tools/objtool/objtool.c

   1 /*
   2  * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /*
  19  * objtool:
  20  *
  21  * The 'check' subcmd analyzes every .o file and ensures the validity of its
  22  * stack trace metadata.  It enforces a set of rules on asm code and C inline
  23  * assembly code so that stack traces can be reliable.
  24  *
  25  * For more information, see tools/objtool/Documentation/stack-validation.txt.
  26  */
  27
  28 #include <stdio.h>
  29 #include <stdbool.h>
  30 #include <string.h>
  31 #include <stdlib.h>
  32 #include <subcmd/exec-cmd.h>
  33 #include <subcmd/pager.h>
  34 #include <linux/kernel.h>
  35
  36 #include "builtin.h"
  37
  38 struct cmd_struct {
  39         const char *name;
  40         int (*fn)(int, const char **);
  41         const char *help;
  42 };
  43
  44 static const char objtool_usage_string[] =
  45         "objtool [OPTIONS] COMMAND [ARGS]";
  46
  47 static struct cmd_struct objtool_cmds[] = {
  48         {"check",       cmd_check,      "Perform stack metadata validation on an object file" },
  49 };
  50
  51 bool help;
  52
  53 static void cmd_usage(void)
  54 {
  55         unsigned int i, longest = 0;
  56
  57         printf("\n usage: %s\n\n", objtool_usage_string);
  58
  59         for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
  60                 if (longest < strlen(objtool_cmds[i].name))
  61                         longest = strlen(objtool_cmds[i].name);
  62         }
  63
  64         puts(" Commands:");
  65         for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
  66                 printf("   %-*s   ", longest, objtool_cmds[i].name);
  67                 puts(objtool_cmds[i].help);
  68         }
  69
  70         printf("\n");
  71
  72         exit(1);
  73 }
  74
  75 static void handle_options(int *argc, const char ***argv)
  76 {
  77         while (*argc > 0) {
  78                 const char *cmd = (*argv)[0];
  79
  80                 if (cmd[0] != '-')
  81                         break;
  82
  83                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "-h")) {
  84                         help = true;
  85                         break;
  86                 } else {
  87                         fprintf(stderr, "Unknown option: %s\n", cmd);
  88                         fprintf(stderr, "\n Usage: %s\n",
  89                                 objtool_usage_string);
  90                         exit(1);
  91                 }
  92
  93                 (*argv)++;
  94                 (*argc)--;
  95         }
  96 }
  97
  98 static void handle_internal_command(int argc, const char **argv)
  99 {
 100         const char *cmd = argv[0];
 101         unsigned int i, ret;
 102
 103         for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
 104                 struct cmd_struct *p = objtool_cmds+i;
 105
 106                 if (strcmp(p->name, cmd))
 107                         continue;
 108
 109                 ret = p->fn(argc, argv);
 110
 111                 exit(ret);
 112         }
 113
 114         cmd_usage();
 115 }
 116
 117 int main(int argc, const char **argv)
 118 {
 119         static const char *UNUSED = "OBJTOOL_NOT_IMPLEMENTED";
 120
 121         /* libsubcmd init */
 122         exec_cmd_init("objtool", UNUSED, UNUSED, UNUSED);
 123         pager_init(UNUSED);
 124
 125         argv++;
 126         argc--;
 127         handle_options(&argc, &argv);
 128
 129         if (!argc || help)
 130                 cmd_usage();
 131
 132         handle_internal_command(argc, argv);
 133
 134         return 0;
 135 }