From patchwork Sun Jul 11 13:35:10 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: 12369131 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=-19.7 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 CA58EC07E96 for ; Sun, 11 Jul 2021 13:35:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ADC296121E for ; Sun, 11 Jul 2021 13:35:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232889AbhGKNiB (ORCPT ); Sun, 11 Jul 2021 09:38:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:48560 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232793AbhGKNiB (ORCPT ); Sun, 11 Jul 2021 09:38:01 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 265A361205; Sun, 11 Jul 2021 13:35:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626010514; bh=a1OJt7X0UIwdJpIZLUO/oAUQE9sxWcUM+Qc4V/S2Mjs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jiWMvKjX24JV+LmhMy91S802EBtmsJqmogMlDOfUF7zhEisfouDR954zkpg7pg0p8 x7CNmRruJYNZebzCPYcdzOrmBBaPSow1q+qyLvxzdVKmdl1Tj7n8nyYTxHinVVWVPC uhZfk1QpKOCNswPjmJNcxasYizBC6OAbWALHndl3fZPm1VdGrv4oBjp5JvdRTBxvsX eJQY24zyn7kGd6epb9BRh1BmxEjLDyNsrF4KBQLwW6VYPFMOFwt+O+IxeykLNdoKOI WHml02NJDToTvb8gquIkuAORrRMIZvwkpfBktbLSXq1MvmPoJWLRw+TTVxbtYmfDxN Dl9xT9FwPUeeA== From: Masami Hiramatsu To: Steven Rostedt , Josh Poimboeuf , 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, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: [PATCH -tip v9 03/14] kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler() Date: Sun, 11 Jul 2021 22:35:10 +0900 Message-Id: <162601051063.1318837.8773002693937324222.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <162601048053.1318837.1550594515476777588.stgit@devnote2> References: <162601048053.1318837.1550594515476777588.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org The __kretprobe_trampoline_handler() callback, called from low level arch kprobes methods, has the 'trampoline_address' parameter, which is entirely superfluous as it basically just replicates: dereference_kernel_function_descriptor(kretprobe_trampoline) In fact we had bugs in arch code where it wasn't replicated correctly. So remove this superfluous parameter and use kretprobe_trampoline_addr() instead. Signed-off-by: Masami Hiramatsu Tested-by: Andrii Nakryiko --- Changes in v9: - Update changelog according to Ingo's suggestion. Changes in v8: - Use dereference_kernel_function_descriptor() to get the kretprobe_trampoline address. 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 5f0415fc7328..3cee75c87f97 100644 --- a/arch/arc/kernel/kprobes.c +++ b/arch/arc/kernel/kprobes.c @@ -381,7 +381,7 @@ 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 a59e38de4a03..08098ed6f035 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -392,8 +392,7 @@ 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 ce429cbacd35..f627a12984a8 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -401,8 +401,7 @@ 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 e823c3051b24..bf1e6c7094fc 100644 --- a/arch/csky/kernel/probes/kprobes.c +++ b/arch/csky/kernel/probes/kprobes.c @@ -387,7 +387,7 @@ 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 0f8573bbf520..44c84c20b626 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 b0934a0d7aed..b33bd2498651 100644 --- a/arch/mips/kernel/kprobes.c +++ b/arch/mips/kernel/kprobes.c @@ -485,8 +485,7 @@ 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 077ab73e6e56..0764e8a0de69 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -416,7 +416,7 @@ 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 dcf7c1f6d136..26a47870a237 100644 --- a/arch/riscv/kernel/probes/kprobes.c +++ b/arch/riscv/kernel/probes/kprobes.c @@ -369,7 +369,7 @@ 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 9bca57fe6b6a..71d86922dd51 100644 --- a/arch/s390/kernel/kprobes.c +++ b/arch/s390/kernel/kprobes.c @@ -348,7 +348,7 @@ 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 1c7f358ef0be..8e76a35e6e33 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 4c05a4ee6a0e..401534236c2e 100644 --- a/arch/sparc/kernel/kprobes.c +++ b/arch/sparc/kernel/kprobes.c @@ -451,7 +451,7 @@ 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 b6e046e4b289..0c59ef5971de 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1064,7 +1064,7 @@ __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 c9e0c13db84a..31cb9a929ac3 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -188,15 +188,23 @@ 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_kernel_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; /* @@ -205,7 +213,7 @@ 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 2540cd56fa81..f9a075374522 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1869,7 +1869,6 @@ 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; @@ -1884,7 +1883,7 @@ 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