--- a/configure.in	Sun Nov 19 01:35:37 2006 +0200
+++ b/configure.in	Sun Nov 19 15:30:38 2006 +0200
@@ -19,7 +19,7 @@
   sys/uio.h sys/sysmacros.h sys/resource.h sys/select.h libgen.h \
   sys/quota.h sys/fs/ufs_quota.h ufs/ufs/quota.h jfs/quota.h \
   mntent.h sys/mnttab.h sys/event.h sys/time.h sys/mkdev.h linux/dqblk_xfs.h \
-  xfs/xqm.h sasl.h sasl/sasl.h)
+  xfs/xqm.h sasl.h sasl/sasl.h execinfo.h ucontext.h)
 
 AC_ARG_ENABLE(ipv6,
 [  --enable-ipv6           Enable IPv6 support (default)],
@@ -411,7 +411,7 @@
                strcasecmp stricmp vsnprintf vsyslog writev pread \
 	       setrlimit setproctitle seteuid setreuid setegid setresgid \
 	       strtoull strtouq setpriority quotactl getmntent kqueue kevent \
-           getrusage)
+	       getrusage backtrace_symbols walkcontext)
 
 dnl * I/O loop function
 have_ioloop=no

--- a/src/lib/Makefile.am	Sun Nov 19 01:35:37 2006 +0200
+++ b/src/lib/Makefile.am	Sun Nov 19 15:30:38 2006 +0200
@@ -1,6 +1,7 @@
 noinst_LIBRARIES = liblib.a
 
 liblib_a_SOURCES = \
+	backtrace-string.c \
 	base64.c \
 	bsearch-insert-pos.c \
 	buffer.c \
@@ -89,6 +90,7 @@
 noinst_HEADERS = \
 	array.h \
 	array-decl.h \
+	backtrace-string.h \
 	base64.h \
 	bsearch-insert-pos.h \
 	buffer.h \

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib/backtrace-string.c	Sun Nov 19 15:30:38 2006 +0200
@@ -0,0 +1,87 @@
+/* Copyright (c) 2006 Timo Sirainen */
+
+#include "lib.h"
+#include "str.h"
+#include "backtrace-string.h"
+
+#define MAX_STACK_SIZE 30
+#define STACK_SKIP_COUNT 2
+
+#if defined(HAVE_BACKTRACE_SYMBOLS) && defined(HAVE_EXECINFO_H)
+/* Linux */
+#include <execinfo.h>
+#include <stdlib.h>
+
+int backtrace_append(string_t *str)
+{
+	void *stack[MAX_STACK_SIZE];
+	char **strings;
+	int ret, i;
+
+	ret = backtrace(stack, sizeof(stack)/sizeof(stack[0]));
+	if (ret <= STACK_SKIP_COUNT)
+		return -1;
+
+	strings = backtrace_symbols(stack, ret);
+	for (i = STACK_SKIP_COUNT; i < ret; i++) {
+		if (i > STACK_SKIP_COUNT)
+			str_append(str, " -> ");
+		str_append(str, strings[i]);
+	}
+	free(strings);
+	return 0;
+}
+#elif defined(HAVE_WALKCONTEXT) && defined(HAVE_UCONTEXT_H)
+/* Solaris */
+#include <ucontext.h>
+
+struct walk_context {
+	string_t *str;
+	unsigned int pos;
+};
+
+static int walk_callback(uintptr_t ptr, int signo __attr_unused__,
+			 void *context)
+{
+	struct walk_context *ctx = context;
+
+	if (ctx->pos >= STACK_SKIP_COUNT) {
+		if (ctx->pos > STACK_SKIP_COUNT)
+			str_append(ctx->str, " -> ");
+		str_printfa(ctx->str, "0x%p", (void *)ptr);
+	}
+	ctx->pos++;
+	return 0;
+}
+
+int backtrace_append(string_t *str)
+{
+	ucontext_t uc;
+	struct walk_context ctx;
+
+	if (getcontext(&uc) < 0)
+		return -1;
+
+	ctx.str = str;
+	ctx.pos = 0;
+	walkcontext(&uc, walk_callback, &ctx);
+	return 0;
+}
+#else
+int backtrace_append(string_t *str __attr_unused__)
+{
+	return -1;
+}
+#endif
+
+int backtrace_get(const char **backtrace_r)
+{
+	string_t *str;
+
+	str = t_str_new(512);
+	if (backtrace_append(str) < 0)
+		return -1;
+
+	*backtrace_r = str_c(str);
+	return 0;
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib/backtrace-string.h	Sun Nov 19 15:30:38 2006 +0200
@@ -0,0 +1,8 @@
+#ifndef __BACKTRACE_STRING_H
+#define __BACKTRACE_STRING_H
+
+/* Returns 0 if ok, -1 if failure. */
+int backtrace_append(string_t *str);
+int backtrace_get(const char **backtrace_r);
+
+#endif

--- a/src/lib/failures.c	Sun Nov 19 01:35:37 2006 +0200
+++ b/src/lib/failures.c	Sun Nov 19 15:30:38 2006 +0200
@@ -2,6 +2,7 @@
 
 #include "lib.h"
 #include "str.h"
+#include "backtrace-string.h"
 #include "write-full.h"
 #include "fd-close-on-exec.h"
 #include "printf-upper-bound.h"
@@ -120,7 +121,11 @@
 static void __attr_format__(1, 0)
 default_panic_handler(const char *format, va_list args)
 {
+	const char *backtrace;
+
 	(void)default_handler("Panic: ", log_fd, format, args);
+	if (backtrace_get(&backtrace) == 0)
+		i_error("Backtrace: %s", backtrace);
 	abort();
 }
 
@@ -290,8 +295,12 @@
 
 void i_syslog_panic_handler(const char *fmt, va_list args)
 {
+	const char *backtrace;
+
 	(void)syslog_handler(LOG_CRIT, fmt, args);
-        abort();
+	if (backtrace_get(&backtrace) == 0)
+		i_error("Backtrace: %s", backtrace);
+	abort();
 }
 
 void i_syslog_fatal_handler(int status, const char *fmt, va_list args)
@@ -384,7 +393,11 @@
 static void __attr_noreturn__ __attr_format__(1, 0)
 i_internal_panic_handler(const char *fmt, va_list args)
 {
+	const char *backtrace;
+
 	(void)internal_handler('F', fmt, args);
+	if (backtrace_get(&backtrace) == 0)
+		i_error("Backtrace: %s", backtrace);
         abort();
 }