util-linux/readprofile.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * readprofile.c - used to read /proc/profile
   4  *
   5  * Copyright (C) 1994,1996 Alessandro Rubini (rubini@ipvvis.unipv.it)
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8  */
   9
  10 /*
  11  * 1999-02-22 Arkadiusz Mickiewicz <misiek@pld.ORG.PL>
  12  * - added Native Language Support
  13  * 1999-09-01 Stephane Eranian <eranian@cello.hpl.hp.com>
  14  * - 64bit clean patch
  15  * 3Feb2001 Andrew Morton <andrewm@uow.edu.au>
  16  * - -M option to write profile multiplier.
  17  * 2001-11-07 Werner Almesberger <wa@almesberger.net>
  18  * - byte order auto-detection and -n option
  19  * 2001-11-09 Werner Almesberger <wa@almesberger.net>
  20  * - skip step size (index 0)
  21  * 2002-03-09 John Levon <moz@compsoc.man.ac.uk>
  22  * - make maplineno do something
  23  * 2002-11-28 Mads Martin Joergensen +
  24  * - also try /boot/System.map-`uname -r`
  25  * 2003-04-09 Werner Almesberger <wa@almesberger.net>
  26  * - fixed off-by eight error and improved heuristics in byte order detection
  27  * 2003-08-12 Nikita Danilov <Nikita@Namesys.COM>
  28  * - added -s option; example of use:
  29  * "readprofile -s -m /boot/System.map-test | grep __d_lookup | sort -n -k3"
  30  *
  31  * Taken from util-linux and adapted for busybox by
  32  * Paul Mundt <lethal@linux-sh.org>.
  33  */
  34 //config:config READPROFILE
  35 //config:       bool "readprofile (7.1 kb)"
  36 //config:       default y
  37 //config:       #select PLATFORM_LINUX
  38 //config:       help
  39 //config:       This allows you to parse /proc/profile for basic profiling.
  40
  41 //applet:IF_READPROFILE(APPLET(readprofile, BB_DIR_USR_SBIN, BB_SUID_DROP))
  42
  43 //kbuild:lib-$(CONFIG_READPROFILE) += readprofile.o
  44
  45 //usage:#define readprofile_trivial_usage
  46 //usage:       "[OPTIONS]"
  47 //usage:#define readprofile_full_usage "\n\n"
  48 //usage:       "        -m mapfile      (Default: /boot/System.map)"
  49 //usage:     "\n        -p profile      (Default: /proc/profile)"
  50 //usage:     "\n        -M NUM          Set the profiling multiplier to NUM"
  51 //usage:     "\n        -i              Print only info about the sampling step"
  52 //usage:     "\n        -v              Verbose"
  53 //usage:     "\n        -a              Print all symbols, even if count is 0"
  54 //usage:     "\n        -b              Print individual histogram-bin counts"
  55 //usage:     "\n        -s              Print individual counters within functions"
  56 //usage:     "\n        -r              Reset all the counters (root only)"
  57 //usage:     "\n        -n              Disable byte order auto-detection"
  58
  59 #include "libbb.h"
  60 #include <sys/utsname.h>
  61
  62 #define S_LEN 128
  63
  64 int readprofile_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  65 int readprofile_main(int argc UNUSED_PARAM, char **argv)
  66 {
  67         FILE *map;
  68         const char *mapFile, *proFile;
  69         unsigned long indx;
  70         size_t len;
  71         uint64_t add0;
  72         unsigned int step;
  73         unsigned int *buf, total, fn_len;
  74         unsigned long long fn_add, next_add;     /* current and next address */
  75         char fn_name[S_LEN], next_name[S_LEN];   /* current and next name */
  76         char mapline[S_LEN];
  77         char mode[8];
  78         int maplineno;
  79         int multiplier;
  80         unsigned opt;
  81         enum {
  82                 OPT_M = (1 << 0),
  83                 OPT_m = (1 << 1),
  84                 OPT_p = (1 << 2),
  85                 OPT_n = (1 << 3),
  86                 OPT_a = (1 << 4),
  87                 OPT_b = (1 << 5),
  88                 OPT_s = (1 << 6),
  89                 OPT_i = (1 << 7),
  90                 OPT_r = (1 << 8),
  91                 OPT_v = (1 << 9),
  92         };
  93 #define optMult    (opt & OPT_M)
  94 #define optNative  (opt & OPT_n)
  95 #define optAll     (opt & OPT_a)
  96 #define optBins    (opt & OPT_b)
  97 #define optSub     (opt & OPT_s)
  98 #define optInfo    (opt & OPT_i)
  99 #define optReset   (opt & OPT_r)
 100 #define optVerbose (opt & OPT_v)
 101
 102 #define next (current^1)
 103
 104         proFile = "/proc/profile";
 105         mapFile = "/boot/System.map";
 106         multiplier = 0;
 107
 108         opt = getopt32(argv, "M:+m:p:nabsirv", &multiplier, &mapFile, &proFile);
 109
 110         if (opt & (OPT_M|OPT_r)) { /* mult or reset, or both */
 111                 int fd, to_write;
 112
 113                 /*
 114                  * When writing the multiplier, if the length of the write is
 115                  * not sizeof(int), the multiplier is not changed
 116                  */
 117                 to_write = sizeof(int);
 118                 if (!optMult)
 119                         to_write = 1;  /* sth different from sizeof(int) */
 120
 121                 fd = xopen("/proc/profile", O_WRONLY);
 122                 xwrite(fd, &multiplier, to_write);
 123                 close(fd);
 124                 return EXIT_SUCCESS;
 125         }
 126
 127         /*
 128          * Use an fd for the profiling buffer, to skip stdio overhead
 129          */
 130         len = MAXINT(ssize_t);
 131         buf = xmalloc_xopen_read_close(proFile, &len);
 132         len /= sizeof(*buf);
 133
 134         if (!optNative) {
 135                 int big = 0, small = 0;
 136                 unsigned *p;
 137
 138                 for (p = buf+1; p < buf+len; p++) {
 139                         if (*p & ~0U << (sizeof(*buf)*4))
 140                                 big++;
 141                         if (*p & ((1 << (sizeof(*buf)*4))-1))
 142                                 small++;
 143                 }
 144                 if (big > small) {
 145                         bb_error_msg("assuming reversed byte order, "
 146                                 "use -n to force native byte order");
 147                         BUILD_BUG_ON(sizeof(*p) > 8);
 148                         for (p = buf; p < buf+len; p++) {
 149                                 if (sizeof(*p) == 2)
 150                                         *p = bswap_16(*p);
 151                                 if (sizeof(*p) == 4)
 152                                         *p = bswap_32(*p);
 153                                 if (sizeof(*p) == 8)
 154                                         *p = bb_bswap_64(*p);
 155                         }
 156                 }
 157         }
 158
 159         step = buf[0];
 160         if (optInfo) {
 161                 printf("Sampling_step: %u\n", step);
 162                 return EXIT_SUCCESS;
 163         }
 164
 165         map = xfopen_for_read(mapFile);
 166         add0 = 0;
 167         maplineno = 1;
 168         while (fgets(mapline, S_LEN, map)) {
 169                 if (sscanf(mapline, "%llx %s %s", &fn_add, mode, fn_name) != 3)
 170                         bb_error_msg_and_die("%s(%i): wrong map line",
 171                                         mapFile, maplineno);
 172
 173                 if (strcmp(fn_name, "_stext") == 0) /* only elf works like this */ {
 174                         add0 = fn_add;
 175                         break;
 176                 }
 177                 maplineno++;
 178         }
 179
 180         if (!add0)
 181                 bb_error_msg_and_die("can't find \"_stext\" in %s", mapFile);
 182
 183         /*
 184          * Main loop.
 185          */
 186         total = 0;
 187         indx = 1;
 188         while (fgets(mapline, S_LEN, map)) {
 189                 bool header_printed;
 190                 unsigned int this;
 191
 192                 if (sscanf(mapline, "%llx %s %s", &next_add, mode, next_name) != 3)
 193                         bb_error_msg_and_die("%s(%i): wrong map line",
 194                                         mapFile, maplineno);
 195
 196                 header_printed = 0;
 197
 198                 /* ignore any LEADING (before a '[tT]' symbol is found)
 199                    Absolute symbols */
 200                 if ((mode[0] == 'A' || mode[0] == '?') && total == 0)
 201                         continue;
 202                 if ((mode[0]|0x20) != 't' && (mode[0]|0x20) != 'w') {
 203                         break;  /* only text is profiled */
 204                 }
 205
 206                 if (indx >= len)
 207                         bb_error_msg_and_die("profile address out of range. "
 208                                         "Wrong map file?");
 209
 210                 this = 0;
 211                 while (indx < (next_add-add0)/step) {
 212                         if (optBins && (buf[indx] || optAll)) {
 213                                 if (!header_printed) {
 214                                         printf("%s:\n", fn_name);
 215                                         header_printed = 1;
 216                                 }
 217                                 printf("\t%"PRIx64"\t%u\n", (indx - 1)*step + add0, buf[indx]);
 218                         }
 219                         this += buf[indx++];
 220                 }
 221                 total += this;
 222
 223                 if (optBins) {
 224                         if (optVerbose || this > 0)
 225                                 printf("  total\t\t\t\t%u\n", this);
 226                 } else
 227                 if ((this || optAll)
 228                  && (fn_len = next_add-fn_add) != 0
 229                 ) {
 230                         if (optVerbose)
 231                                 printf("%016llx %-40s %6u %8.4f\n", fn_add,
 232                                         fn_name, this, this/(double)fn_len);
 233                         else
 234                                 printf("%6u %-40s %8.4f\n",
 235                                         this, fn_name, this/(double)fn_len);
 236                         if (optSub) {
 237                                 unsigned long long scan;
 238
 239                                 for (scan = (fn_add-add0)/step + 1;
 240                                      scan < (next_add-add0)/step; scan++) {
 241                                         unsigned long long addr;
 242
 243                                         addr = (scan - 1)*step + add0;
 244                                         printf("\t%#llx\t%s+%#llx\t%u\n",
 245                                                 addr, fn_name, addr - fn_add,
 246                                                 buf[scan]);
 247                                 }
 248                         }
 249                 }
 250
 251                 fn_add = next_add;
 252                 strcpy(fn_name, next_name);
 253
 254                 maplineno++;
 255         }
 256
 257         /* clock ticks, out of kernel text - probably modules */
 258         printf("%6u *unknown*\n", buf[len-1]);
 259
 260         /* trailer */
 261         if (optVerbose)
 262                 printf("%016x %-40s %6u %8.4f\n",
 263                         0, "total", total, total/(double)(fn_add-add0));
 264         else
 265                 printf("%6u %-40s %8.4f\n",
 266                         total, "total", total/(double)(fn_add-add0));
 267
 268         if (ENABLE_FEATURE_CLEAN_UP) {
 269                 fclose(map);
 270                 free(buf);
 271         }
 272
 273         return EXIT_SUCCESS;
 274 }