Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753070AbbGKGK5 (ORCPT ); Sat, 11 Jul 2015 02:10:57 -0400 Received: from mail-yk0-f173.google.com ([209.85.160.173]:35185 "EHLO mail-yk0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752974AbbGKGKy (ORCPT ); Sat, 11 Jul 2015 02:10:54 -0400 From: Brian Gerst To: x86@kernel.org, linux-kernel@vger.kernel.org Cc: Ingo Molnar , "H. Peter Anvin" , Denys Vlasenko , Andy Lutomirski , Linus Torvalds Subject: [PATCH 1/5] x86/vm86: Move userspace accesses to do_sys_vm86() Date: Sat, 11 Jul 2015 01:09:16 -0400 Message-Id: <1436591360-16210-2-git-send-email-brgerst@gmail.com> X-Mailer: git-send-email 2.4.3 In-Reply-To: <1436591360-16210-1-git-send-email-brgerst@gmail.com> References: <1436591360-16210-1-git-send-email-brgerst@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4117 Lines: 123 Move the userspace accesses down into the common function in preparation for the next set of patches. Signed-off-by: Brian Gerst --- arch/x86/kernel/vm86_32.c | 61 +++++++++++++++++++++-------------------------- 1 file changed, 27 insertions(+), 34 deletions(-) diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c index fc9db6e..71a8b0a 100644 --- a/arch/x86/kernel/vm86_32.c +++ b/arch/x86/kernel/vm86_32.c @@ -200,7 +200,8 @@ out: static int do_vm86_irq_handling(int subfunction, int irqnumber); -static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk); +static long do_sys_vm86(struct vm86plus_struct __user *v86, bool plus, + struct kernel_vm86_struct *info); SYSCALL_DEFINE1(vm86old, struct vm86_struct __user *, v86) { @@ -209,21 +210,8 @@ SYSCALL_DEFINE1(vm86old, struct vm86_struct __user *, v86) * This remains on the stack until we * return to 32 bit user space. */ - struct task_struct *tsk = current; - int tmp; - if (tsk->thread.saved_sp0) - return -EPERM; - tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs, - offsetof(struct kernel_vm86_struct, vm86plus) - - sizeof(info.regs)); - if (tmp) - return -EFAULT; - memset(&info.vm86plus, 0, (int)&info.regs32 - (int)&info.vm86plus); - info.regs32 = current_pt_regs(); - tsk->thread.vm86_info = v86; - do_sys_vm86(&info, tsk); - return 0; /* we never return here */ + return do_sys_vm86((struct vm86plus_struct __user *) v86, false, &info); } @@ -234,11 +222,7 @@ SYSCALL_DEFINE2(vm86, unsigned long, cmd, unsigned long, arg) * This remains on the stack until we * return to 32 bit user space. */ - struct task_struct *tsk; - int tmp; - struct vm86plus_struct __user *v86; - tsk = current; switch (cmd) { case VM86_REQUEST_IRQ: case VM86_FREE_IRQ: @@ -256,25 +240,34 @@ SYSCALL_DEFINE2(vm86, unsigned long, cmd, unsigned long, arg) } /* we come here only for functions VM86_ENTER, VM86_ENTER_NO_BYPASS */ - if (tsk->thread.saved_sp0) - return -EPERM; - v86 = (struct vm86plus_struct __user *)arg; - tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs, - offsetof(struct kernel_vm86_struct, regs32) - - sizeof(info.regs)); - if (tmp) - return -EFAULT; - info.regs32 = current_pt_regs(); - info.vm86plus.is_vm86pus = 1; - tsk->thread.vm86_info = (struct vm86_struct __user *)v86; - do_sys_vm86(&info, tsk); - return 0; /* we never return here */ + return do_sys_vm86((struct vm86plus_struct __user *) arg, true, &info); } -static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk) +static long do_sys_vm86(struct vm86plus_struct __user *v86, bool plus, + struct kernel_vm86_struct *info) { struct tss_struct *tss; + struct task_struct *tsk = current; + + if (tsk->thread.saved_sp0) + return -EPERM; + if (plus) { + if (copy_vm86_regs_from_user(&info->regs, &v86->regs, + offsetof(struct kernel_vm86_struct, regs32) - + sizeof(info->regs))) + return -EFAULT; + info->vm86plus.is_vm86pus = 1; + } else { + if (copy_vm86_regs_from_user(&info->regs, &v86->regs, + offsetof(struct kernel_vm86_struct, vm86plus) - + sizeof(info->regs))) + return -EFAULT; + memset(&info->vm86plus, 0, sizeof(struct vm86plus_info_struct)); + } + info->regs32 = current_pt_regs(); + tsk->thread.vm86_info = (struct vm86_struct __user *) v86; + /* * make sure the vm86() system call doesn't try to do anything silly */ @@ -344,7 +337,7 @@ static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk "jmp resume_userspace" : /* no outputs */ :"r" (&info->regs), "r" (task_thread_info(tsk)), "r" (0)); - /* we never return here */ + return 0; /* we never return here */ } static inline void return_to_32bit(struct kernel_vm86_regs *regs16, int retval) -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/