[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: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Oleg Nesterov 2006-06-26 00:26:08 -07:00 committed by Linus Torvalds
parent 7b1c6154fa
commit dcf560c593

View file

@ -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