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 #ifdef HAVE_EXECINFO_H
  31 # include <execinfo.h>
  32 #endif
  33 #include <errno.h>
  34 #ifndef NO_CPP_DEMANGLE
  35 char * __cxa_demangle(const char * __mangled_name, char * __output_buffer, size_t * __length, int * __status);
  36 #endif
  37
  38 #include "jack/control.h"
  39
  40 #if defined(REG_RIP)
  41 # define SIGSEGV_STACK_IA64
  42 # define REGFORMAT "%016lx"
  43 #elif defined(REG_EIP)
  44 # define SIGSEGV_STACK_X86
  45 # define REGFORMAT "%08x"
  46 #else
  47 # define SIGSEGV_STACK_GENERIC
  48 # define REGFORMAT "%x"
  49 #endif
  50
  51 #ifdef __APPLE__
  52
  53 // TODO : does not compile yet on OSX
  54 static void signal_segv(int signum, siginfo_t* info, void*ptr)
  55 {}
  56
  57 #else
  58
  59 #include <ucontext.h>
  60
  61 static void signal_segv(int signum, siginfo_t* info, void*ptr) {
  62     static const char *si_codes[3] = {"", "SEGV_MAPERR", "SEGV_ACCERR"};
  63
  64     const char *si_code_str;
  65     ucontext_t *ucontext = (ucontext_t*)ptr;
  66
  67 #if (defined(HAVE_UCONTEXT) && defined(HAVE_NGREG)) || defined(HAVE_EXECINFO_H)
  68     size_t i;
  69 #endif
  70 #if defined(SIGSEGV_STACK_X86) || defined(SIGSEGV_STACK_IA64)
  71     int f = 0;
  72     Dl_info dlinfo;
  73     void **bp = 0;
  74     void *ip = 0;
  75 #else
  76     void *bt[20];
  77     char **strings;
  78     size_t sz;
  79 #endif
  80
  81     if (signum == SIGSEGV)
  82     {
  83         jack_error("Segmentation Fault!");
  84     }
  85     else if (signum == SIGABRT)
  86     {
  87         jack_error("Abort!");
  88     }
  89     else if (signum == SIGILL)
  90     {
  91         jack_error("Illegal instruction!");
  92     }
  93     else if (signum == SIGFPE)
  94     {
  95         jack_error("Floating point exception!");
  96     }
  97     else
  98     {
  99         jack_error("Unknown bad signal caught!");
 100     }
 101
 102     if (info->si_code >= 0 && info->si_code < 3)
 103         si_code_str = si_codes[info->si_code];
 104     else
 105         si_code_str = "unknown";
 106
 107     jack_error("info.si_signo = %d", signum);
 108     jack_error("info.si_errno = %d", info->si_errno);
 109     jack_error("info.si_code  = %d (%s)", info->si_code, si_code_str);
 110     jack_error("info.si_addr  = %p", info->si_addr);
 111 #if defined(HAVE_UCONTEXT) && defined(HAVE_NGREG)
 112     for(i = 0; i < NGREG; i++)
 113         jack_error("reg[%02d]       = 0x" REGFORMAT, i,
 114 #if defined(HAVE_UCONTEXT_GP_REGS)
 115                 ucontext->uc_mcontext.gp_regs[i]
 116 #elif defined(HAVE_UCONTEXT_UC_REGS)
 117                 ucontext->uc_mcontext.uc_regs[i]
 118 #elif defined(HAVE_UCONTEXT_MC_GREGS)
 119                 ucontext->uc_mcontext.mc_gregs[i]
 120 #elif defined(HAVE_UCONTEXT_GREGS)
 121                 ucontext->uc_mcontext.gregs[i]
 122 #endif
 123                 );
 124 #endif /* defined(HAVE_UCONTEXT) && defined(HAVE_NGREG) */
 125
 126 #if defined(SIGSEGV_STACK_X86) || defined(SIGSEGV_STACK_IA64)
 127 # if defined(SIGSEGV_STACK_IA64)
 128     ip = (void*)ucontext->uc_mcontext.gregs[REG_RIP];
 129     bp = (void**)ucontext->uc_mcontext.gregs[REG_RBP];
 130 # elif defined(SIGSEGV_STACK_X86)
 131     ip = (void*)ucontext->uc_mcontext.gregs[REG_EIP];
 132     bp = (void**)ucontext->uc_mcontext.gregs[REG_EBP];
 133 # endif
 134
 135     jack_error("Stack trace:");
 136     while(bp && ip) {
 137         if(!dladdr(ip, &dlinfo))
 138             break;
 139
 140         const char *symname = dlinfo.dli_sname;
 141 #ifndef NO_CPP_DEMANGLE
 142         int status;
 143         char *tmp = __cxa_demangle(symname, NULL, 0, &status);
 144
 145         if(status == 0 && tmp)
 146             symname = tmp;
 147 #endif
 148
 149         jack_error("% 2d: %p <%s+%u> (%s)",
 150                 ++f,
 151                 ip,
 152                 symname,
 153                 (unsigned)(ip - dlinfo.dli_saddr),
 154                 dlinfo.dli_fname);
 155
 156 #ifndef NO_CPP_DEMANGLE
 157         if(tmp)
 158             free(tmp);
 159 #endif
 160
 161         if(dlinfo.dli_sname && !strcmp(dlinfo.dli_sname, "main"))
 162             break;
 163
 164         ip = bp[1];
 165         bp = (void**)bp[0];
 166     }
 167 #else
 168 # ifdef HAVE_EXECINFO_H
 169     jack_error("Stack trace (non-dedicated):");
 170     sz = backtrace(bt, 20);
 171     strings = backtrace_symbols(bt, sz);
 172
 173     for(i = 0; i < sz; ++i)
 174         jack_error("%s", strings[i]);
 175 # else
 176     jack_error("Stack trace not available");
 177 # endif
 178 #endif
 179     jack_error("End of stack trace");
 180     exit (-1);
 181 }
 182
 183 #endif
 184
 185 int setup_sigsegv() {
 186     struct sigaction action;
 187
 188     memset(&action, 0, sizeof(action));
 189     action.sa_sigaction = signal_segv;
 190 #ifdef SA_SIGINFO
 191     action.sa_flags = SA_SIGINFO;
 192 #endif
 193     if(sigaction(SIGSEGV, &action, NULL) < 0) {
 194         jack_error("sigaction failed. errno is %d (%s)", errno, strerror(errno));
 195         return 0;
 196     }
 197
 198     if(sigaction(SIGILL, &action, NULL) < 0) {
 199         jack_error("sigaction failed. errno is %d (%s)", errno, strerror(errno));
 200         return 0;
 201     }
 202
 203     if(sigaction(SIGABRT, &action, NULL) < 0) {
 204         jack_error("sigaction failed. errno is %d (%s)", errno, strerror(errno));
 205         return 0;
 206     }
 207
 208     if(sigaction(SIGFPE, &action, NULL) < 0) {
 209         jack_error("sigaction failed. errno is %d (%s)", errno, strerror(errno));
 210         return 0;
 211     }
 212
 213     return 1;
 214 }
 215
 216 #ifndef SIGSEGV_NO_AUTO_INIT
 217 static void __attribute((constructor)) init(void) {
 218     setup_sigsegv();
 219 }
 220 #endif