1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2021 Dmitry Chagin <dchagin@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 #include <sys/elf.h>
30 #include <sys/errno.h>
31 #include <sys/proc.h>
32 #include <sys/stddef.h>
33 #define _KERNEL
34 #include <sys/vdso.h>
35 #undef _KERNEL
36 #include <stdbool.h>
37
38 #include <machine/atomic.h>
39 #include <machine/cpufunc.h>
40 #include <machine/stdarg.h>
41
42 #include <amd64/linux/linux.h>
43 #include <amd64/linux/linux_syscall.h>
44 #include <compat/linux/linux_errno.h>
45 #include <compat/linux/linux_time.h>
46
47 /* The kernel fixup this at vDSO install */
48 uintptr_t *kern_timekeep_base = NULL;
49 uint32_t kern_tsc_selector = 0;
50 uint32_t kern_cpu_selector = 0;
51
52 #include <x86/linux/linux_vdso_gettc_x86.inc>
53 #include <x86/linux/linux_vdso_getcpu_x86.inc>
54
55 /* for debug purpose */
56 static int
write(int fd,const void * buf,size_t size)57 write(int fd, const void *buf, size_t size)
58 {
59 int res;
60
61 __asm__ __volatile__
62 (
63 "syscall"
64 : "=a"(res)
65 : "a"(LINUX_SYS_write), "D"(fd), "S"(buf), "d"(size)
66 : "cc", "rcx", "r11", "memory"
67 );
68 return (res);
69 }
70
71 static int
__vdso_clock_gettime_fallback(clockid_t clock_id,struct l_timespec * ts)72 __vdso_clock_gettime_fallback(clockid_t clock_id, struct l_timespec *ts)
73 {
74 int res;
75
76 __asm__ __volatile__
77 (
78 "syscall"
79 : "=a"(res)
80 : "a"(LINUX_SYS_linux_clock_gettime), "D"(clock_id), "S"(ts)
81 : "cc", "rcx", "r11", "memory"
82 );
83 return (res);
84 }
85
86 static int
__vdso_gettimeofday_fallback(l_timeval * tv,struct timezone * tz)87 __vdso_gettimeofday_fallback(l_timeval *tv, struct timezone *tz)
88 {
89 int res;
90
91 __asm__ __volatile__
92 (
93 "syscall"
94 : "=a"(res)
95 : "a"(LINUX_SYS_gettimeofday), "D"(tv), "S"(tz)
96 : "cc", "rcx", "r11", "memory"
97 );
98 return (res);
99 }
100
101 static int
__vdso_clock_getres_fallback(clockid_t clock_id,struct l_timespec * ts)102 __vdso_clock_getres_fallback(clockid_t clock_id, struct l_timespec *ts)
103 {
104 int res;
105
106 __asm__ __volatile__
107 (
108 "syscall"
109 : "=a"(res)
110 : "a"(LINUX_SYS_linux_clock_getres), "D"(clock_id), "S"(ts)
111 : "cc", "rcx", "r11", "memory"
112 );
113 return (res);
114 }
115
116 static int
__vdso_getcpu_fallback(uint32_t * cpu,uint32_t * node,void * cache)117 __vdso_getcpu_fallback(uint32_t *cpu, uint32_t *node, void *cache)
118 {
119 int res;
120
121 __asm__ __volatile__
122 (
123 "syscall"
124 : "=a"(res)
125 : "a"(LINUX_SYS_linux_getcpu), "D"(cpu), "S"(node), "d"(cache)
126 : "cc", "rcx", "r11", "memory"
127 );
128 return (res);
129 }
130
131 static int
__vdso_time_fallback(long * tm)132 __vdso_time_fallback(long *tm)
133 {
134 int res;
135
136 __asm__ __volatile__
137 (
138 "syscall"
139 : "=a"(res)
140 : "a"(LINUX_SYS_linux_time), "D"(tm)
141 : "cc", "rcx", "r11", "memory"
142 );
143 return (res);
144 }
145
146 #include <compat/linux/linux_vdso_gtod.inc>
147