From e918188611f073063415f40fae568fa4d86d9044 Mon Sep 17 00:00:00 2001 From: Boqun Feng Date: Fri, 7 Aug 2020 15:42:20 +0800 Subject: locking: More accurate annotations for read_lock() 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 Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20200807074238.1632519-2-boqun.feng@gmail.com --- lib/locking-selftest.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'lib/locking-selftest.c') diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c index 14f44f59e733..caadc4dd3368 100644 --- a/lib/locking-selftest.c +++ b/lib/locking-selftest.c @@ -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; -- cgit v1.2.3