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         { "ltt-relay", 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         { "lib-ring-buffer", 1 },
  39         { "ltt-ring-buffer-client-discard", 1 },
  40         { "ltt-ring-buffer-client-overwrite", 1 },
  41         { "ltt-ring-buffer-metadata-client", 1 },
  42         { "ltt-ring-buffer-client-mmap-discard", 1 },
  43         { "ltt-ring-buffer-client-mmap-overwrite", 1 },
  44         { "ltt-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 };
  52
  53 /*
  54  * Remove control kernel module(s) in reverse load order.
  55  */
  56 void modprobe_remove_lttng_control(void)
  57 {
  58         int ret = 0, i;
  59         char modprobe[256];
  60
  61         for (i = ARRAY_SIZE(kern_modules_control) - 1; i >= 0; i--) {
  62                 ret = snprintf(modprobe, sizeof(modprobe),
  63                                 "/sbin/modprobe -r -q %s",
  64                                 kern_modules_control[i].name);
  65                 if (ret < 0) {
  66                         PERROR("snprintf modprobe -r");
  67                         goto error;
  68                 }
  69                 modprobe[sizeof(modprobe) - 1] = '\0';
  70                 ret = system(modprobe);
  71                 if (ret == -1) {
  72                         ERR("Unable to launch modprobe -r for module %s",
  73                                         kern_modules_control[i].name);
  74                 } else if (kern_modules_control[i].required
  75                                 && WEXITSTATUS(ret) != 0) {
  76                         ERR("Unable to remove module %s",
  77                                         kern_modules_control[i].name);
  78                 } else {
  79                         DBG("Modprobe removal successful %s",
  80                                         kern_modules_control[i].name);
  81                 }
  82         }
  83
  84 error:
  85         return;
  86 }
  87
  88 /*
  89  * Remove data kernel modules in reverse load order.
  90  */
  91 void modprobe_remove_lttng_data(void)
  92 {
  93         int ret = 0, i;
  94         char modprobe[256];
  95
  96         for (i = ARRAY_SIZE(kern_modules_list) - 1; i >= 0; i--) {
  97                 ret = snprintf(modprobe, sizeof(modprobe),
  98                                 "/sbin/modprobe -r -q %s",
  99                                 kern_modules_list[i].name);
 100                 if (ret < 0) {
 101                         perror("snprintf modprobe -r");
 102                         goto error;
 103                 }
 104                 modprobe[sizeof(modprobe) - 1] = '\0';
 105                 ret = system(modprobe);
 106                 if (ret == -1) {
 107                         ERR("Unable to launch modprobe -r for module %s",
 108                                         kern_modules_list[i].name);
 109                 } else if (kern_modules_list[i].required
 110                                 && WEXITSTATUS(ret) != 0) {
 111                         ERR("Unable to remove module %s",
 112                                         kern_modules_list[i].name);
 113                 } else {
 114                         DBG("Modprobe removal successful %s",
 115                                         kern_modules_list[i].name);
 116                 }
 117         }
 118
 119 error:
 120         return;
 121 }
 122
 123 /*
 124  * Remove all kernel modules in reverse order.
 125  */
 126 void modprobe_remove_lttng_all(void)
 127 {
 128         modprobe_remove_lttng_data();
 129         modprobe_remove_lttng_control();
 130 }
 131
 132 /*
 133  * Load control kernel module(s).
 134  */
 135 int modprobe_lttng_control(void)
 136 {
 137         int ret = 0, i;
 138         char modprobe[256];
 139
 140         for (i = 0; i < ARRAY_SIZE(kern_modules_control); i++) {
 141                 ret = snprintf(modprobe, sizeof(modprobe),
 142                                 "/sbin/modprobe %s%s",
 143                                 kern_modules_control[i].required ? "" : "-q ",
 144                                 kern_modules_control[i].name);
 145                 if (ret < 0) {
 146                         PERROR("snprintf modprobe");
 147                         goto error;
 148                 }
 149                 modprobe[sizeof(modprobe) - 1] = '\0';
 150                 ret = system(modprobe);
 151                 if (ret == -1) {
 152                         ERR("Unable to launch modprobe for module %s",
 153                                         kern_modules_control[i].name);
 154                 } else if (kern_modules_control[i].required
 155                                 && WEXITSTATUS(ret) != 0) {
 156                         ERR("Unable to load module %s",
 157                                         kern_modules_control[i].name);
 158                 } else {
 159                         DBG("Modprobe successfully %s",
 160                                         kern_modules_control[i].name);
 161                 }
 162         }
 163
 164 error:
 165         return ret;
 166 }
 167
 168 /*
 169  * Load data kernel module(s).
 170  */
 171 int modprobe_lttng_data(void)
 172 {
 173         int ret = 0, i;
 174         char modprobe[256];
 175
 176         for (i = 0; i < ARRAY_SIZE(kern_modules_list); i++) {
 177                 ret = snprintf(modprobe, sizeof(modprobe),
 178                                 "/sbin/modprobe %s%s",
 179                                 kern_modules_list[i].required ? "" : "-q ",
 180                                 kern_modules_list[i].name);
 181                 if (ret < 0) {
 182                         perror("snprintf modprobe");
 183                         goto error;
 184                 }
 185                 modprobe[sizeof(modprobe) - 1] = '\0';
 186                 ret = system(modprobe);
 187                 if (ret == -1) {
 188                         ERR("Unable to launch modprobe for module %s",
 189                                         kern_modules_list[i].name);
 190                 } else if (kern_modules_list[i].required
 191                                 && WEXITSTATUS(ret) != 0) {
 192                         ERR("Unable to load module %s",
 193                                         kern_modules_list[i].name);
 194                 } else {
 195                         DBG("Modprobe successfully %s",
 196                                         kern_modules_list[i].name);
 197                 }
 198         }
 199
 200 error:
 201         return ret;
 202 }
 203
 204 /*
 205  * Load all lttng kernel modules.
 206  */
 207 int modprobe_lttng_all(void)
 208 {
 209         int ret;
 210
 211         ret = modprobe_lttng_control();
 212         if (ret < 0) {
 213                 goto error;
 214         }
 215
 216         ret = modprobe_lttng_data();
 217         if (ret < 0) {
 218                 goto error;
 219         }
 220
 221 error:
 222         return ret;
 223 }