Revert "Revert "tree-wide: use sizeof on static arrays""

This reverts commit 2fb7cf0.

The problem wasn't caused by the reverted commit and was fixed in

commit 0c9b1f8 ("macro: calculate buffer lengths correctly")

The full explanation can be taken from the following irc excerpt from
the #lxc-dev channel:

│19:54:47 brauner | there was a bug in one of the standard macros we used
│19:55:01 brauner | and the changes by INTTYPE_TO_STRLEN() caused the issue to surface
│19:55:03 brauner | which is good
│19:55:16 brauner | i sent a branch and stgraber merged it that fixes it
│19:57:56  Blub\0 | so...
│19:58:31  Blub\0 | still doesn't explain how it was the sizeof() patch
│20:07:14 brauner | Blub\0: so here's the long explanation
│20:07:35 brauner | Blub\0: stgraber bumped pid_max on our jenkins test builders
│20:07:53 brauner | Blub\0: because we're running *a lot* of containers
│20:07:56 brauner | in any case
│20:08:06 brauner | there was a buffer
│20:08:12 brauner | LXC_LSMATTRLEN
│20:08:59 brauner | it used to be
│20:09:03 brauner | -/* /proc/pid-to-str/attr/current = (5 + INTTYPE_TO_STRLEN(pid_t) + 7 + 1) */
│20:09:03 brauner | -#define LXC_LSMATTRLEN (5 + INTTYPE_TO_STRLEN(pid_t) + 7 + 1)
│20:09:14 brauner | which one can see is wrong
│20:09:21 brauner | before the INTTYPE patchset
│20:09:40 brauner | INTTYPE_TO_STRLEN(pid_t) was LXC_NUMSTRLEN64
│20:09:45 brauner | which gave you 21 chars
│20:09:57 brauner | so it accounted for the missing parts
│20:10:03 brauner | because the correct macro should've been
│20:10:17 brauner | +/* /proc/        = 6
│20:10:17 brauner | + *               +
│20:10:17 brauner | + * <pid-as-str>  = INTTYPE_TO_STRLEN(pid_t)
│20:10:17 brauner | + *               +
│20:10:17 brauner | + * /attr/        = 6
│20:10:17 brauner | + *               +
│20:10:17 brauner | + * /current      = 8
│20:10:17 brauner | + *               +
│20:10:17 brauner | + * \0            = 1
│20:10:17 brauner | + */
│20:10:17 brauner | +#define LXC_LSMATTRLEN (6 + INTTYPE_TO_STRLEN(pid_t) + 6 + 8 + 1)
│20:10:24  Blub\0 | still
│20:10:31 brauner | the issue was only seen
│20:10:39 brauner | when the pid number hit a specific maximum
│20:10:50  Blub\0 | the sizeof patch only changed instances of actual char buf[A_FIXED_NUMBER] + snprintf(buf, A_FIXED_NUMBER, ...)
│20:10:54 brauner | aka exceeded the newly shortened buffer
│20:11:42 brauner | your patch was a red herring
│20:12:03  Blub\0 | I guess
│20:12:06 brauner | it didn't cause it
│20:12:14 brauner | it just surfaced at the same time it was merged
│20:12:25  Blub\0 | so we can revert the revert then? :)
│20:12:35 brauner | yes, that was th eplan all along

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

src/lxc/caps.c

@@ -299,7 +299,7 @@ static long int _real_caps_last_cap(void)
 		char buf[INTTYPE_TO_STRLEN(int)];
 
 	again:
-		n = read(fd, buf, INTTYPE_TO_STRLEN(int));
+		n = read(fd, buf, sizeof(buf));
 		if (n < 0 && errno == EINTR) {
 			goto again;
 		} else if (n >= 0) {

src/lxc/cgroups/cgfsng.c

@@ -321,8 +321,8 @@ static char *lxc_cpumask_to_cpulist(uint32_t *bitarr, size_t nbits)
 		if (!is_set(i, bitarr))
 			continue;
 
-		ret = snprintf(numstr, INTTYPE_TO_STRLEN(size_t), "%zu", i);
-		if (ret < 0 || (size_t)ret >= INTTYPE_TO_STRLEN(size_t)) {
+		ret = snprintf(numstr, sizeof(numstr), "%zu", i);
+		if (ret < 0 || (size_t)ret >= sizeof(numstr)) {
 			lxc_free_array((void **)cpulist, free);
 			return NULL;
 		}

src/lxc/log.c

@@ -247,8 +247,8 @@ static int lxc_unix_epoch_to_utc(char *buf, size_t bufsize, const struct timespe
 	seconds = (time->tv_sec - d_in_s - h_in_s - (minutes * 60));
 
 	/* Make string from nanoseconds. */
-	ret = snprintf(nanosec, INTTYPE_TO_STRLEN(int64_t), "%"PRId64, (int64_t)time->tv_nsec);
-	if (ret < 0 || ret >= INTTYPE_TO_STRLEN(int64_t))
+	ret = snprintf(nanosec, sizeof(nanosec), "%"PRId64, (int64_t)time->tv_nsec);
+	if (ret < 0 || ret >= sizeof(nanosec))
 		return -1;
 
 	/* Create final timestamp for the log and shorten nanoseconds to 3

src/lxc/lxccontainer.c

@@ -1039,8 +1039,8 @@ static bool do_lxcapi_start(struct lxc_container *c, int useinit, char * const a
 		int ret, w;
 		char pidstr[INTTYPE_TO_STRLEN(int)];
 
-		w = snprintf(pidstr, INTTYPE_TO_STRLEN(int), "%d", (int)lxc_raw_getpid());
-		if (w < 0 || (size_t)w >= INTTYPE_TO_STRLEN(int)) {
+		w = snprintf(pidstr, sizeof(pidstr), "%d", (int)lxc_raw_getpid());
+		if (w < 0 || (size_t)w >= sizeof(pidstr)) {
 			free_init_cmd(init_cmd);
 			lxc_free_handler(handler);
 

src/lxc/monitor.c

@@ -371,8 +371,8 @@ int lxc_monitord_spawn(const char *lxcpath)
 
 	close(pipefd[0]);
 
-	ret = snprintf(pipefd_str, INTTYPE_TO_STRLEN(int), "%d", pipefd[1]);
-	if (ret < 0 || ret >= INTTYPE_TO_STRLEN(int)) {
+	ret = snprintf(pipefd_str, sizeof(pipefd_str), "%d", pipefd[1]);
+	if (ret < 0 || ret >= sizeof(pipefd_str)) {
 		ERROR("Failed to create pid argument to pass to monitord.");
 		_exit(EXIT_FAILURE);
 	}

src/lxc/tools/lxc_monitor.c

@@ -224,8 +224,8 @@ static int lxc_tool_monitord_spawn(const char *lxcpath)
 
 	close(pipefd[0]);
 
-	ret = snprintf(pipefd_str, INTTYPE_TO_STRLEN(int), "%d", pipefd[1]);
-	if (ret < 0 || ret >= INTTYPE_TO_STRLEN(int)) {
+	ret = snprintf(pipefd_str, sizeof(pipefd_str), "%d", pipefd[1]);
+	if (ret < 0 || ret >= sizeof(pipefd_str)) {
 		ERROR("Failed to create pid argument to pass to monitord");
 		_exit(EXIT_FAILURE);
 	}

src/lxc/utils.c

@@ -1165,7 +1165,7 @@ int lxc_mount_proc_if_needed(const char *rootfs)
 		return -1;
 	}
 
-	linklen = readlink(path, link, INTTYPE_TO_STRLEN(pid_t));
+	linklen = readlink(path, link, sizeof(link));
 
 	ret = snprintf(path, MAXPATHLEN, "%s/proc", rootfs);
 	if (ret < 0 || ret >= MAXPATHLEN) {
@@ -1179,7 +1179,7 @@ int lxc_mount_proc_if_needed(const char *rootfs)
 			return -1;
 
 		goto domount;
-	} else if (linklen >= INTTYPE_TO_STRLEN(pid_t)) {
+	} else if (linklen >= sizeof(link)) {
 		link[linklen - 1] = '\0';
 		ERROR("readlink returned truncated content: \"%s\"", link);
 		return -1;

src/tests/lxc-test-utils.c

@@ -252,14 +252,14 @@ void test_lxc_safe_uint(void)
 	lxc_test_assert_abort((-EINVAL == lxc_safe_uint("    -123", &n)));
 	lxc_test_assert_abort((-EINVAL == lxc_safe_uint("-123", &n)));
 
-	ret = snprintf(numstr, INTTYPE_TO_STRLEN(uint64_t), "%" PRIu64, (uint64_t)UINT_MAX);
-	if (ret < 0 || ret >= INTTYPE_TO_STRLEN(uint64_t))
+	ret = snprintf(numstr, sizeof(numstr), "%" PRIu64, (uint64_t)UINT_MAX);
+	if (ret < 0 || ret >= sizeof(numstr))
 		exit(EXIT_FAILURE);
 
 	lxc_test_assert_abort((0 == lxc_safe_uint(numstr, &n)) && n == UINT_MAX);
 
-	ret = snprintf(numstr, INTTYPE_TO_STRLEN(uint64_t), "%" PRIu64, (uint64_t)UINT_MAX + 1);
-	if (ret < 0 || ret >= INTTYPE_TO_STRLEN(uint64_t))
+	ret = snprintf(numstr, sizeof(numstr), "%" PRIu64, (uint64_t)UINT_MAX + 1);
+	if (ret < 0 || ret >= sizeof(numstr))
 		exit(EXIT_FAILURE);
 
 	lxc_test_assert_abort((-ERANGE == lxc_safe_uint(numstr, &n)));
@@ -285,26 +285,26 @@ void test_lxc_safe_int(void)
 	signed int n;
 	char numstr[INTTYPE_TO_STRLEN(uint64_t)];
 
-	ret = snprintf(numstr, INTTYPE_TO_STRLEN(uint64_t), "%" PRIu64, (uint64_t)INT_MAX);
-	if (ret < 0 || ret >= INTTYPE_TO_STRLEN(uint64_t))
+	ret = snprintf(numstr, sizeof(numstr), "%" PRIu64, (uint64_t)INT_MAX);
+	if (ret < 0 || ret >= sizeof(numstr))
 		exit(EXIT_FAILURE);
 
 	lxc_test_assert_abort((0 == lxc_safe_int(numstr, &n)) && n == INT_MAX);
 
-	ret = snprintf(numstr, INTTYPE_TO_STRLEN(uint64_t), "%" PRIu64, (uint64_t)INT_MAX + 1);
-	if (ret < 0 || ret >= INTTYPE_TO_STRLEN(uint64_t))
+	ret = snprintf(numstr, sizeof(numstr), "%" PRIu64, (uint64_t)INT_MAX + 1);
+	if (ret < 0 || ret >= sizeof(numstr))
 		exit(EXIT_FAILURE);
 
 	lxc_test_assert_abort((-ERANGE == lxc_safe_int(numstr, &n)));
 
-	ret = snprintf(numstr, INTTYPE_TO_STRLEN(int64_t), "%" PRId64, (int64_t)INT_MIN);
-	if (ret < 0 || ret >= INTTYPE_TO_STRLEN(int64_t))
+	ret = snprintf(numstr, sizeof(numstr), "%" PRId64, (int64_t)INT_MIN);
+	if (ret < 0 || ret >= sizeof(numstr))
 		exit(EXIT_FAILURE);
 
 	lxc_test_assert_abort((0 == lxc_safe_int(numstr, &n)) && n == INT_MIN);
 
-	ret = snprintf(numstr, INTTYPE_TO_STRLEN(int64_t), "%" PRId64, (int64_t)INT_MIN - 1);
-	if (ret < 0 || ret >= INTTYPE_TO_STRLEN(int64_t))
+	ret = snprintf(numstr, sizeof(numstr), "%" PRId64, (int64_t)INT_MIN - 1);
+	if (ret < 0 || ret >= sizeof(numstr))
 		exit(EXIT_FAILURE);
 
 	lxc_test_assert_abort((-ERANGE == lxc_safe_int(numstr, &n)));