From patchwork Thu Oct 2 09:46:11 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: AKASHI Takahiro X-Patchwork-Id: 5017371 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 273D7BEEA6 for ; Thu, 2 Oct 2014 09:49:29 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 534E520270 for ; Thu, 2 Oct 2014 09:49:28 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7581220259 for ; Thu, 2 Oct 2014 09:49:27 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XZcyv-0006tC-BK; Thu, 02 Oct 2014 09:47:29 +0000 Received: from mail-pa0-f51.google.com ([209.85.220.51]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XZcys-0006gj-Gc for linux-arm-kernel@lists.infradead.org; Thu, 02 Oct 2014 09:47:27 +0000 Received: by mail-pa0-f51.google.com with SMTP id lj1so1947410pab.38 for ; Thu, 02 Oct 2014 02:47:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=p+vWjR91lJIx3IlBewdzq2shg5awcxNqsm4vbjXYDCs=; b=SCp8mrreSXJ6/lQtO4hSGUfkxvChP7/8qo6fKM7vfiphWHe7/gN1o7umjCsg4+StKZ Wdi6OOtg/EW5rA62HagAQgFztP9KKScAN5LcOlnrpZOoh+0MHGqaiFEMkrrXiF4Us/Q5 9oHlYqLEkVnNKsQcDiIvDnbq6jY2Ew5iTBbji1Edc/IA8aYvcinaxExzSBvBzsDB/Tom jY5lOrpAiZmvDfFftWi96WDKkr1n+GbK/EMoBcqwL5BLMVd/mKv/BglXT0huZoKTwnTZ MAam83ftqTfMnIVzw9ERGoDw+HSIihkMD0ryUu1rXFzRBAxqJlUBvKrIEDjboNWnLEME Qc2w== X-Gm-Message-State: ALoCoQknYr6xWW1SMD3/6myWbEmFfX7IyEWQVSDuv0NETKK7JPD2Fk7ci7Sqvp7VZualvTC1Y834 X-Received: by 10.66.90.137 with SMTP id bw9mr85459574pab.7.1412243225309; Thu, 02 Oct 2014 02:47:05 -0700 (PDT) Received: from localhost.localdomain (KD182249093205.au-net.ne.jp. [182.249.93.205]) by mx.google.com with ESMTPSA id w7sm3013036pbs.4.2014.10.02.02.47.00 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 02 Oct 2014 02:47:04 -0700 (PDT) From: AKASHI Takahiro To: keescook@chromium.org, catalin.marinas@arm.com, will.deacon@arm.com Subject: [PATCH v7 1/6] arm64: ptrace: add PTRACE_SET_SYSCALL Date: Thu, 2 Oct 2014 18:46:11 +0900 Message-Id: <1412243176-16192-2-git-send-email-takahiro.akashi@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1412243176-16192-1-git-send-email-takahiro.akashi@linaro.org> References: <1412243176-16192-1-git-send-email-takahiro.akashi@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141002_024726_593346_6B031BF0 X-CRM114-Status: GOOD ( 11.87 ) X-Spam-Score: -0.9 (/) Cc: linaro-kernel@lists.linaro.org, arndb@arndb.de, linux-kernel@vger.kernel.org, AKASHI Takahiro , dsaxena@linaro.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP To allow tracer to be able to change/skip a system call by re-writing a syscall number, there are several approaches: (1) modify x8 register with ptrace(PTRACE_SETREGSET), and handle this case later on in syscall_trace_enter(), or (2) support ptrace(PTRACE_SET_SYSCALL) as on arm Thinking of the fact that user_pt_regs doesn't expose 'syscallno' to tracer as well as that secure_computing() expects a changed syscall number to be visible, especially case of -1, before this function returns in syscall_trace_enter(), we'd better take (2). Reviewed-by: Kees Cook Signed-off-by: AKASHI Takahiro --- arch/arm64/include/uapi/asm/ptrace.h | 1 + arch/arm64/kernel/ptrace.c | 14 +++++++++++++- 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/uapi/asm/ptrace.h b/arch/arm64/include/uapi/asm/ptrace.h index 6913643..49c6174 100644 --- a/arch/arm64/include/uapi/asm/ptrace.h +++ b/arch/arm64/include/uapi/asm/ptrace.h @@ -23,6 +23,7 @@ #include +#define PTRACE_SET_SYSCALL 23 /* * PSR bits diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index fe63ac5..2842f9f 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -1082,7 +1082,19 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task) long arch_ptrace(struct task_struct *child, long request, unsigned long addr, unsigned long data) { - return ptrace_request(child, request, addr, data); + int ret; + + switch (request) { + case PTRACE_SET_SYSCALL: + task_pt_regs(child)->syscallno = data; + ret = 0; + break; + default: + ret = ptrace_request(child, request, addr, data); + break; + } + + return ret; } enum ptrace_syscall_dir {