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 36863C433F5 for ; Wed, 13 Oct 2021 10:04:29 +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 EABF26101D for ; Wed, 13 Oct 2021 10:04:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org EABF26101D 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:In-Reply-To:MIME-Version:References: 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=P3vxzzEuMn4M+febEWJ0RrYkJxhSD8d0pMJsEEMbqqQ=; b=Wnk5ecAwJlO9xC kAny5lUBnBrVQool/YzHnqAGN0MlvafqOLITY6Hzg7rH6xOaAL/OUsn2FY9m35GmPoGIRvWQkqTGa H2MH4+B8lo3l5HsbmoD43odBTY+WkFJtmZ4X7MBCHjVfMVlC0LkbgQXNUqLPQpeYSUl/DnAi6gp6R 9ZBtzIHzRSm24l9Sf3mHdicpZ5j4LGSq6LPKCv2wMaPBvUyv21tvkBDhbQLB1ZSW58vaqLwpcliOA fBcmOt4oWg+ZF7DKPAKFgKuQQtx8borrhHRol0ExUf7cEtrEf0fxYRvsiMGAcp3O3MBr5jqBl63LW mNTcyS7epRyMLa8kWp/w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mab4n-00FsZ7-Ug; Wed, 13 Oct 2021 10:01:35 +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 1maZP4-00FWSK-8I for linux-arm-kernel@lists.infradead.org; Wed, 13 Oct 2021 08:14:23 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id E316860FDA; Wed, 13 Oct 2021 08:14:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1634112861; bh=NykAuL4Zs+K1r0m5ec470r276RbfqkZyRxE5hp85tts=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YDJuvWzO9Q9VVshMROzj0M+J3PvfMSu2V4Hj8rvk2A9SEnSRwGQQ0i7Ai54KcpYtZ TKZVNl9ExEhZUZ5lfMGfVCLhn36epSWvd+oYvYY21GY/N6kEPaOmhs1x6CIXh3aRks x+ipkpeNICeDerkzU3iAcnrQ0M+tWN7Nj/JCzyF1s1A0ByUPmqFaHPjaFF+sWuwnnW Y3CB7VIttO78gYaUbRRxdAW4zBIPeYPgAWse/pk67jNEHGFQyxnq5cqRNs6mzHUBi9 G/Cgf2BD8KHKoJyKJB9LC3JA7Osp7adEErhC3ufinnGfjLopagms8bsyej3iSqoo82 t3HZR+tIBOv0Q== Date: Wed, 13 Oct 2021 09:14:16 +0100 From: Will Deacon To: Masami Hiramatsu 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: <20211013081416.GC6701@willie-the-truck> References: <163369609308.636038.15295764725220907794.stgit@devnote2> <163369613866.636038.15240679956943005288.stgit@devnote2> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <163369613866.636038.15240679956943005288.stgit@devnote2> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211013_011422_388763_0EEACC9F X-CRM114-Status: GOOD ( 22.57 ) 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 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. If it's only relevant for kprobes, then let's define it conditionally too (based on CONFIG_KRETPROBES ?) > 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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel