Bugfix: bfg_claim_any: Use a mutex to avoid races around device claims

lowlevel.c

@@ -206,11 +206,14 @@ struct _device_claim {
 struct device_drv *bfg_claim_any(struct device_drv * const api, const char *verbose, const char * const devpath)
 {
 	static struct _device_claim *claims = NULL;
+	static pthread_mutex_t claims_lock = PTHREAD_MUTEX_INITIALIZER;
 	struct _device_claim *c;
 	
+	mutex_lock(&claims_lock);
 	HASH_FIND_STR(claims, devpath, c);
 	if (c)
 	{
+		mutex_unlock(&claims_lock);
 		if (verbose && opt_debug)
 		{
 			char logbuf[LOGBUFSIZ];
@@ -231,12 +234,16 @@ struct device_drv *bfg_claim_any(struct device_drv * const api, const char *verb
 	}
 	
 	if (!api)
+	{
+		mutex_unlock(&claims_lock);
 		return NULL;
+	}
 	
 	c = malloc(sizeof(*c));
 	c->devpath = strdup(devpath);
 	c->drv = api;
 	HASH_ADD_KEYPTR(hh, claims, c->devpath, strlen(devpath), c);
+	mutex_unlock(&claims_lock);
 	return NULL;
 }