4 * Copyright (C) 1991, 1992 Linus Torvalds
7 #include <linux/config.h>
8 #include <linux/malloc.h>
9 #include <linux/interrupt.h>
10 #include <linux/smp_lock.h>
11 #include <linux/module.h>
12 #ifdef CONFIG_BSD_PROCESS_ACCT
13 #include <linux/acct.h>
16 #include <asm/uaccess.h>
17 #include <asm/pgtable.h>
18 #include <asm/mmu_context.h>
20 extern void sem_exit (void);
21 extern struct task_struct
*child_reaper
;
23 int getrusage(struct task_struct
*, int, struct rusage
*);
25 void release(struct task_struct
* p
)
32 * Wait to make sure the process isn't on the
33 * runqueue (active on some other CPU still)
36 spin_lock_irq(&runqueue_lock
);
38 spin_unlock_irq(&runqueue_lock
);
45 current
->cmin_flt
+= p
->min_flt
+ p
->cmin_flt
;
46 current
->cmaj_flt
+= p
->maj_flt
+ p
->cmaj_flt
;
47 current
->cnswap
+= p
->nswap
+ p
->cnswap
;
49 * Potentially available timeslices are retrieved
50 * here - this way the parent does not get penalized
51 * for creating too many processes.
53 * (this cannot be used to artificially 'generate'
54 * timeslices, because any timeslice recovered here
55 * was given away by the parent in the first place.)
57 current
->counter
+= p
->counter
;
58 if (current
->counter
>= MAX_COUNTER
)
59 current
->counter
= MAX_COUNTER
;
62 printk("task releasing itself\n");
67 * This checks not only the pgrp, but falls back on the pid if no
68 * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
71 int session_of_pgrp(int pgrp
)
73 struct task_struct
*p
;
77 read_lock(&tasklist_lock
);
81 if (p
->pgrp
== pgrp
) {
82 fallback
= p
->session
;
86 fallback
= p
->session
;
88 read_unlock(&tasklist_lock
);
93 * Determine if a process group is "orphaned", according to the POSIX
94 * definition in 2.2.2.52. Orphaned process groups are not to be affected
95 * by terminal-generated stop signals. Newly orphaned process groups are
96 * to receive a SIGHUP and a SIGCONT.
98 * "I ask you, have you ever known what it is to be an orphan?"
100 static int will_become_orphaned_pgrp(int pgrp
, struct task_struct
* ignored_task
)
102 struct task_struct
*p
;
104 read_lock(&tasklist_lock
);
106 if ((p
== ignored_task
) || (p
->pgrp
!= pgrp
) ||
107 (p
->state
== TASK_ZOMBIE
) ||
108 (p
->p_pptr
->pid
== 1))
110 if ((p
->p_pptr
->pgrp
!= pgrp
) &&
111 (p
->p_pptr
->session
== p
->session
)) {
112 read_unlock(&tasklist_lock
);
116 read_unlock(&tasklist_lock
);
117 return 1; /* (sighing) "Often!" */
120 int is_orphaned_pgrp(int pgrp
)
122 return will_become_orphaned_pgrp(pgrp
, 0);
125 static inline int has_stopped_jobs(int pgrp
)
128 struct task_struct
* p
;
130 read_lock(&tasklist_lock
);
134 if (p
->state
!= TASK_STOPPED
)
139 read_unlock(&tasklist_lock
);
143 static inline void forget_original_parent(struct task_struct
* father
)
145 struct task_struct
* p
;
147 read_lock(&tasklist_lock
);
149 if (p
->p_opptr
== father
) {
150 /* We dont want people slaying init */
151 p
->exit_signal
= SIGCHLD
;
153 p
->p_opptr
= child_reaper
; /* init */
154 if (p
->pdeath_signal
) send_sig(p
->pdeath_signal
, p
, 0);
157 read_unlock(&tasklist_lock
);
160 static inline void close_files(struct files_struct
* files
)
168 if (i
>= files
->max_fdset
|| i
>= files
->max_fds
)
170 set
= files
->open_fds
->fds_bits
[j
++];
173 struct file
* file
= xchg(&files
->fd
[i
], NULL
);
175 filp_close(file
, files
);
183 extern kmem_cache_t
*files_cachep
;
185 void put_files_struct(struct files_struct
*files
)
187 if (atomic_dec_and_test(&files
->count
)) {
190 * Free the fd and fdset arrays if we expanded them.
192 if (files
->fd
!= &files
->fd_array
[0])
193 free_fd_array(files
->fd
, files
->max_fds
);
194 if (files
->max_fdset
> __FD_SETSIZE
) {
195 free_fdset(files
->open_fds
, files
->max_fdset
);
196 free_fdset(files
->close_on_exec
, files
->max_fdset
);
198 kmem_cache_free(files_cachep
, files
);
202 static inline void __exit_files(struct task_struct
*tsk
)
204 struct files_struct
* files
= tsk
->files
;
210 put_files_struct(files
);
214 void exit_files(struct task_struct
*tsk
)
218 static inline void __put_fs_struct(struct fs_struct
*fs
)
220 /* No need to hold fs->lock if we are killing it */
221 if (atomic_dec_and_test(&fs
->count
)) {
228 mntput(fs
->altrootmnt
);
234 void put_fs_struct(struct fs_struct
*fs
)
239 static inline void __exit_fs(struct task_struct
*tsk
)
241 struct fs_struct
* fs
= tsk
->fs
;
251 void exit_fs(struct task_struct
*tsk
)
256 static inline void __exit_sighand(struct task_struct
*tsk
)
258 struct signal_struct
* sig
= tsk
->sig
;
261 spin_lock_irq(&tsk
->sigmask_lock
);
263 spin_unlock_irq(&tsk
->sigmask_lock
);
264 if (atomic_dec_and_test(&sig
->count
))
271 void exit_sighand(struct task_struct
*tsk
)
277 * We can use these to temporarily drop into
278 * "lazy TLB" mode and back.
280 struct mm_struct
* start_lazy_tlb(void)
282 struct mm_struct
*mm
= current
->mm
;
284 /* active_mm is still 'mm' */
285 atomic_inc(&mm
->mm_count
);
286 enter_lazy_tlb(mm
, current
, smp_processor_id());
290 void end_lazy_tlb(struct mm_struct
*mm
)
292 struct mm_struct
*active_mm
= current
->active_mm
;
295 if (mm
!= active_mm
) {
296 current
->active_mm
= mm
;
297 activate_mm(active_mm
, mm
);
303 * Turn us into a lazy TLB process if we
306 static inline void __exit_mm(struct task_struct
* tsk
)
308 struct mm_struct
* mm
= tsk
->mm
;
311 atomic_inc(&mm
->mm_count
);
313 if (mm
!= tsk
->active_mm
) BUG();
314 /* more a memory barrier than a real lock */
318 enter_lazy_tlb(mm
, current
, smp_processor_id());
323 void exit_mm(struct task_struct
*tsk
)
329 * Send signals to all our closest relatives so that they know
330 * to properly mourn us..
332 static void exit_notify(void)
334 struct task_struct
* p
, *t
;
336 forget_original_parent(current
);
338 * Check to see if any process groups have become orphaned
339 * as a result of our exiting, and if they have any stopped
340 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
342 * Case i: Our father is in a different pgrp than we are
343 * and we were the only connection outside, so our pgrp
344 * is about to become orphaned.
349 if ((t
->pgrp
!= current
->pgrp
) &&
350 (t
->session
== current
->session
) &&
351 will_become_orphaned_pgrp(current
->pgrp
, current
) &&
352 has_stopped_jobs(current
->pgrp
)) {
353 kill_pg(current
->pgrp
,SIGHUP
,1);
354 kill_pg(current
->pgrp
,SIGCONT
,1);
357 /* Let father know we died
359 * Thread signals are configurable, but you aren't going to use
360 * that to send signals to arbitary processes.
361 * That stops right now.
363 * If the parent exec id doesn't match the exec id we saved
364 * when we started then we know the parent has changed security
367 * If our self_exec id doesn't match our parent_exec_id then
368 * we have changed execution domain as these two values started
369 * the same after a fork.
373 if(current
->exit_signal
!= SIGCHLD
&&
374 ( current
->parent_exec_id
!= t
->self_exec_id
||
375 current
->self_exec_id
!= current
->parent_exec_id
)
376 && !capable(CAP_KILL
))
377 current
->exit_signal
= SIGCHLD
;
379 notify_parent(current
, current
->exit_signal
);
382 * This loop does two things:
384 * A. Make init inherit all the child processes
385 * B. Check to see if any process groups have become orphaned
386 * as a result of our exiting, and if they have any stopped
387 * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
390 write_lock_irq(&tasklist_lock
);
391 while (current
->p_cptr
!= NULL
) {
393 current
->p_cptr
= p
->p_osptr
;
397 p
->p_pptr
= p
->p_opptr
;
398 p
->p_osptr
= p
->p_pptr
->p_cptr
;
400 p
->p_osptr
->p_ysptr
= p
;
401 p
->p_pptr
->p_cptr
= p
;
402 if (p
->state
== TASK_ZOMBIE
)
403 notify_parent(p
, p
->exit_signal
);
405 * process group orphan check
406 * Case ii: Our child is in a different pgrp
407 * than we are, and it was the only connection
408 * outside, so the child pgrp is now orphaned.
410 if ((p
->pgrp
!= current
->pgrp
) &&
411 (p
->session
== current
->session
)) {
414 write_unlock_irq(&tasklist_lock
);
415 if (is_orphaned_pgrp(pgrp
) && has_stopped_jobs(pgrp
)) {
416 kill_pg(pgrp
,SIGHUP
,1);
417 kill_pg(pgrp
,SIGCONT
,1);
419 write_lock_irq(&tasklist_lock
);
422 write_unlock_irq(&tasklist_lock
);
425 disassociate_ctty(1);
428 NORET_TYPE
void do_exit(long code
)
430 struct task_struct
*tsk
= current
;
433 printk("Aiee, killing interrupt handler\n");
435 panic("Attempted to kill the idle task!");
437 panic("Attempted to kill init!");
438 tsk
->flags
|= PF_EXITING
;
439 del_timer_sync(&tsk
->real_timer
);
442 #ifdef CONFIG_BSD_PROCESS_ACCT
452 tsk
->state
= TASK_ZOMBIE
;
453 tsk
->exit_code
= code
;
455 put_exec_domain(tsk
->exec_domain
);
456 if (tsk
->binfmt
&& tsk
->binfmt
->module
)
457 __MOD_DEC_USE_COUNT(tsk
->binfmt
->module
);
460 * In order to get rid of the "volatile function does return" message
461 * I did this little loop that confuses gcc to think do_exit really
462 * is volatile. In fact it's schedule() that is volatile in some
463 * circumstances: when current->state = ZOMBIE, schedule() never
466 * In fact the natural way to do all this is to have the label and the
467 * goto right after each other, but I put the fake_volatile label at
468 * the start of the function just in case something /really/ bad
469 * happens, and the schedule returns. This way we can try again. I'm
470 * not paranoid: it's just that everybody is out to get me.
475 asmlinkage
long sys_exit(int error_code
)
477 do_exit((error_code
&0xff)<<8);
480 asmlinkage
long sys_wait4(pid_t pid
,unsigned int * stat_addr
, int options
, struct rusage
* ru
)
483 DECLARE_WAITQUEUE(wait
, current
);
484 struct task_struct
*p
;
486 if (options
& ~(WNOHANG
|WUNTRACED
|__WCLONE
|__WALL
))
489 add_wait_queue(¤t
->wait_chldexit
,&wait
);
492 current
->state
= TASK_INTERRUPTIBLE
;
493 read_lock(&tasklist_lock
);
494 for (p
= current
->p_cptr
; p
; p
= p
->p_osptr
) {
499 if (p
->pgrp
!= current
->pgrp
)
501 } else if (pid
!= -1) {
505 /* Wait for all children (clone and not) if __WALL is set;
506 * otherwise, wait for clone children *only* if __WCLONE is
507 * set; otherwise, wait for non-clone children *only*. (Note:
508 * A "clone" child here is one that reports to its parent
509 * using a signal other than SIGCHLD.) */
510 if (((p
->exit_signal
!= SIGCHLD
) ^ ((options
& __WCLONE
) != 0))
511 && !(options
& __WALL
))
518 if (!(options
& WUNTRACED
) && !(p
->ptrace
& PT_PTRACED
))
520 read_unlock(&tasklist_lock
);
521 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
522 if (!retval
&& stat_addr
)
523 retval
= put_user((p
->exit_code
<< 8) | 0x7f, stat_addr
);
530 current
->times
.tms_cutime
+= p
->times
.tms_utime
+ p
->times
.tms_cutime
;
531 current
->times
.tms_cstime
+= p
->times
.tms_stime
+ p
->times
.tms_cstime
;
532 read_unlock(&tasklist_lock
);
533 retval
= ru
? getrusage(p
, RUSAGE_BOTH
, ru
) : 0;
534 if (!retval
&& stat_addr
)
535 retval
= put_user(p
->exit_code
, stat_addr
);
539 if (p
->p_opptr
!= p
->p_pptr
) {
540 write_lock_irq(&tasklist_lock
);
542 p
->p_pptr
= p
->p_opptr
;
544 write_unlock_irq(&tasklist_lock
);
545 notify_parent(p
, SIGCHLD
);
553 read_unlock(&tasklist_lock
);
556 if (options
& WNOHANG
)
558 retval
= -ERESTARTSYS
;
559 if (signal_pending(current
))
566 current
->state
= TASK_RUNNING
;
567 remove_wait_queue(¤t
->wait_chldexit
,&wait
);
571 #if !defined(__alpha__) && !defined(__ia64__)
574 * sys_waitpid() remains for compatibility. waitpid() should be
575 * implemented by calling sys_wait4() from libc.a.
577 asmlinkage
long sys_waitpid(pid_t pid
,unsigned int * stat_addr
, int options
)
579 return sys_wait4(pid
, stat_addr
, options
, NULL
);