diff --git a/archival/tar.c b/archival/tar.c
index caf4363de..346a9404e 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -162,6 +162,7 @@
 
 
 #define block_buf bb_common_bufsiz1
+#define INIT_G() do { setup_common_bufsiz(); } while (0)
 
 
 #if ENABLE_FEATURE_TAR_CREATE
@@ -964,6 +965,7 @@ int tar_main(int argc UNUSED_PARAM, char **argv)
 #if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
 	llist_t *excludes = NULL;
 #endif
+	INIT_G();
 
 	/* Initialise default values */
 	tar_handle = init_handle();
diff --git a/console-tools/dumpkmap.c b/console-tools/dumpkmap.c
index 6412dffc8..b6fd466dc 100644
--- a/console-tools/dumpkmap.c
+++ b/console-tools/dumpkmap.c
@@ -38,6 +38,7 @@ int dumpkmap_main(int argc UNUSED_PARAM, char **argv)
 	struct kbentry ke;
 	int i, j, fd;
 #define flags bb_common_bufsiz1
+	setup_common_bufsiz();
 
 	/* When user accidentally runs "dumpkmap FILE"
 	 * instead of "dumpkmap >FILE", we'd dump binary stuff to tty.
diff --git a/coreutils/catv.c b/coreutils/catv.c
index 801d2451d..0e71368a5 100644
--- a/coreutils/catv.c
+++ b/coreutils/catv.c
@@ -49,6 +49,9 @@ int catv_main(int argc UNUSED_PARAM, char **argv)
 	/* Read from stdin if there's nothing else to do. */
 	if (!argv[0])
 		*--argv = (char*)"-";
+
+#define read_buf bb_common_bufsiz1
+	setup_common_bufsiz();
 	do {
 		fd = open_or_warn_stdin(*argv);
 		if (fd < 0) {
@@ -58,7 +61,6 @@ int catv_main(int argc UNUSED_PARAM, char **argv)
 		for (;;) {
 			int i, res;
 
-#define read_buf bb_common_bufsiz1
 			res = read(fd, read_buf, COMMON_BUFSIZE);
 			if (res < 0)
 				retval = EXIT_FAILURE;
diff --git a/coreutils/cksum.c b/coreutils/cksum.c
index d8351e7c6..8a8a39f68 100644
--- a/coreutils/cksum.c
+++ b/coreutils/cksum.c
@@ -33,6 +33,7 @@ int cksum_main(int argc UNUSED_PARAM, char **argv)
 	argv++;
 #endif
 
+	setup_common_bufsiz();
 	do {
 		int fd = open_or_warn_stdin(*argv ? *argv : bb_msg_standard_input);
 
@@ -43,9 +44,8 @@ int cksum_main(int argc UNUSED_PARAM, char **argv)
 		crc = 0;
 		length = 0;
 
-#define        read_buf bb_common_bufsiz1
-#define sizeof_read_buf COMMON_BUFSIZE
-		while ((bytes_read = safe_read(fd, read_buf, sizeof_read_buf)) > 0) {
+#define read_buf bb_common_bufsiz1
+		while ((bytes_read = safe_read(fd, read_buf, COMMON_BUFSIZE)) > 0) {
 			length += bytes_read;
 			crc = crc32_block_endian1(crc, read_buf, bytes_read, crc32_table);
 		}
diff --git a/coreutils/date.c b/coreutils/date.c
index 59b4b8f2a..ff3214d85 100644
--- a/coreutils/date.c
+++ b/coreutils/date.c
@@ -368,8 +368,8 @@ int date_main(int argc UNUSED_PARAM, char **argv)
 	}
 #endif
 
-#define        date_buf bb_common_bufsiz1
-#define sizeof_date_buf COMMON_BUFSIZE
+#define date_buf bb_common_bufsiz1
+	setup_common_bufsiz();
 	if (*fmt_dt2str == '\0') {
 		/* With no format string, just print a blank line */
 		date_buf[0] = '\0';
@@ -379,7 +379,7 @@ int date_main(int argc UNUSED_PARAM, char **argv)
 			fmt_dt2str = (char*)"%Y.%m.%d-%H:%M:%S";
 		}
 		/* Generate output string */
-		strftime(date_buf, sizeof_date_buf, fmt_dt2str, &tm_time);
+		strftime(date_buf, COMMON_BUFSIZE, fmt_dt2str, &tm_time);
 	}
 	puts(date_buf);
 
diff --git a/coreutils/split.c b/coreutils/split.c
index b2da74e27..e67c3de66 100644
--- a/coreutils/split.c
+++ b/coreutils/split.c
@@ -79,6 +79,8 @@ int split_main(int argc UNUSED_PARAM, char **argv)
 	ssize_t bytes_read, to_write;
 	char *src;
 
+	setup_common_bufsiz();
+
 	opt_complementary = "?2:a+"; /* max 2 args; -a N */
 	opt = getopt32(argv, "l:b:a:", &count_p, &count_p, &suffix_len);
 
diff --git a/coreutils/stat.c b/coreutils/stat.c
index 78df9c948..ddcfcf2d7 100644
--- a/coreutils/stat.c
+++ b/coreutils/stat.c
@@ -158,10 +158,9 @@ static const char *human_time(time_t t)
 	/* coreutils 6.3 compat: */
 
 	/*static char buf[sizeof("YYYY-MM-DD HH:MM:SS.000000000")] ALIGN1;*/
-#define        buf bb_common_bufsiz1
-#define sizeof_buf COMMON_BUFSIZE
-
-	strcpy(strftime_YYYYMMDDHHMMSS(buf, sizeof_buf, &t), ".000000000");
+#define buf bb_common_bufsiz1
+	setup_common_bufsiz();
+	strcpy(strftime_YYYYMMDDHHMMSS(buf, COMMON_BUFSIZE, &t), ".000000000");
 	return buf;
 #undef buf
 }
diff --git a/coreutils/sum.c b/coreutils/sum.c
index cc6677221..ec9ed2a11 100644
--- a/coreutils/sum.c
+++ b/coreutils/sum.c
@@ -31,12 +31,14 @@ enum { SUM_BSD, PRINT_NAME, SUM_SYSV };
 /* Return 1 if successful.  */
 static unsigned sum_file(const char *file, unsigned type)
 {
-#define buf bb_common_bufsiz1
 	unsigned long long total_bytes = 0;
 	int fd, r;
 	/* The sum of all the input bytes, modulo (UINT_MAX + 1).  */
 	unsigned s = 0;
 
+#define buf bb_common_bufsiz1
+	setup_common_bufsiz();
+
 	fd = open_or_warn_stdin(file);
 	if (fd == -1)
 		return 0;
diff --git a/coreutils/tee.c b/coreutils/tee.c
index a0e177cbc..a68e9446f 100644
--- a/coreutils/tee.c
+++ b/coreutils/tee.c
@@ -37,8 +37,8 @@ int tee_main(int argc, char **argv)
 //TODO: make unconditional
 #if ENABLE_FEATURE_TEE_USE_BLOCK_IO
 	ssize_t c;
-# define        buf bb_common_bufsiz1
-# define sizeof_buf COMMON_BUFSIZE
+# define buf bb_common_bufsiz1
+	setup_common_bufsiz();
 #else
 	int c;
 #endif
@@ -81,7 +81,7 @@ int tee_main(int argc, char **argv)
 	/* names[0] will be filled later */
 
 #if ENABLE_FEATURE_TEE_USE_BLOCK_IO
-	while ((c = safe_read(STDIN_FILENO, buf, sizeof_buf)) > 0) {
+	while ((c = safe_read(STDIN_FILENO, buf, COMMON_BUFSIZE)) > 0) {
 		fp = files;
 		do
 			fwrite(buf, 1, c, *fp);
diff --git a/editors/diff.c b/editors/diff.c
index 3c8e9074a..ff269360f 100644
--- a/editors/diff.c
+++ b/editors/diff.c
@@ -749,6 +749,7 @@ static int diffreg(char *file[2])
 		fp[i] = fdopen(fd, "r");
 	}
 
+	setup_common_bufsiz();
 	while (1) {
 		const size_t sz = COMMON_BUFSIZE / 2;
 		char *const buf0 = bb_common_bufsiz1;
diff --git a/editors/ed.c b/editors/ed.c
index 8da7b1dd5..c028b78cb 100644
--- a/editors/ed.c
+++ b/editors/ed.c
@@ -33,12 +33,11 @@ typedef struct LINE {
 } LINE;
 
 
-#define        searchString bb_common_bufsiz1
-#define sizeof_searchString COMMON_BUFSIZE
+#define searchString bb_common_bufsiz1
 
 enum {
-	USERSIZE = sizeof_searchString > 1024 ? 1024
-	         : sizeof_searchString - 1, /* max line length typed in by user */
+	USERSIZE = COMMON_BUFSIZE > 1024 ? 1024
+	         : COMMON_BUFSIZE - 1, /* max line length typed in by user */
 	INITBUF_SIZE = 1024, /* initial buffer size */
 };
 
@@ -68,6 +67,7 @@ struct globals {
 #define lines              (G.lines             )
 #define marks              (G.marks             )
 #define INIT_G() do { \
+	setup_common_bufsiz(); \
 	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
 } while (0)
 
diff --git a/miscutils/chat.c b/miscutils/chat.c
index 25850dd20..6b429f2a6 100644
--- a/miscutils/chat.c
+++ b/miscutils/chat.c
@@ -286,9 +286,10 @@ int chat_main(int argc UNUSED_PARAM, char **argv)
 			    && poll(&pfd, 1, timeout) > 0
 			    && (pfd.revents & POLLIN)
 			) {
-#define buf bb_common_bufsiz1
 				llist_t *l;
 				ssize_t delta;
+#define buf bb_common_bufsiz1
+				setup_common_bufsiz();
 
 				// read next char from device
 				if (safe_read(STDIN_FILENO, buf+buf_len, 1) > 0) {
diff --git a/miscutils/conspy.c b/miscutils/conspy.c
index 0d96a5f9a..f6468c116 100644
--- a/miscutils/conspy.c
+++ b/miscutils/conspy.c
@@ -364,8 +364,6 @@ int conspy_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int conspy_main(int argc UNUSED_PARAM, char **argv)
 {
 	char tty_name[sizeof(DEV_TTY "NN")];
-#define        keybuf bb_common_bufsiz1
-#define sizeof_keybuf COMMON_BUFSIZE
 	struct termios termbuf;
 	unsigned opts;
 	unsigned ttynum;
@@ -384,6 +382,9 @@ int conspy_main(int argc UNUSED_PARAM, char **argv)
 
 	applet_long_options = getopt_longopts;
 #endif
+#define keybuf bb_common_bufsiz1
+	setup_common_bufsiz();
+
 	INIT_G();
 	strcpy(G.vcsa_name, DEV_VCSA);
 
@@ -515,7 +516,7 @@ int conspy_main(int argc UNUSED_PARAM, char **argv)
 		default:
 			// Read the keys pressed
 			k = keybuf + G.key_count;
-			bytes_read = read(G.kbd_fd, k, sizeof_keybuf - G.key_count);
+			bytes_read = read(G.kbd_fd, k, COMMON_BUFSIZE - G.key_count);
 			if (bytes_read < 0)
 				goto abort;
 
diff --git a/miscutils/fbsplash.c b/miscutils/fbsplash.c
index b26ad2c15..3ddf8a242 100644
--- a/miscutils/fbsplash.c
+++ b/miscutils/fbsplash.c
@@ -373,12 +373,13 @@ static void fb_drawimage(void)
 	 * - A raster of Width * Height pixels in triplets of rgb
 	 *   in pure binary by 1 or 2 bytes. (we support only 1 byte)
 	 */
-#define        concat_buf bb_common_bufsiz1
-#define sizeof_concat_buf COMMON_BUFSIZE
+#define concat_buf bb_common_bufsiz1
+	setup_common_bufsiz();
+
 	read_ptr = concat_buf;
 	while (1) {
 		int w, h, max_color_val;
-		int rem = concat_buf + sizeof_concat_buf - read_ptr;
+		int rem = concat_buf + COMMON_BUFSIZE - read_ptr;
 		if (rem < 2
 		 || fgets(read_ptr, rem, theme_file) == NULL
 		) {
diff --git a/miscutils/inotifyd.c b/miscutils/inotifyd.c
index 1d28e8f99..52db08ada 100644
--- a/miscutils/inotifyd.c
+++ b/miscutils/inotifyd.c
@@ -162,10 +162,10 @@ int inotifyd_main(int argc, char **argv)
 
 		// read out all pending events
 		// (NB: len must be int, not ssize_t or long!)
+#define eventbuf bb_common_bufsiz1
+		setup_common_bufsiz();
 		xioctl(pfd.fd, FIONREAD, &len);
-#define        eventbuf bb_common_bufsiz1
-#define sizeof_eventbuf COMMON_BUFSIZE
-		ie = buf = (len <= sizeof_eventbuf) ? eventbuf : xmalloc(len);
+		ie = buf = (len <= COMMON_BUFSIZE) ? eventbuf : xmalloc(len);
 		len = full_read(pfd.fd, buf, len);
 		// process events. N.B. events may vary in length
 		while (len > 0) {
diff --git a/miscutils/less.c b/miscutils/less.c
index 94ecf1686..d7076dbbc 100644
--- a/miscutils/less.c
+++ b/miscutils/less.c
@@ -440,8 +440,6 @@ static int at_end(void)
  */
 static void read_lines(void)
 {
-#define        readbuf bb_common_bufsiz1
-#define sizeof_readbuf COMMON_BUFSIZE
 	char *current_line, *p;
 	int w = width;
 	char last_terminated = terminated;
@@ -451,6 +449,9 @@ static void read_lines(void)
 	unsigned old_max_fline = max_fline;
 #endif
 
+#define readbuf bb_common_bufsiz1
+	setup_common_bufsiz();
+
 	/* (careful: max_fline can be -1) */
 	if (max_fline + 1 > MAXLINES)
 		return;
@@ -482,7 +483,7 @@ static void read_lines(void)
 					time_t t;
 
 					errno = 0;
-					eof_error = safe_read(STDIN_FILENO, readbuf, sizeof_readbuf);
+					eof_error = safe_read(STDIN_FILENO, readbuf, COMMON_BUFSIZE);
 					if (errno != EAGAIN)
 						break;
 					t = time(NULL);
diff --git a/miscutils/microcom.c b/miscutils/microcom.c
index 5eb2e6743..d9e8f9187 100644
--- a/miscutils/microcom.c
+++ b/miscutils/microcom.c
@@ -156,11 +156,11 @@ int microcom_main(int argc UNUSED_PARAM, char **argv)
 skip_write: ;
 		}
 		if (pfd[0].revents) {
-#define        iobuf bb_common_bufsiz1
-#define sizeof_iobuf COMMON_BUFSIZE
 			ssize_t len;
+#define iobuf bb_common_bufsiz1
+			setup_common_bufsiz();
 			// read from device -> write to stdout
-			len = safe_read(sfd, iobuf, sizeof_iobuf);
+			len = safe_read(sfd, iobuf, COMMON_BUFSIZE);
 			if (len > 0)
 				full_write(STDOUT_FILENO, iobuf, len);
 			else {
diff --git a/networking/httpd.c b/networking/httpd.c
index ef90770ac..abe83a458 100644
--- a/networking/httpd.c
+++ b/networking/httpd.c
@@ -370,6 +370,7 @@ enum {
 # define content_gzip     0
 #endif
 #define INIT_G() do { \
+	setup_common_bufsiz(); \
 	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
 	IF_FEATURE_HTTPD_BASIC_AUTH(g_realm = "Web Server Authentication";) \
 	IF_FEATURE_HTTPD_RANGES(range_start = -1;) \
diff --git a/networking/isrv_identd.c b/networking/isrv_identd.c
index f63ed8ee4..8a15926e5 100644
--- a/networking/isrv_identd.c
+++ b/networking/isrv_identd.c
@@ -29,8 +29,7 @@ typedef struct identd_buf_t {
 	char buf[64 - sizeof(int)];
 } identd_buf_t;
 
-#define        bogouser bb_common_bufsiz1
-#define sizeof_bogouser COMMON_BUFSIZE
+#define bogouser bb_common_bufsiz1
 
 static int new_peer(isrv_state_t *state, int fd)
 {
@@ -117,10 +116,12 @@ int fakeidentd_main(int argc UNUSED_PARAM, char **argv)
 	unsigned opt;
 	int fd;
 
+	setup_common_bufsiz();
+
 	opt = getopt32(argv, "fiwb:", &bind_address);
 	strcpy(bogouser, "nobody");
 	if (argv[optind])
-		strncpy(bogouser, argv[optind], sizeof_bogouser - 1);
+		strncpy(bogouser, argv[optind], COMMON_BUFSIZE - 1);
 
 	/* Daemonize if no -f and no -i and no -w */
 	if (!(opt & OPT_fiw))
diff --git a/networking/libiproute/ipaddress.c b/networking/libiproute/ipaddress.c
index 2c0f514c7..d9e099607 100644
--- a/networking/libiproute/ipaddress.c
+++ b/networking/libiproute/ipaddress.c
@@ -41,7 +41,7 @@ struct filter_t {
 typedef struct filter_t filter_t;
 
 #define G_filter (*(filter_t*)bb_common_bufsiz1)
-
+#define INIT_G() do { setup_common_bufsiz(); } while (0)
 
 static void print_link_flags(unsigned flags, unsigned mdown)
 {
@@ -745,6 +745,9 @@ int FAST_FUNC do_ipaddr(char **argv)
 		/* 0    1         2      3          4         5       6       7      8 */
 		"add\0""change\0""chg\0""replace\0""delete\0""list\0""show\0""lst\0""flush\0";
 	int cmd = 2;
+
+	INIT_G();
+
 	if (*argv) {
 		cmd = index_in_substrings(commands, *argv);
 		if (cmd < 0)
diff --git a/networking/libiproute/ipneigh.c b/networking/libiproute/ipneigh.c
index 151d3d109..d2028b7b6 100644
--- a/networking/libiproute/ipneigh.c
+++ b/networking/libiproute/ipneigh.c
@@ -42,6 +42,7 @@ struct filter_t {
 typedef struct filter_t filter_t;
 
 #define G_filter (*(filter_t*)bb_common_bufsiz1)
+#define INIT_G() do { setup_common_bufsiz(); } while (0)
 
 static int flush_update(void)
 {
@@ -339,6 +340,8 @@ int FAST_FUNC do_ipneigh(char **argv)
 		/*0-1*/	"show\0"  "flush\0";
 	int command_num;
 
+	INIT_G();
+
 	if (!*argv)
 		return ipneigh_list_or_flush(argv, 0);
 
diff --git a/networking/libiproute/iproute.c b/networking/libiproute/iproute.c
index 34d4f4758..e674e9a0d 100644
--- a/networking/libiproute/iproute.c
+++ b/networking/libiproute/iproute.c
@@ -45,6 +45,7 @@ struct filter_t {
 typedef struct filter_t filter_t;
 
 #define G_filter (*(filter_t*)bb_common_bufsiz1)
+#define INIT_G() do { setup_common_bufsiz(); } while (0)
 
 static int flush_update(void)
 {
@@ -903,6 +904,8 @@ int FAST_FUNC do_iproute(char **argv)
 	unsigned flags = 0;
 	int cmd = RTM_NEWROUTE;
 
+	INIT_G();
+
 	if (!*argv)
 		return iproute_list_or_flush(argv, 0);
 
diff --git a/networking/nc.c b/networking/nc.c
index 50edee450..13a9b48a8 100644
--- a/networking/nc.c
+++ b/networking/nc.c
@@ -239,6 +239,8 @@ int nc_main(int argc, char **argv)
 	FD_SET(cfd, &readfds);
 	FD_SET(STDIN_FILENO, &readfds);
 
+#define iobuf bb_common_bufsiz1
+	setup_common_bufsiz();
 	for (;;) {
 		int fd;
 		int ofd;
@@ -249,7 +251,6 @@ int nc_main(int argc, char **argv)
 		if (select(cfd + 1, &testfds, NULL, NULL, NULL) < 0)
 			bb_perror_msg_and_die("select");
 
-#define iobuf bb_common_bufsiz1
 		fd = STDIN_FILENO;
 		while (1) {
 			if (FD_ISSET(fd, &testfds)) {
diff --git a/procps/nmeter.c b/procps/nmeter.c
index efa3d553d..3eac2d3b2 100644
--- a/procps/nmeter.c
+++ b/procps/nmeter.c
@@ -109,16 +109,15 @@ struct globals {
 #define proc_meminfo       (G.proc_meminfo      )
 #define proc_diskstats     (G.proc_diskstats    )
 #define proc_sys_fs_filenr (G.proc_sys_fs_filenr)
+#define outbuf bb_common_bufsiz1
 #define INIT_G() do { \
+	setup_common_bufsiz(); \
 	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
 	cur_outbuf = outbuf; \
 	G.final_char = '\n'; \
 	G.deltanz = G.delta = 1000000; \
 } while (0)
 
-#define        outbuf bb_common_bufsiz1
-#define sizeof_outbuf COMMON_BUFSIZE
-
 static inline void reset_outbuf(void)
 {
 	cur_outbuf = outbuf;
@@ -141,7 +140,7 @@ static void print_outbuf(void)
 static void put(const char *s)
 {
 	char *p = cur_outbuf;
-	int sz = outbuf + sizeof_outbuf - p;
+	int sz = outbuf + COMMON_BUFSIZE - p;
 	while (*s && --sz >= 0)
 		*p++ = *s++;
 	cur_outbuf = p;
@@ -149,7 +148,7 @@ static void put(const char *s)
 
 static void put_c(char c)
 {
-	if (cur_outbuf < outbuf + sizeof_outbuf)
+	if (cur_outbuf < outbuf + COMMON_BUFSIZE)
 		*cur_outbuf++ = c;
 }
 
diff --git a/runit/svlogd.c b/runit/svlogd.c
index 09efdb695..7cae81cb2 100644
--- a/runit/svlogd.c
+++ b/runit/svlogd.c
@@ -234,7 +234,9 @@ struct globals {
 #define blocked_sigset (G.blocked_sigset)
 #define fl_flag_0      (G.fl_flag_0     )
 #define dirn           (G.dirn          )
+#define line bb_common_bufsiz1
 #define INIT_G() do { \
+	setup_common_bufsiz(); \
 	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
 	linemax = 1000; \
 	/*buflen = 1024;*/ \
@@ -242,8 +244,6 @@ struct globals {
 	replace = ""; \
 } while (0)
 
-#define line bb_common_bufsiz1
-
 
 #define FATAL "fatal: "
 #define WARNING "warning: "
diff --git a/sysklogd/klogd.c b/sysklogd/klogd.c
index 845c49a5e..4db72110d 100644
--- a/sysklogd/klogd.c
+++ b/sysklogd/klogd.c
@@ -146,10 +146,9 @@ static void klogd_close(void)
 
 #endif
 
-#define        log_buffer bb_common_bufsiz1
-#define sizeof_log_buffer COMMON_BUFSIZE
+#define log_buffer bb_common_bufsiz1
 enum {
-	KLOGD_LOGBUF_SIZE = sizeof_log_buffer,
+	KLOGD_LOGBUF_SIZE = COMMON_BUFSIZE,
 	OPT_LEVEL      = (1 << 0),
 	OPT_FOREGROUND = (1 << 1),
 };
@@ -175,6 +174,8 @@ int klogd_main(int argc UNUSED_PARAM, char **argv)
 	int opt;
 	int used;
 
+	setup_common_bufsiz();
+
 	opt = getopt32(argv, "c:n", &opt_c);
 	if (opt & OPT_LEVEL) {
 		/* Valid levels are between 1 and 8 */
diff --git a/sysklogd/logger.c b/sysklogd/logger.c
index b3ca85703..f9eafeb25 100644
--- a/sysklogd/logger.c
+++ b/sysklogd/logger.c
@@ -99,6 +99,8 @@ int logger_main(int argc UNUSED_PARAM, char **argv)
 	int opt;
 	int i = 0;
 
+	setup_common_bufsiz();
+
 	/* Fill out the name string early (may be overwritten later) */
 	str_t = uid2uname_utoa(geteuid());
 
diff --git a/util-linux/script.c b/util-linux/script.c
index 6195161bc..86475c1f1 100644
--- a/util-linux/script.c
+++ b/util-linux/script.c
@@ -109,12 +109,12 @@ int script_main(int argc UNUSED_PARAM, char **argv)
 
 	if (child_pid) {
 		/* parent */
-#define        buf bb_common_bufsiz1
-#define sizeof_buf COMMON_BUFSIZE
 		struct pollfd pfd[2];
 		int outfd, count, loop;
 		double oldtime = ENABLE_SCRIPTREPLAY ? time(NULL) : 0;
 		smallint fd_count = 2;
+#define buf bb_common_bufsiz1
+		setup_common_bufsiz();
 
 		outfd = xopen(fname, mode);
 		pfd[0].fd = pty;
@@ -136,7 +136,7 @@ int script_main(int argc UNUSED_PARAM, char **argv)
 			}
 			if (pfd[0].revents) {
 				errno = 0;
-				count = safe_read(pty, buf, sizeof_buf);
+				count = safe_read(pty, buf, COMMON_BUFSIZE);
 				if (count <= 0 && errno != EAGAIN) {
 					/* err/eof from pty: exit */
 					goto restore;
@@ -159,7 +159,7 @@ int script_main(int argc UNUSED_PARAM, char **argv)
 				}
 			}
 			if (pfd[1].revents) {
-				count = safe_read(STDIN_FILENO, buf, sizeof_buf);
+				count = safe_read(STDIN_FILENO, buf, COMMON_BUFSIZE);
 				if (count <= 0) {
 					/* err/eof from stdin: don't read stdin anymore */
 					pfd[1].revents = 0;
@@ -178,7 +178,7 @@ int script_main(int argc UNUSED_PARAM, char **argv)
 		 * (util-linux's script doesn't do this. buggy :) */
 		loop = 999;
 		/* pty is in O_NONBLOCK mode, we exit as soon as buffer is empty */
-		while (--loop && (count = safe_read(pty, buf, sizeof_buf)) > 0) {
+		while (--loop && (count = safe_read(pty, buf, COMMON_BUFSIZE)) > 0) {
 			full_write(STDOUT_FILENO, buf, count);
 			full_write(outfd, buf, count);
 		}
diff --git a/util-linux/umount.c b/util-linux/umount.c
index be0300394..91da69674 100644
--- a/util-linux/umount.c
+++ b/util-linux/umount.c
@@ -103,6 +103,7 @@ int umount_main(int argc UNUSED_PARAM, char **argv)
 		if (opt & OPT_ALL)
 			bb_error_msg_and_die("can't open '%s'", bb_path_mtab_file);
 	} else {
+		setup_common_bufsiz();
 		while (getmntent_r(fp, &me, bb_common_bufsiz1, COMMON_BUFSIZE)) {
 			/* Match fstype if passed */
 			if (!match_fstype(&me, fstype))