diff options
| -rw-r--r-- | kernel/fork.c | 81 |
1 files changed, 51 insertions, 30 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index d1aceaea3f33..8e88b374cee9 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -620,32 +620,17 @@ out: return newf; } -static int copy_files(unsigned long clone_flags, struct task_struct * tsk) +/* + * Allocate a new files structure and copy contents from the + * passed in files structure. + */ +static struct files_struct *dup_fd(struct files_struct *oldf, int *errorp) { - struct files_struct *oldf, *newf; + struct files_struct *newf; struct file **old_fds, **new_fds; - int open_files, size, i, error = 0, expand; + int open_files, size, i, expand; struct fdtable *old_fdt, *new_fdt; - /* - * A background process may not have any files ... - */ - oldf = current->files; - if (!oldf) - goto out; - - if (clone_flags & CLONE_FILES) { - atomic_inc(&oldf->count); - 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; - error = -ENOMEM; newf = alloc_files(); if (!newf) goto out; @@ -674,9 +659,9 @@ static int copy_files(unsigned long clone_flags, struct task_struct * tsk) if (expand) { spin_unlock(&oldf->file_lock); spin_lock(&newf->file_lock); - error = expand_files(newf, open_files-1); + *errorp = expand_files(newf, open_files-1); spin_unlock(&newf->file_lock); - if (error < 0) + if (*errorp < 0) goto out_release; new_fdt = files_fdtable(newf); /* @@ -725,10 +710,8 @@ static int copy_files(unsigned long clone_flags, struct task_struct * tsk) memset(&new_fdt->close_on_exec->fds_bits[start], 0, left); } - tsk->files = newf; - error = 0; out: - return error; + return newf; out_release: free_fdset (new_fdt->close_on_exec, new_fdt->max_fdset); @@ -738,6 +721,40 @@ out_release: goto out; } +static int copy_files(unsigned long clone_flags, struct task_struct * tsk) +{ + struct files_struct *oldf, *newf; + int error = 0; + + /* + * A background process may not have any files ... + */ + oldf = current->files; + if (!oldf) + goto out; + + if (clone_flags & CLONE_FILES) { + atomic_inc(&oldf->count); + 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; + error = -ENOMEM; + newf = dup_fd(oldf, &error); + if (!newf) + goto out; + + tsk->files = newf; + error = 0; +out: + return error; +} + /* * Helper to unshare the files of the current task. * We don't want to expose copy_files internals to @@ -1463,15 +1480,19 @@ static int unshare_vm(unsigned long unshare_flags, struct mm_struct **new_mmp) } /* - * Unsharing of files for tasks created with CLONE_FILES is not supported yet + * Unshare file descriptor table if it is being shared */ static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp) { struct files_struct *fd = current->files; + int error = 0; if ((unshare_flags & CLONE_FILES) && - (fd && atomic_read(&fd->count) > 1)) - return -EINVAL; + (fd && atomic_read(&fd->count) > 1)) { + *new_fdp = dup_fd(fd, &error); + if (!*new_fdp) + return error; + } return 0; } |
