Add readprofile applet support.

diff --git a/include/applets.h b/include/applets.h
index 4ef5ed7..6aa67f5 100644
--- a/include/applets.h
+++ b/include/applets.h
@@ -485,6 +485,9 @@
 #ifdef CONFIG_READLINK
 	APPLET(readlink, readlink_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)
 #endif
+#ifdef CONFIG_READPROFILE
+	APPLET(readprofile, readprofile_main, _BB_DIR_USR_SBIN, _BB_SUID_NEVER)
+#endif
 #ifdef CONFIG_REALPATH
 	APPLET(realpath, realpath_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)
 #endif
diff --git a/include/usage.h b/include/usage.h
index d634985..ae858bd 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -2091,6 +2091,21 @@
 	USAGE_READLINK_FOLLOW("\n\nOptions:\n" \
 	"\t-f\tcanonicalize by following all symlinks")
 
+#define readprofile_trivial_usage \
+	"[OPTIONS]..."
+#define readprofile_full_usage \
+	"Options:\n" \
+	"\t -m <mapfile>  (default: /boot/System.map)\n" \
+	"\t -p <profile>  (default: /proc/profile)\n" \
+	"\t -M <mult>     set the profiling multiplier to <mult>\n" \
+	"\t -i            print only info about the sampling step\n" \
+	"\t -v            print verbose data\n" \
+	"\t -a            print all symbols, even if count is 0\n" \
+	"\t -b            print individual histogram-bin counts\n" \
+	"\t -s            print individual counters within functions\n" \
+	"\t -r            reset all the counters (root only)\n" \
+	"\t -n            disable byte order auto-detection"
+
 #define realpath_trivial_usage \
 	"pathname  ..."
 #define realpath_full_usage \
diff --git a/util-linux/Config.in b/util-linux/Config.in
index c47a42d..3c990b9 100644
--- a/util-linux/Config.in
+++ b/util-linux/Config.in
@@ -351,5 +351,11 @@
 	  value is /etc/mtab, which is where this file is located on most desktop
 	  Linux systems.
 
+config CONFIG_READPROFILE
+	bool "readprofile"
+	default n
+	help
+	  This allows you to parse /proc/profile for basic profiling.
+
 endmenu
 
diff --git a/util-linux/Makefile.in b/util-linux/Makefile.in
index 2747b4f..9aaaf9f 100644
--- a/util-linux/Makefile.in
+++ b/util-linux/Makefile.in
@@ -44,6 +44,7 @@
 UTILLINUX-$(CONFIG_RDATE)		+=rdate.o
 UTILLINUX-$(CONFIG_SWAPONOFF)		+=swaponoff.o
 UTILLINUX-$(CONFIG_UMOUNT)		+=umount.o
+UTILLINUX-$(CONFIG_READPROFILE)		+=readprofile.o
 
 libraries-y+=$(UTILLINUX_DIR)$(UTILLINUX_AR)
 
diff --git a/util-linux/readprofile.c b/util-linux/readprofile.c
new file mode 100644
index 0000000..9563580
--- /dev/null
+++ b/util-linux/readprofile.c
@@ -0,0 +1,302 @@
+/*
+ *  readprofile.c - used to read /proc/profile
+ *
+ *  Copyright (C) 1994,1996 Alessandro Rubini (rubini@ipvvis.unipv.it)
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/*
+ * 1999-02-22 Arkadiusz Mi¶kiewicz <misiek@pld.ORG.PL>
+ * - added Native Language Support
+ * 1999-09-01 Stephane Eranian <eranian@cello.hpl.hp.com>
+ * - 64bit clean patch
+ * 3Feb2001 Andrew Morton <andrewm@uow.edu.au>
+ * - -M option to write profile multiplier.
+ * 2001-11-07 Werner Almesberger <wa@almesberger.net>
+ * - byte order auto-detection and -n option
+ * 2001-11-09 Werner Almesberger <wa@almesberger.net>
+ * - skip step size (index 0)
+ * 2002-03-09 John Levon <moz@compsoc.man.ac.uk>
+ * - make maplineno do something
+ * 2002-11-28 Mads Martin Joergensen +
+ * - also try /boot/System.map-`uname -r`
+ * 2003-04-09 Werner Almesberger <wa@almesberger.net>
+ * - fixed off-by eight error and improved heuristics in byte order detection
+ * 2003-08-12 Nikita Danilov <Nikita@Namesys.COM>
+ * - added -s option; example of use:
+ * "readprofile -s -m /boot/System.map-test | grep __d_lookup | sort -n -k3"
+ *
+ * Taken from util-linux and adapted for busybox by
+ * Paul Mundt <lethal@linux-sh.org>.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/utsname.h>
+
+#include "busybox.h"
+
+#define S_LEN 128
+
+/* These are the defaults */
+static char defaultmap[]="/boot/System.map";
+static char defaultpro[]="/proc/profile";
+
+int readprofile_main(int argc, char **argv)
+{
+	FILE *map;
+	int proFd;
+	char *mapFile, *proFile, *mult=0;
+	unsigned long len=0, indx=1;
+	unsigned long long add0=0;
+	unsigned int step;
+	unsigned int *buf, total, fn_len;
+	unsigned long long fn_add, next_add;          /* current and next address */
+	char fn_name[S_LEN], next_name[S_LEN];   /* current and next name */
+	char mode[8];
+	int c;
+	int optAll=0, optInfo=0, optReset=0, optVerbose=0, optNative=0;
+	int optBins=0, optSub=0;
+	char mapline[S_LEN];
+	int maplineno=1;
+	int header_printed;
+
+#define next (current^1)
+
+	proFile = defaultpro;
+	mapFile = defaultmap;
+
+	while ((c = getopt(argc, argv, "M:m:np:itvarVbs")) != -1) {
+		switch(c) {
+		case 'm':
+			mapFile = optarg;
+			break;
+		case 'n':
+			optNative++;
+			break;
+		case 'p':
+			proFile = optarg;
+			break;
+		case 'a':
+			optAll++;
+			break;
+		case 'b':
+			optBins++;
+			break;
+		case 's':
+			optSub++;
+			break;
+		case 'i':
+			optInfo++;
+			break;
+		case 'M':
+			mult = optarg;
+			break;
+		case 'r':
+			optReset++;
+			break;
+		case 'v':
+			optVerbose++;
+			break;
+		default:
+			bb_show_usage();
+		}
+	}
+
+	if (optReset || mult) {
+		int multiplier, fd, to_write;
+
+		/*
+		 * When writing the multiplier, if the length of the write is
+		 * not sizeof(int), the multiplier is not changed
+		 */
+		if (mult) {
+			multiplier = strtoul(mult, 0, 10);
+			to_write = sizeof(int);
+		} else {
+			multiplier = 0;
+			to_write = 1;	/* sth different from sizeof(int) */
+		}
+
+		fd = bb_xopen(defaultpro,O_WRONLY);
+		if (fd < 0)
+			bb_perror_msg_and_die(defaultpro);
+
+		if (write(fd, &multiplier, to_write) != to_write)
+			bb_perror_msg_and_die("error writing %s", defaultpro);
+
+		close(fd);
+		return EXIT_SUCCESS;
+	}
+
+	/*
+	 * Use an fd for the profiling buffer, to skip stdio overhead
+	 */
+	if (((proFd = bb_xopen(proFile,O_RDONLY)) < 0)
+	    || ((int)(len=lseek(proFd,0,SEEK_END)) < 0)
+	    || (lseek(proFd,0,SEEK_SET) < 0))
+		bb_perror_msg_and_die(proFile);
+
+	if (!(buf = xmalloc(len)))
+		bb_perror_nomsg_and_die();
+
+	if (read(proFd,buf,len) != len)
+		bb_perror_msg_and_die(proFile);
+
+	close(proFd);
+
+	if (!optNative) {
+		int entries = len/sizeof(*buf);
+		int big = 0,small = 0,i;
+		unsigned *p;
+
+		for (p = buf+1; p < buf+entries; p++) {
+			if (*p & ~0U << (sizeof(*buf)*4))
+				big++;
+			if (*p & ((1 << (sizeof(*buf)*4))-1))
+				small++;
+		}
+		if (big > small) {
+			fprintf(stderr,"Assuming reversed byte order. "
+				"Use -n to force native byte order.\n");
+			for (p = buf; p < buf+entries; p++)
+				for (i = 0; i < sizeof(*buf)/2; i++) {
+					unsigned char *b = (unsigned char *) p;
+					unsigned char tmp;
+
+					tmp = b[i];
+					b[i] = b[sizeof(*buf)-i-1];
+					b[sizeof(*buf)-i-1] = tmp;
+				}
+		}
+	}
+
+	step = buf[0];
+	if (optInfo) {
+		printf("Sampling_step: %i\n", step);
+		return EXIT_SUCCESS;
+	}
+
+	total = 0;
+
+	map = bb_xfopen(mapFile, "r");
+	if (map == NULL)
+		bb_perror_msg_and_die(mapFile);
+
+	while (fgets(mapline,S_LEN,map)) {
+		if (sscanf(mapline,"%llx %s %s",&fn_add,mode,fn_name) != 3)
+			bb_error_msg_and_die("%s(%i): wrong map line",
+					     mapFile, maplineno);
+
+		if (!strcmp(fn_name,"_stext")) /* only elf works like this */ {
+			add0 = fn_add;
+			break;
+		}
+		maplineno++;
+	}
+
+	if (!add0)
+		bb_error_msg_and_die("can't find \"_stext\" in %s\n", mapFile);
+
+	/*
+	 * Main loop.
+	 */
+	while (fgets(mapline,S_LEN,map)) {
+		unsigned int this = 0;
+
+		if (sscanf(mapline,"%llx %s %s",&next_add,mode,next_name) != 3)
+			bb_error_msg_and_die("%s(%i): wrong map line\n",
+					     mapFile, maplineno);
+
+		header_printed = 0;
+
+		/* ignore any LEADING (before a '[tT]' symbol is found)
+		   Absolute symbols */
+		if ((*mode == 'A' || *mode == '?') && total == 0) continue;
+		if (*mode != 'T' && *mode != 't' &&
+		    *mode != 'W' && *mode != 'w')
+			break;	/* only text is profiled */
+
+		if (indx >= len / sizeof(*buf))
+			bb_error_msg_and_die("profile address out of range. "
+					     "Wrong map file?");
+
+		while (indx < (next_add-add0)/step) {
+			if (optBins && (buf[indx] || optAll)) {
+				if (!header_printed) {
+					printf ("%s:\n", fn_name);
+					header_printed = 1;
+				}
+				printf ("\t%llx\t%u\n", (indx - 1)*step + add0, buf[indx]);
+			}
+			this += buf[indx++];
+		}
+		total += this;
+
+		if (optBins) {
+			if (optVerbose || this > 0)
+				printf ("  total\t\t\t\t%u\n", this);
+		} else if ((this || optAll) &&
+			   (fn_len = next_add-fn_add) != 0) {
+			if (optVerbose)
+				printf("%016llx %-40s %6i %8.4f\n", fn_add,
+				       fn_name,this,this/(double)fn_len);
+			else
+				printf("%6i %-40s %8.4f\n",
+				       this,fn_name,this/(double)fn_len);
+			if (optSub) {
+				unsigned long long scan;
+
+				for (scan = (fn_add-add0)/step + 1;
+				     scan < (next_add-add0)/step; scan++) {
+					unsigned long long addr;
+
+					addr = (scan - 1)*step + add0;
+					printf("\t%#llx\t%s+%#llx\t%u\n",
+					       addr, fn_name, addr - fn_add,
+					       buf[scan]);
+				}
+			}
+		}
+
+		fn_add = next_add;
+		strcpy(fn_name,next_name);
+
+		maplineno++;
+	}
+
+	/* clock ticks, out of kernel text - probably modules */
+	printf("%6i %s\n", buf[len/sizeof(*buf)-1], "*unknown*");
+
+	/* trailer */
+	if (optVerbose)
+		printf("%016x %-40s %6i %8.4f\n",
+		       0,"total",total,total/(double)(fn_add-add0));
+	else
+		printf("%6i %-40s %8.4f\n",
+		       total,"total",total/(double)(fn_add-add0));
+
+	fclose(map);
+	free(buf);
+
+	return EXIT_SUCCESS;
+}