diff --git a/port/stack_trace.cc b/port/stack_trace.cc index 51d136b04..ad648d3bc 100644 --- a/port/stack_trace.cc +++ b/port/stack_trace.cc @@ -141,20 +141,30 @@ void PrintStack(void* frames[], int num_frames) { } void PrintStack(int first_frames_to_skip) { -#if defined(ROCKSDB_DLL) && defined(OS_LINUX) - // LIB_MODE=shared build produces mediocre information from the above - // backtrace+addr2line stack trace method. Try to use GDB in that case, but - // only on Linux where we know how to attach to a particular thread. - bool linux_dll = true; + // Default to getting stack traces with GDB, at least on Linux where we + // know how to attach to a particular thread. + // + // * Address space layout randomization (ASLR) interferes with getting good + // stack information from backtrace+addr2line. This is more likely to show + // up with LIB_MODE=shared builds (when kernel.randomize_va_space >= 1) + // but can also show up with LIB_MODE=static builds ((when + // kernel.randomize_va_space == 2). + // * It doesn't appear easy to detect when ASLR is in use. + // * With DEBUG_LEVEL < 2, backtrace() can skip frames that are not skipped + // in GDB. +#if defined(OS_LINUX) + // Default true, override with ROCKSDB_BACKTRACE_STACK=1 + bool gdb_stack_trace = getenv("ROCKSDB_BACKTRACE_STACK") == nullptr; #else - bool linux_dll = false; + // Default false, override with ROCKSDB_GDB_STACK=1 + bool gdb_stack_trace = getenv("ROCKSDB_GDB_STACK") != nullptr; #endif // Also support invoking interactive debugger on stack trace, with this // envvar set to non-empty char* debug_env = getenv("ROCKSDB_DEBUG"); bool debug = debug_env != nullptr && strlen(debug_env) > 0; - if (linux_dll || debug) { + if (gdb_stack_trace || debug) { // Allow ouside debugger to attach, even with Yama security restrictions #ifdef PR_SET_PTRACER_ANY (void)prctl(PR_SET_PTRACER, PR_SET_PTRACER_ANY, 0, 0, 0);