From 7cebff0d0374d2ffd94f3bffe6ea922bb9091563 Mon Sep 17 00:00:00 2001 From: Pavel Dovgalyuk Date: Mon, 29 Mar 2021 10:59:25 +0300 Subject: [PATCH] replay: fix recursive checkpoints Record/replay uses checkpoints to synchronize the execution of the threads and timers. Hardware events such as BH are processed at the checkpoints too. Event processing can cause refreshing the virtual timers and calling the icount-related functions, that also use checkpoints. This patch prevents recursive processing of such checkpoints, because they have their own records in the log and should be processed later. Signed-off-by: Pavel Dovgalyuk Message-Id: <161700476500.1140362.10108444973730452257.stgit@pasha-ThinkPad-X280> Signed-off-by: Paolo Bonzini --- replay/replay.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/replay/replay.c b/replay/replay.c index c806fec69a..6df2abc18c 100644 --- a/replay/replay.c +++ b/replay/replay.c @@ -180,12 +180,13 @@ bool replay_checkpoint(ReplayCheckpoint checkpoint) } if (in_checkpoint) { - /* If we are already in checkpoint, then there is no need - for additional synchronization. + /* Recursion occurs when HW event modifies timers. - Timer modification may invoke the checkpoint and - proceed to recursion. */ - return true; + Prevent performing icount warp in this case and + wait for another invocation of the checkpoint. + */ + g_assert(replay_mode == REPLAY_MODE_PLAY); + return false; } in_checkpoint = true;