From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CAED3C432C3 for ; Fri, 22 Nov 2019 06:26:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9803A20714 for ; Fri, 22 Nov 2019 06:26:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574404009; bh=uI7WqOCmD7pPLkF6NG+fgAmT0gxRGJ+luTIViUcMrsI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NxugaU6rRnoUHSKwOE96UihwxOomT+MHkZOq6GxX+waYOyn2WIySoKhP+NxT+9ul7 VJ3ovRHAtFksAGSDlD42ti6oBc/G4NZQZbD4rDVB+PQAusItzmDXixehv3j5eqeUUf lfEzz8MChljPZ8PAJawVv7DnFIW+zZ6tw7SSIfMg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727350AbfKVG0p (ORCPT ); Fri, 22 Nov 2019 01:26:45 -0500 Received: from mail.kernel.org ([198.145.29.99]:55458 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727838AbfKVFun (ORCPT ); Fri, 22 Nov 2019 00:50:43 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 438B72070E; Fri, 22 Nov 2019 05:50:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574401842; bh=uI7WqOCmD7pPLkF6NG+fgAmT0gxRGJ+luTIViUcMrsI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KGDjY7nQu9Minmqz1bq32PtsP2TampjnWNqDlBYiruYMcuzW6wpVQmUdhkn6rEajJ 1aPFtxQPv18ylFajvJUvtJaioEHphSCtjy06UyFwFlMiFDuupziPwWIYcGZllMjgh1 OK/E1ugv4BrnOIhkKmWw4Kct2tktz0nb53cwXPug= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Masami Hiramatsu , Andrea Righi , Andy Lutomirski , Anil S Keshavamurthy , Borislav Petkov , "David S . Miller" , Linus Torvalds , "Naveen N . Rao" , Peter Zijlstra , Thomas Gleixner , Yonghong Song , Ingo Molnar , Sasha Levin Subject: [PATCH AUTOSEL 4.19 082/219] kprobes: Blacklist symbols in arch-defined prohibited area Date: Fri, 22 Nov 2019 00:46:54 -0500 Message-Id: <20191122054911.1750-75-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191122054911.1750-1-sashal@kernel.org> References: <20191122054911.1750-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Masami Hiramatsu [ Upstream commit fb1a59fae8baa3f3c69b72a87ff94fc4fa5683ec ] Blacklist symbols in arch-defined probe-prohibited areas. With this change, user can see all symbols which are prohibited to probe in debugfs. All archtectures which have custom prohibit areas should define its own arch_populate_kprobe_blacklist() function, but unless that, all symbols marked __kprobes are blacklisted. Reported-by: Andrea Righi Tested-by: Andrea Righi Signed-off-by: Masami Hiramatsu Cc: Andy Lutomirski Cc: Anil S Keshavamurthy Cc: Borislav Petkov Cc: David S. Miller Cc: Linus Torvalds Cc: Naveen N. Rao Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Yonghong Song Link: http://lkml.kernel.org/r/154503485491.26176.15823229545155174796.stgit@devbox Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- include/linux/kprobes.h | 3 ++ kernel/kprobes.c | 67 ++++++++++++++++++++++++++++++++--------- 2 files changed, 56 insertions(+), 14 deletions(-) diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 32cae0f35b9d4..9adb92ad24d3f 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -243,10 +243,13 @@ 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 arch_populate_kprobe_blacklist(void); extern bool arch_kprobe_on_func_entry(unsigned long offset); extern bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset); extern bool within_kprobe_blacklist(unsigned long addr); +extern int kprobe_add_ksym_blacklist(unsigned long entry); +extern int kprobe_add_area_blacklist(unsigned long start, unsigned long end); struct kprobe_insn_cache { struct mutex mutex; diff --git a/kernel/kprobes.c b/kernel/kprobes.c index b8efca9dc2cbb..c4f1acb2e7d20 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2090,6 +2090,47 @@ void dump_kprobe(struct kprobe *kp) } NOKPROBE_SYMBOL(dump_kprobe); +int kprobe_add_ksym_blacklist(unsigned long entry) +{ + struct kprobe_blacklist_entry *ent; + unsigned long offset = 0, size = 0; + + if (!kernel_text_address(entry) || + !kallsyms_lookup_size_offset(entry, &size, &offset)) + return -EINVAL; + + ent = kmalloc(sizeof(*ent), GFP_KERNEL); + if (!ent) + return -ENOMEM; + ent->start_addr = entry; + ent->end_addr = entry + size; + INIT_LIST_HEAD(&ent->list); + list_add_tail(&ent->list, &kprobe_blacklist); + + return (int)size; +} + +/* Add all symbols in given area into kprobe blacklist */ +int kprobe_add_area_blacklist(unsigned long start, unsigned long end) +{ + unsigned long entry; + int ret = 0; + + for (entry = start; entry < end; entry += ret) { + ret = kprobe_add_ksym_blacklist(entry); + if (ret < 0) + return ret; + if (ret == 0) /* In case of alias symbol */ + ret = 1; + } + return 0; +} + +int __init __weak arch_populate_kprobe_blacklist(void) +{ + return 0; +} + /* * Lookup and populate the kprobe_blacklist. * @@ -2101,26 +2142,24 @@ NOKPROBE_SYMBOL(dump_kprobe); static int __init populate_kprobe_blacklist(unsigned long *start, unsigned long *end) { + unsigned long entry; unsigned long *iter; - struct kprobe_blacklist_entry *ent; - unsigned long entry, offset = 0, size = 0; + int ret; for (iter = start; iter < end; iter++) { entry = arch_deref_entry_point((void *)*iter); - - if (!kernel_text_address(entry) || - !kallsyms_lookup_size_offset(entry, &size, &offset)) + ret = kprobe_add_ksym_blacklist(entry); + if (ret == -EINVAL) continue; - - ent = kmalloc(sizeof(*ent), GFP_KERNEL); - if (!ent) - return -ENOMEM; - ent->start_addr = entry; - ent->end_addr = entry + size; - INIT_LIST_HEAD(&ent->list); - list_add_tail(&ent->list, &kprobe_blacklist); + if (ret < 0) + return ret; } - return 0; + + /* Symbols in __kprobes_text are blacklisted */ + ret = kprobe_add_area_blacklist((unsigned long)__kprobes_text_start, + (unsigned long)__kprobes_text_end); + + return ret ? : arch_populate_kprobe_blacklist(); } /* Module notifier call back, checking kprobes on the module */ -- 2.20.1