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
  35 #include "builtin.h"
  36
  37 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
  38
  39 struct cmd_struct {
  40         const char *name;
  41         int (*fn)(int, const char **);
  42         const char *help;
  43 };
  44
  45 static const char objtool_usage_string[] =
  46         "objtool [OPTIONS] COMMAND [ARGS]";
  47
  48 static struct cmd_struct objtool_cmds[] = {
  49         {"check",       cmd_check,      "Perform stack metadata validation on an object file" },
  50 };
  51
  52 bool help;
  53
  54 static void cmd_usage(void)
  55 {
  56         unsigned int i, longest = 0;
  57
  58         printf("\n usage: %s\n\n", objtool_usage_string);
  59
  60         for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
  61                 if (longest < strlen(objtool_cmds[i].name))
  62                         longest = strlen(objtool_cmds[i].name);
  63         }
  64
  65         puts(" Commands:");
  66         for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
  67                 printf("   %-*s   ", longest, objtool_cmds[i].name);
  68                 puts(objtool_cmds[i].help);
  69         }
  70
  71         printf("\n");
  72
  73         exit(1);
  74 }
  75
  76 static void handle_options(int *argc, const char ***argv)
  77 {
  78         while (*argc > 0) {
  79                 const char *cmd = (*argv)[0];
  80
  81                 if (cmd[0] != '-')
  82                         break;
  83
  84                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "-h")) {
  85                         help = true;
  86                         break;
  87                 } else {
  88                         fprintf(stderr, "Unknown option: %s\n", cmd);
  89                         fprintf(stderr, "\n Usage: %s\n",
  90                                 objtool_usage_string);
  91                         exit(1);
  92                 }
  93
  94                 (*argv)++;
  95                 (*argc)--;
  96         }
  97 }
  98
  99 static void handle_internal_command(int argc, const char **argv)
 100 {
 101         const char *cmd = argv[0];
 102         unsigned int i, ret;
 103
 104         for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) {
 105                 struct cmd_struct *p = objtool_cmds+i;
 106
 107                 if (strcmp(p->name, cmd))
 108                         continue;
 109
 110                 ret = p->fn(argc, argv);
 111
 112                 exit(ret);
 113         }
 114
 115         cmd_usage();
 116 }
 117
 118 int main(int argc, const char **argv)
 119 {
 120         static const char *UNUSED = "OBJTOOL_NOT_IMPLEMENTED";
 121
 122         /* libsubcmd init */
 123         exec_cmd_init("objtool", UNUSED, UNUSED, UNUSED);
 124         pager_init(UNUSED);
 125
 126         argv++;
 127         argc--;
 128         handle_options(&argc, &argv);
 129
 130         if (!argc || help)
 131                 cmd_usage();
 132
 133         handle_internal_command(argc, argv);
 134
 135         return 0;
 136 }