[PATCH] drivers: firewire: core-transaction: Pass lockdep condition to address_handler_list iterator

From: madhuparnabhowmik04
Date: Sat Jan 04 2020 - 09:43:07 EST


From: Madhuparna Bhowmik <madhuparnabhowmik04@xxxxxxxxx>

The address_handler_list is traversed with list_for_each_entry_rcu
with address_handler_list_lock held.
list_for_each_entry_rcu has built-in RCU and lock checking.
Use it for address_handler_list traversal.

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik04@xxxxxxxxx>
---
drivers/firewire/core-transaction.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index 404a035f104d..a15e70027932 100644
--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -61,6 +61,11 @@
#define PHY_CONFIG_ROOT_ID(node_id) ((((node_id) & 0x3f) << 24) | (1 << 23))
#define PHY_IDENTIFIER(id) ((id) << 30)

+static DEFINE_SPINLOCK(address_handler_list_lock);
+static LIST_HEAD(address_handler_list);
+
+#define address_handler_list_lock_held() lock_is_held(&(address_handler_list_lock).dep_map)
+
/* returns 0 if the split timeout handler is already running */
static int try_cancel_split_timeout(struct fw_transaction *t)
{
@@ -485,7 +490,7 @@ static struct fw_address_handler *lookup_overlapping_address_handler(
{
struct fw_address_handler *handler;

- list_for_each_entry_rcu(handler, list, link) {
+ list_for_each_entry_rcu(handler, list, link, address_handler_list_lock_held()) {
if (handler->offset < offset + length &&
offset < handler->offset + handler->length)
return handler;
@@ -514,8 +519,6 @@ static struct fw_address_handler *lookup_enclosing_address_handler(
return NULL;
}

-static DEFINE_SPINLOCK(address_handler_list_lock);
-static LIST_HEAD(address_handler_list);

const struct fw_address_region fw_high_memory_region =
{ .start = FW_MAX_PHYSICAL_RANGE, .end = 0xffffe0000000ULL, };
--
2.17.1