tools/objtool/builtin-check.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2015-2017 Josh Poimboeuf <jpoimboe@redhat.com>
   4  */
   5
   6 /*
   7  * objtool check:
   8  *
   9  * This command analyzes every .o file and ensures the validity of its stack
  10  * trace metadata.  It enforces a set of rules on asm code and C inline
  11  * assembly code so that stack traces can be reliable.
  12  *
  13  * For more information, see tools/objtool/Documentation/stack-validation.txt.
  14  */
  15
  16 #include <subcmd/parse-options.h>
  17 #include <string.h>
  18 #include "builtin.h"
  19 #include "objtool.h"
  20
  21 bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, validate_dup, vmlinux;
  22
  23 static const char * const check_usage[] = {
  24         "objtool check [<options>] file.o",
  25         NULL,
  26 };
  27
  28 const struct option check_options[] = {
  29         OPT_BOOLEAN('f', "no-fp", &no_fp, "Skip frame pointer validation"),
  30         OPT_BOOLEAN('u', "no-unreachable", &no_unreachable, "Skip 'unreachable instruction' warnings"),
  31         OPT_BOOLEAN('r', "retpoline", &retpoline, "Validate retpoline assumptions"),
  32         OPT_BOOLEAN('m', "module", &module, "Indicates the object will be part of a kernel module"),
  33         OPT_BOOLEAN('b', "backtrace", &backtrace, "unwind on error"),
  34         OPT_BOOLEAN('a', "uaccess", &uaccess, "enable uaccess checking"),
  35         OPT_BOOLEAN('s', "stats", &stats, "print statistics"),
  36         OPT_BOOLEAN('d', "duplicate", &validate_dup, "duplicate validation for vmlinux.o"),
  37         OPT_BOOLEAN('l', "vmlinux", &vmlinux, "vmlinux.o validation"),
  38         OPT_END(),
  39 };
  40
  41 int cmd_check(int argc, const char **argv)
  42 {
  43         const char *objname, *s;
  44         struct objtool_file *file;
  45         int ret;
  46
  47         argc = parse_options(argc, argv, check_options, check_usage, 0);
  48
  49         if (argc != 1)
  50                 usage_with_options(check_usage, check_options);
  51
  52         objname = argv[0];
  53
  54         s = strstr(objname, "vmlinux.o");
  55         if (s && !s[9])
  56                 vmlinux = true;
  57
  58         file = objtool_open_read(objname);
  59         if (!file)
  60                 return 1;
  61
  62         ret = check(file);
  63         if (ret)
  64                 return ret;
  65
  66         if (file->elf->changed)
  67                 return elf_write(file->elf);
  68
  69         return 0;
  70 }