ANDROID: vendor_hooks: add waiting information for blocked tasks

- Add the hook to get mutex/rwsem information that the tasks
   are waiting for.

 - Add the hook to print messages for sched_show_task.

 - ANDROID_VENDOR_DATA_ARRAY added to task_struct

Bug: 162776704

Signed-off-by: Sangmoon Kim <sangmoon.kim@samsung.com>
Change-Id: Ib436fbd8d0ad509c3b5a73ea8f5170e0761a13fd

drivers/android/vendor_hooks.c

@@ -8,9 +8,17 @@
 
 #define CREATE_TRACE_POINTS
 #include <trace/hooks/vendor_hooks.h>
+#include <trace/hooks/dtask.h>
 
 /*
  * Export tracepoints that act as a bare tracehook (ie: have no trace event
  * associated with them) to allow external modules to probe them.
  */
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_mutex_wait_start);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_mutex_wait_finish);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_rwsem_read_wait_start);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_rwsem_read_wait_finish);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_rwsem_write_wait_start);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_rwsem_write_wait_finish);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_sched_show_task);
 

include/linux/sched.h

@@ -32,6 +32,7 @@
 #include <linux/posix-timers.h>
 #include <linux/rseq.h>
 #include <linux/android_kabi.h>
+#include <linux/android_vendor.h>
 
 /* task_struct member predeclarations (sorted alphabetically): */
 struct audit_context;
@@ -1291,6 +1292,8 @@ struct task_struct {
 	unsigned long			prev_lowest_stack;
 #endif
 
+	ANDROID_VENDOR_DATA_ARRAY(1, 2);
+
 	ANDROID_KABI_RESERVE(1);
 	ANDROID_KABI_RESERVE(2);
 	ANDROID_KABI_RESERVE(3);

include/trace/hooks/dtask.h

@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM dtask
+#define TRACE_INCLUDE_PATH trace/hooks
+
+#if !defined(_TRACE_HOOK_DTASK_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HOOK_DTASK_H
+#include <linux/tracepoint.h>
+#include <trace/hooks/vendor_hooks.h>
+/*
+ * Following tracepoints are not exported in tracefs and provide a
+ * mechanism for vendor modules to hook and extend functionality
+ */
+#if defined(CONFIG_TRACEPOINTS) && defined(CONFIG_ANDROID_VENDOR_HOOKS)
+struct mutex;
+DECLARE_HOOK(android_vh_mutex_wait_start,
+	TP_PROTO(struct mutex *lock),
+	TP_ARGS(lock));
+DECLARE_HOOK(android_vh_mutex_wait_finish,
+	TP_PROTO(struct mutex *lock),
+	TP_ARGS(lock));
+
+struct rw_semaphore;
+DECLARE_HOOK(android_vh_rwsem_read_wait_start,
+	TP_PROTO(struct rw_semaphore *sem),
+	TP_ARGS(sem));
+DECLARE_HOOK(android_vh_rwsem_read_wait_finish,
+	TP_PROTO(struct rw_semaphore *sem),
+	TP_ARGS(sem));
+DECLARE_HOOK(android_vh_rwsem_write_wait_start,
+	TP_PROTO(struct rw_semaphore *sem),
+	TP_ARGS(sem));
+DECLARE_HOOK(android_vh_rwsem_write_wait_finish,
+	TP_PROTO(struct rw_semaphore *sem),
+	TP_ARGS(sem));
+
+struct task_struct;
+DECLARE_HOOK(android_vh_sched_show_task,
+	TP_PROTO(struct task_struct *task),
+	TP_ARGS(task));
+#else
+#define trace_android_vh_mutex_wait_start(lock)
+#define trace_android_vh_mutex_wait_finish(lock)
+#define trace_android_vh_rwsem_read_wait_start(sem)
+#define trace_android_vh_rwsem_read_wait_finish(sem)
+#define trace_android_vh_rwsem_write_wait_start(sem)
+#define trace_android_vh_rwsem_write_wait_finish(sem)
+#define trace_android_vh_sched_show_task(task)
+#endif
+
+#endif /* _TRACE_HOOK_DTASK_H */
+/* This part must be outside protection */
+#include <trace/define_trace.h>

kernel/locking/mutex.c

@@ -36,6 +36,8 @@
 # include "mutex.h"
 #endif
 
+#include <trace/hooks/dtask.h>
+
 void
 __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key)
 {
@@ -1002,6 +1004,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 
 	waiter.task = current;
 
+	trace_android_vh_mutex_wait_start(lock);
 	set_current_state(state);
 	for (;;) {
 		/*
@@ -1057,6 +1060,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 	spin_lock(&lock->wait_lock);
 acquired:
 	__set_current_state(TASK_RUNNING);
+	trace_android_vh_mutex_wait_finish(lock);
 
 	if (use_ww_ctx && ww_ctx) {
 		/*
@@ -1087,6 +1091,7 @@ skip_wait:
 
 err:
 	__set_current_state(TASK_RUNNING);
+	trace_android_vh_mutex_wait_finish(lock);
 	mutex_remove_waiter(lock, &waiter, current);
 err_early_kill:
 	spin_unlock(&lock->wait_lock);

kernel/locking/rwsem.c

@@ -31,6 +31,8 @@
 #include "rwsem.h"
 #include "lock_events.h"
 
+#include <trace/hooks/dtask.h>
+
 /*
  * The least significant 3 bits of the owner value has the following
  * meanings when set.
@@ -1085,6 +1087,7 @@ queue:
 	wake_up_q(&wake_q);
 
 	/* wait to be given the lock */
+	trace_android_vh_rwsem_read_wait_start(sem);
 	for (;;) {
 		set_current_state(state);
 		if (!smp_load_acquire(&waiter.task)) {
@@ -1104,6 +1107,7 @@ queue:
 	}
 
 	__set_current_state(TASK_RUNNING);
+	trace_android_vh_rwsem_read_wait_finish(sem);
 	lockevent_inc(rwsem_rlock);
 	return sem;
 
@@ -1115,6 +1119,7 @@ out_nolock:
 	}
 	raw_spin_unlock_irq(&sem->wait_lock);
 	__set_current_state(TASK_RUNNING);
+	trace_android_vh_rwsem_read_wait_finish(sem);
 	lockevent_inc(rwsem_rlock_fail);
 	return ERR_PTR(-EINTR);
 }
@@ -1209,6 +1214,7 @@ rwsem_down_write_slowpath(struct rw_semaphore *sem, int state)
 
 wait:
 	/* wait until we successfully acquire the lock */
+	trace_android_vh_rwsem_write_wait_start(sem);
 	set_current_state(state);
 	for (;;) {
 		if (rwsem_try_write_lock(sem, wstate)) {
@@ -1268,6 +1274,7 @@ trylock_again:
 		raw_spin_lock_irq(&sem->wait_lock);
 	}
 	__set_current_state(TASK_RUNNING);
+	trace_android_vh_rwsem_write_wait_finish(sem);
 	list_del(&waiter.list);
 	rwsem_disable_reader_optspin(sem, disable_rspin);
 	raw_spin_unlock_irq(&sem->wait_lock);
@@ -1277,6 +1284,7 @@ trylock_again:
 
 out_nolock:
 	__set_current_state(TASK_RUNNING);
+	trace_android_vh_rwsem_write_wait_finish(sem);
 	raw_spin_lock_irq(&sem->wait_lock);
 	list_del(&waiter.list);
 

kernel/sched/core.c

@@ -24,6 +24,9 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/sched.h>
 
+#undef CREATE_TRACE_POINTS
+#include <trace/hooks/dtask.h>
+
 /*
  * Export tracepoints that act as a bare tracehook (ie: have no trace event
  * associated with them) to allow external modules to probe them.
@@ -5930,6 +5933,7 @@ void sched_show_task(struct task_struct *p)
 		(unsigned long)task_thread_info(p)->flags);
 
 	print_worker_info(KERN_INFO, p);
+	trace_android_vh_sched_show_task(p);
 	show_stack(p, NULL);
 	put_task_stack(p);
 }