From e07d892ce78b2617ca9ed404cfa497b245fce449 Mon Sep 17 00:00:00 2001 From: Mihails Strasuns Date: Mon, 12 Jun 2023 09:49:27 +0200 Subject: [PATCH] gdb, infrun: refactor part of `proceed` into separate function Split the thread resuming code from proceed into new function proceed_resume_thread_checked. Co-Authored-By: Christina Schimpe --- gdb/infrun.c | 155 ++++++++++++++++++++++++++++----------------------- 1 file changed, 86 insertions(+), 69 deletions(-) diff --git a/gdb/infrun.c b/gdb/infrun.c index 5b0257076f0..010fcd7952f 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -3268,6 +3268,89 @@ check_multi_target_resumption (process_stratum_target *resume_target) } } +/* Helper function for `proceed`. Check if thread TP is suitable for + resuming, and, if it is, switch to the thread and call + `keep_going_pass_signal`. If TP is not suitable for resuming then this + function will just return without switching threads. */ + +static void +proceed_resume_thread_checked (thread_info *tp) +{ + if (!tp->inf->has_execution ()) + { + infrun_debug_printf ("[%s] target has no execution", + tp->ptid.to_string ().c_str ()); + return; + } + + if (tp->resumed ()) + { + infrun_debug_printf ("[%s] resumed", + tp->ptid.to_string ().c_str ()); + gdb_assert (tp->executing () || tp->has_pending_waitstatus ()); + return; + } + + if (thread_is_in_step_over_chain (tp)) + { + infrun_debug_printf ("[%s] needs step-over", + tp->ptid.to_string ().c_str ()); + return; + } + + /* When handling a vfork GDB removes all breakpoints from the program + space in which the vfork is being handled, as such we must take care + not to resume any thread other than the vfork parent -- resuming the + vfork parent allows GDB to receive and handle the 'vfork done' + event. */ + if (tp->inf->thread_waiting_for_vfork_done != nullptr) + { + if (target_is_non_stop_p ()) + { + /* For non-stop targets, regardless of whether GDB is using + all-stop or non-stop mode, threads are controlled + individually. + + When a thread is handling a vfork, breakpoints are removed + from the inferior (well, program space in fact), so it is + critical that we don't try to resume any thread other than the + vfork parent. */ + if (tp != tp->inf->thread_waiting_for_vfork_done) + { + infrun_debug_printf ("[%s] thread %s of this inferior is " + "waiting for vfork-done", + tp->ptid.to_string ().c_str (), + tp->inf->thread_waiting_for_vfork_done + ->ptid.to_string ().c_str ()); + return; + } + } + else + { + /* For all-stop targets, when we attempt to resume the inferior, + we will only resume the vfork parent thread, this is handled + in internal_resume_ptid. + + Additionally, we will always be called with the vfork parent + thread as the current thread (TP) thanks to follow_fork, as + such the following assertion should hold. + + Beyond this there is nothing more that needs to be done + here. */ + gdb_assert (tp == tp->inf->thread_waiting_for_vfork_done); + } + } + + infrun_debug_printf ("resuming %s", + tp->ptid.to_string ().c_str ()); + + execution_control_state ecs (tp); + switch_to_thread (tp); + keep_going_pass_signal (&ecs); + if (!ecs.wait_some_more) + error (_("Command aborted.")); +} + /* Basic routine for continuing the program in various fashions. ADDR is the address to resume at, or -1 for resume where stopped. @@ -3456,77 +3539,11 @@ proceed (CORE_ADDR addr, enum gdb_signal siggnal) resume_ptid)) { switch_to_thread_no_regs (tp); - - if (!tp->inf->has_execution ()) - { - infrun_debug_printf ("[%s] target has no execution", - tp->ptid.to_string ().c_str ()); - continue; - } - - if (tp->resumed ()) - { - infrun_debug_printf ("[%s] resumed", - tp->ptid.to_string ().c_str ()); - gdb_assert (tp->executing () || tp->has_pending_waitstatus ()); - continue; - } - - if (thread_is_in_step_over_chain (tp)) - { - infrun_debug_printf ("[%s] needs step-over", - tp->ptid.to_string ().c_str ()); - continue; - } - - /* If a thread of that inferior is waiting for a vfork-done - (for a detached vfork child to exec or exit), breakpoints are - removed. We must not resume any thread of that inferior, other - than the one waiting for the vfork-done. */ - if (tp->inf->thread_waiting_for_vfork_done != nullptr - && tp != tp->inf->thread_waiting_for_vfork_done) - { - infrun_debug_printf ("[%s] another thread of this inferior is " - "waiting for vfork-done", - tp->ptid.to_string ().c_str ()); - continue; - } - - infrun_debug_printf ("resuming %s", - tp->ptid.to_string ().c_str ()); - - execution_control_state ecs (tp); - switch_to_thread (tp); - keep_going_pass_signal (&ecs); - if (!ecs.wait_some_more) - error (_("Command aborted.")); - } - } - else if (!cur_thr->resumed () - && !thread_is_in_step_over_chain (cur_thr)) - { - /* In non-stop mode, if a there exists a thread waiting for a vfork - then only allow that thread to resume (breakpoints are removed - from an inferior when handling a vfork). - - We check target_is_non_stop_p here rather than just checking the - non-stop flag, though these are equivalent (all-stop on a - non-stop target was handled in a previous block, so at this - point, if target_is_non_stop_p then GDB must be running on - non-stop mode). By using target_is_non_stop_p it will be easier - to merge this block with the previous in a later commit. */ - if (!(target_is_non_stop_p () - && cur_thr->inf->thread_waiting_for_vfork_done != nullptr - && cur_thr->inf->thread_waiting_for_vfork_done != cur_thr)) - { - /* The thread wasn't started, and isn't queued, run it now. */ - execution_control_state ecs (cur_thr); - switch_to_thread (cur_thr); - keep_going_pass_signal (&ecs); - if (!ecs.wait_some_more) - error (_("Command aborted.")); + proceed_resume_thread_checked (tp); } } + else + proceed_resume_thread_checked (cur_thr); disable_commit_resumed.reset_and_commit (); } -- 2.30.2