From e289faa9f12811d3546def3083bac0cc35c54ba8 Mon Sep 17 00:00:00 2001 From: JINHO LIM Date: Thu, 29 Apr 2021 19:22:05 +0900 Subject: [PATCH] ANDROID: vendor_hooks: set debugging data when rt_mutex is working We already applied the 'vendor hook' for Dtask Debugging Information in below issue. (https://issuetracker.google.com/issues/162776704) There are vendor hook call in mutex and rw_semaphore, but not for rt_mutex Please refer to description in details as below, 1. Description This feature writes rt mutex lock waiting information on the task_struct structure. We can check mutex information and mutex owner through the kernel log and custom analysis tools. Like the previous feature in mutex and rw semaphore, added data can be checked by ramdump analysis. 2. Vendor Hook Position 1) VENDOR_DATA - struct task_struct in sched.h VENDOR_DATA_ARRAY(2) [0] : type // RTmutex (Mutex, Rwsem, ...) [1] : pointer // address of lock 2) VENDOR_HOOKs - __rt_mutex_slowlock() in kernel/locking/rtmutex.c 3. Example - SysRq-w in kernel log ... [ 54.164463] [3: kworker/u16:3: 253] kworker/3:2 D12736 418 2 0x00000228 [ 54.164497] [3: kworker/u16:3: 253] RTmutex: 0xffffffc051fa3ae8: owner[sh :9003] [ 54.167812] [3: kworker/u16:3: 253] sh D12848 9003 6900 0x04000200 [ 54.167824] [3: kworker/u16:3: 253] RTmutex: 0xffffffc051fa3b08: owner[kworker/3:2 :418] ... Bug: 186567468 Signed-off-by: JINHO LIM Change-Id: I93f9753be0b2c1fa1a6eaea09379d54c31d1ebcf --- drivers/android/vendor_hooks.c | 2 ++ include/trace/hooks/dtask.h | 8 ++++++++ kernel/locking/rtmutex.c | 3 +++ 3 files changed, 13 insertions(+) diff --git a/drivers/android/vendor_hooks.c b/drivers/android/vendor_hooks.c index bd2c06958e6b..7fb8f5276264 100644 --- a/drivers/android/vendor_hooks.c +++ b/drivers/android/vendor_hooks.c @@ -63,6 +63,8 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_alter_rwsem_list_add); EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_alter_futex_plist_add); EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_mutex_wait_start); EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_mutex_wait_finish); +EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_rtmutex_wait_start); +EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_rtmutex_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); diff --git a/include/trace/hooks/dtask.h b/include/trace/hooks/dtask.h index 8856bdceed06..eb722ab079cd 100644 --- a/include/trace/hooks/dtask.h +++ b/include/trace/hooks/dtask.h @@ -19,6 +19,14 @@ DECLARE_HOOK(android_vh_mutex_wait_finish, TP_PROTO(struct mutex *lock), TP_ARGS(lock)); +struct rt_mutex; +DECLARE_HOOK(android_vh_rtmutex_wait_start, + TP_PROTO(struct rt_mutex *lock), + TP_ARGS(lock)); +DECLARE_HOOK(android_vh_rtmutex_wait_finish, + TP_PROTO(struct rt_mutex *lock), + TP_ARGS(lock)); + struct rw_semaphore; DECLARE_HOOK(android_vh_rwsem_read_wait_start, TP_PROTO(struct rw_semaphore *sem), diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index 48fff6437901..c4d261009eca 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -19,6 +19,7 @@ #include #include #include +#include #include "rtmutex_common.h" @@ -1150,6 +1151,7 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state, { int ret = 0; + trace_android_vh_rtmutex_wait_start(lock); for (;;) { /* Try to acquire the lock: */ if (try_to_take_rt_mutex(lock, current, waiter)) @@ -1179,6 +1181,7 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state, set_current_state(state); } + trace_android_vh_rtmutex_wait_finish(lock); __set_current_state(TASK_RUNNING); return ret; }