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 C4AB1C433F5 for ; Wed, 13 Oct 2021 10:08:14 +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 8611361074 for ; Wed, 13 Oct 2021 10:08:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 8611361074 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=JmroklqOOZMWLuZKdxpSFmrLD8Nk1QQ+2ACpsvFobl4=; b=zSbPqBcmfkdkQA TOz3/ds2C2sNsfsIDzTbDFt0FSKtOC+wPLEBUz2wKzxVvtNVSrDRB3Xj/aPgPCkpNcPzT/DFmga7N P7lqfl1Mq7yuHu7zgQzDkN7PrLuUZFCHaTGn7OD3w0Xicb5qvawRLSsWJKfwVxKOV9zir1RE7n3ey Z1D0vdwTgyzv+zmm8csfjsjexfMAX6xz8Farm7oL27dT0izR2ZqGFPHU1iUcvdsSs+WiRcpBIQe5j EtKXsHewcWsK6iEBA6o6yMCiu5dOjaqkfW5MBt1L6ZRkUKi+TotaxNUQ/tMIvrg5YrX7PuaNdKgFd rThvgUifoB96BgXdSfIQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mab8S-00FtMO-Ki; Wed, 13 Oct 2021 10:05:22 +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 1maZPj-00FWe8-9Y for linux-arm-kernel@lists.infradead.org; Wed, 13 Oct 2021 08:15:04 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 52B8D603E5; Wed, 13 Oct 2021 08:15:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1634112902; bh=tkpjOjlIspU1fO21Mw4tWKGAWZohLqWteK7ZGUv5w5k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nuXhmlhp+E5VlaEvzFqNpqiLMdLY9oG6EwoYfmpY7Wtw/u1oKkQVnPPqeyQOGxrre Mxia2/m7W3IkjMbZuUCo+VbbdJKO3+cG5EZZ6qLoQ2sNGhuBm8t0RwR4USqqGYREYz GdyWlVnva078PLj3j4rq53BzCvjZRt4l6u/2H74MixYqZW1yml+FUuT6A5/+qaXCum l8WflP4odF3mcLe5kzDoAdzVHSnus/WI8vvdClmkyCHNYfpy5pfcoSsuy+6y0oip5V kPY1h9mjvMEiBVSu+qzrQVvcZHwkGuNmpPiRy+/Cc7OWZoKHJPM3O4ODKYUX7EkvDa SISh6rpQmbhtw== Date: Wed, 13 Oct 2021 09:14:57 +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 4/8] arm64: kprobes: Make a frame pointer on __kretprobe_trampoline Message-ID: <20211013081456.GE6701@willie-the-truck> References: <163369609308.636038.15295764725220907794.stgit@devnote2> <163369612899.636038.6691283708565501775.stgit@devnote2> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <163369612899.636038.6691283708565501775.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_011503_517828_F6FE021E X-CRM114-Status: GOOD ( 18.11 ) 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 09:28:49PM +0900, Masami Hiramatsu wrote: > Make a frame pointer (make the x29 register points the > address of pt_regs->regs[29]) on __kretprobe_trampoline. > > This frame pointer will be used by the stacktracer when it is > called from the kretprobe handlers. In this case, the stack > tracer will unwind stack to trampoline_probe_handler() and > find the next frame pointer in the stack frame of the > __kretprobe_trampoline(). > > Signed-off-by: Masami Hiramatsu > --- > arch/arm64/kernel/probes/kprobes_trampoline.S | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/arm64/kernel/probes/kprobes_trampoline.S b/arch/arm64/kernel/probes/kprobes_trampoline.S > index 520ee8711db1..9a6499bed58b 100644 > --- a/arch/arm64/kernel/probes/kprobes_trampoline.S > +++ b/arch/arm64/kernel/probes/kprobes_trampoline.S > @@ -66,6 +66,9 @@ SYM_CODE_START(__kretprobe_trampoline) > > save_all_base_regs > > + /* Setup a frame pointer. */ > + add x29, sp, #S_FP > + > mov x0, sp > bl trampoline_probe_handler > /* > @@ -74,6 +77,7 @@ SYM_CODE_START(__kretprobe_trampoline) > */ > mov lr, x0 > > + /* The frame pointer (x29) is restored with other registers. */ > restore_all_base_regs > > add sp, sp, #PT_REGS_SIZE Acked-by: Will Deacon Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel