for jackdbus, setup SIGSEGV magic that prints nice stack in logfile

git-svn-id: http://subversion.jackaudio.org/jack/jack2/trunk/jackmp@2378 0c269be4-1314-0410-8aa9-9f06e86f4224

linux/dbus/SConscript

@@ -71,6 +71,7 @@ jackenv.Install(env['BINDIR'], jackenv.Program('jackdbus', [
 #    'xml_libxml.c',
 #    'xml_nop.c',
     'xml_write_raw.c',
+    'sigsegv.c',
     ]))
 jackenv.Alias('install', env['BINDIR'])
 

linux/dbus/jackdbus.c

@@ -37,6 +37,7 @@
 #include "jack/jack.h"
 #include "jack/jslist.h"
 #include "jack/control.h"
+#include "sigsegv.h"
 
 FILE *g_logfile;
 char *g_jackdbus_config_dir;
@@ -744,6 +745,9 @@ main (int argc, char **argv)
     jack_set_error_function(jack_dbus_error_callback);
     jack_set_info_function(jack_dbus_info_callback);
 
+    /* setup our SIGSEGV magic that prints nice stack in our logfile */
+    setup_sigsegv();
+
     jack_info("------------------");
     jack_info("Controller activated. Version %s (%s)", jack_get_version_string(), JACK_SVNREVISION);
 

linux/dbus/sigsegv.c

@@ -0,0 +1,140 @@
+/**
+ * This source file is used to print out a stack-trace when your program
+ * segfaults.  It is relatively reliable and spot-on accurate.
+ *
+ * This code is in the public domain.  Use it as you see fit, some credit
+ * would be appreciated, but is not a prerequisite for usage.  Feedback
+ * on it's use would encourage further development and maintenance.
+ *
+ * Author:  Jaco Kroon <jaco@kroon.co.za>
+ *
+ * Copyright (C) 2005 - 2008 Jaco Kroon
+ */
+
+//#define NO_CPP_DEMANGLE
+#define SIGSEGV_NO_AUTO_INIT
+
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE
+#endif
+
+#include <memory.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <signal.h>
+#include <ucontext.h>
+#include <dlfcn.h>
+#include <execinfo.h>
+#include <errno.h>
+#ifndef NO_CPP_DEMANGLE
+//#include <cxxabi.h>
+char * __cxa_demangle(const char * __mangled_name, char * __output_buffer, size_t * __length, int * __status);
+#endif
+
+#if defined(REG_RIP)
+# define SIGSEGV_STACK_IA64
+# define REGFORMAT "%016lx"
+#elif defined(REG_EIP)
+# define SIGSEGV_STACK_X86
+# define REGFORMAT "%08x"
+#else
+# define SIGSEGV_STACK_GENERIC
+# define REGFORMAT "%x"
+#endif
+
+static void signal_segv(int signum, siginfo_t* info, void*ptr) {
+    static const char *si_codes[3] = {"", "SEGV_MAPERR", "SEGV_ACCERR"};
+
+    size_t i;
+    ucontext_t *ucontext = (ucontext_t*)ptr;
+
+#if defined(SIGSEGV_STACK_X86) || defined(SIGSEGV_STACK_IA64)
+    int f = 0;
+    Dl_info dlinfo;
+    void **bp = 0;
+    void *ip = 0;
+#else
+    void *bt[20];
+    char **strings;
+    size_t sz;
+#endif
+
+    jack_error("Segmentation Fault!");
+    jack_error("info.si_signo = %d", signum);
+    jack_error("info.si_errno = %d", info->si_errno);
+    jack_error("info.si_code  = %d (%s)", info->si_code, si_codes[info->si_code]);
+    jack_error("info.si_addr  = %p", info->si_addr);
+    for(i = 0; i < NGREG; i++)
+        jack_error("reg[%02d]       = 0x" REGFORMAT, i, ucontext->uc_mcontext.gregs[i]);
+
+#if defined(SIGSEGV_STACK_X86) || defined(SIGSEGV_STACK_IA64)
+# if defined(SIGSEGV_STACK_IA64)
+    ip = (void*)ucontext->uc_mcontext.gregs[REG_RIP];
+    bp = (void**)ucontext->uc_mcontext.gregs[REG_RBP];
+# elif defined(SIGSEGV_STACK_X86)
+    ip = (void*)ucontext->uc_mcontext.gregs[REG_EIP];
+    bp = (void**)ucontext->uc_mcontext.gregs[REG_EBP];
+# endif
+
+    jack_error("Stack trace:");
+    while(bp && ip) {
+        if(!dladdr(ip, &dlinfo))
+            break;
+
+        const char *symname = dlinfo.dli_sname;
+#ifndef NO_CPP_DEMANGLE
+        int status;
+        char *tmp = __cxa_demangle(symname, NULL, 0, &status);
+
+        if(status == 0 && tmp)
+            symname = tmp;
+#endif
+
+        jack_error("% 2d: %p <%s+%u> (%s)",
+                ++f,
+                ip,
+                symname,
+                (unsigned)(ip - dlinfo.dli_saddr),
+                dlinfo.dli_fname);
+
+#ifndef NO_CPP_DEMANGLE
+        if(tmp)
+            free(tmp);
+#endif
+
+        if(dlinfo.dli_sname && !strcmp(dlinfo.dli_sname, "main"))
+            break;
+
+        ip = bp[1];
+        bp = (void**)bp[0];
+    }
+#else
+    jack_error("Stack trace (non-dedicated):");
+    sz = backtrace(bt, 20);
+    strings = backtrace_symbols(bt, sz);
+
+    for(i = 0; i < sz; ++i)
+        jack_error("%s", strings[i]);
+#endif
+    jack_error("End of stack trace");
+    exit (-1);
+}
+
+int setup_sigsegv() {
+    struct sigaction action;
+    memset(&action, 0, sizeof(action));
+    action.sa_sigaction = signal_segv;
+    action.sa_flags = SA_SIGINFO;
+    if(sigaction(SIGSEGV, &action, NULL) < 0) {
+        jack_error("sigaction failed. errno is %d (%s)", errno, strerror(errno));
+        return 0;
+    }
+
+    return 1;
+}
+
+#ifndef SIGSEGV_NO_AUTO_INIT
+static void __attribute((constructor)) init(void) {
+    setup_sigsegv();
+}
+#endif

linux/dbus/sigsegv.h

@@ -0,0 +1,9 @@
+#ifndef __SIGSEGV_H__
+#define __SIGSEGV_H__
+
+#ifdef __cplusplus
+extern "C"
+#endif
+int setup_sigsegv();
+
+#endif