From patchwork Wed May 26 08:02:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12280819 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 C62FFC47088 for ; Wed, 26 May 2021 08:02:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A43A2613E6 for ; Wed, 26 May 2021 08:02:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232915AbhEZID5 (ORCPT ); Wed, 26 May 2021 04:03:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:38990 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232812AbhEZID4 (ORCPT ); Wed, 26 May 2021 04:03:56 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5E4B7613D3; Wed, 26 May 2021 08:02:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622016145; bh=lruHPAWz+JCx1JmZ/0Vse4XTb21USc/CY1aMZrfI25g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SJd0Rk23zHcoI4KJ4yWdfJ/xU3z3lhlEVC5s0XCINOGDmbvZnW4erjhOFYAfL/wYk DnQXZ79DJr9SUf8OnY/76848Vvo6ukfk6u7pu+KQriN4bq99z6xsd9fILzSOCuiEm9 DBR11L8RllQHJyBsHo8sACGmT5FhWoyB19Hlf0iGaKIMUiORrkOnbvJhFCv1na1VKV P+vyCd53galgzKurW2iSM42FXBXcycr+WqIl//yLaITTSKKjBEIcpbr4bKa6UCJ4ze Xx0j27ickBYBR11hR6hmWO/0/bTVOv1sLwuXTcFQuUJTA2hLDlkOK53nfNBC95cGgc Ai3KVNnVC+1Kw== From: Masami Hiramatsu To: Steven Rostedt , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com, Josh Poimboeuf , linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: [PATCH -tip v6 01/13] ia64: kprobes: Fix to pass correct trampoline address to the handler Date: Wed, 26 May 2021 17:02:20 +0900 Message-Id: <162201614019.278331.4298879353454259298.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162201612941.278331.5293566981784464165.stgit@devnote2> References: <162201612941.278331.5293566981784464165.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Commit e792ff804f49 ("ia64: kprobes: Use generic kretprobe trampoline handler") missed to pass the wrong trampoline address (it passes the descriptor address instead of function entry address). This fixes it to pass correct trampoline address to __kretprobe_trampoline_handler(). This also changes to use correct symbol dereference function to get the function address from the kretprobe_trampoline. Fixes: e792ff804f49 ("ia64: kprobes: Use generic kretprobe trampoline handler") Signed-off-by: Masami Hiramatsu --- Changes in v5: - Fix a compile error typo. --- arch/ia64/kernel/kprobes.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index fc1ff8a4d7de..ca4b4fa45aef 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -398,7 +398,8 @@ static void kretprobe_trampoline(void) int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - regs->cr_iip = __kretprobe_trampoline_handler(regs, kretprobe_trampoline, NULL); + regs->cr_iip = __kretprobe_trampoline_handler(regs, + dereference_function_descriptor(kretprobe_trampoline), NULL); /* * By returning a non-zero value, we are telling * kprobe_handler() that we don't want the post_handler @@ -414,7 +415,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, ri->fp = NULL; /* Replace the return addr with trampoline addr */ - regs->b0 = ((struct fnptr *)kretprobe_trampoline)->ip; + regs->b0 = (unsigned long)dereference_function_descriptor(kretprobe_trampoline); } /* Check the instruction in the slot is break */ @@ -918,14 +919,14 @@ static struct kprobe trampoline_p = { int __init arch_init_kprobes(void) { trampoline_p.addr = - (kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip; + dereference_function_descriptor(kretprobe_trampoline); return register_kprobe(&trampoline_p); } int __kprobes arch_trampoline_kprobe(struct kprobe *p) { if (p->addr == - (kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip) + dereference_function_descriptor(kretprobe_trampoline)) return 1; return 0; From patchwork Wed May 26 08:02:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12280821 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 CF170C47088 for ; Wed, 26 May 2021 08:02:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B1FA66143E for ; Wed, 26 May 2021 08:02:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233081AbhEZIEO (ORCPT ); Wed, 26 May 2021 04:04:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:39178 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233136AbhEZIEG (ORCPT ); Wed, 26 May 2021 04:04:06 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7C5B1613E6; Wed, 26 May 2021 08:02:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622016155; bh=1LR3t2uaeaUn6d4R6+4K4m7Of/yVJ6Uf6xFqOl9YKNs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BMOrJB4tn/y1l40fhMAtrIhZaLEPwSayHaA5SM5LNvgztFsEJwxh3+DD0xa3T83k8 0pyGWgOQe52QwAY8NYmjIuiqAzxdvoC8fYibh8YwZ6INZkD+lzaKrmXF0V+D4Zldlv H8S/9bra9VL4UfQwmI9ERX/p7vH7xgnvGMXH9praZCi5WPNSEzejNA+r9fbIi3ukJx vxlRWtcl1p7CqDkarRUwJrIypI9/hzgkTMDAbP+KtPyjzaAVV7JtVZWr1viK1A561S IBo3suE9ycnE9XeIY2Q1FCe8fCa1NnRbAJmSBY9NPw7PuqkkJdIl3ljmqRbyJJwvJj 2KtAEXdzwZyfQ== From: Masami Hiramatsu To: Steven Rostedt , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com, Josh Poimboeuf , linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: [PATCH -tip v6 02/13] kprobes: treewide: Replace arch_deref_entry_point() with dereference_symbol_descriptor() Date: Wed, 26 May 2021 17:02:30 +0900 Message-Id: <162201615027.278331.16343511342536245353.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162201612941.278331.5293566981784464165.stgit@devnote2> References: <162201612941.278331.5293566981784464165.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Replace arch_deref_entry_point() with dereference_symbol_descriptor() because those are doing same thing. Signed-off-by: Masami Hiramatsu --- Changes in v6: - Use dereference_symbol_descriptor() so that it can handle address in modules correctly. --- arch/ia64/kernel/kprobes.c | 5 ----- arch/powerpc/kernel/kprobes.c | 11 ----------- include/linux/kprobes.h | 1 - kernel/kprobes.c | 7 +------ lib/error-inject.c | 3 ++- 5 files changed, 3 insertions(+), 24 deletions(-) diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index ca4b4fa45aef..eaf3c734719b 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -907,11 +907,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, return ret; } -unsigned long arch_deref_entry_point(void *entry) -{ - return ((struct fnptr *)entry)->ip; -} - static struct kprobe trampoline_p = { .pre_handler = trampoline_probe_handler }; diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 01ab2163659e..eb0460949e1b 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -539,17 +539,6 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr) } NOKPROBE_SYMBOL(kprobe_fault_handler); -unsigned long arch_deref_entry_point(void *entry) -{ -#ifdef PPC64_ELF_ABI_v1 - if (!kernel_text_address((unsigned long)entry)) - return ppc_global_function_entry(entry); - else -#endif - return (unsigned long)entry; -} -NOKPROBE_SYMBOL(arch_deref_entry_point); - static struct kprobe trampoline_p = { .addr = (kprobe_opcode_t *) &kretprobe_trampoline, .pre_handler = trampoline_probe_handler diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 1883a4a9f16a..d65c041b5c22 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -390,7 +390,6 @@ int register_kprobe(struct kprobe *p); void unregister_kprobe(struct kprobe *p); int register_kprobes(struct kprobe **kps, int num); void unregister_kprobes(struct kprobe **kps, int num); -unsigned long arch_deref_entry_point(void *); int register_kretprobe(struct kretprobe *rp); void unregister_kretprobe(struct kretprobe *rp); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 745f08fdd7a6..b2bb572173d4 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1856,11 +1856,6 @@ static struct notifier_block kprobe_exceptions_nb = { .priority = 0x7fffffff /* we need to be notified first */ }; -unsigned long __weak arch_deref_entry_point(void *entry) -{ - return (unsigned long)entry; -} - #ifdef CONFIG_KRETPROBES unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, @@ -2324,7 +2319,7 @@ static int __init populate_kprobe_blacklist(unsigned long *start, int ret; for (iter = start; iter < end; iter++) { - entry = arch_deref_entry_point((void *)*iter); + entry = (unsigned long)dereference_symbol_descriptor((void *)*iter); ret = kprobe_add_ksym_blacklist(entry); if (ret == -EINVAL) continue; diff --git a/lib/error-inject.c b/lib/error-inject.c index c73651b15b76..2ff5ef689d72 100644 --- a/lib/error-inject.c +++ b/lib/error-inject.c @@ -8,6 +8,7 @@ #include #include #include +#include /* Whitelist of symbols that can be overridden for error injection. */ static LIST_HEAD(error_injection_list); @@ -64,7 +65,7 @@ static void populate_error_injection_list(struct error_injection_entry *start, mutex_lock(&ei_mutex); for (iter = start; iter < end; iter++) { - entry = arch_deref_entry_point((void *)iter->addr); + entry = (unsigned long)dereference_symbol_descriptor((void *)iter->addr); if (!kernel_text_address(entry) || !kallsyms_lookup_size_offset(entry, &size, &offset)) { From patchwork Wed May 26 08:02:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12280823 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 A2BF5C2B9F7 for ; Wed, 26 May 2021 08:02:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 85F366143C for ; Wed, 26 May 2021 08:02:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233130AbhEZIER (ORCPT ); Wed, 26 May 2021 04:04:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:39360 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233133AbhEZIEP (ORCPT ); Wed, 26 May 2021 04:04:15 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0834B613B4; Wed, 26 May 2021 08:02:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622016164; bh=QNmQGHjul2YToQLw+Hszl9MqckBcWTzZQ/kw/2XdVpE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RXPVwyfgJppyJ/+BfdV7BYERJ7YILhESdtzrdvB0MzQ6jNK8Otm1NQA4VXZgwLjkQ HnOnBYOkyrKwFql/qY8VEl9YyS63vop/bk0tnNDQVYdPS4lE5sk+df+TIixv/ScjB1 CiBUniC8bQeHfrqTwzOZaD6e2pLc+Tay2dPy942D5sKBIDaouceYoNMP7t2guYut8d MYoJoj8131AEQQHybwDs0acHAVdAhk49NKDzmFj08AP9VyycCnBdrQMlmMR26uMi+h w0P9ksBisyMjI85pJtD1D9wHhWn1H73X2WHZnYQUPMe/4maPlh8o+Eax/SLuK+OMO6 N97hVUXY32fZQ== From: Masami Hiramatsu To: Steven Rostedt , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com, Josh Poimboeuf , linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: [PATCH -tip v6 03/13] kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler() Date: Wed, 26 May 2021 17:02:40 +0900 Message-Id: <162201616029.278331.9099129848055614515.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162201612941.278331.5293566981784464165.stgit@devnote2> References: <162201612941.278331.5293566981784464165.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Remove trampoline_address from kretprobe_trampoline_handler(). Instead of passing the address, kretprobe_trampoline_handler() can use new kretprobe_trampoline_addr(). Signed-off-by: Masami Hiramatsu --- Changes in v3: - Remove wrong kretprobe_trampoline declaration from arch/x86/include/asm/kprobes.h. Changes in v2: - Remove arch_deref_entry_point() from comment. --- arch/arc/kernel/kprobes.c | 2 +- arch/arm/probes/kprobes/core.c | 3 +-- arch/arm64/kernel/probes/kprobes.c | 3 +-- arch/csky/kernel/probes/kprobes.c | 2 +- arch/ia64/kernel/kprobes.c | 5 ++--- arch/mips/kernel/kprobes.c | 3 +-- arch/parisc/kernel/kprobes.c | 4 ++-- arch/powerpc/kernel/kprobes.c | 2 +- arch/riscv/kernel/probes/kprobes.c | 2 +- arch/s390/kernel/kprobes.c | 2 +- arch/sh/kernel/kprobes.c | 2 +- arch/sparc/kernel/kprobes.c | 2 +- arch/x86/include/asm/kprobes.h | 1 - arch/x86/kernel/kprobes/core.c | 2 +- include/linux/kprobes.h | 18 +++++++++++++----- kernel/kprobes.c | 3 +-- 16 files changed, 29 insertions(+), 27 deletions(-) diff --git a/arch/arc/kernel/kprobes.c b/arch/arc/kernel/kprobes.c index cabef45f11df..3ae01bb5820c 100644 --- a/arch/arc/kernel/kprobes.c +++ b/arch/arc/kernel/kprobes.c @@ -397,7 +397,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, static int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - regs->ret = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); + regs->ret = __kretprobe_trampoline_handler(regs, NULL); /* By returning a non zero value, we are telling the kprobe handler * that we don't want the post_handler to run diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c index a9653117ca0d..1782b41df095 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -413,8 +413,7 @@ void __naked __kprobes kretprobe_trampoline(void) /* Called from kretprobe_trampoline */ static __used __kprobes void *trampoline_handler(struct pt_regs *regs) { - return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, - (void *)regs->ARM_fp); + return (void *)kretprobe_trampoline_handler(regs, (void *)regs->ARM_fp); } void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index d607c9912025..813794f5636e 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -413,8 +413,7 @@ int __init arch_populate_kprobe_blacklist(void) void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs) { - return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, - (void *)kernel_stack_pointer(regs)); + return (void *)kretprobe_trampoline_handler(regs, (void *)kernel_stack_pointer(regs)); } void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, diff --git a/arch/csky/kernel/probes/kprobes.c b/arch/csky/kernel/probes/kprobes.c index 589f090f48b9..cc589bc11904 100644 --- a/arch/csky/kernel/probes/kprobes.c +++ b/arch/csky/kernel/probes/kprobes.c @@ -404,7 +404,7 @@ int __init arch_populate_kprobe_blacklist(void) void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs) { - return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); + return (void *)kretprobe_trampoline_handler(regs, NULL); } void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index eaf3c734719b..0204953a06cf 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -392,14 +392,13 @@ static void __kprobes set_current_kprobe(struct kprobe *p, __this_cpu_write(current_kprobe, p); } -static void kretprobe_trampoline(void) +void kretprobe_trampoline(void) { } int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - regs->cr_iip = __kretprobe_trampoline_handler(regs, - dereference_function_descriptor(kretprobe_trampoline), NULL); + regs->cr_iip = __kretprobe_trampoline_handler(regs, NULL); /* * By returning a non-zero value, we are telling * kprobe_handler() that we don't want the post_handler diff --git a/arch/mips/kernel/kprobes.c b/arch/mips/kernel/kprobes.c index 54dfba8fa77c..001a2f07ef44 100644 --- a/arch/mips/kernel/kprobes.c +++ b/arch/mips/kernel/kprobes.c @@ -489,8 +489,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, static int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - instruction_pointer(regs) = __kretprobe_trampoline_handler(regs, - kretprobe_trampoline, NULL); + instruction_pointer(regs) = __kretprobe_trampoline_handler(regs, NULL); /* * By returning a non-zero value, we are telling * kprobe_handler() that we don't want the post_handler diff --git a/arch/parisc/kernel/kprobes.c b/arch/parisc/kernel/kprobes.c index 6d21a515eea5..4a35ac6e2ca2 100644 --- a/arch/parisc/kernel/kprobes.c +++ b/arch/parisc/kernel/kprobes.c @@ -175,7 +175,7 @@ int __kprobes parisc_kprobe_ss_handler(struct pt_regs *regs) return 1; } -static inline void kretprobe_trampoline(void) +void kretprobe_trampoline(void) { asm volatile("nop"); asm volatile("nop"); @@ -193,7 +193,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, { unsigned long orig_ret_address; - orig_ret_address = __kretprobe_trampoline_handler(regs, trampoline_p.addr, NULL); + orig_ret_address = __kretprobe_trampoline_handler(regs, NULL); instruction_pointer_set(regs, orig_ret_address); return 1; diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index eb0460949e1b..dfd532c43525 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -399,7 +399,7 @@ static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { unsigned long orig_ret_address; - orig_ret_address = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); + orig_ret_address = __kretprobe_trampoline_handler(regs, NULL); /* * We get here through one of two paths: * 1. by taking a trap -> kprobe_handler() -> here diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c index 10b965c34536..a1e4fce1604b 100644 --- a/arch/riscv/kernel/probes/kprobes.c +++ b/arch/riscv/kernel/probes/kprobes.c @@ -385,7 +385,7 @@ int __init arch_populate_kprobe_blacklist(void) void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs) { - return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); + return (void *)kretprobe_trampoline_handler(regs, NULL); } void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c index aae24dc75df6..b149e9169709 100644 --- a/arch/s390/kernel/kprobes.c +++ b/arch/s390/kernel/kprobes.c @@ -351,7 +351,7 @@ static void __used kretprobe_trampoline_holder(void) */ static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - regs->psw.addr = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); + regs->psw.addr = __kretprobe_trampoline_handler(regs, NULL); /* * By returning a non-zero value, we are telling * kprobe_handler() that we don't want the post_handler diff --git a/arch/sh/kernel/kprobes.c b/arch/sh/kernel/kprobes.c index 756100b01e84..48356e81836a 100644 --- a/arch/sh/kernel/kprobes.c +++ b/arch/sh/kernel/kprobes.c @@ -303,7 +303,7 @@ static void __used kretprobe_trampoline_holder(void) */ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - regs->pc = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); + regs->pc = __kretprobe_trampoline_handler(regs, NULL); return 1; } diff --git a/arch/sparc/kernel/kprobes.c b/arch/sparc/kernel/kprobes.c index 217c21a6986a..fa30f9dadff8 100644 --- a/arch/sparc/kernel/kprobes.c +++ b/arch/sparc/kernel/kprobes.c @@ -468,7 +468,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, { unsigned long orig_ret_address = 0; - orig_ret_address = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); + orig_ret_address = __kretprobe_trampoline_handler(regs, NULL); regs->tpc = orig_ret_address; regs->tnpc = orig_ret_address + 4; diff --git a/arch/x86/include/asm/kprobes.h b/arch/x86/include/asm/kprobes.h index bd7f5886a789..71ea2eab43d5 100644 --- a/arch/x86/include/asm/kprobes.h +++ b/arch/x86/include/asm/kprobes.h @@ -49,7 +49,6 @@ extern __visible kprobe_opcode_t optprobe_template_end[]; extern const int kretprobe_blacklist_size; void arch_remove_kprobe(struct kprobe *p); -asmlinkage void kretprobe_trampoline(void); extern void arch_kprobe_override_function(struct pt_regs *regs); diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 7c4d0736a998..d32b09ca3221 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1070,7 +1070,7 @@ __used __visible void *trampoline_handler(struct pt_regs *regs) regs->ip = (unsigned long)&kretprobe_trampoline; regs->orig_ax = ~0UL; - return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, ®s->sp); + return (void *)kretprobe_trampoline_handler(regs, ®s->sp); } NOKPROBE_SYMBOL(trampoline_handler); diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index d65c041b5c22..65dadd4238a2 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -205,15 +205,23 @@ extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs); extern int arch_trampoline_kprobe(struct kprobe *p); +void kretprobe_trampoline(void); +/* + * Since some architecture uses structured function pointer, + * use dereference_function_descriptor() to get real function address. + */ +static nokprobe_inline void *kretprobe_trampoline_addr(void) +{ + return dereference_function_descriptor(kretprobe_trampoline); +} + /* If the trampoline handler called from a kprobe, use this version */ unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, - void *trampoline_address, - void *frame_pointer); + void *frame_pointer); static nokprobe_inline unsigned long kretprobe_trampoline_handler(struct pt_regs *regs, - void *trampoline_address, - void *frame_pointer) + void *frame_pointer) { unsigned long ret; /* @@ -222,7 +230,7 @@ unsigned long kretprobe_trampoline_handler(struct pt_regs *regs, * be running at this point. */ kprobe_busy_begin(); - ret = __kretprobe_trampoline_handler(regs, trampoline_address, frame_pointer); + ret = __kretprobe_trampoline_handler(regs, frame_pointer); kprobe_busy_end(); return ret; diff --git a/kernel/kprobes.c b/kernel/kprobes.c index b2bb572173d4..1d3087b59522 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1859,7 +1859,6 @@ static struct notifier_block kprobe_exceptions_nb = { #ifdef CONFIG_KRETPROBES unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, - void *trampoline_address, void *frame_pointer) { kprobe_opcode_t *correct_ret_addr = NULL; @@ -1874,7 +1873,7 @@ unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, BUG_ON(ri->fp != frame_pointer); - if (ri->ret_addr != trampoline_address) { + if (ri->ret_addr != kretprobe_trampoline_addr()) { correct_ret_addr = ri->ret_addr; /* * This is the real return address. Any other From patchwork Wed May 26 08:02:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12280825 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 1DBF2C2B9F7 for ; Wed, 26 May 2021 08:03:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDA126143F for ; Wed, 26 May 2021 08:02:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233186AbhEZIEa (ORCPT ); Wed, 26 May 2021 04:04:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:39646 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233203AbhEZIE0 (ORCPT ); Wed, 26 May 2021 04:04:26 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 992CF613D3; Wed, 26 May 2021 08:02:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622016175; bh=pN3nre/DipyPs1HgWnglyStaYza1lpZimOKga/iHd18=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V23NUescLjkgz9UL96Z3nXqnsg/De/tuNHJZbwveu2TRpNCNrq40YcR4enARLQRL9 QJC9imJyzhvCbyyyYiAiqwPDXNrJge/s5AH0phv4usJytm7X9dX0tAFIm0wSJzOglx wwN4oDECWhVcVZ9oitRINvJR/I0zT7pWZF4/XvjynOoqpInpc1uKIwmYxsd1HEu3JC 05LlcMXvJHzzsv1/7aCInOePPuQ8NbxWlok1gVn962xCZzFXPsoaqBru2UrT80CFIl lbaM8kEywqnVxeNdVqlNNR9kyp7kFlHvD0WgF/BBCmAJllepMNSKBju4MJTcuEeyOw UT2YxhMW4E9IQ== From: Masami Hiramatsu To: Steven Rostedt , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com, Josh Poimboeuf , linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: [PATCH -tip v6 04/13] kprobes: Add kretprobe_find_ret_addr() for searching return address Date: Wed, 26 May 2021 17:02:50 +0900 Message-Id: <162201616980.278331.4250834377953360353.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162201612941.278331.5293566981784464165.stgit@devnote2> References: <162201612941.278331.5293566981784464165.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add kretprobe_find_ret_addr() for searching correct return address from kretprobe instance list. Signed-off-by: Masami Hiramatsu --- Changes in v6: - Replace BUG_ON() with WARN_ON_ONCE() in __kretprobe_trampoline_handler(). Changes in v3: - Remove generic stacktrace fixup. Instead, it should be solved in each unwinder. This just provide the generic interface. Changes in v2: - Add is_kretprobe_trampoline() for checking address outside of kretprobe_find_ret_addr() - Remove unneeded addr from kretprobe_find_ret_addr() - Rename fixup_kretprobe_tramp_addr() to fixup_kretprobe_trampoline() --- include/linux/kprobes.h | 22 +++++++++++ kernel/kprobes.c | 91 ++++++++++++++++++++++++++++++++++------------- 2 files changed, 87 insertions(+), 26 deletions(-) diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 65dadd4238a2..f530f82a046d 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -215,6 +215,14 @@ static nokprobe_inline void *kretprobe_trampoline_addr(void) return dereference_function_descriptor(kretprobe_trampoline); } +static nokprobe_inline bool is_kretprobe_trampoline(unsigned long addr) +{ + return (void *)addr == kretprobe_trampoline_addr(); +} + +unsigned long kretprobe_find_ret_addr(struct task_struct *tsk, void *fp, + struct llist_node **cur); + /* If the trampoline handler called from a kprobe, use this version */ unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, void *frame_pointer); @@ -514,6 +522,20 @@ static inline bool is_kprobe_optinsn_slot(unsigned long addr) } #endif +#if !defined(CONFIG_KRETPROBES) +static nokprobe_inline bool is_kretprobe_trampoline(unsigned long addr) +{ + return false; +} + +static nokprobe_inline +unsigned long kretprobe_find_ret_addr(struct task_struct *tsk, void *fp, + struct llist_node **cur) +{ + return 0; +} +#endif + /* Returns true if kprobes handled the fault */ static nokprobe_inline bool kprobe_page_fault(struct pt_regs *regs, unsigned int trap) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 1d3087b59522..54e5b89aad67 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1858,45 +1858,69 @@ static struct notifier_block kprobe_exceptions_nb = { #ifdef CONFIG_KRETPROBES -unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, - void *frame_pointer) +/* This assumes the tsk is current or the task which is not running. */ +static unsigned long __kretprobe_find_ret_addr(struct task_struct *tsk, + struct llist_node **cur) { - kprobe_opcode_t *correct_ret_addr = NULL; struct kretprobe_instance *ri = NULL; - struct llist_node *first, *node; - struct kretprobe *rp; + struct llist_node *node = *cur; + + if (!node) + node = tsk->kretprobe_instances.first; + else + node = node->next; - /* Find all nodes for this frame. */ - first = node = current->kretprobe_instances.first; while (node) { ri = container_of(node, struct kretprobe_instance, llist); - - BUG_ON(ri->fp != frame_pointer); - if (ri->ret_addr != kretprobe_trampoline_addr()) { - correct_ret_addr = ri->ret_addr; - /* - * This is the real return address. Any other - * instances associated with this task are for - * other calls deeper on the call stack - */ - goto found; + *cur = node; + return (unsigned long)ri->ret_addr; } - node = node->next; } - pr_err("Oops! Kretprobe fails to find correct return address.\n"); - BUG_ON(1); + return 0; +} +NOKPROBE_SYMBOL(__kretprobe_find_ret_addr); -found: - /* Unlink all nodes for this frame. */ - current->kretprobe_instances.first = node->next; - node->next = NULL; +unsigned long kretprobe_find_ret_addr(struct task_struct *tsk, void *fp, + struct llist_node **cur) +{ + struct kretprobe_instance *ri = NULL; + unsigned long ret; + + do { + ret = __kretprobe_find_ret_addr(tsk, cur); + if (!ret) + return ret; + ri = container_of(*cur, struct kretprobe_instance, llist); + } while (ri->fp != fp); + + return ret; +} +NOKPROBE_SYMBOL(kretprobe_find_ret_addr); - /* Run them.. */ +unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, + void *frame_pointer) +{ + kprobe_opcode_t *correct_ret_addr = NULL; + struct kretprobe_instance *ri = NULL; + struct llist_node *first, *node = NULL; + struct kretprobe *rp; + + /* Find correct address and all nodes for this frame. */ + correct_ret_addr = (void *)__kretprobe_find_ret_addr(current, &node); + if (!correct_ret_addr) { + pr_err("Oops! Kretprobe fails to find correct return address.\n"); + BUG_ON(1); + } + + /* Run them. */ + first = current->kretprobe_instances.first; while (first) { ri = container_of(first, struct kretprobe_instance, llist); - first = first->next; + + if (WARN_ON_ONCE(ri->fp != frame_pointer)) + break; rp = get_kretprobe(ri); if (rp && rp->handler) { @@ -1907,6 +1931,21 @@ unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, rp->handler(ri, regs); __this_cpu_write(current_kprobe, prev); } + if (first == node) + break; + + first = first->next; + } + + /* Unlink all nodes for this frame. */ + first = current->kretprobe_instances.first; + current->kretprobe_instances.first = node->next; + node->next = NULL; + + /* Recycle them. */ + while (first) { + ri = container_of(first, struct kretprobe_instance, llist); + first = first->next; recycle_rp_inst(ri); } From patchwork Wed May 26 08:03:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12280827 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 A5865C2B9F7 for ; Wed, 26 May 2021 08:03:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 896006143C for ; Wed, 26 May 2021 08:03:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232854AbhEZIEm (ORCPT ); Wed, 26 May 2021 04:04:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:39798 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233221AbhEZIEg (ORCPT ); Wed, 26 May 2021 04:04:36 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B0B46613E6; Wed, 26 May 2021 08:03:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622016185; bh=5U6gnRUEzaqQIkCP8wcc1KtYEL1lDPSvMCtG2RgQz88=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nc33AMMFESxZKrv9ARLJmoycJenzTlk0F/V/siGES0Msaxp4qmzb4TjkzvWn4KPPN 28dCwK3LA4KaAxgDO5snTBMaEMHYIZPaQlUNuG9biJgN7eJu/+RmMOmxRUnAd+y+n1 6fcI0TfoRQQPDo8oblQBzLiJEd0FD2rhd/xATn8z9Nk2nLhPM+Xr+hopkgvBUc5W3H HlvtLRmKv0tkcUe9Lzn21C1eIPP/GNVOpo6O0Y4D+FVJQA48hhFnD8ghG5UJPYJe/A qoeiktG9bBgXm+/x+NWonjw660oOekukxrxBlE/I0qAaaDheyPcl2E7BTJYYZncNhn uv1uWwr/HTazw== From: Masami Hiramatsu To: Steven Rostedt , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com, Josh Poimboeuf , linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: [PATCH -tip v6 05/13] x86/kprobes: Add UNWIND_HINT_FUNC on kretprobe_trampoline code Date: Wed, 26 May 2021 17:03:00 +0900 Message-Id: <162201618061.278331.13571474279522709453.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162201612941.278331.5293566981784464165.stgit@devnote2> References: <162201612941.278331.5293566981784464165.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Josh Poimboeuf Add UNWIND_HINT_FUNC on kretporbe_trampoline code so that ORC information is generated on the kretprobe_trampoline correctly. Note that when the CONFIG_FRAME_POINTER=y, since the kretprobe_trampoline skips updating frame pointer, the stack frame of the kretprobe_trampoline seems non-standard. So this marks it is STACK_FRAME_NON_STANDARD() and undefine UNWIND_HINT_FUNC. Anyway, with the frame pointer, FP unwinder can unwind the stack frame correctly without that hint. Signed-off-by: Josh Poimboeuf Signed-off-by: Masami Hiramatsu --- Changes in v4: - Apply UNWIND_HINT_FUNC only if CONFIG_FRAME_POINTER=n. --- arch/x86/include/asm/unwind_hints.h | 5 +++++ arch/x86/kernel/kprobes/core.c | 17 +++++++++++++++-- 2 files changed, 20 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/unwind_hints.h b/arch/x86/include/asm/unwind_hints.h index 8e574c0afef8..8b33674288ea 100644 --- a/arch/x86/include/asm/unwind_hints.h +++ b/arch/x86/include/asm/unwind_hints.h @@ -52,6 +52,11 @@ UNWIND_HINT sp_reg=ORC_REG_SP sp_offset=8 type=UNWIND_HINT_TYPE_FUNC .endm +#else + +#define UNWIND_HINT_FUNC \ + UNWIND_HINT(ORC_REG_SP, 8, UNWIND_HINT_TYPE_FUNC, 0) + #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_UNWIND_HINTS_H */ diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index d32b09ca3221..9a6763fd066e 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1019,6 +1019,19 @@ int kprobe_int3_handler(struct pt_regs *regs) } NOKPROBE_SYMBOL(kprobe_int3_handler); +#ifdef CONFIG_FRAME_POINTER +/* + * kretprobe_trampoline skips updating frame pointer. The frame pointer + * saved in trampoline_handler points to the real caller function's + * frame pointer. Thus the kretprobe_trampoline doesn't seems to have a + * standard stack frame with CONFIG_FRAME_POINTER=y. + * Let's mark it non-standard function. Anyway, FP unwinder can correctly + * unwind without the hint. + */ +STACK_FRAME_NON_STANDARD(kretprobe_trampoline); +#undef UNWIND_HINT_FUNC +#define UNWIND_HINT_FUNC +#endif /* * When a retprobed function returns, this code saves registers and * calls trampoline_handler() runs, which calls the kretprobe's handler. @@ -1031,6 +1044,7 @@ asm( /* We don't bother saving the ss register */ #ifdef CONFIG_X86_64 " pushq %rsp\n" + UNWIND_HINT_FUNC " pushfq\n" SAVE_REGS_STRING " movq %rsp, %rdi\n" @@ -1041,6 +1055,7 @@ asm( " popfq\n" #else " pushl %esp\n" + UNWIND_HINT_FUNC " pushfl\n" SAVE_REGS_STRING " movl %esp, %eax\n" @@ -1054,8 +1069,6 @@ asm( ".size kretprobe_trampoline, .-kretprobe_trampoline\n" ); NOKPROBE_SYMBOL(kretprobe_trampoline); -STACK_FRAME_NON_STANDARD(kretprobe_trampoline); - /* * Called from kretprobe_trampoline From patchwork Wed May 26 08:03:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12280829 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 88559C2B9F7 for ; Wed, 26 May 2021 08:03:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66F9D613D3 for ; Wed, 26 May 2021 08:03:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233117AbhEZIEw (ORCPT ); Wed, 26 May 2021 04:04:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:39950 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233125AbhEZIEq (ORCPT ); Wed, 26 May 2021 04:04:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id DD3E36143C; Wed, 26 May 2021 08:03:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622016195; bh=KEe5WdEyJHtzuPMGzpiocUmfrX3xOnunn5dZvpKwBh8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DnVJbwPg6/PHpv6+3Vty4CWCzNAcoi/HjE84+vLrfOnDn+6Qn+xJBBuLErX/Ojc40 Gcn0mw24OvXKa6WWti+m/bqFIokt6GqZqg1tbMUQI/A9rfbbNQaikaSQYz714L57Az YEOWc9de7mKRdTx3/2snzb948yGNbOTZ7TnU2Q4Xa5dLyDEQl2Btsonl8zAz6gIF94 fQF0j4Ub7auJNj1ims2N/vuZUsfegciVi/o1SGLWW1ydolMr8lisO/Vy+cD5Catuz6 8Ph6KFrH8fKJVvB07ktJuXu4yodA5mwSgxmEAcm/DgJheDEHxY5Eosdn2mTpj8hzIz c153z3YoAUm6Q== From: Masami Hiramatsu To: Steven Rostedt , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com, Josh Poimboeuf , linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: [PATCH -tip v6 06/13] ARC: Add instruction_pointer_set() API Date: Wed, 26 May 2021 17:03:11 +0900 Message-Id: <162201619065.278331.10638125156640651686.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162201612941.278331.5293566981784464165.stgit@devnote2> References: <162201612941.278331.5293566981784464165.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add instruction_pointer_set() API for arc. Signed-off-by: Masami Hiramatsu --- arch/arc/include/asm/ptrace.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arc/include/asm/ptrace.h b/arch/arc/include/asm/ptrace.h index 4c3c9be5bd16..cca8d6583e31 100644 --- a/arch/arc/include/asm/ptrace.h +++ b/arch/arc/include/asm/ptrace.h @@ -149,6 +149,11 @@ static inline long regs_return_value(struct pt_regs *regs) return (long)regs->r0; } +static inline void instruction_pointer_set(struct pt_regs *regs, + unsigned long val) +{ + instruction_pointer(regs) = val; +} #endif /* !__ASSEMBLY__ */ #endif /* __ASM_PTRACE_H */ From patchwork Wed May 26 08:03:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12280831 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 2C38AC2B9F7 for ; Wed, 26 May 2021 08:03:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 09DBE613D3 for ; Wed, 26 May 2021 08:03:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233203AbhEZIE6 (ORCPT ); Wed, 26 May 2021 04:04:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:40130 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233182AbhEZIE4 (ORCPT ); Wed, 26 May 2021 04:04:56 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9286A613B4; Wed, 26 May 2021 08:03:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622016205; bh=eXubxiP2sfbDRxWXxCS2276qipPi7ZT+e19fUSeI+18=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D5+2YpNmlahnB9R6m+bJpzlYWgb9pI1aEDaazkf/ybA3v/F8WI3CW3hmaV/rPQbye 3W5opqFPKNOJvcqzHtaKQs9LWgBtWWB8g+ITBLX2RVMKf5/unwjApC0STvVCLsmnD3 +0piPvSOXfMYCMzkMedfB+yOaspR+X2XrSYcay8pS6LMJevthgmwyq71jCrJdP0gxB VFYf+MR63kCSYraVxdfo2hF59QtOTILQ0BBwVElBI167nkj0Cjr9ESFiU7rv1FE1oz vnJvFqEhOU+HTyweqSTt787EmwfSMuzL1BaD/b1rdbpfZIcBif3EivCepmfx9HxzRp fYXw5X7hgTgeg== From: Masami Hiramatsu To: Steven Rostedt , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com, Josh Poimboeuf , linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: [PATCH -tip v6 07/13] ia64: Add instruction_pointer_set() API Date: Wed, 26 May 2021 17:03:20 +0900 Message-Id: <162201620051.278331.3631153829513157789.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162201612941.278331.5293566981784464165.stgit@devnote2> References: <162201612941.278331.5293566981784464165.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add instruction_pointer_set() API for ia64. Signed-off-by: Masami Hiramatsu --- Changes in v4: - Make the API macro for avoiding a build error. --- arch/ia64/include/asm/ptrace.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/ia64/include/asm/ptrace.h b/arch/ia64/include/asm/ptrace.h index 08179135905c..a024afbc70e5 100644 --- a/arch/ia64/include/asm/ptrace.h +++ b/arch/ia64/include/asm/ptrace.h @@ -51,6 +51,11 @@ * the canonical representation by adding to instruction pointer. */ # define instruction_pointer(regs) ((regs)->cr_iip + ia64_psr(regs)->ri) +# define instruction_pointer_set(regs, val) \ + ({ \ + ia64_psr(regs)->ri = (val & 0xf); \ + regs->cr_iip = (val & ~0xfULL); \ + }) static inline unsigned long user_stack_pointer(struct pt_regs *regs) { From patchwork Wed May 26 08:03:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12280833 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 8D819C2B9F7 for ; Wed, 26 May 2021 08:03:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6A1D561443 for ; Wed, 26 May 2021 08:03:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233223AbhEZIFH (ORCPT ); Wed, 26 May 2021 04:05:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:40296 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233182AbhEZIFG (ORCPT ); Wed, 26 May 2021 04:05:06 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 18DCF613E6; Wed, 26 May 2021 08:03:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622016215; bh=KJfN3dfQ7CgYxygr2eqTq1OdnbRKmnmwZLg3RsPDjzE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kkbZNFAlElCzi6LGQjjUJQU/iCNABwBGAgnA/kH6P9ZdVZD/h7NnkSZaimEUKHkJS OxLR8zNwBfaLPF10N38fRqWvzy6IeSpVybUsnABMZ7/PVSykXDB5t/pjQNQOpBfXJD rKXnCovY/UFLuYkbpH8WWb0Xn5rJ+ZCacSbVADDGA9umdIMAmyjgFZzfAuy6h23lnL n5/2CMpdMd3xAuf5N2boJpUawDOQNLSv1K3EMEhGPShTiWoGfaHcOuvcrSFF7Qb8aP 7o+jVfujFLtL0mgziFzeOvB4vT/AC1DFeKhWcxCiqaFablB2Vdv3GgKi9Tga5m+dvc RheKmaiYbixAQ== From: Masami Hiramatsu To: Steven Rostedt , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com, Josh Poimboeuf , linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: [PATCH -tip v6 08/13] arm: kprobes: Make a space for regs->ARM_pc at kretprobe_trampoline Date: Wed, 26 May 2021 17:03:31 +0900 Message-Id: <162201621112.278331.7300612749929513135.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162201612941.278331.5293566981784464165.stgit@devnote2> References: <162201612941.278331.5293566981784464165.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Change kretprobe_trampoline to make a space for regs->ARM_pc so that kretprobe_trampoline_handler can call instruction_pointer_set() safely. Signed-off-by: Masami Hiramatsu --- arch/arm/probes/kprobes/core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c index 1782b41df095..5f3c2b42787f 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -397,11 +397,13 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, void __naked __kprobes kretprobe_trampoline(void) { __asm__ __volatile__ ( + "sub sp, sp, #16 \n\t" "stmdb sp!, {r0 - r11} \n\t" "mov r0, sp \n\t" "bl trampoline_handler \n\t" "mov lr, r0 \n\t" "ldmia sp!, {r0 - r11} \n\t" + "add sp, sp, #16 \n\t" #ifdef CONFIG_THUMB2_KERNEL "bx lr \n\t" #else From patchwork Wed May 26 08:03:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12280835 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 501FEC2B9F7 for ; Wed, 26 May 2021 08:03:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 298AB613D3 for ; Wed, 26 May 2021 08:03:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233236AbhEZIFS (ORCPT ); Wed, 26 May 2021 04:05:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:40472 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233182AbhEZIFS (ORCPT ); Wed, 26 May 2021 04:05:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 45E3F613B4; Wed, 26 May 2021 08:03:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622016227; bh=IjupCuH7LUBDawzWyZY7m3hIBhvkMzv28EFK3pFOSwg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cQr8s3XJkWkywOHXFJrqwkPjpIR3KYXk8arUIvGshrkE6iUkMaRoIvgUDVx95Y6L2 PNpvrhp4vYdRN81oPdGdqoYbC0iHXhO4lxy9UE87xWyjsrs1SC75Pa6VSDYmmunMDT jMstLLc/QoU9ahAoxfJXfF8Ju+Co2Au1b24eDErK0/vmgSUnnGN1evH6xeqqTJfmf+ msuYyhXyq3Ftj7SlI9QlF5s3feDYhnZxfiyWoWFY5/GUHTf0sKkBgRPoIhERfmF6ry pRKB7x2l50mD3QV7si/3VMvq3Bfw/kWdgXY3kNmSkmiwjt6js2os9OorJjTgo4t5FU FmUhV9O5mdO7A== From: Masami Hiramatsu To: Steven Rostedt , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com, Josh Poimboeuf , linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: [PATCH -tip v6 09/13] kprobes: Setup instruction pointer in __kretprobe_trampoline_handler Date: Wed, 26 May 2021 17:03:41 +0900 Message-Id: <162201622111.278331.11505326612383898085.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162201612941.278331.5293566981784464165.stgit@devnote2> References: <162201612941.278331.5293566981784464165.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org To simplify the stacktrace with pt_regs from kretprobe handler, set the correct return address to the instruction pointer in the pt_regs before calling kretprobe handlers. Suggested-by: Josh Poimboeuf Signed-off-by: Masami Hiramatsu --- Changes in v3: - Cast the correct_ret_addr to unsigned long. --- kernel/kprobes.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 54e5b89aad67..1598aca375c9 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1914,6 +1914,9 @@ unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, BUG_ON(1); } + /* Set the instruction pointer to the correct address */ + instruction_pointer_set(regs, (unsigned long)correct_ret_addr); + /* Run them. */ first = current->kretprobe_instances.first; while (first) { From patchwork Wed May 26 08:03:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12280837 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 71845C2B9F7 for ; Wed, 26 May 2021 08:04:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 572956143E for ; Wed, 26 May 2021 08:04:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232743AbhEZIF3 (ORCPT ); Wed, 26 May 2021 04:05:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:40646 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232614AbhEZIF3 (ORCPT ); Wed, 26 May 2021 04:05:29 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C9617613D3; Wed, 26 May 2021 08:03:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622016238; bh=YoSuzmD4HYDIR1nxiMTmGqdnaU88RgVp1FEKUAPIIT8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oYlicS6/iDFBAvmAn9Gu2xJRK7jrGs/rm+lWraQ9PdELYQVhTKlZBjdSFfqnbp01T i1LrrGfaiQ/syIXYrfZixfBFDUfqpsVr9QTsjAhQsjNQnBDnpUvxCq0PgPBGU4JfhC dGkn8yv+9ZGXsvSao/4UwzyhvZiAMNi/JnmIyiUQjXT4QtYMXO10DfJU656KC0Q8Lu y9jo6luKCRV+R3BgYS4xqn+Wtn1qeaDdKwMl8P7KTR067n4JU8DbO6IB1Ng+DZB5Kr tDBaKBczqsb8k/o5KaWffh6hZe1HSA9BeCzbIoG9WJ+tCGf9NmVxml8WIzvtqfaU65 N7va3YPUqeYYQ== From: Masami Hiramatsu To: Steven Rostedt , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com, Josh Poimboeuf , linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: [PATCH -tip v6 10/13] x86/kprobes: Push a fake return address at kretprobe_trampoline Date: Wed, 26 May 2021 17:03:52 +0900 Message-Id: <162201623241.278331.4061034283741994264.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162201612941.278331.5293566981784464165.stgit@devnote2> References: <162201612941.278331.5293566981784464165.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org This changes x86/kretprobe stack frame on kretprobe_trampoline a bit, which now push the kretprobe_trampoline as a fake return address at the bottom of the stack frame. With this fix, the ORC unwinder will see the kretprobe_trampoline as a return address. Signed-off-by: Masami Hiramatsu Suggested-by: Josh Poimboeuf --- arch/x86/kernel/kprobes/core.c | 31 ++++++++++++++++++++++--------- 1 file changed, 22 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 9a6763fd066e..4f3567a9974f 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1041,28 +1041,31 @@ asm( ".global kretprobe_trampoline\n" ".type kretprobe_trampoline, @function\n" "kretprobe_trampoline:\n" - /* We don't bother saving the ss register */ #ifdef CONFIG_X86_64 - " pushq %rsp\n" + /* Push fake return address to tell the unwinder it's a kretprobe */ + " pushq $kretprobe_trampoline\n" UNWIND_HINT_FUNC + /* Save the sp-8, this will be fixed later */ + " pushq %rsp\n" " pushfq\n" SAVE_REGS_STRING " movq %rsp, %rdi\n" " call trampoline_handler\n" - /* Replace saved sp with true return address. */ - " movq %rax, 19*8(%rsp)\n" RESTORE_REGS_STRING + " addq $8, %rsp\n" " popfq\n" #else - " pushl %esp\n" + /* Push fake return address to tell the unwinder it's a kretprobe */ + " pushl $kretprobe_trampoline\n" UNWIND_HINT_FUNC + /* Save the sp-4, this will be fixed later */ + " pushl %esp\n" " pushfl\n" SAVE_REGS_STRING " movl %esp, %eax\n" " call trampoline_handler\n" - /* Replace saved sp with true return address. */ - " movl %eax, 15*4(%esp)\n" RESTORE_REGS_STRING + " addl $4, %esp\n" " popfl\n" #endif " ret\n" @@ -1073,8 +1076,10 @@ NOKPROBE_SYMBOL(kretprobe_trampoline); /* * Called from kretprobe_trampoline */ -__used __visible void *trampoline_handler(struct pt_regs *regs) +__used __visible void trampoline_handler(struct pt_regs *regs) { + unsigned long *frame_pointer; + /* fixup registers */ regs->cs = __KERNEL_CS; #ifdef CONFIG_X86_32 @@ -1082,8 +1087,16 @@ __used __visible void *trampoline_handler(struct pt_regs *regs) #endif regs->ip = (unsigned long)&kretprobe_trampoline; regs->orig_ax = ~0UL; + regs->sp += sizeof(long); + frame_pointer = ((unsigned long *)®s->sp) + 1; - return (void *)kretprobe_trampoline_handler(regs, ®s->sp); + /* Replace fake return address with real one. */ + *frame_pointer = kretprobe_trampoline_handler(regs, frame_pointer); + /* + * Move flags to sp so that kretprobe_trapmoline can return + * right after popf. + */ + regs->sp = regs->flags; } NOKPROBE_SYMBOL(trampoline_handler); From patchwork Wed May 26 08:04:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12280839 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 0C6C6C2B9F7 for ; Wed, 26 May 2021 08:04:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6D3C613E6 for ; Wed, 26 May 2021 08:04:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232763AbhEZIFk (ORCPT ); Wed, 26 May 2021 04:05:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:40794 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232614AbhEZIFk (ORCPT ); Wed, 26 May 2021 04:05:40 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AD8B4613B4; Wed, 26 May 2021 08:04:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622016249; bh=JRj98AwQ1oExN3PtE2Kd1LBWPt7ablXsd9kQQcSUitU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R+x1tHA2XcoK/u5IXFZ/f+9m+Ad3o3tjLolbvxh+HU4BZ9E4Yzq1eoZ0yCtHwCCF2 IcTQLKEyrmwWO8EzFniMeYBT7rRiw7E0i3eoav/rwQ8CGkW/cq1Lc5USWheA6wXU4h XqFYM+Hr+bTXCSH1Ph+BXU/yYGg2wzRGXwih3hJKW5xPFIPXVkGTyotY9pewxlIVgi wi5H6pY7NkzAhmdLy3n1baUz3DxVWmvh9jYLk34MgSDN1eMNXwS+ml4Wu4TQt9bqqY g1tZTPp0TP2UqT+VONmYA6zl7mpyH1sJ+Rm+9vuzS5F+J0DsXmi+5Gus7S7M5M32Pg iRQbmAopdauPQ== From: Masami Hiramatsu To: Steven Rostedt , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com, Josh Poimboeuf , linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: [PATCH -tip v6 11/13] x86/unwind: Recover kretprobe trampoline entry Date: Wed, 26 May 2021 17:04:03 +0900 Message-Id: <162201624347.278331.4677822345434037169.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162201612941.278331.5293566981784464165.stgit@devnote2> References: <162201612941.278331.5293566981784464165.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Since the kretprobe replaces the function return address with the kretprobe_trampoline on the stack, x86 unwinders can not continue the stack unwinding at that point, or record kretprobe_trampoline instead of correct return address. To fix this issue, find the correct return address from task's kretprobe_instances as like as function-graph tracer does. With this fix, the unwinder can correctly unwind the stack from kretprobe event on x86, as below. <...>-135 [003] ...1 6.722338: r_full_proxy_read_0: (vfs_read+0xab/0x1a0 <- full_proxy_read) <...>-135 [003] ...1 6.722377: => kretprobe_trace_func+0x209/0x2f0 => kretprobe_dispatcher+0x4a/0x70 => __kretprobe_trampoline_handler+0xca/0x150 => trampoline_handler+0x44/0x70 => kretprobe_trampoline+0x2a/0x50 => vfs_read+0xab/0x1a0 => ksys_read+0x5f/0xe0 => do_syscall_64+0x33/0x40 => entry_SYSCALL_64_after_hwframe+0x44/0xae Reported-by: Daniel Xu Signed-off-by: Masami Hiramatsu Suggested-by: Josh Poimboeuf --- Changes in v5: - Fix the case of interrupt happens on kretprobe_trampoline+0. Changes in v3: - Split out the kretprobe side patch - Fix build error when CONFIG_KRETPROBES=n. Changes in v2: - Remove kretprobe wrapper functions from unwind_orc.c - Do not fixup state->ip when unwinding with regs because kretprobe fixup instruction pointer before calling handler. --- arch/x86/include/asm/unwind.h | 23 +++++++++++++++++++++++ arch/x86/kernel/unwind_frame.c | 4 ++-- arch/x86/kernel/unwind_guess.c | 3 +-- arch/x86/kernel/unwind_orc.c | 19 +++++++++++++++---- 4 files changed, 41 insertions(+), 8 deletions(-) diff --git a/arch/x86/include/asm/unwind.h b/arch/x86/include/asm/unwind.h index 70fc159ebe69..36d3971c0a2c 100644 --- a/arch/x86/include/asm/unwind.h +++ b/arch/x86/include/asm/unwind.h @@ -4,6 +4,7 @@ #include #include +#include #include #include @@ -15,6 +16,7 @@ struct unwind_state { unsigned long stack_mask; struct task_struct *task; int graph_idx; + struct llist_node *kr_cur; bool error; #if defined(CONFIG_UNWINDER_ORC) bool signal, full_regs; @@ -99,6 +101,27 @@ void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size, void *orc, size_t orc_size) {} #endif +static inline +unsigned long unwind_recover_kretprobe(struct unwind_state *state, + unsigned long addr, unsigned long *addr_p) +{ + return is_kretprobe_trampoline(addr) ? + kretprobe_find_ret_addr(state->task, addr_p, &state->kr_cur) : + addr; +} + +/* Recover the return address modified by instrumentation (e.g. kretprobe) */ +static inline +unsigned long unwind_recover_ret_addr(struct unwind_state *state, + unsigned long addr, unsigned long *addr_p) +{ + unsigned long ret; + + ret = ftrace_graph_ret_addr(state->task, &state->graph_idx, + addr, addr_p); + return unwind_recover_kretprobe(state, ret, addr_p); +} + /* * This disables KASAN checking when reading a value from another task's stack, * since the other task could be running on another CPU and could have poisoned diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c index d7c44b257f7f..24e33b44b2be 100644 --- a/arch/x86/kernel/unwind_frame.c +++ b/arch/x86/kernel/unwind_frame.c @@ -3,6 +3,7 @@ #include #include #include +#include #include #include #include @@ -240,8 +241,7 @@ static bool update_stack_state(struct unwind_state *state, else { addr_p = unwind_get_return_address_ptr(state); addr = READ_ONCE_TASK_STACK(state->task, *addr_p); - state->ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, - addr, addr_p); + state->ip = unwind_recover_ret_addr(state, addr, addr_p); } /* Save the original stack pointer for unwind_dump(): */ diff --git a/arch/x86/kernel/unwind_guess.c b/arch/x86/kernel/unwind_guess.c index c49f10ffd8cd..884d68a6e714 100644 --- a/arch/x86/kernel/unwind_guess.c +++ b/arch/x86/kernel/unwind_guess.c @@ -15,8 +15,7 @@ unsigned long unwind_get_return_address(struct unwind_state *state) addr = READ_ONCE_NOCHECK(*state->sp); - return ftrace_graph_ret_addr(state->task, &state->graph_idx, - addr, state->sp); + return unwind_recover_ret_addr(state, addr, state->sp); } EXPORT_SYMBOL_GPL(unwind_get_return_address); diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index a1202536fc57..c70dfeea4552 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -2,6 +2,7 @@ #include #include #include +#include #include #include #include @@ -534,9 +535,8 @@ bool unwind_next_frame(struct unwind_state *state) if (!deref_stack_reg(state, ip_p, &state->ip)) goto err; - state->ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, - state->ip, (void *)ip_p); - + state->ip = unwind_recover_ret_addr(state, state->ip, + (unsigned long *)ip_p); state->sp = sp; state->regs = NULL; state->prev_regs = NULL; @@ -549,7 +549,15 @@ bool unwind_next_frame(struct unwind_state *state) (void *)orig_ip); goto err; } - + /* + * There is a small chance to interrupt at the entry of + * kretprobe_trampoline where the ORC info doesn't exist. + * That point is right after the RET to kretprobe_trampoline + * which was modified return address. So the @addr_p must + * be right before the regs->sp. + */ + state->ip = unwind_recover_kretprobe(state, state->ip, + (unsigned long *)(state->sp - sizeof(long))); state->regs = (struct pt_regs *)sp; state->prev_regs = NULL; state->full_regs = true; @@ -562,6 +570,9 @@ bool unwind_next_frame(struct unwind_state *state) (void *)orig_ip); goto err; } + /* See UNWIND_HINT_TYPE_REGS case comment. */ + state->ip = unwind_recover_kretprobe(state, state->ip, + (unsigned long *)(state->sp - sizeof(long))); if (state->full_regs) state->prev_regs = state->regs; From patchwork Wed May 26 08:04:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12280841 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 E81CFC2B9F7 for ; Wed, 26 May 2021 08:04:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C4FC96143C for ; Wed, 26 May 2021 08:04:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233270AbhEZIFu (ORCPT ); Wed, 26 May 2021 04:05:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:40948 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232873AbhEZIFu (ORCPT ); Wed, 26 May 2021 04:05:50 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1FE0E613E6; Wed, 26 May 2021 08:04:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622016259; bh=3iDqN6IbfHW8PfeoC8K9td24ZOufoTiVRxV3XEeWOhk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QwNmlrAEsmm+PPrntKATZVPVpsEnSHSWy+NV6ZvjoWZ72i4bwJZnxHh/57RbPxjQW oDhtYPFIqA+Cr18GCU7FV5qSFkVL57Uy4WuZ6Ts0Fn524PY9wRlj/GeXAJFMW8juI2 xnkGZ7pFiULrOSsSKrknMXxuHRKcntveqiWDVQqm3Y0/hptWd/esu/WvZ1dKL0DIHE ZQZ/IRPBvTX+PJBl5hlcLxU3TK6JGxU9cJPwn+hJfa637je2yjsXRT4uWCRXy39apP kqrTEdHMSXe39qdROvbLD9jQh8dSkNH0VWBUSPu2vcV6fPZfqcrQnzDtxwolXQxGIi jz4RRVDIvi7Xw== From: Masami Hiramatsu To: Steven Rostedt , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com, Josh Poimboeuf , linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: [PATCH -tip v6 12/13] tracing: Show kretprobe unknown indicator only for kretprobe_trampoline Date: Wed, 26 May 2021 17:04:14 +0900 Message-Id: <162201625426.278331.16464105461089821909.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162201612941.278331.5293566981784464165.stgit@devnote2> References: <162201612941.278331.5293566981784464165.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org ftrace shows "[unknown/kretprobe'd]" indicator all addresses in the kretprobe_trampoline, but the modified address by kretprobe should be only kretprobe_trampoline+0. Signed-off-by: Masami Hiramatsu Acked-by: Steven Rostedt (VMware) --- kernel/trace/trace_output.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-) diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index d0368a569bfa..e46780670742 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include @@ -346,22 +347,12 @@ int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...) } EXPORT_SYMBOL_GPL(trace_output_call); -#ifdef CONFIG_KRETPROBES -static inline const char *kretprobed(const char *name) +static inline const char *kretprobed(const char *name, unsigned long addr) { - static const char tramp_name[] = "kretprobe_trampoline"; - int size = sizeof(tramp_name); - - if (strncmp(tramp_name, name, size) == 0) + if (is_kretprobe_trampoline(addr)) return "[unknown/kretprobe'd]"; return name; } -#else -static inline const char *kretprobed(const char *name) -{ - return name; -} -#endif /* CONFIG_KRETPROBES */ void trace_seq_print_sym(struct trace_seq *s, unsigned long address, bool offset) @@ -374,7 +365,7 @@ trace_seq_print_sym(struct trace_seq *s, unsigned long address, bool offset) sprint_symbol(str, address); else kallsyms_lookup(address, NULL, NULL, NULL, str); - name = kretprobed(str); + name = kretprobed(str, address); if (name && strlen(name)) { trace_seq_puts(s, name); From patchwork Wed May 26 08:04:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12280843 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 11A4EC47088 for ; Wed, 26 May 2021 08:04:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E474C6143C for ; Wed, 26 May 2021 08:04:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232841AbhEZIGB (ORCPT ); Wed, 26 May 2021 04:06:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:41108 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233238AbhEZIGA (ORCPT ); Wed, 26 May 2021 04:06:00 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B26BD613B4; Wed, 26 May 2021 08:04:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622016269; bh=zHgGf+J9R2KJWdm0E1kc2aXiEeqSmAci5E8/Yg36PtQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KqdukoZpB3011YdRVNndQ6gJoV2vFJYfZ7gl92y1r060VFkXPolIMqX183z4HKkB7 VXRxarHbIcViaEGcKmKTzhtrmFrOOTvaN3ZM3XB/QTYqOHMURQYTxUIK7xSALytgSD TDGDZXRhOeDcV6nNP2+HZBfoTunt7GsTDq6kHIx0sCCZ2QONbTpaJAWKpTqwDRvuj9 2gmz6vI05eYzCMJBA0DxLe92a9IT3JpBipLUNu+S6feI00v7zeL4OrTmAPeEZI3n3V 2tF7jO/UzhIo0tzpbU2gyFR67Nd5m/52ALb81X4CQRHk39hPZzDs6cxq7mWeg7jn6b uHfT+x7NapRSw== From: Masami Hiramatsu To: Steven Rostedt , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com, Josh Poimboeuf , linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: [PATCH -tip v6 13/13] x86/kprobes: Fixup return address in generic trampoline handler Date: Wed, 26 May 2021 17:04:25 +0900 Message-Id: <162201626487.278331.9722092310737938059.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162201612941.278331.5293566981784464165.stgit@devnote2> References: <162201612941.278331.5293566981784464165.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org In x86, kretprobe trampoline address on the stack frame will be replaced with the real return address after returning from trampoline_handler. Before fixing the return address, the real return address can be found in the current->kretprobe_instances. However, since there is a window between updating the current->kretprobe_instances and fixing the address on the stack, if an interrupt caused at that timing and the interrupt handler does stacktrace, it may fail to unwind because it can not get the correct return address from current->kretprobe_instances. This will minimize that window by fixing the return address right before updating current->kretprobe_instances. Signed-off-by: Masami Hiramatsu --- arch/x86/kernel/kprobes/core.c | 15 +++++++++++++-- kernel/kprobes.c | 8 ++++++++ 2 files changed, 21 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 4f3567a9974f..3dec85ca5d9e 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1032,6 +1032,7 @@ STACK_FRAME_NON_STANDARD(kretprobe_trampoline); #undef UNWIND_HINT_FUNC #define UNWIND_HINT_FUNC #endif + /* * When a retprobed function returns, this code saves registers and * calls trampoline_handler() runs, which calls the kretprobe's handler. @@ -1073,6 +1074,17 @@ asm( ); NOKPROBE_SYMBOL(kretprobe_trampoline); +void arch_kretprobe_fixup_return(struct pt_regs *regs, + unsigned long correct_ret_addr) +{ + unsigned long *frame_pointer; + + frame_pointer = ((unsigned long *)®s->sp) + 1; + + /* Replace fake return address with real one. */ + *frame_pointer = correct_ret_addr; +} + /* * Called from kretprobe_trampoline */ @@ -1090,8 +1102,7 @@ __used __visible void trampoline_handler(struct pt_regs *regs) regs->sp += sizeof(long); frame_pointer = ((unsigned long *)®s->sp) + 1; - /* Replace fake return address with real one. */ - *frame_pointer = kretprobe_trampoline_handler(regs, frame_pointer); + kretprobe_trampoline_handler(regs, frame_pointer); /* * Move flags to sp so that kretprobe_trapmoline can return * right after popf. diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 1598aca375c9..d5869664bb61 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1899,6 +1899,12 @@ unsigned long kretprobe_find_ret_addr(struct task_struct *tsk, void *fp, } NOKPROBE_SYMBOL(kretprobe_find_ret_addr); +void __weak arch_kretprobe_fixup_return(struct pt_regs *regs, + unsigned long correct_ret_addr) +{ + /* Do nothing by default. */ +} + unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, void *frame_pointer) { @@ -1940,6 +1946,8 @@ unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, first = first->next; } + arch_kretprobe_fixup_return(regs, (unsigned long)correct_ret_addr); + /* Unlink all nodes for this frame. */ first = current->kretprobe_instances.first; current->kretprobe_instances.first = node->next;