[LTP] hugetlb/hugeshmget: Add hugeshmget07 to test SHM_HUGETLB with /dev/zero read

[Cyril Hrubis]

Hi!
> >+	zero_fd = SAFE_OPEN("/dev/zero", O_RDONLY);
> >+
> >+	shmid = SAFE_SHMGET(IPC_PRIVATE, size, SHM_HUGETLB | SHM_R | SHM_W);
> >+
> >+	shmaddr = SAFE_SHMAT(shmid, 0, SHM_RND);
> >+	tst_res(TINFO, "shmaddr: %p", shmaddr);
> >+
> >+	for (i = 0; i < size; i += hpage_size) {
> >+		TST_EXP_VAL(read(zero_fd, shmaddr + i, hpage_size),
> >+			(ssize_t)hpage_size);
> >+	}
> >+
> >+	SAFE_CLOSE(zero_fd);
> 
> File descriptors must be initialized to -1 and closed in cleanup() with an
> fd != -1 guard. If SAFE_SHMGET() or SAFE_SHMAT() aborts, zero_fd is not
> closed. Define static int zero_fd = -1 at file scope, open it in setup(),
> and close it in cleanup().
> 
> >+	SAFE_SHMCTL(shmid, IPC_RMID, NULL);
> >+	shmid = -1;
> 
> SAFE_SHMCTL() sets shmid to -1 when called with IPC_RMID. The subsequent
> shmid = -1 assignment is redundant.

These two are valid, the rest of the code looks good.

-- 
Cyril Hrubis
chrubis@suse.cz