1 /*
2 * Copyright (c) 2005,2008,2020 The DragonFly Project. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 * 3. Neither the name of The DragonFly Project nor the names of its
15 * contributors may be used to endorse or promote products derived
16 * from this software without specific, prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
24 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
28 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #ifndef _CPU_TLS_H_
33 #define _CPU_TLS_H_
34
35 #ifndef _SYS_TYPES_H_
36 #include <sys/types.h>
37 #endif
38 #ifndef _SYS_TLS_H_
39 #include <sys/tls.h>
40 #endif
41
42 /*
43 * NOTE: the tcb_{self,dtv,pthread,errno) fields must be declared
44 * in the structure in the specified order as assembly will access the
45 * fields with a hardwired offset.
46 *
47 * Outside of this file, the system call layer generation will hardwire
48 * the offset for tcb_errno.
49 */
50 struct tls_tcb {
51 struct tls_tcb *tcb_self; /* pointer to self*/
52 void *tcb_dtv; /* Dynamic Thread Vector */
53 void *tcb_pthread; /* thread library's data*/
54 int *tcb_errno_p; /* pointer to per-thread errno */
55 void *tcb_segstack; /* used for segmented stacks */
56 /* e.g. by LLVM to store stack bound */
57 /* NOTE: do not reorder this field */
58 /* as LLVM uses a fixed offset (32) */
59 void *tcb_unused[3];
60 };
61
62 struct tls_dtv {
63 uintptr_t dtv_generation;
64 uintptr_t dtv_max_index;
65 void *dtv_offset[__ARRAY_ZERO];
66 };
67
68 /*
69 * NOTE: RTLD_STATIC_TLS_EXTRA_DEFAULT is set as the kernel's kern.tls_extra
70 * default, generally made large enough to accomodate modern libraries
71 * that desire to use static TLS sections. Make it roughly 2048 bytes
72 * smaller than a multiple of an aligned page for allocation efficiency.
73 */
74 #define RTLD_TCB_HAS_SELF_POINTER
75 #define RTLD_STATIC_TLS_ALIGN 16
76 #define RTLD_STATIC_TLS_ALIGN_MASK (RTLD_STATIC_TLS_ALIGN - 1)
77 #define RTLD_STATIC_TLS_EXTRA_MIN 2048
78 #define RTLD_STATIC_TLS_EXTRA_MAX (1*1024*1024*1024)
79 #define RTLD_STATIC_TLS_EXTRA_DEFAULT 6144 /* sysctl kern.tls_extra */
80 #define RTLD_STATIC_TLS_VARIANT_II
81
82 /* Get the current TCB. */
83 static __inline struct tls_tcb *
tls_get_tcb(void)84 tls_get_tcb(void)
85 {
86 void *self;
87
88 __asm __volatile ("movq %%fs:%1, %0"
89 : "=r" (self)
90 : "m" (((struct tls_tcb *)0)->tcb_self));
91
92 return(self);
93 }
94
95 /* Get the current thread. */
96 static __inline void *
tls_get_curthread(void)97 tls_get_curthread(void)
98 {
99 void *self;
100
101 __asm __volatile ("movq %%fs:%1, %0"
102 : "=r" (self)
103 : "m" (((struct tls_tcb *)0)->tcb_pthread));
104
105 return(self);
106 }
107
108 static __inline void
tls_set_tcb(struct tls_tcb * tcb)109 tls_set_tcb(struct tls_tcb *tcb)
110 {
111 struct tls_info info;
112 int seg;
113
114 info.base = tcb;
115 info.size = -1;
116 seg = set_tls_area(0, &info, sizeof(info));
117 /*__asm __volatile("movl %0, %%fs" : : "r" (seg));*/
118 }
119
120 static __inline void
tls_set_gs(void * base,size_t bytes)121 tls_set_gs(void *base, size_t bytes)
122 {
123 struct tls_info info;
124 int seg;
125
126 info.base = base;
127 info.size = bytes;
128 seg = set_tls_area(1, &info, sizeof(info));
129 /*__asm __volatile("mov %0, %%fs" : : "g" (seg));*/
130 }
131
132 #ifndef _KERNEL
133
134 struct tls_tcb *_rtld_allocate_tls(void);
135 struct tls_tcb *_libc_allocate_tls(void);
136 void _rtld_free_tls(struct tls_tcb *);
137 void _libc_free_tls(struct tls_tcb *);
138 void _rtld_call_init(void);
139 struct tls_tcb *_libc_init_tls(void);
140 struct tls_tcb *_init_tls(void);
141
142 #endif
143
144 #endif /* !_CPU_TLS_H_ */
145