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 524B8C433F5 for ; Fri, 22 Oct 2021 20:50:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3C0AE610A1 for ; Fri, 22 Oct 2021 20:50:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234664AbhJVUwh (ORCPT ); Fri, 22 Oct 2021 16:52:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:40574 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234442AbhJVUvE (ORCPT ); Fri, 22 Oct 2021 16:51:04 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D7F7A613B5; Fri, 22 Oct 2021 20:48:45 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.95) (envelope-from ) id 1me1T2-000QVp-Vq; Fri, 22 Oct 2021 16:48:44 -0400 Message-ID: <20211022204844.821961287@goodmis.org> User-Agent: quilt/0.66 Date: Fri, 22 Oct 2021 16:48:32 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Masami Hiramatsu , Will Deacon Subject: [for-next][PATCH 36/40] arm64: kprobes: Make a frame pointer on __kretprobe_trampoline References: <20211022204756.099054287@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Masami Hiramatsu 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 Acked-by: Will Deacon Signed-off-by: Steven Rostedt (VMware) --- 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 -- 2.33.0