Revert "exit: Remove profile_task_exit & profile_munmap"

This reverts commit 2d4bcf886e, which
removed hooks required for Android uid_sys_stats.c.

Bug: 219790626
Change-Id: Icea00bbf9abe2fb17312b25f2d575d29aa360999
[nkapron: resolve conflict with 2873cd31a2 exit: Remove profile_handoff_task]
Signed-off-by: Neill Kapron <nkapron@google.com>

include/linux/profile.h

@@ -31,6 +31,11 @@ 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;
@@ -61,6 +66,15 @@ 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
@@ -85,6 +99,18 @@ 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

@@ -811,6 +811,7 @@ void __noreturn do_exit(long code)
 
 	WARN_ON(tsk->plug);
 
+	profile_task_exit(tsk);
 	kcov_task_exit(tsk);
 	kmsan_task_exit(tsk);
 

kernel/profile.c

@@ -136,6 +136,59 @@ 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);
+
 #if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS)
 /*
  * Each cpu has a pair of open-addressed hashtables for pending

mm/mmap.c

@@ -2802,6 +2802,7 @@ 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);
 }