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 B375EC433F5 for ; Fri, 8 Oct 2021 12:28:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9BEA160FD8 for ; Fri, 8 Oct 2021 12:28:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241672AbhJHMat (ORCPT ); Fri, 8 Oct 2021 08:30:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:60546 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241493AbhJHMas (ORCPT ); Fri, 8 Oct 2021 08:30:48 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6A36360FC2; Fri, 8 Oct 2021 12:28:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1633696133; bh=DDWSnIkSXXxhQSQVm1lvRkcHmdLh5M6ojrT3AbCWFpQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IS/u79LiqdIkNAN7MNKV0e/+ErXFmTq71qnLSzWDZoREx+dUFZoPTQYY0nxfmRuYQ yUUETSZs40NozRwPVpyzHMN1Aapbx9rv2Qo8e58ksM1KMRfixQ87w1ZaWCXCcUPtrD t4AUoVZMkUtiB/WwA5pgxKmf9lUPB6lcaDeUJH20GnSKeX5FvKE2eouWBTMN3xAuDM owncWUN/FSmJNBbFA0/rQEjoKU4oZapEXN+KL/J4P4n9iKNtn8E/JNad4mrpm5VvOv ISXvIiCT4aoPiJyS9rfhiXPXqG0zhDQVKG9B3RFL6QmvMV7ANAkPvSS5EvDbSzCWtA tpRa+x0ijMUaw== From: Masami Hiramatsu To: Steven Rostedt Cc: "Naveen N . Rao" , Ananth N Mavinakayanahalli , Ingo Molnar , linux-kernel@vger.kernel.org, mhiramat@kernel.org, Sven Schnelle , Catalin Marinas , Will Deacon , Russell King , Nathan Chancellor , Nick Desaulniers , linux-arm-kernel@lists.infradead.org Subject: [PATCH 4/8] arm64: kprobes: Make a frame pointer on __kretprobe_trampoline Date: Fri, 8 Oct 2021 21:28:49 +0900 Message-Id: <163369612899.636038.6691283708565501775.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163369609308.636038.15295764725220907794.stgit@devnote2> References: <163369609308.636038.15295764725220907794.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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