LXR busybox/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
  64int readprofile_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  65int 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}
 275