[ 027/102] x86, vm86: fix VM86 syscalls: use SYSCALL_DEFINEx(...)

From: Greg Kroah-Hartman
Date: Fri May 17 2013 - 18:21:40 EST


3.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexander van Heukelum <heukelum@xxxxxxxxxxx>

commit 5522ddb3fc0dfd4a503c8278eafd88c9f2d3fada upstream.

Commit 49cb25e9290 x86: 'get rid of pt_regs argument in vm86/vm86old'
got rid of the pt_regs stub for sys_vm86old and sys_vm86. The functions
were, however, not changed to use the calling convention for syscalls.

[AV: killed asmlinkage_protect() - it's done automatically now]

Reported-and-tested-by: Hans de Bruin <jmdebruin@xxxxxxxxx>
Signed-off-by: Alexander van Heukelum <heukelum@xxxxxxxxxxx>
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/include/asm/syscalls.h | 4 ++--
arch/x86/kernel/vm86_32.c | 38 ++++++++++++++------------------------
2 files changed, 16 insertions(+), 26 deletions(-)

--- a/arch/x86/include/asm/syscalls.h
+++ b/arch/x86/include/asm/syscalls.h
@@ -37,8 +37,8 @@ asmlinkage int sys_get_thread_area(struc
unsigned long sys_sigreturn(void);

/* kernel/vm86_32.c */
-int sys_vm86old(struct vm86_struct __user *);
-int sys_vm86(unsigned long, unsigned long);
+asmlinkage long sys_vm86old(struct vm86_struct __user *);
+asmlinkage long sys_vm86(unsigned long, unsigned long);

#else /* CONFIG_X86_32 */

--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -33,6 +33,7 @@
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
+#include <linux/syscalls.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/signal.h>
@@ -48,7 +49,6 @@
#include <asm/io.h>
#include <asm/tlbflush.h>
#include <asm/irq.h>
-#include <asm/syscalls.h>

/*
* Known problems:
@@ -202,36 +202,32 @@ 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);

-int sys_vm86old(struct vm86_struct __user *v86)
+SYSCALL_DEFINE1(vm86old, struct vm86_struct __user *, v86)
{
struct kernel_vm86_struct info; /* declare this _on top_,
* this avoids wasting of stack space.
* This remains on the stack until we
* return to 32 bit user space.
*/
- struct task_struct *tsk;
- int tmp, ret = -EPERM;
+ struct task_struct *tsk = current;
+ int tmp;

- tsk = current;
if (tsk->thread.saved_sp0)
- goto out;
+ return -EPERM;
tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs,
offsetof(struct kernel_vm86_struct, vm86plus) -
sizeof(info.regs));
- ret = -EFAULT;
if (tmp)
- goto out;
+ 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);
- ret = 0; /* we never return here */
-out:
- return ret;
+ return 0; /* we never return here */
}


-int sys_vm86(unsigned long cmd, unsigned long arg)
+SYSCALL_DEFINE2(vm86, unsigned long, cmd, unsigned long, arg)
{
struct kernel_vm86_struct info; /* declare this _on top_,
* this avoids wasting of stack space.
@@ -239,7 +235,7 @@ int sys_vm86(unsigned long cmd, unsigned
* return to 32 bit user space.
*/
struct task_struct *tsk;
- int tmp, ret;
+ int tmp;
struct vm86plus_struct __user *v86;

tsk = current;
@@ -248,8 +244,7 @@ int sys_vm86(unsigned long cmd, unsigned
case VM86_FREE_IRQ:
case VM86_GET_IRQ_BITS:
case VM86_GET_AND_RESET_IRQ:
- ret = do_vm86_irq_handling(cmd, (int)arg);
- goto out;
+ return do_vm86_irq_handling(cmd, (int)arg);
case VM86_PLUS_INSTALL_CHECK:
/*
* NOTE: on old vm86 stuff this will return the error
@@ -257,28 +252,23 @@ int sys_vm86(unsigned long cmd, unsigned
* interpreted as (invalid) address to vm86_struct.
* So the installation check works.
*/
- ret = 0;
- goto out;
+ return 0;
}

/* we come here only for functions VM86_ENTER, VM86_ENTER_NO_BYPASS */
- ret = -EPERM;
if (tsk->thread.saved_sp0)
- goto out;
+ 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));
- ret = -EFAULT;
if (tmp)
- goto out;
+ 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);
- ret = 0; /* we never return here */
-out:
- return ret;
+ return 0; /* we never return here */
}




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