Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/kernel/exit.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 7 | #include <linux/mm.h> |
| 8 | #include <linux/slab.h> |
| 9 | #include <linux/interrupt.h> |
| 10 | #include <linux/smp_lock.h> |
| 11 | #include <linux/module.h> |
Randy.Dunlap | c59ede7 | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 12 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/completion.h> |
| 14 | #include <linux/personality.h> |
| 15 | #include <linux/tty.h> |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 16 | #include <linux/mnt_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/key.h> |
| 18 | #include <linux/security.h> |
| 19 | #include <linux/cpu.h> |
| 20 | #include <linux/acct.h> |
Jay Lan | 8f0ab51 | 2006-09-30 23:28:59 -0700 | [diff] [blame] | 21 | #include <linux/tsacct_kern.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <linux/file.h> |
| 23 | #include <linux/binfmts.h> |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 24 | #include <linux/nsproxy.h> |
Sukadev Bhattiprolu | 84d7378 | 2006-12-08 02:38:01 -0800 | [diff] [blame] | 25 | #include <linux/pid_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | #include <linux/ptrace.h> |
| 27 | #include <linux/profile.h> |
| 28 | #include <linux/mount.h> |
| 29 | #include <linux/proc_fs.h> |
| 30 | #include <linux/mempolicy.h> |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 31 | #include <linux/taskstats_kern.h> |
Shailabh Nagar | ca74e92 | 2006-07-14 00:24:36 -0700 | [diff] [blame] | 32 | #include <linux/delayacct.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | #include <linux/cpuset.h> |
| 34 | #include <linux/syscalls.h> |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 35 | #include <linux/signal.h> |
Oleg Nesterov | 6a14c5c | 2006-03-28 16:11:18 -0800 | [diff] [blame] | 36 | #include <linux/posix-timers.h> |
Matt Helsley | 9f46080 | 2005-11-07 00:59:16 -0800 | [diff] [blame] | 37 | #include <linux/cn_proc.h> |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 38 | #include <linux/mutex.h> |
Ingo Molnar | 0771dfe | 2006-03-27 01:16:22 -0800 | [diff] [blame] | 39 | #include <linux/futex.h> |
Ingo Molnar | 34f192c | 2006-03-27 01:16:24 -0800 | [diff] [blame] | 40 | #include <linux/compat.h> |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 41 | #include <linux/pipe_fs_i.h> |
Al Viro | fa84cb9 | 2006-03-29 20:30:19 -0500 | [diff] [blame] | 42 | #include <linux/audit.h> /* for audit_free() */ |
Adrian Bunk | 83cc5ed | 2006-06-25 05:47:41 -0700 | [diff] [blame] | 43 | #include <linux/resource.h> |
David Howells | 0d67a46 | 2006-08-29 19:05:56 +0100 | [diff] [blame] | 44 | #include <linux/blkdev.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | |
| 46 | #include <asm/uaccess.h> |
| 47 | #include <asm/unistd.h> |
| 48 | #include <asm/pgtable.h> |
| 49 | #include <asm/mmu_context.h> |
| 50 | |
| 51 | extern void sem_exit (void); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | |
Adrian Bunk | 408b664 | 2005-05-01 08:59:29 -0700 | [diff] [blame] | 53 | static void exit_mm(struct task_struct * tsk); |
| 54 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | static void __unhash_process(struct task_struct *p) |
| 56 | { |
| 57 | nr_threads--; |
| 58 | detach_pid(p, PIDTYPE_PID); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | if (thread_group_leader(p)) { |
| 60 | detach_pid(p, PIDTYPE_PGID); |
| 61 | detach_pid(p, PIDTYPE_SID); |
Oleg Nesterov | c97d989 | 2006-03-28 16:11:06 -0800 | [diff] [blame] | 62 | |
Eric W. Biederman | 5e85d4a | 2006-04-18 22:20:16 -0700 | [diff] [blame] | 63 | list_del_rcu(&p->tasks); |
Oleg Nesterov | 73b9ebf | 2006-03-28 16:11:07 -0800 | [diff] [blame] | 64 | __get_cpu_var(process_counts)--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | } |
Oleg Nesterov | 47e6532 | 2006-03-28 16:11:25 -0800 | [diff] [blame] | 66 | list_del_rcu(&p->thread_group); |
Oleg Nesterov | c97d989 | 2006-03-28 16:11:06 -0800 | [diff] [blame] | 67 | remove_parent(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | } |
| 69 | |
Oleg Nesterov | 6a14c5c | 2006-03-28 16:11:18 -0800 | [diff] [blame] | 70 | /* |
| 71 | * This function expects the tasklist_lock write-locked. |
| 72 | */ |
| 73 | static void __exit_signal(struct task_struct *tsk) |
| 74 | { |
| 75 | struct signal_struct *sig = tsk->signal; |
| 76 | struct sighand_struct *sighand; |
| 77 | |
| 78 | BUG_ON(!sig); |
| 79 | BUG_ON(!atomic_read(&sig->count)); |
| 80 | |
| 81 | rcu_read_lock(); |
| 82 | sighand = rcu_dereference(tsk->sighand); |
| 83 | spin_lock(&sighand->siglock); |
| 84 | |
| 85 | posix_cpu_timers_exit(tsk); |
| 86 | if (atomic_dec_and_test(&sig->count)) |
| 87 | posix_cpu_timers_exit_group(tsk); |
| 88 | else { |
| 89 | /* |
| 90 | * If there is any task waiting for the group exit |
| 91 | * then notify it: |
| 92 | */ |
| 93 | if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count) { |
| 94 | wake_up_process(sig->group_exit_task); |
| 95 | sig->group_exit_task = NULL; |
| 96 | } |
| 97 | if (tsk == sig->curr_target) |
| 98 | sig->curr_target = next_thread(tsk); |
| 99 | /* |
| 100 | * Accumulate here the counters for all threads but the |
| 101 | * group leader as they die, so they can be added into |
| 102 | * the process-wide totals when those are taken. |
| 103 | * The group leader stays around as a zombie as long |
| 104 | * as there are other threads. When it gets reaped, |
| 105 | * the exit.c code will add its counts into these totals. |
| 106 | * We won't ever get here for the group leader, since it |
| 107 | * will have been the last reference on the signal_struct. |
| 108 | */ |
| 109 | sig->utime = cputime_add(sig->utime, tsk->utime); |
| 110 | sig->stime = cputime_add(sig->stime, tsk->stime); |
| 111 | sig->min_flt += tsk->min_flt; |
| 112 | sig->maj_flt += tsk->maj_flt; |
| 113 | sig->nvcsw += tsk->nvcsw; |
| 114 | sig->nivcsw += tsk->nivcsw; |
| 115 | sig->sched_time += tsk->sched_time; |
| 116 | sig = NULL; /* Marker for below. */ |
| 117 | } |
| 118 | |
Oleg Nesterov | 5876700 | 2006-03-28 16:11:20 -0800 | [diff] [blame] | 119 | __unhash_process(tsk); |
| 120 | |
Oleg Nesterov | 6a14c5c | 2006-03-28 16:11:18 -0800 | [diff] [blame] | 121 | tsk->signal = NULL; |
Oleg Nesterov | a7e5328 | 2006-03-28 16:11:27 -0800 | [diff] [blame] | 122 | tsk->sighand = NULL; |
Oleg Nesterov | 6a14c5c | 2006-03-28 16:11:18 -0800 | [diff] [blame] | 123 | spin_unlock(&sighand->siglock); |
| 124 | rcu_read_unlock(); |
| 125 | |
Oleg Nesterov | a7e5328 | 2006-03-28 16:11:27 -0800 | [diff] [blame] | 126 | __cleanup_sighand(sighand); |
Oleg Nesterov | 6a14c5c | 2006-03-28 16:11:18 -0800 | [diff] [blame] | 127 | clear_tsk_thread_flag(tsk,TIF_SIGPENDING); |
| 128 | flush_sigqueue(&tsk->pending); |
| 129 | if (sig) { |
| 130 | flush_sigqueue(&sig->shared_pending); |
Oleg Nesterov | 093a8e8 | 2006-10-28 10:38:51 -0700 | [diff] [blame] | 131 | taskstats_tgid_free(sig); |
Oleg Nesterov | 6a14c5c | 2006-03-28 16:11:18 -0800 | [diff] [blame] | 132 | __cleanup_signal(sig); |
| 133 | } |
| 134 | } |
| 135 | |
Eric W. Biederman | 8c7904a | 2006-03-31 02:31:37 -0800 | [diff] [blame] | 136 | static void delayed_put_task_struct(struct rcu_head *rhp) |
| 137 | { |
| 138 | put_task_struct(container_of(rhp, struct task_struct, rcu)); |
| 139 | } |
| 140 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | void release_task(struct task_struct * p) |
| 142 | { |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 143 | struct task_struct *leader; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | int zap_leader; |
Oleg Nesterov | 1f09f97 | 2006-03-28 16:11:11 -0800 | [diff] [blame] | 145 | repeat: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | atomic_dec(&p->user->processes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | write_lock_irq(&tasklist_lock); |
Oleg Nesterov | 1f09f97 | 2006-03-28 16:11:11 -0800 | [diff] [blame] | 148 | ptrace_unlink(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children)); |
| 150 | __exit_signal(p); |
Oleg Nesterov | 35f5cad | 2006-03-28 16:11:19 -0800 | [diff] [blame] | 151 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | /* |
| 153 | * If we are the last non-leader member of the thread |
| 154 | * group, and the leader is zombie, then notify the |
| 155 | * group leader's parent process. (if it wants notification.) |
| 156 | */ |
| 157 | zap_leader = 0; |
| 158 | leader = p->group_leader; |
| 159 | if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) { |
| 160 | BUG_ON(leader->exit_signal == -1); |
| 161 | do_notify_parent(leader, leader->exit_signal); |
| 162 | /* |
| 163 | * If we were the last child thread and the leader has |
| 164 | * exited already, and the leader's parent ignores SIGCHLD, |
| 165 | * then we are the one who should release the leader. |
| 166 | * |
| 167 | * do_notify_parent() will have marked it self-reaping in |
| 168 | * that case. |
| 169 | */ |
| 170 | zap_leader = (leader->exit_signal == -1); |
| 171 | } |
| 172 | |
| 173 | sched_exit(p); |
| 174 | write_unlock_irq(&tasklist_lock); |
Eric W. Biederman | 48e6484 | 2006-06-26 00:25:48 -0700 | [diff] [blame] | 175 | proc_flush_task(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | release_thread(p); |
Eric W. Biederman | 8c7904a | 2006-03-31 02:31:37 -0800 | [diff] [blame] | 177 | call_rcu(&p->rcu, delayed_put_task_struct); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | |
| 179 | p = leader; |
| 180 | if (unlikely(zap_leader)) |
| 181 | goto repeat; |
| 182 | } |
| 183 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | /* |
| 185 | * This checks not only the pgrp, but falls back on the pid if no |
| 186 | * satisfactory pgrp is found. I dunno - gdb doesn't work correctly |
| 187 | * without this... |
Eric W. Biederman | 04a2e6a | 2007-02-12 00:52:56 -0800 | [diff] [blame^] | 188 | * |
| 189 | * The caller must hold rcu lock or the tasklist lock. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | */ |
Eric W. Biederman | 04a2e6a | 2007-02-12 00:52:56 -0800 | [diff] [blame^] | 191 | struct pid *session_of_pgrp(struct pid *pgrp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | { |
| 193 | struct task_struct *p; |
Eric W. Biederman | 04a2e6a | 2007-02-12 00:52:56 -0800 | [diff] [blame^] | 194 | struct pid *sid = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | |
Eric W. Biederman | 04a2e6a | 2007-02-12 00:52:56 -0800 | [diff] [blame^] | 196 | p = pid_task(pgrp, PIDTYPE_PGID); |
Oleg Nesterov | 62dfb55 | 2006-12-08 02:38:03 -0800 | [diff] [blame] | 197 | if (p == NULL) |
Eric W. Biederman | 04a2e6a | 2007-02-12 00:52:56 -0800 | [diff] [blame^] | 198 | p = pid_task(pgrp, PIDTYPE_PID); |
Oleg Nesterov | 62dfb55 | 2006-12-08 02:38:03 -0800 | [diff] [blame] | 199 | if (p != NULL) |
Eric W. Biederman | 04a2e6a | 2007-02-12 00:52:56 -0800 | [diff] [blame^] | 200 | sid = task_session(p); |
Oleg Nesterov | 62dfb55 | 2006-12-08 02:38:03 -0800 | [diff] [blame] | 201 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | return sid; |
| 203 | } |
| 204 | |
| 205 | /* |
| 206 | * Determine if a process group is "orphaned", according to the POSIX |
| 207 | * definition in 2.2.2.52. Orphaned process groups are not to be affected |
| 208 | * by terminal-generated stop signals. Newly orphaned process groups are |
| 209 | * to receive a SIGHUP and a SIGCONT. |
| 210 | * |
| 211 | * "I ask you, have you ever known what it is to be an orphan?" |
| 212 | */ |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 213 | static int will_become_orphaned_pgrp(int pgrp, struct task_struct *ignored_task) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | { |
| 215 | struct task_struct *p; |
| 216 | int ret = 1; |
| 217 | |
| 218 | do_each_task_pid(pgrp, PIDTYPE_PGID, p) { |
| 219 | if (p == ignored_task |
| 220 | || p->exit_state |
Sukadev Bhattiprolu | f400e19 | 2006-09-29 02:00:07 -0700 | [diff] [blame] | 221 | || is_init(p->real_parent)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | continue; |
Cedric Le Goater | 937949d | 2006-12-08 02:37:54 -0800 | [diff] [blame] | 223 | if (process_group(p->real_parent) != pgrp && |
| 224 | process_session(p->real_parent) == process_session(p)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | ret = 0; |
| 226 | break; |
| 227 | } |
| 228 | } while_each_task_pid(pgrp, PIDTYPE_PGID, p); |
| 229 | return ret; /* (sighing) "Often!" */ |
| 230 | } |
| 231 | |
| 232 | int is_orphaned_pgrp(int pgrp) |
| 233 | { |
| 234 | int retval; |
| 235 | |
| 236 | read_lock(&tasklist_lock); |
| 237 | retval = will_become_orphaned_pgrp(pgrp, NULL); |
| 238 | read_unlock(&tasklist_lock); |
| 239 | |
| 240 | return retval; |
| 241 | } |
| 242 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 243 | static int has_stopped_jobs(int pgrp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 244 | { |
| 245 | int retval = 0; |
| 246 | struct task_struct *p; |
| 247 | |
| 248 | do_each_task_pid(pgrp, PIDTYPE_PGID, p) { |
| 249 | if (p->state != TASK_STOPPED) |
| 250 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | retval = 1; |
| 252 | break; |
| 253 | } while_each_task_pid(pgrp, PIDTYPE_PGID, p); |
| 254 | return retval; |
| 255 | } |
| 256 | |
| 257 | /** |
Robert P. J. Day | 72fd4a3 | 2007-02-10 01:45:59 -0800 | [diff] [blame] | 258 | * reparent_to_init - Reparent the calling kernel thread to the init task of the pid space that the thread belongs to. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | * |
| 260 | * If a kernel thread is launched as a result of a system call, or if |
| 261 | * it ever exits, it should generally reparent itself to init so that |
| 262 | * it is correctly cleaned up on exit. |
| 263 | * |
| 264 | * The various task state such as scheduling policy and priority may have |
| 265 | * been inherited from a user process, so we reset them to sane values here. |
| 266 | * |
| 267 | * NOTE that reparent_to_init() gives the caller full capabilities. |
| 268 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 269 | static void reparent_to_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | { |
| 271 | write_lock_irq(&tasklist_lock); |
| 272 | |
| 273 | ptrace_unlink(current); |
| 274 | /* Reparent to init */ |
Oleg Nesterov | 9b678ec | 2006-03-28 16:11:05 -0800 | [diff] [blame] | 275 | remove_parent(current); |
Sukadev Bhattiprolu | 84d7378 | 2006-12-08 02:38:01 -0800 | [diff] [blame] | 276 | current->parent = child_reaper(current); |
| 277 | current->real_parent = child_reaper(current); |
Oleg Nesterov | 9b678ec | 2006-03-28 16:11:05 -0800 | [diff] [blame] | 278 | add_parent(current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 279 | |
| 280 | /* Set the exit signal to SIGCHLD so we signal init on exit */ |
| 281 | current->exit_signal = SIGCHLD; |
| 282 | |
Oleg Nesterov | 1c573af | 2006-09-29 02:00:51 -0700 | [diff] [blame] | 283 | if (!has_rt_policy(current) && (task_nice(current) < 0)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | set_user_nice(current, 0); |
| 285 | /* cpus_allowed? */ |
| 286 | /* rt_priority? */ |
| 287 | /* signals? */ |
| 288 | security_task_reparent_to_init(current); |
| 289 | memcpy(current->signal->rlim, init_task.signal->rlim, |
| 290 | sizeof(current->signal->rlim)); |
| 291 | atomic_inc(&(INIT_USER->__count)); |
| 292 | write_unlock_irq(&tasklist_lock); |
| 293 | switch_uid(INIT_USER); |
| 294 | } |
| 295 | |
| 296 | void __set_special_pids(pid_t session, pid_t pgrp) |
| 297 | { |
Oren Laadan | e19f247 | 2006-01-08 01:03:58 -0800 | [diff] [blame] | 298 | struct task_struct *curr = current->group_leader; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 299 | |
Cedric Le Goater | 937949d | 2006-12-08 02:37:54 -0800 | [diff] [blame] | 300 | if (process_session(curr) != session) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | detach_pid(curr, PIDTYPE_SID); |
Cedric Le Goater | 1ec320a | 2006-12-08 02:37:55 -0800 | [diff] [blame] | 302 | set_signal_session(curr->signal, session); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | attach_pid(curr, PIDTYPE_SID, session); |
| 304 | } |
| 305 | if (process_group(curr) != pgrp) { |
| 306 | detach_pid(curr, PIDTYPE_PGID); |
| 307 | curr->signal->pgrp = pgrp; |
| 308 | attach_pid(curr, PIDTYPE_PGID, pgrp); |
| 309 | } |
| 310 | } |
| 311 | |
Oleg Nesterov | ae424ae | 2006-12-08 02:36:08 -0800 | [diff] [blame] | 312 | static void set_special_pids(pid_t session, pid_t pgrp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 313 | { |
| 314 | write_lock_irq(&tasklist_lock); |
| 315 | __set_special_pids(session, pgrp); |
| 316 | write_unlock_irq(&tasklist_lock); |
| 317 | } |
| 318 | |
| 319 | /* |
| 320 | * Let kernel threads use this to say that they |
| 321 | * allow a certain signal (since daemonize() will |
| 322 | * have disabled all of them by default). |
| 323 | */ |
| 324 | int allow_signal(int sig) |
| 325 | { |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 326 | if (!valid_signal(sig) || sig < 1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | return -EINVAL; |
| 328 | |
| 329 | spin_lock_irq(¤t->sighand->siglock); |
| 330 | sigdelset(¤t->blocked, sig); |
| 331 | if (!current->mm) { |
| 332 | /* Kernel threads handle their own signals. |
| 333 | Let the signal code know it'll be handled, so |
| 334 | that they don't get converted to SIGKILL or |
| 335 | just silently dropped */ |
| 336 | current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2; |
| 337 | } |
| 338 | recalc_sigpending(); |
| 339 | spin_unlock_irq(¤t->sighand->siglock); |
| 340 | return 0; |
| 341 | } |
| 342 | |
| 343 | EXPORT_SYMBOL(allow_signal); |
| 344 | |
| 345 | int disallow_signal(int sig) |
| 346 | { |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 347 | if (!valid_signal(sig) || sig < 1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | return -EINVAL; |
| 349 | |
| 350 | spin_lock_irq(¤t->sighand->siglock); |
| 351 | sigaddset(¤t->blocked, sig); |
| 352 | recalc_sigpending(); |
| 353 | spin_unlock_irq(¤t->sighand->siglock); |
| 354 | return 0; |
| 355 | } |
| 356 | |
| 357 | EXPORT_SYMBOL(disallow_signal); |
| 358 | |
| 359 | /* |
| 360 | * Put all the gunge required to become a kernel thread without |
| 361 | * attached user resources in one place where it belongs. |
| 362 | */ |
| 363 | |
| 364 | void daemonize(const char *name, ...) |
| 365 | { |
| 366 | va_list args; |
| 367 | struct fs_struct *fs; |
| 368 | sigset_t blocked; |
| 369 | |
| 370 | va_start(args, name); |
| 371 | vsnprintf(current->comm, sizeof(current->comm), name, args); |
| 372 | va_end(args); |
| 373 | |
| 374 | /* |
| 375 | * If we were started as result of loading a module, close all of the |
| 376 | * user space pages. We don't need them, and if we didn't close them |
| 377 | * they would be locked into memory. |
| 378 | */ |
| 379 | exit_mm(current); |
| 380 | |
| 381 | set_special_pids(1, 1); |
Peter Zijlstra | 24ec839 | 2006-12-08 02:36:04 -0800 | [diff] [blame] | 382 | proc_clear_tty(current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | |
| 384 | /* Block and flush all signals */ |
| 385 | sigfillset(&blocked); |
| 386 | sigprocmask(SIG_BLOCK, &blocked, NULL); |
| 387 | flush_signals(current); |
| 388 | |
| 389 | /* Become as one with the init task */ |
| 390 | |
| 391 | exit_fs(current); /* current->fs->count--; */ |
| 392 | fs = init_task.fs; |
| 393 | current->fs = fs; |
| 394 | atomic_inc(&fs->count); |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 395 | |
Linus Torvalds | 444f378 | 2007-01-30 13:35:18 -0800 | [diff] [blame] | 396 | exit_task_namespaces(current); |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 397 | current->nsproxy = init_task.nsproxy; |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 398 | get_task_namespaces(current); |
| 399 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | exit_files(current); |
| 401 | current->files = init_task.files; |
| 402 | atomic_inc(¤t->files->count); |
| 403 | |
| 404 | reparent_to_init(); |
| 405 | } |
| 406 | |
| 407 | EXPORT_SYMBOL(daemonize); |
| 408 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 409 | static void close_files(struct files_struct * files) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 410 | { |
| 411 | int i, j; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 412 | struct fdtable *fdt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | |
| 414 | j = 0; |
Dipankar Sarma | 4fb3a53 | 2005-09-16 19:28:13 -0700 | [diff] [blame] | 415 | |
| 416 | /* |
| 417 | * It is safe to dereference the fd table without RCU or |
| 418 | * ->file_lock because this is the last reference to the |
| 419 | * files structure. |
| 420 | */ |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 421 | fdt = files_fdtable(files); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 422 | for (;;) { |
| 423 | unsigned long set; |
| 424 | i = j * __NFDBITS; |
Vadim Lobanov | bbea9f6 | 2006-12-10 02:21:12 -0800 | [diff] [blame] | 425 | if (i >= fdt->max_fds) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 426 | break; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 427 | set = fdt->open_fds->fds_bits[j++]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 428 | while (set) { |
| 429 | if (set & 1) { |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 430 | struct file * file = xchg(&fdt->fd[i], NULL); |
Ingo Molnar | 944be0b | 2007-02-12 00:52:26 -0800 | [diff] [blame] | 431 | if (file) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | filp_close(file, files); |
Ingo Molnar | 944be0b | 2007-02-12 00:52:26 -0800 | [diff] [blame] | 433 | cond_resched(); |
| 434 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | } |
| 436 | i++; |
| 437 | set >>= 1; |
| 438 | } |
| 439 | } |
| 440 | } |
| 441 | |
| 442 | struct files_struct *get_files_struct(struct task_struct *task) |
| 443 | { |
| 444 | struct files_struct *files; |
| 445 | |
| 446 | task_lock(task); |
| 447 | files = task->files; |
| 448 | if (files) |
| 449 | atomic_inc(&files->count); |
| 450 | task_unlock(task); |
| 451 | |
| 452 | return files; |
| 453 | } |
| 454 | |
| 455 | void fastcall put_files_struct(struct files_struct *files) |
| 456 | { |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 457 | struct fdtable *fdt; |
| 458 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | if (atomic_dec_and_test(&files->count)) { |
| 460 | close_files(files); |
| 461 | /* |
| 462 | * Free the fd and fdset arrays if we expanded them. |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 463 | * If the fdtable was embedded, pass files for freeing |
| 464 | * at the end of the RCU grace period. Otherwise, |
| 465 | * you can free files immediately. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | */ |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 467 | fdt = files_fdtable(files); |
Vadim Lobanov | 4fd4581 | 2006-12-10 02:21:17 -0800 | [diff] [blame] | 468 | if (fdt != &files->fdtab) |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 469 | kmem_cache_free(files_cachep, files); |
Vadim Lobanov | 01b2d93 | 2006-12-22 01:10:43 -0800 | [diff] [blame] | 470 | free_fdtable(fdt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | } |
| 472 | } |
| 473 | |
| 474 | EXPORT_SYMBOL(put_files_struct); |
| 475 | |
Kirill Korotaev | 3b9b8ab | 2006-09-29 02:00:05 -0700 | [diff] [blame] | 476 | void reset_files_struct(struct task_struct *tsk, struct files_struct *files) |
| 477 | { |
| 478 | struct files_struct *old; |
| 479 | |
| 480 | old = tsk->files; |
| 481 | task_lock(tsk); |
| 482 | tsk->files = files; |
| 483 | task_unlock(tsk); |
| 484 | put_files_struct(old); |
| 485 | } |
| 486 | EXPORT_SYMBOL(reset_files_struct); |
| 487 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | static inline void __exit_files(struct task_struct *tsk) |
| 489 | { |
| 490 | struct files_struct * files = tsk->files; |
| 491 | |
| 492 | if (files) { |
| 493 | task_lock(tsk); |
| 494 | tsk->files = NULL; |
| 495 | task_unlock(tsk); |
| 496 | put_files_struct(files); |
| 497 | } |
| 498 | } |
| 499 | |
| 500 | void exit_files(struct task_struct *tsk) |
| 501 | { |
| 502 | __exit_files(tsk); |
| 503 | } |
| 504 | |
| 505 | static inline void __put_fs_struct(struct fs_struct *fs) |
| 506 | { |
| 507 | /* No need to hold fs->lock if we are killing it */ |
| 508 | if (atomic_dec_and_test(&fs->count)) { |
| 509 | dput(fs->root); |
| 510 | mntput(fs->rootmnt); |
| 511 | dput(fs->pwd); |
| 512 | mntput(fs->pwdmnt); |
| 513 | if (fs->altroot) { |
| 514 | dput(fs->altroot); |
| 515 | mntput(fs->altrootmnt); |
| 516 | } |
| 517 | kmem_cache_free(fs_cachep, fs); |
| 518 | } |
| 519 | } |
| 520 | |
| 521 | void put_fs_struct(struct fs_struct *fs) |
| 522 | { |
| 523 | __put_fs_struct(fs); |
| 524 | } |
| 525 | |
| 526 | static inline void __exit_fs(struct task_struct *tsk) |
| 527 | { |
| 528 | struct fs_struct * fs = tsk->fs; |
| 529 | |
| 530 | if (fs) { |
| 531 | task_lock(tsk); |
| 532 | tsk->fs = NULL; |
| 533 | task_unlock(tsk); |
| 534 | __put_fs_struct(fs); |
| 535 | } |
| 536 | } |
| 537 | |
| 538 | void exit_fs(struct task_struct *tsk) |
| 539 | { |
| 540 | __exit_fs(tsk); |
| 541 | } |
| 542 | |
| 543 | EXPORT_SYMBOL_GPL(exit_fs); |
| 544 | |
| 545 | /* |
| 546 | * Turn us into a lazy TLB process if we |
| 547 | * aren't already.. |
| 548 | */ |
Adrian Bunk | 408b664 | 2005-05-01 08:59:29 -0700 | [diff] [blame] | 549 | static void exit_mm(struct task_struct * tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 550 | { |
| 551 | struct mm_struct *mm = tsk->mm; |
| 552 | |
| 553 | mm_release(tsk, mm); |
| 554 | if (!mm) |
| 555 | return; |
| 556 | /* |
| 557 | * Serialize with any possible pending coredump. |
| 558 | * We must hold mmap_sem around checking core_waiters |
| 559 | * and clearing tsk->mm. The core-inducing thread |
| 560 | * will increment core_waiters for each thread in the |
| 561 | * group with ->mm != NULL. |
| 562 | */ |
| 563 | down_read(&mm->mmap_sem); |
| 564 | if (mm->core_waiters) { |
| 565 | up_read(&mm->mmap_sem); |
| 566 | down_write(&mm->mmap_sem); |
| 567 | if (!--mm->core_waiters) |
| 568 | complete(mm->core_startup_done); |
| 569 | up_write(&mm->mmap_sem); |
| 570 | |
| 571 | wait_for_completion(&mm->core_done); |
| 572 | down_read(&mm->mmap_sem); |
| 573 | } |
| 574 | atomic_inc(&mm->mm_count); |
Eric Sesterhenn | 125e187 | 2006-06-23 02:06:06 -0700 | [diff] [blame] | 575 | BUG_ON(mm != tsk->active_mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 576 | /* more a memory barrier than a real lock */ |
| 577 | task_lock(tsk); |
| 578 | tsk->mm = NULL; |
| 579 | up_read(&mm->mmap_sem); |
| 580 | enter_lazy_tlb(mm, current); |
| 581 | task_unlock(tsk); |
| 582 | mmput(mm); |
| 583 | } |
| 584 | |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 585 | static inline void |
| 586 | choose_new_parent(struct task_struct *p, struct task_struct *reaper) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 587 | { |
| 588 | /* |
| 589 | * Make sure we're not reparenting to ourselves and that |
| 590 | * the parent is not a zombie. |
| 591 | */ |
Oleg Nesterov | d799f03 | 2006-03-28 16:11:04 -0800 | [diff] [blame] | 592 | BUG_ON(p == reaper || reaper->exit_state); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 593 | p->real_parent = reaper; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | } |
| 595 | |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 596 | static void |
| 597 | reparent_thread(struct task_struct *p, struct task_struct *father, int traced) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 598 | { |
Oleg Nesterov | 241ceee | 2006-12-24 23:30:44 +0300 | [diff] [blame] | 599 | if (p->pdeath_signal) |
| 600 | /* We already hold the tasklist_lock here. */ |
| 601 | group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p); |
| 602 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 603 | /* Move the child from its dying parent to the new one. */ |
| 604 | if (unlikely(traced)) { |
| 605 | /* Preserve ptrace links if someone else is tracing this child. */ |
| 606 | list_del_init(&p->ptrace_list); |
| 607 | if (p->parent != p->real_parent) |
| 608 | list_add(&p->ptrace_list, &p->real_parent->ptrace_children); |
| 609 | } else { |
| 610 | /* If this child is being traced, then we're the one tracing it |
| 611 | * anyway, so let go of it. |
| 612 | */ |
| 613 | p->ptrace = 0; |
Oleg Nesterov | 6ac781b | 2006-03-28 16:11:09 -0800 | [diff] [blame] | 614 | remove_parent(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 615 | p->parent = p->real_parent; |
Oleg Nesterov | 6ac781b | 2006-03-28 16:11:09 -0800 | [diff] [blame] | 616 | add_parent(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | |
Eric W. Biederman | b2b2cbc | 2006-12-21 21:28:40 -0700 | [diff] [blame] | 618 | if (p->state == TASK_TRACED) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 619 | /* |
| 620 | * If it was at a trace stop, turn it into |
| 621 | * a normal stop since it's no longer being |
| 622 | * traced. |
| 623 | */ |
| 624 | ptrace_untrace(p); |
| 625 | } |
| 626 | } |
| 627 | |
Eric W. Biederman | b2b2cbc | 2006-12-21 21:28:40 -0700 | [diff] [blame] | 628 | /* If this is a threaded reparent there is no need to |
| 629 | * notify anyone anything has happened. |
| 630 | */ |
| 631 | if (p->real_parent->group_leader == father->group_leader) |
| 632 | return; |
| 633 | |
| 634 | /* We don't want people slaying init. */ |
| 635 | if (p->exit_signal != -1) |
| 636 | p->exit_signal = SIGCHLD; |
Eric W. Biederman | b2b2cbc | 2006-12-21 21:28:40 -0700 | [diff] [blame] | 637 | |
| 638 | /* If we'd notified the old parent about this child's death, |
| 639 | * also notify the new parent. |
| 640 | */ |
| 641 | if (!traced && p->exit_state == EXIT_ZOMBIE && |
| 642 | p->exit_signal != -1 && thread_group_empty(p)) |
| 643 | do_notify_parent(p, p->exit_signal); |
| 644 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | /* |
| 646 | * process group orphan check |
| 647 | * Case ii: Our child is in a different pgrp |
| 648 | * than we are, and it was the only connection |
| 649 | * outside, so the child pgrp is now orphaned. |
| 650 | */ |
| 651 | if ((process_group(p) != process_group(father)) && |
Cedric Le Goater | 937949d | 2006-12-08 02:37:54 -0800 | [diff] [blame] | 652 | (process_session(p) == process_session(father))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | int pgrp = process_group(p); |
| 654 | |
Cedric Le Goater | 937949d | 2006-12-08 02:37:54 -0800 | [diff] [blame] | 655 | if (will_become_orphaned_pgrp(pgrp, NULL) && |
| 656 | has_stopped_jobs(pgrp)) { |
Oleg Nesterov | b67a1b9 | 2005-10-30 15:03:44 -0800 | [diff] [blame] | 657 | __kill_pg_info(SIGHUP, SEND_SIG_PRIV, pgrp); |
| 658 | __kill_pg_info(SIGCONT, SEND_SIG_PRIV, pgrp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 659 | } |
| 660 | } |
| 661 | } |
| 662 | |
| 663 | /* |
| 664 | * When we die, we re-parent all our children. |
| 665 | * Try to give them to another thread in our thread |
| 666 | * group, and if no such member exists, give it to |
Sukadev Bhattiprolu | 84d7378 | 2006-12-08 02:38:01 -0800 | [diff] [blame] | 667 | * the child reaper process (ie "init") in our pid |
| 668 | * space. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | */ |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 670 | static void |
| 671 | forget_original_parent(struct task_struct *father, struct list_head *to_release) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 672 | { |
| 673 | struct task_struct *p, *reaper = father; |
| 674 | struct list_head *_p, *_n; |
| 675 | |
| 676 | do { |
| 677 | reaper = next_thread(reaper); |
| 678 | if (reaper == father) { |
Sukadev Bhattiprolu | 84d7378 | 2006-12-08 02:38:01 -0800 | [diff] [blame] | 679 | reaper = child_reaper(father); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 680 | break; |
| 681 | } |
| 682 | } while (reaper->exit_state); |
| 683 | |
| 684 | /* |
| 685 | * There are only two places where our children can be: |
| 686 | * |
| 687 | * - in our child list |
| 688 | * - in our ptraced child list |
| 689 | * |
| 690 | * Search them and reparent children. |
| 691 | */ |
| 692 | list_for_each_safe(_p, _n, &father->children) { |
| 693 | int ptrace; |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 694 | p = list_entry(_p, struct task_struct, sibling); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 695 | |
| 696 | ptrace = p->ptrace; |
| 697 | |
| 698 | /* if father isn't the real parent, then ptrace must be enabled */ |
| 699 | BUG_ON(father != p->real_parent && !ptrace); |
| 700 | |
| 701 | if (father == p->real_parent) { |
| 702 | /* reparent with a reaper, real father it's us */ |
Oleg Nesterov | d799f03 | 2006-03-28 16:11:04 -0800 | [diff] [blame] | 703 | choose_new_parent(p, reaper); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | reparent_thread(p, father, 0); |
| 705 | } else { |
| 706 | /* reparent ptraced task to its real parent */ |
| 707 | __ptrace_unlink (p); |
| 708 | if (p->exit_state == EXIT_ZOMBIE && p->exit_signal != -1 && |
| 709 | thread_group_empty(p)) |
| 710 | do_notify_parent(p, p->exit_signal); |
| 711 | } |
| 712 | |
| 713 | /* |
| 714 | * if the ptraced child is a zombie with exit_signal == -1 |
| 715 | * we must collect it before we exit, or it will remain |
| 716 | * zombie forever since we prevented it from self-reap itself |
| 717 | * while it was being traced by us, to be able to see it in wait4. |
| 718 | */ |
| 719 | if (unlikely(ptrace && p->exit_state == EXIT_ZOMBIE && p->exit_signal == -1)) |
| 720 | list_add(&p->ptrace_list, to_release); |
| 721 | } |
| 722 | list_for_each_safe(_p, _n, &father->ptrace_children) { |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 723 | p = list_entry(_p, struct task_struct, ptrace_list); |
Oleg Nesterov | d799f03 | 2006-03-28 16:11:04 -0800 | [diff] [blame] | 724 | choose_new_parent(p, reaper); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 725 | reparent_thread(p, father, 1); |
| 726 | } |
| 727 | } |
| 728 | |
| 729 | /* |
| 730 | * Send signals to all our closest relatives so that they know |
| 731 | * to properly mourn us.. |
| 732 | */ |
| 733 | static void exit_notify(struct task_struct *tsk) |
| 734 | { |
| 735 | int state; |
| 736 | struct task_struct *t; |
| 737 | struct list_head ptrace_dead, *_p, *_n; |
| 738 | |
| 739 | if (signal_pending(tsk) && !(tsk->signal->flags & SIGNAL_GROUP_EXIT) |
| 740 | && !thread_group_empty(tsk)) { |
| 741 | /* |
| 742 | * This occurs when there was a race between our exit |
| 743 | * syscall and a group signal choosing us as the one to |
| 744 | * wake up. It could be that we are the only thread |
| 745 | * alerted to check for pending signals, but another thread |
| 746 | * should be woken now to take the signal since we will not. |
| 747 | * Now we'll wake all the threads in the group just to make |
| 748 | * sure someone gets all the pending signals. |
| 749 | */ |
| 750 | read_lock(&tasklist_lock); |
| 751 | spin_lock_irq(&tsk->sighand->siglock); |
| 752 | for (t = next_thread(tsk); t != tsk; t = next_thread(t)) |
| 753 | if (!signal_pending(t) && !(t->flags & PF_EXITING)) { |
| 754 | recalc_sigpending_tsk(t); |
| 755 | if (signal_pending(t)) |
| 756 | signal_wake_up(t, 0); |
| 757 | } |
| 758 | spin_unlock_irq(&tsk->sighand->siglock); |
| 759 | read_unlock(&tasklist_lock); |
| 760 | } |
| 761 | |
| 762 | write_lock_irq(&tasklist_lock); |
| 763 | |
| 764 | /* |
| 765 | * This does two things: |
| 766 | * |
| 767 | * A. Make init inherit all the child processes |
| 768 | * B. Check to see if any process groups have become orphaned |
| 769 | * as a result of our exiting, and if they have any stopped |
| 770 | * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) |
| 771 | */ |
| 772 | |
| 773 | INIT_LIST_HEAD(&ptrace_dead); |
| 774 | forget_original_parent(tsk, &ptrace_dead); |
| 775 | BUG_ON(!list_empty(&tsk->children)); |
| 776 | BUG_ON(!list_empty(&tsk->ptrace_children)); |
| 777 | |
| 778 | /* |
| 779 | * Check to see if any process groups have become orphaned |
| 780 | * as a result of our exiting, and if they have any stopped |
| 781 | * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) |
| 782 | * |
| 783 | * Case i: Our father is in a different pgrp than we are |
| 784 | * and we were the only connection outside, so our pgrp |
| 785 | * is about to become orphaned. |
| 786 | */ |
| 787 | |
| 788 | t = tsk->real_parent; |
| 789 | |
| 790 | if ((process_group(t) != process_group(tsk)) && |
Cedric Le Goater | 937949d | 2006-12-08 02:37:54 -0800 | [diff] [blame] | 791 | (process_session(t) == process_session(tsk)) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 792 | will_become_orphaned_pgrp(process_group(tsk), tsk) && |
| 793 | has_stopped_jobs(process_group(tsk))) { |
Oleg Nesterov | b67a1b9 | 2005-10-30 15:03:44 -0800 | [diff] [blame] | 794 | __kill_pg_info(SIGHUP, SEND_SIG_PRIV, process_group(tsk)); |
| 795 | __kill_pg_info(SIGCONT, SEND_SIG_PRIV, process_group(tsk)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 796 | } |
| 797 | |
| 798 | /* Let father know we died |
| 799 | * |
| 800 | * Thread signals are configurable, but you aren't going to use |
| 801 | * that to send signals to arbitary processes. |
| 802 | * That stops right now. |
| 803 | * |
| 804 | * If the parent exec id doesn't match the exec id we saved |
| 805 | * when we started then we know the parent has changed security |
| 806 | * domain. |
| 807 | * |
| 808 | * If our self_exec id doesn't match our parent_exec_id then |
| 809 | * we have changed execution domain as these two values started |
| 810 | * the same after a fork. |
| 811 | * |
| 812 | */ |
| 813 | |
| 814 | if (tsk->exit_signal != SIGCHLD && tsk->exit_signal != -1 && |
| 815 | ( tsk->parent_exec_id != t->self_exec_id || |
| 816 | tsk->self_exec_id != tsk->parent_exec_id) |
| 817 | && !capable(CAP_KILL)) |
| 818 | tsk->exit_signal = SIGCHLD; |
| 819 | |
| 820 | |
| 821 | /* If something other than our normal parent is ptracing us, then |
| 822 | * send it a SIGCHLD instead of honoring exit_signal. exit_signal |
| 823 | * only has special meaning to our real parent. |
| 824 | */ |
| 825 | if (tsk->exit_signal != -1 && thread_group_empty(tsk)) { |
| 826 | int signal = tsk->parent == tsk->real_parent ? tsk->exit_signal : SIGCHLD; |
| 827 | do_notify_parent(tsk, signal); |
| 828 | } else if (tsk->ptrace) { |
| 829 | do_notify_parent(tsk, SIGCHLD); |
| 830 | } |
| 831 | |
| 832 | state = EXIT_ZOMBIE; |
| 833 | if (tsk->exit_signal == -1 && |
| 834 | (likely(tsk->ptrace == 0) || |
| 835 | unlikely(tsk->parent->signal->flags & SIGNAL_GROUP_EXIT))) |
| 836 | state = EXIT_DEAD; |
| 837 | tsk->exit_state = state; |
| 838 | |
| 839 | write_unlock_irq(&tasklist_lock); |
| 840 | |
| 841 | list_for_each_safe(_p, _n, &ptrace_dead) { |
| 842 | list_del_init(_p); |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 843 | t = list_entry(_p, struct task_struct, ptrace_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 844 | release_task(t); |
| 845 | } |
| 846 | |
| 847 | /* If the process is dead, release it - nobody will wait for it */ |
| 848 | if (state == EXIT_DEAD) |
| 849 | release_task(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 850 | } |
| 851 | |
| 852 | fastcall NORET_TYPE void do_exit(long code) |
| 853 | { |
| 854 | struct task_struct *tsk = current; |
| 855 | int group_dead; |
| 856 | |
| 857 | profile_task_exit(tsk); |
| 858 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 859 | WARN_ON(atomic_read(&tsk->fs_excl)); |
| 860 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 861 | if (unlikely(in_interrupt())) |
| 862 | panic("Aiee, killing interrupt handler!"); |
| 863 | if (unlikely(!tsk->pid)) |
| 864 | panic("Attempted to kill the idle task!"); |
Sukadev Bhattiprolu | 84d7378 | 2006-12-08 02:38:01 -0800 | [diff] [blame] | 865 | if (unlikely(tsk == child_reaper(tsk))) { |
| 866 | if (tsk->nsproxy->pid_ns != &init_pid_ns) |
| 867 | tsk->nsproxy->pid_ns->child_reaper = init_pid_ns.child_reaper; |
| 868 | else |
| 869 | panic("Attempted to kill init!"); |
| 870 | } |
| 871 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 872 | |
| 873 | if (unlikely(current->ptrace & PT_TRACE_EXIT)) { |
| 874 | current->ptrace_message = code; |
| 875 | ptrace_notify((PTRACE_EVENT_EXIT << 8) | SIGTRAP); |
| 876 | } |
| 877 | |
Alexander Nyberg | df164db | 2005-06-23 00:09:13 -0700 | [diff] [blame] | 878 | /* |
| 879 | * We're taking recursive faults here in do_exit. Safest is to just |
| 880 | * leave this task alone and wait for reboot. |
| 881 | */ |
| 882 | if (unlikely(tsk->flags & PF_EXITING)) { |
| 883 | printk(KERN_ALERT |
| 884 | "Fixing recursive fault but reboot is needed!\n"); |
Al Viro | afc847b | 2006-02-28 12:51:55 -0500 | [diff] [blame] | 885 | if (tsk->io_context) |
| 886 | exit_io_context(); |
Alexander Nyberg | df164db | 2005-06-23 00:09:13 -0700 | [diff] [blame] | 887 | set_current_state(TASK_UNINTERRUPTIBLE); |
| 888 | schedule(); |
| 889 | } |
| 890 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 891 | tsk->flags |= PF_EXITING; |
| 892 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 893 | if (unlikely(in_atomic())) |
| 894 | printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n", |
| 895 | current->comm, current->pid, |
| 896 | preempt_count()); |
| 897 | |
| 898 | acct_update_integrals(tsk); |
Hugh Dickins | 365e9c87 | 2005-10-29 18:16:18 -0700 | [diff] [blame] | 899 | if (tsk->mm) { |
| 900 | update_hiwater_rss(tsk->mm); |
| 901 | update_hiwater_vm(tsk->mm); |
| 902 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 903 | group_dead = atomic_dec_and_test(&tsk->signal->live); |
Andrew Morton | c306895 | 2005-08-04 16:49:32 -0700 | [diff] [blame] | 904 | if (group_dead) { |
Thomas Gleixner | 2ff678b | 2006-01-09 20:52:34 -0800 | [diff] [blame] | 905 | hrtimer_cancel(&tsk->signal->real_timer); |
Roland McGrath | 25f407f | 2005-10-21 15:03:29 -0700 | [diff] [blame] | 906 | exit_itimers(tsk->signal); |
Andrew Morton | c306895 | 2005-08-04 16:49:32 -0700 | [diff] [blame] | 907 | } |
KaiGai Kohei | f6ec29a | 2006-06-25 05:49:25 -0700 | [diff] [blame] | 908 | acct_collect(code, group_dead); |
Ingo Molnar | 0771dfe | 2006-03-27 01:16:22 -0800 | [diff] [blame] | 909 | if (unlikely(tsk->robust_list)) |
| 910 | exit_robust_list(tsk); |
Anton Blanchard | 2aa9258 | 2006-06-25 05:48:44 -0700 | [diff] [blame] | 911 | #if defined(CONFIG_FUTEX) && defined(CONFIG_COMPAT) |
Ingo Molnar | 34f192c | 2006-03-27 01:16:24 -0800 | [diff] [blame] | 912 | if (unlikely(tsk->compat_robust_list)) |
| 913 | compat_exit_robust_list(tsk); |
| 914 | #endif |
Al Viro | fa84cb9 | 2006-03-29 20:30:19 -0500 | [diff] [blame] | 915 | if (unlikely(tsk->audit_context)) |
| 916 | audit_free(tsk); |
Oleg Nesterov | 115085e | 2006-12-06 20:36:51 -0800 | [diff] [blame] | 917 | |
| 918 | taskstats_exit(tsk, group_dead); |
Shailabh Nagar | c757249 | 2006-07-14 00:24:40 -0700 | [diff] [blame] | 919 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 920 | exit_mm(tsk); |
| 921 | |
KaiGai Kohei | 0e46481 | 2006-06-25 05:49:24 -0700 | [diff] [blame] | 922 | if (group_dead) |
KaiGai Kohei | f6ec29a | 2006-06-25 05:49:25 -0700 | [diff] [blame] | 923 | acct_process(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 924 | exit_sem(tsk); |
| 925 | __exit_files(tsk); |
| 926 | __exit_fs(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 927 | exit_thread(); |
| 928 | cpuset_exit(tsk); |
| 929 | exit_keys(tsk); |
| 930 | |
| 931 | if (group_dead && tsk->signal->leader) |
| 932 | disassociate_ctty(1); |
| 933 | |
Al Viro | a1261f5 | 2005-11-13 16:06:55 -0800 | [diff] [blame] | 934 | module_put(task_thread_info(tsk)->exec_domain->module); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 935 | if (tsk->binfmt) |
| 936 | module_put(tsk->binfmt->module); |
| 937 | |
| 938 | tsk->exit_code = code; |
Matt Helsley | 9f46080 | 2005-11-07 00:59:16 -0800 | [diff] [blame] | 939 | proc_exit_connector(tsk); |
Linus Torvalds | 444f378 | 2007-01-30 13:35:18 -0800 | [diff] [blame] | 940 | exit_task_namespaces(tsk); |
Serge E. Hallyn | 0f24528 | 2007-01-30 15:28:23 -0600 | [diff] [blame] | 941 | exit_notify(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 942 | #ifdef CONFIG_NUMA |
| 943 | mpol_free(tsk->mempolicy); |
| 944 | tsk->mempolicy = NULL; |
| 945 | #endif |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 946 | /* |
Ingo Molnar | c87e283 | 2006-06-27 02:54:58 -0700 | [diff] [blame] | 947 | * This must happen late, after the PID is not |
| 948 | * hashed anymore: |
| 949 | */ |
| 950 | if (unlikely(!list_empty(&tsk->pi_state_list))) |
| 951 | exit_pi_state_list(tsk); |
| 952 | if (unlikely(current->pi_state_cache)) |
| 953 | kfree(current->pi_state_cache); |
| 954 | /* |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 955 | * Make sure we are holding no locks: |
Ingo Molnar | de5097c | 2006-01-09 15:59:21 -0800 | [diff] [blame] | 956 | */ |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 957 | debug_check_no_locks_held(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 958 | |
Al Viro | afc847b | 2006-02-28 12:51:55 -0500 | [diff] [blame] | 959 | if (tsk->io_context) |
| 960 | exit_io_context(); |
| 961 | |
Jens Axboe | b92ce55 | 2006-04-11 13:52:07 +0200 | [diff] [blame] | 962 | if (tsk->splice_pipe) |
| 963 | __free_pipe_info(tsk->splice_pipe); |
| 964 | |
Coywolf Qi Hunt | 7407251 | 2005-10-30 15:02:47 -0800 | [diff] [blame] | 965 | preempt_disable(); |
Oleg Nesterov | 55a101f | 2006-09-29 02:01:10 -0700 | [diff] [blame] | 966 | /* causes final put_task_struct in finish_task_switch(). */ |
Oleg Nesterov | c394cc9 | 2006-09-29 02:01:11 -0700 | [diff] [blame] | 967 | tsk->state = TASK_DEAD; |
Coywolf Qi Hunt | 7407251 | 2005-10-30 15:02:47 -0800 | [diff] [blame] | 968 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 969 | schedule(); |
| 970 | BUG(); |
| 971 | /* Avoid "noreturn function does return". */ |
Alan Cox | 54306cf | 2006-09-29 02:00:42 -0700 | [diff] [blame] | 972 | for (;;) |
| 973 | cpu_relax(); /* For when BUG is null */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 974 | } |
| 975 | |
Russ Anderson | 012914d | 2005-04-23 00:08:00 -0700 | [diff] [blame] | 976 | EXPORT_SYMBOL_GPL(do_exit); |
| 977 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 978 | NORET_TYPE void complete_and_exit(struct completion *comp, long code) |
| 979 | { |
| 980 | if (comp) |
| 981 | complete(comp); |
Oleg Nesterov | 55a101f | 2006-09-29 02:01:10 -0700 | [diff] [blame] | 982 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 983 | do_exit(code); |
| 984 | } |
| 985 | |
| 986 | EXPORT_SYMBOL(complete_and_exit); |
| 987 | |
| 988 | asmlinkage long sys_exit(int error_code) |
| 989 | { |
| 990 | do_exit((error_code&0xff)<<8); |
| 991 | } |
| 992 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 993 | /* |
| 994 | * Take down every thread in the group. This is called by fatal signals |
| 995 | * as well as by sys_exit_group (below). |
| 996 | */ |
| 997 | NORET_TYPE void |
| 998 | do_group_exit(int exit_code) |
| 999 | { |
| 1000 | BUG_ON(exit_code & 0x80); /* core dumps don't get here */ |
| 1001 | |
| 1002 | if (current->signal->flags & SIGNAL_GROUP_EXIT) |
| 1003 | exit_code = current->signal->group_exit_code; |
| 1004 | else if (!thread_group_empty(current)) { |
| 1005 | struct signal_struct *const sig = current->signal; |
| 1006 | struct sighand_struct *const sighand = current->sighand; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1007 | spin_lock_irq(&sighand->siglock); |
| 1008 | if (sig->flags & SIGNAL_GROUP_EXIT) |
| 1009 | /* Another thread got here before we took the lock. */ |
| 1010 | exit_code = sig->group_exit_code; |
| 1011 | else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1012 | sig->group_exit_code = exit_code; |
| 1013 | zap_other_threads(current); |
| 1014 | } |
| 1015 | spin_unlock_irq(&sighand->siglock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1016 | } |
| 1017 | |
| 1018 | do_exit(exit_code); |
| 1019 | /* NOTREACHED */ |
| 1020 | } |
| 1021 | |
| 1022 | /* |
| 1023 | * this kills every thread in the thread group. Note that any externally |
| 1024 | * wait4()-ing process will get the correct exit code - even if this |
| 1025 | * thread is not the thread group leader. |
| 1026 | */ |
| 1027 | asmlinkage void sys_exit_group(int error_code) |
| 1028 | { |
| 1029 | do_group_exit((error_code & 0xff) << 8); |
| 1030 | } |
| 1031 | |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 1032 | static int eligible_child(pid_t pid, int options, struct task_struct *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1033 | { |
| 1034 | if (pid > 0) { |
| 1035 | if (p->pid != pid) |
| 1036 | return 0; |
| 1037 | } else if (!pid) { |
| 1038 | if (process_group(p) != process_group(current)) |
| 1039 | return 0; |
| 1040 | } else if (pid != -1) { |
| 1041 | if (process_group(p) != -pid) |
| 1042 | return 0; |
| 1043 | } |
| 1044 | |
| 1045 | /* |
| 1046 | * Do not consider detached threads that are |
| 1047 | * not ptraced: |
| 1048 | */ |
| 1049 | if (p->exit_signal == -1 && !p->ptrace) |
| 1050 | return 0; |
| 1051 | |
| 1052 | /* Wait for all children (clone and not) if __WALL is set; |
| 1053 | * otherwise, wait for clone children *only* if __WCLONE is |
| 1054 | * set; otherwise, wait for non-clone children *only*. (Note: |
| 1055 | * A "clone" child here is one that reports to its parent |
| 1056 | * using a signal other than SIGCHLD.) */ |
| 1057 | if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0)) |
| 1058 | && !(options & __WALL)) |
| 1059 | return 0; |
| 1060 | /* |
| 1061 | * Do not consider thread group leaders that are |
| 1062 | * in a non-empty thread group: |
| 1063 | */ |
Oleg Nesterov | 3b6362b | 2006-09-02 21:22:16 +0400 | [diff] [blame] | 1064 | if (delay_group_leader(p)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1065 | return 2; |
| 1066 | |
| 1067 | if (security_task_wait(p)) |
| 1068 | return 0; |
| 1069 | |
| 1070 | return 1; |
| 1071 | } |
| 1072 | |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 1073 | static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | int why, int status, |
| 1075 | struct siginfo __user *infop, |
| 1076 | struct rusage __user *rusagep) |
| 1077 | { |
| 1078 | int retval = rusagep ? getrusage(p, RUSAGE_BOTH, rusagep) : 0; |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 1079 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1080 | put_task_struct(p); |
| 1081 | if (!retval) |
| 1082 | retval = put_user(SIGCHLD, &infop->si_signo); |
| 1083 | if (!retval) |
| 1084 | retval = put_user(0, &infop->si_errno); |
| 1085 | if (!retval) |
| 1086 | retval = put_user((short)why, &infop->si_code); |
| 1087 | if (!retval) |
| 1088 | retval = put_user(pid, &infop->si_pid); |
| 1089 | if (!retval) |
| 1090 | retval = put_user(uid, &infop->si_uid); |
| 1091 | if (!retval) |
| 1092 | retval = put_user(status, &infop->si_status); |
| 1093 | if (!retval) |
| 1094 | retval = pid; |
| 1095 | return retval; |
| 1096 | } |
| 1097 | |
| 1098 | /* |
| 1099 | * Handle sys_wait4 work for one task in state EXIT_ZOMBIE. We hold |
| 1100 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold |
| 1101 | * the lock and this task is uninteresting. If we return nonzero, we have |
| 1102 | * released the lock and the system call should return. |
| 1103 | */ |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 1104 | static int wait_task_zombie(struct task_struct *p, int noreap, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1105 | struct siginfo __user *infop, |
| 1106 | int __user *stat_addr, struct rusage __user *ru) |
| 1107 | { |
| 1108 | unsigned long state; |
| 1109 | int retval; |
| 1110 | int status; |
| 1111 | |
| 1112 | if (unlikely(noreap)) { |
| 1113 | pid_t pid = p->pid; |
| 1114 | uid_t uid = p->uid; |
| 1115 | int exit_code = p->exit_code; |
| 1116 | int why, status; |
| 1117 | |
| 1118 | if (unlikely(p->exit_state != EXIT_ZOMBIE)) |
| 1119 | return 0; |
| 1120 | if (unlikely(p->exit_signal == -1 && p->ptrace == 0)) |
| 1121 | return 0; |
| 1122 | get_task_struct(p); |
| 1123 | read_unlock(&tasklist_lock); |
| 1124 | if ((exit_code & 0x7f) == 0) { |
| 1125 | why = CLD_EXITED; |
| 1126 | status = exit_code >> 8; |
| 1127 | } else { |
| 1128 | why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED; |
| 1129 | status = exit_code & 0x7f; |
| 1130 | } |
| 1131 | return wait_noreap_copyout(p, pid, uid, why, |
| 1132 | status, infop, ru); |
| 1133 | } |
| 1134 | |
| 1135 | /* |
| 1136 | * Try to move the task's state to DEAD |
| 1137 | * only one thread is allowed to do this: |
| 1138 | */ |
| 1139 | state = xchg(&p->exit_state, EXIT_DEAD); |
| 1140 | if (state != EXIT_ZOMBIE) { |
| 1141 | BUG_ON(state != EXIT_DEAD); |
| 1142 | return 0; |
| 1143 | } |
| 1144 | if (unlikely(p->exit_signal == -1 && p->ptrace == 0)) { |
| 1145 | /* |
| 1146 | * This can only happen in a race with a ptraced thread |
| 1147 | * dying on another processor. |
| 1148 | */ |
| 1149 | return 0; |
| 1150 | } |
| 1151 | |
| 1152 | if (likely(p->real_parent == p->parent) && likely(p->signal)) { |
Jesper Juhl | 3795e16 | 2006-01-09 20:54:39 -0800 | [diff] [blame] | 1153 | struct signal_struct *psig; |
| 1154 | struct signal_struct *sig; |
| 1155 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1156 | /* |
| 1157 | * The resource counters for the group leader are in its |
| 1158 | * own task_struct. Those for dead threads in the group |
| 1159 | * are in its signal_struct, as are those for the child |
| 1160 | * processes it has previously reaped. All these |
| 1161 | * accumulate in the parent's signal_struct c* fields. |
| 1162 | * |
| 1163 | * We don't bother to take a lock here to protect these |
| 1164 | * p->signal fields, because they are only touched by |
| 1165 | * __exit_signal, which runs with tasklist_lock |
| 1166 | * write-locked anyway, and so is excluded here. We do |
| 1167 | * need to protect the access to p->parent->signal fields, |
| 1168 | * as other threads in the parent group can be right |
| 1169 | * here reaping other children at the same time. |
| 1170 | */ |
| 1171 | spin_lock_irq(&p->parent->sighand->siglock); |
Jesper Juhl | 3795e16 | 2006-01-09 20:54:39 -0800 | [diff] [blame] | 1172 | psig = p->parent->signal; |
| 1173 | sig = p->signal; |
| 1174 | psig->cutime = |
| 1175 | cputime_add(psig->cutime, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1176 | cputime_add(p->utime, |
Jesper Juhl | 3795e16 | 2006-01-09 20:54:39 -0800 | [diff] [blame] | 1177 | cputime_add(sig->utime, |
| 1178 | sig->cutime))); |
| 1179 | psig->cstime = |
| 1180 | cputime_add(psig->cstime, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1181 | cputime_add(p->stime, |
Jesper Juhl | 3795e16 | 2006-01-09 20:54:39 -0800 | [diff] [blame] | 1182 | cputime_add(sig->stime, |
| 1183 | sig->cstime))); |
| 1184 | psig->cmin_flt += |
| 1185 | p->min_flt + sig->min_flt + sig->cmin_flt; |
| 1186 | psig->cmaj_flt += |
| 1187 | p->maj_flt + sig->maj_flt + sig->cmaj_flt; |
| 1188 | psig->cnvcsw += |
| 1189 | p->nvcsw + sig->nvcsw + sig->cnvcsw; |
| 1190 | psig->cnivcsw += |
| 1191 | p->nivcsw + sig->nivcsw + sig->cnivcsw; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1192 | spin_unlock_irq(&p->parent->sighand->siglock); |
| 1193 | } |
| 1194 | |
| 1195 | /* |
| 1196 | * Now we are sure this task is interesting, and no other |
| 1197 | * thread can reap it because we set its state to EXIT_DEAD. |
| 1198 | */ |
| 1199 | read_unlock(&tasklist_lock); |
| 1200 | |
| 1201 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; |
| 1202 | status = (p->signal->flags & SIGNAL_GROUP_EXIT) |
| 1203 | ? p->signal->group_exit_code : p->exit_code; |
| 1204 | if (!retval && stat_addr) |
| 1205 | retval = put_user(status, stat_addr); |
| 1206 | if (!retval && infop) |
| 1207 | retval = put_user(SIGCHLD, &infop->si_signo); |
| 1208 | if (!retval && infop) |
| 1209 | retval = put_user(0, &infop->si_errno); |
| 1210 | if (!retval && infop) { |
| 1211 | int why; |
| 1212 | |
| 1213 | if ((status & 0x7f) == 0) { |
| 1214 | why = CLD_EXITED; |
| 1215 | status >>= 8; |
| 1216 | } else { |
| 1217 | why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED; |
| 1218 | status &= 0x7f; |
| 1219 | } |
| 1220 | retval = put_user((short)why, &infop->si_code); |
| 1221 | if (!retval) |
| 1222 | retval = put_user(status, &infop->si_status); |
| 1223 | } |
| 1224 | if (!retval && infop) |
| 1225 | retval = put_user(p->pid, &infop->si_pid); |
| 1226 | if (!retval && infop) |
| 1227 | retval = put_user(p->uid, &infop->si_uid); |
| 1228 | if (retval) { |
| 1229 | // TODO: is this safe? |
| 1230 | p->exit_state = EXIT_ZOMBIE; |
| 1231 | return retval; |
| 1232 | } |
| 1233 | retval = p->pid; |
| 1234 | if (p->real_parent != p->parent) { |
| 1235 | write_lock_irq(&tasklist_lock); |
| 1236 | /* Double-check with lock held. */ |
| 1237 | if (p->real_parent != p->parent) { |
| 1238 | __ptrace_unlink(p); |
| 1239 | // TODO: is this safe? |
| 1240 | p->exit_state = EXIT_ZOMBIE; |
| 1241 | /* |
| 1242 | * If this is not a detached task, notify the parent. |
| 1243 | * If it's still not detached after that, don't release |
| 1244 | * it now. |
| 1245 | */ |
| 1246 | if (p->exit_signal != -1) { |
| 1247 | do_notify_parent(p, p->exit_signal); |
| 1248 | if (p->exit_signal != -1) |
| 1249 | p = NULL; |
| 1250 | } |
| 1251 | } |
| 1252 | write_unlock_irq(&tasklist_lock); |
| 1253 | } |
| 1254 | if (p != NULL) |
| 1255 | release_task(p); |
| 1256 | BUG_ON(!retval); |
| 1257 | return retval; |
| 1258 | } |
| 1259 | |
| 1260 | /* |
| 1261 | * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold |
| 1262 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold |
| 1263 | * the lock and this task is uninteresting. If we return nonzero, we have |
| 1264 | * released the lock and the system call should return. |
| 1265 | */ |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 1266 | static int wait_task_stopped(struct task_struct *p, int delayed_group_leader, |
| 1267 | int noreap, struct siginfo __user *infop, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1268 | int __user *stat_addr, struct rusage __user *ru) |
| 1269 | { |
| 1270 | int retval, exit_code; |
| 1271 | |
| 1272 | if (!p->exit_code) |
| 1273 | return 0; |
| 1274 | if (delayed_group_leader && !(p->ptrace & PT_PTRACED) && |
| 1275 | p->signal && p->signal->group_stop_count > 0) |
| 1276 | /* |
| 1277 | * A group stop is in progress and this is the group leader. |
| 1278 | * We won't report until all threads have stopped. |
| 1279 | */ |
| 1280 | return 0; |
| 1281 | |
| 1282 | /* |
| 1283 | * Now we are pretty sure this task is interesting. |
| 1284 | * Make sure it doesn't get reaped out from under us while we |
| 1285 | * give up the lock and then examine it below. We don't want to |
| 1286 | * keep holding onto the tasklist_lock while we call getrusage and |
| 1287 | * possibly take page faults for user memory. |
| 1288 | */ |
| 1289 | get_task_struct(p); |
| 1290 | read_unlock(&tasklist_lock); |
| 1291 | |
| 1292 | if (unlikely(noreap)) { |
| 1293 | pid_t pid = p->pid; |
| 1294 | uid_t uid = p->uid; |
| 1295 | int why = (p->ptrace & PT_PTRACED) ? CLD_TRAPPED : CLD_STOPPED; |
| 1296 | |
| 1297 | exit_code = p->exit_code; |
| 1298 | if (unlikely(!exit_code) || |
Linus Torvalds | 14bf01b | 2005-10-01 11:04:18 -0700 | [diff] [blame] | 1299 | unlikely(p->state & TASK_TRACED)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1300 | goto bail_ref; |
| 1301 | return wait_noreap_copyout(p, pid, uid, |
| 1302 | why, (exit_code << 8) | 0x7f, |
| 1303 | infop, ru); |
| 1304 | } |
| 1305 | |
| 1306 | write_lock_irq(&tasklist_lock); |
| 1307 | |
| 1308 | /* |
| 1309 | * This uses xchg to be atomic with the thread resuming and setting |
| 1310 | * it. It must also be done with the write lock held to prevent a |
| 1311 | * race with the EXIT_ZOMBIE case. |
| 1312 | */ |
| 1313 | exit_code = xchg(&p->exit_code, 0); |
| 1314 | if (unlikely(p->exit_state)) { |
| 1315 | /* |
| 1316 | * The task resumed and then died. Let the next iteration |
| 1317 | * catch it in EXIT_ZOMBIE. Note that exit_code might |
| 1318 | * already be zero here if it resumed and did _exit(0). |
| 1319 | * The task itself is dead and won't touch exit_code again; |
| 1320 | * other processors in this function are locked out. |
| 1321 | */ |
| 1322 | p->exit_code = exit_code; |
| 1323 | exit_code = 0; |
| 1324 | } |
| 1325 | if (unlikely(exit_code == 0)) { |
| 1326 | /* |
| 1327 | * Another thread in this function got to it first, or it |
| 1328 | * resumed, or it resumed and then died. |
| 1329 | */ |
| 1330 | write_unlock_irq(&tasklist_lock); |
| 1331 | bail_ref: |
| 1332 | put_task_struct(p); |
| 1333 | /* |
| 1334 | * We are returning to the wait loop without having successfully |
| 1335 | * removed the process and having released the lock. We cannot |
| 1336 | * continue, since the "p" task pointer is potentially stale. |
| 1337 | * |
| 1338 | * Return -EAGAIN, and do_wait() will restart the loop from the |
| 1339 | * beginning. Do _not_ re-acquire the lock. |
| 1340 | */ |
| 1341 | return -EAGAIN; |
| 1342 | } |
| 1343 | |
| 1344 | /* move to end of parent's list to avoid starvation */ |
| 1345 | remove_parent(p); |
Oleg Nesterov | 8fafabd | 2006-03-28 16:11:05 -0800 | [diff] [blame] | 1346 | add_parent(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1347 | |
| 1348 | write_unlock_irq(&tasklist_lock); |
| 1349 | |
| 1350 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; |
| 1351 | if (!retval && stat_addr) |
| 1352 | retval = put_user((exit_code << 8) | 0x7f, stat_addr); |
| 1353 | if (!retval && infop) |
| 1354 | retval = put_user(SIGCHLD, &infop->si_signo); |
| 1355 | if (!retval && infop) |
| 1356 | retval = put_user(0, &infop->si_errno); |
| 1357 | if (!retval && infop) |
| 1358 | retval = put_user((short)((p->ptrace & PT_PTRACED) |
| 1359 | ? CLD_TRAPPED : CLD_STOPPED), |
| 1360 | &infop->si_code); |
| 1361 | if (!retval && infop) |
| 1362 | retval = put_user(exit_code, &infop->si_status); |
| 1363 | if (!retval && infop) |
| 1364 | retval = put_user(p->pid, &infop->si_pid); |
| 1365 | if (!retval && infop) |
| 1366 | retval = put_user(p->uid, &infop->si_uid); |
| 1367 | if (!retval) |
| 1368 | retval = p->pid; |
| 1369 | put_task_struct(p); |
| 1370 | |
| 1371 | BUG_ON(!retval); |
| 1372 | return retval; |
| 1373 | } |
| 1374 | |
| 1375 | /* |
| 1376 | * Handle do_wait work for one task in a live, non-stopped state. |
| 1377 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold |
| 1378 | * the lock and this task is uninteresting. If we return nonzero, we have |
| 1379 | * released the lock and the system call should return. |
| 1380 | */ |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 1381 | static int wait_task_continued(struct task_struct *p, int noreap, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1382 | struct siginfo __user *infop, |
| 1383 | int __user *stat_addr, struct rusage __user *ru) |
| 1384 | { |
| 1385 | int retval; |
| 1386 | pid_t pid; |
| 1387 | uid_t uid; |
| 1388 | |
| 1389 | if (unlikely(!p->signal)) |
| 1390 | return 0; |
| 1391 | |
| 1392 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) |
| 1393 | return 0; |
| 1394 | |
| 1395 | spin_lock_irq(&p->sighand->siglock); |
| 1396 | /* Re-check with the lock held. */ |
| 1397 | if (!(p->signal->flags & SIGNAL_STOP_CONTINUED)) { |
| 1398 | spin_unlock_irq(&p->sighand->siglock); |
| 1399 | return 0; |
| 1400 | } |
| 1401 | if (!noreap) |
| 1402 | p->signal->flags &= ~SIGNAL_STOP_CONTINUED; |
| 1403 | spin_unlock_irq(&p->sighand->siglock); |
| 1404 | |
| 1405 | pid = p->pid; |
| 1406 | uid = p->uid; |
| 1407 | get_task_struct(p); |
| 1408 | read_unlock(&tasklist_lock); |
| 1409 | |
| 1410 | if (!infop) { |
| 1411 | retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; |
| 1412 | put_task_struct(p); |
| 1413 | if (!retval && stat_addr) |
| 1414 | retval = put_user(0xffff, stat_addr); |
| 1415 | if (!retval) |
| 1416 | retval = p->pid; |
| 1417 | } else { |
| 1418 | retval = wait_noreap_copyout(p, pid, uid, |
| 1419 | CLD_CONTINUED, SIGCONT, |
| 1420 | infop, ru); |
| 1421 | BUG_ON(retval == 0); |
| 1422 | } |
| 1423 | |
| 1424 | return retval; |
| 1425 | } |
| 1426 | |
| 1427 | |
| 1428 | static inline int my_ptrace_child(struct task_struct *p) |
| 1429 | { |
| 1430 | if (!(p->ptrace & PT_PTRACED)) |
| 1431 | return 0; |
| 1432 | if (!(p->ptrace & PT_ATTACHED)) |
| 1433 | return 1; |
| 1434 | /* |
| 1435 | * This child was PTRACE_ATTACH'd. We should be seeing it only if |
| 1436 | * we are the attacher. If we are the real parent, this is a race |
| 1437 | * inside ptrace_attach. It is waiting for the tasklist_lock, |
| 1438 | * which we have to switch the parent links, but has already set |
| 1439 | * the flags in p->ptrace. |
| 1440 | */ |
| 1441 | return (p->parent != p->real_parent); |
| 1442 | } |
| 1443 | |
| 1444 | static long do_wait(pid_t pid, int options, struct siginfo __user *infop, |
| 1445 | int __user *stat_addr, struct rusage __user *ru) |
| 1446 | { |
| 1447 | DECLARE_WAITQUEUE(wait, current); |
| 1448 | struct task_struct *tsk; |
| 1449 | int flag, retval; |
| 1450 | |
| 1451 | add_wait_queue(¤t->signal->wait_chldexit,&wait); |
| 1452 | repeat: |
| 1453 | /* |
| 1454 | * We will set this flag if we see any child that might later |
| 1455 | * match our criteria, even if we are not able to reap it yet. |
| 1456 | */ |
| 1457 | flag = 0; |
| 1458 | current->state = TASK_INTERRUPTIBLE; |
| 1459 | read_lock(&tasklist_lock); |
| 1460 | tsk = current; |
| 1461 | do { |
| 1462 | struct task_struct *p; |
| 1463 | struct list_head *_p; |
| 1464 | int ret; |
| 1465 | |
| 1466 | list_for_each(_p,&tsk->children) { |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 1467 | p = list_entry(_p, struct task_struct, sibling); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1468 | |
| 1469 | ret = eligible_child(pid, options, p); |
| 1470 | if (!ret) |
| 1471 | continue; |
| 1472 | |
| 1473 | switch (p->state) { |
| 1474 | case TASK_TRACED: |
Roland McGrath | 7f2a525 | 2005-10-30 15:02:50 -0800 | [diff] [blame] | 1475 | /* |
| 1476 | * When we hit the race with PTRACE_ATTACH, |
| 1477 | * we will not report this child. But the |
| 1478 | * race means it has not yet been moved to |
| 1479 | * our ptrace_children list, so we need to |
| 1480 | * set the flag here to avoid a spurious ECHILD |
| 1481 | * when the race happens with the only child. |
| 1482 | */ |
| 1483 | flag = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1484 | if (!my_ptrace_child(p)) |
| 1485 | continue; |
| 1486 | /*FALLTHROUGH*/ |
| 1487 | case TASK_STOPPED: |
| 1488 | /* |
| 1489 | * It's stopped now, so it might later |
| 1490 | * continue, exit, or stop again. |
| 1491 | */ |
| 1492 | flag = 1; |
| 1493 | if (!(options & WUNTRACED) && |
| 1494 | !my_ptrace_child(p)) |
| 1495 | continue; |
| 1496 | retval = wait_task_stopped(p, ret == 2, |
| 1497 | (options & WNOWAIT), |
| 1498 | infop, |
| 1499 | stat_addr, ru); |
| 1500 | if (retval == -EAGAIN) |
| 1501 | goto repeat; |
| 1502 | if (retval != 0) /* He released the lock. */ |
| 1503 | goto end; |
| 1504 | break; |
| 1505 | default: |
| 1506 | // case EXIT_DEAD: |
| 1507 | if (p->exit_state == EXIT_DEAD) |
| 1508 | continue; |
| 1509 | // case EXIT_ZOMBIE: |
| 1510 | if (p->exit_state == EXIT_ZOMBIE) { |
| 1511 | /* |
| 1512 | * Eligible but we cannot release |
| 1513 | * it yet: |
| 1514 | */ |
| 1515 | if (ret == 2) |
| 1516 | goto check_continued; |
| 1517 | if (!likely(options & WEXITED)) |
| 1518 | continue; |
| 1519 | retval = wait_task_zombie( |
| 1520 | p, (options & WNOWAIT), |
| 1521 | infop, stat_addr, ru); |
| 1522 | /* He released the lock. */ |
| 1523 | if (retval != 0) |
| 1524 | goto end; |
| 1525 | break; |
| 1526 | } |
| 1527 | check_continued: |
| 1528 | /* |
| 1529 | * It's running now, so it might later |
| 1530 | * exit, stop, or stop and then continue. |
| 1531 | */ |
| 1532 | flag = 1; |
| 1533 | if (!unlikely(options & WCONTINUED)) |
| 1534 | continue; |
| 1535 | retval = wait_task_continued( |
| 1536 | p, (options & WNOWAIT), |
| 1537 | infop, stat_addr, ru); |
| 1538 | if (retval != 0) /* He released the lock. */ |
| 1539 | goto end; |
| 1540 | break; |
| 1541 | } |
| 1542 | } |
| 1543 | if (!flag) { |
| 1544 | list_for_each(_p, &tsk->ptrace_children) { |
| 1545 | p = list_entry(_p, struct task_struct, |
| 1546 | ptrace_list); |
| 1547 | if (!eligible_child(pid, options, p)) |
| 1548 | continue; |
| 1549 | flag = 1; |
| 1550 | break; |
| 1551 | } |
| 1552 | } |
| 1553 | if (options & __WNOTHREAD) |
| 1554 | break; |
| 1555 | tsk = next_thread(tsk); |
Eric Sesterhenn | 125e187 | 2006-06-23 02:06:06 -0700 | [diff] [blame] | 1556 | BUG_ON(tsk->signal != current->signal); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1557 | } while (tsk != current); |
| 1558 | |
| 1559 | read_unlock(&tasklist_lock); |
| 1560 | if (flag) { |
| 1561 | retval = 0; |
| 1562 | if (options & WNOHANG) |
| 1563 | goto end; |
| 1564 | retval = -ERESTARTSYS; |
| 1565 | if (signal_pending(current)) |
| 1566 | goto end; |
| 1567 | schedule(); |
| 1568 | goto repeat; |
| 1569 | } |
| 1570 | retval = -ECHILD; |
| 1571 | end: |
| 1572 | current->state = TASK_RUNNING; |
| 1573 | remove_wait_queue(¤t->signal->wait_chldexit,&wait); |
| 1574 | if (infop) { |
| 1575 | if (retval > 0) |
| 1576 | retval = 0; |
| 1577 | else { |
| 1578 | /* |
| 1579 | * For a WNOHANG return, clear out all the fields |
| 1580 | * we would set so the user can easily tell the |
| 1581 | * difference. |
| 1582 | */ |
| 1583 | if (!retval) |
| 1584 | retval = put_user(0, &infop->si_signo); |
| 1585 | if (!retval) |
| 1586 | retval = put_user(0, &infop->si_errno); |
| 1587 | if (!retval) |
| 1588 | retval = put_user(0, &infop->si_code); |
| 1589 | if (!retval) |
| 1590 | retval = put_user(0, &infop->si_pid); |
| 1591 | if (!retval) |
| 1592 | retval = put_user(0, &infop->si_uid); |
| 1593 | if (!retval) |
| 1594 | retval = put_user(0, &infop->si_status); |
| 1595 | } |
| 1596 | } |
| 1597 | return retval; |
| 1598 | } |
| 1599 | |
| 1600 | asmlinkage long sys_waitid(int which, pid_t pid, |
| 1601 | struct siginfo __user *infop, int options, |
| 1602 | struct rusage __user *ru) |
| 1603 | { |
| 1604 | long ret; |
| 1605 | |
| 1606 | if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED)) |
| 1607 | return -EINVAL; |
| 1608 | if (!(options & (WEXITED|WSTOPPED|WCONTINUED))) |
| 1609 | return -EINVAL; |
| 1610 | |
| 1611 | switch (which) { |
| 1612 | case P_ALL: |
| 1613 | pid = -1; |
| 1614 | break; |
| 1615 | case P_PID: |
| 1616 | if (pid <= 0) |
| 1617 | return -EINVAL; |
| 1618 | break; |
| 1619 | case P_PGID: |
| 1620 | if (pid <= 0) |
| 1621 | return -EINVAL; |
| 1622 | pid = -pid; |
| 1623 | break; |
| 1624 | default: |
| 1625 | return -EINVAL; |
| 1626 | } |
| 1627 | |
| 1628 | ret = do_wait(pid, options, infop, NULL, ru); |
| 1629 | |
| 1630 | /* avoid REGPARM breakage on x86: */ |
| 1631 | prevent_tail_call(ret); |
| 1632 | return ret; |
| 1633 | } |
| 1634 | |
| 1635 | asmlinkage long sys_wait4(pid_t pid, int __user *stat_addr, |
| 1636 | int options, struct rusage __user *ru) |
| 1637 | { |
| 1638 | long ret; |
| 1639 | |
| 1640 | if (options & ~(WNOHANG|WUNTRACED|WCONTINUED| |
| 1641 | __WNOTHREAD|__WCLONE|__WALL)) |
| 1642 | return -EINVAL; |
| 1643 | ret = do_wait(pid, options | WEXITED, NULL, stat_addr, ru); |
| 1644 | |
| 1645 | /* avoid REGPARM breakage on x86: */ |
| 1646 | prevent_tail_call(ret); |
| 1647 | return ret; |
| 1648 | } |
| 1649 | |
| 1650 | #ifdef __ARCH_WANT_SYS_WAITPID |
| 1651 | |
| 1652 | /* |
| 1653 | * sys_waitpid() remains for compatibility. waitpid() should be |
| 1654 | * implemented by calling sys_wait4() from libc.a. |
| 1655 | */ |
| 1656 | asmlinkage long sys_waitpid(pid_t pid, int __user *stat_addr, int options) |
| 1657 | { |
| 1658 | return sys_wait4(pid, stat_addr, options, NULL); |
| 1659 | } |
| 1660 | |
| 1661 | #endif |