From nobody Fri Jun 19 09:39:52 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B2667C433EF for ; Wed, 6 Apr 2022 00:21:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1584418AbiDEX6Q (ORCPT ); Tue, 5 Apr 2022 19:58:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37666 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348399AbiDEJrh (ORCPT ); Tue, 5 Apr 2022 05:47:37 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9BDD76E57B; Tue, 5 Apr 2022 02:33:54 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1D5D4616D2; Tue, 5 Apr 2022 09:33:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E16F6C385A6; Tue, 5 Apr 2022 09:33:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649151233; bh=68gbc2AXKSN3tRLzHyhrzyqpSc4gZP8dxeQpKcf9ezA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pZcXmZ+AWPl+uE14MwKlMpmmcsKfi3t1I3TnC+TGAc4agrmtaPtWcGP6znqejd017 07Blju+cSqrhL4+m/2HwlI4Y+fS+YLVm8booS5rdL3RhK85mLr2vf2AScdCmCw0Z6m MDVvanNn0UbMNZpzKG99fYRC1Vd5Oddmv2dzjpmGkbTGPO5Mtd1P/XfvUgKSo+Aht7 KM5g6wH57uvRB93250SuWzyDBpAhSGZBUd2yTm/+ZsXQVdxVi14TQBhoc4PsJbJiX9 oMi0Xibos6mNUXNdrzd5Dj1CZxDA0qTvGetZgD6hNUH1f91L8z8bUrIIJjNnTIQaEE 1ybOAVUFVjtQg== From: Masami Hiramatsu To: Alexei Starovoitov , Alexei Starovoitov Cc: Daniel Borkmann , Shubham Bansal , Andrii Nakryiko , Masami Hiramatsu , bpf@vger.kernel.org, kernel-team@fb.com, Jiri Olsa , Steven Rostedt , "Naveen N . Rao" , Anil S Keshavamurthy , "David S . Miller" , linux-kernel@vger.kernel.org, Mark Rutland , Will Deacon , Ard Biesheuvel , Russell King , Catalin Marinas , linux-arm-kernel@lists.infradead.org Subject: [PATCH bpf 1/4] ARM: unwind: Initialize the lr_addr field of unwind_ctrl_block Date: Tue, 5 Apr 2022 18:33:47 +0900 Message-Id: <164915122721.982637.1510683757540074397.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <164915121498.982637.12787715964983738566.stgit@devnote2> References: <164915121498.982637.12787715964983738566.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since the unwind_ctrl_block::lr_addr is finally passed to stackframe::lr_addr, that value will be exposed unconditionally. Thus it should be initialized. Without this fix, when unwind_frame() doesn't update the unwind_ctrl_block::lr_addr (e.g. 'lr' register is not saved in the target function), stackframe::lr_addr will contain a wrong value. Signed-off-by: Masami Hiramatsu Reported-by: kernel test robot --- arch/arm/kernel/unwind.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c index a37ea6c772cd..93e767682cf4 100644 --- a/arch/arm/kernel/unwind.c +++ b/arch/arm/kernel/unwind.c @@ -404,6 +404,7 @@ int unwind_frame(struct stackframe *frame) ctrl.vrs[SP] =3D frame->sp; ctrl.vrs[LR] =3D frame->lr; ctrl.vrs[PC] =3D 0; + ctrl.lr_addr =3D 0; =20 if (idx->insn =3D=3D 1) /* can't unwind */ From nobody Fri Jun 19 09:39:52 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD600C3527B for ; Tue, 5 Apr 2022 21:37:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1380881AbiDEVha (ORCPT ); Tue, 5 Apr 2022 17:37:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43898 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348521AbiDEJrz (ORCPT ); Tue, 5 Apr 2022 05:47:55 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 989289FDD; Tue, 5 Apr 2022 02:34:06 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1CBBC616D9; Tue, 5 Apr 2022 09:34:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8A706C385A2; Tue, 5 Apr 2022 09:34:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649151245; bh=qU7NQO8a/GNTqpF3kK+hxQlG2bDuw47+HzlGrFENsk0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N77R/4na/+s2mEBMETZddTv/xM3MLgIvIy050lDk/AhaphAO0eWTunjvlgZm8fOC5 WebyxBQ0r8tyIFtxrMKghV1OhO94uWoZBfWAszOOMesbTJsGUYZk2N903xLDSL2F+G d4OasRXoX+XHMKSEhhymIalNknUyVRlGzbeHsuF42qJk/BAwfOkzEqtujJHKSQAzFF J71kaKMXg2UmOZ4Bw+dCL+31g+eun6BLFnKlFJ431SgXt10/xUNmUhCRwTArerMb42 cohDMpn2/Tq2lFdFpK0oNIu6gecLy7WrptY3JZ0C0btnVz3EtBtUK8BrJxAHddNF1w stIFOb9r3nlFQ== From: Masami Hiramatsu To: Alexei Starovoitov , Alexei Starovoitov Cc: Daniel Borkmann , Shubham Bansal , Andrii Nakryiko , Masami Hiramatsu , bpf@vger.kernel.org, kernel-team@fb.com, Jiri Olsa , Steven Rostedt , "Naveen N . Rao" , Anil S Keshavamurthy , "David S . Miller" , linux-kernel@vger.kernel.org, Mark Rutland , Will Deacon , Ard Biesheuvel , Russell King , Catalin Marinas , linux-arm-kernel@lists.infradead.org Subject: [PATCH bpf 2/4] rethook,fprobe,kprobes: Check a failure in the rethook_hook() Date: Tue, 5 Apr 2022 18:33:59 +0900 Message-Id: <164915123885.982637.5653959785968470135.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <164915121498.982637.12787715964983738566.stgit@devnote2> References: <164915121498.982637.12787715964983738566.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since there are possible to fail to hook the function return (depends on archtecutre implememtation), rethook_hook() should return the error in that case and caller must check it. Signed-off-by: Masami Hiramatsu --- arch/x86/kernel/rethook.c | 4 +++- include/linux/rethook.h | 4 ++-- kernel/kprobes.c | 8 +++++--- kernel/trace/fprobe.c | 5 ++++- kernel/trace/rethook.c | 12 ++++++++++-- 5 files changed, 24 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/rethook.c b/arch/x86/kernel/rethook.c index 8a1c0111ae79..c92b4875e3b9 100644 --- a/arch/x86/kernel/rethook.c +++ b/arch/x86/kernel/rethook.c @@ -114,7 +114,7 @@ void arch_rethook_fixup_return(struct pt_regs *regs, } NOKPROBE_SYMBOL(arch_rethook_fixup_return); =20 -void arch_rethook_prepare(struct rethook_node *rh, struct pt_regs *regs, b= ool mcount) +int arch_rethook_prepare(struct rethook_node *rh, struct pt_regs *regs, bo= ol mcount) { unsigned long *stack =3D (unsigned long *)regs->sp; =20 @@ -123,5 +123,7 @@ void arch_rethook_prepare(struct rethook_node *rh, stru= ct pt_regs *regs, bool mc =20 /* Replace the return addr with trampoline addr */ stack[0] =3D (unsigned long) arch_rethook_trampoline; + + return 0; } NOKPROBE_SYMBOL(arch_rethook_prepare); diff --git a/include/linux/rethook.h b/include/linux/rethook.h index c8ac1e5afcd1..07b9c6663b8e 100644 --- a/include/linux/rethook.h +++ b/include/linux/rethook.h @@ -63,12 +63,12 @@ void rethook_free(struct rethook *rh); void rethook_add_node(struct rethook *rh, struct rethook_node *node); struct rethook_node *rethook_try_get(struct rethook *rh); void rethook_recycle(struct rethook_node *node); -void rethook_hook(struct rethook_node *node, struct pt_regs *regs, bool mc= ount); +int rethook_hook(struct rethook_node *node, struct pt_regs *regs, bool mco= unt); unsigned long rethook_find_ret_addr(struct task_struct *tsk, unsigned long= frame, struct llist_node **cur); =20 /* Arch dependent code must implement arch_* and trampoline code */ -void arch_rethook_prepare(struct rethook_node *node, struct pt_regs *regs,= bool mcount); +int arch_rethook_prepare(struct rethook_node *node, struct pt_regs *regs, = bool mcount); void arch_rethook_trampoline(void); =20 /** diff --git a/kernel/kprobes.c b/kernel/kprobes.c index dbe57df2e199..7fd7f1195bde 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2109,10 +2109,12 @@ static int pre_handler_kretprobe(struct kprobe *p, = struct pt_regs *regs) =20 ri =3D container_of(rhn, struct kretprobe_instance, node); =20 - if (rp->entry_handler && rp->entry_handler(ri, regs)) + if (rp->entry_handler && rp->entry_handler(ri, regs)) { rethook_recycle(rhn); - else - rethook_hook(rhn, regs, kprobe_ftrace(p)); + } else if (rethook_hook(rhn, regs, kprobe_ftrace(p)) < 0) { + rethook_recycle(rhn); + rp->nmissed++; + } =20 return 0; } diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index 89d9f994ebb0..d3b13294d545 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -48,7 +48,10 @@ static void fprobe_handler(unsigned long ip, unsigned lo= ng parent_ip, } fpr =3D container_of(rh, struct fprobe_rethook_node, node); fpr->entry_ip =3D ip; - rethook_hook(rh, ftrace_get_regs(fregs), true); + if (rethook_hook(rh, ftrace_get_regs(fregs), true) < 0) { + rethook_recycle(rh); + fp->nmissed++; + } } =20 out: diff --git a/kernel/trace/rethook.c b/kernel/trace/rethook.c index b56833700d23..e7db83438e45 100644 --- a/kernel/trace/rethook.c +++ b/kernel/trace/rethook.c @@ -174,11 +174,19 @@ NOKPROBE_SYMBOL(rethook_try_get); * from ftrace (mcount) callback, @mcount must be set true. If this is cal= led * from the real function entry (e.g. kprobes) @mcount must be set false. * This is because the way to hook the function return depends on the cont= ext. + * This returns 0 if succeeded to hook the function return, or -errno if + * failed. */ -void rethook_hook(struct rethook_node *node, struct pt_regs *regs, bool mc= ount) +int rethook_hook(struct rethook_node *node, struct pt_regs *regs, bool mco= unt) { - arch_rethook_prepare(node, regs, mcount); + int ret; + + ret =3D arch_rethook_prepare(node, regs, mcount); + if (ret < 0) + return ret; + __llist_add(&node->llist, ¤t->rethooks); + return 0; } NOKPROBE_SYMBOL(rethook_hook); From nobody Fri Jun 19 09:39:52 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38533C433EF for ; Tue, 5 Apr 2022 23:51:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1579378AbiDEXaj (ORCPT ); Tue, 5 Apr 2022 19:30:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39738 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348650AbiDEJsM (ORCPT ); Tue, 5 Apr 2022 05:48:12 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F2DE33EA6; Tue, 5 Apr 2022 02:34:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id C0EFFB81C98; Tue, 5 Apr 2022 09:34:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 14E90C385A3; Tue, 5 Apr 2022 09:34:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649151258; bh=BMCRwjjlfIbM/TUx+qbzoFbkQDj9Jg49pYE5HI9x5ZU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uKmOZ5seNEpToR8MuSNEsVJ2leBVvHeaapc2xV7SNxv4KPi3fIcR06QP9yqF3qoOu wmUB2Syw3RVtkF2RIMGIJR6QyLauTjLQg/CYdCmiaM204awVDb4DBZvpPmio0/bvba nK/rD7+Q3uqtjPA92XbJLw9LvStR7kq4AcBbPZVPOOUub1WIXFy1+JRKu3RFCETzH9 kuhsXadlRwohAXxVQVvWwEGUSrjMjxgz2SdnE7KJDZjpGsK1rhMned6Xl9q/Ut22E1 OGj+F2C6kN6erzo+jnlX3hu7MGTFViLK0UGeamv79v5f9IBsFuSM4tXX5B7w1YLEMF fUZVXgvVo9PjA== From: Masami Hiramatsu To: Alexei Starovoitov , Alexei Starovoitov Cc: Daniel Borkmann , Shubham Bansal , Andrii Nakryiko , Masami Hiramatsu , bpf@vger.kernel.org, kernel-team@fb.com, Jiri Olsa , Steven Rostedt , "Naveen N . Rao" , Anil S Keshavamurthy , "David S . Miller" , linux-kernel@vger.kernel.org, Mark Rutland , Will Deacon , Ard Biesheuvel , Russell King , Catalin Marinas , linux-arm-kernel@lists.infradead.org Subject: [PATCH bpf 3/4] ARM: rethook: Replace kretprobe trampoline with rethook Date: Tue, 5 Apr 2022 18:34:11 +0900 Message-Id: <164915125136.982637.15305442546225954227.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <164915121498.982637.12787715964983738566.stgit@devnote2> References: <164915121498.982637.12787715964983738566.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Replace the kretprob's trampoline code with the rethook on arm. This also enables rethook support on arm. Most of the code has been copied from kretprobe on arm. The significant difference is that the rethook on mcount (ftrace) support is added. If the rethook is called from the kprobes for kretprobe, there is no problem to replace the LR register with trampoline address because the LR register will be saved after kprobe probed. However, the mcount call will be placed right after making a stack frame for the function. This means we have to decode the stackframe to find where the LR register is saved. With the CONFIG_FRAME_POINTER, the frame pointer (FP register) is used. Without that, rethook has to unwind one stack frame to find it. Signed-off-by: Masami Hiramatsu --- arch/arm/Kconfig | 1=20 arch/arm/include/asm/stacktrace.h | 5 + arch/arm/kernel/stacktrace.c | 13 ++-- arch/arm/probes/Makefile | 1=20 arch/arm/probes/kprobes/core.c | 62 ------------------ arch/arm/probes/rethook.c | 127 +++++++++++++++++++++++++++++++++= ++++ 6 files changed, 139 insertions(+), 70 deletions(-) create mode 100644 arch/arm/probes/rethook.c diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index c1251856ef77..cb56c848930a 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -110,6 +110,7 @@ config ARM select HAVE_MOD_ARCH_SPECIFIC select HAVE_NMI select HAVE_OPTPROBES if !THUMB2_KERNEL + select HAVE_RETHOOK select HAVE_PERF_EVENTS select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP diff --git a/arch/arm/include/asm/stacktrace.h b/arch/arm/include/asm/stack= trace.h index 3e78f921b8b2..76a70b25863e 100644 --- a/arch/arm/include/asm/stacktrace.h +++ b/arch/arm/include/asm/stacktrace.h @@ -17,7 +17,8 @@ struct stackframe { =20 /* address of the LR value on the stack */ unsigned long *lr_addr; -#ifdef CONFIG_KRETPROBES + +#if defined(CONFIG_RETHOOK) struct llist_node *kr_cur; struct task_struct *tsk; #endif @@ -30,7 +31,7 @@ void arm_get_current_stackframe(struct pt_regs *regs, str= uct stackframe *frame) frame->sp =3D regs->ARM_sp; frame->lr =3D regs->ARM_lr; frame->pc =3D regs->ARM_pc; -#ifdef CONFIG_KRETPROBES +#if defined(CONFIG_RETHOOK) frame->kr_cur =3D NULL; frame->tsk =3D current; #endif diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c index b5efecb3d730..6df085ecdf41 100644 --- a/arch/arm/kernel/stacktrace.c +++ b/arch/arm/kernel/stacktrace.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0-only #include #include +#include #include #include #include @@ -66,10 +67,10 @@ int notrace unwind_frame(struct stackframe *frame) frame->sp =3D *(unsigned long *)(fp - 8); frame->pc =3D *(unsigned long *)(fp - 4); #endif -#ifdef CONFIG_KRETPROBES - if (is_kretprobe_trampoline(frame->pc)) - frame->pc =3D kretprobe_find_ret_addr(frame->tsk, - (void *)frame->fp, &frame->kr_cur); +#ifdef CONFIG_RETHOOK + if (is_rethook_trampoline(frame->pc)) + frame->pc =3D rethook_find_ret_addr(frame->tsk, frame->fp, + &frame->kr_cur); #endif =20 return 0; @@ -163,7 +164,7 @@ static noinline void __save_stack_trace(struct task_str= uct *tsk, here: frame.pc =3D (unsigned long)&&here; } -#ifdef CONFIG_KRETPROBES +#ifdef CONFIG_RETHOOK frame.kr_cur =3D NULL; frame.tsk =3D tsk; #endif @@ -184,7 +185,7 @@ void save_stack_trace_regs(struct pt_regs *regs, struct= stack_trace *trace) frame.sp =3D regs->ARM_sp; frame.lr =3D regs->ARM_lr; frame.pc =3D regs->ARM_pc; -#ifdef CONFIG_KRETPROBES +#ifdef CONFIG_RETHOOK frame.kr_cur =3D NULL; frame.tsk =3D current; #endif diff --git a/arch/arm/probes/Makefile b/arch/arm/probes/Makefile index 8b0ea5ace100..10c083a22223 100644 --- a/arch/arm/probes/Makefile +++ b/arch/arm/probes/Makefile @@ -6,3 +6,4 @@ obj-$(CONFIG_KPROBES) +=3D decode-thumb.o else obj-$(CONFIG_KPROBES) +=3D decode-arm.o endif +obj-$(CONFIG_RETHOOK) +=3D rethook.o diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c index 9090c3a74dcc..2f01f8267cc3 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -365,68 +365,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier= _block *self, return NOTIFY_DONE; } =20 -/* - * When a retprobed function returns, trampoline_handler() is called, - * calling the kretprobe's handler. We construct a struct pt_regs to - * give a view of registers r0-r11, sp, lr, and pc to the user - * return-handler. This is not a complete pt_regs structure, but that - * should be enough for stacktrace from the return handler with or - * without pt_regs. - */ -void __naked __kprobes __kretprobe_trampoline(void) -{ - __asm__ __volatile__ ( -#ifdef CONFIG_FRAME_POINTER - "ldr lr, =3D__kretprobe_trampoline \n\t" - /* __kretprobe_trampoline makes a framepointer on pt_regs. */ -#ifdef CONFIG_CC_IS_CLANG - "stmdb sp, {sp, lr, pc} \n\t" - "sub sp, sp, #12 \n\t" - /* In clang case, pt_regs->ip =3D lr. */ - "stmdb sp!, {r0 - r11, lr} \n\t" - /* fp points regs->r11 (fp) */ - "add fp, sp, #44 \n\t" -#else /* !CONFIG_CC_IS_CLANG */ - /* In gcc case, pt_regs->ip =3D fp. */ - "stmdb sp, {fp, sp, lr, pc} \n\t" - "sub sp, sp, #16 \n\t" - "stmdb sp!, {r0 - r11} \n\t" - /* fp points regs->r15 (pc) */ - "add fp, sp, #60 \n\t" -#endif /* CONFIG_CC_IS_CLANG */ -#else /* !CONFIG_FRAME_POINTER */ - "sub sp, sp, #16 \n\t" - "stmdb sp!, {r0 - r11} \n\t" -#endif /* CONFIG_FRAME_POINTER */ - "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 - "mov pc, lr \n\t" -#endif - : : : "memory"); -} - -/* Called from __kretprobe_trampoline */ -static __used __kprobes void *trampoline_handler(struct pt_regs *regs) -{ - return (void *)kretprobe_trampoline_handler(regs, (void *)regs->ARM_fp); -} - -void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, - struct pt_regs *regs) -{ - ri->ret_addr =3D (kprobe_opcode_t *)regs->ARM_lr; - ri->fp =3D (void *)regs->ARM_fp; - - /* Replace the return addr with trampoline addr. */ - regs->ARM_lr =3D (unsigned long)&__kretprobe_trampoline; -} - int __kprobes arch_trampoline_kprobe(struct kprobe *p) { return 0; diff --git a/arch/arm/probes/rethook.c b/arch/arm/probes/rethook.c new file mode 100644 index 000000000000..598a2b579b91 --- /dev/null +++ b/arch/arm/probes/rethook.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * arm implementation of rethook. Mostly copied from arch/arm/probes/kprob= es/core.c + */ + +#include +#include + +#include + +/* Called from arch_rethook_trampoline */ +static __used notrace unsigned long arch_rethook_trampoline_callback(struc= t pt_regs *regs) +{ + return rethook_trampoline_handler(regs, regs->ARM_fp); +} +NOKPROBE_SYMBOL(arch_rethook_trampoline_callback); + +/* + * When a rethook'ed function returns, it returns to arch_rethook_trampoli= ne + * which calls rethook callback. We construct a struct pt_regs to + * give a view of registers r0-r11, sp, lr, and pc to the user + * return-handler. This is not a complete pt_regs structure, but that + * should be enough for stacktrace from the return handler with or + * without pt_regs. + */ +asm( + ".text\n" + ".global arch_rethook_trampoline\n" + ".type arch_rethook_trampoline, %function\n" + "arch_rethook_trampoline:\n" +#ifdef CONFIG_FRAME_POINTER + "adr lr, . \n\t" + /* this makes a framepointer on pt_regs. */ +#ifdef CONFIG_CC_IS_CLANG + "stmdb sp, {sp, lr, pc} \n\t" + "sub sp, sp, #12 \n\t" + /* In clang case, pt_regs->ip =3D lr. */ + "stmdb sp!, {r0 - r11, lr} \n\t" + /* fp points regs->r11 (fp) */ + "add fp, sp, #44 \n\t" +#else /* !CONFIG_CC_IS_CLANG */ + /* In gcc case, pt_regs->ip =3D fp. */ + "stmdb sp, {fp, sp, lr, pc} \n\t" + "sub sp, sp, #16 \n\t" + "stmdb sp!, {r0 - r11} \n\t" + /* fp points regs->r15 (pc) */ + "add fp, sp, #60 \n\t" +#endif /* CONFIG_CC_IS_CLANG */ +#else /* !CONFIG_FRAME_POINTER */ + "sub sp, sp, #16 \n\t" + "stmdb sp!, {r0 - r11} \n\t" +#endif /* CONFIG_FRAME_POINTER */ + "mov r0, sp \n\t" + "bl arch_rethook_trampoline_callback \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 + "mov pc, lr \n\t" +#endif + ".size arch_rethook_trampoline, .-arch_rethook_trampoline\n" +); +NOKPROBE_SYMBOL(arch_rethook_trampoline); + +/* + * At the entry of function with mcount, if the FRAME_POINTER is enabled, + * the stack and registers are prepared for the mcount function as below. + * + * mov ip, sp + * push {fp, ip, lr, pc} + * sub fp, ip, #4 ; FP[0] =3D PC, FP[-4] =3D LR, and FP[-12] =3D call-= site FP. + * push {lr} + * bl <__gnu_mcount_nc> ; call ftrace + * + * And when returning from the function, call-site FP, SP and PC are resto= red + * from stack as below; + * + * ldm sp, {fp, sp, pc} + * + * Thus, if the arch_rethook_prepare() is called from real function entry, + * it must change the LR and save FP in pt_regs. But if it is called via + * mcount context (ftrace), it must change the LR on stack, which is next + * to the PC (=3D FP[-4]), and save the FP value at FP[-12]. + * + * If the FRAME_POINTER is disabled, we have to use arm unwinder to find w= here + * the LR is stored. + */ +int notrace arch_rethook_prepare(struct rethook_node *rh, struct pt_regs *= regs, bool mcount) +{ + unsigned long *lr_addr; + int ret; + + if (mcount) { + /* Clang + mcount case is not supported yet. */ + if (IS_ENABLED(CONFIG_CC_IS_CLANG)) + return -EOPNOTSUPP; + if (IS_ENABLED(CONFIG_FRAME_POINTER)) { + lr_addr =3D (unsigned long *)(regs->ARM_fp - 4); + rh->frame =3D *(unsigned long *)(regs->ARM_fp - 12); + } else { + struct stackframe frame; + + arm_get_current_stackframe(regs, &frame); + ret =3D unwind_frame(&frame); + if (ret < 0) + return -EINVAL; + + if (frame.lr_addr) + lr_addr =3D frame.lr_addr; + else + lr_addr =3D ®s->ARM_lr; + rh->frame =3D regs->ARM_fp; + } + } else { + lr_addr =3D ®s->ARM_lr; + rh->frame =3D regs->ARM_fp; + } + + /* Replace the return addr with trampoline addr. */ + rh->ret_addr =3D *lr_addr; + *lr_addr =3D (unsigned long)arch_rethook_trampoline; + + return 0; +} +NOKPROBE_SYMBOL(arch_rethook_prepare); From nobody Fri Jun 19 09:39:52 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4D602C433EF for ; Wed, 6 Apr 2022 00:51:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242985AbiDFAw2 (ORCPT ); Tue, 5 Apr 2022 20:52:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39718 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348731AbiDEJs3 (ORCPT ); Tue, 5 Apr 2022 05:48:29 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2D85403E5; Tue, 5 Apr 2022 02:34:33 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 76077B81CB3; Tue, 5 Apr 2022 09:34:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D98CBC385A2; Tue, 5 Apr 2022 09:34:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649151271; bh=LAFR0U8z2ATEUDfuQs2HtqiBTXOtY+cWH5gxvruL69g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=plKAaLGluFz/cApJ5yio6fQXV5HKiaqbxlApUKtouzQ0FddVpMqn5rdItfNfIjI4l jiV+MoMRw/hLMTT7WqP7gUmOHLWQ3W1O+LQUOppXA8eWujYNWhy05rSHwVc3PrgID1 DVNUfxN30EadxzQsttH5jdde6QvaFbqkjhMF4xXDPkOikhBRasYK2C+A+I7SeEzMmu BIFGVnokkmQRxNWY09Q/oOUsR0tzLE5D90IhRn+nXV/73mN2aBUpGtn2DpZjF8ZPjx akvK6RTgi6+xKMcJ5ba+BDX+qhsTUtJGFZmzP4xJvCcGNB6xFdfPHnuT3dd7S5DS0w SJsCqQBb/V4SQ== From: Masami Hiramatsu To: Alexei Starovoitov , Alexei Starovoitov Cc: Daniel Borkmann , Shubham Bansal , Andrii Nakryiko , Masami Hiramatsu , bpf@vger.kernel.org, kernel-team@fb.com, Jiri Olsa , Steven Rostedt , "Naveen N . Rao" , Anil S Keshavamurthy , "David S . Miller" , linux-kernel@vger.kernel.org, Mark Rutland , Will Deacon , Ard Biesheuvel , Russell King , Catalin Marinas , linux-arm-kernel@lists.infradead.org Subject: [PATCH bpf 4/4] arm64: rethook: Replace kretprobe trampoline with rethook Date: Tue, 5 Apr 2022 18:34:24 +0900 Message-Id: <164915126392.982637.10302202550404803304.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <164915121498.982637.12787715964983738566.stgit@devnote2> References: <164915121498.982637.12787715964983738566.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Replace the kretprobe's trampoline code with the rethook on arm64. The rethook on arm64 is almost renamed from kretprobe trampoline code. The mechanism is completely same. Signed-off-by: Masami Hiramatsu Reported-by: kernel test robot --- arch/arm64/Kconfig | 1=20 arch/arm64/include/asm/kprobes.h | 2 - arch/arm64/include/asm/stacktrace.h | 2 - arch/arm64/kernel/Makefile | 1=20 arch/arm64/kernel/probes/Makefile | 1=20 arch/arm64/kernel/probes/kprobes.c | 15 ---- arch/arm64/kernel/probes/kprobes_trampoline.S | 86 ---------------------= ---- arch/arm64/kernel/rethook.c | 26 +++++++ arch/arm64/kernel/rethook_trampoline.S | 87 +++++++++++++++++++++= ++++ arch/arm64/kernel/stacktrace.c | 9 +-- 10 files changed, 121 insertions(+), 109 deletions(-) delete mode 100644 arch/arm64/kernel/probes/kprobes_trampoline.S create mode 100644 arch/arm64/kernel/rethook.c create mode 100644 arch/arm64/kernel/rethook_trampoline.S diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 57c4c995965f..7d2945930283 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -204,6 +204,7 @@ config ARM64 select HAVE_SYSCALL_TRACEPOINTS select HAVE_KPROBES select HAVE_KRETPROBES + select HAVE_RETHOOK select HAVE_GENERIC_VDSO select IOMMU_DMA if IOMMU_SUPPORT select IRQ_DOMAIN diff --git a/arch/arm64/include/asm/kprobes.h b/arch/arm64/include/asm/kpro= bes.h index 05cd82eeca13..4ac558058377 100644 --- a/arch/arm64/include/asm/kprobes.h +++ b/arch/arm64/include/asm/kprobes.h @@ -39,8 +39,6 @@ void arch_remove_kprobe(struct kprobe *); int kprobe_fault_handler(struct pt_regs *regs, unsigned int fsr); int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data); -void __kretprobe_trampoline(void); -void __kprobes *trampoline_probe_handler(struct pt_regs *regs); =20 #endif /* CONFIG_KPROBES */ #endif /* _ARM_KPROBES_H */ diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/s= tacktrace.h index e77cdef9ca29..f781874f1609 100644 --- a/arch/arm64/include/asm/stacktrace.h +++ b/arch/arm64/include/asm/stacktrace.h @@ -58,7 +58,7 @@ struct stackframe { DECLARE_BITMAP(stacks_done, __NR_STACK_TYPES); unsigned long prev_fp; enum stack_type prev_type; -#ifdef CONFIG_KRETPROBES +#if defined(CONFIG_RETHOOK) struct llist_node *kr_cur; #endif }; diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 986837d7ec82..62e033b1b095 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -60,6 +60,7 @@ obj-$(CONFIG_ACPI_NUMA) +=3D acpi_numa.o obj-$(CONFIG_ARM64_ACPI_PARKING_PROTOCOL) +=3D acpi_parking_protocol.o obj-$(CONFIG_PARAVIRT) +=3D paravirt.o obj-$(CONFIG_RANDOMIZE_BASE) +=3D kaslr.o +obj-$(CONFIG_RETHOOK) +=3D rethook.o rethook_trampoline.o obj-$(CONFIG_HIBERNATION) +=3D hibernate.o hibernate-asm.o obj-$(CONFIG_ELF_CORE) +=3D elfcore.o obj-$(CONFIG_KEXEC_CORE) +=3D machine_kexec.o relocate_kernel.o \ diff --git a/arch/arm64/kernel/probes/Makefile b/arch/arm64/kernel/probes/M= akefile index 8e4be92e25b1..1fa58cda64ff 100644 --- a/arch/arm64/kernel/probes/Makefile +++ b/arch/arm64/kernel/probes/Makefile @@ -1,6 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_KPROBES) +=3D kprobes.o decode-insn.o \ - kprobes_trampoline.o \ simulate-insn.o obj-$(CONFIG_UPROBES) +=3D uprobes.o decode-insn.o \ simulate-insn.o diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/= kprobes.c index d9dfa82c1f18..4a3cc266e77e 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -399,21 +399,6 @@ int __init arch_populate_kprobe_blacklist(void) return ret; } =20 -void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs) -{ - return (void *)kretprobe_trampoline_handler(regs, (void *)regs->regs[29]); -} - -void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, - struct pt_regs *regs) -{ - ri->ret_addr =3D (kprobe_opcode_t *)regs->regs[30]; - ri->fp =3D (void *)regs->regs[29]; - - /* replace return addr (x30) with trampoline */ - regs->regs[30] =3D (long)&__kretprobe_trampoline; -} - int __kprobes arch_trampoline_kprobe(struct kprobe *p) { return 0; diff --git a/arch/arm64/kernel/probes/kprobes_trampoline.S b/arch/arm64/ker= nel/probes/kprobes_trampoline.S deleted file mode 100644 index 9a6499bed58b..000000000000 --- a/arch/arm64/kernel/probes/kprobes_trampoline.S +++ /dev/null @@ -1,86 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * trampoline entry and return code for kretprobes. - */ - -#include -#include -#include - - .text - - .macro save_all_base_regs - stp x0, x1, [sp, #S_X0] - stp x2, x3, [sp, #S_X2] - stp x4, x5, [sp, #S_X4] - stp x6, x7, [sp, #S_X6] - stp x8, x9, [sp, #S_X8] - stp x10, x11, [sp, #S_X10] - stp x12, x13, [sp, #S_X12] - stp x14, x15, [sp, #S_X14] - stp x16, x17, [sp, #S_X16] - stp x18, x19, [sp, #S_X18] - stp x20, x21, [sp, #S_X20] - stp x22, x23, [sp, #S_X22] - stp x24, x25, [sp, #S_X24] - stp x26, x27, [sp, #S_X26] - stp x28, x29, [sp, #S_X28] - add x0, sp, #PT_REGS_SIZE - stp lr, x0, [sp, #S_LR] - /* - * Construct a useful saved PSTATE - */ - mrs x0, nzcv - mrs x1, daif - orr x0, x0, x1 - mrs x1, CurrentEL - orr x0, x0, x1 - mrs x1, SPSel - orr x0, x0, x1 - stp xzr, x0, [sp, #S_PC] - .endm - - .macro restore_all_base_regs - ldr x0, [sp, #S_PSTATE] - and x0, x0, #(PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT) - msr nzcv, x0 - ldp x0, x1, [sp, #S_X0] - ldp x2, x3, [sp, #S_X2] - ldp x4, x5, [sp, #S_X4] - ldp x6, x7, [sp, #S_X6] - ldp x8, x9, [sp, #S_X8] - ldp x10, x11, [sp, #S_X10] - ldp x12, x13, [sp, #S_X12] - ldp x14, x15, [sp, #S_X14] - ldp x16, x17, [sp, #S_X16] - ldp x18, x19, [sp, #S_X18] - ldp x20, x21, [sp, #S_X20] - ldp x22, x23, [sp, #S_X22] - ldp x24, x25, [sp, #S_X24] - ldp x26, x27, [sp, #S_X26] - ldp x28, x29, [sp, #S_X28] - .endm - -SYM_CODE_START(__kretprobe_trampoline) - sub sp, sp, #PT_REGS_SIZE - - save_all_base_regs - - /* Setup a frame pointer. */ - add x29, sp, #S_FP - - mov x0, sp - bl trampoline_probe_handler - /* - * Replace trampoline address in lr with actual orig_ret_addr return - * address. - */ - mov lr, x0 - - /* The frame pointer (x29) is restored with other registers. */ - restore_all_base_regs - - add sp, sp, #PT_REGS_SIZE - ret - -SYM_CODE_END(__kretprobe_trampoline) diff --git a/arch/arm64/kernel/rethook.c b/arch/arm64/kernel/rethook.c new file mode 100644 index 000000000000..78bb6b968de5 --- /dev/null +++ b/arch/arm64/kernel/rethook.c @@ -0,0 +1,26 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Generic return hook for arm64. + * Most of the code is copied from arch/arm64/kernel/probes/kprobes.c + */ + +#include +#include + +/* This is called from arch_rethook_trampoline() */ +unsigned long __used arch_rethook_trampoline_callback(struct pt_regs *regs) +{ + return rethook_trampoline_handler(regs, regs->regs[29]); +} +NOKPROBE_SYMBOL(arch_rethook_trampoline_callback); + +int arch_rethook_prepare(struct rethook_node *rhn, struct pt_regs *regs, b= ool mcount) +{ + rhn->ret_addr =3D regs->regs[30]; + rhn->frame =3D regs->regs[29]; + + /* replace return addr (x30) with trampoline */ + regs->regs[30] =3D (u64)arch_rethook_trampoline; + return 0; +} +NOKPROBE_SYMBOL(arch_rethook_prepare); diff --git a/arch/arm64/kernel/rethook_trampoline.S b/arch/arm64/kernel/ret= hook_trampoline.S new file mode 100644 index 000000000000..146d4553674c --- /dev/null +++ b/arch/arm64/kernel/rethook_trampoline.S @@ -0,0 +1,87 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * trampoline entry and return code for rethook. + * Renamed from arch/arm64/kernel/probes/kprobes_trampoline.S + */ + +#include +#include +#include + + .text + + .macro save_all_base_regs + stp x0, x1, [sp, #S_X0] + stp x2, x3, [sp, #S_X2] + stp x4, x5, [sp, #S_X4] + stp x6, x7, [sp, #S_X6] + stp x8, x9, [sp, #S_X8] + stp x10, x11, [sp, #S_X10] + stp x12, x13, [sp, #S_X12] + stp x14, x15, [sp, #S_X14] + stp x16, x17, [sp, #S_X16] + stp x18, x19, [sp, #S_X18] + stp x20, x21, [sp, #S_X20] + stp x22, x23, [sp, #S_X22] + stp x24, x25, [sp, #S_X24] + stp x26, x27, [sp, #S_X26] + stp x28, x29, [sp, #S_X28] + add x0, sp, #PT_REGS_SIZE + stp lr, x0, [sp, #S_LR] + /* + * Construct a useful saved PSTATE + */ + mrs x0, nzcv + mrs x1, daif + orr x0, x0, x1 + mrs x1, CurrentEL + orr x0, x0, x1 + mrs x1, SPSel + orr x0, x0, x1 + stp xzr, x0, [sp, #S_PC] + .endm + + .macro restore_all_base_regs + ldr x0, [sp, #S_PSTATE] + and x0, x0, #(PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT) + msr nzcv, x0 + ldp x0, x1, [sp, #S_X0] + ldp x2, x3, [sp, #S_X2] + ldp x4, x5, [sp, #S_X4] + ldp x6, x7, [sp, #S_X6] + ldp x8, x9, [sp, #S_X8] + ldp x10, x11, [sp, #S_X10] + ldp x12, x13, [sp, #S_X12] + ldp x14, x15, [sp, #S_X14] + ldp x16, x17, [sp, #S_X16] + ldp x18, x19, [sp, #S_X18] + ldp x20, x21, [sp, #S_X20] + ldp x22, x23, [sp, #S_X22] + ldp x24, x25, [sp, #S_X24] + ldp x26, x27, [sp, #S_X26] + ldp x28, x29, [sp, #S_X28] + .endm + +SYM_CODE_START(arch_rethook_trampoline) + sub sp, sp, #PT_REGS_SIZE + + save_all_base_regs + + /* Setup a frame pointer. */ + add x29, sp, #S_FP + + mov x0, sp + bl arch_rethook_trampoline_callback + /* + * Replace trampoline address in lr with actual orig_ret_addr return + * address. + */ + mov lr, x0 + + /* The frame pointer (x29) is restored with other registers. */ + restore_all_base_regs + + add sp, sp, #PT_REGS_SIZE + ret + +SYM_CODE_END(arch_rethook_trampoline) diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index e4103e085681..5b717af4b555 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include #include @@ -38,7 +39,7 @@ static notrace void start_backtrace(struct stackframe *fr= ame, unsigned long fp, { frame->fp =3D fp; frame->pc =3D pc; -#ifdef CONFIG_KRETPROBES +#if defined(CONFIG_RETHOOK) frame->kr_cur =3D NULL; #endif =20 @@ -134,9 +135,9 @@ static int notrace unwind_frame(struct task_struct *tsk, frame->pc =3D orig_pc; } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ -#ifdef CONFIG_KRETPROBES - if (is_kretprobe_trampoline(frame->pc)) - frame->pc =3D kretprobe_find_ret_addr(tsk, (void *)frame->fp, &frame->kr= _cur); +#ifdef CONFIG_RETHOOK + if (is_rethook_trampoline(frame->pc)) + frame->pc =3D rethook_find_ret_addr(tsk, frame->fp, &frame->kr_cur); #endif =20 return 0;