On Monday, November 25, 2019 12:03:18 PM CET kc27041980@xxxxxxxxx wrote:
> From: KC27041980 <kc27041980@xxxxxxxxx>
>
> Move call to kref_get() to under the mutex_lock(&ec->mutex) as this
> will remove any delete race scenarios.
>
> Signed-off-by: KC27041980 <kc27041980@xxxxxxxxx>
> ---
> drivers/acpi/ec.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
> index da1e5c5..9c1bd57 100644
> --- a/drivers/acpi/ec.c
> +++ b/drivers/acpi/ec.c
> @@ -1073,8 +1073,12 @@ acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
> break;
> }
> }
> +
> + if (found)
> + acpi_ec_get_query_handler(handler);
> mutex_unlock(&ec->mutex);
> - return found ? acpi_ec_get_query_handler(handler) : NULL;
> +
> + return found ? handler : NULL;
> }
>
> static void acpi_ec_query_handler_release(struct kref *kref)
>
Well, what about the appended patch instead?
---
drivers/acpi/ec.c | 16 ++++------------
1 file changed, 4 insertions(+), 12 deletions(-)
Index: linux-pm/drivers/acpi/ec.c
===================================================================
--- linux-pm.orig/drivers/acpi/ec.c
+++ linux-pm/drivers/acpi/ec.c
@@ -1053,28 +1053,20 @@ void acpi_ec_unblock_transactions(void)
Event Management
-------------------------------------------------------------------------- */
static struct acpi_ec_query_handler *
-acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
-{
- if (handler)
- kref_get(&handler->kref);
- return handler;
-}
-
-static struct acpi_ec_query_handler *
acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
{
struct acpi_ec_query_handler *handler;
- bool found = false;
mutex_lock(&ec->mutex);
list_for_each_entry(handler, &ec->list, node) {
if (value == handler->query_bit) {
- found = true;
- break;
+ kref_get(&handler->kref);
+ mutex_unlock(&ec->mutex);
+ return handler;
}
}
mutex_unlock(&ec->mutex);
- return found ? acpi_ec_get_query_handler(handler) : NULL;
+ return NULL;
}
static void acpi_ec_query_handler_release(struct kref *kref)
