From 982263ce714ffcc4c7c41a7b255bd29e093912fe Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Wed, 5 Apr 2017 11:05:28 +0100 Subject: [PATCH] replay: assert time only goes forward MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If we find ourselves trying to add an event to the log where time has gone backwards it is because a vCPU event has occurred and the main-loop is not yet aware of time moving forward. This should not happen and if it does its better to fail early than generate a log that will have weird behaviour. Signed-off-by: Alex Bennée --- replay/replay-internal.c | 4 ++++ replay/replay.c | 4 ++++ 2 files changed, 8 insertions(+) diff --git a/replay/replay-internal.c b/replay/replay-internal.c index bea7b4aa6b..fca8514012 100644 --- a/replay/replay-internal.c +++ b/replay/replay-internal.c @@ -195,6 +195,10 @@ void replay_save_instructions(void) if (replay_file && replay_mode == REPLAY_MODE_RECORD) { replay_mutex_lock(); int diff = (int)(replay_get_current_step() - replay_state.current_step); + + /* Time can only go forward */ + assert(diff >= 0); + if (diff > 0) { replay_put_event(EVENT_INSTRUCTION); replay_put_dword(diff); diff --git a/replay/replay.c b/replay/replay.c index 9e0724e756..f810628cac 100644 --- a/replay/replay.c +++ b/replay/replay.c @@ -84,6 +84,10 @@ void replay_account_executed_instructions(void) if (replay_state.instructions_count > 0) { int count = (int)(replay_get_current_step() - replay_state.current_step); + + /* Time can only go forward */ + assert(count >= 0); + replay_state.instructions_count -= count; replay_state.current_step += count; if (replay_state.instructions_count == 0) {