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
16 /* workaround for -Wmissing-prototypes warnings */
17 int __vdso_clock_gettime(clockid_t clock, struct __kernel_old_timespec *ts);
18 int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz);
19 __kernel_old_time_t __vdso_time(__kernel_old_time_t *t);
20 long __vdso_getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *unused);
21
22 int __vdso_clock_gettime(clockid_t clock, struct __kernel_old_timespec *ts)
23 {
24 long ret;
25
26 asm("syscall"
27 : "=a" (ret)
28 : "" (__NR_clock_gettime), "D" (clock), "S" (ts)
29 : "rcx", "r11", "memory");
30
31 return ret;
32 }
33 int clock_gettime(clockid_t, struct __kernel_old_timespec *)
34 __attribute__((weak, alias("__vdso_clock_gettime")));
35
36 int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
37 {
38 long ret;
39
40 asm("syscall"
41 : "=a" (ret)
42 : "" (__NR_gettimeofday), "D" (tv), "S" (tz)
43 : "rcx", "r11", "memory");
44
45 return ret;
46 }
47 int gettimeofday(struct __kernel_old_timeval *, struct timezone *)
48 __attribute__((weak, alias("__vdso_gettimeofday")));
49
50 __kernel_old_time_t __vdso_time(__kernel_old_time_t *t)
51 {
52 long secs;
53
54 asm volatile("syscall"
55 : "=a" (secs)
56 : "" (__NR_time), "D" (t) : "cc", "r11", "cx", "memory");
57
58 return secs;
59 }
60 __kernel_old_time_t time(__kernel_old_time_t *t) __attribute__((weak, alias("__vdso_time")));
61
62 long
63 __vdso_getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *unused)
64 {
65 /*
66 * UML does not support SMP, we can cheat here. :)
67 */
68
69 if (cpu)
70 *cpu = 0;
71 if (node)
72 *node = 0;
73
74 return 0;
75 }
76
77 long getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *tcache)
78 __attribute__((weak, alias("__vdso_getcpu")));
79
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