diff options
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 147 |
1 files changed, 79 insertions, 68 deletions
diff --git a/fs/exec.c b/fs/exec.c index 0b88bf64614..c8494f513ea 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -666,8 +666,6 @@ static int de_thread(struct task_struct *tsk) * and to assume its PID: */ if (!thread_group_leader(current)) { - struct dentry *proc_dentry1, *proc_dentry2; - /* * Wait for the thread group leader to be a zombie. * It should already be zombie at this point, most @@ -689,10 +687,6 @@ static int de_thread(struct task_struct *tsk) */ current->start_time = leader->start_time; - spin_lock(&leader->proc_lock); - spin_lock(¤t->proc_lock); - proc_dentry1 = proc_pid_unhash(current); - proc_dentry2 = proc_pid_unhash(leader); write_lock_irq(&tasklist_lock); BUG_ON(leader->tgid != current->tgid); @@ -713,7 +707,7 @@ static int de_thread(struct task_struct *tsk) attach_pid(current, PIDTYPE_PID, current->pid); attach_pid(current, PIDTYPE_PGID, current->signal->pgrp); attach_pid(current, PIDTYPE_SID, current->signal->session); - list_add_tail_rcu(¤t->tasks, &init_task.tasks); + list_replace_rcu(&leader->tasks, ¤t->tasks); current->group_leader = current; leader->group_leader = current; @@ -721,7 +715,6 @@ static int de_thread(struct task_struct *tsk) /* Reduce leader to a thread */ detach_pid(leader, PIDTYPE_PGID); detach_pid(leader, PIDTYPE_SID); - list_del_init(&leader->tasks); current->exit_signal = SIGCHLD; @@ -729,10 +722,6 @@ static int de_thread(struct task_struct *tsk) leader->exit_state = EXIT_DEAD; write_unlock_irq(&tasklist_lock); - spin_unlock(&leader->proc_lock); - spin_unlock(¤t->proc_lock); - proc_pid_flush(proc_dentry1); - proc_pid_flush(proc_dentry2); } /* @@ -1379,67 +1368,102 @@ static void format_corename(char *corename, const char *pattern, long signr) *out_ptr = 0; } -static void zap_threads (struct mm_struct *mm) +static void zap_process(struct task_struct *start) { - struct task_struct *g, *p; - struct task_struct *tsk = current; - struct completion *vfork_done = tsk->vfork_done; - int traced = 0; + struct task_struct *t; - /* - * Make sure nobody is waiting for us to release the VM, - * otherwise we can deadlock when we wait on each other - */ - if (vfork_done) { - tsk->vfork_done = NULL; - complete(vfork_done); - } + start->signal->flags = SIGNAL_GROUP_EXIT; + start->signal->group_stop_count = 0; - read_lock(&tasklist_lock); - do_each_thread(g,p) - if (mm == p->mm && p != tsk) { - force_sig_specific(SIGKILL, p); - mm->core_waiters++; - if (unlikely(p->ptrace) && - unlikely(p->parent->mm == mm)) - traced = 1; + t = start; + do { + if (t != current && t->mm) { + t->mm->core_waiters++; + sigaddset(&t->pending.signal, SIGKILL); + signal_wake_up(t, 1); } - while_each_thread(g,p); + } while ((t = next_thread(t)) != start); +} - read_unlock(&tasklist_lock); +static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm, + int exit_code) +{ + struct task_struct *g, *p; + unsigned long flags; + int err = -EAGAIN; + + spin_lock_irq(&tsk->sighand->siglock); + if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT)) { + tsk->signal->group_exit_code = exit_code; + zap_process(tsk); + err = 0; + } + spin_unlock_irq(&tsk->sighand->siglock); + if (err) + return err; - if (unlikely(traced)) { - /* - * We are zapping a thread and the thread it ptraces. - * If the tracee went into a ptrace stop for exit tracing, - * we could deadlock since the tracer is waiting for this - * coredump to finish. Detach them so they can both die. - */ - write_lock_irq(&tasklist_lock); - do_each_thread(g,p) { - if (mm == p->mm && p != tsk && - p->ptrace && p->parent->mm == mm) { - __ptrace_detach(p, 0); + if (atomic_read(&mm->mm_users) == mm->core_waiters + 1) + goto done; + + rcu_read_lock(); + for_each_process(g) { + if (g == tsk->group_leader) + continue; + + p = g; + do { + if (p->mm) { + if (p->mm == mm) { + /* + * p->sighand can't disappear, but + * may be changed by de_thread() + */ + lock_task_sighand(p, &flags); + zap_process(p); + unlock_task_sighand(p, &flags); + } + break; } - } while_each_thread(g,p); - write_unlock_irq(&tasklist_lock); + } while ((p = next_thread(p)) != g); } + rcu_read_unlock(); +done: + return mm->core_waiters; } -static void coredump_wait(struct mm_struct *mm) +static int coredump_wait(int exit_code) { - DECLARE_COMPLETION(startup_done); + struct task_struct *tsk = current; + struct mm_struct *mm = tsk->mm; + struct completion startup_done; + struct completion *vfork_done; int core_waiters; + init_completion(&mm->core_done); + init_completion(&startup_done); mm->core_startup_done = &startup_done; - zap_threads(mm); - core_waiters = mm->core_waiters; + core_waiters = zap_threads(tsk, mm, exit_code); up_write(&mm->mmap_sem); + if (unlikely(core_waiters < 0)) + goto fail; + + /* + * Make sure nobody is waiting for us to release the VM, + * otherwise we can deadlock when we wait on each other + */ + vfork_done = tsk->vfork_done; + if (vfork_done) { + tsk->vfork_done = NULL; + complete(vfork_done); + } + if (core_waiters) wait_for_completion(&startup_done); +fail: BUG_ON(mm->core_waiters); + return core_waiters; } int do_coredump(long signr, int exit_code, struct pt_regs * regs) @@ -1473,22 +1497,9 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs) } mm->dumpable = 0; - retval = -EAGAIN; - spin_lock_irq(¤t->sighand->siglock); - if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) { - current->signal->flags = SIGNAL_GROUP_EXIT; - current->signal->group_exit_code = exit_code; - current->signal->group_stop_count = 0; - retval = 0; - } - spin_unlock_irq(¤t->sighand->siglock); - if (retval) { - up_write(&mm->mmap_sem); + retval = coredump_wait(exit_code); + if (retval < 0) goto fail; - } - - init_completion(&mm->core_done); - coredump_wait(mm); /* * Clear any false indication of pending signals that might |