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locking: More accurate annotations for read_lock()

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On the archs using QUEUED_RWLOCKS, read_lock() is not always a recursive
read lock, actually it's only recursive if in_interrupt() is true. So
change the annotation accordingly to catch more deadlocks.

Note we used to treat read_lock() as pure recursive read locks in
lib/locking-seftest.c, and this is useful, especially for the lockdep
development selftest, so we keep this via a variable to force switching
lock annotation for read_lock().

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200807074238.1632519-2-boqun.feng@gmail.com
This commit is contained in:
Boqun Feng
2020-08-07 15:42:20 +08:00
committed by Peter Zijlstra
parent 92b4e9f11a
commit e918188611
3 changed files with 47 additions and 1 deletions
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11
lib/locking-selftest.c
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@@ -28,6 +28,7 @@
* Change this to 1 if you want to see the failure printouts:
*/
static unsigned int debug_locks_verbose;
unsigned int force_read_lock_recursive;
static DEFINE_WD_CLASS(ww_lockdep);
@@ -1978,6 +1979,11 @@ void locking_selftest(void)
return;
}
/*
* treats read_lock() as recursive read locks for testing purpose
*/
force_read_lock_recursive = 1;
/*
* Run the testsuite:
*/
@@ -2073,6 +2079,11 @@ void locking_selftest(void)
ww_tests();
force_read_lock_recursive = 0;
/*
* queued_read_lock() specific test cases can be put here
*/
if (unexpected_testcase_failures) {
printk("-----------------------------------------------------------------\n");
debug_locks = 0;