diff --git a/debuggerd/debuggerd_test.cpp b/debuggerd/debuggerd_test.cpp index 388facb45..bea8b43ca 100644 --- a/debuggerd/debuggerd_test.cpp +++ b/debuggerd/debuggerd_test.cpp @@ -37,6 +37,7 @@ #include #include #include +#include #include #include #include @@ -1053,3 +1054,42 @@ TEST(tombstoned, intercept_any) { ASSERT_TRUE(android::base::ReadFully(output_fd.get(), outbuf, sizeof(outbuf))); ASSERT_STREQ("any", outbuf); } + +TEST(tombstoned, interceptless_backtrace) { + // Generate 50 backtraces, and then check to see that we haven't created 50 new tombstones. + auto get_tombstone_timestamps = []() -> std::map { + std::map result; + for (int i = 0; i < 99; ++i) { + std::string path = android::base::StringPrintf("/data/tombstones/tombstone_%02d", i); + struct stat st; + if (stat(path.c_str(), &st) == 0) { + result[i] = st.st_mtim.tv_sec; + } + } + return result; + }; + + auto before = get_tombstone_timestamps(); + for (int i = 0; i < 50; ++i) { + raise_debugger_signal(kDebuggerdNativeBacktrace); + } + auto after = get_tombstone_timestamps(); + + int diff = 0; + for (int i = 0; i < 99; ++i) { + if (after.count(i) == 0) { + continue; + } + if (before.count(i) == 0) { + ++diff; + continue; + } + if (before[i] != after[i]) { + ++diff; + } + } + + // We can't be sure that nothing's crash looping in the background. + // This should be good enough, though... + ASSERT_LT(diff, 10) << "too many new tombstones; is something crashing in the background?"; +} diff --git a/debuggerd/tombstoned/tombstoned.cpp b/debuggerd/tombstoned/tombstoned.cpp index 15ae40624..ad9206702 100644 --- a/debuggerd/tombstoned/tombstoned.cpp +++ b/debuggerd/tombstoned/tombstoned.cpp @@ -212,8 +212,13 @@ static void perform_request(Crash* crash) { bool intercepted = intercept_manager->GetIntercept(crash->crash_pid, crash->crash_type, &output_fd); if (!intercepted) { - std::tie(crash->crash_tombstone_path, output_fd) = CrashQueue::for_crash(crash)->get_output(); - crash->crash_tombstone_fd.reset(dup(output_fd.get())); + if (crash->crash_type == kDebuggerdNativeBacktrace) { + // Don't generate tombstones for native backtrace requests. + output_fd.reset(open("/dev/null", O_WRONLY | O_CLOEXEC)); + } else { + std::tie(crash->crash_tombstone_path, output_fd) = CrashQueue::for_crash(crash)->get_output(); + crash->crash_tombstone_fd.reset(dup(output_fd.get())); + } } TombstonedCrashPacket response = {