[LTP] [PATCH] lack of ENAMETOOLONG testcases for pathnames longer than PATH_MAX

[Cyril Hrubis]

Hi!
> 	There are different causes of ENAMETOOLONG.  It might come from
> filesystem rejecting an excessively long pathname component, but there's
> also "pathname is longer than PATH_MAX bytes, including terminating NUL"
> and that doesn't get checked anywhere.

We do have a couple of tests that checks that names over PATH_MAX are
rejected, there is no reason to add these kind of tests, however I do
not think that we tests that check that names that are just under the
limit work fine, that needs to be added.

> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> ---
> diff --git a/testcases/kernel/syscalls/chdir/chdir04.c b/testcases/kernel/syscalls/chdir/chdir04.c
> index 6e53b7fef..e8dd5121d 100644
> --- a/testcases/kernel/syscalls/chdir/chdir04.c
> +++ b/testcases/kernel/syscalls/chdir/chdir04.c
> @@ -11,6 +11,8 @@
>  #include "tst_test.h"
>  
>  static char long_dir[] = "abcdefghijklmnopqrstmnopqrstuvwxyzabcdefghijklmnopqrstmnopqrstuvwxyzabcdefghijklmnopqrstmnopqrstuvwxyzabcdefghijklmnopqrstmnopqrstuvwxyzabcdefghijklmnopqrstmnopqrstuvwxyzabcdefghijklmnopqrstmnopqrstuvwxyzabcdefghijklmnopqrstmnopqrstuvwxyzabcdefghijklmnopqrstmnopqrstuvwxyz";
> +static char long_path[PATH_MAX+1];
> +static char shorter_path[PATH_MAX];
>  static char noexist_dir[] = "noexistdir";
>  
>  static struct tcase {
> @@ -20,16 +22,23 @@ static struct tcase {
>  	{long_dir, ENAMETOOLONG},
>  	{noexist_dir, ENOENT},
>  	{0, EFAULT}, // bad_addr
> +	{long_path, ENAMETOOLONG},

This test already exists in the form of long_dir just three lines above.

> +	{shorter_path, 0},

What about we add a separate test (chdir02.c) for paths that shouldn't
be rejected. Something as:

char path[PATH_MAX];
int i;

...
	for (i = 1; i < PATH_MAX; i++) {
		memset(path, 0, sizeof(path));
		memset(path, '/', i);
		TST_EXP_PASS(chdir(path), "chdir() len=%i", i);
	}
...


That would make sure that all lenghts of paths that are valid are
accepted.

-- 
Cyril Hrubis
chrubis@suse.cz