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: NChristoph Hellwig <hch@lst.de>
Link: https://lkml.kernel.org/r/20220103213312.9144-1-ebiederm@xmission.comSigned-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

include/linux/profile.h

@@ -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

@@ -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

@@ -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

@@ -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);
 }