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authorJason Gunthorpe <jgg@nvidia.com>2023-04-04 11:03:24 -0300
committerJason Gunthorpe <jgg@nvidia.com>2023-04-04 11:04:30 -0300
commit692d42d411b7db6a76382537fccbee3a12a2bcdb (patch)
tree24770529cf173188bc5d2d0d9331c0ac723b631e /include/linux/tracepoint.h
parentc52159b5be7894540acdc7a35791c0b57097fa4c (diff)
parent13a0d1ae7ee6b438f5537711a8c60cba00554943 (diff)
Merge branch 'iommufd/for-rc' into for-next
The following selftest patch requires both the bug fixes and the improvements of the selftest framework. * iommufd/for-rc: iommufd: Do not corrupt the pfn list when doing batch carry iommufd: Fix unpinning of pages when an access is present iommufd: Check for uptr overflow Linux 6.3-rc5 Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'include/linux/tracepoint.h')
-rw-r--r--include/linux/tracepoint.h15
1 files changed, 6 insertions, 9 deletions
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index e299f29375bb..6811e43c1b5c 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -242,12 +242,11 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
* not add unwanted padding between the beginning of the section and the
* structure. Force alignment to the same alignment as the section start.
*
- * When lockdep is enabled, we make sure to always do the RCU portions of
- * the tracepoint code, regardless of whether tracing is on. However,
- * don't check if the condition is false, due to interaction with idle
- * instrumentation. This lets us find RCU issues triggered with tracepoints
- * even when this tracepoint is off. This code has no purpose other than
- * poking RCU a bit.
+ * When lockdep is enabled, we make sure to always test if RCU is
+ * "watching" regardless if the tracepoint is enabled or not. Tracepoints
+ * require RCU to be active, and it should always warn at the tracepoint
+ * site if it is not watching, as it will need to be active when the
+ * tracepoint is enabled.
*/
#define __DECLARE_TRACE(name, proto, args, cond, data_proto) \
extern int __traceiter_##name(data_proto); \
@@ -260,9 +259,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
TP_ARGS(args), \
TP_CONDITION(cond), 0); \
if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) { \
- rcu_read_lock_sched_notrace(); \
- rcu_dereference_sched(__tracepoint_##name.funcs);\
- rcu_read_unlock_sched_notrace(); \
+ WARN_ON_ONCE(!rcu_is_watching()); \
} \
} \
__DECLARE_TRACE_RCU(name, PARAMS(proto), PARAMS(args), \