Merge branch 'linus' into core/softlockup

Conflicts:
	kernel/sysctl.c

1 files changed, 71 insertions, 182 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index efd30ccf3858..32cbf2607cb0 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -46,6 +46,7 @@
 #include <linux/blkdev.h>
 #include <linux/task_io_accounting_ops.h>
 #include <linux/tracehook.h>
+#include <linux/fs_struct.h>
 #include <linux/init_task.h>
 #include <trace/sched.h>
 
@@ -61,11 +62,6 @@ DEFINE_TRACE(sched_process_wait);
 
 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--;
@@ -362,16 +358,12 @@ static void reparent_to_kthreadd(void)
 void __set_special_pids(struct pid *pid)
 {
         struct task_struct *curr = current->group_leader;
-        pid_t nr = pid_nr(pid);
 
-        if (task_session(curr) != pid) {
+        if (task_session(curr) != pid)
                 change_pid(curr, PIDTYPE_SID, pid);
-                set_task_session(curr, nr);
-        }
-        if (task_pgrp(curr) != pid) {
+
+        if (task_pgrp(curr) != pid)
                 change_pid(curr, PIDTYPE_PGID, pid);
-                set_task_pgrp(curr, nr);
-        }
 }
 
 static void set_special_pids(struct pid *pid)
@@ -429,7 +421,6 @@ EXPORT_SYMBOL(disallow_signal);
 void daemonize(const char *name, ...)
 {
         va_list args;
-        struct fs_struct *fs;
         sigset_t blocked;
 
         va_start(args, name);
@@ -462,11 +453,7 @@ void daemonize(const char *name, ...)
 
         /* Become as one with the init task */
 
-        exit_fs(current);       /* current->fs->count--; */
-        fs = init_task.fs;
-        current->fs = fs;
-        atomic_inc(&fs->count);
-
+        daemonize_fs_struct();
         exit_files(current);
         current->files = init_task.files;
         atomic_inc(&current->files->count);
@@ -565,30 +552,6 @@ void exit_files(struct task_struct *tsk)
         }
 }
 
-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)) {
-                path_put(&fs->root);
-                path_put(&fs->pwd);
-                kmem_cache_free(fs_cachep, fs);
-        }
-}
-
-void exit_fs(struct task_struct *tsk)
-{
-        struct fs_struct * fs = tsk->fs;
-
-        if (fs) {
-                task_lock(tsk);
-                tsk->fs = NULL;
-                task_unlock(tsk);
-                put_fs_struct(fs);
-        }
-}
-
-EXPORT_SYMBOL_GPL(exit_fs);
-
 #ifdef CONFIG_MM_OWNER
 /*
  * Task p is exiting and it owned mm, lets find a new owner for it
@@ -732,119 +695,6 @@ static void exit_mm(struct task_struct * tsk)
 }
 
 /*
- * 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);
-
-        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 (same_thread_group(p->real_parent, father))
-                return;
-
-        /* We don't want people slaying init.  */
-        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 (!ptrace_reparented(p) &&
-            p->exit_state == EXIT_ZOMBIE &&
-            !task_detached(p) && thread_group_empty(p))
-                do_notify_parent(p, p->exit_signal);
-
-        kill_orphaned_pgrp(p, father);
-}
-
-/*
  * When we die, we re-parent all our children.
  * Try to give them to another thread in our thread
  * group, and if no such member exists, give it to
@@ -883,17 +733,51 @@ static struct task_struct *find_new_reaper(struct task_struct *father)
         return pid_ns->child_reaper;
 }
 
+/*
+* Any that need to be release_task'd are put on the @dead list.
+ */
+static void reparent_thread(struct task_struct *father, struct task_struct *p,
+                                struct list_head *dead)
+{
+        if (p->pdeath_signal)
+                group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p);
+
+        list_move_tail(&p->sibling, &p->real_parent->children);
+
+        if (task_detached(p))
+                return;
+        /*
+         * If this is a threaded reparent there is no need to
+         * notify anyone anything has happened.
+         */
+        if (same_thread_group(p->real_parent, father))
+                return;
+
+        /* We don't want people slaying init.  */
+        p->exit_signal = SIGCHLD;
+
+        /* If it has exited notify the new parent about this child's death. */
+        if (!p->ptrace &&
+            p->exit_state == EXIT_ZOMBIE && thread_group_empty(p)) {
+                do_notify_parent(p, p->exit_signal);
+                if (task_detached(p)) {
+                        p->exit_state = EXIT_DEAD;
+                        list_move_tail(&p->sibling, dead);
+                }
+        }
+
+        kill_orphaned_pgrp(p, father);
+}
+
 static void forget_original_parent(struct task_struct *father)
 {
         struct task_struct *p, *n, *reaper;
-        LIST_HEAD(ptrace_dead);
+        LIST_HEAD(dead_children);
+
+        exit_ptrace(father);
 
         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;
@@ -901,13 +785,16 @@ static void forget_original_parent(struct task_struct *father)
                         BUG_ON(p->ptrace);
                         p->parent = p->real_parent;
                 }
-                reparent_thread(p, father);
+                reparent_thread(father, p, &dead_children);
         }
-
         write_unlock_irq(&tasklist_lock);
+
         BUG_ON(!list_empty(&father->children));
 
-        ptrace_exit_finish(father, &ptrace_dead);
+        list_for_each_entry_safe(p, n, &dead_children, sibling) {
+                list_del_init(&p->sibling);
+                release_task(p);
+        }
 }
 
 /*
@@ -950,8 +837,7 @@ static void exit_notify(struct task_struct *tsk, int group_dead)
          */
         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->self_exec_id != tsk->parent_exec_id))
                 tsk->exit_signal = SIGCHLD;
 
         signal = tracehook_notify_death(tsk, &cookie, group_dead);
@@ -980,12 +866,9 @@ static void check_stack_usage(void)
 {
         static DEFINE_SPINLOCK(low_water_lock);
         static int lowest_to_date = THREAD_SIZE;
-        unsigned long *n = end_of_stack(current);
         unsigned long free;
 
-        while (*n == 0)
-                n++;
-        free = (unsigned long)n - (unsigned long)end_of_stack(current);
+        free = stack_not_used(current);
 
         if (free >= lowest_to_date)
                 return;
@@ -1420,6 +1303,18 @@ static int wait_task_zombie(struct task_struct *p, int options,
         return retval;
 }
 
+static int *task_stopped_code(struct task_struct *p, bool ptrace)
+{
+        if (ptrace) {
+                if (task_is_stopped_or_traced(p))
+                        return &p->exit_code;
+        } else {
+                if (p->signal->flags & SIGNAL_STOP_STOPPED)
+                        return &p->signal->group_exit_code;
+        }
+        return NULL;
+}
+
 /*
  * Handle sys_wait4 work for one task in state TASK_STOPPED.  We hold
  * read_lock(&tasklist_lock) on entry.  If we return zero, we still hold
@@ -1430,7 +1325,7 @@ 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;
+        int retval, exit_code, *p_code, why;
         uid_t uid = 0; /* unneeded, required by compiler */
         pid_t pid;
 
@@ -1440,22 +1335,16 @@ static int wait_task_stopped(int ptrace, struct task_struct *p,
         exit_code = 0;
         spin_lock_irq(&p->sighand->siglock);
 
-        if (unlikely(!task_is_stopped_or_traced(p)))
-                goto unlock_sig;
-
-        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.
-                 */
+        p_code = task_stopped_code(p, ptrace);
+        if (unlikely(!p_code))
                 goto unlock_sig;
 
-        exit_code = p->exit_code;
+        exit_code = *p_code;
         if (!exit_code)
                 goto unlock_sig;
 
         if (!unlikely(options & WNOWAIT))
-                p->exit_code = 0;
+                *p_code = 0;
 
         /* don't need the RCU readlock here as we're holding a spinlock */
         uid = __task_cred(p)->uid;
@@ -1611,7 +1500,7 @@ static int wait_consider_task(struct task_struct *parent, int ptrace,
          */
         *notask_error = 0;
 
-        if (task_is_stopped_or_traced(p))
+        if (task_stopped_code(p, ptrace))
                 return wait_task_stopped(ptrace, p, options,
                                          infop, stat_addr, ru);
 
@@ -1815,7 +1704,7 @@ SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
                 pid = find_get_pid(-upid);
         } else if (upid == 0) {
                 type = PIDTYPE_PGID;
-                pid = get_pid(task_pgrp(current));
+                pid = get_task_pid(current, PIDTYPE_PGID);
         } else /* upid > 0 */ {
                 type = PIDTYPE_PID;
                 pid = find_get_pid(upid);