Re: [PATCH 1/6] selftests/liveupdate: add framework for memfd tests

[Pratyush Yadav <pratyush@kernel.org>]

On Tue, Mar 10 2026, Usama Arif wrote:

> On Mon,  9 Mar 2026 11:54:34 +0000 Pratyush Yadav <pratyush@kernel.org> wrote:
[...]
>> diff --git a/tools/testing/selftests/liveupdate/luo_memfd.c b/tools/testing/selftests/liveupdate/luo_memfd.c
>> new file mode 100644
>> index 000000000000..b779eee18387
>> --- /dev/null
>> +++ b/tools/testing/selftests/liveupdate/luo_memfd.c
>> @@ -0,0 +1,77 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +
>> +/*
>> + * Copyright (c) 2026, Google LLC.
>> + * Pratyush Yadav (Google) <pratyush@kernel.org>
>> + */
>> +
>> +/*
>> + * Selftests for memfd preservation via LUO.
>> + */
>> +
>> +#include <errno.h>
>> +#include <fcntl.h>
>> +#include <string.h>
>> +#include <sys/ioctl.h>
>> +#include <unistd.h>
>> +
>> +#include <linux/liveupdate.h>
>> +
>> +#include "../kselftest.h"
>> +#include "../kselftest_harness.h"
>> +
>> +#include "luo_test_utils.h"
>> +
>> +#define STATE_SESSION_NAME "luo-state"
>> +#define STATE_MEMFD_TOKEN 1
>> +
>> +#define LIVEUPDATE_DEV "/dev/liveupdate"
>
> Hello!
>
> LIVEUPDATE_DEV doesn't seem to be used anywhere?

Right. This is a leftover from development. Will drop.

>
>> +static int luo_fd = -1, stage;
>> +
>> +int main(int argc, char *argv[])
>> +{
>> +	int session, expected_stage = 0;
>> +
>> +	/*
>> +	 * The test takes an optional --stage argument. This lets callers
>> +	 * provide the expected stage, and if that doesn't match the test errors
>> +	 * out.
>> +	 *
>> +	 * Look for the stage. Since test_harness_run() doesn't recognize it,
>> +	 * once found, remove it from argv.
>> +	 */
>> +	for (int i = 1; i < argc; i++) {
>> +		if (strcmp(argv[i], "--stage") == 0) {
>> +			if (i + 1 < argc) {
>> +				expected_stage = atoi(argv[i + 1]);
>> +				memmove(&argv[i], &argv[i + 2], (argc - i - 1) * sizeof(char *));
>> +				argc -= 2;
>> +				i--;
>> +			} else {
>> +				ksft_exit_fail_msg("Option --stage requires an argument\n");
>> +			}
>> +		}
>> +	}
>> +
>> +	luo_fd = luo_open_device();
>> +	if (luo_fd < 0)
>> +		ksft_exit_skip("Failed to open %s (%s). Is the luo module loaded?\n",
>> +			       strerror(errno), LUO_DEVICE);
>
> Need to reverse strerror(errno) and LUO_DEVICE?

Will fix. Thanks.

>
>> +
>> +	session = luo_retrieve_session(luo_fd, STATE_SESSION_NAME);
>> +	if (session == -ENOENT)
>> +		stage = 1;
>> +	else if (session >= 0)
>> +		stage = 2;
>> +	else
>> +		fail_exit("Failed to check for state session");
>> +
>> +	if (expected_stage && expected_stage != stage)
>> +		ksft_exit_fail_msg("Stage mismatch: expected %d, got %d\n",
>> +				   expected_stage, stage);
>> +
>> +	if (stage == 1)
>> +		create_state_file(luo_fd, STATE_SESSION_NAME, STATE_MEMFD_TOKEN, 2);
>> +
>> +	test_harness_run(argc, argv);
>> +}
>> -- 
>> 2.53.0.473.g4a7958ca14-goog
>> 
>> 

-- 
Regards,
Pratyush Yadav