| Message ID | 1574679798-18958-1-git-send-email-KC17041980@gmail.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | [1/1] acpi/ec.c: Move call to kref_get() to under the mutex_lock(&ec->mutex) | expand |
On Monday, November 25, 2019 12:03:18 PM CET kc27041980@gmail.com wrote: > From: KC27041980 <kc27041980@gmail.com> > > 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@gmail.com> > --- > 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)
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)