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 * 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 * 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 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 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