[14/14] umd: Remove exit_umh

Commit Message

Eric W. Biederman June 26, 2020, 12:59 p.m. UTC

The bffilter code no longer uses the umd_info.cleanup callback.  This
callback is what exit_umh exists to call.  So remove exit_umh and all
of it's associated booking.

Signed-off-by: "Eric W. Biederman" <[e-mail]>
---
 include/linux/sched.h |  9 ---------
 include/linux/umd.h   |  2 --
 kernel/exit.c         |  2 --
 kernel/umd.c          | 28 ----------------------------
 4 files changed, 41 deletions(-)

Patch

diff --git a/include/linux/sched.h b/include/linux/sched.h
index b62e6aaf28f0..edb2020875ad 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1511,7 +1511,6 @@  extern struct pid *cad_pid;
 #define PF_KTHREAD		0x00200000	/* I am a kernel thread */
 #define PF_RANDOMIZE		0x00400000	/* Randomize virtual address space */
 #define PF_SWAPWRITE		0x00800000	/* Allowed to write to swap */
-#define PF_UMH			0x02000000	/* I'm an Usermodehelper process */
 #define PF_NO_SETAFFINITY	0x04000000	/* Userland is not allowed to meddle with cpus_mask */
 #define PF_MCE_EARLY		0x08000000      /* Early kill for mce process policy */
 #define PF_MEMALLOC_NOCMA	0x10000000	/* All allocation request will have _GFP_MOVABLE cleared */
@@ -2020,14 +2019,6 @@  static inline void rseq_execve(struct task_struct *t)
 
 #endif
 
-void __exit_umh(struct task_struct *tsk);
-
-static inline void exit_umh(struct task_struct *tsk)
-{
-	if (unlikely(tsk->flags & PF_UMH))
-		__exit_umh(tsk);
-}
-
 #ifdef CONFIG_DEBUG_RSEQ
 
 void rseq_syscall(struct pt_regs *regs);
diff --git a/include/linux/umd.h b/include/linux/umd.h
index 1c4579d79bce..71d8f4a41ad7 100644
--- a/include/linux/umd.h
+++ b/include/linux/umd.h
@@ -8,8 +8,6 @@  struct umd_info {
 	const char *driver_name;
 	struct file *pipe_to_umh;
 	struct file *pipe_from_umh;
-	struct list_head list;
-	void (*cleanup)(struct umd_info *info);
 	struct path wd;
 	struct pid *tgid;
 };
diff --git a/kernel/exit.c b/kernel/exit.c
index 671d5066b399..42f079eb71e5 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -804,8 +804,6 @@  void __noreturn do_exit(long code)
 	exit_task_namespaces(tsk);
 	exit_task_work(tsk);
 	exit_thread(tsk);
-	if (group_dead)
-		exit_umh(tsk);
 
 	/*
 	 * Flush inherited counters to the parent - before the parent
diff --git a/kernel/umd.c b/kernel/umd.c
index 0db9ce3f56c9..de2f542191e5 100644
--- a/kernel/umd.c
+++ b/kernel/umd.c
@@ -8,9 +8,6 @@ 
 #include <linux/fs_struct.h>
 #include <linux/umd.h>
 
-static LIST_HEAD(umh_list);
-static DEFINE_MUTEX(umh_list_lock);
-
 static struct vfsmount *blob_to_mnt(const void *data, size_t len, const char *name)
 {
 	struct file_system_type *type;
@@ -129,7 +126,6 @@  static int umd_setup(struct subprocess_info *info, struct cred *new)
 	umd_info->pipe_to_umh = to_umh[1];
 	umd_info->pipe_from_umh = from_umh[0];
 	umd_info->tgid = get_pid(task_tgid(current));
-	current->flags |= PF_UMH;
 	return 0;
 }
 
@@ -177,11 +173,6 @@  int fork_usermode_driver(struct umd_info *info)
 		goto out;
 
 	err = call_usermodehelper_exec(sub_info, UMH_WAIT_EXEC);
-	if (!err) {
-		mutex_lock(&umh_list_lock);
-		list_add(&info->list, &umh_list);
-		mutex_unlock(&umh_list_lock);
-	}
 out:
 	if (argv)
 		argv_free(argv);
@@ -189,23 +180,4 @@  int fork_usermode_driver(struct umd_info *info)
 }
 EXPORT_SYMBOL_GPL(fork_usermode_driver);
 
-void __exit_umh(struct task_struct *tsk)
-{
-	struct umd_info *info;
-	struct pid *tgid = task_tgid(tsk);
-
-	mutex_lock(&umh_list_lock);
-	list_for_each_entry(info, &umh_list, list) {
-		if (info->tgid == tgid) {
-			list_del(&info->list);
-			mutex_unlock(&umh_list_lock);
-			goto out;
-		}
-	}
-	mutex_unlock(&umh_list_lock);
-	return;
-out:
-	if (info->cleanup)
-		info->cleanup(info);
-}