From patchwork Fri Nov 28 05:26:34 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: AKASHI Takahiro X-Patchwork-Id: 5401571 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 9A1659F443 for ; Fri, 28 Nov 2014 05:30:08 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9F4C920123 for ; Fri, 28 Nov 2014 05:30:07 +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 C663020122 for ; Fri, 28 Nov 2014 05:30:06 +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 1XuE5u-0006Z1-1Z; Fri, 28 Nov 2014 05:27:50 +0000 Received: from mail-pd0-f177.google.com ([209.85.192.177]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XuE5f-0006Ro-Lv for linux-arm-kernel@lists.infradead.org; Fri, 28 Nov 2014 05:27:36 +0000 Received: by mail-pd0-f177.google.com with SMTP id ft15so5966789pdb.22 for ; Thu, 27 Nov 2014 21:27:16 -0800 (PST) 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=LrbNTUzgAR26sVwEbltHr79Cq+d03K2DyomBM0o7XFk=; b=fcXOtiDsNuJf/R1L7FsxvXdVyoacuahgrGbC3+ze++CDq6vqdklOMRYE/Ua1p9YbWS +bmCn4qqayyeNDryghMwNeHCaOgUbZDXe7xcDLyz2MVX1P2VhK4nJgvNN4ip1PBrMnVz TH94yGxuFyjJ/kBzGg8ERHN7bUTk41gulPyvFvea8WxbUrDHDY66rtXvukCdWeWyFZzA mSTpOMyXDfqYEQQLlcOeDL6Qy4dLWbg2dUj8wojKyINbvNNJD18FqYHbK+JEv9FhVFod XP6a9bMIBCgOiFhxDNEV9vHlWOtxnK1kb/J2rktzZecSuNLy/Py2B1+vkUNEYrJY6aYp LCrg== X-Gm-Message-State: ALoCoQnKlH7l7h5Dx+aBnGAcLHmEU/0UloZ9dLOvkVISgWHk3+dFa7VCFi6nM3PeVAaEE+2r4a5m X-Received: by 10.68.65.112 with SMTP id w16mr69500735pbs.114.1417152436427; Thu, 27 Nov 2014 21:27:16 -0800 (PST) Received: from localhost.localdomain (KD182249096114.au-net.ne.jp. [182.249.96.114]) by mx.google.com with ESMTPSA id kp2sm8661866pdb.30.2014.11.27.21.27.11 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 27 Nov 2014 21:27:15 -0800 (PST) From: AKASHI Takahiro To: keescook@chromium.org, catalin.marinas@arm.com, will.deacon@arm.com Subject: [PATCH v10 1/6] arm64: ptrace: add NT_ARM_SYSTEM_CALL regset Date: Fri, 28 Nov 2014 14:26:34 +0900 Message-Id: <1417152399-32717-2-git-send-email-takahiro.akashi@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1417152399-32717-1-git-send-email-takahiro.akashi@linaro.org> References: <1417152399-32717-1-git-send-email-takahiro.akashi@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141127_212735_838263_4EDFF009 X-CRM114-Status: GOOD ( 13.71 ) X-Spam-Score: -0.7 (/) 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=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_LOW, T_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 This regeset is intended to be used to get and set a system call number while tracing. There was some discussion about possible approaches to do so: (1) modify x8 register with ptrace(PTRACE_SETREGSET) indirectly, and update regs->syscallno later on in syscall_trace_enter(), or (2) define a dedicated regset for this purpose as on s390, or (3) support ptrace(PTRACE_SET_SYSCALL) as on arch/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, especially case of -1, to be visible before this function returns in syscall_trace_enter(), (1) doesn't work well. We will take (2) since it looks much cleaner. Signed-off-by: AKASHI Takahiro --- arch/arm64/kernel/ptrace.c | 35 +++++++++++++++++++++++++++++++++++ include/uapi/linux/elf.h | 1 + 2 files changed, 36 insertions(+) diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 8a4ae8e..f576781 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -551,6 +551,32 @@ static int tls_set(struct task_struct *target, const struct user_regset *regset, return ret; } +static int system_call_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + int syscallno = task_pt_regs(target)->syscallno; + + return user_regset_copyout(&pos, &count, &kbuf, &ubuf, + &syscallno, 0, -1); +} + +static int system_call_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + int syscallno, ret; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &syscallno, 0, -1); + if (ret) + return ret; + + task_pt_regs(target)->syscallno = syscallno; + return ret; +} + enum aarch64_regset { REGSET_GPR, REGSET_FPR, @@ -559,6 +585,7 @@ enum aarch64_regset { REGSET_HW_BREAK, REGSET_HW_WATCH, #endif + REGSET_SYSTEM_CALL, }; static const struct user_regset aarch64_regsets[] = { @@ -608,6 +635,14 @@ static const struct user_regset aarch64_regsets[] = { .set = hw_break_set, }, #endif + [REGSET_SYSTEM_CALL] = { + .core_note_type = NT_ARM_SYSTEM_CALL, + .n = 1, + .size = sizeof(int), + .align = sizeof(int), + .get = system_call_get, + .set = system_call_set, + }, }; static const struct user_regset_view user_aarch64_view = { diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h index ea9bf25..71e1d0e 100644 --- a/include/uapi/linux/elf.h +++ b/include/uapi/linux/elf.h @@ -397,6 +397,7 @@ typedef struct elf64_shdr { #define NT_ARM_TLS 0x401 /* ARM TLS register */ #define NT_ARM_HW_BREAK 0x402 /* ARM hardware breakpoint registers */ #define NT_ARM_HW_WATCH 0x403 /* ARM hardware watchpoint registers */ +#define NT_ARM_SYSTEM_CALL 0x404 /* ARM system call number */ #define NT_METAG_CBUF 0x500 /* Metag catch buffer registers */ #define NT_METAG_RPIPE 0x501 /* Metag read pipeline state */ #define NT_METAG_TLS 0x502 /* Metag TLS pointer */