[LTP] [PATCH 1/1] shmget03: Consider already mapped segments

[Petr Vorel <pvorel@suse.cz>]

Hi,

ok, Alexey already send [1] few weeks ago a different approach to fix this, which is
better, please ignore this.

[1] https://patchwork.ozlabs.org/project/ltp/patch/20210712075223.10682-1-aleksei.kodanev@bell-sw.com/

> This fixes running test on systems with already mapped segments.

> Test expected that no segment was already mapped, thus reached the
> maximum earlier:

> $ ipcs -m

> ------ Shared Memory Segments --------
> key        shmid      owner      perms      bytes      nattch     status
> 0x62001fae 0          root       660        4124096    1

> ./shmget03
> tst_test.c:1344: TINFO: Timeout per run is 0h 05m 00s
> shmget03.c:46: TBROK: shmget failed unexpectedly: ENOSPC (28)

> Signed-off-by: Petr Vorel <pvorel@suse.cz>
> ---
> Hi,

> I suppose we don't want to factor out the code counting lines and put it
> into safe_file_ops.c.

> Kind regards,
> Petr

>  testcases/kernel/syscalls/ipc/shmget/shmget03.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)

> diff --git a/testcases/kernel/syscalls/ipc/shmget/shmget03.c b/testcases/kernel/syscalls/ipc/shmget/shmget03.c
> index efbc465e1..57130e993 100644
> --- a/testcases/kernel/syscalls/ipc/shmget/shmget03.c
> +++ b/testcases/kernel/syscalls/ipc/shmget/shmget03.c
> @@ -14,15 +14,19 @@
>  #include <errno.h>
>  #include <sys/types.h>
>  #include <sys/ipc.h>
> +#include <stdio.h>
>  #include <stdlib.h>
>  #include <pwd.h>
>  #include <sys/shm.h>
>  #include "tst_test.h"
>  #include "tst_safe_sysv_ipc.h"
> +#include "tst_safe_stdio.h"
>  #include "libnewipc.h"

>  static int *queues;
>  static int maxshms, queue_cnt;
> +static int mapped_shms = -1;
> +static FILE *f = NULL;
>  static key_t shmkey;

>  static void verify_shmget(void)
> @@ -34,10 +38,19 @@ static void verify_shmget(void)
>  static void setup(void)
>  {
>  	int res, num;
> +	char c;

>  	shmkey = GETIPCKEY();

> +	f = SAFE_FOPEN("/proc/sysvipc/shm", "r");
> +	while ((c = fgetc(f)) != EOF) {
> +		if (c == '\n')
> +			mapped_shms++;
> +	}
> +	tst_res(TINFO, "Already mapped shared memory segments: %d", mapped_shms);
> +
>  	SAFE_FILE_SCANF("/proc/sys/kernel/shmmni", "%i", &maxshms);
> +	maxshms -= mapped_shms;

>  	queues = SAFE_MALLOC(maxshms * sizeof(int));
>  	for (num = 0; num < maxshms; num++) {
> @@ -62,6 +75,9 @@ static void cleanup(void)
>  		SAFE_SHMCTL(queues[num], IPC_RMID, NULL);

>  	free(queues);
> +
> +	if (f)
> +		SAFE_FCLOSE(f);
>  }

>  static struct tst_test test = {