[LTP] [PATCH] getrandom: Add negative tests for getrandom

[Avinesh Kumar]

Hi Yang Xu,
Please see comments below

On Tuesday, April 16, 2024 10:04:48 AM GMT+2 Yang Xu via ltp wrote:
> Add negative cases for getrandom(), when errno is EFAULT or EINVAL
> 
> Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
> ---
>  runtest/syscalls                              |  1 +
>  .../kernel/syscalls/getrandom/.gitignore      |  1 +
>  .../kernel/syscalls/getrandom/getrandom05.c   | 46 +++++++++++++++++++
>  3 files changed, 48 insertions(+)
>  create mode 100644 testcases/kernel/syscalls/getrandom/getrandom05.c
> 
> diff --git a/runtest/syscalls b/runtest/syscalls
> index cc1e39c05..62eb4c1cd 100644
> --- a/runtest/syscalls
> +++ b/runtest/syscalls
> @@ -504,6 +504,7 @@ getrandom01 getrandom01
>  getrandom02 getrandom02
>  getrandom03 getrandom03
>  getrandom04 getrandom04
> +getrandom05 getrandom05
> 
>  getresgid01 getresgid01
>  getresgid01_16 getresgid01_16
> diff --git a/testcases/kernel/syscalls/getrandom/.gitignore
> b/testcases/kernel/syscalls/getrandom/.gitignore index ef06ece9d..e47d8b3f4
> 100644
> --- a/testcases/kernel/syscalls/getrandom/.gitignore
> +++ b/testcases/kernel/syscalls/getrandom/.gitignore
> @@ -2,3 +2,4 @@
>  /getrandom02
>  /getrandom03
>  /getrandom04
> +/getrandom05
> diff --git a/testcases/kernel/syscalls/getrandom/getrandom05.c
> b/testcases/kernel/syscalls/getrandom/getrandom05.c new file mode 100644
> index 000000000..a50228d3d
> --- /dev/null
> +++ b/testcases/kernel/syscalls/getrandom/getrandom05.c
> @@ -0,0 +1,46 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2024 FUJITSU LIMITED. All Rights Reserved.
> + * Author: Yang Xu <xuyang2018.jy@fujitsu.com>
> + */
> +
> +/*\
> + * [Description]
> + *
> + * Verify that getrandom(2) fails with
> + *
> + * - EFAULT when buf address is outside the accessible address space
> + * - EINVAL when flag is invalid
> + */
> +
> +#include <sys/random.h>
> +#include "tst_test.h"
> +
> +static char buff_efault[64];
> +static char buff_einval[64];
> +
> +static struct test_case_t {
> +	char *buff;
> +	size_t size;
> +	unsigned int flag;
> +	int expected_errno;
> +	char *desc;
> +} tcases[] = {
> +	{NULL, sizeof(buff_efault), 0, EFAULT,
We usually use '(void *) -1' for inaccessible address.
> +		"buf address is outside the accessible address space"},
> +	{buff_einval, sizeof(buff_einval), -1, EINVAL, "flag is invalid"},
> +};
> +
> +static void verify_getrandom(unsigned int i)
> +{
> +	struct test_case_t *tc = &tcases[i];
> +
> +	TST_EXP_FAIL(getrandom(tc->buff, tc->size, tc->flag),
should be TST_EXP_FAIL2() here as getrandom() returns number of bytes copied
to buf (i.e. a non-negative integer) on success.
> +		tc->expected_errno, "%s", tc->desc);
> +}
> +
> +static struct tst_test test = {
> +	.tcnt = ARRAY_SIZE(tcases),
> +	.test = verify_getrandom,
> +	.needs_root = 1,
Do we really need root for this?
> +};

Regards,
Avinesh