Reapply "exit: Remove profile_task_exit & profile_munmap"

This reverts commit 3936c80525.

Instead of maintaining this interface which has been removed upstream
let's convert the only user in Android (uid_sys_stats) to a different
callback infrastructure such as hooking into the sched_process_exit()
tracepoint.

Bug: 219790626
Cc: Tiffany Yang <ynaffit@google.com>
Cc: Neill Kapron <nkapron@google.com>
Change-Id: I830330c32829df5fca8d9363cf81b0d0efaac265
Signed-off-by: Carlos Llamas <cmllamas@google.com>

include/linux/profile.h

@@ -24,11 +24,6 @@ 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;
@@ -59,15 +54,6 @@ 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);
-
-/* sys_munmap */
-void profile_munmap(unsigned long addr);
-
-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
@@ -92,18 +78,6 @@ static inline void profile_hit(int type, void *ip)
 	return;
 }
 
-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_munmap(a) do { } while (0)
 
 #endif /* CONFIG_PROFILING */
 

kernel/exit.c

@@ -901,7 +901,6 @@ void __noreturn do_exit(long code)
 	WARN_ON(irqs_disabled());
 	WARN_ON(tsk->plug);
 
-	profile_task_exit(tsk);
 	kcov_task_exit(tsk);
 	kmsan_task_exit(tsk);
 

kernel/profile.c

@@ -114,59 +114,6 @@ int __ref profile_init(void)
 	return -ENOMEM;
 }
 
-/* Profile event notifications */
-
-static BLOCKING_NOTIFIER_HEAD(task_exit_notifier);
-static BLOCKING_NOTIFIER_HEAD(munmap_notifier);
-
-void profile_task_exit(struct task_struct *task)
-{
-	blocking_notifier_call_chain(&task_exit_notifier, 0, task);
-}
-
-void profile_munmap(unsigned long addr)
-{
-	blocking_notifier_call_chain(&munmap_notifier, 0, (void *)addr);
-}
-
-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);
-
 static void do_profile_hits(int type, void *__pc, unsigned int nr_hits)
 {
 	unsigned long pc;

mm/mmap.c

@@ -1077,7 +1077,6 @@ 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);
 }