linux_exec_machdep.c revision 1.10
1 /* $NetBSD: linux_exec_machdep.c,v 1.10 2008/10/26 17:57:49 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2004 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: linux_exec_machdep.c,v 1.10 2008/10/26 17:57:49 christos Exp $"); 34 35 #if defined(_KERNEL_OPT) 36 #include "opt_vm86.h" 37 #include "opt_user_ldt.h" 38 #endif 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/resource.h> 43 #include <sys/proc.h> 44 #include <sys/conf.h> 45 #include <sys/exec.h> 46 #include <sys/exec_elf.h> 47 #include <sys/vnode.h> 48 #include <sys/lwp.h> 49 50 #include <sys/cpu.h> 51 #include <machine/vmparam.h> 52 53 #include <uvm/uvm.h> 54 55 #include <sys/syscallargs.h> 56 57 #ifndef DEBUG_LINUX 58 #define DPRINTF(a) 59 #else 60 #define DPRINTF(a) uprintf a 61 #endif 62 63 #include <compat/linux/common/linux_types.h> 64 #include <compat/linux/common/linux_signal.h> 65 #include <compat/linux/common/linux_machdep.h> 66 #include <compat/linux/common/linux_util.h> 67 #include <compat/linux/common/linux_ioctl.h> 68 #include <compat/linux/common/linux_hdio.h> 69 #include <compat/linux/common/linux_exec.h> 70 #include <compat/linux/common/linux_errno.h> 71 #include <compat/linux//linux_syscallargs.h> 72 73 74 int 75 linux_exec_setup_stack(struct lwp *l, struct exec_package *epp) 76 { 77 u_long max_stack_size; 78 u_long access_linear_min, access_size; 79 u_long noaccess_linear_min, noaccess_size; 80 81 #ifndef USRSTACK32 82 #define USRSTACK32 (0x00000000ffffffffL&~PGOFSET) 83 #endif 84 85 if (epp->ep_flags & EXEC_32) { 86 epp->ep_minsaddr = USRSTACK32; 87 max_stack_size = MAXSSIZ; 88 } else { 89 epp->ep_minsaddr = USRSTACK; 90 max_stack_size = MAXSSIZ; 91 } 92 93 if (epp->ep_minsaddr > LINUX_USRSTACK) 94 epp->ep_minsaddr = LINUX_USRSTACK; 95 #ifdef DEBUG_LINUX 96 else { 97 /* 98 * Someone needs to make KERNBASE and TEXTADDR 99 * java versions < 1.4.2 need the stack to be 100 * at 0xC0000000 101 */ 102 uprintf("Cannot setup stack to 0xC0000000, " 103 "java will not work properly\n"); 104 } 105 #endif 106 epp->ep_maxsaddr = (u_long)STACK_GROW(epp->ep_minsaddr, 107 max_stack_size); 108 epp->ep_ssize = l->l_proc->p_rlimit[RLIMIT_STACK].rlim_cur; 109 110 /* 111 * set up commands for stack. note that this takes *two*, one to 112 * map the part of the stack which we can access, and one to map 113 * the part which we can't. 114 * 115 * arguably, it could be made into one, but that would require the 116 * addition of another mapping proc, which is unnecessary 117 */ 118 access_size = epp->ep_ssize; 119 access_linear_min = (u_long)STACK_ALLOC(epp->ep_minsaddr, access_size); 120 noaccess_size = max_stack_size - access_size; 121 noaccess_linear_min = (u_long)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr, 122 access_size), noaccess_size); 123 if (noaccess_size > 0) { 124 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, noaccess_size, 125 noaccess_linear_min, NULLVP, 0, VM_PROT_NONE); 126 } 127 KASSERT(access_size > 0); 128 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, access_size, 129 access_linear_min, NULLVP, 0, VM_PROT_READ | VM_PROT_WRITE); 130 131 return 0; 132 } 133 134 135 #ifdef LINUX_NPTL 136 static __inline void 137 load_gs(u_int sel) 138 { 139 __asm __volatile("movl %0,%%gs" : : "rm" (sel)); 140 } 141 142 143 int 144 linux_init_thread_area(struct lwp *l, struct lwp *l2) 145 { 146 struct trapframe *tf = l->l_md.md_regs, *tf2 = l2->l_md.md_regs; 147 struct pcb *pcb2 = &l2->l_addr->u_pcb; 148 struct linux_user_desc info; 149 struct segment_descriptor sd; 150 int error, idx, a[2]; 151 152 error = copyin((void *)tf->tf_esi, &info, sizeof(info)); 153 if (error) 154 return error; 155 idx = info.entry_number; 156 157 /* 158 * looks like we're getting the idx we returned 159 * in the set_thread_area() syscall 160 */ 161 if (idx != LINUX_GLIBC_TLS_SEL && idx != GUGS_SEL) { 162 DPRINTF(("resetting idx %d to GUGS_SEL", idx)); 163 idx = GUGS_SEL; 164 } 165 166 /* this doesnt happen in practice */ 167 if (idx == LINUX_GLIBC_TLS_SEL) { 168 /* we might copy out the entry_number as 3 */ 169 info.entry_number = GUGS_SEL; 170 error = copyout(&info, (void *)tf->tf_esi, sizeof(info)); 171 if (error) 172 return error; 173 } 174 175 a[0] = LINUX_LDT_entry_a(&info); 176 a[1] = LINUX_LDT_entry_b(&info); 177 178 (void)memcpy(&sd, &a, sizeof(a)); 179 KASSERT(ISMEMSDP((&sd))); 180 DPRINTF(("Segment created in clone with CLONE_SETTLS: lobase: %x, " 181 "hibase: %x, lolimit: %x, hilimit: %x, type: %i, dpl: %i, p: %i, " 182 "xx: %i, def32: %i, gran: %i\n", sd.sd_lobase, 183 sd.sd_hibase, sd.sd_lolimit, sd.sd_hilimit, sd.sd_type, sd.sd_dpl, 184 sd.sd_p, sd.sd_xx, sd.sd_def32, sd.sd_gran)); 185 186 kpreempt_disable(); 187 (void)memcpy(&pcb2->pcb_gsd, &sd, sizeof(sd)); 188 (void)memcpy(&curcpu()->ci_gdt[GUGS_SEL], &sd, sizeof(sd)); 189 tf2->tf_gs = GSEL(GUGS_SEL, SEL_UPL); 190 load_gs(tf2->tf_gs); 191 kpreempt_enable(); 192 return 0; 193 } 194 195 196 int 197 linux_sys_set_thread_area(struct lwp *l, 198 const struct linux_sys_set_thread_area_args *uap, register_t *retval) 199 { 200 struct trapframe *tf = l->l_md.md_regs; 201 struct pcb *pcb = &l->l_addr->u_pcb; 202 struct linux_user_desc info; 203 struct segment_descriptor sd; 204 int error, idx, a[2]; 205 206 *retval = 0; 207 error = copyin(SCARG(uap, desc), &info, sizeof(info)); 208 if (error) 209 return error; 210 211 DPRINTF(("set thread area: %i, %x, %x, %i, %i, %i, %i, %i, %i\n", 212 info.entry_number, info.base_addr, info.limit, info.seg_32bit, 213 info.contents, info.read_exec_only, info.limit_in_pages, 214 info.seg_not_present, info.useable)); 215 216 idx = info.entry_number; 217 /* 218 * Semantics of linux version: every thread in the system has array of 219 * 3 tls descriptors. 1st is GLIBC TLS, 2nd is WINE, 3rd unknown. This 220 * syscall loads one of the selected tls decriptors with a value and 221 * also loads GDT descriptors 6, 7 and 8 with the content of the 222 * per-thread descriptors. 223 * 224 * Semantics of fbsd version: I think we can ignore that linux has 3 225 * per-thread descriptors and use just the 1st one. The tls_array[] 226 * is used only in set/get-thread_area() syscalls and for loading the 227 * GDT descriptors. In fbsd we use just one GDT descriptor for TLS so 228 * we will load just one. 229 * 230 * XXX: this doesn't work when a user space process tries to use more 231 * than 1 TLS segment. Comment in the linux sources says wine might do 232 * this. 233 */ 234 235 /* 236 * we support just GLIBC TLS now 237 * we should let 3 proceed as well because we use this segment so 238 * if code does two subsequent calls it should succeed 239 */ 240 if (idx != LINUX_GLIBC_TLS_SEL && idx != -1 && idx != GUGS_SEL) 241 return EINVAL; 242 243 /* 244 * we have to copy out the GDT entry we use 245 * FreeBSD uses GDT entry #3 for storing %gs so load that 246 * 247 * XXX: what if a user space program doesn't check this value and tries 248 * to use 6, 7 or 8? 249 */ 250 idx = info.entry_number = GUGS_SEL; 251 error = copyout(&info, SCARG(uap, desc), sizeof(info)); 252 if (error) 253 return error; 254 255 if (LINUX_LDT_empty(&info)) { 256 a[0] = 0; 257 a[1] = 0; 258 } else { 259 a[0] = LINUX_LDT_entry_a(&info); 260 a[1] = LINUX_LDT_entry_b(&info); 261 } 262 263 (void)memcpy(&sd, &a, sizeof(a)); 264 KASSERT(ISMEMSDP((&sd))); 265 DPRINTF(("Segment created in set_thread_area: lobase: %x, hibase: %x, " 266 "lolimit: %x, hilimit: %x, type: %i, dpl: %i, p: %i, xx: %i, " 267 "def32: %i, gran: %i\n", sd.sd_lobase, sd.sd_hibase, sd.sd_lolimit, 268 sd.sd_hilimit, sd.sd_type, sd.sd_dpl, sd.sd_p, sd.sd_xx, 269 sd.sd_def32, sd.sd_gran)); 270 271 kpreempt_disable(); 272 (void)memcpy(&pcb->pcb_gsd, &sd, sizeof(sd)); 273 (void)memcpy(&curcpu()->ci_gdt[GUGS_SEL], &sd, sizeof(sd)); 274 tf->tf_gs = GSEL(GUGS_SEL, SEL_UPL); 275 load_gs(tf->tf_gs); 276 kpreempt_enable(); 277 return 0; 278 } 279 280 int 281 linux_sys_get_thread_area(struct lwp *l, 282 const struct linux_sys_get_thread_area_args *uap, register_t *retval) 283 { 284 struct pcb *pcb = &l->l_addr->u_pcb; 285 struct linux_user_desc info; 286 struct linux_desc_struct desc; 287 struct segment_descriptor sd; 288 int error, idx; 289 290 *retval = 0; 291 error = copyin(SCARG(uap, desc), &info, sizeof(info)); 292 if (error) 293 return error; 294 295 idx = info.entry_number; 296 /* XXX: I am not sure if we want 3 to be allowed too. */ 297 if (idx != LINUX_GLIBC_TLS_SEL && idx != GUGS_SEL) 298 return EINVAL; 299 300 idx = GUGS_SEL; 301 302 (void)memset(&info, 0, sizeof(info)); 303 (void)memcpy(&sd, pcb->pcb_gsd, sizeof(sd)); 304 (void)memcpy(&desc, &sd, sizeof(desc)); 305 306 info.entry_number = idx; 307 info.base_addr = LINUX_GET_BASE(&desc); 308 info.limit = LINUX_GET_LIMIT(&desc); 309 info.seg_32bit = LINUX_GET_32BIT(&desc); 310 info.contents = LINUX_GET_CONTENTS(&desc); 311 info.read_exec_only = !LINUX_GET_WRITABLE(&desc); 312 info.limit_in_pages = LINUX_GET_LIMIT_PAGES(&desc); 313 info.seg_not_present = !LINUX_GET_PRESENT(&desc); 314 info.useable = LINUX_GET_USEABLE(&desc); 315 316 return copyout(&info, SCARG(uap, desc), sizeof(info)); 317 } 318 319 #endif 320
Indexes created Tue Sep 30 07:10:03 GMT 2025