ACPICA: Events: Always modify GPE registers under the GPE lock

It is reported that there are pieces of code invoking acpi_ev_finish_gpe()
without holding acpi_gbl_gpe_lock. Since this function will modify GPE
register values, there could be races breaking the register modification
process.

This patch fixes this issue. Lv Zheng.

Reported-by: Joe Liu <joe.liu@apple.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/evgpe.c b/drivers/acpi/acpica/evgpe.c
index 81db932b15ee..aa70154cf4fa 100644
--- a/drivers/acpi/acpica/evgpe.c
+++ b/drivers/acpi/acpica/evgpe.c
@@ -616,8 +616,11 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context)
 {
         struct acpi_gpe_event_info *gpe_event_info = context;
+        acpi_cpu_flags flags;
 
+        flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
         (void)acpi_ev_finish_gpe(gpe_event_info);
+        acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 
         ACPI_FREE(gpe_event_info);
         return;