Commit 2d4bcf88 authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

exit: Remove profile_task_exit & profile_munmap 



When I say remove I mean remove.  All profile_task_exit and
profile_munmap do is call a blocking notifier chain.  The helpers
profile_task_register and profile_task_unregister are not called
anywhere in the tree.  Which means this is all dead code.

So remove the dead code and make it easier to read do_exit.

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lkml.kernel.org/r/20220103213312.9144-1-ebiederm@xmission.com


Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
parent 6410349e

include/linux/profile.h

+0 −26
Original line number Diff line number Diff line
@@ -31,11 +31,6 @@ static inline int create_proc_profile(void) 
}

#endif



enum profile_type {

	PROFILE_TASK_EXIT,

	PROFILE_MUNMAP

};



#ifdef CONFIG_PROFILING



extern int prof_on __read_mostly;
@@ -66,23 +61,14 @@ static inline void profile_hit(int type, void *ip) 
struct task_struct;

struct mm_struct;



/* task is in do_exit() */

void profile_task_exit(struct task_struct * task);



/* task is dead, free task struct ? Returns 1 if

 * the task was taken, 0 if the task should be freed.

 */

int profile_handoff_task(struct task_struct * task);



/* sys_munmap */

void profile_munmap(unsigned long addr);



int task_handoff_register(struct notifier_block * n);

int task_handoff_unregister(struct notifier_block * n);



int profile_event_register(enum profile_type, struct notifier_block * n);

int profile_event_unregister(enum profile_type, struct notifier_block * n);



#else



#define prof_on 0
@@ -117,19 +103,7 @@ static inline int task_handoff_unregister(struct notifier_block * n) 
	return -ENOSYS;

}



static inline int profile_event_register(enum profile_type t, struct notifier_block * n)

{

	return -ENOSYS;

}



static inline int profile_event_unregister(enum profile_type t, struct notifier_block * n)

{

	return -ENOSYS;

}



#define profile_task_exit(a) do { } while (0)

#define profile_handoff_task(a) (0)

#define profile_munmap(a) do { } while (0)



#endif /* CONFIG_PROFILING */

kernel/exit.c

+0 −1
Original line number Diff line number Diff line
@@ -751,7 +751,6 @@ void __noreturn do_exit(long code) 
	 */

	force_uaccess_begin();



	profile_task_exit(tsk);

	kcov_task_exit(tsk);



	coredump_task_exit(tsk);

kernel/profile.c

+0 −50
Original line number Diff line number Diff line
@@ -135,14 +135,7 @@ int __ref profile_init(void) 


/* Profile event notifications */



static BLOCKING_NOTIFIER_HEAD(task_exit_notifier);

static ATOMIC_NOTIFIER_HEAD(task_free_notifier);

static BLOCKING_NOTIFIER_HEAD(munmap_notifier);



void profile_task_exit(struct task_struct *task)

{

	blocking_notifier_call_chain(&task_exit_notifier, 0, task);

}



int profile_handoff_task(struct task_struct *task)

{
@@ -151,11 +144,6 @@ int profile_handoff_task(struct task_struct *task) 
	return (ret == NOTIFY_OK) ? 1 : 0;

}



void profile_munmap(unsigned long addr)

{

	blocking_notifier_call_chain(&munmap_notifier, 0, (void *)addr);

}



int task_handoff_register(struct notifier_block *n)

{

	return atomic_notifier_chain_register(&task_free_notifier, n);
@@ -168,44 +156,6 @@ int task_handoff_unregister(struct notifier_block *n) 
}

EXPORT_SYMBOL_GPL(task_handoff_unregister);



int profile_event_register(enum profile_type type, struct notifier_block *n)

{

	int err = -EINVAL;



	switch (type) {

	case PROFILE_TASK_EXIT:

		err = blocking_notifier_chain_register(

				&task_exit_notifier, n);

		break;

	case PROFILE_MUNMAP:

		err = blocking_notifier_chain_register(

				&munmap_notifier, n);

		break;

	}



	return err;

}

EXPORT_SYMBOL_GPL(profile_event_register);



int profile_event_unregister(enum profile_type type, struct notifier_block *n)

{

	int err = -EINVAL;



	switch (type) {

	case PROFILE_TASK_EXIT:

		err = blocking_notifier_chain_unregister(

				&task_exit_notifier, n);

		break;

	case PROFILE_MUNMAP:

		err = blocking_notifier_chain_unregister(

				&munmap_notifier, n);

		break;

	}



	return err;

}

EXPORT_SYMBOL_GPL(profile_event_unregister);



#if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS)

/*

 * Each cpu has a pair of open-addressed hashtables for pending

mm/mmap.c

+0 −1
Original line number Diff line number Diff line
@@ -2928,7 +2928,6 @@ EXPORT_SYMBOL(vm_munmap); 
SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len)

{

	addr = untagged_addr(addr);

	profile_munmap(addr);

	return __vm_munmap(addr, len, true);

}