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 <jordan.lim@samsung.com>
Change-Id: I93f9753be0b2c1fa1a6eaea09379d54c31d1ebcf
(cherry picked from commit e289faa9f12811d3546def3083bac0cc35c54ba8)
This commit is contained in:
JINHO LIM
2021-04-29 19:22:05 +09:00
committed by jordan.lim@samsung.com
parent 938dc2b9b0
commit 8219786218
3 changed files with 13 additions and 0 deletions

View File

@@ -19,6 +19,7 @@
#include <linux/sched/wake_q.h>
#include <linux/sched/debug.h>
#include <linux/timer.h>
#include <trace/hooks/dtask.h>
#include "rtmutex_common.h"
@@ -1168,6 +1169,7 @@ __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))
@@ -1197,6 +1199,7 @@ __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;
}