plugin/amdgpu: validate dmabuf_fd before drmPrimeFDToHandle() call

In amdgpu_plugin_drm_restore_file(), dmabuf_fd can reach the
drmPrimeFDToHandle() call as -1 if fdstore_get() fails or if
boinfo->handle is -1 while boinfo->is_import is true. Passing
an invalid fd to libdrm causes a hard restore failure instead
of a retry. Check for -1 and set retry_needed so the restore
coordinator can retry later.

When retry_needed is set, some dmabufs entries are still invalid,
so skip record_completed_work() and restore_bo_contents_drm()
to avoid operating on incomplete state.

Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>

Author: rst0git

plugins/amdgpu/amdgpu_plugin_drm.c

@@ -538,6 +538,10 @@ int amdgpu_plugin_drm_restore_file(int fd, CriuRenderNode *rd)
 		}
 
 		if (boinfo->is_import) {
+			if (dmabuf_fd == -1) {
+				retry_needed = true;
+				continue;
+			}
 			ret = drmPrimeFDToHandle(device_fd, dmabuf_fd, &handle);
 			if (ret) {
 				pr_perror("Failed to get handle from dmabuf fd");
@@ -619,6 +623,9 @@ int amdgpu_plugin_drm_restore_file(int fd, CriuRenderNode *rd)
 		goto exit;
 	}
 
+	if (retry_needed)
+		goto exit;
+
 	ret = record_completed_work(-1, rd->drm_render_minor);
 	if (ret)
 		goto exit;