Commit dcf560c5 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds

[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
...@@ -1393,20 +1393,22 @@ static void zap_process(struct task_struct *start) ...@@ -1393,20 +1393,22 @@ static void zap_process(struct task_struct *start)
unlock_task_sighand(start, &flags); 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 *g, *p;
struct task_struct *tsk = current; int err = -EAGAIN;
struct completion *vfork_done = tsk->vfork_done;
spin_lock_irq(&tsk->sighand->siglock);
/* if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT)) {
* Make sure nobody is waiting for us to release the VM, tsk->signal->flags = SIGNAL_GROUP_EXIT;
* otherwise we can deadlock when we wait on each other tsk->signal->group_exit_code = exit_code;
*/ tsk->signal->group_stop_count = 0;
if (vfork_done) { err = 0;
tsk->vfork_done = NULL;
complete(vfork_done);
} }
spin_unlock_irq(&tsk->sighand->siglock);
if (err)
return err;
rcu_read_lock(); rcu_read_lock();
for_each_process(g) { for_each_process(g) {
...@@ -1420,22 +1422,43 @@ static void zap_threads(struct mm_struct *mm) ...@@ -1420,22 +1422,43 @@ static void zap_threads(struct mm_struct *mm)
} while ((p = next_thread(p)) != g); } while ((p = next_thread(p)) != g);
} }
rcu_read_unlock(); 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; int core_waiters;
init_completion(&mm->core_done);
init_completion(&startup_done);
mm->core_startup_done = &startup_done; mm->core_startup_done = &startup_done;
zap_threads(mm); core_waiters = zap_threads(tsk, mm, exit_code);
core_waiters = mm->core_waiters;
up_write(&mm->mmap_sem); 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) if (core_waiters)
wait_for_completion(&startup_done); wait_for_completion(&startup_done);
fail:
BUG_ON(mm->core_waiters); BUG_ON(mm->core_waiters);
return core_waiters;
} }
int do_coredump(long signr, int exit_code, struct pt_regs * regs) 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) ...@@ -1469,22 +1492,9 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
} }
mm->dumpable = 0; mm->dumpable = 0;
retval = -EAGAIN; retval = coredump_wait(exit_code);
spin_lock_irq(&current->sighand->siglock); if (retval < 0)
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);
goto fail; goto fail;
}
init_completion(&mm->core_done);
coredump_wait(mm);
/* /*
* Clear any false indication of pending signals that might * Clear any false indication of pending signals that might
......
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