From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7C25C433F5 for ; Thu, 14 Oct 2021 08:05:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BC691610F9 for ; Thu, 14 Oct 2021 08:05:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230090AbhJNIIC (ORCPT ); Thu, 14 Oct 2021 04:08:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:59494 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229970AbhJNIIA (ORCPT ); Thu, 14 Oct 2021 04:08:00 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C49296109F; Thu, 14 Oct 2021 08:05:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1634198755; bh=c4DPsOBWeX76u4ENO2ueRzg9rUgiQezuGLMSVcxGPjs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=cfNWlrbUDak7Dq22RabDrI3MAL6NjwABc0iVTwGOZWvSS9ka+EalgLze5R4NOUuTX CNHCfrI4b99IpX2yiC/JurFRHMwd4nag9++4zdJFuuV/8Kp01eemuegcdiEGif4G8l dezAGzfzXL+NXUGdkHwri7CyaU4kNFFyYTIM2xSf5l5jfpH1AXvwZ9cTKzQKhcwO4s Xg8c4NoXw6bJtdODROaaC0oLaIwwLnfOWAqhJVMLwNTp+N/djcyKmi4G9JzBll26d7 W2Uz7shBrdFnfwbcQGqiZqP/DxC7zGOLxuhDmLV0zsonuvxY2O2Z8J18wJvvHKI+e4 oITbPMyKrfkLA== Date: Thu, 14 Oct 2021 17:05:52 +0900 From: Masami Hiramatsu To: Will Deacon Cc: Steven Rostedt , "Naveen N . Rao" , Ananth N Mavinakayanahalli , Ingo Molnar , linux-kernel@vger.kernel.org, Sven Schnelle , Catalin Marinas , Russell King , Nathan Chancellor , Nick Desaulniers , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 5/8] arm64: Recover kretprobe modified return address in stacktrace Message-Id: <20211014170552.a588e29947e1cd63cdf0c5b5@kernel.org> In-Reply-To: <20211013081416.GC6701@willie-the-truck> References: <163369609308.636038.15295764725220907794.stgit@devnote2> <163369613866.636038.15240679956943005288.stgit@devnote2> <20211013081416.GC6701@willie-the-truck> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 13 Oct 2021 09:14:16 +0100 Will Deacon wrote: > On Fri, Oct 08, 2021 at 09:28:58PM +0900, Masami Hiramatsu wrote: > > Since the kretprobe replaces the function return address with > > the kretprobe_trampoline on the stack, stack unwinder shows it > > instead of the correct return address. > > > > This checks whether the next return address is the > > __kretprobe_trampoline(), and if so, try to find the correct > > return address from the kretprobe instance list. > > > > With this fix, now arm64 can enable > > CONFIG_ARCH_CORRECT_STACKTRACE_ON_KRETPROBE, and pass the > > kprobe self tests. > > > > Signed-off-by: Masami Hiramatsu > > --- > > arch/arm64/Kconfig | 1 + > > arch/arm64/include/asm/stacktrace.h | 2 ++ > > arch/arm64/kernel/stacktrace.c | 3 +++ > > 3 files changed, 6 insertions(+) > > > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > > index 5c7ae4c3954b..edde5171ffb2 100644 > > --- a/arch/arm64/Kconfig > > +++ b/arch/arm64/Kconfig > > @@ -11,6 +11,7 @@ config ARM64 > > select ACPI_PPTT if ACPI > > select ARCH_HAS_DEBUG_WX > > select ARCH_BINFMT_ELF_STATE > > + select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE > > select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION > > select ARCH_ENABLE_MEMORY_HOTPLUG > > select ARCH_ENABLE_MEMORY_HOTREMOVE > > diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h > > index 8aebc00c1718..8f997a602651 100644 > > --- a/arch/arm64/include/asm/stacktrace.h > > +++ b/arch/arm64/include/asm/stacktrace.h > > @@ -9,6 +9,7 @@ > > #include > > #include > > #include > > +#include > > > > #include > > #include > > @@ -59,6 +60,7 @@ struct stackframe { > > #ifdef CONFIG_FUNCTION_GRAPH_TRACER > > int graph; > > #endif > > + struct llist_node *kr_cur; > > }; > > Please update the comment above this structure to describe the new member > you're adding. OK, let me update that. > If it's only relevant for kprobes, then let's define it > conditionally too (based on CONFIG_KRETPROBES ?) Ah, good point! Yes, it must be only valid when CONFIG_KRETPROBES=y. Thank you, > > > extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame); > > diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c > > index 8982a2b78acf..f1eef5745542 100644 > > --- a/arch/arm64/kernel/stacktrace.c > > +++ b/arch/arm64/kernel/stacktrace.c > > @@ -129,6 +129,8 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) > > frame->pc = ret_stack->ret; > > } > > #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ > > + if (is_kretprobe_trampoline(frame->pc)) > > + frame->pc = kretprobe_find_ret_addr(tsk, (void *)frame->fp, &frame->kr_cur); > > > > frame->pc = ptrauth_strip_insn_pac(frame->pc); > > > > @@ -224,6 +226,7 @@ noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry, > > { > > struct stackframe frame; > > > > + memset(&frame, 0, sizeof(frame)); > > Why do we need this? > > Will -- Masami Hiramatsu From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D784C433FE for ; Thu, 14 Oct 2021 08:08:28 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F11DE6109F for ; Thu, 14 Oct 2021 08:08:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org F11DE6109F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Mime-Version:References:In-Reply-To: Message-Id:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=5DPBN5hjCZ/lV8+ZvQyofqOOSZoLMf/61tVIkIt66Uw=; b=zZF/a4SdlhMdGK RVF+/PqKCS7fBqxp9CcgpolcCgko0u6KTIwGlrEfaqIU9SsWFaAsOjrYsh48jbdL6cq6qEZyRGTqg jioy59jEmnRdk7lgk4icNz6+vJl6Is6uETkUVlg6BOuF4gp04pkPaAIJn26qhTgRFL989orQeyfb2 1C8+YRuNqw4hGsWHjrlGrXSBkLGkQe5pX+oUL+xgakyX/L6Ly/twC+agi2sSbiMNXmBbLtppX9AyM O/kzKn2KFu4lvedOSQjDVI2AdTRBlHRvs3f3f/X7CuF0GGpJL6Cst06roNVvRiRuqBT4XoTSSDhI9 YB3QJXPROWg5Lw+Z3edg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mavkZ-0025Ge-7l; Thu, 14 Oct 2021 08:06:03 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mavkR-0025F4-NZ for linux-arm-kernel@lists.infradead.org; Thu, 14 Oct 2021 08:05:57 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id C49296109F; Thu, 14 Oct 2021 08:05:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1634198755; bh=c4DPsOBWeX76u4ENO2ueRzg9rUgiQezuGLMSVcxGPjs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=cfNWlrbUDak7Dq22RabDrI3MAL6NjwABc0iVTwGOZWvSS9ka+EalgLze5R4NOUuTX CNHCfrI4b99IpX2yiC/JurFRHMwd4nag9++4zdJFuuV/8Kp01eemuegcdiEGif4G8l dezAGzfzXL+NXUGdkHwri7CyaU4kNFFyYTIM2xSf5l5jfpH1AXvwZ9cTKzQKhcwO4s Xg8c4NoXw6bJtdODROaaC0oLaIwwLnfOWAqhJVMLwNTp+N/djcyKmi4G9JzBll26d7 W2Uz7shBrdFnfwbcQGqiZqP/DxC7zGOLxuhDmLV0zsonuvxY2O2Z8J18wJvvHKI+e4 oITbPMyKrfkLA== Date: Thu, 14 Oct 2021 17:05:52 +0900 From: Masami Hiramatsu To: Will Deacon Cc: Steven Rostedt , "Naveen N . Rao" , Ananth N Mavinakayanahalli , Ingo Molnar , linux-kernel@vger.kernel.org, Sven Schnelle , Catalin Marinas , Russell King , Nathan Chancellor , Nick Desaulniers , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 5/8] arm64: Recover kretprobe modified return address in stacktrace Message-Id: <20211014170552.a588e29947e1cd63cdf0c5b5@kernel.org> In-Reply-To: <20211013081416.GC6701@willie-the-truck> References: <163369609308.636038.15295764725220907794.stgit@devnote2> <163369613866.636038.15240679956943005288.stgit@devnote2> <20211013081416.GC6701@willie-the-truck> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211014_010555_857845_D226E4DB X-CRM114-Status: GOOD ( 28.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, 13 Oct 2021 09:14:16 +0100 Will Deacon wrote: > On Fri, Oct 08, 2021 at 09:28:58PM +0900, Masami Hiramatsu wrote: > > Since the kretprobe replaces the function return address with > > the kretprobe_trampoline on the stack, stack unwinder shows it > > instead of the correct return address. > > > > This checks whether the next return address is the > > __kretprobe_trampoline(), and if so, try to find the correct > > return address from the kretprobe instance list. > > > > With this fix, now arm64 can enable > > CONFIG_ARCH_CORRECT_STACKTRACE_ON_KRETPROBE, and pass the > > kprobe self tests. > > > > Signed-off-by: Masami Hiramatsu > > --- > > arch/arm64/Kconfig | 1 + > > arch/arm64/include/asm/stacktrace.h | 2 ++ > > arch/arm64/kernel/stacktrace.c | 3 +++ > > 3 files changed, 6 insertions(+) > > > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > > index 5c7ae4c3954b..edde5171ffb2 100644 > > --- a/arch/arm64/Kconfig > > +++ b/arch/arm64/Kconfig > > @@ -11,6 +11,7 @@ config ARM64 > > select ACPI_PPTT if ACPI > > select ARCH_HAS_DEBUG_WX > > select ARCH_BINFMT_ELF_STATE > > + select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE > > select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION > > select ARCH_ENABLE_MEMORY_HOTPLUG > > select ARCH_ENABLE_MEMORY_HOTREMOVE > > diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h > > index 8aebc00c1718..8f997a602651 100644 > > --- a/arch/arm64/include/asm/stacktrace.h > > +++ b/arch/arm64/include/asm/stacktrace.h > > @@ -9,6 +9,7 @@ > > #include > > #include > > #include > > +#include > > > > #include > > #include > > @@ -59,6 +60,7 @@ struct stackframe { > > #ifdef CONFIG_FUNCTION_GRAPH_TRACER > > int graph; > > #endif > > + struct llist_node *kr_cur; > > }; > > Please update the comment above this structure to describe the new member > you're adding. OK, let me update that. > If it's only relevant for kprobes, then let's define it > conditionally too (based on CONFIG_KRETPROBES ?) Ah, good point! Yes, it must be only valid when CONFIG_KRETPROBES=y. Thank you, > > > extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame); > > diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c > > index 8982a2b78acf..f1eef5745542 100644 > > --- a/arch/arm64/kernel/stacktrace.c > > +++ b/arch/arm64/kernel/stacktrace.c > > @@ -129,6 +129,8 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) > > frame->pc = ret_stack->ret; > > } > > #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ > > + if (is_kretprobe_trampoline(frame->pc)) > > + frame->pc = kretprobe_find_ret_addr(tsk, (void *)frame->fp, &frame->kr_cur); > > > > frame->pc = ptrauth_strip_insn_pac(frame->pc); > > > > @@ -224,6 +226,7 @@ noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry, > > { > > struct stackframe frame; > > > > + memset(&frame, 0, sizeof(frame)); > > Why do we need this? > > Will -- Masami Hiramatsu _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel