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_VM) { 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 116 * in the case of clone() td = calling proc and child = pid of 117 * the newly created proc 118 */ 119 if (child != 0) { 120 if (flags & CLONE_VM) { 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_VM\n")); 124 em->shared = p_em->shared; 125 em->shared->refs++; 126 } else { 127 /* handled earlier to avoid malloc(M_WAITOK) with rwlock held */ 128 } 129 } 130 131 132 if (child != 0) { 133 EMUL_UNLOCK(&emul_lock); 134 EMUL_SHARED_WLOCK(&emul_shared_lock); 135 LIST_INSERT_HEAD(&em->shared->threads, em, threads); 136 EMUL_SHARED_WUNLOCK(&emul_shared_lock); 137 138 p = pfind(child); 139 /* we might have a sleeping linux_schedtail */ 140 wakeup(&p->p_emuldata); 141 PROC_UNLOCK(p); 142 } else 143 EMUL_UNLOCK(&emul_lock); 144 145 return (0); 146 } 147 148 void 149 linux_proc_exit(void *arg __unused, struct proc *p) 150 { 151 struct linux_emuldata *em; 152 int error; 153 struct thread *td = FIRST_THREAD_IN_PROC(p); 154 int *child_clear_tid; 155 struct proc *q, *nq; 156 157 if (__predict_true(p->p_sysent != &elf_linux_sysvec)) 158 return; 159 160 /* find the emuldata */ 161 em = em_find(p, EMUL_UNLOCKED); 162 163 KASSERT(em != NULL, ("proc_exit: emuldata not found.\n")); 164 165 child_clear_tid = em->child_clear_tid; 166 167 EMUL_UNLOCK(&emul_lock); 168 169 EMUL_SHARED_WLOCK(&emul_shared_lock); 170 LIST_REMOVE(em, threads); 171 172 PROC_LOCK(p); 173 p->p_emuldata = NULL; 174 PROC_UNLOCK(p); 175 176 em->shared->refs--; 177 if (em->shared->refs == 0) 178 free(em->shared, M_LINUX); 179 EMUL_SHARED_WUNLOCK(&emul_shared_lock); 180 181 if (child_clear_tid != NULL) { 182 struct linux_sys_futex_args cup; 183 int null = 0; 184 185 error = copyout(&null, child_clear_tid, sizeof(null)); 186 if (error) { 187 free(em, M_LINUX); 188 return; 189 } 190 191 /* futexes stuff */ 192 cup.uaddr = child_clear_tid; 193 cup.op = LINUX_FUTEX_WAKE; 194 cup.val = 0x7fffffff; /* Awake everyone */ 195 cup.timeout = NULL; 196 cup.uaddr2 = NULL; 197 cup.val3 = 0; 198 error = linux_sys_futex(FIRST_THREAD_IN_PROC(p), &cup); 199 /* 200 * this cannot happen at the moment and if this happens 201 * it probably mean there is a userspace bug 202 */ 203 if (error) 204 printf(LMSG("futex stuff in proc_exit failed.\n")); 205 } 206 207 /* clean the stuff up */ 208 free(em, M_LINUX); 209 210 /* this is a little weird but rewritten from exit1() */ 211 sx_xlock(&proctree_lock); 212 q = LIST_FIRST(&p->p_children); 213 for (; q != NULL; q = nq) { 214 nq = LIST_NEXT(q, p_sibling); 215 if (q->p_flag & P_WEXIT) 216 continue; 217 if (__predict_false(q->p_sysent != &elf_linux_sysvec)) 218 continue; 219 em = em_find(q, EMUL_UNLOCKED); 220 KASSERT(em != NULL, ("linux_reparent: emuldata not found: %i\n", q->p_pid)); 221 if (em->pdeath_signal != 0) { 222 PROC_LOCK(q); 223 psignal(q, em->pdeath_signal); 224 PROC_UNLOCK(q); 225 } 226 EMUL_UNLOCK(&emul_lock); 227 } 228 sx_xunlock(&proctree_lock); 229 } 230 231 /* 232 * This is used in a case of transition from FreeBSD binary execing to linux binary 233 * in this case we create linux emuldata proc entry with the pid of the currently running 234 * process. 235 */ 236 void linux_proc_exec(void *arg __unused, struct proc *p, struct image_params *imgp) 237 { 238 if (__predict_false(imgp->sysent == &elf_linux_sysvec 239 && p->p_sysent != &elf_linux_sysvec)) 240 linux_proc_init(FIRST_THREAD_IN_PROC(p), p->p_pid, 0); 241 if (__predict_false(imgp->sysent != &elf_linux_sysvec 242 && p->p_sysent == &elf_linux_sysvec)) { 243 struct linux_emuldata *em; 244 245 em = em_find(p, EMUL_UNLOCKED); 246 247 KASSERT(em != NULL, ("proc_exec: emuldata not found.\n")); 248 249 EMUL_UNLOCK(&emul_lock); 250 251 EMUL_SHARED_WLOCK(&emul_shared_lock); 252 LIST_REMOVE(em, threads); 253 254 PROC_LOCK(p); 255 p->p_emuldata = NULL; 256 PROC_UNLOCK(p); 257 258 em->shared->refs--; 259 if (em->shared->refs == 0) 260 free(em->shared, M_LINUX); 261 EMUL_SHARED_WUNLOCK(&emul_shared_lock); 262 263 free(em, M_LINUX); 264 } 265 } 266 267 extern int hz; /* in subr_param.c */ 268 269 void 270 linux_schedtail(void *arg __unused, struct proc *p) 271 { 272 struct linux_emuldata *em; 273 int error = 0; 274 int *child_set_tid; 275 276 if (__predict_true(p->p_sysent != &elf_linux_sysvec)) 277 return; 278 279 retry: 280 /* find the emuldata */ 281 em = em_find(p, EMUL_UNLOCKED); 282 283 if (em == NULL) { 284 /* 285 * We might have been called before proc_init for this process so 286 * tsleep and be woken up by it. We use p->p_emuldata for this 287 */ 288 289 error = tsleep(&p->p_emuldata, PLOCK, "linux_schedtail", hz); 290 if (error == 0) 291 goto retry; 292 panic("no emuldata found for userreting process.\n"); 293 } 294 child_set_tid = em->child_set_tid; 295 EMUL_UNLOCK(&emul_lock); 296 297 if (child_set_tid != NULL) 298 error = copyout(&p->p_pid, (int *) child_set_tid, sizeof(p->p_pid)); 299 300 return; 301 } 302 303 int 304 linux_set_tid_address(struct thread *td, struct linux_set_tid_address_args *args) 305 { 306 struct linux_emuldata *em; 307 308 #ifdef DEBUG 309 if (ldebug(set_tid_address)) 310 printf(ARGS(set_tid_address, "%p"), args->tidptr); 311 #endif 312 313 /* find the emuldata */ 314 em = em_find(td->td_proc, EMUL_UNLOCKED); 315 316 KASSERT(em != NULL, ("set_tid_address: emuldata not found.\n")); 317 318 em->child_clear_tid = args->tidptr; 319 td->td_retval[0] = td->td_proc->p_pid; 320 321 EMUL_UNLOCK(&emul_lock); 322 return 0; 323 } 324