src/test/test_bt_cl.c

   1 /* Copyright (c) 2012-2019, The Tor Project, Inc. */
   2 /* See LICENSE for licensing information */
   3
   4 #include "orconfig.h"
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #ifdef HAVE_SYS_RESOURCE_H
   8 #include <sys/resource.h>
   9 #endif
  10
  11 /* To prevent 'assert' from going away. */
  12 #undef TOR_COVERAGE
  13 #include "core/or/or.h"
  14 #include "lib/err/backtrace.h"
  15 #include "lib/log/log.h"
  16
  17 #ifdef HAVE_UNISTD_H
  18 #include <unistd.h>
  19 #endif
  20
  21 /* -1: no crash.
  22  *  0: crash with a segmentation fault.
  23  *  1x: crash with an assertion failure. */
  24 static int crashtype = 0;
  25
  26 #ifdef __GNUC__
  27 #define NOINLINE __attribute__((noinline))
  28 #endif
  29
  30 int crash(int x) NOINLINE;
  31 int oh_what(int x) NOINLINE;
  32 int a_tangled_web(int x) NOINLINE;
  33 int we_weave(int x) NOINLINE;
  34
  35 #ifdef HAVE_CFLAG_WNULL_DEREFERENCE
  36 DISABLE_GCC_WARNING(null-dereference)
  37 #endif
  38 int
  39 crash(int x)
  40 {
  41   if (crashtype == 0) {
  42 #if defined(__clang_analyzer__) || defined(__COVERITY__)
  43     tor_assert(1 == 0); /* Avert your eyes, clangalyzer and coverity!  You
  44                          * don't need to see us dereference NULL. */
  45 #else
  46     *(volatile int *)0 = 0;
  47 #endif /* defined(__clang_analyzer__) || defined(__COVERITY__) */
  48   } else if (crashtype == 1) {
  49     tor_assert(1 == 0);
  50   } else if (crashtype == -1) {
  51     ;
  52   }
  53
  54   crashtype *= x;
  55   return crashtype;
  56 }
  57 #ifdef HAVE_CFLAG_WNULL_DEREFERENCE
  58 ENABLE_GCC_WARNING(null-dereference)
  59 #endif
  60
  61 int
  62 oh_what(int x)
  63 {
  64   /* We call crash() twice here, so that the compiler won't try to do a
  65    * tail-call optimization.  Only the first call will actually happen, but
  66    * telling the compiler to maybe do the second call will prevent it from
  67    * replacing the first call with a jump. */
  68   return crash(x) + crash(x*2);
  69 }
  70
  71 int
  72 a_tangled_web(int x)
  73 {
  74   return oh_what(x) * 99 + oh_what(x);
  75 }
  76
  77 int
  78 we_weave(int x)
  79 {
  80   return a_tangled_web(x) + a_tangled_web(x+1);
  81 }
  82
  83 int
  84 main(int argc, char **argv)
  85 {
  86   log_severity_list_t severity;
  87
  88   if (argc < 2) {
  89     puts("I take an argument. It should be \"assert\" or \"crash\" or "
  90          "\"backtraces\" or \"none\"");
  91     return 1;
  92   }
  93
  94 #ifdef HAVE_SYS_RESOURCE_H
  95   struct rlimit rlim = { .rlim_cur = 0, .rlim_max = 0 };
  96   setrlimit(RLIMIT_CORE, &rlim);
  97 #endif
  98
  99 #if !(defined(HAVE_EXECINFO_H) && defined(HAVE_BACKTRACE) && \
 100    defined(HAVE_BACKTRACE_SYMBOLS_FD) && defined(HAVE_SIGACTION))
 101     puts("Backtrace reporting is not supported on this platform");
 102     return 77;
 103 #endif
 104
 105   if (!strcmp(argv[1], "assert")) {
 106     crashtype = 1;
 107   } else if (!strcmp(argv[1], "crash")) {
 108     crashtype = 0;
 109   } else if (!strcmp(argv[1], "none")) {
 110     crashtype = -1;
 111   } else if (!strcmp(argv[1], "backtraces")) {
 112     return 0;
 113   } else {
 114     puts("Argument should be \"assert\" or \"crash\" or \"none\"");
 115     return 1;
 116   }
 117
 118   init_logging(1);
 119   set_log_severity_config(LOG_WARN, LOG_ERR, &severity);
 120   add_stream_log(&severity, "stdout", STDOUT_FILENO);
 121   tor_log_update_sigsafe_err_fds();
 122
 123   configure_backtrace_handler(NULL);
 124
 125   printf("%d\n", we_weave(2));
 126
 127   clean_up_backtrace_handler();
 128   logs_free_all();
 129
 130   return 0;
 131 }