src/bin/lttng-sessiond/modprobe.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License as published by the Free
   6  * Software Foundation; only version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA  02111-1307, USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <sys/wait.h>
  22
  23 #include <common/common.h>
  24
  25 #include "modprobe.h"
  26 #include "kern-modules.h"
  27
  28 /* MUST be loaded first */
  29 const struct kern_modules_param kern_modules_control[] = {
  30         { "lttng-tracer", 1 },
  31 };
  32
  33 /* LTTng kernel tracer modules list */
  34 const struct kern_modules_param kern_modules_list[] = {
  35         { "lttng-ftrace", 0 },
  36         { "lttng-kprobes", 0 },
  37         { "lttng-kretprobes", 0 },
  38         { "lttng-lib-ring-buffer", 1 },
  39         { "lttng-ring-buffer-client-discard", 1 },
  40         { "lttng-ring-buffer-client-overwrite", 1 },
  41         { "lttng-ring-buffer-metadata-client", 1 },
  42         { "lttng-ring-buffer-client-mmap-discard", 1 },
  43         { "lttng-ring-buffer-client-mmap-overwrite", 1 },
  44         { "lttng-ring-buffer-metadata-mmap-client", 1 },
  45         { "lttng-probe-lttng", 1 },
  46         { "lttng-types", 0 },
  47         { "lttng-probe-block", 0 },
  48         { "lttng-probe-irq", 0 },
  49         { "lttng-probe-kvm", 0 },
  50         { "lttng-probe-sched", 0 },
  51         { "lttng-probe-signal", 0 },
  52         { "lttng-probe-statedump", 0 },
  53 };
  54
  55 /*
  56  * Remove control kernel module(s) in reverse load order.
  57  */
  58 void modprobe_remove_lttng_control(void)
  59 {
  60         int ret = 0, i;
  61         char modprobe[256];
  62
  63         for (i = ARRAY_SIZE(kern_modules_control) - 1; i >= 0; i--) {
  64                 ret = snprintf(modprobe, sizeof(modprobe),
  65                                 "/sbin/modprobe -r -q %s",
  66                                 kern_modules_control[i].name);
  67                 if (ret < 0) {
  68                         PERROR("snprintf modprobe -r");
  69                         goto error;
  70                 }
  71                 modprobe[sizeof(modprobe) - 1] = '\0';
  72                 ret = system(modprobe);
  73                 if (ret == -1) {
  74                         ERR("Unable to launch modprobe -r for module %s",
  75                                         kern_modules_control[i].name);
  76                 } else if (kern_modules_control[i].required
  77                                 && WEXITSTATUS(ret) != 0) {
  78                         ERR("Unable to remove module %s",
  79                                         kern_modules_control[i].name);
  80                 } else {
  81                         DBG("Modprobe removal successful %s",
  82                                         kern_modules_control[i].name);
  83                 }
  84         }
  85
  86 error:
  87         return;
  88 }
  89
  90 /*
  91  * Remove data kernel modules in reverse load order.
  92  */
  93 void modprobe_remove_lttng_data(void)
  94 {
  95         int ret = 0, i;
  96         char modprobe[256];
  97
  98         for (i = ARRAY_SIZE(kern_modules_list) - 1; i >= 0; i--) {
  99                 ret = snprintf(modprobe, sizeof(modprobe),
 100                                 "/sbin/modprobe -r -q %s",
 101                                 kern_modules_list[i].name);
 102                 if (ret < 0) {
 103                         perror("snprintf modprobe -r");
 104                         goto error;
 105                 }
 106                 modprobe[sizeof(modprobe) - 1] = '\0';
 107                 ret = system(modprobe);
 108                 if (ret == -1) {
 109                         ERR("Unable to launch modprobe -r for module %s",
 110                                         kern_modules_list[i].name);
 111                 } else if (kern_modules_list[i].required
 112                                 && WEXITSTATUS(ret) != 0) {
 113                         ERR("Unable to remove module %s",
 114                                         kern_modules_list[i].name);
 115                 } else {
 116                         DBG("Modprobe removal successful %s",
 117                                         kern_modules_list[i].name);
 118                 }
 119         }
 120
 121 error:
 122         return;
 123 }
 124
 125 /*
 126  * Remove all kernel modules in reverse order.
 127  */
 128 void modprobe_remove_lttng_all(void)
 129 {
 130         modprobe_remove_lttng_data();
 131         modprobe_remove_lttng_control();
 132 }
 133
 134 /*
 135  * Load control kernel module(s).
 136  */
 137 int modprobe_lttng_control(void)
 138 {
 139         int ret = 0, i;
 140         char modprobe[256];
 141
 142         for (i = 0; i < ARRAY_SIZE(kern_modules_control); i++) {
 143                 ret = snprintf(modprobe, sizeof(modprobe),
 144                                 "/sbin/modprobe %s%s",
 145                                 kern_modules_control[i].required ? "" : "-q ",
 146                                 kern_modules_control[i].name);
 147                 if (ret < 0) {
 148                         PERROR("snprintf modprobe");
 149                         goto error;
 150                 }
 151                 modprobe[sizeof(modprobe) - 1] = '\0';
 152                 ret = system(modprobe);
 153                 if (ret == -1) {
 154                         ERR("Unable to launch modprobe for module %s",
 155                                         kern_modules_control[i].name);
 156                 } else if (kern_modules_control[i].required
 157                                 && WEXITSTATUS(ret) != 0) {
 158                         ERR("Unable to load module %s",
 159                                         kern_modules_control[i].name);
 160                 } else {
 161                         DBG("Modprobe successfully %s",
 162                                         kern_modules_control[i].name);
 163                 }
 164         }
 165
 166 error:
 167         return ret;
 168 }
 169
 170 /*
 171  * Load data kernel module(s).
 172  */
 173 int modprobe_lttng_data(void)
 174 {
 175         int ret = 0, i;
 176         char modprobe[256];
 177
 178         for (i = 0; i < ARRAY_SIZE(kern_modules_list); i++) {
 179                 ret = snprintf(modprobe, sizeof(modprobe),
 180                                 "/sbin/modprobe %s%s",
 181                                 kern_modules_list[i].required ? "" : "-q ",
 182                                 kern_modules_list[i].name);
 183                 if (ret < 0) {
 184                         perror("snprintf modprobe");
 185                         goto error;
 186                 }
 187                 modprobe[sizeof(modprobe) - 1] = '\0';
 188                 ret = system(modprobe);
 189                 if (ret == -1) {
 190                         ERR("Unable to launch modprobe for module %s",
 191                                         kern_modules_list[i].name);
 192                 } else if (kern_modules_list[i].required
 193                                 && WEXITSTATUS(ret) != 0) {
 194                         ERR("Unable to load module %s",
 195                                         kern_modules_list[i].name);
 196                 } else {
 197                         DBG("Modprobe successfully %s",
 198                                         kern_modules_list[i].name);
 199                 }
 200         }
 201
 202 error:
 203         return ret;
 204 }
 205
 206 /*
 207  * Load all lttng kernel modules.
 208  */
 209 int modprobe_lttng_all(void)
 210 {
 211         int ret;
 212
 213         ret = modprobe_lttng_control();
 214         if (ret < 0) {
 215                 goto error;
 216         }
 217
 218         ret = modprobe_lttng_data();
 219         if (ret < 0) {
 220                 goto error;
 221         }
 222
 223 error:
 224         return ret;
 225 }