From 91baf43fa70827325272667c8e7a86c553c767dc Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Thu, 19 Mar 2015 16:51:09 +0000 Subject: [PATCH] gdbserver/Linux: unbreak non-stop The previous change added an assertion that is catching yet another bug in count_events_callback/select_event_lwp_callback: (gdb) PASS: gdb.mi/mi-nonstop.exp: interrupted mi_expect_interrupt: expecting: \*stopped,(reason="signal-received",signal-name="0",signal-meaning="Signal 0"|reason="signal-received",signal-name="SIGINT",signal-meaning="Interrupt")[^ ]* /home/pedro/gdb/mygit/src/gdb/gdbserver/linux-low.c:2329: A problem internal to GDBserver has been detected. select_event_lwp: Assertion `num_events > 0' failed. =thread-group-exited,id="i1" Certainly select_event_lwp_callback should always at least find one event, as it's only called because an event triggered (though we may have more than one: the point of the function is randomly picking one). An LWP that GDB previously asked to continue/step (thus is resumed) and gets a vCont;t request ends up with last_resume_kind == resume_stop. These functions in gdbserver used to filter out events that weren't going to be reported to GDB; I think the last_resume_kind kind check used to make sense at that point, but it no longer does. gdb/gdbserver/ChangeLog: 2015-03-19 Pedro Alves * linux-low.c (count_events_callback, select_event_lwp_callback): No longer check whether the thread has resume_stop as last resume kind. --- gdb/gdbserver/ChangeLog | 6 ++++++ gdb/gdbserver/linux-low.c | 4 +--- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index df8f9ab888c..0383e67c59a 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,9 @@ +2015-03-19 Pedro Alves + + * linux-low.c (count_events_callback, select_event_lwp_callback): + No longer check whether the thread has resume_stop as last resume + kind. + 2015-03-19 Pedro Alves * linux-low.c (count_events_callback, select_event_lwp_callback): diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c index e53e0fc187d..2b988ec1361 100644 --- a/gdb/gdbserver/linux-low.c +++ b/gdb/gdbserver/linux-low.c @@ -2245,7 +2245,6 @@ count_events_callback (struct inferior_list_entry *entry, void *data) /* Count only resumed LWPs that have an event pending. */ if (thread->last_status.kind == TARGET_WAITKIND_IGNORE - && thread->last_resume_kind != resume_stop && lp->status_pending_p) (*count)++; @@ -2280,8 +2279,7 @@ select_event_lwp_callback (struct inferior_list_entry *entry, void *data) gdb_assert (selector != NULL); /* Select only resumed LWPs that have an event pending. */ - if (thread->last_resume_kind != resume_stop - && thread->last_status.kind == TARGET_WAITKIND_IGNORE + if (thread->last_status.kind == TARGET_WAITKIND_IGNORE && lp->status_pending_p) if ((*selector)-- == 0) return 1; -- 2.30.2