[LTP] [PATCH v1] Add readlink04 test

[Cyril Hrubis]

On Thu, Jan 18, 2024 at 04:07:42PM +0100, Andrea Cervesato wrote:
> From: Andrea Cervesato <andrea.cervesato@suse.com>
> 
> This test has been extracted from symlink01 and it verifies that
> readlink() is working correctly on symlink() generated files.
> 
> Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
> ---
>  runtest/syscalls                              |  2 +-
>  testcases/kernel/syscalls/readlink/.gitignore |  1 +
>  .../kernel/syscalls/readlink/readlink04.c     | 57 +++++++++++++++++++
>  3 files changed, 59 insertions(+), 1 deletion(-)
>  create mode 100644 testcases/kernel/syscalls/readlink/readlink04.c
> 
> diff --git a/runtest/syscalls b/runtest/syscalls
> index 6e2407879..339697533 100644
> --- a/runtest/syscalls
> +++ b/runtest/syscalls
> @@ -1125,9 +1125,9 @@ readahead02 readahead02
>  readdir01 readdir01
>  readdir21 readdir21
>  
> -readlink01A symlink01 -T readlink01
>  readlink01 readlink01
>  readlink03 readlink03
> +readlink04 readlink04
>  
>  #readlinkat test cases
>  readlinkat01 readlinkat01
> diff --git a/testcases/kernel/syscalls/readlink/.gitignore b/testcases/kernel/syscalls/readlink/.gitignore
> index 307817f4d..53e65eb5b 100644
> --- a/testcases/kernel/syscalls/readlink/.gitignore
> +++ b/testcases/kernel/syscalls/readlink/.gitignore
> @@ -1,2 +1,3 @@
>  /readlink01
>  /readlink03
> +/readlink04
> diff --git a/testcases/kernel/syscalls/readlink/readlink04.c b/testcases/kernel/syscalls/readlink/readlink04.c
> new file mode 100644
> index 000000000..8d7d038bb
> --- /dev/null
> +++ b/testcases/kernel/syscalls/readlink/readlink04.c
> @@ -0,0 +1,57 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
> + *    Author: David Fenner
> + *    Copilot: Jon Hendrickson
> + * Copyright (C) 2024 Andrea Cervesato <andrea.cervesato@suse.com>
> + */
> +
> +/*\
> + * [Description]
> + *
> + * This test verifies that readlink() is working correctly on symlink()
> + * generated files.
> + */
> +
> +#include "tst_test.h"
> +
> +static void test_readlink(void)
> +{
> +	char *symname = "my_symlink0";
> +
> +	SAFE_SYMLINK(tst_get_tmpdir(), symname);
> +
> +	char path[PATH_MAX];
> +	struct stat path_link;
> +
> +	SAFE_READLINK(symname, path, PATH_MAX);
> +	TST_EXP_PASS(lstat(path, &path_link));
> +
> +	SAFE_UNLINK(symname);
> +}

Isn't this already tested in readlink01?

And actually the readlink01 is doing this better by comparing the string
returned from readlink() against the one we passed to the sysmlink()
syscall previously. The lastat() check is indirectly asserting that we
got right value as well, however simple memcmp() is better.

> +static void test_readlink_no_path(void)
> +{
> +	char *symname = "my_symlink1";
> +
> +	SAFE_SYMLINK("bc+eFhi!k", symname);
> +
> +	char path[PATH_MAX];
> +	struct stat path_link;
> +
> +	SAFE_READLINK(symname, path, PATH_MAX);
> +	TST_EXP_FAIL(lstat(path, &path_link), ENOENT);
> +
> +	SAFE_UNLINK(symname);
> +}

Maybe it would be easier to add this to symlink01 as well?

In reality it probably does not make much difference if we readlink a
symlink to an existing or non-existing file though...

-- 
Cyril Hrubis
chrubis@suse.cz