { pr_err("kprobes: failed to populate blacklist: %d\n", err); pr_err("Please take care of using kprobes.\n"); }