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 AEC1EC433FE for ; Wed, 13 Oct 2021 08:14:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9257D61040 for ; Wed, 13 Oct 2021 08:14:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238846AbhJMIRA (ORCPT ); Wed, 13 Oct 2021 04:17:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:51658 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238871AbhJMIQy (ORCPT ); Wed, 13 Oct 2021 04:16:54 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AD54460FDA; Wed, 13 Oct 2021 08:14:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1634112890; bh=Kr5n30jWJFn/1ztvhvCbSOta4kJ1v2lin+xuRMC2dz4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lQUEFZWpunPpDLyiyf/ScamsM3tBj/uky2XgVcM3Vq7YyWv78uyBjg5kOYg8BdZ7L 2C1shLcdXbmwns55oM0aA5MqrZvlOAJCaWzahBY5MFMl24l8ovnERcZ136C+eJMgUZ PQSHwmo5iMqFzmVDXHtJu95xzyYdxNTwSRm+wy5Cx9i7DdVVmSpWeqA/UDo9v4WdcF DUnfm2MvvVJk1wb6me+KBz3LXYQRJh2IRVgRE7bw8MMHQP9MbwFHuvC0tfYOAQRHLc 1y4V4mqC+CeFOIcY8rFuET5U/ufRaToQH7h7s0W3jG/5r1qv51uPAA2+W88x+2lC0C JH5DxEHEFvsGw== Date: Wed, 13 Oct 2021 09:14:45 +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 3/8] arm64: kprobes: Record frame pointer with kretprobe instance Message-ID: <20211013081445.GD6701@willie-the-truck> References: <163369609308.636038.15295764725220907794.stgit@devnote2> <163369611948.636038.11552166777773804729.stgit@devnote2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <163369611948.636038.11552166777773804729.stgit@devnote2> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 08, 2021 at 09:28:39PM +0900, Masami Hiramatsu wrote: > Record the frame pointer instead of stack address with kretprobe > instance as the identifier on the instance list. > Since arm64 always enable CONFIG_FRAME_POINTER, we can use the > actual frame pointer (x29). > > Signed-off-by: Masami Hiramatsu > --- > arch/arm64/kernel/probes/kprobes.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c > index e7ad6da980e8..d9dfa82c1f18 100644 > --- a/arch/arm64/kernel/probes/kprobes.c > +++ b/arch/arm64/kernel/probes/kprobes.c > @@ -401,14 +401,14 @@ int __init arch_populate_kprobe_blacklist(void) > > void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs) > { > - return (void *)kretprobe_trampoline_handler(regs, (void *)kernel_stack_pointer(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 = (kprobe_opcode_t *)regs->regs[30]; > - ri->fp = (void *)kernel_stack_pointer(regs); > + ri->fp = (void *)regs->regs[29]; > > /* replace return addr (x30) with trampoline */ > regs->regs[30] = (long)&__kretprobe_trampoline; Acked-by: Will Deacon Will