[Bug gdb/17247] New: gdb freezes on multi threaded app (test-case attached)

[Bug gdb/17247] New: gdb freezes on multi threaded app (test-case attached)

[glibc at iamsergio dot de]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

            Bug ID: 17247
           Summary: gdb freezes on multi threaded app (test-case attached)
           Product: gdb
           Version: 7.7
            Status: NEW
          Severity: normal
          Priority: P2
         Component: gdb
          Assignee: unassigned at sourceware dot org
          Reporter: glibc at iamsergio dot de

Created attachment 7741
  --> https://sourceware.org/bugzilla/attachment.cgi?id=7741&action=edit
test-case

Run the attached test-case:

g++ -std=c++11 -lpthread test.cpp -o test
gdb ./test
^C^C^C -> nothing, it's impossible to interrupt


Attaching a second gdb to the first gdb I can get a backtrace:

Thread 1 (Thread 0x7fbe58d58740 (LWP 3540)):
#0  0x00007fbe56c61157 in sigsuspend () from /usr/lib/libc.so.6
#1  0x00000000004a9270 in wait_lwp (lp=lp@entry=0x1edcee0) at linux-nat.c:2314
---Type <return> to continue, or q <return> to quit---
#2  0x00000000004a951e in wait_lwp (lp=lp@entry=0x1edcee0) at linux-nat.c:2370
#3  0x00000000004aad1c in stop_wait_callback (lp=0x1edcee0, data=<optimized
out>) at linux-nat.c:2591
#4  0x00000000004a9df9 in iterate_over_lwps (filter=...,
callback=callback@entry=0x4aacd0 <stop_wait_callback>, data=data@entry=0x0) at
linux-nat.c:1041
#5  0x00000000004ac414 in linux_nat_wait_1 (ops=<optimized out>,
target_options=1, ourstatus=0x7fffc63c4160, ptid=...) at linux-nat.c:3530
#6  linux_nat_wait (ops=<optimized out>, ptid=..., ourstatus=0x7fffc63c4160,
target_options=1) at linux-nat.c:3680
#7  0x00000000004b2676 in thread_db_wait (ops=<optimized out>, ptid=...,
ourstatus=0x7fffc63c4160, options=1) at linux-thread-db.c:1489
#8  0x00000000005e7c3d in delegate_wait (self=<optimized out>, arg1=...,
arg2=<optimized out>, arg3=<optimized out>) at target-delegates.c:116
#9  0x00000000005f5134 in target_wait (ptid=...,
status=status@entry=0x7fffc63c4160, options=options@entry=1) at target.c:2073
#10 0x00000000005b96e9 in fetch_inferior_event
(client_data=client_data@entry=0x0) at infrun.c:2881
#11 0x00000000005cf452 in inferior_event_handler (event_type=INF_REG_EVENT,
client_data=0x0) at inf-loop.c:58
#12 0x00000000005cd671 in process_event () at event-loop.c:340
#13 0x00000000005cda3a in gdb_do_one_event () at event-loop.c:392
#14 0x00000000005cdc8e in start_event_loop () at event-loop.c:429
#15 0x00000000005c7463 in captured_command_loop (data=data@entry=0x0) at
main.c:322
#16 0x00000000005c46aa in catch_errors (func=func@entry=0x5c7450
<captured_command_loop>, func_args=func_args@entry=0x0,
errstring=errstring@entry=0x7990d2 "", mask=mask@entry=RETURN_MASK_ALL) at
exceptions.c:514
#17 0x00000000005c83d6 in captured_main (data=data@entry=0x7fffc63c4450) at
main.c:1178
#18 0x00000000005c46aa in catch_errors (func=func@entry=0x5c7960
<captured_main>, func_args=func_args@entry=0x7fffc63c4450,
errstring=errstring@entry=0x7990d2 "", mask=mask@entry=RETURN_MASK_ALL)
    at exceptions.c:514
#19 0x00000000005c88ab in gdb_main (args=args@entry=0x7fffc63c4450) at
main.c:1186
#20 0x0000000000464dc5 in main (argc=<optimized out>, argv=<optimized out>) at
gdb.c:32

Tested gdb 7.7 and master, on archlinux, kernel 3.14.15, glibc 2.19, gcc 4.9.1,
also tested clang, same bug.

Using x86_64

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[mail at milianw dot de]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Milian Wolff <mail at milianw dot de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mail at milianw dot de

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[mail at milianw dot de]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #1 from Milian Wolff <mail at milianw dot de> ---
Note: Sending SIGCONT to GDB manually makes it work properly again (until it
hangs again eventually). I now do this in a separate console whenever I want to
use gdb:

while true; do killall -s SIGCONT gdb || break; sleep 1; done

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[philip.rebohle@tu-dortmund.de]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Philip Rebohle <philip.rebohle@tu-dortmund.de> changed:

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                 CC|                            |philip.rebohle@tu-dortmund.
                   |                            |de

--- Comment #2 from Philip Rebohle <philip.rebohle@tu-dortmund.de> ---
Same problem here with 7.8.

Thing is that this seems to happen quite randomly. I've run into the problem
with a larger project, sometimes it would hang on thread creation and sometimes
when joining or destructing the threads.

Also, it doesn't seem to hang at all when attaching strace to the gdb process
itself, which doesn't exactly help gathering more information about this
problem...

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[xdje42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Doug Evans <xdje42 at gmail dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |xdje42 at gmail dot com

--- Comment #3 from Doug Evans <xdje42 at gmail dot com> ---
I've tried various things to recreate this but have failed.
Presumably it's a race condition somewhere.

I'm not sure this will help track things down, but it's easy enough to try.

Can the problem be repro'd after adding

set debug infrun 1
set debug lin-lwp 1

to the set of gdb commands before the inferior is run?
If so, attaching the (entire!) output of that to this bug may be helpful.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[mail at milianw dot de]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #4 from Milian Wolff <mail at milianw dot de> ---
Created attachment 7742
  --> https://sourceware.org/bugzilla/attachment.cgi?id=7742&action=edit
gdb debug output

here's the output when running the example compiled test.cpp in GDB with the
debug options enabled

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[kugel at rockbox dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Thomas Martitz <kugel at rockbox dot org> changed:

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                 CC|                            |kugel at rockbox dot org

--- Comment #5 from Thomas Martitz <kugel at rockbox dot org> ---
I can confirm this issue. To me it happens when debugging Geany.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[ideasman42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Campbell Barton <ideasman42 at gmail dot com> changed:

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                 CC|                            |ideasman42 at gmail dot com
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--- Comment #6 from Campbell Barton <ideasman42 at gmail dot com> ---
I recently ran into this on ArchLinux too, since I ran into this debugging
Blender3D application (gdb typically locks up quickly within ~5 or so 'step'
commands, but not instantly)


I tried to look into this further, with the intention of finding which sha1
broke... 

- lldb works fine (just a sanity check that its not the application)
- gdb 7.7.1 works. *
- gdb 7.8 locks up. *

* - Both clean build compiled on my own system, default
configuration,(--prefix=/opt/gdb --with-python=no)

I had troubles with misc build errors attempting to find the git revision that
broke however, all the revisions I managed to build would lock-up, but quite a
few revisions I checked out failed to build.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[net147 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Jonathan Liu <net147 at gmail dot com> changed:

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                 CC|                            |net147 at gmail dot com

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[rggjan at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Jan Rüegg <rggjan at gmail dot com> changed:

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                 CC|                            |rggjan at gmail dot com

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https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #7 from Jan Rüegg <rggjan at gmail dot com> ---
Can we make this a critical priority? This makes gdb pretty much useless for
all multithreaded programs...

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https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #8 from Jan Rüegg <rggjan at gmail dot com> ---
By the way, I can reproduce this on my machine. For me, SIGCONT unfortunately
does not have any effect on the hanging gdb. However, downgrading to 7.7.1
works fine!

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--- Comment #9 from Thomas Martitz <kugel at rockbox dot org> ---
I can confirm that the SIGCONT workaround works for me. Remember that you have
to send it to gdb itself, not the debugee.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[dje at google dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

dje at google dot com changed:

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--- Comment #10 from dje at google dot com ---
Comment on attachment 7742
  --> https://sourceware.org/bugzilla/attachment.cgi?id=7742
gdb debug output

I don't understand this part:

infrun: TARGET_WAITKIND_EXITED
[Inferior 1 (process 4912) exited normally]
infrun: stop_waiting
(gdb) # it hangs here, sending sigcont from another terminal now
(gdb) # again, stuck here - sending another sigcont
(gdb) # and again hung.... one more sigcont
(gdb) q

Did you send a SIGCONT before or after you saw the (gdb) prompt here?
[Just want to confirm how to interpret this.]

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[dje at google dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #11 from dje at google dot com ---
(In reply to Jan Rüegg from comment #7)
> Can we make this a critical priority? This makes gdb pretty much useless for
> all multithreaded programs...

Can anyone recreate this on ubuntu precise or trusty or fedora fc20?
[those are machines I have]

If you can, and can provide the testcase and complete session log,
that'd be great.

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--- Comment #12 from Milian Wolff <mail at milianw dot de> ---
@dje: The first occurrences of these "# ..." lines is when I typed them into
the console when GDB was hung. Later, once GDB becomes unfrozen again, it will
re-print the strings I inserted into the console apparently, which is why
you'll see them again below. So just ignore the (gdb) prompt lines which
include these lines at the end. Only the lines before that are relevant.

Hope that helps.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[nimajnebwild at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[bernd.amend at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Bernd Amend <bernd.amend at gmail dot com> changed:

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--- Comment #13 from Bernd Amend <bernd.amend at gmail dot com> ---
I encountered this issue on Archlinux with gdb 7.8.
I bisected the issue to the commit

commit ed3ef33944c39d9a3cea72b9a7cef3c20f0e3461
Author: Doug Evans <xdje42@gmail.com>
Date:   Sun Feb 9 19:40:01 2014 -0800

    Add Guile as an extension language.

I hope this helps to track down the issue.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[dje at google dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #14 from dje at google dot com ---
(In reply to Bernd Amend from comment #13)
> I encountered this issue on Archlinux with gdb 7.8.
> I bisected the issue to the commit
> 
> commit ed3ef33944c39d9a3cea72b9a7cef3c20f0e3461
> Author: Doug Evans <xdje42@gmail.com>
> Date:   Sun Feb 9 19:40:01 2014 -0800
> 
>     Add Guile as an extension language.
> 
> I hope this helps to track down the issue.

I'm not sure how much help a bisect can be here is the issue is a race
condition.
But you have given me an idea.
Guile uses a separate thread to help with garbage collection, and perhaps a
SIGCHLD is being lost somehow (or whatever).

Question: Does the bug go away if you configure gdb --without-guile?
[Assuming you've got guile installed and the buggy gdb was configured with it.]

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[bernd.amend at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #15 from Bernd Amend <bernd.amend at gmail dot com> ---
The bug goes away if I compile gdb without guile.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[kugel at rockbox dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #16 from Thomas Martitz <kugel at rockbox dot org> ---
I'm affected by this bug but my gdb doesn't know the --without-guile options,
or any other that contains guile (checked with gdb --help | grep guile).

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[philip.rebohle@tu-dortmund.de]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #17 from Philip Rebohle <philip.rebohle@tu-dortmund.de> ---
(In reply to Thomas Martitz from comment #16)
> I'm affected by this bug but my gdb doesn't know the --without-guile
> options, or any other that contains guile

It's a compile-time flag for the 'configure' script, not a runtime option.

I can confirm it works just fine with guile disabled.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[xdje42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #18 from Doug Evans <xdje42 at gmail dot com> ---
(In reply to Philip Rebohle from comment #17)
> (In reply to Thomas Martitz from comment #16)
> > I'm affected by this bug but my gdb doesn't know the --without-guile
> > options, or any other that contains guile
> 
> It's a compile-time flag for the 'configure' script, not a runtime option.
> 
> I can confirm it works just fine with guile disabled.

For those where --without-guile fixes things,
can you record here what version of guile, and what version of libgc you are
using is?
Thanks!

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[xdje42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #19 from Doug Evans <xdje42 at gmail dot com> ---
(In reply to Doug Evans from comment #18)
> (In reply to Philip Rebohle from comment #17)
> > (In reply to Thomas Martitz from comment #16)
> > > I'm affected by this bug but my gdb doesn't know the --without-guile
> > > options, or any other that contains guile
> > 
> > It's a compile-time flag for the 'configure' script, not a runtime option.
> > 
> > I can confirm it works just fine with guile disabled.
> 
> For those where --without-guile fixes things,
> can you record here what version of guile, and what version of libgc you are
> using is?
> Thanks!

Also, can you repeat the experiment 1000 times or so?
[I'm assuming it's easy enough to script.]
There are reports that people are experiencing the issue with 7.7.
7.7 does not have guile.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[kugel at rockbox dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #20 from Thomas Martitz <kugel at rockbox dot org> ---
What is "the experiment"? I experience the problem every single time I start
gdb with a multithreaded application, what information will give you this 1000
times?

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[xdje42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #21 from Doug Evans <xdje42 at gmail dot com> ---
(In reply to Thomas Martitz from comment #20)
> What is "the experiment"? I experience the problem every single time I start
> gdb with a multithreaded application, what information will give you this
> 1000 times?

If it's a race condition independent of guile, then if you get a hang even with
--without-guile, then that is good data to have.  I don't know if it's a race
condition.  It may not be.  At this point I'm still collecting data.

I only picked 1000 as something out of the air.
Even if gdb hangs 10 times in 10 tries that's good data.

Questions:
What system are you on, and which version?
What version of libgc are you using?
What version of guile are you using?
I may need to install it, as I cannot recreate this on the systems I have
access to (ubuntu precise, fedora fc20).

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[xdje42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #22 from Doug Evans <xdje42 at gmail dot com> ---
(In reply to Thomas Martitz from comment #20)
> What is "the experiment"? I experience the problem every single time I start
> gdb with a multithreaded application, what information will give you this
> 1000 times?

btw, can I get repro instructions?
Thanks!

The initial bug report says:

g++ -std=c++11 -lpthread test.cpp -o test
gdb ./test
^C^C^C -> nothing, it's impossible to interrupt

But after doing just "gdb ./test" gdb has not run the program, therefore no
shared libraries have been loaded yet, and therefore gdb does not yet even know
if the program is multithreaded.

Can anyone reproduce this with a non-multithreaded program?
[I suspect the problem is just more easily triggered with a multithreaded
program, but it would be good data to have.]

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[xdje42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #23 from Doug Evans <xdje42 at gmail dot com> ---
(In reply to Doug Evans from comment #22)
> But after doing just "gdb ./test" gdb has not run the program, therefore no
> shared libraries have been loaded yet, and therefore gdb does not yet even
> know if the program is multithreaded.

For pedantic completeness sake,
I guess I should mention that libpthread could be statically linked in.
[Or that one could have one's own thread implementation - I've never used one
so I don't know how well gdb works with it.]

Still, does gdb hang *before* the program is run?

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[philip.rebohle@tu-dortmund.de]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #24 from Philip Rebohle <philip.rebohle@tu-dortmund.de> ---
(In reply to Doug Evans from comment #21)
> Questions:
> What system are you on, and which version?
> What version of libgc are you using?
> What version of guile are you using?

For me, it's the following:
- Arch Linux (everything up to date, as always)
- gc=7.4.2
- guile=2.0.11

Works fine even a thousand times with guile disabled, yes.


(In reply to Doug Evans from comment #23)
> Still, does gdb hang *before* the program is run?

Just tried this with a trivial, single-threaded Hello World program, a few runs
*did* actually lock up before the program was run. Interestingly, ^C works in
that case and gives me a gdb prompt.

Multi-threaded programs will almost always hang on thread creation, which
indeed happens far more often.

Again, this only goes for the guile-enabled version. Without guile, I cannot
reproduce any lockup.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[philip.rebohle@tu-dortmund.de]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #25 from Philip Rebohle <philip.rebohle@tu-dortmund.de> ---
(In reply to Philip Rebohle from comment #24)
> - gc=7.4.2

Just downgraded that one to 7.2d and the lockups are gone.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[xdje42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #26 from Doug Evans <xdje42 at gmail dot com> ---
(In reply to Philip Rebohle from comment #25)
> (In reply to Philip Rebohle from comment #24)
> > - gc=7.4.2
> 
> Just downgraded that one to 7.2d and the lockups are gone.

That's great data.
Thanks!

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[bernd.amend at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #27 from Bernd Amend <bernd.amend at gmail dot com> ---
> Still, does gdb hang *before* the program is run?

I have never seen it.

During the bisecting the different versions behaved differently.
Most of the versions hang directly after entering run.
In this case it was sometimes possible to get a prompt with ^C.

Others versions only if a breakpoint was set and hit. (The released version 7.8
shows this behaviour)
In this case I was unable to reach a gdb prompt with ^C.
Nevertheless even without a breakpoint the application doesn't terminate.
Interestingly if I step thru an application the freeze always appears on the
same position. The position itself changes with the different gdb versions.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[mail at milianw dot de]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #28 from Milian Wolff <mail at milianw dot de> ---
This:

gdb ./test
^C^C^C -> nothing, it's impossible to interrupt

probably was due to a alias which reads "gdb --eval-command="run" --args", I
never saw gdb freeze without running anything.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[chenmulong at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

chenmulong at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |chenmulong at gmail dot com

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[evgeny.grablyk at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Evgeny Grablyk <evgeny.grablyk at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |evgeny.grablyk at gmail dot com

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[evgeny.grablyk at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #29 from Evgeny Grablyk <evgeny.grablyk at gmail dot com> ---
Can confirm that compiling gdb without Guile fixes this for me. Latest Arch
Linux x86_64, GDB-7.8, Guile-2.0.11, gc-7.4.2.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[xdje42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #30 from Doug Evans <xdje42 at gmail dot com> ---
Data point:
If I hack libgc and guile to block SIGCHLD in all the threads they create, I
can make the hang go away.

-->

The sigsuspend that gdb/linux-nat.c calls doesn't receive the SIGCHLD because
another thread receives it.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[xdje42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #31 from Doug Evans <xdje42 at gmail dot com> ---
Can I ask someone to try this patch to see if it fixes the hang?
It does for me, but I'd like to get more confirmation if I can.

If you've changed libgc from 7.4 to 7.2, you'll need to restore back to 7.4.
And if you've built gdb --without-guile, you'll need to rebuild it with guile.
[The point being we want to test with a gdb that experiences the hang.
It would be a good idea to first do a "before" test, just to verify you are
seeing the hang, apply the patch, rebuild, and see if the hang goes away.

Many thanks to any who can try this.

[I'm not sure bugzilla will let me attach the file in this post.
Look for 17247-experiment-1.patch in the Attachments list.]

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[xdje42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Doug Evans <xdje42 at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2014-08-28
           Assignee|unassigned at sourceware dot org   |xdje42 at gmail dot com
     Ever confirmed|0                           |1

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[xdje42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #32 from Doug Evans <xdje42 at gmail dot com> ---
Created attachment 7762
  --> https://sourceware.org/bugzilla/attachment.cgi?id=7762&action=edit
Experimental patch

Tentative fix.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[xdje42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Doug Evans <xdje42 at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Attachment #7762|Experimental patch          |17247-experiment-1.patch
        description|                            |

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[palves at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Pedro Alves <palves at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |palves at redhat dot com

--- Comment #33 from Pedro Alves <palves at redhat dot com> ---
Comment on attachment 7762
  --> https://sourceware.org/bugzilla/attachment.cgi?id=7762
17247-experiment-1.patch

> +#ifdef HAVE_SIGPROCMASK
> +  /* Before we initialize Guile, block SIGCHLD.
> +     This is done so that all threads created during Guile initialization
> +     have SIGCHLD blocked.  PR 17247.  */
> +  sigprocmask (SIG_SETMASK, NULL, &sigset_for_guile);
> +  sigaddset (&sigset_for_guile, SIGCHLD);
> +  sigprocmask (SIG_SETMASK, &sigset_for_guile, NULL);

Using SIG_BLOCK lets this be a single syscall.

> +#endif
> +
>    /* scm_with_guile is the most portable way to initialize Guile.
>       Plus we need to initialize the Guile support while in Guile mode
>       (e.g., called from within a call to scm_with_guile).  */
>    scm_with_guile (call_initialize_gdb_module, NULL);
>  
> +#ifdef HAVE_SIGPROCMASK
> +  /* Undo the blocking of SIGCHLD.  */
> +  sigdelset (&sigset_for_guile, SIGCHLD);
> +  sigprocmask (SIG_SETMASK, &sigset_for_guile, NULL);

This assumes SIGCHLD wasn't blocked before.  Best avoid that, like
in the below pseudo-patch.

+ sigset_t sigchld_set, prev_set;
...
+#ifdef HAVE_SIGPROCMASK
+  /* Before we initialize Guile, make sure SIGCHLD is blocked.
+     This is done so that all threads created during Guile initialization
+     have SIGCHLD blocked.  PR 17247.  */
+  sigemptyset (sigchld_set);
+  sigaddset (&sigchld_set, SIGCHLD);
+  sigprocmask (SIG_BLOCK, &sigchld_set, &prev_set);
+#endif
...
+#ifdef HAVE_SIGPROCMASK
+  /* Restore the previous mask.  */
+  sigprocmask (SIG_SETMASK, &prev_set, NULL);
+#endif

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[corinna at vinschen dot de]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Corinna Vinschen <corinna at vinschen dot de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |corinna at vinschen dot de

--- Comment #34 from Corinna Vinschen <corinna at vinschen dot de> ---
We're encountering a reliable hang on Cygwin GDB 7.8 as well, and Cygwin's
GDB was never built with guile.  It can simply be reproduced like this:

  $ gdb /usr/bin/emacs-w32
  [...]
  (gdb) r
  Starting program: /bin/emacs-w32.exe
  [New Thread 3944.0xfe4]
  [New Thread 3944.0xcb8]
  [New Thread 3944.0xcdc]
  [New Thread 3944.0xf0]
  [New Thread 3944.0x9d4]
  [New Thread 3944.0x9fc]

At this point the GUI program is up and running, for about a second.
Then the cursor stops moving and neither the inferior nor GDB can be
interrupted.  A hard kill of GDB is required.

The previous Cygwin GDB version was 7.6.50, and it doesn't have this
problem.


Corinna

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[jaap at jcz dot nl]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Jaap Crezee <jaap at jcz dot nl> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jaap at jcz dot nl

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[evgeny.grablyk at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #35 from Evgeny Grablyk <evgeny.grablyk at gmail dot com> ---
I've tested GDB with Doug Evans' patch and it seems to be working for me --
I've tested it on a couple Qt apps so far. Patch with corrections proposed by
Pedro Alves also works.

Could it be possible that the Cygwin hang is caused by something else? When
this bug manifests itself on my system, GUI apps never display at all, let
alone run for a second, and killing the hung app leaves GDB operable.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[xdje42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #36 from Doug Evans <xdje42 at gmail dot com> ---
For reference sake, see also PR 17314.

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[xdje42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #37 from Doug Evans <xdje42 at gmail dot com> ---
*** Bug 17185 has been marked as a duplicate of this bug. ***

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[rosslagerwall at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Ross Lagerwall <rosslagerwall at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rosslagerwall at gmail dot com

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[corinna at vinschen dot de]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #38 from Corinna Vinschen <corinna at vinschen dot de> ---
(In reply to Evgeny Grablyk from comment #35)
> I've tested GDB with Doug Evans' patch and it seems to be working for me --
> I've tested it on a couple Qt apps so far. Patch with corrections proposed
> by Pedro Alves also works.
> 
> Could it be possible that the Cygwin hang is caused by something else? When
> this bug manifests itself on my system, GUI apps never display at all, let
> alone run for a second, and killing the hung app leaves GDB operable.

I honestly don't know.  This was the first release of GDB for Cygwin built
with Python support so I suspected this.  However, even after rebuilding
GDB without python support, GDB and the inferior still hang the same way.
For completeness I also tried Doug's patch, but to no avail.

I also attached a second GDB to the hanging GDB and I got this backtrace:

(gdb) thr 1
[Switching to thread 1 (Thread 2832.0x640)]
#0  0x00007ff9efc6c7da in ntdll!ZwWaitForDebugEvent ()
   from /mnt/c/WINDOWS/SYSTEM32/ntdll.dll
(gdb) bt
#0  0x00007ff9efc6c7da in ntdll!ZwWaitForDebugEvent ()
   from /mnt/c/WINDOWS/SYSTEM32/ntdll.dll
#1  0x00007ff9ed31a0c1 in WaitForDebugEvent ()
   from /mnt/c/WINDOWS/system32/KERNELBASE.dll
#2  0x000000010042b9b6 in get_windows_debug_event (pid=-1, ourstatus=0xc3a2c0,
    ops=0x6000bfb80) at /usr/src/debug/gdb-7.8-1/gdb/windows-nat.c:1409
#3  windows_wait (ops=0x6000bfb80, ptid=..., ourstatus=0xc3a2c0, options=0)
    at /usr/src/debug/gdb-7.8-1/gdb/windows-nat.c:1643
#4  0x000000010055734b in delegate_wait (self=<optimized out>, arg1=...,
    arg2=<optimized out>, arg3=0)
    at /usr/src/debug/gdb-7.8-1/gdb/target-delegates.c:60
#5  0x000000010055f2d4 in target_wait (ptid=..., status=status@entry=0xc3a2c0,
    options=options@entry=0) at /usr/src/debug/gdb-7.8-1/gdb/target.c:2107
#6  0x0000000100524efc in wait_for_inferior ()
    at /usr/src/debug/gdb-7.8-1/gdb/infrun.c:2828
#7  0x000000010052517a in proceed (addr=<optimized out>,
    siggnal=siggnal@entry=GDB_SIGNAL_0, step=step@entry=0)
    at /usr/src/debug/gdb-7.8-1/gdb/infrun.c:2388
#8  0x0000000100517fbd in run_command_1 (args=0x0, from_tty=1,
    tbreak_at_main=<optimized out>)
    at /usr/src/debug/gdb-7.8-1/gdb/infcmd.c:630
#9  0x00000001005f789d in execute_command (p=<optimized out>,
    p@entry=0x600038940 "", from_tty=1)
    at /usr/src/debug/gdb-7.8-1/gdb/top.c:462
#10 0x000000010053c206 in command_handler (command=0x600038940 "")
    at /usr/src/debug/gdb-7.8-1/gdb/event-top.c:433
#11 0x000000010053c838 in command_line_handler (rl=<optimized out>)
    at /usr/src/debug/gdb-7.8-1/gdb/event-top.c:630
#12 0x00000003f5285c03 in rl_callback_read_char ()
   from /usr/bin/cygreadline7.dll
#13 0x000000010053c269 in rl_callback_read_char_wrapper (
    client_data=<optimized out>)
    at /usr/src/debug/gdb-7.8-1/gdb/event-top.c:167
#14 0x000000010053ae54 in process_event ()
    at /usr/src/debug/gdb-7.8-1/gdb/event-loop.c:343
#15 0x000000010053b1d7 in gdb_do_one_event ()
    at /usr/src/debug/gdb-7.8-1/gdb/event-loop.c:407
#16 0x000000010053b41e in start_event_loop ()
    at /usr/src/debug/gdb-7.8-1/gdb/event-loop.c:432
#17 0x0000000100534b56 in captured_command_loop (data=data@entry=0x0)
    at /usr/src/debug/gdb-7.8-1/gdb/main.c:302
#18 0x0000000100531c8a in catch_errors (
    func=func@entry=0x100534b40 <captured_command_loop>,
    func_args=func_args@entry=0x0,
    errstring=errstring@entry=0x1007621c3 <__PRETTY_FUNCTION__.13666+257> "",
    mask=mask@entry=RETURN_MASK_ALL)
    at /usr/src/debug/gdb-7.8-1/gdb/exceptions.c:506
#19 0x0000000100535b5b in captured_main (data=data@entry=0xc3aab0)
    at /usr/src/debug/gdb-7.8-1/gdb/main.c:1155
#20 0x0000000100531c8a in catch_errors (
    func=func@entry=0x1005350b0 <captured_main>,
    func_args=func_args@entry=0xc3aab0,
    errstring=errstring@entry=0x1007621c3 <__PRETTY_FUNCTION__.13666+257> "",
    mask=mask@entry=RETURN_MASK_ALL)
    at /usr/src/debug/gdb-7.8-1/gdb/exceptions.c:506
#21 0x0000000100536090 in gdb_main (args=args@entry=0xc3aab0)
    at /usr/src/debug/gdb-7.8-1/gdb/main.c:1163
#22 0x00000001006e8e58 in main (argc=2, argv=0xc3ab30)
    at /usr/src/debug/gdb-7.8-1/gdb/gdb.c:33



Corinna

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[cvs-commit at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #39 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "gdb and binutils".

The branch, master has been updated
       via  92d8d229d9a310ebfcfc13bf4a75a286c1add1ac (commit)
      from  837405970476d31d6b4d7774e2c914fdfa7a9930 (commit)

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https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=92d8d229d9a310ebfcfc13bf4a75a286c1add1ac

commit 92d8d229d9a310ebfcfc13bf4a75a286c1add1ac
Author: Doug Evans <xdje42@gmail.com>
Date:   Mon Sep 8 22:45:34 2014 -0700

    Fix for PR 17247: Block SIGCHLD while initializing Guile.

    The problem here is that if a thread other than gdb's main thread
    gets a SIGCHLD (it's an asynchronous signal so the kernel will
    essentially pick a random thread) then gdb will hang if it is
    in sigsuspend when the SIGCHLD is delivered.  The other thread
    will see the signal and the sigsuspend won't "wake up".

    Guile and libgc should be blocking SIGCHLD in their threads,
    but we need to work with Guile 2.0 and libgc 7.4.
    The problem first shows up in libgc 7.4 because it is the first
    release that enables multiple marker threads by default.

    gdb/ChangeLog:

        PR 17247
        * guile.c: #include <signal.h>.
        (_initialize_guile): Block SIGCHLD while initializing Guile.

        Replaces the following, which is reverted.

        2014-07-26  Doug Evans  <xdje42@gmail.com>

        PR 17185
        * configure.ac: Add check for header gc/gc.h.
        Add check for function setenv.
        * configure: Regenerate.
        * config.in: Regenerate.
        * guile/guile.c (_initialize_guile): Add workaround for libgc 7.4.0.

-----------------------------------------------------------------------

Summary of changes:
 gdb/ChangeLog     |   17 +++++++++++++
 gdb/config.in     |    6 ----
 gdb/configure     |   26 --------------------
 gdb/configure.ac  |    5 ----
 gdb/guile/guile.c |   67 ++++++++++++++++++++++++++++------------------------
 5 files changed, 53 insertions(+), 68 deletions(-)

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[cvs-commit at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #40 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "gdb and binutils".

The branch, gdb-7.8-branch has been updated
       via  0df33300929f9b54ddcf040f9b1fe69c1a88304b (commit)
      from  0fefcb3282480d15a66fbf5daf65ef25adee9e76 (commit)

Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
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- Log -----------------------------------------------------------------
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=0df33300929f9b54ddcf040f9b1fe69c1a88304b

commit 0df33300929f9b54ddcf040f9b1fe69c1a88304b
Author: Doug Evans <xdje42@gmail.com>
Date:   Tue Sep 9 21:42:20 2014 -0700

    Fix for PR 17247: Block SIGCHLD while initializing Guile.

    The problem here is that if a thread other than gdb's main thread
    gets a SIGCHLD (it's an asynchronous signal so the kernel will
    essentially pick a random thread) then gdb will hang if it is
    in sigsuspend when the SIGCHLD is delivered.  The other thread
    will see the signal and the sigsuspend won't "wake up".

    Guile and libgc should be blocking SIGCHLD in their threads,
    but we need to work with Guile 2.0 and libgc 7.4.
    The problem first shows up in libgc 7.4 because it is the first
    release that enables multiple marker threads by default.

    gdb/ChangeLog:

            PR 17247
            * guile.c: #include <signal.h>.
            (_initialize_guile): Block SIGCHLD while initializing Guile.

            Replaces the following, which is reverted.

            2014-07-26  Doug Evans  <xdje42@gmail.com>

            PR 17185
            * configure.ac: Add check for header gc/gc.h.
            Add check for function setenv.
            * configure: Regenerate.
            * config.in: Regenerate.
            * guile/guile.c (_initialize_guile): Add workaround for libgc
7.4.0.

-----------------------------------------------------------------------

Summary of changes:
 gdb/ChangeLog     |   17 +++++++++++++
 gdb/config.in     |    6 ----
 gdb/configure     |   26 --------------------
 gdb/configure.ac  |    5 ----
 gdb/guile/guile.c |   67 ++++++++++++++++++++++++++++------------------------
 5 files changed, 53 insertions(+), 68 deletions(-)

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[xdje42 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Doug Evans <xdje42 at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #41 from Doug Evans <xdje42 at gmail dot com> ---
patch committed to both trunk and 7.8 branch

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[kbrown at cornell dot edu]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Ken Brown <kbrown at cornell dot edu> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kbrown at cornell dot edu

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[cvs-commit at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

--- Comment #42 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "gdb and binutils".

The annotated tag, gdb-7.8.1-release has been created
        at  60cd8f8e7f38daf7d59e82b9fb3b8840a3a714c9 (tag)
   tagging  21de41c04a26bb04f2e827d35fd48c991fa991b1 (commit)
  replaces  gdb-7.8-release
 tagged by  Joel Brobecker
        on  Wed Oct 29 12:47:08 2014 -0700

- Log -----------------------------------------------------------------
GDB 7.8.1 Release.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1

iEYEABECAAYFAlRRRDwACgkQku2wS/8yXPNA3gCgmaBkksiuRbHoYAudWcZYwiJ4
upIAoI2vGr/6e6CNHxIinVYQ2IJCY/4V
=wgXR
-----END PGP SIGNATURE-----

Doug Evans (3):
      Fix for PR 17247: Block SIGCHLD while initializing Guile.
      PR guile/17367
      PR python/17364

Eli Zaretskii (1):
      Avoid compiler warnings about incomplete parameter types.

GDB Administrator (92):
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in
      Automatic date update in version.in

Jan Kratochvil (4):
      Fix incorrect placement of two Intel gdb/NEWS items
      Fix 'gcore' with exited threads
      Fix crash on Python frame filters with unreadable arg
      Fix regression for Linux vDSO in GDB (PR gdb/17407).

Joel Brobecker (5):
      Document the GDB 7.8 release in gdb/ChangeLog
      Bump GDB version number to 7.8.0.DATE-cvs.
      Add "frame.h" #include in gdbarch.h.
      state->dr_control_mirror == 0 failed assertion in gdbserver on Windows XP
      Set GDB version number to 7.8.1.

Pedro Alves (9):
      testsuite: refactor spawn and wait for attach
      gdb/17347 - Regression: GDB stopped on run with attached process
      Aarch64: Make CPSR a 32-bit register again in the target description
      Make common code handle target_terminal_* idempotency
      PR gdb/17472: With annotations, input while executing in the foreground
crashes readline/GDB
      PR gdb/17300: Input after "c -a" crashes readline/GDB
      PR gdb/17471: Repeating a background command makes it foreground
      PR python/17372 - Python hangs when displaying help()
      PR 17408 - assertion failure in switch_back_to_stepped_thread

Siva Chandra (1):
      Fix xmethod Python so that it works with Python3.

Yao Qi (2):
      Fix build/17104
      Remove workaround to libbabeltrace 1.1.0 issue

-----------------------------------------------------------------------

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[dianeBerlusconi at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

Roman Jay Almaza <dianeBerlusconi at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dianeBerlusconi at gmail dot com

--- Comment #43 from Roman Jay Almaza <dianeBerlusconi at gmail dot com> ---

What is "the experiment"? I experience the problem every single time I start
gdb with a multithreaded application, what information will give you this 1000
times?
https://www.artexproductions.com

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[bap.fayol at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

yaoltreza <bap.fayol at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bap.fayol at gmail dot com

--- Comment #44 from yaoltreza <bap.fayol at gmail dot com> ---
thank you for the all the insights that you share here.
https://couvreur-rouen.com

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[jameszen29 at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

jameszen <jameszen29 at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jameszen29 at gmail dot com

--- Comment #45 from jameszen <jameszen29 at gmail dot com> ---

How can do it? Can you share with me>
It's may idea https://fallguys3.com free

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[Bug gdb/17247] gdb freezes on multi threaded app (test-case attached)

[nimajnebwild at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=17247

nimajnebwild at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|nimajnebwild at gmail dot com      |

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