From 4b87d7254bc8a9d31fcdd3e134c4651639144c9b Mon Sep 17 00:00:00 2001
From: heshuai1 <heshuai1@xiaomi.com>
Date: Wed, 19 May 2021 18:45:44 +0800
Subject: [PATCH] ANDROID: user: Add vendor hook to user for GKI purpose

In order to implement our scheduling tuning policy in certain cases, we
need to initialize the variables that we have defined in the
user_struct. To achieve this, we will add a vendor hook to user.c at
alloc_uid, which will ensure that our own logic is executed during the
initialization of the user_struct.

Bug: 187458531

Signed-off-by: heshuai1 <heshuai1@xiaomi.com>
Change-Id: I078484aac2c3d396aba5971d6d0f491652f3781c
(cherry picked from commit c9b8fa644f45e9c99da85d8947f6c7e06771f205)
(cherry picked from commit 9ac0923ef565e4de4e1f35edcba6fcb7e45948c9)
---
 drivers/android/vendor_hooks.c |  4 ++++
 include/trace/hooks/user.h     | 22 ++++++++++++++++++++++
 kernel/user.c                  |  4 ++++
 3 files changed, 30 insertions(+)
 create mode 100644 include/trace/hooks/user.h

diff --git a/drivers/android/vendor_hooks.c b/drivers/android/vendor_hooks.c
index 557459befc44..cfb6180c8bae 100644
--- a/drivers/android/vendor_hooks.c
+++ b/drivers/android/vendor_hooks.c
@@ -58,6 +58,7 @@
 #include <trace/hooks/thermal.h>
 #include <trace/hooks/audio_usboffload.h>
 #include <trace/hooks/typec.h>
+#include <trace/hooks/user.h>
 
 /*
  * Export tracepoints that act as a bare tracehook (ie: have no trace event
@@ -214,3 +215,6 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_binder_thread_release);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_binder_has_work_ilocked);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_binder_read_done);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_binder_preset);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_alloc_uid);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_free_user);
+
diff --git a/include/trace/hooks/user.h b/include/trace/hooks/user.h
new file mode 100644
index 000000000000..773eed2ea75a
--- /dev/null
+++ b/include/trace/hooks/user.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM user
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH trace/hooks
+#if !defined(_TRACE_HOOK_USER_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HOOK_USER_H
+#include <trace/hooks/vendor_hooks.h>
+
+struct user_struct;
+DECLARE_HOOK(android_vh_alloc_uid,
+	TP_PROTO(struct user_struct *user),
+	TP_ARGS(user));
+
+DECLARE_HOOK(android_vh_free_user,
+	TP_PROTO(struct user_struct *up),
+	TP_ARGS(up));
+
+#endif /* _TRACE_HOOK_USER_H */
+/* This part must be outside protection */
+#include <trace/define_trace.h>
+
diff --git a/kernel/user.c b/kernel/user.c
index e2cf8c22b539..1dfa806e8739 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -20,6 +20,8 @@
 #include <linux/user_namespace.h>
 #include <linux/proc_ns.h>
 
+#include <trace/hooks/user.h>
+
 /*
  * userns count is 1 for root user, 1 for init_uts_ns,
  * and 1 for... ?
@@ -152,6 +154,7 @@ static void user_epoll_free(struct user_struct *up)
 static void free_user(struct user_struct *up, unsigned long flags)
 	__releases(&uidhash_lock)
 {
+	trace_android_vh_free_user(up);
 	uid_hash_remove(up);
 	spin_unlock_irqrestore(&uidhash_lock, flags);
 	user_epoll_free(up);
@@ -202,6 +205,7 @@ struct user_struct *alloc_uid(kuid_t uid)
 
 		new->uid = uid;
 		refcount_set(&new->__count, 1);
+		trace_android_vh_alloc_uid(new);
 		if (user_epoll_alloc(new)) {
 			kmem_cache_free(uid_cachep, new);
 			return NULL;