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android_kernel_samsung_sm8650/kernel/locking
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Cheng Jui Wang 28df029d53 lockdep: Correct lock_classes index mapping 
A kernel exception was hit when trying to dump /proc/lockdep_chains after
lockdep report "BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!":

Unable to handle kernel paging request at virtual address 00054005450e05c3
...
00054005450e05c3] address between user and kernel address ranges
...
pc : [0xffffffece769b3a8] string+0x50/0x10c
lr : [0xffffffece769ac88] vsnprintf+0x468/0x69c
...
 Call trace:
  string+0x50/0x10c
  vsnprintf+0x468/0x69c
  seq_printf+0x8c/0xd8
  print_name+0x64/0xf4
  lc_show+0xb8/0x128
  seq_read_iter+0x3cc/0x5fc
  proc_reg_read_iter+0xdc/0x1d4

The cause of the problem is the function lock_chain_get_class() will
shift lock_classes index by 1, but the index don't need to be shifted
anymore since commit 01bb6f0af9 ("locking/lockdep: Change the range
of class_idx in held_lock struct") already change the index to start
from 0.

The lock_classes[-1] located at chain_hlocks array. When printing
lock_classes[-1] after the chain_hlocks entries are modified, the
exception happened.

The output of lockdep_chains are incorrect due to this problem too.

Fixes: f611e8cf98 ("lockdep: Take read/write status in consideration when generate chainkey")
Signed-off-by: Cheng Jui Wang <cheng-jui.wang@mediatek.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20220210105011.21712-1-cheng-jui.wang@mediatek.com
2022-02-11 23:30:02 +01:00
..
irqflag-debug.c
lock_events_list.h
lock_events.c
lock_events.h
lockdep_internals.h lockdep: Allow tuning tracing capacity constants. 2021-04-05 20:33:57 +09:00
lockdep_proc.c locking/lockdep: Fix meaningless /proc/lockdep output of lock classes on !CONFIG_PROVE_LOCKING 2021-07-05 10:44:52 +02:00
lockdep_states.h
lockdep.c lockdep: Correct lock_classes index mapping 2022-02-11 23:30:02 +01:00
locktorture.c locktorture,rcutorture,torture: Always log error message 2021-12-07 16:36:17 -08:00
Makefile locking/ww_mutex: Implement rtmutex based ww_mutex API functions 2021-08-17 19:05:26 +02:00
mcs_spinlock.h
mutex-debug.c locking/ww_mutex: Gather mutex_waiter initialization 2021-08-17 19:04:41 +02:00
mutex.c locking: Make owner_on_cpu() into <linux/sched.h> 2021-12-04 10:56:25 +01:00
mutex.h locking/mutex: Move the 'struct mutex_waiter' definition from <linux/mutex.h> to the internal header 2021-08-17 18:24:31 +02:00
osq_lock.c
percpu-rwsem.c
qrwlock.c locking/qrwlock: Cleanup queued_write_lock_slowpath() 2021-05-06 15:33:49 +02:00
qspinlock_paravirt.h
qspinlock_stat.h
qspinlock.c
rtmutex_api.c locking/rtmutex: Add rt_mutex_lock_nest_lock() and rt_mutex_lock_killable(). 2021-12-04 10:56:23 +01:00
rtmutex_common.h locking/rtmutex: Dont dereference waiter lockless 2021-08-25 15:42:32 +02:00
rtmutex.c Merge branch 'locking/urgent' into locking/core 2021-12-18 10:57:03 +01:00
rwbase_rt.c locking/rwbase: Optimize rwbase_read_trylock 2021-10-07 13:51:07 +02:00
rwsem.c Linux 5.16-rc5 2021-12-13 10:48:46 +01:00
semaphore.c locking/semaphore: Add might_sleep() to down_*() family 2021-08-20 12:33:17 +02:00
spinlock_debug.c locking/rwlock: Provide RT variant 2021-08-17 17:50:51 +02:00
spinlock_rt.c locking/rwlocks: introduce write_lock_nested 2022-01-22 08:33:37 +02:00
spinlock.c locking/rwlocks: introduce write_lock_nested 2022-01-22 08:33:37 +02:00
test-ww_mutex.c locking/ww-mutex: Fix uninitialized use of ret in test_aa() 2021-10-01 13:57:49 +02:00
ww_mutex.h locking/ww_mutex: Add rt_mutex based lock type and accessors 2021-08-17 19:05:11 +02:00
ww_rt_mutex.c kernel/locking: Use a pointer in ww_mutex_trylock(). 2021-11-17 14:48:49 +01:00