tests/regression/ust/multi-lib/multi-lib-test.c

   1 /*
   2  * Copyright (C) - 2018 Francis Deslauriers <francis.deslauriers@efficios.com>
   3  *
   4  * This library is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU Lesser General Public License as published by the
   6  * Free Software Foundation; version 2.1 of the License.
   7  *
   8  * This library 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 Lesser General Public License
  11  * for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this library; if not, write to the Free Software Foundation,
  15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  16  */
  17
  18 #include <dlfcn.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22 #include <popt.h>
  23
  24 #if HAS_CALLSITES
  25 #include "callsites.h"
  26 #endif
  27
  28 void exec_callsite()
  29 {
  30 #if HAS_CALLSITES
  31         call_tracepoint();
  32 #endif
  33 }
  34
  35 void print_list(void)
  36 {
  37         fprintf(stderr, "Test list (-t X):\n");
  38         fprintf(stderr, "\t0: dlopen() all libraries pass in arguments and execute "
  39                         "the callsite.\n");
  40         fprintf(stderr, "\t1: simulate the upgrade of a probe provider using dlopen() and dlclose(). \n");
  41         fprintf(stderr, "\t2: simulate the upgrade of a library containing the callsites using dlopen() and dlclose(). \n");
  42 }
  43
  44 int dl_open_all(int nb_libraries, char **libraries)
  45 {
  46         int i, ret = 0;
  47         void **handles;
  48
  49         handles = malloc(nb_libraries * sizeof(void *));
  50         if (!handles) {
  51                 ret = -1;
  52                 goto error;
  53         }
  54
  55         /* Iterate over the libs to dlopen and save the handles. */
  56         for (i = 0; i < nb_libraries; i++) {
  57                 handles[i] = dlopen(libraries[i], RTLD_NOW);
  58                 if (!handles[i]) {
  59                         ret = -1;
  60                         goto error;
  61                 }
  62         }
  63
  64         exec_callsite();
  65 error:
  66         free(handles);
  67         return ret;
  68 }
  69
  70 /*
  71  * Takes 2 paths to libraries, dlopen() the first, trace, dlopen() the second,
  72  * and dlclose the first to simulate the upgrade of a library.
  73  */
  74 int upgrade_lib(int nb_libraries, char **libraries)
  75 {
  76         int i, ret = 0;
  77         void *handles[2];
  78
  79         if (nb_libraries != 2) {
  80                 ret = -1;
  81                 goto error;
  82         }
  83
  84         /* Iterate over the libs to dlopen and save the handles. */
  85         for (i = 0; i < nb_libraries; i++) {
  86                 handles[i] = dlopen(libraries[i], RTLD_NOW);
  87                 if (!handles[i]) {
  88                         ret = -1;
  89                         goto error;
  90                 }
  91
  92                 exec_callsite();
  93         }
  94
  95         ret = dlclose(handles[0]);
  96         if (ret) {
  97                 goto error;
  98         }
  99
 100         exec_callsite();
 101
 102 error:
 103         return ret;
 104 }
 105
 106 /*
 107  * Simulate the upgrade of a library containing a callsite.
 108  * Receives two libraries containing callsites for the same tracepoint.
 109  */
 110 int upgrade_callsite(int nb_libraries, char **libraries)
 111 {
 112         int ret = 0;
 113         void *handles[2];
 114         void (*fct_ptr[2])(void);
 115
 116         if (nb_libraries != 2) {
 117                 ret = -1;
 118                 goto error;
 119         }
 120
 121         /* Load the probes in the first library. */
 122         handles[0] = dlopen(libraries[0], RTLD_NOW);
 123         if (!handles[0]) {
 124                 ret = -1;
 125                 goto error;
 126         }
 127
 128         /*
 129          * Get the pointer to the old function containing the callsite and call it.
 130          */
 131         fct_ptr[0] = dlsym(handles[0], "call_tracepoint");
 132         if (!fct_ptr[0]) {
 133                 ret = -1;
 134                 goto error;
 135         }
 136         fct_ptr[0]();
 137
 138         /* Load the new callsite library. */
 139         handles[1] = dlopen(libraries[1], RTLD_NOW);
 140         if (!handles[1]) {
 141                 ret = -1;
 142                 goto error;
 143         }
 144
 145         /*
 146          * Get the pointer to the new function containing the callsite and call it.
 147          */
 148         fct_ptr[1] = dlsym(handles[1], "call_tracepoint");
 149         if (!fct_ptr[1]) {
 150                 ret = -1;
 151                 goto error;
 152         }
 153         fct_ptr[1]();
 154
 155         /* Unload the old callsite library. */
 156         ret = dlclose(handles[0]);
 157         if (ret) {
 158                 goto error;
 159         }
 160
 161         /* Call the function containing the callsite in the new library. */
 162         fct_ptr[1]();
 163
 164         ret = dlclose(handles[1]);
 165         if (ret) {
 166                 goto error;
 167         }
 168
 169 error:
 170         return ret;
 171 }
 172
 173 int main(int argc, const char **argv)
 174 {
 175         int c, ret = 0, test = -1, nb_libraries = 0;
 176         char **libraries = NULL;
 177         poptContext optCon;
 178         struct poptOption optionsTable[] = {
 179                         { "test", 't', POPT_ARG_INT, &test, 0, "Test to run", NULL },
 180                         { "list", 'l', 0, 0, 'l', "List of tests (-t X)", NULL },
 181                         POPT_AUTOHELP
 182                         { NULL, 0, 0, NULL, 0 }
 183         };
 184
 185         optCon = poptGetContext(NULL, argc, argv, optionsTable, 0);
 186         if (argc < 2) {
 187                 poptPrintUsage(optCon, stderr, 0);
 188                 ret = -1;
 189                 goto error;
 190         }
 191
 192         while ((c = poptGetNextOpt(optCon)) >= 0) {
 193                 switch(c) {
 194                 case 'l':
 195                         print_list();
 196                         goto error;
 197                 }
 198         }
 199
 200         /*
 201          * Populate the libraries array with the arguments passed to the process.
 202          */
 203         while (poptPeekArg(optCon) != NULL) {
 204                 char **realloced_libraries = NULL;
 205
 206                 nb_libraries++;
 207                 realloced_libraries = realloc(libraries, nb_libraries * sizeof(char *));
 208                 if (!realloced_libraries) {
 209                         ret = -1;
 210                         goto error;
 211                 }
 212                 libraries = realloced_libraries;
 213                 libraries[nb_libraries - 1] = (char *) poptGetArg(optCon);
 214         }
 215
 216         switch(test) {
 217         case 0:
 218 #if HAS_CALLSITES
 219                 ret = dl_open_all(nb_libraries, libraries);
 220 #else
 221                 fprintf(stderr, "Test not implemented for configuration "
 222                                 "(HAS_CALLSITES=%d)\n", HAS_CALLSITES == 1);
 223 #endif
 224                 break;
 225         case 1:
 226 #if HAS_CALLSITES
 227                 ret = upgrade_lib(nb_libraries, libraries);
 228 #else
 229                 fprintf(stderr, "Test not implemented for configuration "
 230                                 "(HAS_CALLSITES=%d)\n", HAS_CALLSITES == 1);
 231 #endif
 232                 break;
 233         case 2:
 234 #if !HAS_CALLSITES
 235                 ret = upgrade_callsite(nb_libraries, libraries);
 236 #else
 237                 fprintf(stderr, "Test not implemented for configuration "
 238                                 "(HAS_CALLSITES=%d)\n", HAS_CALLSITES == 1);
 239 #endif
 240                 break;
 241         default:
 242                 fprintf(stderr, "Test %d not implemented\n", test);
 243                 ret = -1;
 244                 break;
 245         }
 246 error:
 247         free(libraries);
 248         poptFreeContext(optCon);
 249         return ret;
 250 }