From patchwork Mon May 14 09:46:29 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 135707 Delivered-To: patch@linaro.org Received: by 2002:a2e:9706:0:0:0:0:0 with SMTP id r6-v6csp1531840lji; Mon, 14 May 2018 02:47:48 -0700 (PDT) X-Google-Smtp-Source: AB8JxZrf0dCPvWmSup+q3/2Hg60+49v8exBbcaodnCYcD5PQQMJ+ro+169KdqwBn/gyRw4srGThm X-Received: by 2002:a17:902:145:: with SMTP id 63-v6mr9235310plb.332.1526291268317; Mon, 14 May 2018 02:47:48 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1526291268; cv=none; d=google.com; s=arc-20160816; b=yAsmniGVO0g4JRzYDxcQe68pqASMIvWQ5NHzh8TvUkAuaOivXyKoLQs0jbk4c3jJ48 irH/n386I40gxmFE5rmoKHA6fugUNKcmQ5NYqlJYE0mJEegJ+xMgrpy2cCZALihK8Z+l To2QKx3kmBvTkI5U91dr4DmnuSJC3lt5As3mKT8++oo2Fp/wFO4Bfo3JW0OYG5mRDcrb X/DojMEjghs7oG7VkV66YsOuRDW/3ujwAn8CB7Lz8RnB3SwSUWAkvl1x55yQQ3WboUbY JODiVRYdBVQ3Rk0l25OZPyb/DGYLMCFbfz9jxQIiFU15DFZ3PTynPnV5r1ZtyYZg0nPy NPQg== 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:arc-authentication-results; bh=wA9AO/3Aa5kSlfWEzZWGCD3vEn+qGJNbv1Kix1Xqug0=; b=ealij9oVIHrKynGaw+sVLSxHZsLFLVuA81VnsvwwIyDyBt+PzwN4i46WRuZC2F/pnb Tol6uFMHvyAJ+PlxRjZ5dIFn32I30ZRV3Z9hhf+d8jppsJB8PuIvPU4rTAjA2dIH3V0C VL6cdhoYVbb709TJF9qppqhI90iAqkwl3p1pcTJyPOpAqXrXQmY/F2bGI1OTexj4bKqD BQ7/T7c6h05vSV6EukSm0yqBY4efcUpfhO+ZH3Gg1p7YdqhsReGsvF77yPmRjHv6R5et lKSQwDXKr57CoMPZLut/s+S4UrA1+OVxyzd0ZJvSG+zmFs1ZN1chucHU0TRP/4bIaBut 3tfA== 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 p8-v6si2141964pgs.441.2018.05.14.02.47.47; Mon, 14 May 2018 02:47:48 -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 S1751498AbeENJrm (ORCPT + 29 others); Mon, 14 May 2018 05:47:42 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:38264 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752497AbeENJrk (ORCPT ); Mon, 14 May 2018 05:47:40 -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 4B56F169F; Mon, 14 May 2018 02:47:40 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 5DAB93F25D; Mon, 14 May 2018 02:47:38 -0700 (PDT) From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, catalin.marinas@arm.com, dave.martin@arm.com, james.morse@arm.com, linux@dominikbrodowski.net, linux-fsdevel@vger.kernel.org, marc.zyngier@arm.com, mark.rutland@arm.com, viro@zeniv.linux.org.uk, will.deacon@arm.com Subject: [PATCH 07/18] arm64: remove sigreturn wrappers Date: Mon, 14 May 2018 10:46:29 +0100 Message-Id: <20180514094640.27569-8-mark.rutland@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180514094640.27569-1-mark.rutland@arm.com> References: <20180514094640.27569-1-mark.rutland@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The arm64 sigreturn* syscall handlers are non-standard. Rather than taking a number of user parameters in registers as per the AAPCS, they expect the pt_regs as their sole argument. To make this work, we override the syscall definitions to invoke wrappers written in assembly, which mov the SP into x0, and branch to their respective C functions. On other architectures (such as x86), the sigreturn* functions take no argument and instead use current_pt_regs() to acquire the user registers. This requires less boilerplate code, and allows for other features such as interposing C code in this path. This patch takes the same approach for arm64. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon --- arch/arm64/include/asm/unistd32.h | 4 ++-- arch/arm64/kernel/entry.S | 8 -------- arch/arm64/kernel/entry32.S | 10 ---------- arch/arm64/kernel/signal.c | 3 ++- arch/arm64/kernel/signal32.c | 6 ++++-- arch/arm64/kernel/sys.c | 3 +-- arch/arm64/kernel/sys32.c | 4 ++-- 7 files changed, 11 insertions(+), 27 deletions(-) -- 2.11.0 diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h index ef292160748c..ab95554b1734 100644 --- a/arch/arm64/include/asm/unistd32.h +++ b/arch/arm64/include/asm/unistd32.h @@ -260,7 +260,7 @@ __SYSCALL(117, sys_ni_syscall) #define __NR_fsync 118 __SYSCALL(__NR_fsync, sys_fsync) #define __NR_sigreturn 119 -__SYSCALL(__NR_sigreturn, compat_sys_sigreturn_wrapper) +__SYSCALL(__NR_sigreturn, compat_sys_sigreturn) #define __NR_clone 120 __SYSCALL(__NR_clone, sys_clone) #define __NR_setdomainname 121 @@ -368,7 +368,7 @@ __SYSCALL(__NR_getresgid, sys_getresgid16) #define __NR_prctl 172 __SYSCALL(__NR_prctl, sys_prctl) #define __NR_rt_sigreturn 173 -__SYSCALL(__NR_rt_sigreturn, compat_sys_rt_sigreturn_wrapper) +__SYSCALL(__NR_rt_sigreturn, compat_sys_rt_sigreturn) #define __NR_rt_sigaction 174 __SYSCALL(__NR_rt_sigaction, compat_sys_rt_sigaction) #define __NR_rt_sigprocmask 175 diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index ec2ee720e33e..08ea3cbfb08f 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -1108,14 +1108,6 @@ __entry_tramp_data_start: #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ /* - * Special system call wrappers. - */ -ENTRY(sys_rt_sigreturn_wrapper) - mov x0, sp - b sys_rt_sigreturn -ENDPROC(sys_rt_sigreturn_wrapper) - -/* * Register switch for AArch64. The callee-saved registers need to be saved * and restored. On entry: * x0 = previous task_struct (must be preserved across the switch) diff --git a/arch/arm64/kernel/entry32.S b/arch/arm64/kernel/entry32.S index f332d5d1f6b4..f9461696dde4 100644 --- a/arch/arm64/kernel/entry32.S +++ b/arch/arm64/kernel/entry32.S @@ -30,16 +30,6 @@ * System call wrappers for the AArch32 compatibility layer. */ -ENTRY(compat_sys_sigreturn_wrapper) - mov x0, sp - b compat_sys_sigreturn -ENDPROC(compat_sys_sigreturn_wrapper) - -ENTRY(compat_sys_rt_sigreturn_wrapper) - mov x0, sp - b compat_sys_rt_sigreturn -ENDPROC(compat_sys_rt_sigreturn_wrapper) - ENTRY(compat_sys_statfs64_wrapper) mov w3, #84 cmp w1, #88 diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 8e624fec4707..caa7a68cf2d2 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -538,8 +538,9 @@ static int restore_sigframe(struct pt_regs *regs, return err; } -asmlinkage long sys_rt_sigreturn(struct pt_regs *regs) +asmlinkage long sys_rt_sigreturn(void) { + struct pt_regs *regs = current_pt_regs(); struct rt_sigframe __user *frame; /* Always make any pending restarted system calls return -EINTR */ diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c index 77b91f478995..cb10588a7cb2 100644 --- a/arch/arm64/kernel/signal32.c +++ b/arch/arm64/kernel/signal32.c @@ -282,8 +282,9 @@ static int compat_restore_sigframe(struct pt_regs *regs, return err; } -asmlinkage int compat_sys_sigreturn(struct pt_regs *regs) +asmlinkage int compat_sys_sigreturn(void) { + struct pt_regs *regs = current_pt_regs(); struct compat_sigframe __user *frame; /* Always make any pending restarted system calls return -EINTR */ @@ -312,8 +313,9 @@ asmlinkage int compat_sys_sigreturn(struct pt_regs *regs) return 0; } -asmlinkage int compat_sys_rt_sigreturn(struct pt_regs *regs) +asmlinkage int compat_sys_rt_sigreturn(void) { + struct pt_regs *regs = current_pt_regs(); struct compat_rt_sigframe __user *frame; /* Always make any pending restarted system calls return -EINTR */ diff --git a/arch/arm64/kernel/sys.c b/arch/arm64/kernel/sys.c index 72981bae10eb..31045f3fed92 100644 --- a/arch/arm64/kernel/sys.c +++ b/arch/arm64/kernel/sys.c @@ -48,8 +48,7 @@ SYSCALL_DEFINE1(arm64_personality, unsigned int, personality) /* * Wrappers to pass the pt_regs argument. */ -asmlinkage long sys_rt_sigreturn_wrapper(void); -#define sys_rt_sigreturn sys_rt_sigreturn_wrapper +asmlinkage long sys_rt_sigreturn(void); #define sys_personality sys_arm64_personality #undef __SYSCALL diff --git a/arch/arm64/kernel/sys32.c b/arch/arm64/kernel/sys32.c index a40b1343b819..1ef103c95410 100644 --- a/arch/arm64/kernel/sys32.c +++ b/arch/arm64/kernel/sys32.c @@ -25,8 +25,8 @@ #include #include -asmlinkage long compat_sys_sigreturn_wrapper(void); -asmlinkage long compat_sys_rt_sigreturn_wrapper(void); +asmlinkage long compat_sys_sigreturn(void); +asmlinkage long compat_sys_rt_sigreturn(void); asmlinkage long compat_sys_statfs64_wrapper(void); asmlinkage long compat_sys_fstatfs64_wrapper(void); asmlinkage long compat_sys_pread64_wrapper(void);