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         { "lttng-probe-timer", 0 },
  54 };
  55
  56 /*
  57  * Remove control kernel module(s) in reverse load order.
  58  */
  59 void modprobe_remove_lttng_control(void)
  60 {
  61         int ret = 0, i;
  62         char modprobe[256];
  63
  64         for (i = ARRAY_SIZE(kern_modules_control) - 1; i >= 0; i--) {
  65                 ret = snprintf(modprobe, sizeof(modprobe),
  66                                 "/sbin/modprobe -r -q %s",
  67                                 kern_modules_control[i].name);
  68                 if (ret < 0) {
  69                         PERROR("snprintf modprobe -r");
  70                         goto error;
  71                 }
  72                 modprobe[sizeof(modprobe) - 1] = '\0';
  73                 ret = system(modprobe);
  74                 if (ret == -1) {
  75                         ERR("Unable to launch modprobe -r for module %s",
  76                                         kern_modules_control[i].name);
  77                 } else if (kern_modules_control[i].required
  78                                 && WEXITSTATUS(ret) != 0) {
  79                         ERR("Unable to remove module %s",
  80                                         kern_modules_control[i].name);
  81                 } else {
  82                         DBG("Modprobe removal successful %s",
  83                                         kern_modules_control[i].name);
  84                 }
  85         }
  86
  87 error:
  88         return;
  89 }
  90
  91 /*
  92  * Remove data kernel modules in reverse load order.
  93  */
  94 void modprobe_remove_lttng_data(void)
  95 {
  96         int ret = 0, i;
  97         char modprobe[256];
  98
  99         for (i = ARRAY_SIZE(kern_modules_list) - 1; i >= 0; i--) {
 100                 ret = snprintf(modprobe, sizeof(modprobe),
 101                                 "/sbin/modprobe -r -q %s",
 102                                 kern_modules_list[i].name);
 103                 if (ret < 0) {
 104                         PERROR("snprintf modprobe -r");
 105                         goto error;
 106                 }
 107                 modprobe[sizeof(modprobe) - 1] = '\0';
 108                 ret = system(modprobe);
 109                 if (ret == -1) {
 110                         ERR("Unable to launch modprobe -r for module %s",
 111                                         kern_modules_list[i].name);
 112                 } else if (kern_modules_list[i].required
 113                                 && WEXITSTATUS(ret) != 0) {
 114                         ERR("Unable to remove module %s",
 115                                         kern_modules_list[i].name);
 116                 } else {
 117                         DBG("Modprobe removal successful %s",
 118                                         kern_modules_list[i].name);
 119                 }
 120         }
 121
 122 error:
 123         return;
 124 }
 125
 126 /*
 127  * Remove all kernel modules in reverse order.
 128  */
 129 void modprobe_remove_lttng_all(void)
 130 {
 131         modprobe_remove_lttng_data();
 132         modprobe_remove_lttng_control();
 133 }
 134
 135 /*
 136  * Load control kernel module(s).
 137  */
 138 int modprobe_lttng_control(void)
 139 {
 140         int ret = 0, i;
 141         char modprobe[256];
 142
 143         for (i = 0; i < ARRAY_SIZE(kern_modules_control); i++) {
 144                 ret = snprintf(modprobe, sizeof(modprobe),
 145                                 "/sbin/modprobe %s%s",
 146                                 kern_modules_control[i].required ? "" : "-q ",
 147                                 kern_modules_control[i].name);
 148                 if (ret < 0) {
 149                         PERROR("snprintf modprobe");
 150                         goto error;
 151                 }
 152                 modprobe[sizeof(modprobe) - 1] = '\0';
 153                 ret = system(modprobe);
 154                 if (ret == -1) {
 155                         ERR("Unable to launch modprobe for module %s",
 156                                         kern_modules_control[i].name);
 157                 } else if (kern_modules_control[i].required
 158                                 && WEXITSTATUS(ret) != 0) {
 159                         ERR("Unable to load module %s",
 160                                         kern_modules_control[i].name);
 161                 } else {
 162                         DBG("Modprobe successfully %s",
 163                                         kern_modules_control[i].name);
 164                 }
 165         }
 166
 167 error:
 168         return ret;
 169 }
 170
 171 /*
 172  * Load data kernel module(s).
 173  */
 174 int modprobe_lttng_data(void)
 175 {
 176         int ret = 0, i;
 177         char modprobe[256];
 178
 179         for (i = 0; i < ARRAY_SIZE(kern_modules_list); i++) {
 180                 ret = snprintf(modprobe, sizeof(modprobe),
 181                                 "/sbin/modprobe %s%s",
 182                                 kern_modules_list[i].required ? "" : "-q ",
 183                                 kern_modules_list[i].name);
 184                 if (ret < 0) {
 185                         PERROR("snprintf modprobe");
 186                         goto error;
 187                 }
 188                 modprobe[sizeof(modprobe) - 1] = '\0';
 189                 ret = system(modprobe);
 190                 if (ret == -1) {
 191                         ERR("Unable to launch modprobe for module %s",
 192                                         kern_modules_list[i].name);
 193                 } else if (kern_modules_list[i].required
 194                                 && WEXITSTATUS(ret) != 0) {
 195                         ERR("Unable to load module %s",
 196                                         kern_modules_list[i].name);
 197                 } else {
 198                         DBG("Modprobe successfully %s",
 199                                         kern_modules_list[i].name);
 200                 }
 201         }
 202
 203 error:
 204         return ret;
 205 }
 206
 207 /*
 208  * Load all lttng kernel modules.
 209  */
 210 int modprobe_lttng_all(void)
 211 {
 212         int ret;
 213
 214         ret = modprobe_lttng_control();
 215         if (ret < 0) {
 216                 goto error;
 217         }
 218
 219         ret = modprobe_lttng_data();
 220         if (ret < 0) {
 221                 goto error;
 222         }
 223
 224 error:
 225         return ret;
 226 }