From a09dd4413d1a4ea063173d4822635f41c885f6fe Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Thu, 29 May 2014 22:17:20 +0100 Subject: [PATCH] Running the current tree against my software-single-step-on-x86_64 branch showed some extra assertions I have in place triggering. Turns out my previous change to 'resume' was incomplete, and we mishandle the 'hw_step' / 'step' variable pair. (I swear I had fixed this, but I guess I lost that in some local branch...) Tested on x86_64 Fedora 20. gdb/ 2014-05-29 Pedro Alves * infrun.c (resume): Rename local 'hw_step' to 'entry_step' and make it const. When a single-step decays to a continue, clear 'step', not 'hw_step'. Pass whether the caller wanted to step to user_visible_resume_ptid, not what we ask the target to do. --- gdb/ChangeLog | 8 ++++++++ gdb/infrun.c | 20 +++++++++++++------- 2 files changed, 21 insertions(+), 7 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 156b957b3c..b86f1c790b 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,11 @@ +2014-05-29 Pedro Alves + + * infrun.c (resume): Rename local 'hw_step' to 'entry_step' + and make it const. When a single-step decays to a continue, + clear 'step', not 'hw_step'. Pass whether the caller wanted + to step to user_visible_resume_ptid, not what we ask the + target to do. + 2014-05-29 Pedro Alves * infrun.c (process_event_stop_test, handle_step_into_function) diff --git a/gdb/infrun.c b/gdb/infrun.c index fb0bd54f26..47604c7c50 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -1769,7 +1769,13 @@ resume (int step, enum gdb_signal sig) CORE_ADDR pc = regcache_read_pc (regcache); struct address_space *aspace = get_regcache_aspace (regcache); ptid_t resume_ptid; - int hw_step = step; + /* From here on, this represents the caller's step vs continue + request, while STEP represents what we'll actually request the + target to do. STEP can decay from a step to a continue, if e.g., + we need to implement single-stepping with breakpoints (software + single-step). When deciding whether "set scheduler-locking step" + applies, it's the callers intention that counts. */ + const int entry_step = step; QUIT; @@ -1789,7 +1795,7 @@ resume (int step, enum gdb_signal sig) if (debug_infrun) fprintf_unfiltered (gdb_stdlog, "infrun: resume : clear step\n"); - hw_step = 0; + step = 0; } if (debug_infrun) @@ -1834,7 +1840,7 @@ a command like `return' or `jump' to continue execution.")); step software breakpoint. */ if (use_displaced_stepping (gdbarch) && (tp->control.trap_expected - || (hw_step && gdbarch_software_single_step_p (gdbarch))) + || (step && gdbarch_software_single_step_p (gdbarch))) && sig == GDB_SIGNAL_0 && !current_inferior ()->waiting_for_vfork_done) { @@ -1851,7 +1857,7 @@ a command like `return' or `jump' to continue execution.")); Unless we're calling an inferior function, as in that case we pretend the inferior doesn't run at all. */ if (!tp->control.in_infcall) - set_running (user_visible_resume_ptid (step), 1); + set_running (user_visible_resume_ptid (entry_step), 1); discard_cleanups (old_cleanups); return; } @@ -1861,8 +1867,8 @@ a command like `return' or `jump' to continue execution.")); pc = regcache_read_pc (get_thread_regcache (inferior_ptid)); displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid)); - hw_step = gdbarch_displaced_step_hw_singlestep (gdbarch, - displaced->step_closure); + step = gdbarch_displaced_step_hw_singlestep (gdbarch, + displaced->step_closure); } /* Do we need to do it the hard way, w/temp breakpoints? */ @@ -1924,7 +1930,7 @@ a command like `return' or `jump' to continue execution.")); /* Decide the set of threads to ask the target to resume. Start by assuming everything will be resumed, than narrow the set by applying increasingly restricting conditions. */ - resume_ptid = user_visible_resume_ptid (step); + resume_ptid = user_visible_resume_ptid (entry_step); /* Even if RESUME_PTID is a wildcard, and we end up resuming less (e.g., we might need to step over a breakpoint), from the