[PATCH v2] rcu: replace ________p1 and _________p1 with __UNIQUE_ID(rcu)
From: Chun-Hung Tseng
Date: Wed Sep 15 2021 - 05:03:32 EST
This commit replaced both ________p1 and _________p1 with __UNIQUE_ID(rcu).
Necessary modifications due to the changes in the RCU macros have also been
reflected in this commit.
__UNIQUE_ID(rcu) will generate unique variable names during compilation,
which eliminates the need of ________p1 and _________p1 (both having 4
occurrences prior to the code change). Also, this avoids the variable name
shadowing issue.
The same idea is used for the min/max macros (commit 589a978 and commit
e9092d0).
Signed-off-by: Jim Huang <jserv@xxxxxxxxxxxxxxxx>
Signed-off-by: Chun-Hung Tseng <henrybear327@xxxxxxxxx>
---
include/linux/rcupdate.h | 50 ++++++++++++++++++++++------------------
include/linux/srcu.h | 3 ++-
2 files changed, 30 insertions(+), 23 deletions(-)
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 434d12fe2d4f..213b7eb49974 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -363,6 +363,12 @@ static inline void rcu_preempt_sleep_check(void) { }
#define rcu_check_sparse(p, space)
#endif /* #else #ifdef __CHECKER__ */
+#define __unrcu_pointer(p, local) \
+({ \
+ typeof(*p) *local = (typeof(*p) *__force)(p); \
+ rcu_check_sparse(p, __rcu); \
+ ((typeof(*p) __force __kernel *)(local)); \
+})
/**
* unrcu_pointer - mark a pointer as not being RCU protected
* @p: pointer needing to lose its __rcu property
@@ -370,39 +376,35 @@ static inline void rcu_preempt_sleep_check(void) { }
* Converts @p from an __rcu pointer to a __kernel pointer.
* This allows an __rcu pointer to be used with xchg() and friends.
*/
-#define unrcu_pointer(p) \
-({ \
- typeof(*p) *_________p1 = (typeof(*p) *__force)(p); \
- rcu_check_sparse(p, __rcu); \
- ((typeof(*p) __force __kernel *)(_________p1)); \
-})
+#define unrcu_pointer(p) __unrcu_pointer(p, __UNIQUE_ID(rcu))
-#define __rcu_access_pointer(p, space) \
+#define __rcu_access_pointer(p, local, space) \
({ \
- typeof(*p) *_________p1 = (typeof(*p) *__force)READ_ONCE(p); \
+ typeof(*p) *local = (typeof(*p) *__force)READ_ONCE(p); \
rcu_check_sparse(p, space); \
- ((typeof(*p) __force __kernel *)(_________p1)); \
+ ((typeof(*p) __force __kernel *)(local)); \
})
-#define __rcu_dereference_check(p, c, space) \
+#define __rcu_dereference_check(p, local, c, space) \
({ \
/* Dependency order vs. p above. */ \
- typeof(*p) *________p1 = (typeof(*p) *__force)READ_ONCE(p); \
+ typeof(*p) *local = (typeof(*p) *__force)READ_ONCE(p); \
RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_check() usage"); \
rcu_check_sparse(p, space); \
- ((typeof(*p) __force __kernel *)(________p1)); \
+ ((typeof(*p) __force __kernel *)(local)); \
})
-#define __rcu_dereference_protected(p, c, space) \
+#define __rcu_dereference_protected(p, local, c, space) \
({ \
RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_protected() usage"); \
rcu_check_sparse(p, space); \
((typeof(*p) __force __kernel *)(p)); \
})
-#define rcu_dereference_raw(p) \
+#define __rcu_dereference_raw(p, local) \
({ \
/* Dependency order vs. p above. */ \
- typeof(p) ________p1 = READ_ONCE(p); \
- ((typeof(*p) __force __kernel *)(________p1)); \
+ typeof(p) local = READ_ONCE(p); \
+ ((typeof(*p) __force __kernel *)(local)); \
})
+#define rcu_dereference_raw(p) __rcu_dereference_raw(p, __UNIQUE_ID(rcu))
/**
* RCU_INITIALIZER() - statically initialize an RCU-protected global variable
@@ -489,7 +491,7 @@ do { \
* when tearing down multi-linked structures after a grace period
* has elapsed.
*/
-#define rcu_access_pointer(p) __rcu_access_pointer((p), __rcu)
+#define rcu_access_pointer(p) __rcu_access_pointer((p), __UNIQUE_ID(rcu), __rcu)
/**
* rcu_dereference_check() - rcu_dereference with debug checking
@@ -525,7 +527,8 @@ do { \
* annotated as __rcu.
*/
#define rcu_dereference_check(p, c) \
- __rcu_dereference_check((p), (c) || rcu_read_lock_held(), __rcu)
+ __rcu_dereference_check((p), __UNIQUE_ID(rcu), \
+ (c) || rcu_read_lock_held(), __rcu)
/**
* rcu_dereference_bh_check() - rcu_dereference_bh with debug checking
@@ -540,7 +543,8 @@ do { \
* rcu_read_lock() but also rcu_read_lock_bh() into account.
*/
#define rcu_dereference_bh_check(p, c) \
- __rcu_dereference_check((p), (c) || rcu_read_lock_bh_held(), __rcu)
+ __rcu_dereference_check((p), __UNIQUE_ID(rcu), \
+ (c) || rcu_read_lock_bh_held(), __rcu)
/**
* rcu_dereference_sched_check() - rcu_dereference_sched with debug checking
@@ -555,7 +559,8 @@ do { \
* only rcu_read_lock() but also rcu_read_lock_sched() into account.
*/
#define rcu_dereference_sched_check(p, c) \
- __rcu_dereference_check((p), (c) || rcu_read_lock_sched_held(), \
+ __rcu_dereference_check((p), __UNIQUE_ID(rcu), \
+ (c) || rcu_read_lock_sched_held(), \
__rcu)
/*
@@ -565,7 +570,8 @@ do { \
* The no-tracing version of rcu_dereference_raw() must not call
* rcu_read_lock_held().
*/
-#define rcu_dereference_raw_check(p) __rcu_dereference_check((p), 1, __rcu)
+#define rcu_dereference_raw_check(p) \
+ __rcu_dereference_check((p), __UNIQUE_ID(rcu), 1, __rcu)
/**
* rcu_dereference_protected() - fetch RCU pointer when updates prevented
@@ -584,7 +590,7 @@ do { \
* but very ugly failures.
*/
#define rcu_dereference_protected(p, c) \
- __rcu_dereference_protected((p), (c), __rcu)
+ __rcu_dereference_protected((p), __UNIQUE_ID(rcu), (c), __rcu)
/**
diff --git a/include/linux/srcu.h b/include/linux/srcu.h
index e6011a9975af..01226e4d960a 100644
--- a/include/linux/srcu.h
+++ b/include/linux/srcu.h
@@ -117,7 +117,8 @@ static inline int srcu_read_lock_held(const struct srcu_struct *ssp)
* lockdep_is_held() calls.
*/
#define srcu_dereference_check(p, ssp, c) \
- __rcu_dereference_check((p), (c) || srcu_read_lock_held(ssp), __rcu)
+ __rcu_dereference_check((p), __UNIQUE_ID(rcu), \
+ (c) || srcu_read_lock_held(ssp), __rcu)
/**
* srcu_dereference - fetch SRCU-protected pointer for later dereferencing
--
2.25.1