Re: [LTP] [PATCH v5] statvfs01: Convert to new LTP API

[Richard Palethorpe <rpalethorpe@suse.de>]

Hello,

Petr Vorel <pvorel@suse.cz> writes:

> Hi Avinesh, Richie,
>
> Generally LGTM, thanks for fixing exfat and vfat.
>
>> > +	toolong_fname = SAFE_MALLOC(buf.f_namemax + 1);
> However, length could be smaller:
> Instead using buf.f_namemax + 1 (1531) also for exfat and vfat,
> invalid length is already buf.f_namemax / NLS_MAX_CHARSET_SIZE + 1
> (256).
>
>> > +	if (fs_type == TST_VFAT_MAGIC || fs_type == TST_EXFAT_MAGIC)
>> > +		valid_fname = SAFE_MALLOC(buf.f_namemax / NLS_MAX_CHARSET_SIZE - 1);
>> > +	else
>> > +		valid_fname = SAFE_MALLOC(buf.f_namemax - 1);

There is also a memory leak when running with -I. You could just use an
4Kb (PATH_MAX) static buffer as the name. If we find an FS that allows
longer names then we can increase it.

We could also use a guarded buffer (specified in tst_test).

>
>> > -		if (TEST_RETURN == -1) {
>> > -			tst_resm(TFAIL | TTERRNO, "statvfs(%s, ...) failed",
>> > -				 TEST_PATH);
>> > -		} else {
>> > -			tst_resm(TPASS, "statvfs(%s, ...) passed", TEST_PATH);
>> > -		}
>> > +	memset(toolong_fname, 'b', buf.f_namemax + 1);
>> > +	if (fs_type == TST_VFAT_MAGIC || fs_type == TST_EXFAT_MAGIC)
>> > +		memset(valid_fname, 'a', buf.f_namemax / NLS_MAX_CHARSET_SIZE - 1);
>> > +	else
>> > +		memset(valid_fname, 'a', buf.f_namemax - 1);
> Also valid length is for buf.f_namemax, not buf.f_namemax - 1. I guess -1 is for
> \0 (NULL terminator), but tests work even with just buf.f_namemax.
>
> Also adding variable to hold the length makes source more readable.
> How about this?
>
> 	struct statvfs buf;
> 	char *valid_fname, *toolong_fname;
> 	long fs_type;
> 	long valid_len;
>
> 	fs_type = tst_fs_type(TEST_PATH);
>
> 	TST_EXP_PASS(statvfs(TEST_PATH, &buf));
>
> 	valid_len = buf.f_namemax;
> 	if (fs_type == TST_VFAT_MAGIC || fs_type == TST_EXFAT_MAGIC)
> 		valid_len = buf.f_namemax / NLS_MAX_CHARSET_SIZE;
>
> 	valid_fname = SAFE_MALLOC(valid_len);
> 	memset(valid_fname, 'a', valid_len);
>
> 	toolong_fname = SAFE_MALLOC(valid_len + 1);
> 	memset(toolong_fname, 'b', valid_len + 1);
>
> Final diff is below.
>
> Kind regards,
> Petr
>
> diff --git testcases/kernel/syscalls/statvfs/statvfs01.c testcases/kernel/syscalls/statvfs/statvfs01.c
> index 034835da7d..f357855eb1 100644
> --- testcases/kernel/syscalls/statvfs/statvfs01.c
> +++ testcases/kernel/syscalls/statvfs/statvfs01.c
> @@ -25,22 +25,21 @@ static void run(void)
>  	struct statvfs buf;
>  	char *valid_fname, *toolong_fname;
>  	long fs_type;
> +	long valid_len;
>  
>  	fs_type = tst_fs_type(TEST_PATH);
>  
>  	TST_EXP_PASS(statvfs(TEST_PATH, &buf));
>  
> -	toolong_fname = SAFE_MALLOC(buf.f_namemax + 1);
> +	valid_len = buf.f_namemax;
>  	if (fs_type == TST_VFAT_MAGIC || fs_type == TST_EXFAT_MAGIC)
> -		valid_fname = SAFE_MALLOC(buf.f_namemax / NLS_MAX_CHARSET_SIZE - 1);
> -	else
> -		valid_fname = SAFE_MALLOC(buf.f_namemax - 1);
> +		valid_len = buf.f_namemax / NLS_MAX_CHARSET_SIZE;
>  
> -	memset(toolong_fname, 'b', buf.f_namemax + 1);
> -	if (fs_type == TST_VFAT_MAGIC || fs_type == TST_EXFAT_MAGIC)
> -		memset(valid_fname, 'a', buf.f_namemax / NLS_MAX_CHARSET_SIZE - 1);
> -	else
> -		memset(valid_fname, 'a', buf.f_namemax - 1);
> +	valid_fname = SAFE_MALLOC(valid_len);
> +	memset(valid_fname, 'a', valid_len);
> +
> +	toolong_fname = SAFE_MALLOC(valid_len + 1);
> +	memset(toolong_fname, 'b', valid_len + 1);
>  
>  	TST_EXP_FD(creat(valid_fname, 0444));
>  	SAFE_CLOSE(TST_RET);


-- 
Thank you,
Richard.

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