Commit 9670d2bb9ed19e3720c58378fe3eadab1ea0c40e
2022-08-15T17:27:33
Make sure we hold the joystick lock when disconnecting a HIDAPI joystick This prevents crashes when calling SDL joystick API functions from a different thread while disconnection is happening. See https://github.com/libsdl-org/SDL/issues/6063 for a more thorough review of joystick locking.
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diff --git a/src/joystick/hidapi/SDL_hidapijoystick.c b/src/joystick/hidapi/SDL_hidapijoystick.c
index 3d596c8..132d3ea 100644
--- a/src/joystick/hidapi/SDL_hidapijoystick.c
+++ b/src/joystick/hidapi/SDL_hidapijoystick.c
@@ -522,21 +522,19 @@ void
HIDAPI_JoystickDisconnected(SDL_HIDAPI_Device *device, SDL_JoystickID joystickID)
{
int i, j;
- SDL_bool unique = HIDAPI_JoystickInstanceIsUnique(device, joystickID);
+
+ SDL_LockJoysticks();
- if (!unique) {
+ if (!HIDAPI_JoystickInstanceIsUnique(device, joystickID)) {
/* Disconnecting a child always disconnects the parent */
device = device->parent;
- unique = SDL_TRUE;
}
for (i = 0; i < device->num_joysticks; ++i) {
if (device->joysticks[i] == joystickID) {
- if (unique) {
- SDL_Joystick *joystick = SDL_JoystickFromInstanceID(joystickID);
- if (joystick) {
- HIDAPI_JoystickClose(joystick);
- }
+ SDL_Joystick *joystick = SDL_JoystickFromInstanceID(joystickID);
+ if (joystick) {
+ HIDAPI_JoystickClose(joystick);
}
HIDAPI_DelJoystickInstanceFromDevice(device, joystickID);
@@ -546,18 +544,18 @@ HIDAPI_JoystickDisconnected(SDL_HIDAPI_Device *device, SDL_JoystickID joystickID
HIDAPI_DelJoystickInstanceFromDevice(child, joystickID);
}
- if (unique) {
- --SDL_HIDAPI_numjoysticks;
+ --SDL_HIDAPI_numjoysticks;
- if (!shutting_down) {
- SDL_PrivateJoystickRemoved(joystickID);
- }
+ if (!shutting_down) {
+ SDL_PrivateJoystickRemoved(joystickID);
}
}
}
/* Rescan the device list in case device state has changed */
SDL_HIDAPI_change_count = 0;
+
+ SDL_UnlockJoysticks();
}
static int