Merge branch 'linus' into cpus4096

1 files changed, 23 insertions, 62 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index ad933bb29ec7..eb4d6470d1d0 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -46,6 +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>
@@ -120,18 +121,7 @@ static void __exit_signal(struct task_struct *tsk)
                 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 */
+                task_io_accounting_add(&sig->ioac, &tsk->ioac);
                 sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
                 sig = NULL; /* Marker for below. */
         }
@@ -162,27 +152,17 @@ static void delayed_put_task_struct(struct rcu_head *rhp)
         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;
         int zap_leader;
 repeat:
+        tracehook_prepare_release_task(p);
         atomic_dec(&p->user->processes);
         proc_flush_task(p);
         write_lock_irq(&tasklist_lock);
-        ptrace_release_task(p);
+        tracehook_finish_release_task(p);
         __exit_signal(p);
 
         /*
@@ -204,6 +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);
@@ -567,8 +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);
         }
 }
@@ -887,7 +872,8 @@ 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:
@@ -924,22 +910,11 @@ 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 < 0 ? EXIT_DEAD : EXIT_ZOMBIE;
 
         /* mt-exec, de_thread() is waiting for us */
         if (thread_group_leader(tsk) &&
@@ -949,8 +924,10 @@ static void exit_notify(struct task_struct *tsk, int group_dead)
 
         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 < 0)
                 release_task(tsk);
 }
 
@@ -1029,10 +1006,7 @@ 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
@@ -1378,21 +1352,8 @@ static int wait_task_zombie(struct task_struct *p, int options,
                 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 */
+                task_io_accounting_add(&psig->ioac, &p->ioac);
+                task_io_accounting_add(&psig->ioac, &sig->ioac);
                 spin_unlock_irq(&p->parent->sighand->siglock);
         }