Even if a vgem device is configured in, we will skip the import_vgem_fd() test almost every time. TAP version 13 1..11 # Testing heap: system # ======================================= # Testing allocation and importing: ok 1 # SKIP Could not open vgem -1 The problem is that we use the DRM_IOCTL_VERSION ioctl to query the driver version information but leave the name field a non-null-terminated string. Terminate it properly to actually test against the vgem device. While at it, let's check the length of the driver name is exactly 4 bytes and return early otherwise (in case there is a name like "vgemfoo" that gets converted to "vgem\0" unexpectedly). Signed-off-by: Zenghui Yu <yuzenghui@xxxxxxxxxx> --- * From v1 [1]: - Check version.name_len is exactly 4 bytes and return early otherwise [1] https://lore.kernel.org/r/20240708134654.1725-1-yuzenghui@xxxxxxxxxx P.S., Maybe worth including the kselftests file into "DMA-BUF HEAPS FRAMEWORK" MAINTAINERS entry? tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c b/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c index 5f541522364f..5d0a809dc2df 100644 --- a/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c +++ b/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c @@ -29,9 +29,11 @@ static int check_vgem(int fd) version.name = name; ret = ioctl(fd, DRM_IOCTL_VERSION, &version); - if (ret) + if (ret || version.name_len != 4) return 0; + name[4] = '\0'; + return !strcmp(name, "vgem"); } -- 2.33.0