dbus/sigsegv.c

   1 /**
   2  * This source file is used to print out a stack-trace when your program
   3  * segfaults.  It is relatively reliable and spot-on accurate.
   4  *
   5  * This code is in the public domain.  Use it as you see fit, some credit
   6  * would be appreciated, but is not a prerequisite for usage.  Feedback
   7  * on it's use would encourage further development and maintenance.
   8  *
   9  * Author:  Jaco Kroon <jaco@kroon.co.za>
  10  *
  11  * Copyright (C) 2005 - 2008 Jaco Kroon
  12  */
  13
  14 #if defined(HAVE_CONFIG_H)
  15 #include "config.h"
  16 #endif
  17
  18 //#define NO_CPP_DEMANGLE
  19 #define SIGSEGV_NO_AUTO_INIT
  20
  21 #ifndef _GNU_SOURCE
  22 # define _GNU_SOURCE
  23 #endif
  24
  25 #include <memory.h>
  26 #include <stdlib.h>
  27 #include <stdio.h>
  28 #include <signal.h>
  29 #include <dlfcn.h>
  30 #include <execinfo.h>
  31 #include <errno.h>
  32 #ifndef NO_CPP_DEMANGLE
  33 char * __cxa_demangle(const char * __mangled_name, char * __output_buffer, size_t * __length, int * __status);
  34 #endif
  35
  36 #include "JackError.h"
  37
  38 #if defined(REG_RIP)
  39 # define SIGSEGV_STACK_IA64
  40 # define REGFORMAT "%016lx"
  41 #elif defined(REG_EIP)
  42 # define SIGSEGV_STACK_X86
  43 # define REGFORMAT "%08x"
  44 #else
  45 # define SIGSEGV_STACK_GENERIC
  46 # define REGFORMAT "%x"
  47 #endif
  48
  49 #ifdef __APPLE__
  50
  51 // TODO : does not compile yet on OSX
  52 static void signal_segv(int signum, siginfo_t* info, void*ptr)
  53 {}
  54
  55 #else
  56
  57 #include <ucontext.h>
  58
  59 static void signal_segv(int signum, siginfo_t* info, void*ptr) {
  60     static const char *si_codes[3] = {"", "SEGV_MAPERR", "SEGV_ACCERR"};
  61
  62     size_t i;
  63     ucontext_t *ucontext = (ucontext_t*)ptr;
  64
  65 #if defined(SIGSEGV_STACK_X86) || defined(SIGSEGV_STACK_IA64)
  66     int f = 0;
  67     Dl_info dlinfo;
  68     void **bp = 0;
  69     void *ip = 0;
  70 #else
  71     void *bt[20];
  72     char **strings;
  73     size_t sz;
  74 #endif
  75
  76     if (signum == SIGSEGV)
  77     {
  78         jack_error("Segmentation Fault!");
  79     }
  80     else if (signum == SIGABRT)
  81     {
  82         jack_error("Abort!");
  83     }
  84     else if (signum == SIGILL)
  85     {
  86         jack_error("Illegal instruction!");
  87     }
  88     else if (signum == SIGFPE)
  89     {
  90         jack_error("Floating point exception!");
  91     }
  92     else
  93     {
  94         jack_error("Unknown bad signal catched!");
  95     }
  96
  97     jack_error("info.si_signo = %d", signum);
  98     jack_error("info.si_errno = %d", info->si_errno);
  99     jack_error("info.si_code  = %d (%s)", info->si_code, si_codes[info->si_code]);
 100     jack_error("info.si_addr  = %p", info->si_addr);
 101     for(i = 0; i < NGREG; i++)
 102         jack_error("reg[%02d]       = 0x" REGFORMAT, i, ucontext->uc_mcontext.gregs[i]);
 103
 104 #if defined(SIGSEGV_STACK_X86) || defined(SIGSEGV_STACK_IA64)
 105 # if defined(SIGSEGV_STACK_IA64)
 106     ip = (void*)ucontext->uc_mcontext.gregs[REG_RIP];
 107     bp = (void**)ucontext->uc_mcontext.gregs[REG_RBP];
 108 # elif defined(SIGSEGV_STACK_X86)
 109     ip = (void*)ucontext->uc_mcontext.gregs[REG_EIP];
 110     bp = (void**)ucontext->uc_mcontext.gregs[REG_EBP];
 111 # endif
 112
 113     jack_error("Stack trace:");
 114     while(bp && ip) {
 115         if(!dladdr(ip, &dlinfo))
 116             break;
 117
 118         const char *symname = dlinfo.dli_sname;
 119 #ifndef NO_CPP_DEMANGLE
 120         int status;
 121         char *tmp = __cxa_demangle(symname, NULL, 0, &status);
 122
 123         if(status == 0 && tmp)
 124             symname = tmp;
 125 #endif
 126
 127         jack_error("% 2d: %p <%s+%u> (%s)",
 128                 ++f,
 129                 ip,
 130                 symname,
 131                 (unsigned)(ip - dlinfo.dli_saddr),
 132                 dlinfo.dli_fname);
 133
 134 #ifndef NO_CPP_DEMANGLE
 135         if(tmp)
 136             free(tmp);
 137 #endif
 138
 139         if(dlinfo.dli_sname && !strcmp(dlinfo.dli_sname, "main"))
 140             break;
 141
 142         ip = bp[1];
 143         bp = (void**)bp[0];
 144     }
 145 #else
 146     jack_error("Stack trace (non-dedicated):");
 147     sz = backtrace(bt, 20);
 148     strings = backtrace_symbols(bt, sz);
 149
 150     for(i = 0; i < sz; ++i)
 151         jack_error("%s", strings[i]);
 152 #endif
 153     jack_error("End of stack trace");
 154     exit (-1);
 155 }
 156
 157 #endif
 158
 159 int setup_sigsegv() {
 160     struct sigaction action;
 161
 162     memset(&action, 0, sizeof(action));
 163     action.sa_sigaction = signal_segv;
 164     action.sa_flags = SA_SIGINFO;
 165     if(sigaction(SIGSEGV, &action, NULL) < 0) {
 166         jack_error("sigaction failed. errno is %d (%s)", errno, strerror(errno));
 167         return 0;
 168     }
 169
 170     if(sigaction(SIGILL, &action, NULL) < 0) {
 171         jack_error("sigaction failed. errno is %d (%s)", errno, strerror(errno));
 172         return 0;
 173     }
 174
 175     if(sigaction(SIGABRT, &action, NULL) < 0) {
 176         jack_error("sigaction failed. errno is %d (%s)", errno, strerror(errno));
 177         return 0;
 178     }
 179
 180     if(sigaction(SIGFPE, &action, NULL) < 0) {
 181         jack_error("sigaction failed. errno is %d (%s)", errno, strerror(errno));
 182         return 0;
 183     }
 184
 185     return 1;
 186 }
 187
 188 #ifndef SIGSEGV_NO_AUTO_INIT
 189 static void __attribute((constructor)) init(void) {
 190     setup_sigsegv();
 191 }
 192 #endif