On Sat, Jan 04, 2020 at 08:12:15PM +0530, madhuparnabhowmik04@xxxxxxxxx wrote:
> 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>
Reviewed-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
thanks,
- Joel
> ---
> 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
>
