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 "jack/control.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     const char *si_code_str;
  64     ucontext_t *ucontext = (ucontext_t*)ptr;
  65
  66 #if defined(SIGSEGV_STACK_X86) || defined(SIGSEGV_STACK_IA64)
  67     int f = 0;
  68     Dl_info dlinfo;
  69     void **bp = 0;
  70     void *ip = 0;
  71 #else
  72     void *bt[20];
  73     char **strings;
  74     size_t sz;
  75 #endif
  76
  77     if (signum == SIGSEGV)
  78     {
  79         jack_error("Segmentation Fault!");
  80     }
  81     else if (signum == SIGABRT)
  82     {
  83         jack_error("Abort!");
  84     }
  85     else if (signum == SIGILL)
  86     {
  87         jack_error("Illegal instruction!");
  88     }
  89     else if (signum == SIGFPE)
  90     {
  91         jack_error("Floating point exception!");
  92     }
  93     else
  94     {
  95         jack_error("Unknown bad signal catched!");
  96     }
  97
  98     if (info->si_code >= 0 && info->si_code < 3)
  99         si_code_str = si_codes[info->si_code];
 100     else
 101         si_code_str = "unknown";
 102
 103     jack_error("info.si_signo = %d", signum);
 104     jack_error("info.si_errno = %d", info->si_errno);
 105     jack_error("info.si_code  = %d (%s)", info->si_code, si_code_str);
 106     jack_error("info.si_addr  = %p", info->si_addr);
 107 #if !defined(__alpha__) && !defined(__ia64__) && !defined(__FreeBSD_kernel__) && !defined(__arm__) && !defined(__hppa__) && !defined(__sh__)
 108     for(i = 0; i < NGREG; i++)
 109         jack_error("reg[%02d]       = 0x" REGFORMAT, i,
 110 #if defined(__powerpc__)
 111                 ucontext->uc_mcontext.uc_regs[i]
 112 #elif defined(__sparc__) && defined(__arch64__)
 113                 ucontext->uc_mcontext.mc_gregs[i]
 114 #else
 115                 ucontext->uc_mcontext.gregs[i]
 116 #endif
 117                 );
 118 #endif /* alpha, ia64, kFreeBSD, arm, hppa */
 119
 120 #if defined(SIGSEGV_STACK_X86) || defined(SIGSEGV_STACK_IA64)
 121 # if defined(SIGSEGV_STACK_IA64)
 122     ip = (void*)ucontext->uc_mcontext.gregs[REG_RIP];
 123     bp = (void**)ucontext->uc_mcontext.gregs[REG_RBP];
 124 # elif defined(SIGSEGV_STACK_X86)
 125     ip = (void*)ucontext->uc_mcontext.gregs[REG_EIP];
 126     bp = (void**)ucontext->uc_mcontext.gregs[REG_EBP];
 127 # endif
 128
 129     jack_error("Stack trace:");
 130     while(bp && ip) {
 131         if(!dladdr(ip, &dlinfo))
 132             break;
 133
 134         const char *symname = dlinfo.dli_sname;
 135 #ifndef NO_CPP_DEMANGLE
 136         int status;
 137         char *tmp = __cxa_demangle(symname, NULL, 0, &status);
 138
 139         if(status == 0 && tmp)
 140             symname = tmp;
 141 #endif
 142
 143         jack_error("% 2d: %p <%s+%u> (%s)",
 144                 ++f,
 145                 ip,
 146                 symname,
 147                 (unsigned)(ip - dlinfo.dli_saddr),
 148                 dlinfo.dli_fname);
 149
 150 #ifndef NO_CPP_DEMANGLE
 151         if(tmp)
 152             free(tmp);
 153 #endif
 154
 155         if(dlinfo.dli_sname && !strcmp(dlinfo.dli_sname, "main"))
 156             break;
 157
 158         ip = bp[1];
 159         bp = (void**)bp[0];
 160     }
 161 #else
 162     jack_error("Stack trace (non-dedicated):");
 163     sz = backtrace(bt, 20);
 164     strings = backtrace_symbols(bt, sz);
 165
 166     for(i = 0; i < sz; ++i)
 167         jack_error("%s", strings[i]);
 168 #endif
 169     jack_error("End of stack trace");
 170     exit (-1);
 171 }
 172
 173 #endif
 174
 175 int setup_sigsegv() {
 176     struct sigaction action;
 177
 178     memset(&action, 0, sizeof(action));
 179     action.sa_sigaction = signal_segv;
 180     action.sa_flags = SA_SIGINFO;
 181     if(sigaction(SIGSEGV, &action, NULL) < 0) {
 182         jack_error("sigaction failed. errno is %d (%s)", errno, strerror(errno));
 183         return 0;
 184     }
 185
 186     if(sigaction(SIGILL, &action, NULL) < 0) {
 187         jack_error("sigaction failed. errno is %d (%s)", errno, strerror(errno));
 188         return 0;
 189     }
 190
 191     if(sigaction(SIGABRT, &action, NULL) < 0) {
 192         jack_error("sigaction failed. errno is %d (%s)", errno, strerror(errno));
 193         return 0;
 194     }
 195
 196     if(sigaction(SIGFPE, &action, NULL) < 0) {
 197         jack_error("sigaction failed. errno is %d (%s)", errno, strerror(errno));
 198         return 0;
 199     }
 200
 201     return 1;
 202 }
 203
 204 #ifndef SIGSEGV_NO_AUTO_INIT
 205 static void __attribute((constructor)) init(void) {
 206     setup_sigsegv();
 207 }
 208 #endif