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Diffstat (limited to 'arch/x86/entry/vsyscall/vsyscall_64.c')
-rw-r--r--arch/x86/entry/vsyscall/vsyscall_64.c18
1 files changed, 11 insertions, 7 deletions
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 317be365bce3..70b7845434cb 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -127,6 +127,7 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
int vsyscall_nr, syscall_nr, tmp;
int prev_sig_on_uaccess_err;
long ret;
+ unsigned long orig_dx;
/*
* No point in checking CS -- the only way to get here is a user mode
@@ -227,19 +228,22 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
ret = -EFAULT;
switch (vsyscall_nr) {
case 0:
- ret = sys_gettimeofday(
- (struct timeval __user *)regs->di,
- (struct timezone __user *)regs->si);
+ /* this decodes regs->di and regs->si on its own */
+ ret = __x64_sys_gettimeofday(regs);
break;
case 1:
- ret = sys_time((time_t __user *)regs->di);
+ /* this decodes regs->di on its own */
+ ret = __x64_sys_time(regs);
break;
case 2:
- ret = sys_getcpu((unsigned __user *)regs->di,
- (unsigned __user *)regs->si,
- NULL);
+ /* while we could clobber regs->dx, we didn't in the past... */
+ orig_dx = regs->dx;
+ regs->dx = 0;
+ /* this decodes regs->di, regs->si and regs->dx on its own */
+ ret = __x64_sys_getcpu(regs);
+ regs->dx = orig_dx;
break;
}