Commit 8c2f5266 authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

umd: Remove exit_umh 

The bpfilter 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.

v1: https://lkml.kernel.org/r/87bll6dlte.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/87y2o53abg.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-15-ebiederm@xmission.com


Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Tested-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
parent e80eb1dc

include/linux/sched.h

+0 −1
Original line number Diff line number Diff line
@@ -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 */

include/linux/usermode_driver.h

+0 −16
Original line number Diff line number Diff line
@@ -4,26 +4,10 @@ 
#include <linux/umh.h>

#include <linux/path.h>



#ifdef CONFIG_BPFILTER

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);

}

#else

static inline void exit_umh(struct task_struct *tsk)

{

}

#endif



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;

};

kernel/exit.c

+0 −3
Original line number Diff line number Diff line
@@ -63,7 +63,6 @@ 
#include <linux/random.h>

#include <linux/rcuwait.h>

#include <linux/compat.h>

#include <linux/usermode_driver.h>



#include <linux/uaccess.h>

#include <asm/unistd.h>
@@ -805,8 +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

kernel/usermode_driver.c

+0 −28
Original line number Diff line number Diff line
@@ -9,9 +9,6 @@ 
#include <linux/task_work.h>

#include <linux/usermode_driver.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;
@@ -134,7 +131,6 @@ 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;

}
@@ -182,11 +178,6 @@ 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);
@@ -194,23 +185,4 @@ out: 
}

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);

}

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