stm class: Mark src::link __rcu
Source device's link is protected with srcu, mark it as such to have
proper build-time validation of accesses to this field. The update
side that's dereferencing it under an update lock also needs an
accessor to dereference this field to keep sparse happy.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index b79c42c..b6445d9 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -781,17 +781,20 @@
static void __stm_source_link_drop(struct stm_source_device *src,
struct stm_device *stm)
{
+ struct stm_device *link;
+
spin_lock(&src->link_lock);
- if (WARN_ON_ONCE(src->link != stm)) {
+ link = srcu_dereference_check(src->link, &stm_source_srcu, 1);
+ if (WARN_ON_ONCE(link != stm)) {
spin_unlock(&src->link_lock);
return;
}
- stm_output_free(src->link, &src->output);
+ stm_output_free(link, &src->output);
/* caller must hold stm::link_lock */
list_del_init(&src->link_entry);
/* matches stm_find_device() from stm_source_link_store() */
- stm_put_device(src->link);
+ stm_put_device(link);
rcu_assign_pointer(src->link, NULL);
spin_unlock(&src->link_lock);