From: Pedro Alves <palves@redhat.com>
To: gdb-patches@sourceware.org
Subject: [PATCH 9/9] Non-stop + software single-step archs: don't force displaced-stepping for all single-steps
Date: Fri, 26 Sep 2014 00:40:00 -0000 [thread overview]
Message-ID: <1411691982-10744-10-git-send-email-palves@redhat.com> (raw)
In-Reply-To: <1411691982-10744-1-git-send-email-palves@redhat.com>
This finally reverts this bit of commit 929dfd4f:
2009-07-31 Pedro Alves <pedro@codesourcery.com>
Julian Brown <julian@codesourcery.com>
...
(resume): If this is a software single-stepping arch, and
displaced-stepping is enabled, use it for all single-step
requests.
...
That means that in non-stop (or really displaced-stepping) mode, on
software single-step archs - even those that only use sss breakpoints
to deal with atomic sequences, like PPC - if we have more than one
thread single-stepping, we'll always serialize the threads'
single-steps, as only one thread may be displaced stepping at a given
time, because there's only one scratch pad.
We originally did that because GDB didn't support having multiple
threads software-single-stepping simultaneously. The previous patches
fixed that limitation, so we can now finally revert this too.
Tested on:
- x86_64 Fedora 20, on top of the 'software single-step on x86'
series.
- PPC64 Fedora 18 (installs gdbarch_software_single_step hook to
deal with atomic sequences).
gdb/
2014-09-25 Pedro Alves <palves@redhat.com>
* infrun.c (resume): Don't force displaced-stepping for all
single-steps on software single-stepping archs.
---
gdb/infrun.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/gdb/infrun.c b/gdb/infrun.c
index 4ff5b07..e51bc7c 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -1846,8 +1846,7 @@ a command like `return' or `jump' to continue execution."));
event, displaced stepping breaks the vfork child similarly as single
step software breakpoint. */
if (use_displaced_stepping (gdbarch)
- && (tp->control.trap_expected
- || (step && gdbarch_software_single_step_p (gdbarch)))
+ && tp->control.trap_expected
&& sig == GDB_SIGNAL_0
&& !current_inferior ()->waiting_for_vfork_done)
{
--
1.9.3
next prev parent reply other threads:[~2014-09-26 0:39 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-26 0:39 [PATCH 0/9] software single-step support rework, fix limitations Pedro Alves
2014-09-26 0:39 ` [PATCH 1/9] Decide whether we may have removed breakpoints based on step_over_info Pedro Alves
2014-09-28 12:52 ` Yao Qi
2014-10-02 18:05 ` Pedro Alves
2014-10-06 1:06 ` Yao Qi
2014-10-06 8:42 ` Pedro Alves
2014-09-26 0:39 ` [PATCH 2/9] Rewrite non-continuable watchpoints handling Pedro Alves
2014-09-26 0:40 ` [PATCH 4/9] Remove deprecated_insert_raw_breakpoint and friends Pedro Alves
2014-09-26 0:40 ` [PATCH 3/9] Put single-step breakpoints on the bp_location chain Pedro Alves
2014-09-28 12:36 ` Yao Qi
2014-09-30 13:01 ` Pedro Alves
2014-09-30 13:15 ` Pedro Alves
2014-09-29 6:33 ` Yao Qi
2014-10-02 17:55 ` Pedro Alves
2014-09-26 0:40 ` [PATCH 5/9] Switch back to stepped thread: clear step-over info Pedro Alves
2014-09-30 16:33 ` Pedro Alves
2014-09-26 0:40 ` [PATCH 8/9] Make single-step breakpoints be per-thread Pedro Alves
2014-09-26 0:40 ` Pedro Alves [this message]
2014-09-26 1:18 ` [PATCH 6/9] thread.c: cleanup breakpoint deletion Pedro Alves
2014-09-26 1:36 ` [PATCH 7/9] infrun.c: add for_each_just_stopped_thread Pedro Alves
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