1 /*- 2 * Copyright (c) 2006 Roman Divacky 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer 10 * in this position and unchanged. 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 * 3. The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include "opt_compat.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/imgact.h> 37 #include <sys/lock.h> 38 #include <sys/malloc.h> 39 #include <sys/mutex.h> 40 #include <sys/sx.h> 41 #include <sys/proc.h> 42 #include <sys/syscallsubr.h> 43 #include <sys/sysproto.h> 44 #include <sys/unistd.h> 45 46 #include <compat/linux/linux_emul.h> 47 #include <compat/linux/linux_futex.h> 48 49 #ifdef COMPAT_LINUX32 50 #include <machine/../linux32/linux.h> 51 #include <machine/../linux32/linux32_proto.h> 52 #else 53 #include <machine/../linux/linux.h> 54 #include <machine/../linux/linux_proto.h> 55 #endif 56 57 struct sx emul_shared_lock; 58 struct sx emul_lock; 59 60 /* this returns locked reference to the emuldata entry (if found) */ 61 struct linux_emuldata * 62 em_find(struct proc *p, int locked) 63 { 64 struct linux_emuldata *em; 65 66 if (locked == EMUL_DOLOCK) 67 EMUL_LOCK(&emul_lock); 68 69 em = p->p_emuldata; 70 71 if (em == NULL && locked == EMUL_DOLOCK) 72 EMUL_UNLOCK(&emul_lock); 73 74 return (em); 75 } 76 77 int 78 linux_proc_init(struct thread *td, pid_t child, int flags) 79 { 80 struct linux_emuldata *em, *p_em; 81 struct proc *p; 82 83 if (child != 0) { 84 /* non-exec call */ 85 em = malloc(sizeof *em, M_LINUX, M_WAITOK | M_ZERO); 86 em->pid = child; 87 em->pdeath_signal = 0; 88 if (flags & CLONE_THREAD) { 89 /* handled later in the code */ 90 } else { 91 struct linux_emuldata_shared *s; 92 93 s = malloc(sizeof *s, M_LINUX, M_WAITOK | M_ZERO); 94 em->shared = s; 95 s->refs = 1; 96 s->group_pid = child; 97 98 LIST_INIT(&s->threads); 99 } 100 p = pfind(child); 101 KASSERT(p != NULL, ("process not found in proc_init\n")); 102 p->p_emuldata = em; 103 PROC_UNLOCK(p); 104 EMUL_LOCK(&emul_lock); 105 } else { 106 /* lookup the old one */ 107 em = em_find(td->td_proc, EMUL_DOLOCK); 108 KASSERT(em != NULL, ("proc_init: emuldata not found in exec case.\n")); 109 } 110 111 em->child_clear_tid = NULL; 112 em->child_set_tid = NULL; 113 114 /* 115 * allocate the shared struct only in clone()/fork cases in the case 116 * of clone() td = calling proc and child = pid of the newly created 117 * proc 118 */ 119 if (child != 0) { 120 if (flags & CLONE_THREAD) { 121 /* lookup the parent */ 122 EMUL_SHARED_WLOCK(&emul_shared_lock); 123 p_em = em_find(td->td_proc, EMUL_DONTLOCK); 124 KASSERT(p_em != NULL, ("proc_init: parent emuldata not found for CLONE_THREAD\n")); 125 em->shared = p_em->shared; 126 em->shared->refs++; 127 EMUL_SHARED_WUNLOCK(&emul_shared_lock); 128 } else { 129 /* 130 * handled earlier to avoid malloc(M_WAITOK) with 131 * rwlock held 132 */ 133 } 134 } 135 if (child != 0) { 136 EMUL_UNLOCK(&emul_lock); 137 EMUL_SHARED_WLOCK(&emul_shared_lock); 138 LIST_INSERT_HEAD(&em->shared->threads, em, threads); 139 EMUL_SHARED_WUNLOCK(&emul_shared_lock); 140 141 p = pfind(child); 142 /* we might have a sleeping linux_schedtail */ 143 wakeup(&p->p_emuldata); 144 PROC_UNLOCK(p); 145 } else 146 EMUL_UNLOCK(&emul_lock); 147 148 return (0); 149 } 150 151 void 152 linux_proc_exit(void *arg __unused, struct proc *p) 153 { 154 struct linux_emuldata *em; 155 int error; 156 struct thread *td = FIRST_THREAD_IN_PROC(p); 157 int *child_clear_tid; 158 struct proc *q, *nq; 159 160 if (__predict_true(p->p_sysent != &elf_linux_sysvec)) 161 return; 162 163 /* find the emuldata */ 164 em = em_find(p, EMUL_DOLOCK); 165 166 KASSERT(em != NULL, ("proc_exit: emuldata not found.\n")); 167 168 child_clear_tid = em->child_clear_tid; 169 170 EMUL_UNLOCK(&emul_lock); 171 172 EMUL_SHARED_WLOCK(&emul_shared_lock); 173 LIST_REMOVE(em, threads); 174 175 PROC_LOCK(p); 176 p->p_emuldata = NULL; 177 PROC_UNLOCK(p); 178 179 em->shared->refs--; 180 if (em->shared->refs == 0) 181 free(em->shared, M_LINUX); 182 EMUL_SHARED_WUNLOCK(&emul_shared_lock); 183 184 if (child_clear_tid != NULL) { 185 struct linux_sys_futex_args cup; 186 int null = 0; 187 188 error = copyout(&null, child_clear_tid, sizeof(null)); 189 if (error) { 190 free(em, M_LINUX); 191 return; 192 } 193 194 /* futexes stuff */ 195 cup.uaddr = child_clear_tid; 196 cup.op = LINUX_FUTEX_WAKE; 197 cup.val = 0x7fffffff; /* Awake everyone */ 198 cup.timeout = NULL; 199 cup.uaddr2 = NULL; 200 cup.val3 = 0; 201 error = linux_sys_futex(FIRST_THREAD_IN_PROC(p), &cup); 202 /* 203 * this cannot happen at the moment and if this happens it 204 * probably mean there is a userspace bug 205 */ 206 if (error) 207 printf(LMSG("futex stuff in proc_exit failed.\n")); 208 } 209 210 /* clean the stuff up */ 211 free(em, M_LINUX); 212 213 /* this is a little weird but rewritten from exit1() */ 214 sx_xlock(&proctree_lock); 215 q = LIST_FIRST(&p->p_children); 216 for (; q != NULL; q = nq) { 217 nq = LIST_NEXT(q, p_sibling); 218 if (q->p_flag & P_WEXIT) 219 continue; 220 if (__predict_false(q->p_sysent != &elf_linux_sysvec)) 221 continue; 222 em = em_find(q, EMUL_DOLOCK); 223 KASSERT(em != NULL, ("linux_reparent: emuldata not found: %i\n", q->p_pid)); 224 if (em->pdeath_signal != 0) { 225 PROC_LOCK(q); 226 psignal(q, em->pdeath_signal); 227 PROC_UNLOCK(q); 228 } 229 EMUL_UNLOCK(&emul_lock); 230 } 231 sx_xunlock(&proctree_lock); 232 } 233 234 /* 235 * This is used in a case of transition from FreeBSD binary execing to linux binary 236 * in this case we create linux emuldata proc entry with the pid of the currently running 237 * process. 238 */ 239 void 240 linux_proc_exec(void *arg __unused, struct proc *p, struct image_params *imgp) 241 { 242 if (__predict_false(imgp->sysent == &elf_linux_sysvec 243 && p->p_sysent != &elf_linux_sysvec)) 244 linux_proc_init(FIRST_THREAD_IN_PROC(p), p->p_pid, 0); 245 if (__predict_false(imgp->sysent != &elf_linux_sysvec 246 && p->p_sysent == &elf_linux_sysvec)) { 247 struct linux_emuldata *em; 248 249 em = em_find(p, EMUL_DOLOCK); 250 251 KASSERT(em != NULL, ("proc_exec: emuldata not found.\n")); 252 253 EMUL_UNLOCK(&emul_lock); 254 255 EMUL_SHARED_WLOCK(&emul_shared_lock); 256 LIST_REMOVE(em, threads); 257 258 PROC_LOCK(p); 259 p->p_emuldata = NULL; 260 PROC_UNLOCK(p); 261 262 em->shared->refs--; 263 if (em->shared->refs == 0) 264 free(em->shared, M_LINUX); 265 EMUL_SHARED_WUNLOCK(&emul_shared_lock); 266 267 free(em, M_LINUX); 268 } 269 } 270 271 extern int hz; /* in subr_param.c */ 272 273 void 274 linux_schedtail(void *arg __unused, struct proc *p) 275 { 276 struct linux_emuldata *em; 277 int error = 0; 278 int *child_set_tid; 279 280 if (__predict_true(p->p_sysent != &elf_linux_sysvec)) 281 return; 282 283 retry: 284 /* find the emuldata */ 285 em = em_find(p, EMUL_DOLOCK); 286 287 if (em == NULL) { 288 /* 289 * We might have been called before proc_init for this 290 * process so tsleep and be woken up by it. We use 291 * p->p_emuldata for this 292 */ 293 294 error = tsleep(&p->p_emuldata, PLOCK, "linux_schedtail", hz); 295 if (error == 0) 296 goto retry; 297 panic("no emuldata found for userreting process.\n"); 298 } 299 child_set_tid = em->child_set_tid; 300 EMUL_UNLOCK(&emul_lock); 301 302 if (child_set_tid != NULL) 303 error = copyout(&p->p_pid, (int *)child_set_tid, 304 sizeof(p->p_pid)); 305 306 return; 307 } 308 309 int 310 linux_set_tid_address(struct thread *td, struct linux_set_tid_address_args *args) 311 { 312 struct linux_emuldata *em; 313 314 #ifdef DEBUG 315 if (ldebug(set_tid_address)) 316 printf(ARGS(set_tid_address, "%p"), args->tidptr); 317 #endif 318 319 /* find the emuldata */ 320 em = em_find(td->td_proc, EMUL_DOLOCK); 321 322 KASSERT(em != NULL, ("set_tid_address: emuldata not found.\n")); 323 324 em->child_clear_tid = args->tidptr; 325 td->td_retval[0] = td->td_proc->p_pid; 326 327 EMUL_UNLOCK(&emul_lock); 328 return 0; 329 } 330