The commit is pushed to "branch-rh7-3.10.0-1160.80.1.vz7.190.x-ovz" and will
appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-1160.80.1.vz7.190.1
------>
commit 542557c8c8bc38655ef771acca6a7d213a728ccc
Author: Shuah Khan <sk...@linuxfoundation.org>
Date: Fri Feb 26 17:06:58 2021 -0700
ms/lockdep: Add lockdep_assert_not_held()
Some kernel functions must be called without holding a specific lock.
Add lockdep_assert_not_held() to be used in these functions to detect
incorrect calls while holding a lock.
lockdep_assert_not_held() provides the opposite functionality of
lockdep_assert_held() which is used to assert calls that require
holding a specific lock.
Incorporates suggestions from Peter Zijlstra to avoid misfires when
lockdep_off() is employed.
The need for lockdep_assert_not_held() came up in a discussion on
ath10k patch. ath10k_drain_tx() and i915_vma_pin_ww() are examples
of functions that can use lockdep_assert_not_held().
Signed-off-by: Shuah Khan <sk...@linuxfoundation.org>
Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Signed-off-by: Ingo Molnar <mi...@kernel.org>
Link: https://lore.kernel.org/linux-wireless/871rdmu9z9....@codeaurora.org/
(cherry picked from ms commit 3e31f94752e454bdd0ca4a1d046ee21f80c166c5)
Signed-off-by: Konstantin Khorenko <khore...@virtuozzo.com>
---
include/linux/lockdep.h | 9 +++++++--
kernel/lockdep.c | 6 +++++-
2 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 242f69bddecf..1aff47ff71fd 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -367,8 +367,12 @@ extern void lockdep_trace_alloc(gfp_t mask);
#define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0)
-#define lockdep_assert_held(l) do { \
- WARN_ON(debug_locks && !lockdep_is_held(l)); \
+#define lockdep_assert_held(l) do { \
+ WARN_ON(debug_locks && lockdep_is_held(l) == 0); \
+ } while (0)
+
+#define lockdep_assert_not_held(l) do { \
+ WARN_ON(debug_locks && lockdep_is_held(l) == 1); \
} while (0)
#define lockdep_assert_held_exclusive(l) do { \
@@ -435,6 +439,7 @@ struct lock_class_key { };
#define lockdep_is_held_type(l, r) (1)
#define lockdep_assert_held(l) do { (void)(l); } while (0)
+#define lockdep_assert_not_held(l) do { (void)(l); } while (0)
#define lockdep_assert_held_exclusive(l) do { (void)(l); } while (0)
#define lockdep_assert_held_read(l) do { (void)(l); } while (0)
#define lockdep_assert_held_once(l) do { (void)(l); } while (0)
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 856b3d37c965..cdb82f1ce49a 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -3657,8 +3657,12 @@ int lock_is_held_type(struct lockdep_map *lock, int read)
unsigned long flags;
int ret = 0;
+ /*
+ * Avoid false negative lockdep_assert_held() and
+ * lockdep_assert_not_held().
+ */
if (unlikely(current->lockdep_recursion))
- return 1; /* avoid false negative lockdep_assert_held() */
+ return -1;
raw_local_irq_save(flags);
check_flags(flags);
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