The .prev member of a rculist should not be used directly by users
because it's not rcu-safe. A convenient fake mutex (rculist_fake_mutex)
helps ensuring that in conjunction with clang's thread safety
extensions.

Only writers with exclusive access to the rculist should access .prev
via some of the provided *_protected() accessors.

Use rculist_back_protected() in REVERSE_PROTECTED iterators to avoid
clang's compilation warning.

Signed-off-by: Adrian Moreno <[email protected]>
---
 lib/rculist.h | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/rculist.h b/lib/rculist.h
index 9bb8cbf3e..6df963eb2 100644
--- a/lib/rculist.h
+++ b/lib/rculist.h
@@ -378,12 +378,14 @@ rculist_is_singleton_protected(const struct rculist *list)
          UPDATE_MULTIVAR(ITER, rculist_next(ITER_VAR(ITER))))
 
 #define RCULIST_FOR_EACH_REVERSE_PROTECTED(ITER, MEMBER, RCULIST)             \
-    for (INIT_MULTIVAR(ITER, MEMBER, (RCULIST)->prev, struct rculist);        \
+    for (INIT_MULTIVAR(ITER, MEMBER, rculist_back_protected(RCULIST),         \
+                       struct rculist);                                       \
          CONDITION_MULTIVAR(ITER, MEMBER, ITER_VAR(ITER) != (RCULIST));       \
-         UPDATE_MULTIVAR(ITER, ITER_VAR(ITER)->prev))
+         UPDATE_MULTIVAR(ITER, rculist_back_protected(ITER_VAR(ITER))))
 
 #define RCULIST_FOR_EACH_REVERSE_PROTECTED_CONTINUE(ITER, MEMBER, RCULIST)    \
-    for (INIT_MULTIVAR(ITER, MEMBER, (ITER)->MEMBER.prev, struct rculist);    \
+    for (INIT_MULTIVAR(ITER, MEMBER, rculist_back_protected(ITER->MEMBER),    \
+                       struct rculist);                                       \
          CONDITION_MULTIVAR(ITER, MEMBER, ITER_VAR(ITER) != (RCULIST));       \
          UPDATE_MULTIVAR(ITER, ITER_VAR(ITER)->prev))
 
-- 
2.38.1

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