From c9b8fa644f45e9c99da85d8947f6c7e06771f205 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

Add the vendor hook to user.c, because of some speical cases related to
our feature, we need to initialize the variables defined by ourselves in
user_struct, so we add the hook at alloc_uid to make sure we can go to
our own logic when the user_struct is about to initialize.

Bug: 187458531

Signed-off-by: heshuai1 <heshuai1@xiaomi.com>
Change-Id: I078484aac2c3d396aba5971d6d0f491652f3781c
---
 drivers/android/vendor_hooks.c |  3 +++
 include/trace/hooks/user.h     | 23 +++++++++++++++++++++++
 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 8e4bb3950cca..9f895faa209b 100644
--- a/drivers/android/vendor_hooks.c
+++ b/drivers/android/vendor_hooks.c
@@ -60,6 +60,7 @@
 #include <trace/hooks/v4l2core.h>
 #include <trace/hooks/v4l2mc.h>
 #include <trace/hooks/scmi.h>
+#include <trace/hooks/user.h>
 
 /*
  * Export tracepoints that act as a bare tracehook (ie: have no trace event
@@ -314,4 +315,6 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_scmi_timeout_sync);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_find_new_ilb);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_force_compatible_pre);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_force_compatible_post);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_alloc_uid);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_free_user);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_set_balance_anon_file_reclaim);
diff --git a/include/trace/hooks/user.h b/include/trace/hooks/user.h
new file mode 100644
index 000000000000..b5b507ccd9c2
--- /dev/null
+++ b/include/trace/hooks/user.h
@@ -0,0 +1,23 @@
+/* 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 <linux/tracepoint.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 ab445fcc07aa..83adc37251fa 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... ?
@@ -139,6 +141,7 @@ static struct user_struct *uid_hash_find(kuid_t uid, struct hlist_head *hashent)
 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);
 	kmem_cache_free(uid_cachep, up);
@@ -190,6 +193,7 @@ struct user_struct *alloc_uid(kuid_t uid)
 
 		new->uid = uid;
 		refcount_set(&new->__count, 1);
+		trace_android_vh_alloc_uid(new);
 		ratelimit_state_init(&new->ratelimit, HZ, 100);
 		ratelimit_set_flags(&new->ratelimit, RATELIMIT_MSG_ON_RELEASE);