[LTP] [PATCH] android: getcwd0[12]: use temp dir from $TMPDIR if present

[Cyril Hrubis]

Hi!
> getcwd01/getcwd02 tests are broken on an Android system as the device
> doesn't have "/tmp". Instead of hardcoding the temporary directory
> to be "/tmp", look for it in 'TMPDIR' environment variable and fallback
> to "/tmp" if its not defined.
> 
> Signed-off-by: Sandeep Patil <sspatil@google.com>
> ---
>  testcases/kernel/syscalls/getcwd/getcwd01.c      |  4 ++-
>  testcases/kernel/syscalls/getcwd/getcwd02.c      |  8 +++--
>  testcases/kernel/syscalls/getcwd/getcwd_helper.h | 39 ++++++++++++++++++++++++
>  3 files changed, 47 insertions(+), 4 deletions(-)
>  create mode 100644 testcases/kernel/syscalls/getcwd/getcwd_helper.h
> 
> diff --git a/testcases/kernel/syscalls/getcwd/getcwd01.c b/testcases/kernel/syscalls/getcwd/getcwd01.c
> index fdf306103..cde4b1641 100644
> --- a/testcases/kernel/syscalls/getcwd/getcwd01.c
> +++ b/testcases/kernel/syscalls/getcwd/getcwd01.c
> @@ -34,9 +34,11 @@
>   */
>  
>  #include <errno.h>
> +#include <stdlib.h>
>  #include <unistd.h>
>  #include <limits.h>
>  #include "tst_test.h"
> +#include "getcwd_helper.h"
>  
>  static char buffer[5];
>  
> @@ -76,7 +78,7 @@ static void verify_getcwd(unsigned int n)
>  
>  static void setup(void)
>  {
> -	SAFE_CHDIR("/tmp");
> +	SAFE_CHDIR(get_tmpdir_path());
>  }

As far as I can tell we can simply remove the chdir() here. The only
part of the test that may be afected by currect directory is the ERANGE
test and even then we pass buffer size 1 there, so even if CWD was "/"
we would have to write two characters to the buffer (including the
terminating zero byte) so there is no chance that the test will fail no
matter what CWD is set to.

>  static struct tst_test test = {
> diff --git a/testcases/kernel/syscalls/getcwd/getcwd02.c b/testcases/kernel/syscalls/getcwd/getcwd02.c
> index 384157d42..11480f14f 100644
> --- a/testcases/kernel/syscalls/getcwd/getcwd02.c
> +++ b/testcases/kernel/syscalls/getcwd/getcwd02.c
> @@ -28,8 +28,8 @@
>  #include <stdlib.h>
>  #include <string.h>
>  #include "tst_test.h"
> +#include "getcwd_helper.h"
>  
> -#define TMPDIR "/tmp"
>  
>  static char exp_buf[PATH_MAX];
>  static char buffer[PATH_MAX];
> @@ -71,9 +71,11 @@ end:
>  
>  static void setup(void)
>  {
> -	SAFE_CHDIR(TMPDIR);
> +	const char *tmpdir = get_tmpdir_path();
>  
> -	if (!realpath(TMPDIR, exp_buf))
> +	SAFE_CHDIR(tmpdir);
> +
> +	if (!realpath(tmpdir, exp_buf))
>  		tst_brk(TBROK | TERRNO, "realpath() failed");
>  
>  	tst_res(TINFO, "Expected path '%s'", exp_buf);
> diff --git a/testcases/kernel/syscalls/getcwd/getcwd_helper.h b/testcases/kernel/syscalls/getcwd/getcwd_helper.h
> new file mode 100644
> index 000000000..6a78ddbf5
> --- /dev/null
> +++ b/testcases/kernel/syscalls/getcwd/getcwd_helper.h
> @@ -0,0 +1,39 @@
> +/*
> + * Copyright (c) 2017 Google Inc.
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software Foundation,
> + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
> + */
> +
> +#ifndef GETCWD_HELPER_H
> +#define GETCWD_HELPER_H
> +
> +#include <stdlib.h>
> +
> +#define GETCWD_TMPDIR_PATH	"/tmp"
> +
> +static const char *get_tmpdir_path(void)
> +{
> +	const char *tmpdir;
> +
> +	tmpdir = getenv("TMPDIR");
> +	if (!tmpdir)
> +		return GETCWD_TMPDIR_PATH;
> +
> +	/* $TMPDIR must be absolute path.. */
> +	if (tmpdir[0] != '/')
> +		return GETCWD_TMPDIR_PATH;

We may as well check that the "/tmp" exist here first, then fall back to
$TMPDIR and finally call tst_brk() if $TMPDIR does not exist or if it's
relative, which would be a bit more specific error message than
chdir("/tmp") failed with ENOENT.

> +	return tmpdir;
> +}
> +
> +#endif /* GETCWD_HELPER_H */
> -- 
> 2.14.1.342.g6490525c54-goog
> 

-- 
Cyril Hrubis
chrubis@suse.cz