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 <linux/time.h>
13#include <linux/getcpu.h>
14#include <asm/unistd.h>
15
16int __vdso_clock_gettime(clockid_t clock, struct __kernel_old_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_old_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
56long
57__vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)
58{
59	/*
60	 * UML does not support SMP, we can cheat here. :)
61	 */
62
63	if (cpu)
64		*cpu = 0;
65	if (node)
66		*node = 0;
67
68	return 0;
69}
70
71long getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
72	__attribute__((weak, alias("__vdso_getcpu")));
73