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Merge branch 'linus' into stackprotector

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Conflicts:
	arch/x86/kernel/Makefile
	include/asm-x86/pda.h
This commit is contained in:
Ingo Molnar
2008-10-15 13:46:29 +02:00
parent 4f962d4d65 278429cff8
commit b2aaf8f74c
15391 changed files with 1154074 additions and 777808 deletions
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628
kernel/exit.c
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@@ -13,6 +13,7 @@
#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>
@@ -45,6 +46,7 @@
#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>
@@ -70,7 +72,7 @@ static void __unhash_process(struct task_struct *p)
__get_cpu_var(process_counts)--;
}
list_del_rcu(&p->thread_group);
remove_parent(p);
list_del_init(&p->sibling);
}
/*
@@ -84,7 +86,6 @@ static void __exit_signal(struct task_struct *tsk)
BUG_ON(!sig);
BUG_ON(!atomic_read(&sig->count));
rcu_read_lock();
sighand = rcu_dereference(tsk->sighand);
spin_lock(&sighand->siglock);
@@ -111,15 +112,16 @@ static void __exit_signal(struct task_struct *tsk)
* We won't ever get here for the group leader, since it
* will have been the last reference on the signal_struct.
*/
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->utime = cputime_add(sig->utime, task_utime(tsk));
sig->stime = cputime_add(sig->stime, task_stime(tsk));
sig->gtime = cputime_add(sig->gtime, task_gtime(tsk));
sig->min_flt += tsk->min_flt;
sig->maj_flt += tsk->maj_flt;
sig->nvcsw += tsk->nvcsw;
sig->nivcsw += tsk->nivcsw;
sig->inblock += task_io_get_inblock(tsk);
sig->oublock += task_io_get_oublock(tsk);
task_io_accounting_add(&sig->ioac, &tsk->ioac);
sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
sig = NULL; /* Marker for below. */
}
@@ -135,7 +137,6 @@ static void __exit_signal(struct task_struct *tsk)
tsk->signal = NULL;
tsk->sighand = NULL;
spin_unlock(&sighand->siglock);
rcu_read_unlock();
__cleanup_sighand(sighand);
clear_tsk_thread_flag(tsk,TIF_SIGPENDING);
@@ -151,16 +152,17 @@ static void delayed_put_task_struct(struct rcu_head *rhp)
put_task_struct(container_of(rhp, struct task_struct, rcu));
}
void release_task(struct task_struct * p)
{
struct task_struct *leader;
int zap_leader;
repeat:
tracehook_prepare_release_task(p);
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));
tracehook_finish_release_task(p);
__exit_signal(p);
/*
@@ -182,6 +184,13 @@ repeat:
* that case.
*/
zap_leader = task_detached(leader);
/*
* This maintains the invariant that release_task()
* only runs on a task in EXIT_DEAD, just for sanity.
*/
if (zap_leader)
leader->exit_state = EXIT_DEAD;
}
write_unlock_irq(&tasklist_lock);
@@ -314,9 +323,8 @@ static void reparent_to_kthreadd(void)
ptrace_unlink(current);
/* Reparent to init */
remove_parent(current);
current->real_parent = current->parent = kthreadd_task;
add_parent(current);
list_move_tail(&current->sibling, &current->real_parent->children);
/* Set the exit signal to SIGCHLD so we signal init on exit */
current->exit_signal = SIGCHLD;
@@ -421,7 +429,7 @@ void daemonize(const char *name, ...)
* 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);
if (current->nsproxy != &init_nsproxy) {
get_nsproxy(&init_nsproxy);
@@ -546,8 +554,6 @@ void put_fs_struct(struct fs_struct *fs)
if (atomic_dec_and_test(&fs->count)) {
path_put(&fs->root);
path_put(&fs->pwd);
if (fs->altroot.dentry)
path_put(&fs->altroot);
kmem_cache_free(fs_cachep, fs);
}
}
@@ -577,8 +583,6 @@ mm_need_new_owner(struct mm_struct *mm, struct task_struct *p)
* 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)
@@ -621,6 +625,16 @@ retry:
} while_each_thread(g, c);
read_unlock(&tasklist_lock);
/*
* We found no owner yet mm_users > 1: this implies that we are
* most likely racing with swapoff (try_to_unuse()) or /proc or
* ptrace or page migration (get_task_mm()). Mark owner as NULL,
* so that subsystems can understand the callback and take action.
*/
down_write(&mm->mmap_sem);
cgroup_mm_owner_callbacks(mm->owner, NULL);
mm->owner = NULL;
up_write(&mm->mmap_sem);
return;
assign_new_owner:
@@ -655,26 +669,40 @@ assign_new_owner:
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);
@@ -691,37 +719,97 @@ static void exit_mm(struct task_struct * tsk)
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)
{
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;
}
/*
* 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.
*/
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_detached(p)) {
/*
* Mark it as in the process of being reaped.
*/
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);
/* 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 (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
* anyway, so let go of it.
*/
p->ptrace = 0;
remove_parent(p);
p->parent = p->real_parent;
add_parent(p);
if (task_is_traced(p)) {
/*
* If it was at a trace stop, turn it into
* a normal stop since it's no longer being
* traced.
*/
ptrace_untrace(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.
@@ -736,7 +824,8 @@ reparent_thread(struct task_struct *p, struct task_struct *father, int traced)
/* If we'd notified the old parent about this child's death,
* also notify the new parent.
*/
if (!traced && p->exit_state == EXIT_ZOMBIE &&
if (!ptrace_reparented(p) &&
p->exit_state == EXIT_ZOMBIE &&
!task_detached(p) && thread_group_empty(p))
do_notify_parent(p, p->exit_signal);
@@ -750,75 +839,63 @@ reparent_thread(struct task_struct *p, struct task_struct *father, int traced)
* the child reaper process (ie "init") in our pid
* space.
*/
static void forget_original_parent(struct task_struct *father)
static struct task_struct *find_new_reaper(struct task_struct *father)
{
struct task_struct *p, *n, *reaper = father;
struct list_head ptrace_dead;
struct pid_namespace *pid_ns = task_active_pid_ns(father);
struct task_struct *thread;
INIT_LIST_HEAD(&ptrace_dead);
write_lock_irq(&tasklist_lock);
do {
reaper = next_thread(reaper);
if (reaper == father) {
reaper = task_child_reaper(father);
break;
}
} 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 && !task_detached(p) &&
thread_group_empty(p))
do_notify_parent(p, p->exit_signal);
}
/*
* 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 && task_detached(p)))
list_add(&p->ptrace_list, &ptrace_dead);
thread = father;
while_each_thread(father, thread) {
if (thread->flags & PF_EXITING)
continue;
if (unlikely(pid_ns->child_reaper == father))
pid_ns->child_reaper = thread;
return thread;
}
list_for_each_entry_safe(p, n, &father->ptrace_children, ptrace_list) {
if (unlikely(pid_ns->child_reaper == father)) {
write_unlock_irq(&tasklist_lock);
if (unlikely(pid_ns == &init_pid_ns))
panic("Attempted to kill init!");
zap_pid_ns_processes(pid_ns);
write_lock_irq(&tasklist_lock);
/*
* We can not clear ->child_reaper or leave it alone.
* There may by stealth EXIT_DEAD tasks on ->children,
* forget_original_parent() must move them somewhere.
*/
pid_ns->child_reaper = init_pid_ns.child_reaper;
}
return pid_ns->child_reaper;
}
static void forget_original_parent(struct task_struct *father)
{
struct task_struct *p, *n, *reaper;
LIST_HEAD(ptrace_dead);
write_lock_irq(&tasklist_lock);
reaper = find_new_reaper(father);
/*
* First clean up ptrace if we were using it.
*/
ptrace_exit(father, &ptrace_dead);
list_for_each_entry_safe(p, n, &father->children, sibling) {
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);
}
/*
@@ -827,7 +904,8 @@ static void forget_original_parent(struct task_struct *father)
*/
static void exit_notify(struct task_struct *tsk, int group_dead)
{
int state;
int signal;
void *cookie;
/*
* This does two things:
@@ -864,33 +942,24 @@ static void exit_notify(struct task_struct *tsk, int group_dead)
!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 (!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);
}
signal = tracehook_notify_death(tsk, &cookie, group_dead);
if (signal >= 0)
signal = do_notify_parent(tsk, signal);
state = EXIT_ZOMBIE;
if (task_detached(tsk) && likely(!tsk->ptrace))
state = EXIT_DEAD;
tsk->exit_state = state;
tsk->exit_state = signal == DEATH_REAP ? EXIT_DEAD : EXIT_ZOMBIE;
/* mt-exec, de_thread() is waiting for us */
if (thread_group_leader(tsk) &&
tsk->signal->notify_count < 0 &&
tsk->signal->group_exit_task)
tsk->signal->group_exit_task &&
tsk->signal->notify_count < 0)
wake_up_process(tsk->signal->group_exit_task);
write_unlock_irq(&tasklist_lock);
tracehook_report_death(tsk, signal, cookie, group_dead);
/* If the process is dead, release it - nobody will wait for it */
if (state == EXIT_DEAD)
if (signal == DEATH_REAP)
release_task(tsk);
}
@@ -919,39 +988,6 @@ static void check_stack_usage(void)
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;
@@ -966,10 +1002,7 @@ NORET_TYPE void do_exit(long code)
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
@@ -1014,7 +1047,6 @@ NORET_TYPE void do_exit(long code)
}
group_dead = atomic_dec_and_test(&tsk->signal->live);
if (group_dead) {
exit_child_reaper(tsk);
hrtimer_cancel(&tsk->signal->real_timer);
exit_itimers(tsk->signal);
}
@@ -1176,13 +1208,6 @@ static int eligible_child(enum pid_type type, struct pid *pid, int options,
return 0;
}
/*
* Do not consider detached threads that are
* not ptraced:
*/
if (task_detached(p) && !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:
@@ -1193,14 +1218,10 @@ static int eligible_child(enum pid_type type, struct pid *pid, int options,
return 0;
err = security_task_wait(p);
if (likely(!err))
return 1;
if (err)
return err;
if (type != PIDTYPE_PID)
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,
@@ -1234,7 +1255,7 @@ 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)
{
@@ -1242,7 +1263,10 @@ static int wait_task_zombie(struct task_struct *p, int noreap,
int retval, status, traced;
pid_t pid = task_pid_vnr(p);
if (unlikely(noreap)) {
if (!likely(options & WEXITED))
return 0;
if (unlikely(options & WNOWAIT)) {
uid_t uid = p->uid;
int exit_code = p->exit_code;
int why, status;
@@ -1323,6 +1347,8 @@ static int wait_task_zombie(struct task_struct *p, int noreap,
psig->coublock +=
task_io_get_oublock(p) +
sig->oublock + sig->coublock;
task_io_accounting_add(&psig->ioac, &p->ioac);
task_io_accounting_add(&psig->ioac, &sig->ioac);
spin_unlock_irq(&p->parent->sighand->siglock);
}
@@ -1392,21 +1418,24 @@ static int wait_task_zombie(struct task_struct *p, int noreap,
* 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.
@@ -1417,7 +1446,7 @@ static int wait_task_stopped(struct task_struct *p,
if (!exit_code)
goto unlock_sig;
if (!noreap)
if (!unlikely(options & WNOWAIT))
p->exit_code = 0;
uid = p->uid;
@@ -1435,10 +1464,10 @@ unlock_sig:
*/
get_task_struct(p);
pid = task_pid_vnr(p);
why = (p->ptrace & PT_PTRACED) ? CLD_TRAPPED : CLD_STOPPED;
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);
@@ -1472,7 +1501,7 @@ unlock_sig:
* 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)
{
@@ -1480,6 +1509,9 @@ static int wait_task_continued(struct task_struct *p, int noreap,
pid_t pid;
uid_t uid;
if (!unlikely(options & WCONTINUED))
return 0;
if (!(p->signal->flags & SIGNAL_STOP_CONTINUED))
return 0;
@@ -1489,7 +1521,7 @@ static int wait_task_continued(struct task_struct *p, int noreap,
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);
@@ -1515,89 +1547,161 @@ static int wait_task_continued(struct task_struct *p, int noreap,
return retval;
}
/*
* 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(&current->signal->wait_chldexit,&wait);
repeat:
/* If there is nothing that can match our critier just get out */
/*
* 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.
*/
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 = retval = 0;
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(type, 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(type, 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);
@@ -1605,16 +1709,14 @@ repeat:
} 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(&current->signal->wait_chldexit,&wait);