1 files changed, 117 insertions, 0 deletions
diff --git a/stackdump-on-crash.c b/stackdump-on-crash.c
new file mode 100644
index 0000000..70493ba
--- /dev/null
+++ b/stackdump-on-crash.c
@@ -0,0 +1,117 @@
+/* See LICENSE file for copyright and license details. */
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define UNW_LOCAL_ONLY
+#include <elfutils/libdwfl.h>
+#include <libunwind.h>
+
+
+static const int full_paths = 0;
+
+
+static void
+dump_stack(ucontext_t *ucontext)
+{
+	int saved_errno = errno, lineno;
+	unw_word_t rip;
+	unw_cursor_t cursor;
+	char *debuginfo_path = NULL;
+	Dwarf_Addr ip;
+	Dwfl_Callbacks callbacks;
+	Dwfl *dwfl = NULL;
+	Dwfl_Line *line = NULL;
+	Dwfl_Module *module = NULL;
+	const char *filename = NULL, *p;
+	const char *funcname = NULL;
+	int first = 1;
+
+	if (unw_init_local2(&cursor, ucontext, UNW_INIT_SIGNAL_FRAME))
+		goto out;
+
+	memset(&callbacks, 0, sizeof(callbacks));
+
+	callbacks.find_elf       = dwfl_linux_proc_find_elf;
+	callbacks.find_debuginfo = dwfl_standard_find_debuginfo;
+	callbacks.debuginfo_path = &debuginfo_path;
+
+
+	dwfl = dwfl_begin(&callbacks);
+
+	if (dwfl) {
+		if (dwfl_linux_proc_report(dwfl, getpid()) ||
+		    dwfl_report_end(dwfl, NULL, NULL)) {
+			dwfl_end(dwfl);
+			dwfl = NULL;
+		}
+	}
+
+	do {
+		if (unw_get_reg(&cursor, UNW_REG_IP, &rip))
+			break;
+		ip = (Dwarf_Addr)rip;
+
+		if (dwfl) {
+			module   = dwfl_addrmodule(dwfl, ip);
+			funcname = module ? dwfl_module_addrname(module, ip) : NULL;
+			line     = dwfl_getsrc(dwfl, ip);
+			if (line) {
+				filename = dwfl_lineinfo(line, &(Dwarf_Addr){0},
+				                         &lineno, NULL, NULL, NULL);
+				if (!full_paths && (p = strrchr(filename, '/')))
+					filename = &p[1];
+			}
+		}
+
+		fprintf(stderr, "%s 0x%016"PRIxPTR": %s",
+		        first ? "crashed at" : "        by",
+			(uintptr_t)ip,
+		        funcname ? funcname : "???");
+		first = 0;
+		if (line)
+			fprintf(stderr, " (%s:%i)\n", filename, lineno);
+		else
+			fprintf(stderr, "\n");
+
+	} while (unw_step(&cursor) > 0);
+
+	if (dwfl)
+		dwfl_end(dwfl);
+out:
+	errno = saved_errno;
+}
+
+
+static void
+stack_dumper(int sig, siginfo_t *info, void *ucontext)
+{
+	(void) sig;
+	(void) info;
+	dump_stack(ucontext);
+}
+
+
+int
+main(void)
+{
+	struct sigaction sa;
+
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_sigaction = &stack_dumper;
+	sa.sa_flags = (int)(SA_RESETHAND | SA_SIGINFO);
+
+#if 1
+	{
+		static volatile int *null = NULL;
+		sigaction(SIGSEGV, &sa, NULL);
+		return *null;
+	}
+#else
+	sigaction(SIGABRT, &sa, NULL);
+	abort();
+	return 0;
+#endif
+}