libbb: make bb_common_bufsiz1 1 kbyte, add capability to use bss tail for it

The config item is FEATURE_USE_BSS_TAIL. When it is off (default):

function                                             old     new   delta
read_config                                          210     228     +18
doCommands                                          2279    2294     +15
ipneigh_list_or_flush                                763     772      +9
ipaddr_list_or_flush                                1256    1261      +5
display_process_list                                1301    1306      +5
conspy_main                                         1378    1383      +5
do_lzo_compress                                      352     355      +3
do_lzo_decompress                                    565     567      +2
push                                                  46      44      -2
inetd_main                                          2136    2134      -2
uevent_main                                          421     418      -3
addLines                                              97      92      -5
bb_common_bufsiz1                                   8193    1024   -7169
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 8/5 up/down: 62/-7181)        Total: -7119 bytes
   text	   data	    bss	    dec	    hex	filename
 829850	   4086	   9080	 843016	  cdd08	busybox_old
 829901	   4086	   1904	 835891	  cc133	busybox_unstripped

FEATURE_USE_BSS_TAIL=y:

read_config                                          210     228     +18
doCommands                                          2279    2294     +15
ipneigh_list_or_flush                                763     772      +9
ipaddr_list_or_flush                                1256    1261      +5
display_process_list                                1301    1306      +5
conspy_main                                         1378    1383      +5
do_lzo_compress                                      352     355      +3
do_lzo_decompress                                    565     567      +2
inetd_main                                          2136    2134      -2
bb_common_bufsiz1                                   8193       -   -8193
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 8/1 up/down: 62/-8195)        Total: -8133 bytes
   text	   data	    bss	    dec	    hex	filename
 829850	   4086	   9080	 843016	  cdd08	busybox_old
 829911	   4086	    880	 834877	  cbd3d	busybox_unstripped

FIXME: setup_common_bufsiz() calls are missing.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

10 files changed, 28 insertions, 13 deletions

diff --git a/miscutils/chat.c b/miscutils/chat.c
index bd2abc24a..25850dd20 100644
--- a/miscutils/chat.c
+++ b/miscutils/chat.c
@@ -17,6 +17,7 @@
 //usage:       "chat '' ATZ OK ATD123456 CONNECT '' ogin: pppuser word: ppppass '~'"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 // default timeout: 45 sec
 #define DEFAULT_CHAT_TIMEOUT 45*1000
diff --git a/miscutils/conspy.c b/miscutils/conspy.c
index 1a46a4340..0d96a5f9a 100644
--- a/miscutils/conspy.c
+++ b/miscutils/conspy.c
@@ -42,6 +42,7 @@
 //usage:     "\n	-y LINE	Starting line"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <sys/kd.h>
 
 #define ESC "\033"
@@ -363,7 +364,8 @@ 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        keybuf bb_common_bufsiz1
+#define sizeof_keybuf COMMON_BUFSIZE
 	struct termios termbuf;
 	unsigned opts;
 	unsigned ttynum;
@@ -513,7 +515,7 @@ 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, sizeof_keybuf - G.key_count);
 			if (bytes_read < 0)
 				goto abort;
 
diff --git a/miscutils/crond.c b/miscutils/crond.c
index eb327f855..8536d43c5 100644
--- a/miscutils/crond.c
+++ b/miscutils/crond.c
@@ -60,6 +60,7 @@
 //usage:     "\n	-c DIR	Cron dir. Default:"CONFIG_FEATURE_CROND_DIR"/crontabs"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <syslog.h>
 
 /* glibc frees previous setenv'ed value when we do next setenv()
@@ -140,7 +141,7 @@ struct globals {
 	char *env_var_logname;
 #endif
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	G.log_level = 8; \
 	G.crontab_dir_name = CRONTABS; \
diff --git a/miscutils/dc.c b/miscutils/dc.c
index 9c74172ba..3fbb89f5b 100644
--- a/miscutils/dc.c
+++ b/miscutils/dc.c
@@ -4,6 +4,7 @@
  */
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <math.h>
 
 //usage:#define dc_trivial_usage
@@ -47,7 +48,7 @@ struct globals {
 	double stack[1];
 } FIX_ALIASING;
 enum { STACK_SIZE = (COMMON_BUFSIZE - offsetof(struct globals, stack)) / sizeof(double) };
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define pointer   (G.pointer   )
 #define base      (G.base      )
 #define stack     (G.stack     )
diff --git a/miscutils/fbsplash.c b/miscutils/fbsplash.c
index 9557c41db..b26ad2c15 100644
--- a/miscutils/fbsplash.c
+++ b/miscutils/fbsplash.c
@@ -34,6 +34,7 @@
 //usage:     "\n			commands: 'NN' (% for progress bar) or 'exit'"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <linux/fb.h>
 
 /* If you want logging messages on /tmp/fbsplash.log... */
@@ -372,11 +373,12 @@ 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        concat_buf bb_common_bufsiz1
+#define sizeof_concat_buf COMMON_BUFSIZE
 	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 + sizeof_concat_buf - read_ptr;
 		if (rem < 2
 		 || fgets(read_ptr, rem, theme_file) == NULL
 		) {
diff --git a/miscutils/hdparm.c b/miscutils/hdparm.c
index 8e201ac35..9e141de2f 100644
--- a/miscutils/hdparm.c
+++ b/miscutils/hdparm.c
@@ -63,6 +63,7 @@
 //usage:     "\n	-z	Reread partition table"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 /* must be _after_ libbb.h: */
 #include <linux/hdreg.h>
 #include <sys/mount.h>
@@ -367,7 +368,7 @@ struct globals {
 	unsigned char flushcache[4] = { WIN_FLUSHCACHE, 0, 0, 0 };
 #endif
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define get_identity       (G.get_identity           )
 #define get_geom           (G.get_geom               )
 #define do_flush           (G.do_flush               )
diff --git a/miscutils/i2c_tools.c b/miscutils/i2c_tools.c
index aa1c7c5cc..57bb72ae7 100644
--- a/miscutils/i2c_tools.c
+++ b/miscutils/i2c_tools.c
@@ -60,6 +60,7 @@
  */
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 #include <linux/i2c.h>
 #include <linux/i2c-dev.h>
diff --git a/miscutils/inotifyd.c b/miscutils/inotifyd.c
index 908d657fd..1d28e8f99 100644
--- a/miscutils/inotifyd.c
+++ b/miscutils/inotifyd.c
@@ -56,6 +56,7 @@
 //usage:     "\nWhen x event happens for all FILEs, inotifyd exits."
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <sys/inotify.h>
 
 static const char mask_names[] ALIGN1 =
@@ -162,8 +163,9 @@ int inotifyd_main(int argc, char **argv)
 		// read out all pending events
 		// (NB: len must be int, not ssize_t or long!)
 		xioctl(pfd.fd, FIONREAD, &len);
-#define eventbuf bb_common_bufsiz1
-		ie = buf = (len <= sizeof(eventbuf)) ? eventbuf : xmalloc(len);
+#define        eventbuf bb_common_bufsiz1
+#define sizeof_eventbuf COMMON_BUFSIZE
+		ie = buf = (len <= sizeof_eventbuf) ? 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 ccdb15fdc..94ecf1686 100644
--- a/miscutils/less.c
+++ b/miscutils/less.c
@@ -127,6 +127,7 @@
 #include <sched.h>  /* sched_yield() */
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #if ENABLE_FEATURE_LESS_REGEXP
 #include "xregex.h"
 #endif
@@ -439,7 +440,8 @@ static int at_end(void)
  */
 static void read_lines(void)
 {
-#define readbuf bb_common_bufsiz1
+#define        readbuf bb_common_bufsiz1
+#define sizeof_readbuf COMMON_BUFSIZE
 	char *current_line, *p;
 	int w = width;
 	char last_terminated = terminated;
@@ -480,7 +482,7 @@ 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, sizeof_readbuf);
 					if (errno != EAGAIN)
 						break;
 					t = time(NULL);
diff --git a/miscutils/microcom.c b/miscutils/microcom.c
index 5e29a1acd..5eb2e6743 100644
--- a/miscutils/microcom.c
+++ b/miscutils/microcom.c
@@ -19,6 +19,7 @@
 //usage:     "\n	-X	Disable special meaning of NUL and Ctrl-X from stdin"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 // set raw tty mode
 static void xget1(int fd, struct termios *t, struct termios *oldt)
@@ -155,10 +156,11 @@ int microcom_main(int argc UNUSED_PARAM, char **argv)
 skip_write: ;
 		}
 		if (pfd[0].revents) {
-#define iobuf bb_common_bufsiz1
+#define        iobuf bb_common_bufsiz1
+#define sizeof_iobuf COMMON_BUFSIZE
 			ssize_t len;
 			// read from device -> write to stdout
-			len = safe_read(sfd, iobuf, sizeof(iobuf));
+			len = safe_read(sfd, iobuf, sizeof_iobuf);
 			if (len > 0)
 				full_write(STDOUT_FILENO, iobuf, len);
 			else {