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Commit dcf560c5 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
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[PATCH] coredump: some code relocations 



This is a preparation for the next patch.  No functional changes.
Basically, this patch moves '->flags & SIGNAL_GROUP_EXIT' check into
zap_threads(), and 'complete(vfork_done)' into coredump_wait outside of
->mmap_sem protected area.

Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 7b1c6154

fs/exec.c

+40 −30
Original line number Diff line number Diff line
@@ -1393,20 +1393,22 @@ static void zap_process(struct task_struct *start) 
	unlock_task_sighand(start, &flags);

}



static void zap_threads(struct mm_struct *mm)

static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm,

				int exit_code)

{

	struct task_struct *g, *p;

	struct task_struct *tsk = current;

	struct completion *vfork_done = tsk->vfork_done;

	int err = -EAGAIN;



	/*

	 * 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);

	spin_lock_irq(&tsk->sighand->siglock);

	if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT)) {

		tsk->signal->flags = SIGNAL_GROUP_EXIT;

		tsk->signal->group_exit_code = exit_code;

		tsk->signal->group_stop_count = 0;

		err = 0;

	}

	spin_unlock_irq(&tsk->sighand->siglock);

	if (err)

		return err;



	rcu_read_lock();

	for_each_process(g) {
@@ -1420,22 +1422,43 @@ static void zap_threads(struct mm_struct *mm) 
		} while ((p = next_thread(p)) != g);

	}

	rcu_read_unlock();



	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)
@@ -1469,22 +1492,9 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs) 
	}

	mm->dumpable = 0;



	retval = -EAGAIN;

	spin_lock_irq(&current->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(&current->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