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Subject[PATCH 1/5] x86/vm86: Move userspace accesses to do_sys_vm86()
Date
Move the userspace accesses down into the common function in
preparation for the next set of patches.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
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


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