From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v3 17/31] arm64: System calls handling Date: Fri, 7 Sep 2012 19:43:36 +0000 Message-ID: <201209071943.37184.arnd@arndb.de> References: <1347035226-18649-1-git-send-email-catalin.marinas@arm.com> <1347035226-18649-18-git-send-email-catalin.marinas@arm.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-path: Received: from moutng.kundenserver.de ([212.227.17.9]:50723 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751024Ab2IGTnr (ORCPT ); Fri, 7 Sep 2012 15:43:47 -0400 In-Reply-To: <1347035226-18649-18-git-send-email-catalin.marinas@arm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Catalin Marinas , Al Viro Cc: linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org On Friday 07 September 2012, Catalin Marinas wrote: > +/* > + * sys_execve() executes a new program. > + */ > +asmlinkage long sys_execve(const char __user *filenamei, > + const char __user *const __user *argv, > + const char __user *const __user *envp, > + struct pt_regs *regs) > +{ > + long error; > + char * filename; > + > + filename = getname(filenamei); > + error = PTR_ERR(filename); > + if (IS_ERR(filename)) > + goto out; > + error = do_execve(filename, argv, envp, regs); > + putname(filename); > +out: > + return error; > +} > + > +int kernel_execve(const char *filename, > + const char *const argv[], > + const char *const envp[]) > +{ > + struct pt_regs regs; > + int ret; > + > + memset(®s, 0, sizeof(struct pt_regs)); > + ret = do_execve(filename, > + (const char __user *const __user *)argv, > + (const char __user *const __user *)envp, ®s); > + if (ret < 0) > + goto out; > + > + /* > + * Save argc to the register structure for userspace. > + */ > + regs.regs[0] = ret; > + > + /* > + * We were successful. We won't be returning to our caller, but > + * instead to user space by manipulating the kernel stack. > + */ > + asm( "add x0, %0, %1\n\t" > + "mov x1, %2\n\t" > + "mov x2, %3\n\t" > + "bl memmove\n\t" /* copy regs to top of stack */ > + "mov x27, #0\n\t" /* not a syscall */ > + "mov x28, %0\n\t" /* thread structure */ > + "mov sp, x0\n\t" /* reposition stack pointer */ > + "b ret_to_user" > + : > + : "r" (current_thread_info()), > + "Ir" (THREAD_START_SP - sizeof(regs)), > + "r" (®s), > + "Ir" (sizeof(regs)) > + : "x0", "x1", "x2", "x27", "x28", "x30", "memory"); > + > + out: > + return ret; > +} Al Viro is currently reworking this code across all architectures, please have a look at https://git.kernel.org/?p=linux/kernel/git/viro/signal.git;a=shortlog;h=refs/heads/execve2 > +EXPORT_SYMBOL(kernel_execve); You certainly don't need to export it. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Fri, 7 Sep 2012 19:43:36 +0000 Subject: [PATCH v3 17/31] arm64: System calls handling In-Reply-To: <1347035226-18649-18-git-send-email-catalin.marinas@arm.com> References: <1347035226-18649-1-git-send-email-catalin.marinas@arm.com> <1347035226-18649-18-git-send-email-catalin.marinas@arm.com> Message-ID: <201209071943.37184.arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Friday 07 September 2012, Catalin Marinas wrote: > +/* > + * sys_execve() executes a new program. > + */ > +asmlinkage long sys_execve(const char __user *filenamei, > + const char __user *const __user *argv, > + const char __user *const __user *envp, > + struct pt_regs *regs) > +{ > + long error; > + char * filename; > + > + filename = getname(filenamei); > + error = PTR_ERR(filename); > + if (IS_ERR(filename)) > + goto out; > + error = do_execve(filename, argv, envp, regs); > + putname(filename); > +out: > + return error; > +} > + > +int kernel_execve(const char *filename, > + const char *const argv[], > + const char *const envp[]) > +{ > + struct pt_regs regs; > + int ret; > + > + memset(®s, 0, sizeof(struct pt_regs)); > + ret = do_execve(filename, > + (const char __user *const __user *)argv, > + (const char __user *const __user *)envp, ®s); > + if (ret < 0) > + goto out; > + > + /* > + * Save argc to the register structure for userspace. > + */ > + regs.regs[0] = ret; > + > + /* > + * We were successful. We won't be returning to our caller, but > + * instead to user space by manipulating the kernel stack. > + */ > + asm( "add x0, %0, %1\n\t" > + "mov x1, %2\n\t" > + "mov x2, %3\n\t" > + "bl memmove\n\t" /* copy regs to top of stack */ > + "mov x27, #0\n\t" /* not a syscall */ > + "mov x28, %0\n\t" /* thread structure */ > + "mov sp, x0\n\t" /* reposition stack pointer */ > + "b ret_to_user" > + : > + : "r" (current_thread_info()), > + "Ir" (THREAD_START_SP - sizeof(regs)), > + "r" (®s), > + "Ir" (sizeof(regs)) > + : "x0", "x1", "x2", "x27", "x28", "x30", "memory"); > + > + out: > + return ret; > +} Al Viro is currently reworking this code across all architectures, please have a look at https://git.kernel.org/?p=linux/kernel/git/viro/signal.git;a=shortlog;h=refs/heads/execve2 > +EXPORT_SYMBOL(kernel_execve); You certainly don't need to export it. Arnd