Re: [PATCH] selftest: mm: Test if hugepage does not get leaked during __bio_release_pages()

[Donet Tom <donettom@linux.ibm.com>]

On 6/6/24 18:44, Pankaj Raghav wrote:
>> +void run_dio_using_hugetlb(unsigned int start_off, unsigned int end_off)
>> +{
>> +	int fd;
>> +	char *buffer =  NULL;
>> +	char *orig_buffer = NULL;
>> +	size_t h_pagesize = 0;
>> +	size_t writesize;
>> +	int free_hpage_b = 0;
>> +	int free_hpage_a = 0;
>> +
>> +	writesize = end_off - start_off;
>> +
>> +	/* Get the default huge page size */
>> +	h_pagesize = default_huge_page_size();
>> +	if (!h_pagesize)
>> +		ksft_exit_fail_msg("Unable to determine huge page size\n");
>> +
>> +	/* Open the file to DIO */
>> +	fd = open("/tmp", O_TMPFILE | O_RDWR | O_DIRECT);
> I encountered a build error as follows in NixOS:
>
> In file included from /nix/store/fwh4fxd747m0py3ib3s5abamia9nrf90-glibc-2.39-52-dev/include/fcntl.h:342,
>                   from hugetlb_dio.c:15:
> In function ‘open’,
>      inlined from ‘run_dio_using_hugetlb’ at hugetlb_dio.c:41:7:
> /nix/store/fwh4fxd747m0py3ib3s5abamia9nrf90-glibc-2.39-52-dev/include/bits/fcntl2.h:50:11: error: call to ‘__open_missing_mode’ declared with attribute error: open with O_CREAT or O_TMPFILE in second argument needs 3 arguments
>     50 |           __open_missing_mode ();
>
>
> I saw a commit that fixed similar issues with open syscall before:
> 8b65ef5ad486 ("selftests/mm: Fix build with _FORTIFY_SOURCE")
>
> So something like this should fix the issue?
>
> -       fd = open("/tmp", O_TMPFILE | O_RDWR | O_DIRECT);
> +       fd = open("/tmp", O_TMPFILE | O_RDWR | O_DIRECT, 0664);

Thank you Pankaj.

I am able to reproduce this error with "-D_FORTIFY_SOURCE=2 -O2".  I will post v3 with this fix.

-donet


>
>> +	if (fd < 0)
>> +		ksft_exit_fail_msg("Error opening file");
>> +