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/elf.h>
29 #include <sys/errno.h>
30 #include <sys/proc.h>
31 #include <sys/stddef.h>
32 #define _KERNEL
33 #include <sys/vdso.h>
34 #undef _KERNEL
35 #include <stdbool.h>
36
37 #include <machine/atomic.h>
38 #include <machine/cpufunc.h>
39 #include <machine/stdarg.h>
40
41 #include <i386/linux/linux.h>
42 #include <i386/linux/linux_syscall.h>
43 #include <compat/linux/linux_errno.h>
44 #include <compat/linux/linux_time.h>
45
46 /* The kernel fixup this at vDSO install */
47 uintptr_t *kern_timekeep_base = NULL;
48 uint32_t kern_tsc_selector = 0;
49 uint32_t kern_cpu_selector = 0;
50
51 #include <x86/linux/linux_vdso_gettc_x86.inc>
52 #include <x86/linux/linux_vdso_getcpu_x86.inc>
53
54 static int
write(int fd,const void * buf,size_t size)55 write(int fd, const void *buf, size_t size)
56 {
57 int res;
58
59 __asm__ __volatile__
60 (
61 "int $0x80"
62 : "=a"(res)
63 : "a"(LINUX_SYS_linux_write), "b"(fd), "c"(buf), "d"(size)
64 : "cc", "memory"
65 );
66 return (res);
67 }
68
69 static int
__vdso_clock_gettime_fallback(clockid_t clock_id,struct l_timespec * ts)70 __vdso_clock_gettime_fallback(clockid_t clock_id, struct l_timespec *ts)
71 {
72 int res;
73
74 __asm__ __volatile__
75 (
76 "int $0x80"
77 : "=a"(res)
78 : "a"(LINUX_SYS_linux_clock_gettime), "b"(clock_id), "c"(ts)
79 : "cc", "memory"
80 );
81 return (res);
82 }
83
84 static int
__vdso_clock_gettime64_fallback(clockid_t clock_id,struct l_timespec64 * ts)85 __vdso_clock_gettime64_fallback(clockid_t clock_id, struct l_timespec64 *ts)
86 {
87 int res;
88
89 __asm__ __volatile__
90 (
91 "int $0x80"
92 : "=a"(res)
93 : "a"(LINUX_SYS_linux_clock_gettime64), "b"(clock_id), "c"(ts)
94 : "cc", "memory"
95 );
96 return (res);
97 }
98
99 static int
__vdso_gettimeofday_fallback(l_timeval * tv,struct timezone * tz)100 __vdso_gettimeofday_fallback(l_timeval *tv, struct timezone *tz)
101 {
102 int res;
103
104 __asm__ __volatile__
105 (
106 "int $0x80"
107 : "=a"(res)
108 : "a"(LINUX_SYS_gettimeofday), "b"(tv), "c"(tz)
109 : "cc", "memory"
110 );
111 return (res);
112 }
113
114 static int
__vdso_clock_getres_fallback(clockid_t clock_id,struct l_timespec * ts)115 __vdso_clock_getres_fallback(clockid_t clock_id, struct l_timespec *ts)
116 {
117 int res;
118
119 __asm__ __volatile__
120 (
121 "int $0x80"
122 : "=a"(res)
123 : "a"(LINUX_SYS_linux_clock_getres), "b"(clock_id), "c"(ts)
124 : "cc", "memory"
125 );
126 return (res);
127 }
128
129 static int
__vdso_getcpu_fallback(uint32_t * cpu,uint32_t * node,void * cache)130 __vdso_getcpu_fallback(uint32_t *cpu, uint32_t *node, void *cache)
131 {
132 int res;
133
134 __asm__ __volatile__
135 (
136 "int $0x80"
137 : "=a"(res)
138 : "a"(LINUX_SYS_linux_getcpu), "D"(cpu), "S"(node), "d"(cache)
139 : "cc", "memory"
140 );
141 return (res);
142 }
143
144 static int
__vdso_time_fallback(long * tm)145 __vdso_time_fallback(long *tm)
146 {
147 int res;
148
149 __asm__ __volatile__
150 (
151 "int $0x80"
152 : "=a"(res)
153 : "a"(LINUX_SYS_linux_time), "b"(tm)
154 : "cc", "memory"
155 );
156 return (res);
157 }
158
159 #include <compat/linux/linux_vdso_gtod.inc>
160