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Diffstat (limited to 'kernel/usermode_driver.c')
-rw-r--r--kernel/usermode_driver.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/kernel/usermode_driver.c b/kernel/usermode_driver.c
index a86798759f83..f77f8d7ce9e3 100644
--- a/kernel/usermode_driver.c
+++ b/kernel/usermode_driver.c
@@ -133,7 +133,7 @@ static int umd_setup(struct subprocess_info *info, struct cred *new)
set_fs_pwd(current->fs, &umd_info->wd);
umd_info->pipe_to_umh = to_umh[1];
umd_info->pipe_from_umh = from_umh[0];
- umd_info->pid = task_pid_nr(current);
+ umd_info->tgid = get_pid(task_tgid(current));
current->flags |= PF_UMH;
return 0;
}
@@ -146,6 +146,8 @@ static void umd_cleanup(struct subprocess_info *info)
if (info->retval) {
fput(umd_info->pipe_to_umh);
fput(umd_info->pipe_from_umh);
+ put_pid(umd_info->tgid);
+ umd_info->tgid = NULL;
}
}
@@ -155,9 +157,9 @@ static void umd_cleanup(struct subprocess_info *info)
*
* Returns either negative error or zero which indicates success in
* executing a usermode driver. In such case 'struct umd_info *info'
- * is populated with two pipes and a pid of the process. The caller is
+ * is populated with two pipes and a tgid of the process. The caller is
* responsible for health check of the user process, killing it via
- * pid, and closing the pipes when user process is no longer needed.
+ * tgid, and closing the pipes when user process is no longer needed.
*/
int fork_usermode_driver(struct umd_info *info)
{
@@ -165,6 +167,9 @@ int fork_usermode_driver(struct umd_info *info)
char **argv = NULL;
int err;
+ if (WARN_ON_ONCE(info->tgid))
+ return -EBUSY;
+
err = -ENOMEM;
argv = argv_split(GFP_KERNEL, info->driver_name, NULL);
if (!argv)
@@ -192,11 +197,11 @@ EXPORT_SYMBOL_GPL(fork_usermode_driver);
void __exit_umh(struct task_struct *tsk)
{
struct umd_info *info;
- pid_t pid = tsk->pid;
+ struct pid *tgid = task_tgid(tsk);
mutex_lock(&umh_list_lock);
list_for_each_entry(info, &umh_list, list) {
- if (info->pid == pid) {
+ if (info->tgid == tgid) {
list_del(&info->list);
mutex_unlock(&umh_list_lock);
goto out;