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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 9089BC43381 for ; Mon, 18 Mar 2019 10:49:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6BB2D20854 for ; Mon, 18 Mar 2019 10:49:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727628AbfCRKtp (ORCPT ); Mon, 18 Mar 2019 06:49:45 -0400 Received: from foss.arm.com ([217.140.101.70]:59690 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726449AbfCRKtm (ORCPT ); Mon, 18 Mar 2019 06:49:42 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id ED0F61682; Mon, 18 Mar 2019 03:49:41 -0700 (PDT) Received: from usa.arm.com (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 0100C3F614; Mon, 18 Mar 2019 03:49:38 -0700 (PDT) From: Sudeep Holla To: x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Cc: Sudeep Holla , Catalin Marinas , Will Deacon , Oleg Nesterov , Paul Mackerras , Michael Ellerman , Thomas Gleixner , Ingo Molnar , Richard Weinberger , jdike@addtoit.com, Steve Capper , Haibo Xu , Bin Lu , Andy Lutomirski Subject: [PATCH v2 2/6] ptrace: introduce ptrace_syscall_enter to consolidate PTRACE_SYSEMU handling Date: Mon, 18 Mar 2019 10:49:21 +0000 Message-Id: <20190318104925.16600-3-sudeep.holla@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190318104925.16600-1-sudeep.holla@arm.com> References: <20190318104925.16600-1-sudeep.holla@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently each architecture handles PTRACE_SYSEMU in very similar way. It's completely arch independent and can be handled in the code helping to consolidate PTRACE_SYSEMU handling. Let's introduce a hook 'ptrace_syscall_enter' that arch specific syscall entry code can call. Cc: Oleg Nesterov Signed-off-by: Sudeep Holla --- include/linux/ptrace.h | 1 + kernel/ptrace.c | 22 ++++++++++++++++++++++ 2 files changed, 23 insertions(+) diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index edb9b040c94c..e30f51e3363e 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -407,6 +407,7 @@ static inline void user_single_step_report(struct pt_regs *regs) #define current_user_stack_pointer() user_stack_pointer(current_pt_regs()) #endif +extern long ptrace_syscall_enter(struct pt_regs *regs); extern int task_current_syscall(struct task_struct *target, long *callno, unsigned long args[6], unsigned int maxargs, unsigned long *sp, unsigned long *pc); diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 4fa3b7f4c3c7..c9c505c483df 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -29,6 +29,7 @@ #include #include #include +#include /* * Access another process' address space via ptrace. @@ -557,6 +558,27 @@ static int ptrace_detach(struct task_struct *child, unsigned int data) return 0; } +/* + * Hook to check and report for PTRACE_SYSEMU, can be called from arch + * arch syscall entry code + */ +long ptrace_syscall_enter(struct pt_regs *regs) +{ +#ifdef TIF_SYSCALL_EMU + if (test_thread_flag(TIF_SYSCALL_EMU)) { + if (tracehook_report_syscall_entry(regs)) + /* + * We can ignore the return code here as we need + * return -1 always for syscall emulation irrespective + * of whether the tracehook report fails or succeed. + */ + ; + return -1L; + } +#endif + return 0; +} + /* * Detach all tasks we were using ptrace on. Called with tasklist held * for writing. -- 2.17.1