From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cyril Hrubis <chrubis@suse.cz>
Date: Mon, 29 May 2017 16:57:09 +0200
Subject: [LTP] [PATCH 3/3] syscalls/shmat03.c: add new regression test
In-Reply-To: <1492164917-9329-3-git-send-email-yangx.jy@cn.fujitsu.com>
References: <1492164917-9329-1-git-send-email-yangx.jy@cn.fujitsu.com>
 <1492164917-9329-3-git-send-email-yangx.jy@cn.fujitsu.com>
Message-ID: <20170529145709.GC6618@rei.lan>
List-Id: <ltp.lists.linux.it>
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To: ltp@lists.linux.it

Hi!
> +	addr = shmat(shm_id, LOCATION, SHM_RND);
> +	if (addr != (void *)-1)
> +		tst_res(TINFO, "shmat() attached a nil-page unexpectedly");
> +	else
> +		tst_res(TINFO, "shmat() didn't attach a nil-page");
> +
> +	((char *)addr)[0] = 'A';


So if shmat() fails we try to write to (char*)-1 address, that does not
sound right. Why don't we exit the test with TPASS in that case and skip
the part that tries to write to invalid address?

Or at least dereference NULL here instead of the address returned from
shmat() since that is guaranteed to SEGFAULT.

> +	tst_res(TINFO, "shmat() wrote data to shmaddr:%p unexpectedly", addr);
> +
> +	SAFE_SHMDT(addr);
> +
> +	exit(0);
> +}
> +
> +static void do_shmat(unsigned int n)
> +{
> +	pid_t pid;
> +	int status;
> +	struct tcase *tc = &tcases[n];
> +
> +	pid = SAFE_FORK();
> +	if (!pid)
> +		verify_shmat(tc->exp_usr);
> +
> +	SAFE_WAITPID(pid, &status, 0);
> +
> +	if (WIFEXITED(status)) {
> +		tst_res(TFAIL, "%s mapped nil-page in shmat() unexpectedly",
> +			tc->des);
> +		return;
> +	}
> +
> +	if (WIFSIGNALED(status) && WTERMSIG(status) == SIGSEGV) {
> +		tst_res(TPASS, "%s didn't map nil-page in shmat(), and was "
> +			"killed by %s as expected", tc->des,
> +			tst_strsig(WTERMSIG(status)));
> +	} else {
> +		tst_res(TFAIL, "%s didn't map nil-page in shmat(), and was "
> +			"killed by %s unexpectedly", tc->des,
> +			tst_strsig(WTERMSIG(status)));
> +	}
> +}
> +
> +static void setup(void)
> +{
> +	key_t shm_key;
> +
> +	shm_key = GETIPCKEY();
> +	shm_id = SAFE_SHMGET(shm_key, 4096, 0777 | IPC_CREAT);
> +}
> +
> +static void cleanup(void)
> +{
> +	if (shm_id != -1)
> +		SAFE_SHMCTL(shm_id, IPC_RMID, NULL);
> +}
> +
> +static struct tst_test test = {
> +	.tid = "shmat03",
> +	.needs_root = 1,
> +	.forks_child = 1,
> +	.test = do_shmat,
> +	.tcnt = ARRAY_SIZE(tcases),
> +	.setup = setup,
> +	.cleanup = cleanup
> +};
> -- 
> 1.8.3.1
> 
> 
> 
> 
> -- 
> Mailing list info: https://lists.linux.it/listinfo/ltp

-- 
Cyril Hrubis
chrubis@suse.cz