1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
4 *
5 * This vDSO turns all calls into a syscall so that UML can trap them.
6 */
7
8
9/* Disable profiling for userspace code */
10#define DISABLE_BRANCH_PROFILING
11
12#include <vdso/gettime.h>
13#include <linux/time.h>
14#include <asm/unistd.h>
15
16int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
17{
18 long ret;
19
20 asm("syscall"
21 : "=a" (ret)
22 : "0" (__NR_clock_gettime), "D" (clock), "S" (ts)
23 : "rcx", "r11", "memory");
24
25 return ret;
26}
27int clock_gettime(clockid_t, struct __kernel_timespec *)
28 __attribute__((weak, alias("__vdso_clock_gettime")));
29
30int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
31{
32 long ret;
33
34 asm("syscall"
35 : "=a" (ret)
36 : "0" (__NR_gettimeofday), "D" (tv), "S" (tz)
37 : "rcx", "r11", "memory");
38
39 return ret;
40}
41int gettimeofday(struct __kernel_old_timeval *, struct timezone *)
42 __attribute__((weak, alias("__vdso_gettimeofday")));
43
44__kernel_old_time_t __vdso_time(__kernel_old_time_t *t)
45{
46 long secs;
47
48 asm volatile("syscall"
49 : "=a" (secs)
50 : "0" (__NR_time), "D" (t) : "cc", "r11", "cx", "memory");
51
52 return secs;
53}
54__kernel_old_time_t time(__kernel_old_time_t *t) __attribute__((weak, alias("__vdso_time")));
55

source code of linux/arch/x86/um/vdso/um_vdso.c