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 X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68353C43381 for ; Mon, 18 Mar 2019 07:59:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 31C532085A for ; Mon, 18 Mar 2019 07:59:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552895948; bh=673SMqkAlXA8cblGV2cyAlD79kgMIFkPnnhL+OUh9L8=; h=From:To:Cc:Subject:Date:List-ID:From; b=Z4sYgR36VgNAz7A+saSTxA8WClAYdM9cyzgadK8WtZA1wvnoG0ItGZwnOaaEIkPMC HG65oaI6ei7vD6MVROXbNuU/Ax9yCd4VFuWVKKcgZXEYeQsIvCk+mcj6Uuj9ZUvkDK SqFaP3LiQlre6roFpLxv8x1ZrxSmykKgdyXfC7pk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726704AbfCRH7G (ORCPT ); Mon, 18 Mar 2019 03:59:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:57650 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726291AbfCRH7G (ORCPT ); Mon, 18 Mar 2019 03:59:06 -0400 Received: from localhost.localdomain (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8669B20835; Mon, 18 Mar 2019 07:59:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552895945; bh=673SMqkAlXA8cblGV2cyAlD79kgMIFkPnnhL+OUh9L8=; h=From:To:Cc:Subject:Date:From; b=lsBGQbEDhW3pXZVrhWEEE2thxVdaCWqiX1o+Eno5RlYa/YPmlTf9gVIDDH0dWi3D+ U3rBHsNjm/hpFoYA8PNjfZlBNRrXwbwa2eBIPnY1uO0gq71TowJw/MqRPq16fSCRpn w/424whUBcCviOPpYxVDUi3AGNEcAzIIOrktCP5c= From: Masami Hiramatsu To: Catalin Marinas , Will Deacon Cc: Steven Rostedt , mhiramat@kernel.org, Oleg Nesterov , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH] arm64: ptrace: Add function argument access API Date: Mon, 18 Mar 2019 16:59:02 +0900 Message-Id: <155289594227.10570.1879705446198840331.stgit@devnote2> X-Mailer: git-send-email 2.17.1 User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add regs_get_argument() which returns N th argument of the function call. On arm64, it supports up to 8th argument. Note that this chooses most probably assignment, in some case it can be incorrect (e.g. passing data structure or floating point etc.) This enables ftrace kprobe events to access kernel function arguments via $argN syntax. Signed-off-by: Masami Hiramatsu --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/ptrace.h | 18 ++++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 117b2541ef3d..6ba0da4be73c 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -148,6 +148,7 @@ config ARM64 select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP select HAVE_REGS_AND_STACK_ACCESS_API + select HAVE_FUNCTION_ARG_ACCESS_API select HAVE_RCU_TABLE_FREE select HAVE_RCU_TABLE_INVALIDATE select HAVE_RSEQ diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h index ec60174c8c18..cfa1bc9b8b70 100644 --- a/arch/arm64/include/asm/ptrace.h +++ b/arch/arm64/include/asm/ptrace.h @@ -305,6 +305,24 @@ static inline unsigned long regs_return_value(struct pt_regs *regs) return regs->regs[0]; } +/** + * regs_get_kernel_argument() - get Nth function argument in kernel + * @regs: pt_regs of that context + * @n: function argument number (start from 0) + * + * regs_get_argument() returns @n th argument of the function call. + * Note that this chooses most probably assignment, in some case + * it can be incorrect. + */ +static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs, + unsigned int n) +{ +#define NR_REG_ARGUMENTS 8 + if (n < NR_REG_ARGUMENTS) + return regs_get_register(regs, n << 3); + return 0; +} + /* We must avoid circular header include via sched.h */ struct task_struct; int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task);