#include <linux/pid_namespace.h>
#include <linux/ptrace.h>
#include <linux/profile.h>
-#include <linux/signalfd.h>
#include <linux/mount.h>
#include <linux/proc_fs.h>
#include <linux/kthread.h>
#include <linux/mempolicy.h>
#include <linux/taskstats_kern.h>
#include <linux/delayacct.h>
-#include <linux/cpuset.h>
+#include <linux/freezer.h>
+#include <linux/cgroup.h>
#include <linux/syscalls.h>
#include <linux/signal.h>
#include <linux/posix-timers.h>
#include <asm/pgtable.h>
#include <asm/mmu_context.h>
-extern void sem_exit (void);
-
static void exit_mm(struct task_struct * tsk);
static void __unhash_process(struct task_struct *p)
sighand = rcu_dereference(tsk->sighand);
spin_lock(&sighand->siglock);
- /*
- * Notify that this sighand has been detached. This must
- * be called with the tsk->sighand lock held. Also, this
- * access tsk->sighand internally, so it must be called
- * before tsk->sighand is reset.
- */
- signalfd_detach_locked(tsk);
-
posix_cpu_timers_exit(tsk);
if (atomic_dec_and_test(&sig->count))
posix_cpu_timers_exit_group(tsk);
* If there is any task waiting for the group exit
* then notify it:
*/
- if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count) {
+ if (sig->group_exit_task && atomic_read(&sig->count) == sig->notify_count)
wake_up_process(sig->group_exit_task);
- sig->group_exit_task = NULL;
- }
+
if (tsk == sig->curr_target)
sig->curr_target = next_thread(tsk);
/*
*/
sig->utime = cputime_add(sig->utime, tsk->utime);
sig->stime = cputime_add(sig->stime, tsk->stime);
+ sig->gtime = cputime_add(sig->gtime, tsk->gtime);
sig->min_flt += tsk->min_flt;
sig->maj_flt += tsk->maj_flt;
sig->nvcsw += tsk->nvcsw;
sig->nivcsw += tsk->nivcsw;
- sig->sched_time += tsk->sched_time;
sig->inblock += task_io_get_inblock(tsk);
sig->oublock += task_io_get_oublock(tsk);
+ sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
sig = NULL; /* Marker for below. */
}
int zap_leader;
repeat:
atomic_dec(&p->user->processes);
+ proc_flush_task(p);
write_lock_irq(&tasklist_lock);
ptrace_unlink(p);
BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children));
zap_leader = (leader->exit_signal == -1);
}
- sched_exit(p);
write_unlock_irq(&tasklist_lock);
- proc_flush_task(p);
release_thread(p);
call_rcu(&p->rcu, delayed_put_task_struct);
static int will_become_orphaned_pgrp(struct pid *pgrp, struct task_struct *ignored_task)
{
struct task_struct *p;
- int ret = 1;
do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
- if (p == ignored_task
- || p->exit_state
- || is_init(p->real_parent))
+ if ((p == ignored_task) ||
+ (p->exit_state && thread_group_empty(p)) ||
+ is_global_init(p->real_parent))
continue;
+
if (task_pgrp(p->real_parent) != pgrp &&
- task_session(p->real_parent) == task_session(p)) {
- ret = 0;
- break;
- }
+ task_session(p->real_parent) == task_session(p))
+ return 0;
} while_each_pid_task(pgrp, PIDTYPE_PGID, p);
- return ret; /* (sighing) "Often!" */
+
+ return 1;
}
int is_current_pgrp_orphaned(void)
struct task_struct *p;
do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
- if (p->state != TASK_STOPPED)
+ if (!task_is_stopped(p))
continue;
retval = 1;
break;
return retval;
}
+/*
+ * Check to see if any process groups have become orphaned as
+ * a result of our exiting, and if they have any stopped jobs,
+ * send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
+ */
+static void
+kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent)
+{
+ struct pid *pgrp = task_pgrp(tsk);
+ struct task_struct *ignored_task = tsk;
+
+ if (!parent)
+ /* exit: our father is in a different pgrp than
+ * we are and we were the only connection outside.
+ */
+ parent = tsk->real_parent;
+ else
+ /* reparent: our child is in a different pgrp than
+ * we are, and it was the only connection outside.
+ */
+ ignored_task = NULL;
+
+ if (task_pgrp(parent) != pgrp &&
+ task_session(parent) == task_session(tsk) &&
+ will_become_orphaned_pgrp(pgrp, ignored_task) &&
+ has_stopped_jobs(pgrp)) {
+ __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
+ __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
+ }
+}
+
/**
* reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
*
/* Set the exit signal to SIGCHLD so we signal init on exit */
current->exit_signal = SIGCHLD;
- if (!has_rt_policy(current) && (task_nice(current) < 0))
+ if (task_nice(current) < 0)
set_user_nice(current, 0);
/* cpus_allowed? */
/* rt_priority? */
switch_uid(INIT_USER);
}
-void __set_special_pids(pid_t session, pid_t pgrp)
+void __set_special_pids(struct pid *pid)
{
struct task_struct *curr = current->group_leader;
+ pid_t nr = pid_nr(pid);
- if (process_session(curr) != session) {
+ if (task_session(curr) != pid) {
detach_pid(curr, PIDTYPE_SID);
- set_signal_session(curr->signal, session);
- attach_pid(curr, PIDTYPE_SID, find_pid(session));
+ attach_pid(curr, PIDTYPE_SID, pid);
+ set_task_session(curr, nr);
}
- if (process_group(curr) != pgrp) {
+ if (task_pgrp(curr) != pid) {
detach_pid(curr, PIDTYPE_PGID);
- curr->signal->pgrp = pgrp;
- attach_pid(curr, PIDTYPE_PGID, find_pid(pgrp));
+ attach_pid(curr, PIDTYPE_PGID, pid);
+ set_task_pgrp(curr, nr);
}
}
-static void set_special_pids(pid_t session, pid_t pgrp)
+static void set_special_pids(struct pid *pid)
{
write_lock_irq(&tasklist_lock);
- __set_special_pids(session, pgrp);
+ __set_special_pids(pid);
write_unlock_irq(&tasklist_lock);
}
* they would be locked into memory.
*/
exit_mm(current);
+ /*
+ * We don't want to have TIF_FREEZE set if the system-wide hibernation
+ * or suspend transition begins right now.
+ */
+ current->flags |= PF_NOFREEZE;
- set_special_pids(1, 1);
+ if (current->nsproxy != &init_nsproxy) {
+ get_nsproxy(&init_nsproxy);
+ switch_task_namespaces(current, &init_nsproxy);
+ }
+ set_special_pids(&init_struct_pid);
proc_clear_tty(current);
/* Block and flush all signals */
current->fs = fs;
atomic_inc(&fs->count);
- exit_task_namespaces(current);
- current->nsproxy = init_task.nsproxy;
- get_task_namespaces(current);
-
- exit_files(current);
+ exit_files(current);
current->files = init_task.files;
atomic_inc(¤t->files->count);
return files;
}
-void fastcall put_files_struct(struct files_struct *files)
+void put_files_struct(struct files_struct *files)
{
struct fdtable *fdt;
}
}
-EXPORT_SYMBOL(put_files_struct);
-
-void reset_files_struct(struct task_struct *tsk, struct files_struct *files)
+void reset_files_struct(struct files_struct *files)
{
+ struct task_struct *tsk = current;
struct files_struct *old;
old = tsk->files;
task_unlock(tsk);
put_files_struct(old);
}
-EXPORT_SYMBOL(reset_files_struct);
-static inline void __exit_files(struct task_struct *tsk)
+void exit_files(struct task_struct *tsk)
{
struct files_struct * files = tsk->files;
}
}
-void exit_files(struct task_struct *tsk)
-{
- __exit_files(tsk);
-}
-
-static inline void __put_fs_struct(struct fs_struct *fs)
+void put_fs_struct(struct fs_struct *fs)
{
/* No need to hold fs->lock if we are killing it */
if (atomic_dec_and_test(&fs->count)) {
- dput(fs->root);
- mntput(fs->rootmnt);
- dput(fs->pwd);
- mntput(fs->pwdmnt);
- if (fs->altroot) {
- dput(fs->altroot);
- mntput(fs->altrootmnt);
- }
+ path_put(&fs->root);
+ path_put(&fs->pwd);
+ if (fs->altroot.dentry)
+ path_put(&fs->altroot);
kmem_cache_free(fs_cachep, fs);
}
}
-void put_fs_struct(struct fs_struct *fs)
-{
- __put_fs_struct(fs);
-}
-
-static inline void __exit_fs(struct task_struct *tsk)
+void exit_fs(struct task_struct *tsk)
{
struct fs_struct * fs = tsk->fs;
task_lock(tsk);
tsk->fs = NULL;
task_unlock(tsk);
- __put_fs_struct(fs);
+ put_fs_struct(fs);
}
}
-void exit_fs(struct task_struct *tsk)
+EXPORT_SYMBOL_GPL(exit_fs);
+
+#ifdef CONFIG_MM_OWNER
+/*
+ * Task p is exiting and it owned mm, lets find a new owner for it
+ */
+static inline int
+mm_need_new_owner(struct mm_struct *mm, struct task_struct *p)
{
- __exit_fs(tsk);
+ /*
+ * If there are other users of the mm and the owner (us) is exiting
+ * we need to find a new owner to take on the responsibility.
+ */
+ if (!mm)
+ return 0;
+ if (atomic_read(&mm->mm_users) <= 1)
+ return 0;
+ if (mm->owner != p)
+ return 0;
+ return 1;
}
-EXPORT_SYMBOL_GPL(exit_fs);
+void mm_update_next_owner(struct mm_struct *mm)
+{
+ struct task_struct *c, *g, *p = current;
+
+retry:
+ if (!mm_need_new_owner(mm, p))
+ return;
+
+ read_lock(&tasklist_lock);
+ /*
+ * Search in the children
+ */
+ list_for_each_entry(c, &p->children, sibling) {
+ if (c->mm == mm)
+ goto assign_new_owner;
+ }
+
+ /*
+ * Search in the siblings
+ */
+ list_for_each_entry(c, &p->parent->children, sibling) {
+ if (c->mm == mm)
+ goto assign_new_owner;
+ }
+
+ /*
+ * Search through everything else. We should not get
+ * here often
+ */
+ do_each_thread(g, c) {
+ if (c->mm == mm)
+ goto assign_new_owner;
+ } while_each_thread(g, c);
+
+ read_unlock(&tasklist_lock);
+ return;
+
+assign_new_owner:
+ BUG_ON(c == p);
+ get_task_struct(c);
+ /*
+ * The task_lock protects c->mm from changing.
+ * We always want mm->owner->mm == mm
+ */
+ task_lock(c);
+ /*
+ * Delay read_unlock() till we have the task_lock()
+ * to ensure that c does not slip away underneath us
+ */
+ read_unlock(&tasklist_lock);
+ if (c->mm != mm) {
+ task_unlock(c);
+ put_task_struct(c);
+ goto retry;
+ }
+ cgroup_mm_owner_callbacks(mm->owner, c);
+ mm->owner = c;
+ task_unlock(c);
+ put_task_struct(c);
+}
+#endif /* CONFIG_MM_OWNER */
/*
* Turn us into a lazy TLB process if we
tsk->mm = NULL;
up_read(&mm->mmap_sem);
enter_lazy_tlb(mm, current);
+ /* We don't want this task to be frozen prematurely */
+ clear_freeze_flag(tsk);
task_unlock(tsk);
+ mm_update_next_owner(mm);
mmput(mm);
}
-static inline void
-choose_new_parent(struct task_struct *p, struct task_struct *reaper)
-{
- /*
- * Make sure we're not reparenting to ourselves and that
- * the parent is not a zombie.
- */
- BUG_ON(p == reaper || reaper->exit_state);
- p->real_parent = reaper;
-}
-
static void
reparent_thread(struct task_struct *p, struct task_struct *father, int traced)
{
p->parent = p->real_parent;
add_parent(p);
- if (p->state == TASK_TRACED) {
+ if (task_is_traced(p)) {
/*
* If it was at a trace stop, turn it into
* a normal stop since it's no longer being
p->exit_signal != -1 && thread_group_empty(p))
do_notify_parent(p, p->exit_signal);
- /*
- * process group orphan check
- * Case ii: Our child is in a different pgrp
- * than we are, and it was the only connection
- * outside, so the child pgrp is now orphaned.
- */
- if ((task_pgrp(p) != task_pgrp(father)) &&
- (task_session(p) == task_session(father))) {
- struct pid *pgrp = task_pgrp(p);
-
- if (will_become_orphaned_pgrp(pgrp, NULL) &&
- has_stopped_jobs(pgrp)) {
- __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
- __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
- }
- }
+ kill_orphaned_pgrp(p, father);
}
/*
* the child reaper process (ie "init") in our pid
* space.
*/
-static void
-forget_original_parent(struct task_struct *father, struct list_head *to_release)
+static void forget_original_parent(struct task_struct *father)
{
- struct task_struct *p, *reaper = father;
- struct list_head *_p, *_n;
+ struct task_struct *p, *n, *reaper = father;
+ struct list_head ptrace_dead;
+
+ INIT_LIST_HEAD(&ptrace_dead);
+
+ write_lock_irq(&tasklist_lock);
do {
reaper = next_thread(reaper);
if (reaper == father) {
- reaper = child_reaper(father);
+ reaper = task_child_reaper(father);
break;
}
- } while (reaper->exit_state);
+ } while (reaper->flags & PF_EXITING);
/*
* There are only two places where our children can be:
*
* Search them and reparent children.
*/
- list_for_each_safe(_p, _n, &father->children) {
+ list_for_each_entry_safe(p, n, &father->children, sibling) {
int ptrace;
- p = list_entry(_p, struct task_struct, sibling);
ptrace = p->ptrace;
if (father == p->real_parent) {
/* reparent with a reaper, real father it's us */
- choose_new_parent(p, reaper);
+ p->real_parent = reaper;
reparent_thread(p, father, 0);
} else {
/* reparent ptraced task to its real parent */
* while it was being traced by us, to be able to see it in wait4.
*/
if (unlikely(ptrace && p->exit_state == EXIT_ZOMBIE && p->exit_signal == -1))
- list_add(&p->ptrace_list, to_release);
+ list_add(&p->ptrace_list, &ptrace_dead);
}
- list_for_each_safe(_p, _n, &father->ptrace_children) {
- p = list_entry(_p, struct task_struct, ptrace_list);
- choose_new_parent(p, reaper);
+
+ list_for_each_entry_safe(p, n, &father->ptrace_children, ptrace_list) {
+ p->real_parent = reaper;
reparent_thread(p, father, 1);
}
+
+ write_unlock_irq(&tasklist_lock);
+ BUG_ON(!list_empty(&father->children));
+ BUG_ON(!list_empty(&father->ptrace_children));
+
+ list_for_each_entry_safe(p, n, &ptrace_dead, ptrace_list) {
+ list_del_init(&p->ptrace_list);
+ release_task(p);
+ }
+
}
/*
* Send signals to all our closest relatives so that they know
* to properly mourn us..
*/
-static void exit_notify(struct task_struct *tsk)
+static void exit_notify(struct task_struct *tsk, int group_dead)
{
int state;
- struct task_struct *t;
- struct list_head ptrace_dead, *_p, *_n;
- struct pid *pgrp;
-
- if (signal_pending(tsk) && !(tsk->signal->flags & SIGNAL_GROUP_EXIT)
- && !thread_group_empty(tsk)) {
- /*
- * This occurs when there was a race between our exit
- * syscall and a group signal choosing us as the one to
- * wake up. It could be that we are the only thread
- * alerted to check for pending signals, but another thread
- * should be woken now to take the signal since we will not.
- * Now we'll wake all the threads in the group just to make
- * sure someone gets all the pending signals.
- */
- read_lock(&tasklist_lock);
- spin_lock_irq(&tsk->sighand->siglock);
- for (t = next_thread(tsk); t != tsk; t = next_thread(t))
- if (!signal_pending(t) && !(t->flags & PF_EXITING))
- recalc_sigpending_and_wake(t);
- spin_unlock_irq(&tsk->sighand->siglock);
- read_unlock(&tasklist_lock);
- }
-
- write_lock_irq(&tasklist_lock);
/*
* This does two things:
* as a result of our exiting, and if they have any stopped
* jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
*/
+ forget_original_parent(tsk);
+ exit_task_namespaces(tsk);
- INIT_LIST_HEAD(&ptrace_dead);
- forget_original_parent(tsk, &ptrace_dead);
- BUG_ON(!list_empty(&tsk->children));
- BUG_ON(!list_empty(&tsk->ptrace_children));
-
- /*
- * Check to see if any process groups have become orphaned
- * as a result of our exiting, and if they have any stopped
- * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
- *
- * Case i: Our father is in a different pgrp than we are
- * and we were the only connection outside, so our pgrp
- * is about to become orphaned.
- */
-
- t = tsk->real_parent;
-
- pgrp = task_pgrp(tsk);
- if ((task_pgrp(t) != pgrp) &&
- (task_session(t) == task_session(tsk)) &&
- will_become_orphaned_pgrp(pgrp, tsk) &&
- has_stopped_jobs(pgrp)) {
- __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
- __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
- }
+ write_lock_irq(&tasklist_lock);
+ if (group_dead)
+ kill_orphaned_pgrp(tsk->group_leader, NULL);
- /* Let father know we died
+ /* Let father know we died
*
* Thread signals are configurable, but you aren't going to use
- * that to send signals to arbitary processes.
+ * that to send signals to arbitary processes.
* That stops right now.
*
* If the parent exec id doesn't match the exec id we saved
* If our self_exec id doesn't match our parent_exec_id then
* we have changed execution domain as these two values started
* the same after a fork.
- *
*/
-
if (tsk->exit_signal != SIGCHLD && tsk->exit_signal != -1 &&
- ( tsk->parent_exec_id != t->self_exec_id ||
- tsk->self_exec_id != tsk->parent_exec_id)
+ (tsk->parent_exec_id != tsk->real_parent->self_exec_id ||
+ tsk->self_exec_id != tsk->parent_exec_id)
&& !capable(CAP_KILL))
tsk->exit_signal = SIGCHLD;
}
state = EXIT_ZOMBIE;
- if (tsk->exit_signal == -1 &&
- (likely(tsk->ptrace == 0) ||
- unlikely(tsk->parent->signal->flags & SIGNAL_GROUP_EXIT)))
+ if (tsk->exit_signal == -1 && likely(!tsk->ptrace))
state = EXIT_DEAD;
tsk->exit_state = state;
- write_unlock_irq(&tasklist_lock);
+ if (thread_group_leader(tsk) &&
+ tsk->signal->notify_count < 0 &&
+ tsk->signal->group_exit_task)
+ wake_up_process(tsk->signal->group_exit_task);
- list_for_each_safe(_p, _n, &ptrace_dead) {
- list_del_init(_p);
- t = list_entry(_p, struct task_struct, ptrace_list);
- release_task(t);
- }
+ write_unlock_irq(&tasklist_lock);
/* If the process is dead, release it - nobody will wait for it */
if (state == EXIT_DEAD)
release_task(tsk);
}
-fastcall NORET_TYPE void do_exit(long code)
+#ifdef CONFIG_DEBUG_STACK_USAGE
+static void check_stack_usage(void)
+{
+ static DEFINE_SPINLOCK(low_water_lock);
+ static int lowest_to_date = THREAD_SIZE;
+ unsigned long *n = end_of_stack(current);
+ unsigned long free;
+
+ while (*n == 0)
+ n++;
+ free = (unsigned long)n - (unsigned long)end_of_stack(current);
+
+ if (free >= lowest_to_date)
+ return;
+
+ spin_lock(&low_water_lock);
+ if (free < lowest_to_date) {
+ printk(KERN_WARNING "%s used greatest stack depth: %lu bytes "
+ "left\n",
+ current->comm, free);
+ lowest_to_date = free;
+ }
+ spin_unlock(&low_water_lock);
+}
+#else
+static inline void check_stack_usage(void) {}
+#endif
+
+static inline void exit_child_reaper(struct task_struct *tsk)
+{
+ if (likely(tsk->group_leader != task_child_reaper(tsk)))
+ return;
+
+ if (tsk->nsproxy->pid_ns == &init_pid_ns)
+ panic("Attempted to kill init!");
+
+ /*
+ * @tsk is the last thread in the 'cgroup-init' and is exiting.
+ * Terminate all remaining processes in the namespace and reap them
+ * before exiting @tsk.
+ *
+ * Note that @tsk (last thread of cgroup-init) may not necessarily
+ * be the child-reaper (i.e main thread of cgroup-init) of the
+ * namespace i.e the child_reaper may have already exited.
+ *
+ * Even after a child_reaper exits, we let it inherit orphaned children,
+ * because, pid_ns->child_reaper remains valid as long as there is
+ * at least one living sub-thread in the cgroup init.
+
+ * This living sub-thread of the cgroup-init will be notified when
+ * a child inherited by the 'child-reaper' exits (do_notify_parent()
+ * uses __group_send_sig_info()). Further, when reaping child processes,
+ * do_wait() iterates over children of all living sub threads.
+
+ * i.e even though 'child_reaper' thread is listed as the parent of the
+ * orphaned children, any living sub-thread in the cgroup-init can
+ * perform the role of the child_reaper.
+ */
+ zap_pid_ns_processes(tsk->nsproxy->pid_ns);
+}
+
+NORET_TYPE void do_exit(long code)
{
struct task_struct *tsk = current;
int group_dead;
panic("Aiee, killing interrupt handler!");
if (unlikely(!tsk->pid))
panic("Attempted to kill the idle task!");
- if (unlikely(tsk == child_reaper(tsk))) {
- if (tsk->nsproxy->pid_ns != &init_pid_ns)
- tsk->nsproxy->pid_ns->child_reaper = init_pid_ns.child_reaper;
- else
- panic("Attempted to kill init!");
- }
-
if (unlikely(current->ptrace & PT_TRACE_EXIT)) {
current->ptrace_message = code;
if (unlikely(tsk->flags & PF_EXITING)) {
printk(KERN_ALERT
"Fixing recursive fault but reboot is needed!\n");
+ /*
+ * We can do this unlocked here. The futex code uses
+ * this flag just to verify whether the pi state
+ * cleanup has been done or not. In the worst case it
+ * loops once more. We pretend that the cleanup was
+ * done as there is no way to return. Either the
+ * OWNER_DIED bit is set by now or we push the blocked
+ * task into the wait for ever nirwana as well.
+ */
+ tsk->flags |= PF_EXITPIDONE;
if (tsk->io_context)
exit_io_context();
set_current_state(TASK_UNINTERRUPTIBLE);
schedule();
}
- tsk->flags |= PF_EXITING;
+ exit_signals(tsk); /* sets PF_EXITING */
+ /*
+ * tsk->flags are checked in the futex code to protect against
+ * an exiting task cleaning up the robust pi futexes.
+ */
+ smp_mb();
+ spin_unlock_wait(&tsk->pi_lock);
if (unlikely(in_atomic()))
printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n",
- current->comm, current->pid,
+ current->comm, task_pid_nr(current),
preempt_count());
acct_update_integrals(tsk);
}
group_dead = atomic_dec_and_test(&tsk->signal->live);
if (group_dead) {
- hrtimer_cancel(&tsk->signal->real_timer);
+ exit_child_reaper(tsk);
+ hrtimer_cancel(&tsk->signal->real_timer);
exit_itimers(tsk->signal);
}
acct_collect(code, group_dead);
+#ifdef CONFIG_FUTEX
if (unlikely(tsk->robust_list))
exit_robust_list(tsk);
-#if defined(CONFIG_FUTEX) && defined(CONFIG_COMPAT)
+#ifdef CONFIG_COMPAT
if (unlikely(tsk->compat_robust_list))
compat_exit_robust_list(tsk);
#endif
+#endif
+ if (group_dead)
+ tty_audit_exit();
if (unlikely(tsk->audit_context))
audit_free(tsk);
+ tsk->exit_code = code;
taskstats_exit(tsk, group_dead);
exit_mm(tsk);
if (group_dead)
acct_process();
exit_sem(tsk);
- __exit_files(tsk);
- __exit_fs(tsk);
+ exit_files(tsk);
+ exit_fs(tsk);
+ check_stack_usage();
exit_thread();
- cpuset_exit(tsk);
+ cgroup_exit(tsk, 1);
exit_keys(tsk);
if (group_dead && tsk->signal->leader)
if (tsk->binfmt)
module_put(tsk->binfmt->module);
- tsk->exit_code = code;
proc_exit_connector(tsk);
- exit_task_namespaces(tsk);
- exit_notify(tsk);
+ exit_notify(tsk, group_dead);
#ifdef CONFIG_NUMA
- mpol_free(tsk->mempolicy);
+ mpol_put(tsk->mempolicy);
tsk->mempolicy = NULL;
#endif
+#ifdef CONFIG_FUTEX
/*
* This must happen late, after the PID is not
* hashed anymore:
exit_pi_state_list(tsk);
if (unlikely(current->pi_state_cache))
kfree(current->pi_state_cache);
+#endif
/*
* Make sure we are holding no locks:
*/
debug_check_no_locks_held(tsk);
+ /*
+ * We can do this unlocked here. The futex code uses this flag
+ * just to verify whether the pi state cleanup has been done
+ * or not. In the worst case it loops once more.
+ */
+ tsk->flags |= PF_EXITPIDONE;
if (tsk->io_context)
exit_io_context();
struct signal_struct *const sig = current->signal;
struct sighand_struct *const sighand = current->sighand;
spin_lock_irq(&sighand->siglock);
- if (sig->flags & SIGNAL_GROUP_EXIT)
+ if (signal_group_exit(sig))
/* Another thread got here before we took the lock. */
exit_code = sig->group_exit_code;
else {
sig->group_exit_code = exit_code;
+ sig->flags = SIGNAL_GROUP_EXIT;
zap_other_threads(current);
}
spin_unlock_irq(&sighand->siglock);
do_group_exit((error_code & 0xff) << 8);
}
-static int eligible_child(pid_t pid, int options, struct task_struct *p)
+static struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
+{
+ struct pid *pid = NULL;
+ if (type == PIDTYPE_PID)
+ pid = task->pids[type].pid;
+ else if (type < PIDTYPE_MAX)
+ pid = task->group_leader->pids[type].pid;
+ return pid;
+}
+
+static int eligible_child(enum pid_type type, struct pid *pid, int options,
+ struct task_struct *p)
{
int err;
- if (pid > 0) {
- if (p->pid != pid)
- return 0;
- } else if (!pid) {
- if (process_group(p) != process_group(current))
- return 0;
- } else if (pid != -1) {
- if (process_group(p) != -pid)
+ if (type < PIDTYPE_MAX) {
+ if (task_pid_type(p, type) != pid)
return 0;
}
if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0))
&& !(options & __WALL))
return 0;
- /*
- * Do not consider thread group leaders that are
- * in a non-empty thread group:
- */
- if (delay_group_leader(p))
- return 2;
err = security_task_wait(p);
- if (err)
- return err;
+ if (likely(!err))
+ return 1;
- return 1;
+ if (type != PIDTYPE_PID)
+ return 0;
+ /* This child was explicitly requested, abort */
+ read_unlock(&tasklist_lock);
+ return err;
}
static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid,
int __user *stat_addr, struct rusage __user *ru)
{
unsigned long state;
- int retval;
- int status;
+ int retval, status, traced;
+ pid_t pid = task_pid_vnr(p);
if (unlikely(noreap)) {
- pid_t pid = p->pid;
uid_t uid = p->uid;
int exit_code = p->exit_code;
int why, status;
- if (unlikely(p->exit_state != EXIT_ZOMBIE))
- return 0;
- if (unlikely(p->exit_signal == -1 && p->ptrace == 0))
- return 0;
get_task_struct(p);
read_unlock(&tasklist_lock);
if ((exit_code & 0x7f) == 0) {
BUG_ON(state != EXIT_DEAD);
return 0;
}
- if (unlikely(p->exit_signal == -1 && p->ptrace == 0)) {
- /*
- * This can only happen in a race with a ptraced thread
- * dying on another processor.
- */
- return 0;
- }
- if (likely(p->real_parent == p->parent) && likely(p->signal)) {
+ /* traced means p->ptrace, but not vice versa */
+ traced = (p->real_parent != p->parent);
+
+ if (likely(!traced)) {
struct signal_struct *psig;
struct signal_struct *sig;
cputime_add(p->stime,
cputime_add(sig->stime,
sig->cstime)));
+ psig->cgtime =
+ cputime_add(psig->cgtime,
+ cputime_add(p->gtime,
+ cputime_add(sig->gtime,
+ sig->cgtime)));
psig->cmin_flt +=
p->min_flt + sig->min_flt + sig->cmin_flt;
psig->cmaj_flt +=
retval = put_user(status, &infop->si_status);
}
if (!retval && infop)
- retval = put_user(p->pid, &infop->si_pid);
+ retval = put_user(pid, &infop->si_pid);
if (!retval && infop)
retval = put_user(p->uid, &infop->si_uid);
- if (retval) {
- // TODO: is this safe?
- p->exit_state = EXIT_ZOMBIE;
- return retval;
- }
- retval = p->pid;
- if (p->real_parent != p->parent) {
+ if (!retval)
+ retval = pid;
+
+ if (traced) {
write_lock_irq(&tasklist_lock);
- /* Double-check with lock held. */
- if (p->real_parent != p->parent) {
- __ptrace_unlink(p);
- // TODO: is this safe?
- p->exit_state = EXIT_ZOMBIE;
- /*
- * If this is not a detached task, notify the parent.
- * If it's still not detached after that, don't release
- * it now.
- */
+ /* We dropped tasklist, ptracer could die and untrace */
+ ptrace_unlink(p);
+ /*
+ * If this is not a detached task, notify the parent.
+ * If it's still not detached after that, don't release
+ * it now.
+ */
+ if (p->exit_signal != -1) {
+ do_notify_parent(p, p->exit_signal);
if (p->exit_signal != -1) {
- do_notify_parent(p, p->exit_signal);
- if (p->exit_signal != -1)
- p = NULL;
+ p->exit_state = EXIT_ZOMBIE;
+ p = NULL;
}
}
write_unlock_irq(&tasklist_lock);
}
if (p != NULL)
release_task(p);
- BUG_ON(!retval);
+
return retval;
}
* the lock and this task is uninteresting. If we return nonzero, we have
* released the lock and the system call should return.
*/
-static int wait_task_stopped(struct task_struct *p, int delayed_group_leader,
+static int wait_task_stopped(struct task_struct *p,
int noreap, struct siginfo __user *infop,
int __user *stat_addr, struct rusage __user *ru)
{
- int retval, exit_code;
+ int retval, exit_code, why;
+ uid_t uid = 0; /* unneeded, required by compiler */
+ pid_t pid;
- if (!p->exit_code)
- return 0;
- if (delayed_group_leader && !(p->ptrace & PT_PTRACED) &&
- p->signal && p->signal->group_stop_count > 0)
+ exit_code = 0;
+ spin_lock_irq(&p->sighand->siglock);
+
+ if (unlikely(!task_is_stopped_or_traced(p)))
+ goto unlock_sig;
+
+ if (!(p->ptrace & PT_PTRACED) && p->signal->group_stop_count > 0)
/*
* A group stop is in progress and this is the group leader.
* We won't report until all threads have stopped.
*/
+ goto unlock_sig;
+
+ exit_code = p->exit_code;
+ if (!exit_code)
+ goto unlock_sig;
+
+ if (!noreap)
+ p->exit_code = 0;
+
+ uid = p->uid;
+unlock_sig:
+ spin_unlock_irq(&p->sighand->siglock);
+ if (!exit_code)
return 0;
/*
* possibly take page faults for user memory.
*/
get_task_struct(p);
+ pid = task_pid_vnr(p);
+ why = (p->ptrace & PT_PTRACED) ? CLD_TRAPPED : CLD_STOPPED;
read_unlock(&tasklist_lock);
- if (unlikely(noreap)) {
- pid_t pid = p->pid;
- uid_t uid = p->uid;
- int why = (p->ptrace & PT_PTRACED) ? CLD_TRAPPED : CLD_STOPPED;
-
- exit_code = p->exit_code;
- if (unlikely(!exit_code) ||
- unlikely(p->state & TASK_TRACED))
- goto bail_ref;
+ if (unlikely(noreap))
return wait_noreap_copyout(p, pid, uid,
- why, (exit_code << 8) | 0x7f,
+ why, exit_code,
infop, ru);
- }
-
- write_lock_irq(&tasklist_lock);
-
- /*
- * This uses xchg to be atomic with the thread resuming and setting
- * it. It must also be done with the write lock held to prevent a
- * race with the EXIT_ZOMBIE case.
- */
- exit_code = xchg(&p->exit_code, 0);
- if (unlikely(p->exit_state)) {
- /*
- * The task resumed and then died. Let the next iteration
- * catch it in EXIT_ZOMBIE. Note that exit_code might
- * already be zero here if it resumed and did _exit(0).
- * The task itself is dead and won't touch exit_code again;
- * other processors in this function are locked out.
- */
- p->exit_code = exit_code;
- exit_code = 0;
- }
- if (unlikely(exit_code == 0)) {
- /*
- * Another thread in this function got to it first, or it
- * resumed, or it resumed and then died.
- */
- write_unlock_irq(&tasklist_lock);
-bail_ref:
- put_task_struct(p);
- /*
- * We are returning to the wait loop without having successfully
- * removed the process and having released the lock. We cannot
- * continue, since the "p" task pointer is potentially stale.
- *
- * Return -EAGAIN, and do_wait() will restart the loop from the
- * beginning. Do _not_ re-acquire the lock.
- */
- return -EAGAIN;
- }
-
- /* move to end of parent's list to avoid starvation */
- remove_parent(p);
- add_parent(p);
-
- write_unlock_irq(&tasklist_lock);
retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
if (!retval && stat_addr)
if (!retval && infop)
retval = put_user(0, &infop->si_errno);
if (!retval && infop)
- retval = put_user((short)((p->ptrace & PT_PTRACED)
- ? CLD_TRAPPED : CLD_STOPPED),
- &infop->si_code);
+ retval = put_user((short)why, &infop->si_code);
if (!retval && infop)
retval = put_user(exit_code, &infop->si_status);
if (!retval && infop)
- retval = put_user(p->pid, &infop->si_pid);
+ retval = put_user(pid, &infop->si_pid);
if (!retval && infop)
- retval = put_user(p->uid, &infop->si_uid);
+ retval = put_user(uid, &infop->si_uid);
if (!retval)
- retval = p->pid;
+ retval = pid;
put_task_struct(p);
BUG_ON(!retval);
pid_t pid;
uid_t uid;
- if (unlikely(!p->signal))
- return 0;
-
if (!(p->signal->flags & SIGNAL_STOP_CONTINUED))
return 0;
p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
spin_unlock_irq(&p->sighand->siglock);
- pid = p->pid;
+ pid = task_pid_vnr(p);
uid = p->uid;
get_task_struct(p);
read_unlock(&tasklist_lock);
if (!retval && stat_addr)
retval = put_user(0xffff, stat_addr);
if (!retval)
- retval = p->pid;
+ retval = pid;
} else {
retval = wait_noreap_copyout(p, pid, uid,
CLD_CONTINUED, SIGCONT,
return retval;
}
-
-static inline int my_ptrace_child(struct task_struct *p)
-{
- if (!(p->ptrace & PT_PTRACED))
- return 0;
- if (!(p->ptrace & PT_ATTACHED))
- return 1;
- /*
- * This child was PTRACE_ATTACH'd. We should be seeing it only if
- * we are the attacher. If we are the real parent, this is a race
- * inside ptrace_attach. It is waiting for the tasklist_lock,
- * which we have to switch the parent links, but has already set
- * the flags in p->ptrace.
- */
- return (p->parent != p->real_parent);
-}
-
-static long do_wait(pid_t pid, int options, struct siginfo __user *infop,
- int __user *stat_addr, struct rusage __user *ru)
+static long do_wait(enum pid_type type, struct pid *pid, int options,
+ struct siginfo __user *infop, int __user *stat_addr,
+ struct rusage __user *ru)
{
DECLARE_WAITQUEUE(wait, current);
struct task_struct *tsk;
int flag, retval;
- int allowed, denied;
add_wait_queue(¤t->signal->wait_chldexit,&wait);
repeat:
+ /* If there is nothing that can match our critier just get out */
+ retval = -ECHILD;
+ if ((type < PIDTYPE_MAX) && (!pid || hlist_empty(&pid->tasks[type])))
+ goto end;
+
/*
* We will set this flag if we see any child that might later
* match our criteria, even if we are not able to reap it yet.
*/
- flag = 0;
- allowed = denied = 0;
+ flag = retval = 0;
current->state = TASK_INTERRUPTIBLE;
read_lock(&tasklist_lock);
tsk = current;
do {
struct task_struct *p;
- struct list_head *_p;
- int ret;
- list_for_each(_p,&tsk->children) {
- p = list_entry(_p, struct task_struct, sibling);
-
- ret = eligible_child(pid, options, p);
+ list_for_each_entry(p, &tsk->children, sibling) {
+ int ret = eligible_child(type, pid, options, p);
if (!ret)
continue;
if (unlikely(ret < 0)) {
- denied = ret;
- continue;
- }
- allowed = 1;
-
- switch (p->state) {
- case TASK_TRACED:
- /*
- * When we hit the race with PTRACE_ATTACH,
- * we will not report this child. But the
- * race means it has not yet been moved to
- * our ptrace_children list, so we need to
- * set the flag here to avoid a spurious ECHILD
- * when the race happens with the only child.
- */
- flag = 1;
- if (!my_ptrace_child(p))
- continue;
- /*FALLTHROUGH*/
- case TASK_STOPPED:
+ retval = ret;
+ } else if (task_is_stopped_or_traced(p)) {
/*
* It's stopped now, so it might later
* continue, exit, or stop again.
*/
flag = 1;
- if (!(options & WUNTRACED) &&
- !my_ptrace_child(p))
+ if (!(p->ptrace & PT_PTRACED) &&
+ !(options & WUNTRACED))
continue;
- retval = wait_task_stopped(p, ret == 2,
- (options & WNOWAIT),
- infop,
- stat_addr, ru);
- if (retval == -EAGAIN)
- goto repeat;
- if (retval != 0) /* He released the lock. */
- goto end;
- break;
- default:
- // case EXIT_DEAD:
- if (p->exit_state == EXIT_DEAD)
+
+ retval = wait_task_stopped(p,
+ (options & WNOWAIT), infop,
+ stat_addr, ru);
+ } else if (p->exit_state == EXIT_ZOMBIE &&
+ !delay_group_leader(p)) {
+ /*
+ * We don't reap group leaders with subthreads.
+ */
+ if (!likely(options & WEXITED))
continue;
- // case EXIT_ZOMBIE:
- if (p->exit_state == EXIT_ZOMBIE) {
- /*
- * Eligible but we cannot release
- * it yet:
- */
- if (ret == 2)
- goto check_continued;
- if (!likely(options & WEXITED))
- continue;
- retval = wait_task_zombie(
- p, (options & WNOWAIT),
- infop, stat_addr, ru);
- /* He released the lock. */
- if (retval != 0)
- goto end;
- break;
- }
-check_continued:
+ retval = wait_task_zombie(p,
+ (options & WNOWAIT), infop,
+ stat_addr, ru);
+ } else if (p->exit_state != EXIT_DEAD) {
/*
* It's running now, so it might later
* exit, stop, or stop and then continue.
flag = 1;
if (!unlikely(options & WCONTINUED))
continue;
- retval = wait_task_continued(
- p, (options & WNOWAIT),
- infop, stat_addr, ru);
- if (retval != 0) /* He released the lock. */
- goto end;
- break;
+ retval = wait_task_continued(p,
+ (options & WNOWAIT), infop,
+ stat_addr, ru);
}
+ if (retval != 0) /* tasklist_lock released */
+ goto end;
}
if (!flag) {
- list_for_each(_p, &tsk->ptrace_children) {
- p = list_entry(_p, struct task_struct,
- ptrace_list);
- if (!eligible_child(pid, options, p))
+ list_for_each_entry(p, &tsk->ptrace_children,
+ ptrace_list) {
+ flag = eligible_child(type, pid, options, p);
+ if (!flag)
continue;
- flag = 1;
- break;
+ if (likely(flag > 0))
+ break;
+ retval = flag;
+ goto end;
}
}
if (options & __WNOTHREAD)
tsk = next_thread(tsk);
BUG_ON(tsk->signal != current->signal);
} while (tsk != current);
-
read_unlock(&tasklist_lock);
+
if (flag) {
- retval = 0;
if (options & WNOHANG)
goto end;
retval = -ERESTARTSYS;
goto repeat;
}
retval = -ECHILD;
- if (unlikely(denied) && !allowed)
- retval = denied;
end:
current->state = TASK_RUNNING;
remove_wait_queue(¤t->signal->wait_chldexit,&wait);
if (infop) {
if (retval > 0)
- retval = 0;
+ retval = 0;
else {
/*
* For a WNOHANG return, clear out all the fields
return retval;
}
-asmlinkage long sys_waitid(int which, pid_t pid,
+asmlinkage long sys_waitid(int which, pid_t upid,
struct siginfo __user *infop, int options,
struct rusage __user *ru)
{
+ struct pid *pid = NULL;
+ enum pid_type type;
long ret;
if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED))
switch (which) {
case P_ALL:
- pid = -1;
+ type = PIDTYPE_MAX;
break;
case P_PID:
- if (pid <= 0)
+ type = PIDTYPE_PID;
+ if (upid <= 0)
return -EINVAL;
break;
case P_PGID:
- if (pid <= 0)
+ type = PIDTYPE_PGID;
+ if (upid <= 0)
return -EINVAL;
- pid = -pid;
break;
default:
return -EINVAL;
}
- ret = do_wait(pid, options, infop, NULL, ru);
+ if (type < PIDTYPE_MAX)
+ pid = find_get_pid(upid);
+ ret = do_wait(type, pid, options, infop, NULL, ru);
+ put_pid(pid);
/* avoid REGPARM breakage on x86: */
- prevent_tail_call(ret);
+ asmlinkage_protect(5, ret, which, upid, infop, options, ru);
return ret;
}
-asmlinkage long sys_wait4(pid_t pid, int __user *stat_addr,
+asmlinkage long sys_wait4(pid_t upid, int __user *stat_addr,
int options, struct rusage __user *ru)
{
+ struct pid *pid = NULL;
+ enum pid_type type;
long ret;
if (options & ~(WNOHANG|WUNTRACED|WCONTINUED|
__WNOTHREAD|__WCLONE|__WALL))
return -EINVAL;
- ret = do_wait(pid, options | WEXITED, NULL, stat_addr, ru);
+
+ if (upid == -1)
+ type = PIDTYPE_MAX;
+ else if (upid < 0) {
+ type = PIDTYPE_PGID;
+ pid = find_get_pid(-upid);
+ } else if (upid == 0) {
+ type = PIDTYPE_PGID;
+ pid = get_pid(task_pgrp(current));
+ } else /* upid > 0 */ {
+ type = PIDTYPE_PID;
+ pid = find_get_pid(upid);
+ }
+
+ ret = do_wait(type, pid, options | WEXITED, NULL, stat_addr, ru);
+ put_pid(pid);
/* avoid REGPARM breakage on x86: */
- prevent_tail_call(ret);
+ asmlinkage_protect(4, ret, upid, stat_addr, options, ru);
return ret;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff