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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 D0EE2C432C3 for ; Tue, 3 Dec 2019 22:51:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9EC8F214AF for ; Tue, 3 Dec 2019 22:51:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575413492; bh=PvrA4J+W8QBDfWcmIS4V90Fx1g6lwnCedsz7K6EiqCI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=caYGNP4VI+BmwOhMaBzAfeNWMWt6GHdxoaIDGlfRxhfXJI8Q58i8RF7qDinPYhoWX zEXCABIBUPzSj4wBJEHtmurnxHaz3LHt+ApWz76iqUnDN/t0H6RMR4l5l5GVVdHWqh HSjh7LS10YDy+lybWd4qP15Sakilgw5O1TF7MRE4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729903AbfLCWvb (ORCPT ); Tue, 3 Dec 2019 17:51:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:43558 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729882AbfLCWvZ (ORCPT ); Tue, 3 Dec 2019 17:51:25 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BFCCC21582; Tue, 3 Dec 2019 22:51:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575413484; bh=PvrA4J+W8QBDfWcmIS4V90Fx1g6lwnCedsz7K6EiqCI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZpVGuDXEwvfViMnoTSgc20IiAh/vlIYIMxMwLy1lEFQnOK7tOMWMgeXLdm+1S6zxT 4IeS139TTbn+27F35JZ56h9wJhzV8ad1ZsOhC/feoGS7iYulCJZ31JiyXMj2WzNbaT IKLmFyF4KSAMRdbuGOn60ffMRTne9guDBQ7hUr7w= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrea Righi , Masami Hiramatsu , 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 4.19 128/321] kprobes: Blacklist symbols in arch-defined prohibited area Date: Tue, 3 Dec 2019 23:33:14 +0100 Message-Id: <20191203223433.811052655@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191203223427.103571230@linuxfoundation.org> References: <20191203223427.103571230@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 aed90788db5c1..f4e4095ec7eae 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2096,6 +2096,47 @@ 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. * @@ -2107,26 +2148,24 @@ 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