From dc14e88e07ba3c0d8b7ef1f3183240d6f6428be3 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Sat, 2 Aug 2014 00:54:15 +0000 Subject: [PATCH] re PR other/61895 (libbacktrace crashes with bus error with empty file argv[0]) PR other/61895 runtime: Ignore small argv[0] file for backtrace. Reportedly in some cases Docker starts processes with argv[0] pointing to an empty file. That would cause libgo to pass that empty file to libbacktrace, which would then fail to do any backtraces. Everything should work fine if libbacktrace falls back to /proc/self/exe. This patch to libgo works around the problem by ignoring argv[0] if it is a small file, or if stat fails. This is not a perfect fix but it's an unusual problem. From-SVN: r213513 --- libgo/runtime/go-caller.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/libgo/runtime/go-caller.c b/libgo/runtime/go-caller.c index a5c687d00f49..7fcdf2021d39 100644 --- a/libgo/runtime/go-caller.c +++ b/libgo/runtime/go-caller.c @@ -7,6 +7,9 @@ /* Implement runtime.Caller. */ #include +#include +#include +#include #include "backtrace.h" @@ -99,6 +102,7 @@ __go_get_backtrace_state () if (back_state == NULL) { const char *filename; + struct stat s; filename = (const char *) runtime_progname (); @@ -108,6 +112,14 @@ __go_get_backtrace_state () if (__builtin_strchr (filename, '/') == NULL) filename = NULL; + /* If the file is small, then it's not the real executable. + This is specifically to deal with Docker, which uses a bogus + argv[0] (http://gcc.gnu.org/PR61895). It would be nice to + have a better check for whether this file is the real + executable. */ + if (stat (filename, &s) < 0 || s.st_size < 1024) + filename = NULL; + back_state = backtrace_create_state (filename, 1, error_callback, NULL); } runtime_unlock (&back_state_lock); -- 2.47.3