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_UNLOCKED) 67 EMUL_LOCK(&emul_lock); 68 69 em = p->p_emuldata; 70 71 if (em == NULL && locked == EMUL_UNLOCKED) 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_UNLOCKED); 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 p_em = em_find(td->td_proc, EMUL_LOCKED); 123 KASSERT(p_em != NULL, ("proc_init: parent emuldata not found for CLONE_THREAD\n")); 124 em->shared = p_em->shared; 125 em->shared->refs++; 126 } else { 127 /* 128 * handled earlier to avoid malloc(M_WAITOK) with 129 * rwlock held 130 */ 131 } 132 } 133 if (child != 0) { 134 EMUL_UNLOCK(&emul_lock); 135 EMUL_SHARED_WLOCK(&emul_shared_lock); 136 LIST_INSERT_HEAD(&em->shared->threads, em, threads); 137 EMUL_SHARED_WUNLOCK(&emul_shared_lock); 138 139 p = pfind(child); 140 /* we might have a sleeping linux_schedtail */ 141 wakeup(&p->p_emuldata); 142 PROC_UNLOCK(p); 143 } else 144 EMUL_UNLOCK(&emul_lock); 145 146 return (0); 147 } 148 149 void 150 linux_proc_exit(void *arg __unused, struct proc *p) 151 { 152 struct linux_emuldata *em; 153 int error; 154 struct thread *td = FIRST_THREAD_IN_PROC(p); 155 int *child_clear_tid; 156 struct proc *q, *nq; 157 158 if (__predict_true(p->p_sysent != &elf_linux_sysvec)) 159 return; 160 161 /* find the emuldata */ 162 em = em_find(p, EMUL_UNLOCKED); 163 164 KASSERT(em != NULL, ("proc_exit: emuldata not found.\n")); 165 166 child_clear_tid = em->child_clear_tid; 167 168 EMUL_UNLOCK(&emul_lock); 169 170 EMUL_SHARED_WLOCK(&emul_shared_lock); 171 LIST_REMOVE(em, threads); 172 173 PROC_LOCK(p); 174 p->p_emuldata = NULL; 175 PROC_UNLOCK(p); 176 177 em->shared->refs--; 178 if (em->shared->refs == 0) 179 free(em->shared, M_LINUX); 180 EMUL_SHARED_WUNLOCK(&emul_shared_lock); 181 182 if (child_clear_tid != NULL) { 183 struct linux_sys_futex_args cup; 184 int null = 0; 185 186 error = copyout(&null, child_clear_tid, sizeof(null)); 187 if (error) { 188 free(em, M_LINUX); 189 return; 190 } 191 192 /* futexes stuff */ 193 cup.uaddr = child_clear_tid; 194 cup.op = LINUX_FUTEX_WAKE; 195 cup.val = 0x7fffffff; /* Awake everyone */ 196 cup.timeout = NULL; 197 cup.uaddr2 = NULL; 198 cup.val3 = 0; 199 error = linux_sys_futex(FIRST_THREAD_IN_PROC(p), &cup); 200 /* 201 * this cannot happen at the moment and if this happens it 202 * probably mean there is a userspace bug 203 */ 204 if (error) 205 printf(LMSG("futex stuff in proc_exit failed.\n")); 206 } 207 208 /* clean the stuff up */ 209 free(em, M_LINUX); 210 211 /* this is a little weird but rewritten from exit1() */ 212 sx_xlock(&proctree_lock); 213 q = LIST_FIRST(&p->p_children); 214 for (; q != NULL; q = nq) { 215 nq = LIST_NEXT(q, p_sibling); 216 if (q->p_flag & P_WEXIT) 217 continue; 218 if (__predict_false(q->p_sysent != &elf_linux_sysvec)) 219 continue; 220 em = em_find(q, EMUL_UNLOCKED); 221 KASSERT(em != NULL, ("linux_reparent: emuldata not found: %i\n", q->p_pid)); 222 if (em->pdeath_signal != 0) { 223 PROC_LOCK(q); 224 psignal(q, em->pdeath_signal); 225 PROC_UNLOCK(q); 226 } 227 EMUL_UNLOCK(&emul_lock); 228 } 229 sx_xunlock(&proctree_lock); 230 } 231 232 /* 233 * This is used in a case of transition from FreeBSD binary execing to linux binary 234 * in this case we create linux emuldata proc entry with the pid of the currently running 235 * process. 236 */ 237 void 238 linux_proc_exec(void *arg __unused, struct proc *p, struct image_params *imgp) 239 { 240 if (__predict_false(imgp->sysent == &elf_linux_sysvec 241 && p->p_sysent != &elf_linux_sysvec)) 242 linux_proc_init(FIRST_THREAD_IN_PROC(p), p->p_pid, 0); 243 if (__predict_false(imgp->sysent != &elf_linux_sysvec 244 && p->p_sysent == &elf_linux_sysvec)) { 245 struct linux_emuldata *em; 246 247 em = em_find(p, EMUL_UNLOCKED); 248 249 KASSERT(em != NULL, ("proc_exec: emuldata not found.\n")); 250 251 EMUL_UNLOCK(&emul_lock); 252 253 EMUL_SHARED_WLOCK(&emul_shared_lock); 254 LIST_REMOVE(em, threads); 255 256 PROC_LOCK(p); 257 p->p_emuldata = NULL; 258 PROC_UNLOCK(p); 259 260 em->shared->refs--; 261 if (em->shared->refs == 0) 262 free(em->shared, M_LINUX); 263 EMUL_SHARED_WUNLOCK(&emul_shared_lock); 264 265 free(em, M_LINUX); 266 } 267 } 268 269 extern int hz; /* in subr_param.c */ 270 271 void 272 linux_schedtail(void *arg __unused, struct proc *p) 273 { 274 struct linux_emuldata *em; 275 int error = 0; 276 int *child_set_tid; 277 278 if (__predict_true(p->p_sysent != &elf_linux_sysvec)) 279 return; 280 281 retry: 282 /* find the emuldata */ 283 em = em_find(p, EMUL_UNLOCKED); 284 285 if (em == NULL) { 286 /* 287 * We might have been called before proc_init for this 288 * process so tsleep and be woken up by it. We use 289 * p->p_emuldata for this 290 */ 291 292 error = tsleep(&p->p_emuldata, PLOCK, "linux_schedtail", hz); 293 if (error == 0) 294 goto retry; 295 panic("no emuldata found for userreting process.\n"); 296 } 297 child_set_tid = em->child_set_tid; 298 EMUL_UNLOCK(&emul_lock); 299 300 if (child_set_tid != NULL) 301 error = copyout(&p->p_pid, (int *)child_set_tid, 302 sizeof(p->p_pid)); 303 304 return; 305 } 306 307 int 308 linux_set_tid_address(struct thread *td, struct linux_set_tid_address_args *args) 309 { 310 struct linux_emuldata *em; 311 312 #ifdef DEBUG 313 if (ldebug(set_tid_address)) 314 printf(ARGS(set_tid_address, "%p"), args->tidptr); 315 #endif 316 317 /* find the emuldata */ 318 em = em_find(td->td_proc, EMUL_UNLOCKED); 319 320 KASSERT(em != NULL, ("set_tid_address: emuldata not found.\n")); 321 322 em->child_clear_tid = args->tidptr; 323 td->td_retval[0] = td->td_proc->p_pid; 324 325 EMUL_UNLOCK(&emul_lock); 326 return 0; 327 } 328