static code checking with coccinelle was unhappy with:
./kernel/locking/percpu-rwsem.c:113 WARNING: return of wrong type
int != unsigned int
current state:
include/linux/percpu-rwsem.h:
struct percpu_rw_semaphore {
unsigned int __percpu *fast_read_ctr;
...
atomic_t slow_read_ctr;
allocated as int:
int __percpu_init_rwsem(struct percpu_rw_semaphore *brw,
const char *name, struct lock_class_key *rwsem_key)
{
brw->fast_read_ctr = alloc_percpu(int);
used compliant with type int in:
static bool update_fast_ctr(struct percpu_rw_semaphore *brw,
unsigned int val)
usage (2):
update_fast_ctr(brw, +1)
update_fast_ctr(brw, -1)
so val should be int here not unsigned int
static int clear_fast_ctr(struct percpu_rw_semaphore *brw)
usage (1):
atomic_add(clear_fast_ctr(brw), &brw->slow_read_ctr);
slow_read_ctr is atomic_t which is int so it would be consistent here to
have fast_read_ctr being changed to int as well.
This patch changes:
fast_read_ctr to int
clear_fast_ctr():sum to int
update_fast_ctr():val to int
to make usage of fast_read_ctr consistent with respect to type.
( Patch was build tested with x86_64_defconfig +
CONFIG_UPROBE_EVENT (implies CONFIG_PERCPU_RWSEM=y))
Signed-off-by: Nicholas Mc Guire <hof...@osadl.org>
---
include/linux/percpu-rwsem.h | 2 +-
kernel/locking/percpu-rwsem.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h
index 3e88c9a..ba37dbe 100644
--- a/include/linux/percpu-rwsem.h
+++ b/include/linux/percpu-rwsem.h
@@ -8,7 +8,7 @@
#include <linux/lockdep.h>
struct percpu_rw_semaphore {
- unsigned int __percpu *fast_read_ctr;
+ int __percpu *fast_read_ctr;
atomic_t write_ctr;
struct rw_semaphore rw_sem;
atomic_t slow_read_ctr;
diff --git a/kernel/locking/percpu-rwsem.c b/kernel/locking/percpu-rwsem.c
index 652a8ee..002837d 100644
--- a/kernel/locking/percpu-rwsem.c
+++ b/kernel/locking/percpu-rwsem.c
@@ -52,7 +52,7 @@ void percpu_free_rwsem(struct percpu_rw_semaphore *brw)
* reader inside the critical section. See the comments in down_write and
* up_write below.
*/
-static bool update_fast_ctr(struct percpu_rw_semaphore *brw, unsigned int val)
+static bool update_fast_ctr(struct percpu_rw_semaphore *brw, int val)
{
bool success = false;
@@ -102,7 +102,7 @@ void percpu_up_read(struct percpu_rw_semaphore *brw)
static int clear_fast_ctr(struct percpu_rw_semaphore *brw)
{
- unsigned int sum = 0;
+ int sum = 0;
int cpu;
for_each_possible_cpu(cpu) {
--
1.7.10.4
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