#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>
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--;
__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);
__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);
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
*
pid_t nr = pid_nr(pid);
if (task_session(curr) != pid) {
- detach_pid(curr, PIDTYPE_SID);
- attach_pid(curr, PIDTYPE_SID, pid);
+ change_pid(curr, PIDTYPE_SID, pid);
set_task_session(curr, nr);
}
if (task_pgrp(curr) != pid) {
- detach_pid(curr, PIDTYPE_PGID);
- attach_pid(curr, PIDTYPE_PGID, pid);
+ change_pid(curr, PIDTYPE_PGID, pid);
set_task_pgrp(curr, nr);
}
}
}
}
-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
/* We don't want this task to be frozen prematurely */
clear_freeze_flag(tsk);
task_unlock(tsk);
+ mm_update_next_owner(mm);
mmput(mm);
}
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)
+ if (ptrace_reparented(p))
list_add(&p->ptrace_list, &p->real_parent->ptrace_children);
} else {
/* If this child is being traced, then we're the one tracing it
/* 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))
+ !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);
}
/*
} else {
/* reparent ptraced task to its real parent */
__ptrace_unlink (p);
- if (p->exit_state == EXIT_ZOMBIE && p->exit_signal != -1 &&
+ if (p->exit_state == EXIT_ZOMBIE && !task_detached(p) &&
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 the ptraced child is a detached zombie 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))
+ if (unlikely(ptrace && p->exit_state == EXIT_ZOMBIE && task_detached(p)))
list_add(&p->ptrace_list, &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;
/*
* 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)
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 not consider detached threads that are
* not ptraced:
*/
- if (p->exit_signal == -1 && !p->ptrace)
+ if (task_detached(p) && !p->ptrace)
return 0;
/* Wait for all children (clone and not) if __WALL is set;
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;
* 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;
}
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)
put_pid(pid);
/* avoid REGPARM breakage on x86: */
- prevent_tail_call(ret);
+ asmlinkage_protect(5, ret, which, upid, infop, options, ru);
return ret;
}
put_pid(pid);
/* avoid REGPARM breakage on x86: */
- prevent_tail_call(ret);
+ asmlinkage_protect(4, ret, upid, stat_addr, options, ru);
return ret;
}