From patchwork Mon Mar 18 10:49:21 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep Holla X-Patchwork-Id: 160483 Delivered-To: patch@linaro.org Received: by 2002:a02:5cc1:0:0:0:0:0 with SMTP id w62csp2500424jad; Mon, 18 Mar 2019 03:49:46 -0700 (PDT) X-Google-Smtp-Source: APXvYqx7uj94G6XOaCfYwAgKrNUKewHeNMO8LP2qnUTmIfcXvu+ewyIVQgfKtqE01LaFKzvsbbfM X-Received: by 2002:a63:6a48:: with SMTP id f69mr16788674pgc.7.1552906186501; Mon, 18 Mar 2019 03:49:46 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1552906186; cv=none; d=google.com; s=arc-20160816; b=vOp2UTMWmej3CbptjA46zTAJUJagJF5UZSJFv3QWl/781Kizf9iJz5E14sRJx0MFxA 5cKM/EeVLxxfXWim/dqkKsdiq6En+3NplTNHQmFDmiOwIV0JOU+v2MBOtBJLIsyMrnNZ 6yRXkhhojIMKo44VlabBbJwHLI95Ze2G4STMEt7sKE4gvb59iMDTLOvhTeyfYjq+Y2vl Pmr/s7hCboHXISNM75Y4I21Po2oqdjHueqtjZJzoTeN31oUUmZStO6EN34v4fjNMf3Kv 1Me31fYzTmTcDJx75ToAPyzyFSz3EB1bLVagAYH84KZM8nje1uTtRJgTOwScGwGFztml CaRA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from; bh=lWV+rzRtCnrkOhn8PcNi/vTXVJVA5ub7g75UFyjaHy4=; b=DIXreZnUB274krkrFCzcPn0JJk1luuPa8v+NrffEQj01vS1dyjpC1FCx4iyEMpq3lu FUg3kJGVnkD0oK6E57YhxfjI5Qlf2zIFE5r+CBBq1WfsKOkobtyBBQwXT9LNVBI79AM6 o3C5rOITV8qG99pY5VjcyP3wdILGFuayNG0dP+gDFGAWCSZFwRLFSEhYlQ6OyPpgQK0t zd+sYkcrlDpEnq+RofDs6+P4k+f61WGKw+PmwJIgpZpxFKn1i9P3+uUwULr87MQDXKcP a+iMkaa1udaW4BLwgIgk6hlqdxdilpfp9Np37HnPRCcbH/cI/gGcJb9fiV2ARzM20zmw 1B9Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id n66si9295314pfb.62.2019.03.18.03.49.46; Mon, 18 Mar 2019 03:49:46 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727628AbfCRKtp (ORCPT + 31 others); 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(+) -- 2.17.1 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.