tools/remove.c

   1 /*
   2  * kmod-remove - remove modules from the kernel.
   3  *
   4  * Copyright (C) 2015 Intel Corporation. All rights reserved.
   5  * Copyright (C) 2011-2013  ProFUSION embedded systems
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <errno.h>
  22 #include <getopt.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include <libkmod/libkmod.h>
  27
  28 #include "kmod.h"
  29
  30 static const char cmdopts_s[] = "h";
  31 static const struct option cmdopts[] = {
  32         {"help", no_argument, 0, 'h'},
  33         { }
  34 };
  35
  36 static void help(void)
  37 {
  38         printf("Usage:\n"
  39                "\t%s remove [options] module\n"
  40                "Options:\n"
  41                "\t-h, --help        show this help\n",
  42                program_invocation_short_name);
  43 }
  44
  45 static int check_module_inuse(struct kmod_module *mod) {
  46         struct kmod_list *holders;
  47         int state, ret;
  48
  49         state = kmod_module_get_initstate(mod);
  50
  51         if (state == KMOD_MODULE_BUILTIN) {
  52                 ERR("Module %s is builtin.\n", kmod_module_get_name(mod));
  53                 return -ENOENT;
  54         } else if (state < 0) {
  55                 ERR("Module %s is not currently loaded\n",
  56                                 kmod_module_get_name(mod));
  57                 return -ENOENT;
  58         }
  59
  60         holders = kmod_module_get_holders(mod);
  61         if (holders != NULL) {
  62                 struct kmod_list *itr;
  63
  64                 ERR("Module %s is in use by:", kmod_module_get_name(mod));
  65
  66                 kmod_list_foreach(itr, holders) {
  67                         struct kmod_module *hm = kmod_module_get_module(itr);
  68                         fprintf(stderr, " %s", kmod_module_get_name(hm));
  69                         kmod_module_unref(hm);
  70                 }
  71                 fputc('\n', stderr);
  72
  73                 kmod_module_unref_list(holders);
  74                 return -EBUSY;
  75         }
  76
  77         ret = kmod_module_get_refcnt(mod);
  78         if (ret > 0) {
  79                 ERR("Module %s is in use\n", kmod_module_get_name(mod));
  80                 return -EBUSY;
  81         } else if (ret == -ENOENT) {
  82                 ERR("Module unloading is not supported\n");
  83         }
  84
  85         return ret;
  86 }
  87
  88 static int do_remove(int argc, char *argv[])
  89 {
  90         struct kmod_ctx *ctx;
  91         struct kmod_module *mod;
  92         const char *name;
  93         int err, r = EXIT_SUCCESS;
  94
  95         for (;;) {
  96                 int c, idx =0;
  97                 c = getopt_long(argc, argv, cmdopts_s, cmdopts, &idx);
  98                 if (c == -1)
  99                         break;
 100                 switch (c) {
 101                 case 'h':
 102                         help();
 103                         return EXIT_SUCCESS;
 104
 105                 default:
 106                         ERR("Unexpected getopt_long() value '%c'.\n", c);
 107                         return EXIT_FAILURE;
 108                 }
 109         }
 110
 111         if (optind >= argc) {
 112                 ERR("Missing module name\n");
 113                 return EXIT_FAILURE;
 114         }
 115
 116         ctx = kmod_new(NULL, NULL);
 117         if (!ctx) {
 118                 ERR("kmod_new() failed!\n");
 119                 return EXIT_FAILURE;
 120         }
 121
 122         name = argv[optind];
 123         err = kmod_module_new_from_name(ctx, name, &mod);
 124         if (err < 0) {
 125                 ERR("Could not remove module %s: %s\n", name, strerror(-err));
 126                 goto end;
 127         }
 128
 129         err = check_module_inuse(mod);
 130         if (err < 0)
 131                 goto unref;
 132
 133         err = kmod_module_remove_module(mod, 0);
 134         if (err < 0)
 135                 goto unref;
 136
 137 unref:
 138         kmod_module_unref(mod);
 139
 140 end:
 141         kmod_unref(ctx);
 142         if (err < 0) {
 143                 r = EXIT_FAILURE;
 144                 ERR("Could not remove module %s: %s\n", name, strerror(-err));
 145         }
 146         return r;
 147 }
 148
 149 const struct kmod_cmd kmod_cmd_remove = {
 150         .name = "remove",
 151         .cmd = do_remove,
 152         .help = "remove module from kernel",
 153 };