#include <linux/personality.h>
#include <linux/tty.h>
#include <linux/mnt_namespace.h>
+#include <linux/iocontext.h>
#include <linux/key.h>
#include <linux/security.h>
#include <linux/cpu.h>
#include <linux/acct.h>
#include <linux/tsacct_kern.h>
#include <linux/file.h>
+#include <linux/fdtable.h>
#include <linux/binfmts.h>
#include <linux/nsproxy.h>
#include <linux/pid_namespace.h>
#include <linux/resource.h>
#include <linux/blkdev.h>
#include <linux/task_io_accounting_ops.h>
+#include <linux/tracehook.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
static void exit_mm(struct task_struct * tsk);
+static inline int task_detached(struct task_struct *p)
+{
+ return p->exit_signal == -1;
+}
+
static void __unhash_process(struct task_struct *p)
{
nr_threads--;
__get_cpu_var(process_counts)--;
}
list_del_rcu(&p->thread_group);
- remove_parent(p);
+ list_del_init(&p->sibling);
}
/*
BUG_ON(!sig);
BUG_ON(!atomic_read(&sig->count));
- rcu_read_lock();
sighand = rcu_dereference(tsk->sighand);
spin_lock(&sighand->siglock);
sig->nivcsw += tsk->nivcsw;
sig->inblock += task_io_get_inblock(tsk);
sig->oublock += task_io_get_oublock(tsk);
+#ifdef CONFIG_TASK_XACCT
+ sig->rchar += tsk->rchar;
+ sig->wchar += tsk->wchar;
+ sig->syscr += tsk->syscr;
+ sig->syscw += tsk->syscw;
+#endif /* CONFIG_TASK_XACCT */
+#ifdef CONFIG_TASK_IO_ACCOUNTING
+ sig->ioac.read_bytes += tsk->ioac.read_bytes;
+ sig->ioac.write_bytes += tsk->ioac.write_bytes;
+ sig->ioac.cancelled_write_bytes +=
+ tsk->ioac.cancelled_write_bytes;
+#endif /* CONFIG_TASK_IO_ACCOUNTING */
sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
sig = NULL; /* Marker for below. */
}
__unhash_process(tsk);
+ /*
+ * Do this under ->siglock, we can race with another thread
+ * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
+ */
+ flush_sigqueue(&tsk->pending);
+
tsk->signal = NULL;
tsk->sighand = NULL;
spin_unlock(&sighand->siglock);
- rcu_read_unlock();
__cleanup_sighand(sighand);
clear_tsk_thread_flag(tsk,TIF_SIGPENDING);
- flush_sigqueue(&tsk->pending);
if (sig) {
flush_sigqueue(&sig->shared_pending);
taskstats_tgid_free(sig);
put_task_struct(container_of(rhp, struct task_struct, rcu));
}
+/*
+ * Do final ptrace-related cleanup of a zombie being reaped.
+ *
+ * Called with write_lock(&tasklist_lock) held.
+ */
+static void ptrace_release_task(struct task_struct *p)
+{
+ BUG_ON(!list_empty(&p->ptraced));
+ ptrace_unlink(p);
+ BUG_ON(!list_empty(&p->ptrace_entry));
+}
+
void release_task(struct task_struct * p)
{
struct task_struct *leader;
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));
+ ptrace_release_task(p);
__exit_signal(p);
/*
zap_leader = 0;
leader = p->group_leader;
if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) {
- BUG_ON(leader->exit_signal == -1);
+ BUG_ON(task_detached(leader));
do_notify_parent(leader, leader->exit_signal);
/*
* If we were the last child thread and the leader has
* do_notify_parent() will have marked it self-reaping in
* that case.
*/
- zap_leader = (leader->exit_signal == -1);
+ zap_leader = task_detached(leader);
}
write_unlock_irq(&tasklist_lock);
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_global_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)
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
*
ptrace_unlink(current);
/* Reparent to init */
- remove_parent(current);
current->real_parent = current->parent = kthreadd_task;
- add_parent(current);
+ list_move_tail(¤t->sibling, ¤t->real_parent->children);
/* Set the exit signal to SIGCHLD so we signal init on exit */
current->exit_signal = SIGCHLD;
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 (task_session_nr(curr) != session) {
- detach_pid(curr, PIDTYPE_SID);
- set_task_session(curr, session);
- attach_pid(curr, PIDTYPE_SID, find_pid(session));
+ if (task_session(curr) != pid) {
+ change_pid(curr, PIDTYPE_SID, pid);
+ set_task_session(curr, nr);
}
- if (task_pgrp_nr(curr) != pgrp) {
- detach_pid(curr, PIDTYPE_PGID);
- set_task_pgrp(curr, pgrp);
- attach_pid(curr, PIDTYPE_PGID, find_pid(pgrp));
+ if (task_pgrp(curr) != pid) {
+ change_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);
}
* We don't want to have TIF_FREEZE set if the system-wide hibernation
* or suspend transition begins right now.
*/
- current->flags |= PF_NOFREEZE;
+ current->flags |= (PF_NOFREEZE | PF_KTHREAD);
- 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);
- if (current->nsproxy != init_task.nsproxy) {
- get_nsproxy(init_task.nsproxy);
- switch_task_namespaces(current, init_task.nsproxy);
- }
-
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 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 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 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
static void exit_mm(struct task_struct * tsk)
{
struct mm_struct *mm = tsk->mm;
+ struct core_state *core_state;
mm_release(tsk, mm);
if (!mm)
return;
/*
* Serialize with any possible pending coredump.
- * We must hold mmap_sem around checking core_waiters
+ * We must hold mmap_sem around checking core_state
* and clearing tsk->mm. The core-inducing thread
- * will increment core_waiters for each thread in the
+ * will increment ->nr_threads for each thread in the
* group with ->mm != NULL.
*/
down_read(&mm->mmap_sem);
- if (mm->core_waiters) {
+ core_state = mm->core_state;
+ if (core_state) {
+ struct core_thread self;
up_read(&mm->mmap_sem);
- down_write(&mm->mmap_sem);
- if (!--mm->core_waiters)
- complete(mm->core_startup_done);
- up_write(&mm->mmap_sem);
- wait_for_completion(&mm->core_done);
+ self.task = tsk;
+ self.next = xchg(&core_state->dumper.next, &self);
+ /*
+ * Implies mb(), the result of xchg() must be visible
+ * to core_state->dumper.
+ */
+ if (atomic_dec_and_test(&core_state->nr_threads))
+ complete(&core_state->startup);
+
+ for (;;) {
+ set_task_state(tsk, TASK_UNINTERRUPTIBLE);
+ if (!self.task) /* see coredump_finish() */
+ break;
+ schedule();
+ }
+ __set_task_state(tsk, TASK_RUNNING);
down_read(&mm->mmap_sem);
}
atomic_inc(&mm->mm_count);
/* 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 void
-reparent_thread(struct task_struct *p, struct task_struct *father, int traced)
+/*
+ * Return nonzero if @parent's children should reap themselves.
+ *
+ * Called with write_lock_irq(&tasklist_lock) held.
+ */
+static int ignoring_children(struct task_struct *parent)
{
- if (p->pdeath_signal)
- /* We already hold the tasklist_lock here. */
- group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p);
+ int ret;
+ struct sighand_struct *psig = parent->sighand;
+ unsigned long flags;
+ spin_lock_irqsave(&psig->siglock, flags);
+ ret = (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN ||
+ (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT));
+ spin_unlock_irqrestore(&psig->siglock, flags);
+ return ret;
+}
- /* Move the child from its dying parent to the new one. */
- if (unlikely(traced)) {
- /* Preserve ptrace links if someone else is tracing this child. */
- list_del_init(&p->ptrace_list);
- if (p->parent != p->real_parent)
- list_add(&p->ptrace_list, &p->real_parent->ptrace_children);
- } else {
- /* If this child is being traced, then we're the one tracing it
- * anyway, so let go of it.
+/*
+ * Detach all tasks we were using ptrace on.
+ * Any that need to be release_task'd are put on the @dead list.
+ *
+ * Called with write_lock(&tasklist_lock) held.
+ */
+static void ptrace_exit(struct task_struct *parent, struct list_head *dead)
+{
+ struct task_struct *p, *n;
+ int ign = -1;
+
+ list_for_each_entry_safe(p, n, &parent->ptraced, ptrace_entry) {
+ __ptrace_unlink(p);
+
+ if (p->exit_state != EXIT_ZOMBIE)
+ continue;
+
+ /*
+ * If it's a zombie, our attachedness prevented normal
+ * parent notification or self-reaping. Do notification
+ * now if it would have happened earlier. If it should
+ * reap itself, add it to the @dead list. We can't call
+ * release_task() here because we already hold tasklist_lock.
+ *
+ * If it's our own child, there is no notification to do.
+ * But if our normal children self-reap, then this child
+ * was prevented by ptrace and we must reap it now.
*/
- p->ptrace = 0;
- remove_parent(p);
- p->parent = p->real_parent;
- add_parent(p);
+ if (!task_detached(p) && thread_group_empty(p)) {
+ if (!same_thread_group(p->real_parent, parent))
+ do_notify_parent(p, p->exit_signal);
+ else {
+ if (ign < 0)
+ ign = ignoring_children(parent);
+ if (ign)
+ p->exit_signal = -1;
+ }
+ }
- if (task_is_traced(p)) {
+ if (task_detached(p)) {
/*
- * If it was at a trace stop, turn it into
- * a normal stop since it's no longer being
- * traced.
+ * Mark it as in the process of being reaped.
*/
- ptrace_untrace(p);
+ p->exit_state = EXIT_DEAD;
+ list_add(&p->ptrace_entry, dead);
}
}
+}
+
+/*
+ * Finish up exit-time ptrace cleanup.
+ *
+ * Called without locks.
+ */
+static void ptrace_exit_finish(struct task_struct *parent,
+ struct list_head *dead)
+{
+ struct task_struct *p, *n;
+
+ BUG_ON(!list_empty(&parent->ptraced));
+
+ list_for_each_entry_safe(p, n, dead, ptrace_entry) {
+ list_del_init(&p->ptrace_entry);
+ release_task(p);
+ }
+}
+
+static void reparent_thread(struct task_struct *p, struct task_struct *father)
+{
+ if (p->pdeath_signal)
+ /* We already hold the tasklist_lock here. */
+ group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p);
+
+ list_move_tail(&p->sibling, &p->real_parent->children);
/* If this is a threaded reparent there is no need to
* notify anyone anything has happened.
*/
- if (p->real_parent->group_leader == father->group_leader)
+ if (same_thread_group(p->real_parent, father))
return;
/* We don't want people slaying init. */
- if (p->exit_signal != -1)
+ if (!task_detached(p))
p->exit_signal = SIGCHLD;
/* If we'd notified the old parent about this child's death,
* also notify the new parent.
*/
- if (!traced && p->exit_state == EXIT_ZOMBIE &&
- p->exit_signal != -1 && thread_group_empty(p))
+ if (!ptrace_reparented(p) &&
+ p->exit_state == EXIT_ZOMBIE &&
+ !task_detached(p) && 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);
}
/*
static void forget_original_parent(struct task_struct *father)
{
struct task_struct *p, *n, *reaper = father;
- struct list_head ptrace_dead;
-
- INIT_LIST_HEAD(&ptrace_dead);
+ LIST_HEAD(ptrace_dead);
write_lock_irq(&tasklist_lock);
+ /*
+ * First clean up ptrace if we were using it.
+ */
+ ptrace_exit(father, &ptrace_dead);
+
do {
reaper = next_thread(reaper);
if (reaper == father) {
}
} while (reaper->flags & PF_EXITING);
- /*
- * There are only two places where our children can be:
- *
- * - in our child list
- * - in our ptraced child list
- *
- * Search them and reparent children.
- */
list_for_each_entry_safe(p, n, &father->children, sibling) {
- int ptrace;
-
- ptrace = p->ptrace;
-
- /* if father isn't the real parent, then ptrace must be enabled */
- BUG_ON(father != p->real_parent && !ptrace);
-
- if (father == p->real_parent) {
- /* reparent with a reaper, real father it's us */
- p->real_parent = reaper;
- reparent_thread(p, father, 0);
- } else {
- /* reparent ptraced task to its real parent */
- __ptrace_unlink (p);
- if (p->exit_state == EXIT_ZOMBIE && p->exit_signal != -1 &&
- thread_group_empty(p))
- do_notify_parent(p, p->exit_signal);
- }
-
- /*
- * if the ptraced child is a zombie with exit_signal == -1
- * we must collect it before we exit, or it will remain
- * zombie forever since we prevented it from self-reap itself
- * 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, &ptrace_dead);
- }
-
- list_for_each_entry_safe(p, n, &father->ptrace_children, ptrace_list) {
p->real_parent = reaper;
- reparent_thread(p, father, 1);
+ if (p->parent == father) {
+ BUG_ON(p->ptrace);
+ p->parent = p->real_parent;
+ }
+ reparent_thread(p, father);
}
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);
- }
+ ptrace_exit_finish(father, &ptrace_dead);
}
/*
* 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 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.
- */
- 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);
- }
/*
* This does two things:
exit_task_namespaces(tsk);
write_lock_irq(&tasklist_lock);
- /*
- * 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);
- }
+ if (group_dead)
+ kill_orphaned_pgrp(tsk->group_leader, NULL);
/* Let father know we died
*
* 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)
- && !capable(CAP_KILL))
+ if (tsk->exit_signal != SIGCHLD && !task_detached(tsk) &&
+ (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;
-
/* If something other than our normal parent is ptracing us, then
* send it a SIGCHLD instead of honoring exit_signal. exit_signal
* only has special meaning to our real parent.
*/
- if (tsk->exit_signal != -1 && thread_group_empty(tsk)) {
- int signal = tsk->parent == tsk->real_parent ? tsk->exit_signal : SIGCHLD;
+ if (!task_detached(tsk) && thread_group_empty(tsk)) {
+ int signal = ptrace_reparented(tsk) ?
+ SIGCHLD : tsk->exit_signal;
do_notify_parent(tsk, signal);
} else if (tsk->ptrace) {
do_notify_parent(tsk, SIGCHLD);
}
state = EXIT_ZOMBIE;
- if (tsk->exit_signal == -1 && likely(!tsk->ptrace))
+ if (task_detached(tsk) && likely(!tsk->ptrace))
state = EXIT_DEAD;
tsk->exit_state = state;
+ /* mt-exec, de_thread() is waiting for us */
if (thread_group_leader(tsk) &&
tsk->signal->notify_count < 0 &&
tsk->signal->group_exit_task)
zap_pid_ns_processes(tsk->nsproxy->pid_ns);
}
-fastcall NORET_TYPE void do_exit(long code)
+NORET_TYPE void do_exit(long code)
{
struct task_struct *tsk = current;
int group_dead;
if (unlikely(!tsk->pid))
panic("Attempted to kill the idle task!");
- if (unlikely(current->ptrace & PT_TRACE_EXIT)) {
- current->ptrace_message = code;
- ptrace_notify((PTRACE_EVENT_EXIT << 8) | SIGTRAP);
- }
+ tracehook_report_exit(&code);
/*
* We're taking recursive faults here in do_exit. Safest is to just
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.
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();
cgroup_exit(tsk, 1);
module_put(tsk->binfmt->module);
proc_exit_connector(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
NORET_TYPE void
do_group_exit(int exit_code)
{
+ struct signal_struct *sig = current->signal;
+
BUG_ON(exit_code & 0x80); /* core dumps don't get here */
- if (current->signal->flags & SIGNAL_GROUP_EXIT)
- exit_code = current->signal->group_exit_code;
+ if (signal_group_exit(sig))
+ exit_code = sig->group_exit_code;
else if (!thread_group_empty(current)) {
- struct signal_struct *const sig = current->signal;
struct sighand_struct *const sighand = current->sighand;
spin_lock_irq(&sighand->siglock);
if (signal_group_exit(sig))
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;
- struct pid_namespace *ns;
- ns = current->nsproxy->pid_ns;
- if (pid > 0) {
- if (task_pid_nr_ns(p, ns) != pid)
- return 0;
- } else if (!pid) {
- if (task_pgrp_nr_ns(p, ns) != task_pgrp_vnr(current))
- return 0;
- } else if (pid != -1) {
- if (task_pgrp_nr_ns(p, ns) != -pid)
+ if (type < PIDTYPE_MAX) {
+ if (task_pid_type(p, type) != pid)
return 0;
}
- /*
- * Do not consider detached threads that are
- * not ptraced:
- */
- if (p->exit_signal == -1 && !p->ptrace)
- return 0;
-
/* Wait for all children (clone and not) if __WALL is set;
* otherwise, wait for clone children *only* if __WCLONE is
* set; otherwise, wait for non-clone children *only*. (Note:
return 0;
err = security_task_wait(p);
- if (likely(!err))
- return 1;
+ if (err)
+ return err;
- if (pid <= 0)
- return 0;
- /* This child was explicitly requested, abort */
- read_unlock(&tasklist_lock);
- return err;
+ return 1;
}
static int wait_noreap_copyout(struct task_struct *p, pid_t pid, uid_t uid,
* 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_zombie(struct task_struct *p, int noreap,
+static int wait_task_zombie(struct task_struct *p, int options,
struct siginfo __user *infop,
int __user *stat_addr, struct rusage __user *ru)
{
unsigned long state;
int retval, status, traced;
- pid_t pid = task_pid_nr_ns(p, current->nsproxy->pid_ns);
+ pid_t pid = task_pid_vnr(p);
+
+ if (!likely(options & WEXITED))
+ return 0;
- if (unlikely(noreap)) {
+ if (unlikely(options & WNOWAIT)) {
uid_t uid = p->uid;
int exit_code = p->exit_code;
int why, status;
return 0;
}
- /* traced means p->ptrace, but not vice versa */
- traced = (p->real_parent != p->parent);
+ traced = ptrace_reparented(p);
if (likely(!traced)) {
struct signal_struct *psig;
psig->coublock +=
task_io_get_oublock(p) +
sig->oublock + sig->coublock;
+#ifdef CONFIG_TASK_XACCT
+ psig->rchar += p->rchar + sig->rchar;
+ psig->wchar += p->wchar + sig->wchar;
+ psig->syscr += p->syscr + sig->syscr;
+ psig->syscw += p->syscw + sig->syscw;
+#endif /* CONFIG_TASK_XACCT */
+#ifdef CONFIG_TASK_IO_ACCOUNTING
+ psig->ioac.read_bytes +=
+ p->ioac.read_bytes + sig->ioac.read_bytes;
+ psig->ioac.write_bytes +=
+ p->ioac.write_bytes + sig->ioac.write_bytes;
+ psig->ioac.cancelled_write_bytes +=
+ p->ioac.cancelled_write_bytes +
+ sig->ioac.cancelled_write_bytes;
+#endif /* CONFIG_TASK_IO_ACCOUNTING */
spin_unlock_irq(&p->parent->sighand->siglock);
}
* If it's still not detached after that, don't release
* it now.
*/
- if (p->exit_signal != -1) {
+ if (!task_detached(p)) {
do_notify_parent(p, p->exit_signal);
- if (p->exit_signal != -1) {
+ if (!task_detached(p)) {
p->exit_state = EXIT_ZOMBIE;
p = NULL;
}
* 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 noreap, struct siginfo __user *infop,
+static int wait_task_stopped(int ptrace, struct task_struct *p,
+ int options, struct siginfo __user *infop,
int __user *stat_addr, struct rusage __user *ru)
{
int retval, exit_code, why;
uid_t uid = 0; /* unneeded, required by compiler */
pid_t pid;
+ if (!(options & WUNTRACED))
+ return 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)
+ if (!ptrace && 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.
if (!exit_code)
goto unlock_sig;
- if (!noreap)
+ if (!unlikely(options & WNOWAIT))
p->exit_code = 0;
uid = p->uid;
* possibly take page faults for user memory.
*/
get_task_struct(p);
- pid = task_pid_nr_ns(p, current->nsproxy->pid_ns);
- why = (p->ptrace & PT_PTRACED) ? CLD_TRAPPED : CLD_STOPPED;
+ pid = task_pid_vnr(p);
+ why = ptrace ? CLD_TRAPPED : CLD_STOPPED;
read_unlock(&tasklist_lock);
- if (unlikely(noreap))
+ if (unlikely(options & WNOWAIT))
return wait_noreap_copyout(p, pid, uid,
why, exit_code,
infop, ru);
if (!retval && infop)
retval = put_user(0, &infop->si_errno);
if (!retval && infop)
- retval = put_user(why, &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)
* 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_continued(struct task_struct *p, int noreap,
+static int wait_task_continued(struct task_struct *p, int options,
struct siginfo __user *infop,
int __user *stat_addr, struct rusage __user *ru)
{
pid_t pid;
uid_t uid;
+ if (!unlikely(options & WCONTINUED))
+ return 0;
+
if (!(p->signal->flags & SIGNAL_STOP_CONTINUED))
return 0;
spin_unlock_irq(&p->sighand->siglock);
return 0;
}
- if (!noreap)
+ if (!unlikely(options & WNOWAIT))
p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
spin_unlock_irq(&p->sighand->siglock);
- pid = task_pid_nr_ns(p, current->nsproxy->pid_ns);
+ pid = task_pid_vnr(p);
uid = p->uid;
get_task_struct(p);
read_unlock(&tasklist_lock);
return retval;
}
-static long do_wait(pid_t pid, int options, struct siginfo __user *infop,
- int __user *stat_addr, struct rusage __user *ru)
+/*
+ * Consider @p for a wait by @parent.
+ *
+ * -ECHILD should be in *@notask_error before the first call.
+ * Returns nonzero for a final return, when we have unlocked tasklist_lock.
+ * Returns zero if the search for a child should continue;
+ * then *@notask_error is 0 if @p is an eligible child,
+ * or another error from security_task_wait(), or still -ECHILD.
+ */
+static int wait_consider_task(struct task_struct *parent, int ptrace,
+ struct task_struct *p, int *notask_error,
+ enum pid_type type, struct pid *pid, int options,
+ struct siginfo __user *infop,
+ int __user *stat_addr, struct rusage __user *ru)
+{
+ int ret = eligible_child(type, pid, options, p);
+ if (!ret)
+ return ret;
+
+ if (unlikely(ret < 0)) {
+ /*
+ * If we have not yet seen any eligible child,
+ * then let this error code replace -ECHILD.
+ * A permission error will give the user a clue
+ * to look for security policy problems, rather
+ * than for mysterious wait bugs.
+ */
+ if (*notask_error)
+ *notask_error = ret;
+ }
+
+ if (likely(!ptrace) && unlikely(p->ptrace)) {
+ /*
+ * This child is hidden by ptrace.
+ * We aren't allowed to see it now, but eventually we will.
+ */
+ *notask_error = 0;
+ return 0;
+ }
+
+ if (p->exit_state == EXIT_DEAD)
+ return 0;
+
+ /*
+ * We don't reap group leaders with subthreads.
+ */
+ if (p->exit_state == EXIT_ZOMBIE && !delay_group_leader(p))
+ return wait_task_zombie(p, options, infop, stat_addr, ru);
+
+ /*
+ * It's stopped or running now, so it might
+ * later continue, exit, or stop again.
+ */
+ *notask_error = 0;
+
+ if (task_is_stopped_or_traced(p))
+ return wait_task_stopped(ptrace, p, options,
+ infop, stat_addr, ru);
+
+ return wait_task_continued(p, options, infop, stat_addr, ru);
+}
+
+/*
+ * Do the work of do_wait() for one thread in the group, @tsk.
+ *
+ * -ECHILD should be in *@notask_error before the first call.
+ * Returns nonzero for a final return, when we have unlocked tasklist_lock.
+ * Returns zero if the search for a child should continue; then
+ * *@notask_error is 0 if there were any eligible children,
+ * or another error from security_task_wait(), or still -ECHILD.
+ */
+static int do_wait_thread(struct task_struct *tsk, int *notask_error,
+ enum pid_type type, struct pid *pid, int options,
+ struct siginfo __user *infop, int __user *stat_addr,
+ struct rusage __user *ru)
+{
+ struct task_struct *p;
+
+ list_for_each_entry(p, &tsk->children, sibling) {
+ /*
+ * Do not consider detached threads.
+ */
+ if (!task_detached(p)) {
+ int ret = wait_consider_task(tsk, 0, p, notask_error,
+ type, pid, options,
+ infop, stat_addr, ru);
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static int ptrace_do_wait(struct task_struct *tsk, int *notask_error,
+ enum pid_type type, struct pid *pid, int options,
+ struct siginfo __user *infop, int __user *stat_addr,
+ struct rusage __user *ru)
+{
+ struct task_struct *p;
+
+ /*
+ * Traditionally we see ptrace'd stopped tasks regardless of options.
+ */
+ options |= WUNTRACED;
+
+ list_for_each_entry(p, &tsk->ptraced, ptrace_entry) {
+ int ret = wait_consider_task(tsk, 1, p, notask_error,
+ type, pid, options,
+ infop, stat_addr, ru);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+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 retval;
add_wait_queue(¤t->signal->wait_chldexit,&wait);
repeat:
/*
- * We will set this flag if we see any child that might later
+ * If there is nothing that can match our critiera just get out.
+ * We will clear @retval to zero if we see any child that might later
* match our criteria, even if we are not able to reap it yet.
*/
- flag = retval = 0;
+ retval = -ECHILD;
+ if ((type < PIDTYPE_MAX) && (!pid || hlist_empty(&pid->tasks[type])))
+ goto end;
+
current->state = TASK_INTERRUPTIBLE;
read_lock(&tasklist_lock);
tsk = current;
do {
- struct task_struct *p;
-
- list_for_each_entry(p, &tsk->children, sibling) {
- int ret = eligible_child(pid, options, p);
- if (!ret)
- continue;
-
- if (unlikely(ret < 0)) {
- 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 (!(p->ptrace & PT_PTRACED) &&
- !(options & WUNTRACED))
- continue;
-
- 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;
- 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) /* tasklist_lock released */
- goto end;
- }
- if (!flag) {
- list_for_each_entry(p, &tsk->ptrace_children,
- ptrace_list) {
- flag = eligible_child(pid, options, p);
- if (!flag)
- continue;
- if (likely(flag > 0))
- break;
- retval = flag;
- goto end;
- }
+ int tsk_result = do_wait_thread(tsk, &retval,
+ type, pid, options,
+ infop, stat_addr, ru);
+ if (!tsk_result)
+ tsk_result = ptrace_do_wait(tsk, &retval,
+ type, pid, options,
+ infop, stat_addr, ru);
+ if (tsk_result) {
+ /*
+ * tasklist_lock is unlocked and we have a final result.
+ */
+ retval = tsk_result;
+ goto end;
}
+
if (options & __WNOTHREAD)
break;
tsk = next_thread(tsk);
} while (tsk != current);
read_unlock(&tasklist_lock);
- if (flag) {
- if (options & WNOHANG)
- goto end;
+ if (!retval && !(options & WNOHANG)) {
retval = -ERESTARTSYS;
- if (signal_pending(current))
- goto end;
- schedule();
- goto repeat;
+ if (!signal_pending(current)) {
+ schedule();
+ goto repeat;
+ }
}
- retval = -ECHILD;
+
end:
current->state = TASK_RUNNING;
remove_wait_queue(¤t->signal->wait_chldexit,&wait);
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