Handle all drmMode* errors

And remove extraneous checks for zero object IDs. See [1].

[1]: https://github.com/ascent12/drm_info/pull/46#discussion_r365556824

1 files changed, 14 insertions, 6 deletions

diff --git a/json.c b/json.c
index 9c85ecc..fac7025 100644
--- a/json.c
+++ b/json.c
@@ -183,6 +183,10 @@ static struct json_object *in_formats_info(int fd, uint32_t blob_id)
 	struct json_object *arr = json_object_new_array();
 
 	drmModePropertyBlobRes *blob = drmModeGetPropertyBlob(fd, blob_id);
+	if (!blob) {
+		perror("drmModeGetPropertyBlob");
+		return NULL;
+	}
 
 	struct drm_format_modifier_blob *data = blob->data;
 
@@ -243,12 +247,12 @@ static struct json_object *mode_info(const drmModeModeInfo *mode)
 
 static struct json_object *mode_id_info(int fd, uint32_t blob_id)
 {
-	if (blob_id == 0) {
+	drmModePropertyBlobRes *blob = drmModeGetPropertyBlob(fd, blob_id);
+	if (!blob) {
+		perror("drmModeGetPropertyBlob");
 		return NULL;
 	}
 
-	drmModePropertyBlobRes *blob = drmModeGetPropertyBlob(fd, blob_id);
-
 	drmModeModeInfo *mode = blob->data;
 
 	struct json_object *obj = mode_info(mode);
@@ -263,6 +267,10 @@ static struct json_object *writeback_pixel_formats_info(int fd, uint32_t blob_id
 	struct json_object *arr = json_object_new_array();
 
 	drmModePropertyBlobRes *blob = drmModeGetPropertyBlob(fd, blob_id);
+	if (!blob) {
+		perror("drmModeGetPropertyBlob");
+		return NULL;
+	}
 
 	uint32_t *fmts = blob->data;
 	uint32_t fmts_len = blob->length / sizeof(uint32_t);
@@ -277,12 +285,12 @@ static struct json_object *writeback_pixel_formats_info(int fd, uint32_t blob_id
 
 static struct json_object *path_info(int fd, uint32_t blob_id)
 {
-	if (blob_id == 0) {
+	drmModePropertyBlobRes *blob = drmModeGetPropertyBlob(fd, blob_id);
+	if (!blob) {
+		perror("drmModeGetPropertyBlob");
 		return NULL;
 	}
 
-	drmModePropertyBlobRes *blob = drmModeGetPropertyBlob(fd, blob_id);
-
 	struct json_object *obj = json_object_new_string_len(blob->data, blob->length);
 
 	drmModeFreePropertyBlob(blob);