1 /* 2 * Copyright (c) 2003,2004,2008 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by David Xu <davidxu@t2t2.com> and Matthew Dillon <dillon@backplane.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 */ 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/sysproto.h> 39 #include <sys/kernel.h> 40 #include <sys/proc.h> 41 #include <sys/sysent.h> 42 #include <sys/sysctl.h> 43 #include <sys/tls.h> 44 #include <sys/reg.h> 45 #include <sys/globaldata.h> 46 47 #include <sys/thread2.h> 48 49 #include <machine/cpu.h> 50 #include <machine/clock.h> 51 #include <machine/specialreg.h> 52 #include <machine/segments.h> 53 #include <machine/md_var.h> 54 #include <machine/pcb_ext.h> /* pcb.h included via sys/user.h */ 55 #include <machine/globaldata.h> /* CPU_prvspace */ 56 #include <machine/smp.h> 57 #include <machine/pcb.h> 58 59 /* 60 * set a TLS descriptor. For x86_64 descriptor 0 identifies %fs and 61 * descriptor 1 identifies %gs, and 0 is returned in sysmsg_result. 62 * 63 * Returns the value userland needs to load into %gs representing the 64 * TLS descriptor or -1 on error. 65 * 66 * (int which, struct tls_info *info, size_t infosize) 67 */ 68 int 69 sys_set_tls_area(struct set_tls_area_args *uap) 70 { 71 struct tls_info info; 72 int error; 73 int i; 74 75 /* 76 * Sanity checks 77 * 78 * which 0 == %fs, which 1 == %gs 79 */ 80 i = uap->which; 81 if (i < 0 || i > 1) 82 return (ERANGE); 83 if (uap->infosize < 0) 84 return (EINVAL); 85 86 /* 87 * Maintain forwards compatibility with future extensions. 88 */ 89 if (uap->infosize != sizeof(info)) { 90 bzero(&info, sizeof(info)); 91 error = copyin(uap->info, &info, 92 min(sizeof(info), uap->infosize)); 93 } else { 94 error = copyin(uap->info, &info, sizeof(info)); 95 } 96 if (error) 97 return (error); 98 if (info.size < -1) 99 return (EINVAL); 100 101 /* 102 * For x86_64 we can only adjust FSBASE and GSBASE 103 */ 104 curthread->td_tls.info[i] = info; 105 set_user_TLS(); 106 uap->sysmsg_result = 0; /* segment descriptor $0 */ 107 return(0); 108 } 109 110 /* 111 * Return the specified TLS descriptor to userland. 112 * 113 * Returns the value userland needs to load into %gs representing the 114 * TLS descriptor or -1 on error. 115 * 116 * (int which, struct tls_info *info, size_t infosize) 117 */ 118 int 119 sys_get_tls_area(struct get_tls_area_args *uap) 120 { 121 struct tls_info info; 122 int error; 123 int i; 124 125 /* 126 * Sanity checks 127 */ 128 i = uap->which; 129 if (i < 0 || i > 1) 130 return (ERANGE); 131 if (uap->infosize < 0) 132 return (EINVAL); 133 134 info = curthread->td_tls.info[i]; 135 136 error = copyout(&info, uap->info, min(sizeof(info), uap->infosize)); 137 return(error); 138 } 139 140 /* 141 * This function is a NOP because the TLS segments are proactively copied 142 * by vmspace_ctl() when we switch to the (emulated) user process. 143 */ 144 void 145 set_user_TLS(void) 146 { 147 } 148