vserver 1.9.3
[linux-2.6.git] / kernel / exit.c
index 9b652d8..45384fd 100644 (file)
@@ -15,6 +15,7 @@
 #include <linux/tty.h>
 #include <linux/namespace.h>
 #include <linux/security.h>
+#include <linux/cpu.h>
 #include <linux/acct.h>
 #include <linux/file.h>
 #include <linux/binfmts.h>
 #include <linux/profile.h>
 #include <linux/mount.h>
 #include <linux/proc_fs.h>
+#include <linux/mempolicy.h>
+#include <linux/vs_limit.h>
 
 #include <asm/uaccess.h>
+#include <asm/unistd.h>
 #include <asm/pgtable.h>
 #include <asm/mmu_context.h>
 
 extern void sem_exit (void);
 extern struct task_struct *child_reaper;
 
-int getrusage(struct task_struct *, int, struct rusage *);
+int getrusage(struct task_struct *, int, struct rusage __user *);
 
 static void __unhash_process(struct task_struct *p)
 {
        nr_threads--;
        /* tasklist_lock is held, is this sufficient? */
        if (p->vx_info) {
-               atomic_dec(&p->vx_info->cacct.nr_threads);
-               atomic_dec(&p->vx_info->limit.res[RLIMIT_NPROC]);
+               atomic_dec(&p->vx_info->cvirt.nr_threads);
+               vx_nproc_dec(p);
        }
        detach_pid(p, PIDTYPE_PID);
        detach_pid(p, PIDTYPE_TGID);
@@ -59,8 +63,6 @@ void release_task(struct task_struct * p)
        struct dentry *proc_dentry;
 
 repeat: 
-       BUG_ON(p->state < TASK_ZOMBIE);
        atomic_dec(&p->user->processes);
        spin_lock(&p->proc_lock);
        proc_dentry = proc_pid_unhash(p);
@@ -93,12 +95,6 @@ repeat:
                zap_leader = (leader->exit_signal == -1);
        }
 
-       p->parent->cutime += p->utime + p->cutime;
-       p->parent->cstime += p->stime + p->cstime;
-       p->parent->cmin_flt += p->min_flt + p->cmin_flt;
-       p->parent->cmaj_flt += p->maj_flt + p->cmaj_flt;
-       p->parent->cnvcsw += p->nvcsw + p->cnvcsw;
-       p->parent->cnivcsw += p->nivcsw + p->cnivcsw;
        sched_exit(p);
        write_unlock_irq(&tasklist_lock);
        spin_unlock(&p->proc_lock);
@@ -134,16 +130,15 @@ void unhash_process(struct task_struct *p)
 int session_of_pgrp(int pgrp)
 {
        struct task_struct *p;
-       struct list_head *l;
-       struct pid *pid;
        int sid = -1;
 
        read_lock(&tasklist_lock);
-       for_each_task_pid(pgrp, PIDTYPE_PGID, p, l, pid)
+       do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
                if (p->signal->session > 0) {
                        sid = p->signal->session;
                        goto out;
                }
+       } while_each_task_pid(pgrp, PIDTYPE_PGID, p);
        p = find_task_by_pid(pgrp);
        if (p)
                sid = p->signal->session;
@@ -164,11 +159,9 @@ out:
 static int will_become_orphaned_pgrp(int pgrp, task_t *ignored_task)
 {
        struct task_struct *p;
-       struct list_head *l;
-       struct pid *pid;
        int ret = 1;
 
-       for_each_task_pid(pgrp, PIDTYPE_PGID, p, l, pid) {
+       do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
                if (p == ignored_task
                                || p->state >= TASK_ZOMBIE 
                                || p->real_parent->pid == 1)
@@ -178,7 +171,7 @@ static int will_become_orphaned_pgrp(int pgrp, task_t *ignored_task)
                        ret = 0;
                        break;
                }
-       }
+       } while_each_task_pid(pgrp, PIDTYPE_PGID, p);
        return ret;     /* (sighing) "Often!" */
 }
 
@@ -197,10 +190,8 @@ static inline int has_stopped_jobs(int pgrp)
 {
        int retval = 0;
        struct task_struct *p;
-       struct list_head *l;
-       struct pid *pid;
 
-       for_each_task_pid(pgrp, PIDTYPE_PGID, p, l, pid) {
+       do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
                if (p->state != TASK_STOPPED)
                        continue;
 
@@ -216,7 +207,7 @@ static inline int has_stopped_jobs(int pgrp)
 
                retval = 1;
                break;
-       }
+       } while_each_task_pid(pgrp, PIDTYPE_PGID, p);
        return retval;
 }
 
@@ -300,7 +291,7 @@ int allow_signal(int sig)
                   Let the signal code know it'll be handled, so
                   that they don't get converted to SIGKILL or
                   just silently dropped */
-               current->sighand->action[(sig)-1].sa.sa_handler = (void *)2;
+               current->sighand->action[(sig)-1].sa.sa_handler = (void __user *)2;
        }
        recalc_sigpending();
        spin_unlock_irq(&current->sighand->siglock);
@@ -384,7 +375,7 @@ static inline void close_files(struct files_struct * files)
                                struct file * file = xchg(&files->fd[i], NULL);
                                if (file)
                                        filp_close(file, files);
-                               vx_openfd_dec(fd);
+                               // vx_openfd_dec(i);
                        }
                        i++;
                        set >>= 1;
@@ -534,10 +525,8 @@ static inline void choose_new_parent(task_t *p, task_t *reaper, task_t *child_re
         * Make sure we're not reparenting to ourselves and that
         * the parent is not a zombie.
         */
-       if (p == reaper || reaper->state >= TASK_ZOMBIE)
-               p->real_parent = child_reaper;
-       else
-               p->real_parent = reaper;
+       BUG_ON(p == reaper || reaper->state >= TASK_ZOMBIE);
+       p->real_parent = reaper;
        if (p->parent == p->real_parent)
                BUG();
 }
@@ -574,6 +563,14 @@ static inline void reparent_thread(task_t *p, task_t *father, int traced)
                if (p->state == TASK_ZOMBIE && p->exit_signal != -1 &&
                    thread_group_empty(p))
                        do_notify_parent(p, p->exit_signal);
+               else if (p->state == TASK_TRACED) {
+                       /*
+                        * If it was at a trace stop, turn it into
+                        * a normal stop since it's no longer being
+                        * traced.
+                        */
+                       p->state = TASK_STOPPED;
+               }
        }
 
        /*
@@ -599,15 +596,20 @@ static inline void reparent_thread(task_t *p, task_t *father, int traced)
  * group, and if no such member exists, give it to
  * the global child reaper process (ie "init")
  */
-static inline void forget_original_parent(struct task_struct * father)
+static inline void forget_original_parent(struct task_struct * father,
+                                         struct list_head *to_release)
 {
        struct task_struct *p, *reaper = father;
        struct list_head *_p, *_n;
 
        /* FIXME handle vchild_reaper/initpid */
-       reaper = father->group_leader;
-       if (reaper == father)
-               reaper = child_reaper;
+       do {
+               reaper = next_thread(reaper);
+               if (reaper == father) {
+                       reaper = child_reaper;
+                       break;
+               }
+       } while (reaper->state >= TASK_ZOMBIE);
 
        /*
         * There are only two places where our children can be:
@@ -618,16 +620,34 @@ static inline void forget_original_parent(struct task_struct * father)
         * Search them and reparent children.
         */
        list_for_each_safe(_p, _n, &father->children) {
+               int ptrace;
                p = list_entry(_p,struct task_struct,sibling);
+
+               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 */
                        choose_new_parent(p, reaper, child_reaper);
                        reparent_thread(p, father, 0);
                } else {
-                       ptrace_unlink (p);
+                       /* reparent ptraced task to its real parent */
+                       __ptrace_unlink (p);
                        if (p->state == TASK_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->state == TASK_ZOMBIE && p->exit_signal == -1))
+                       list_add(&p->ptrace_list, to_release);
        }
        list_for_each_safe(_p, _n, &father->ptrace_children) {
                p = list_entry(_p,struct task_struct,ptrace_list);
@@ -644,6 +664,7 @@ static void exit_notify(struct task_struct *tsk)
 {
        int state;
        struct task_struct *t;
+       struct list_head ptrace_dead, *_p, *_n;
 
        if (signal_pending(tsk) && !tsk->signal->group_exit
            && !thread_group_empty(tsk)) {
@@ -679,8 +700,10 @@ static void exit_notify(struct task_struct *tsk)
         *      jobs, send them a SIGHUP and then a SIGCONT.  (POSIX 3.2.2.2)
         */
 
-       forget_original_parent(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
@@ -740,33 +763,38 @@ static void exit_notify(struct task_struct *tsk)
        if (tsk->exit_signal == -1 && tsk->ptrace == 0)
                state = TASK_DEAD;
        tsk->state = state;
-       tsk->flags |= PF_DEAD;
 
        /*
-        * In the preemption case it must be impossible for the task
-        * to get runnable again, so use "_raw_" unlock to keep
-        * preempt_count elevated until we schedule().
-        *
-        * To avoid deadlock on SMP, interrupts must be unmasked.  If we
-        * don't, subsequently called functions (e.g, wait_task_inactive()
-        * via release_task()) will spin, with interrupt flags
-        * unwittingly blocked, until the other task sleeps.  That task
-        * may itself be waiting for smp_call_function() to answer and
-        * complete, and with interrupts blocked that will never happen.
+        * Clear these here so that update_process_times() won't try to deliver
+        * itimer, profile or rlimit signals to this task while it is in late exit.
         */
-       _raw_write_unlock(&tasklist_lock);
-       local_irq_enable();
+       tsk->it_virt_value = 0;
+       tsk->it_prof_value = 0;
+       tsk->rlim[RLIMIT_CPU].rlim_cur = RLIM_INFINITY;
+
+       write_unlock_irq(&tasklist_lock);
+
+       list_for_each_safe(_p, _n, &ptrace_dead) {
+               list_del_init(_p);
+               t = list_entry(_p,struct task_struct,ptrace_list);
+               release_task(t);
+       }
 
        /* If the process is dead, release it - nobody will wait for it */
        if (state == TASK_DEAD)
                release_task(tsk);
 
+       /* PF_DEAD causes final put_task_struct after we schedule. */
+       preempt_disable();
+       tsk->flags |= PF_DEAD;
 }
 
 asmlinkage NORET_TYPE void do_exit(long code)
 {
        struct task_struct *tsk = current;
 
+       profile_task_exit(tsk);
+
        if (unlikely(in_interrupt()))
                panic("Aiee, killing interrupt handler!");
        if (unlikely(!tsk->pid))
@@ -783,8 +811,6 @@ asmlinkage NORET_TYPE void do_exit(long code)
                                current->comm, current->pid,
                                preempt_count());
 
-       profile_exit_task(tsk);
        if (unlikely(current->ptrace & PT_TRACE_EXIT)) {
                current->ptrace_message = code;
                ptrace_notify((PTRACE_EVENT_EXIT << 8) | SIGTRAP);
@@ -808,6 +834,10 @@ asmlinkage NORET_TYPE void do_exit(long code)
 
        tsk->exit_code = code;
        exit_notify(tsk);
+#ifdef CONFIG_NUMA
+       mpol_free(tsk->mempolicy);
+       tsk->mempolicy = NULL;
+#endif
        schedule();
        BUG();
        /* Avoid "noreturn function does return".  */
@@ -829,11 +859,8 @@ asmlinkage long sys_exit(int error_code)
        do_exit((error_code&0xff)<<8);
 }
 
-task_t fastcall *next_thread(task_t *p)
+task_t fastcall *next_thread(const task_t *p)
 {
-       struct pid_link *link = p->pids + PIDTYPE_TGID;
-       struct list_head *tmp, *head = &link->pidptr->task_list;
-
 #ifdef CONFIG_SMP
        if (!p->sighand)
                BUG();
@@ -841,11 +868,7 @@ task_t fastcall *next_thread(task_t *p)
                                !rwlock_is_locked(&tasklist_lock))
                BUG();
 #endif
-       tmp = link->pid_chain.next;
-       if (tmp == head)
-               tmp = head->next;
-
-       return pid_task(tmp, PIDTYPE_TGID);
+       return pid_task(p->pids[PIDTYPE_TGID].pid_list.next, PIDTYPE_TGID);
 }
 
 EXPORT_SYMBOL(next_thread);
@@ -933,16 +956,66 @@ static int eligible_child(pid_t pid, int options, task_t *p)
        return 1;
 }
 
+static int wait_noreap_copyout(task_t *p, pid_t pid, uid_t uid,
+                              int why, int status,
+                              struct siginfo __user *infop,
+                              struct rusage __user *rusagep)
+{
+       int retval = rusagep ? getrusage(p, RUSAGE_BOTH, rusagep) : 0;
+       put_task_struct(p);
+       if (!retval)
+               retval = put_user(SIGCHLD, &infop->si_signo);
+       if (!retval)
+               retval = put_user(0, &infop->si_errno);
+       if (!retval)
+               retval = put_user((short)why, &infop->si_code);
+       if (!retval)
+               retval = put_user(pid, &infop->si_pid);
+       if (!retval)
+               retval = put_user(uid, &infop->si_uid);
+       if (!retval)
+               retval = put_user(status, &infop->si_status);
+       if (!retval)
+               retval = pid;
+       return retval;
+}
+
 /*
  * Handle sys_wait4 work for one task in state TASK_ZOMBIE.  We hold
  * read_lock(&tasklist_lock) on entry.  If we return zero, we still hold
  * 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(task_t *p, unsigned int *stat_addr, struct rusage *ru)
+static int wait_task_zombie(task_t *p, int noreap,
+                           struct siginfo __user *infop,
+                           int __user *stat_addr, struct rusage __user *ru)
 {
        unsigned long state;
        int retval;
+       int status;
+
+       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->state != TASK_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) {
+                       why = CLD_EXITED;
+                       status = exit_code >> 8;
+               } else {
+                       why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED;
+                       status = exit_code & 0x7f;
+               }
+               return wait_noreap_copyout(p, pid, uid, why,
+                                          status, infop, ru);
+       }
 
        /*
         * Try to move the task's state to DEAD
@@ -953,12 +1026,45 @@ static int wait_task_zombie(task_t *p, unsigned int *stat_addr, struct rusage *r
                BUG_ON(state != TASK_DEAD);
                return 0;
        }
-       if (unlikely(p->exit_signal == -1 && p->ptrace == 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)) {
+               /*
+                * The resource counters for the group leader are in its
+                * own task_struct.  Those for dead threads in the group
+                * are in its signal_struct, as are those for the child
+                * processes it has previously reaped.  All these
+                * accumulate in the parent's signal_struct c* fields.
+                *
+                * We don't bother to take a lock here to protect these
+                * p->signal fields, because they are only touched by
+                * __exit_signal, which runs with tasklist_lock
+                * write-locked anyway, and so is excluded here.  We do
+                * need to protect the access to p->parent->signal fields,
+                * as other threads in the parent group can be right
+                * here reaping other children at the same time.
+                */
+               spin_lock_irq(&p->parent->sighand->siglock);
+               p->parent->signal->cutime +=
+                       p->utime + p->signal->utime + p->signal->cutime;
+               p->parent->signal->cstime +=
+                       p->stime + p->signal->stime + p->signal->cstime;
+               p->parent->signal->cmin_flt +=
+                       p->min_flt + p->signal->min_flt + p->signal->cmin_flt;
+               p->parent->signal->cmaj_flt +=
+                       p->maj_flt + p->signal->maj_flt + p->signal->cmaj_flt;
+               p->parent->signal->cnvcsw +=
+                       p->nvcsw + p->signal->nvcsw + p->signal->cnvcsw;
+               p->parent->signal->cnivcsw +=
+                       p->nivcsw + p->signal->nivcsw + p->signal->cnivcsw;
+               spin_unlock_irq(&p->parent->sighand->siglock);
+       }
 
        /*
         * Now we are sure this task is interesting, and no other
@@ -967,12 +1073,32 @@ static int wait_task_zombie(task_t *p, unsigned int *stat_addr, struct rusage *r
        read_unlock(&tasklist_lock);
 
        retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
-       if (!retval && stat_addr) {
-               if (p->signal->group_exit)
-                       retval = put_user(p->signal->group_exit_code, stat_addr);
-               else
-                       retval = put_user(p->exit_code, stat_addr);
+       status = p->signal->group_exit
+               ? p->signal->group_exit_code : p->exit_code;
+       if (!retval && stat_addr)
+               retval = put_user(status, stat_addr);
+       if (!retval && infop)
+               retval = put_user(SIGCHLD, &infop->si_signo);
+       if (!retval && infop)
+               retval = put_user(0, &infop->si_errno);
+       if (!retval && infop) {
+               int why;
+
+               if ((status & 0x7f) == 0) {
+                       why = CLD_EXITED;
+                       status >>= 8;
+               } else {
+                       why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
+                       status &= 0x7f;
+               }
+               retval = put_user((short)why, &infop->si_code);
+               if (!retval)
+                       retval = put_user(status, &infop->si_status);
        }
+       if (!retval && infop)
+               retval = put_user(p->pid, &infop->si_pid);
+       if (!retval && infop)
+               retval = put_user(p->uid, &infop->si_uid);
        if (retval) {
                p->state = TASK_ZOMBIE;
                return retval;
@@ -984,20 +1110,18 @@ static int wait_task_zombie(task_t *p, unsigned int *stat_addr, struct rusage *r
                if (p->real_parent != p->parent) {
                        __ptrace_unlink(p);
                        p->state = TASK_ZOMBIE;
-                       /* If this is a detached thread, this is where it goes away.  */
-                       if (p->exit_signal == -1) {
-                               /* release_task takes the lock itself.  */
-                               write_unlock_irq(&tasklist_lock);
-                               release_task (p);
-                       }
-                       else {
+                       /*
+                        * 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);
-                               write_unlock_irq(&tasklist_lock);
+                               if (p->exit_signal != -1)
+                                       p = NULL;
                        }
-                       p = NULL;
                }
-               else
-                       write_unlock_irq(&tasklist_lock);
+               write_unlock_irq(&tasklist_lock);
        }
        if (p != NULL)
                release_task(p);
@@ -1011,8 +1135,9 @@ static int wait_task_zombie(task_t *p, unsigned int *stat_addr, struct rusage *r
  * 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(task_t *p, int delayed_group_leader,
-                            unsigned int *stat_addr, struct rusage *ru)
+static int wait_task_stopped(task_t *p, int delayed_group_leader, int noreap,
+                            struct siginfo __user *infop,
+                            int __user *stat_addr, struct rusage __user *ru)
 {
        int retval, exit_code;
 
@@ -1035,6 +1160,21 @@ static int wait_task_stopped(task_t *p, int delayed_group_leader,
         */
        get_task_struct(p);
        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_STOPPED))
+                       goto bail_ref;
+               return wait_noreap_copyout(p, pid, uid,
+                                          why, (exit_code << 8) | 0x7f,
+                                          infop, ru);
+       }
+
        write_lock_irq(&tasklist_lock);
 
        /*
@@ -1043,7 +1183,7 @@ static int wait_task_stopped(task_t *p, int delayed_group_leader,
         * race with the TASK_ZOMBIE case.
         */
        exit_code = xchg(&p->exit_code, 0);
-       if (unlikely(p->state > TASK_STOPPED)) {
+       if (unlikely(p->state >= TASK_ZOMBIE)) {
                /*
                 * The task resumed and then died.  Let the next iteration
                 * catch it in TASK_ZOMBIE.  Note that exit_code might
@@ -1060,6 +1200,7 @@ static int wait_task_stopped(task_t *p, int delayed_group_leader,
                 * resumed, or it resumed and then died.
                 */
                write_unlock_irq(&tasklist_lock);
+bail_ref:
                put_task_struct(p);
                read_lock(&tasklist_lock);
                return 0;
@@ -1074,6 +1215,20 @@ static int wait_task_stopped(task_t *p, int delayed_group_leader,
        retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
        if (!retval && stat_addr)
                retval = put_user((exit_code << 8) | 0x7f, stat_addr);
+       if (!retval && infop)
+               retval = put_user(SIGCHLD, &infop->si_signo);
+       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);
+       if (!retval && infop)
+               retval = put_user(exit_code, &infop->si_status);
+       if (!retval && infop)
+               retval = put_user(p->pid, &infop->si_pid);
+       if (!retval && infop)
+               retval = put_user(p->uid, &infop->si_uid);
        if (!retval)
                retval = p->pid;
        put_task_struct(p);
@@ -1082,15 +1237,13 @@ static int wait_task_stopped(task_t *p, int delayed_group_leader,
        return retval;
 }
 
-asmlinkage long sys_wait4(pid_t pid,unsigned int * stat_addr, int options, struct rusage * ru)
+static long do_wait(pid_t 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;
 
-       if (options & ~(WNOHANG|WUNTRACED|__WNOTHREAD|__WCLONE|__WALL))
-               return -EINVAL;
-
        add_wait_queue(&current->wait_chldexit,&wait);
 repeat:
        flag = 0;
@@ -1111,30 +1264,69 @@ repeat:
                        flag = 1;
 
                        switch (p->state) {
+                       case TASK_TRACED:
+                               if (!(p->ptrace & PT_PTRACED))
+                                       continue;
+                               /*FALLTHROUGH*/
                        case TASK_STOPPED:
                                if (!(options & WUNTRACED) &&
                                    !(p->ptrace & PT_PTRACED))
                                        continue;
                                retval = wait_task_stopped(p, ret == 2,
+                                                          (options & WNOWAIT),
+                                                          infop,
                                                           stat_addr, ru);
                                if (retval != 0) /* He released the lock.  */
-                                       goto end_wait4;
+                                       goto end;
                                break;
                        case TASK_ZOMBIE:
                                /*
                                 * Eligible but we cannot release it yet:
                                 */
                                if (ret == 2)
+                                       goto check_continued;
+                               if (!likely(options & WEXITED))
                                        continue;
-                               retval = wait_task_zombie(p, stat_addr, ru);
+                               retval = wait_task_zombie(
+                                       p, (options & WNOWAIT),
+                                       infop, stat_addr, ru);
                                if (retval != 0) /* He released the lock.  */
-                                       goto end_wait4;
+                                       goto end;
+                               break;
+                       case TASK_DEAD:
+                               continue;
+                       default:
+check_continued:
+                               if (!unlikely(options & WCONTINUED))
+                                       continue;
+                               if (unlikely(!p->signal))
+                                       continue;
+                               spin_lock_irq(&p->sighand->siglock);
+                               if (p->signal->stop_state < 0) {
+                                       pid_t pid;
+                                       uid_t uid;
+
+                                       if (!(options & WNOWAIT))
+                                               p->signal->stop_state = 0;
+                                       spin_unlock_irq(&p->sighand->siglock);
+                                       pid = p->pid;
+                                       uid = p->uid;
+                                       get_task_struct(p);
+                                       read_unlock(&tasklist_lock);
+                                       retval = wait_noreap_copyout(p, pid,
+                                                       uid, CLD_CONTINUED,
+                                                       SIGCONT, infop, ru);
+                                       BUG_ON(retval == 0);
+                                       goto end;
+                               }
+                               spin_unlock_irq(&p->sighand->siglock);
                                break;
                        }
                }
                if (!flag) {
-                       list_for_each (_p,&tsk->ptrace_children) {
-                               p = list_entry(_p,struct task_struct,ptrace_list);
+                       list_for_each(_p, &tsk->ptrace_children) {
+                               p = list_entry(_p, struct task_struct,
+                                               ptrace_list);
                                if (!eligible_child(pid, options, p))
                                        continue;
                                flag = 1;
@@ -1147,32 +1339,104 @@ repeat:
                if (tsk->signal != current->signal)
                        BUG();
        } while (tsk != current);
+
        read_unlock(&tasklist_lock);
        if (flag) {
                retval = 0;
                if (options & WNOHANG)
-                       goto end_wait4;
+                       goto end;
                retval = -ERESTARTSYS;
                if (signal_pending(current))
-                       goto end_wait4;
+                       goto end;
                schedule();
                goto repeat;
        }
        retval = -ECHILD;
-end_wait4:
+end:
        current->state = TASK_RUNNING;
        remove_wait_queue(&current->wait_chldexit,&wait);
+       if (infop) {
+               if (retval > 0)
+               retval = 0;
+               else {
+                       /*
+                        * For a WNOHANG return, clear out all the fields
+                        * we would set so the user can easily tell the
+                        * difference.
+                        */
+                       if (!retval)
+                               retval = put_user(0, &infop->si_signo);
+                       if (!retval)
+                               retval = put_user(0, &infop->si_errno);
+                       if (!retval)
+                               retval = put_user(0, &infop->si_code);
+                       if (!retval)
+                               retval = put_user(0, &infop->si_pid);
+                       if (!retval)
+                               retval = put_user(0, &infop->si_uid);
+                       if (!retval)
+                               retval = put_user(0, &infop->si_status);
+               }
+       }
        return retval;
 }
 
-#if !defined(__alpha__) && !defined(__ia64__) && \
-    !defined(__arm__) && !defined(__s390__)
+asmlinkage long sys_waitid(int which, pid_t pid,
+                          struct siginfo __user *infop, int options,
+                          struct rusage __user *ru)
+{
+       long ret;
+
+       if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED))
+               return -EINVAL;
+       if (!(options & (WEXITED|WSTOPPED|WCONTINUED)))
+               return -EINVAL;
+
+       switch (which) {
+       case P_ALL:
+               pid = -1;
+               break;
+       case P_PID:
+               if (pid <= 0)
+                       return -EINVAL;
+               break;
+       case P_PGID:
+               if (pid <= 0)
+                       return -EINVAL;
+               pid = -pid;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       ret = do_wait(pid, options, infop, NULL, ru);
+
+       /* avoid REGPARM breakage on x86: */
+       prevent_tail_call(ret);
+       return ret;
+}
+
+asmlinkage long sys_wait4(pid_t pid, int __user *stat_addr,
+                         int options, struct rusage __user *ru)
+{
+       long ret;
+
+       if (options & ~(WNOHANG|WUNTRACED|__WNOTHREAD|__WCLONE|__WALL))
+               return -EINVAL;
+       ret = do_wait(pid, options | WEXITED, NULL, stat_addr, ru);
+
+       /* avoid REGPARM breakage on x86: */
+       prevent_tail_call(ret);
+       return ret;
+}
+
+#ifdef __ARCH_WANT_SYS_WAITPID
 
 /*
  * sys_waitpid() remains for compatibility. waitpid() should be
  * implemented by calling sys_wait4() from libc.a.
  */
-asmlinkage long sys_waitpid(pid_t pid,unsigned int * stat_addr, int options)
+asmlinkage long sys_waitpid(pid_t pid, int __user *stat_addr, int options)
 {
        return sys_wait4(pid, stat_addr, options, NULL);
 }