diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/exit.c | 6 | ||||
| -rw-r--r-- | kernel/fork.c | 60 |
2 files changed, 27 insertions, 39 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index cece89f80ab..97f609f574b 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -507,10 +507,9 @@ void put_files_struct(struct files_struct *files) } } -EXPORT_SYMBOL(put_files_struct); - -void reset_files_struct(struct task_struct *tsk, struct files_struct *files) +void reset_files_struct(struct files_struct *files) { + struct task_struct *tsk = current; struct files_struct *old; old = tsk->files; @@ -519,7 +518,6 @@ void reset_files_struct(struct task_struct *tsk, struct files_struct *files) task_unlock(tsk); put_files_struct(old); } -EXPORT_SYMBOL(reset_files_struct); void exit_files(struct task_struct *tsk) { diff --git a/kernel/fork.c b/kernel/fork.c index 89fe414645e..c674aa8d3c3 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -521,7 +521,7 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm) * Allocate a new mm structure and copy contents from the * mm structure of the passed in task structure. */ -static struct mm_struct *dup_mm(struct task_struct *tsk) +struct mm_struct *dup_mm(struct task_struct *tsk) { struct mm_struct *mm, *oldmm = current->mm; int err; @@ -805,12 +805,6 @@ static int copy_files(unsigned long clone_flags, struct task_struct * tsk) goto out; } - /* - * Note: we may be using current for both targets (See exec.c) - * This works because we cache current->files (old) as oldf. Don't - * break this. - */ - tsk->files = NULL; newf = dup_fd(oldf, &error); if (!newf) goto out; @@ -846,34 +840,6 @@ static int copy_io(unsigned long clone_flags, struct task_struct *tsk) return 0; } -/* - * Helper to unshare the files of the current task. - * We don't want to expose copy_files internals to - * the exec layer of the kernel. - */ - -int unshare_files(void) -{ - struct files_struct *files = current->files; - int rc; - - BUG_ON(!files); - - /* This can race but the race causes us to copy when we don't - need to and drop the copy */ - if(atomic_read(&files->count) == 1) - { - atomic_inc(&files->count); - return 0; - } - rc = copy_files(0, current); - if(rc) - current->files = files; - return rc; -} - -EXPORT_SYMBOL(unshare_files); - static int copy_sighand(unsigned long clone_flags, struct task_struct *tsk) { struct sighand_struct *sig; @@ -1811,3 +1777,27 @@ bad_unshare_cleanup_thread: bad_unshare_out: return err; } + +/* + * Helper to unshare the files of the current task. + * We don't want to expose copy_files internals to + * the exec layer of the kernel. + */ + +int unshare_files(struct files_struct **displaced) +{ + struct task_struct *task = current; + struct files_struct *copy = NULL; + int error; + + error = unshare_fd(CLONE_FILES, ©); + if (error || !copy) { + *displaced = NULL; + return error; + } + *displaced = task->files; + task_lock(task); + task->files = copy; + task_unlock(task); + return 0; +} |