From 57b59c4a1400fa6c34764eab2e35a8762dc05a09 Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@redhat.com>
Date: Mon, 5 Mar 2012 14:59:13 -0800
Subject: [PATCH] coredump_wait: don't call complete_vfork_done()
Now that CLONE_VFORK is killable, coredump_wait() no longer needs
complete_vfork_done(). zap_threads() should find and kill all tasks with
the same ->mm, this includes our parent if ->vfork_done is set.
mm_release() becomes the only caller, unexport complete_vfork_done().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/exec.c | 14 ++------------
include/linux/sched.h | 1 -
kernel/fork.c | 2 +-
3 files changed, 3 insertions(+), 14 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c
index dccdcec913e9..153dee14fe55 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1926,19 +1926,9 @@ static int coredump_wait(int exit_code, struct core_state *core_state)
core_waiters = zap_threads(tsk, mm, core_state, 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
- */
- if (tsk->vfork_done)
- complete_vfork_done(tsk);
-
- if (core_waiters)
+ if (core_waiters > 0)
wait_for_completion(&core_state->startup);
-fail:
+
return core_waiters;
}
diff --git a/include/linux/sched.h b/include/linux/sched.h
index b6467711f12e..11fcafaf4ae4 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2291,7 +2291,6 @@ extern int do_execve(const char *,
const char __user * const __user *,
const char __user * const __user *, struct pt_regs *);
extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
-extern void complete_vfork_done(struct task_struct *tsk);
struct task_struct *fork_idle(int);
extern void set_task_comm(struct task_struct *tsk, char *from);
diff --git a/kernel/fork.c b/kernel/fork.c
index 892c534ce6e3..44b0e21af50e 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -668,7 +668,7 @@ struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
return mm;
}
-void complete_vfork_done(struct task_struct *tsk)
+static void complete_vfork_done(struct task_struct *tsk)
{
struct completion *vfork;
--
2.34.1