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Subject[PATCH] treewide: Rename rcu_dereference_raw_notrace to _check
Date
The rcu_dereference_raw_notrace() API name is confusing.
It is equivalent to rcu_dereference_raw() except that it also does
sparse pointer checking.

There are only a few users of rcu_dereference_raw_notrace(). This
patches renames all of them to be rcu_dereference_raw_check with the
"check" indicating sparse checking.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>

---
Previous discussion is here:
https://lore.kernel.org/linuxppc-dev/20190528200014.GV28207@linux.ibm.com/T/

Documentation/RCU/Design/Requirements/Requirements.html | 2 +-
arch/powerpc/include/asm/kvm_book3s_64.h | 2 +-
include/linux/rculist.h | 4 ++--
include/linux/rcupdate.h | 2 +-
kernel/trace/ftrace_internal.h | 8 ++++----
kernel/trace/trace.c | 4 ++--
6 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/Documentation/RCU/Design/Requirements/Requirements.html b/Documentation/RCU/Design/Requirements/Requirements.html
index f04c467e55c5..467251f7fef6 100644
--- a/Documentation/RCU/Design/Requirements/Requirements.html
+++ b/Documentation/RCU/Design/Requirements/Requirements.html
@@ -2514,7 +2514,7 @@ disabled across the entire RCU read-side critical section.
<p>
It is possible to use tracing on RCU code, but tracing itself
uses RCU.
-For this reason, <tt>rcu_dereference_raw_notrace()</tt>
+For this reason, <tt>rcu_dereference_raw_check()</tt>
is provided for use by tracing, which avoids the destructive
recursion that could otherwise ensue.
This API is also used by virtualization in some architectures,
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 21b1ed5df888..53388a311967 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -546,7 +546,7 @@ static inline void note_hpte_modification(struct kvm *kvm,
*/
static inline struct kvm_memslots *kvm_memslots_raw(struct kvm *kvm)
{
- return rcu_dereference_raw_notrace(kvm->memslots[0]);
+ return rcu_dereference_raw_check(kvm->memslots[0]);
}

extern void kvmppc_mmu_debugfs_init(struct kvm *kvm);
diff --git a/include/linux/rculist.h b/include/linux/rculist.h
index e91ec9ddcd30..10aab1d2d471 100644
--- a/include/linux/rculist.h
+++ b/include/linux/rculist.h
@@ -642,10 +642,10 @@ static inline void hlist_add_behind_rcu(struct hlist_node *n,
* not do any RCU debugging or tracing.
*/
#define hlist_for_each_entry_rcu_notrace(pos, head, member) \
- for (pos = hlist_entry_safe (rcu_dereference_raw_notrace(hlist_first_rcu(head)),\
+ for (pos = hlist_entry_safe (rcu_dereference_raw_check(hlist_first_rcu(head)),\
typeof(*(pos)), member); \
pos; \
- pos = hlist_entry_safe(rcu_dereference_raw_notrace(hlist_next_rcu(\
+ pos = hlist_entry_safe(rcu_dereference_raw_check(hlist_next_rcu(\
&(pos)->member)), typeof(*(pos)), member))

/**
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 0c9b92799abc..e5161e377ad4 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -478,7 +478,7 @@ do { \
* The no-tracing version of rcu_dereference_raw() must not call
* rcu_read_lock_held().
*/
-#define rcu_dereference_raw_notrace(p) __rcu_dereference_check((p), 1, __rcu)
+#define rcu_dereference_raw_check(p) __rcu_dereference_check((p), 1, __rcu)

/**
* rcu_dereference_protected() - fetch RCU pointer when updates prevented
diff --git a/kernel/trace/ftrace_internal.h b/kernel/trace/ftrace_internal.h
index 0515a2096f90..0456e0a3dab1 100644
--- a/kernel/trace/ftrace_internal.h
+++ b/kernel/trace/ftrace_internal.h
@@ -6,22 +6,22 @@

/*
* Traverse the ftrace_global_list, invoking all entries. The reason that we
- * can use rcu_dereference_raw_notrace() is that elements removed from this list
+ * can use rcu_dereference_raw_check() is that elements removed from this list
* are simply leaked, so there is no need to interact with a grace-period
- * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
+ * mechanism. The rcu_dereference_raw_check() calls are needed to handle
* concurrent insertions into the ftrace_global_list.
*
* Silly Alpha and silly pointer-speculation compiler optimizations!
*/
#define do_for_each_ftrace_op(op, list) \
- op = rcu_dereference_raw_notrace(list); \
+ op = rcu_dereference_raw_check(list); \
do

/*
* Optimized for just a single item in the list (as that is the normal case).
*/
#define while_for_each_ftrace_op(op) \
- while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
+ while (likely(op = rcu_dereference_raw_check((op)->next)) && \
unlikely((op) != &ftrace_list_end))

extern struct ftrace_ops __rcu *ftrace_ops_list;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2c92b3d9ea30..1d69110d9e5b 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2642,10 +2642,10 @@ static void ftrace_exports(struct ring_buffer_event *event)

preempt_disable_notrace();

- export = rcu_dereference_raw_notrace(ftrace_exports_list);
+ export = rcu_dereference_raw_check(ftrace_exports_list);
while (export) {
trace_process_export(export, event);
- export = rcu_dereference_raw_notrace(export->next);
+ export = rcu_dereference_raw_check(export->next);
}

preempt_enable_notrace();
--
2.22.0.410.gd8fdbe21b5-goog
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