Well, I got *something* now, but I'm not entirely sure where to go from
here.
The core dump is here:
https://drive.google.com/file/d/1ywlMhK6GJRG5lRbGmg12-k04j9L4HJer/view?usp=sharing
And here's the terminal log from that session, after recompiling with
debugging enabled:
aaron@aaron-M6800:~$ non-mixer &
[2] 6332
aaron@aaron-M6800:~$ The Non-Mixer 1.2.0 -- Copyright (c) 2008-2013
Jonathan Moore Liles
[non-mixer] ../nonlib/OSC/Endpoint.C:202 init(): Creating OSC server
[non-mixer] ../mixer/src/Plugin_Module.C:257 discover_thread():
Discovering plugins in the background
WARNING: LADSPA_PATH environment variable not set
Assuming /usr/lib/ladspa:/usr/local/lib/ladspa
OSC=osc.udp://aaron-M6800:16412/
[non-mixer] ../mixer/src/main.C:310 main(): Running UI...
[non-mixer] ../nonlib/OSC/Endpoint.C:1156 osc_thread(): OSC Thread running
X_ChangeProperty: BadValue (integer parameter out of range for
operation) 0x0
WARNING: Could not open path /usr/local/lib/ladspa/
10 plugins found in 5 libraries
WARNING: LADSPA_RDF_PATH environment variable not set
Assuming /usr/share/ladspa/rdf:/usr/local/share/ladspa/rdf
WARNING: Could not open path /usr/local/share/ladspa/rdf/
gdb `which non-mixer` `pidof non-mixer`
GNU gdb (Ubuntu 9.2-0ubuntu1~20.04) 9.2
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from /usr/local/bin/non-mixer...
Attaching to program: /usr/local/bin/non-mixer, process 6332
Could not attach to process. If your uid matches the uid of the target
process, check the setting of /proc/sys/kernel/yama/ptrace_scope, or try
again as the root user. For more details, see /etc/sysctl.d/10-ptrace.conf
ptrace: Operation not permitted.
/home/aaron/6332: No such file or directory.
(gdb) set logging on
Copying output to gdb.txt.
Copying debug output to gdb.txt.
(gdb) thread apply all bt full
(gdb) [non-mixer] ../mixer/src/Mixer.C:230 cb_menu(): Picked &Mixer/&Add
Strip
[non-mixer] ../mixer/src/Module.C:606 chain(): Module Controller already
belongs to chain NULL
Cannot lock down 82280346 byte memory area (Cannot allocate memory)
Cannot use real-time scheduling (RR/5)(1: Operation not permitted)
JackClient::AcquireSelfRealTime error
Cannot lock down 82280346 byte memory area (Cannot allocate memory)
[non-mixer] ../mixer/src/Chain.C:375 configure_ports(): required_buffers = 0
Cannot use real-time scheduling (RR/5)(1: Operation not permitted)
JackClient::AcquireSelfRealTime error
[non-mixer] ../mixer/src/Module.C:595 chain(): Adding module (null) in
to chain Unnamed
[non-mixer] ../mixer/src/Module.C:595 chain(): Adding module Controller
in to chain Unnamed
[non-mixer] ../mixer/src/Module.C:595 chain(): Adding module Controller
in to chain Unnamed
[non-mixer] ../mixer/src/Module.C:595 chain(): Adding module Controller
in to chain Unnamed
[non-mixer] ../mixer/src/Module.C:595 chain(): Adding module Meter
Indicator in to chain Unnamed
[non-mixer] ../mixer/src/Module.C:595 chain(): Adding module JACK in to
chain Unnamed
[non-mixer] ../nonlib/JACK/Port.C:193 activate(): Activating port name in-1
[non-mixer] ../nonlib/JACK/Port.C:207 activate(): Port = 0x5
[non-mixer] ../mixer/src/Mixer.C:1155 auto_connect(): Full auto-connect
cycle
[non-mixer] ../mixer/src/Module.C:606 chain(): Module JACK already
belongs to chain Unnamed
[non-mixer] ../mixer/src/Mixer_Strip.C:440 handle_module_added():
Connecting controls to default module "JACK"
[non-mixer] ../mixer/src/Chain.C:375 configure_ports(): required_buffers = 1
[non-mixer] ../mixer/src/Chain.C:629 insert(): Module "JACK" has 0:1
audio and 2:0 control ports
[non-mixer] ../mixer/src/Module.C:595 chain(): Adding module Gain in to
chain Unnamed
[non-mixer] ../mixer/src/Module.C:606 chain(): Module Gain already
belongs to chain Unnamed
[non-mixer] ../mixer/src/Mixer_Strip.C:440 handle_module_added():
Connecting controls to default module "Gain"
[non-mixer] ../mixer/src/Chain.C:375 configure_ports(): required_buffers = 1
[non-mixer] ../mixer/src/Chain.C:629 insert(): Module "Gain" has 1:1
audio and 2:0 control ports
[non-mixer] ../mixer/src/Module.C:595 chain(): Adding module Meter in to
chain Unnamed
[non-mixer] ../mixer/src/Mixer_Strip.C:440 handle_module_added():
Connecting controls to default module "Meter"
[non-mixer] ../mixer/src/Chain.C:375 configure_ports(): required_buffers = 1
[non-mixer] ../mixer/src/Chain.C:629 insert(): Module "Meter" has 1:1
audio and 0:1 control ports
[non-mixer] ../mixer/src/Module.C:595 chain(): Adding module JACK in to
chain Unnamed
[non-mixer] ../mixer/src/Module.C:606 chain(): Module JACK already
belongs to chain Unnamed
[non-mixer] ../nonlib/JACK/Port.C:193 activate(): Activating port name out-1
[non-mixer] ../nonlib/JACK/Port.C:207 activate(): Port = 0x6
[non-mixer] ../mixer/src/Mixer_Strip.C:440 handle_module_added():
Connecting controls to default module "JACK"
[non-mixer] ../mixer/src/Chain.C:375 configure_ports(): required_buffers = 1
[non-mixer] ../mixer/src/Chain.C:629 insert(): Module "JACK" has 1:0
audio and 2:0 control ports
[non-mixer] ../mixer/src/Chain.C:375 configure_ports(): required_buffers = 1
[non-mixer] ../mixer/src/Mixer.C:755 add(): Add mixer strip "Unnamed"
[non-mixer] ../mixer/src/Module.C:843 insert_menu_cb(): picked = Mono Pan
[non-mixer] ../mixer/src/Module.C:595 chain(): Adding module Mono Pan in
to chain Unnamed
[non-mixer] ../nonlib/JACK/Port.C:193 activate(): Activating port name out-2
[non-mixer] ../nonlib/JACK/Port.C:207 activate(): Port = 0x7
[non-mixer] ../mixer/src/Chain.C:375 configure_ports(): required_buffers = 2
[non-mixer] ../mixer/src/Chain.C:629 insert(): Module "Mono Pan" has 1:2
audio and 1:0 control ports
[non-mixer] ../mixer/src/Module.C:1397 command_open_parameter_editor():
Opening module parameters for "Mono Pan"
[non-mixer] ../mixer/src/Module_Parameter_Editor.C:621 menu_cb(): Bind
[non-mixer] ../mixer/src/Module.C:595 chain(): Adding module Pan in to
chain Unnamed
[non-mixer] ../mixer/src/Chain.C:375 configure_ports(): required_buffers = 2
[non-mixer] ../mixer/src/Chain.C:308 remove(): Removing controller
module from chain
thread apply all bt full
(gdb) quit
[2]+ Segmentation fault (core dumped) non-mixer
aaron@aaron-M6800:~$ gdb `which non-mixer` core
GNU gdb (Ubuntu 9.2-0ubuntu1~20.04) 9.2
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from /usr/local/bin/non-mixer...
[New LWP 6362]
[New LWP 6332]
[New LWP 6334]
[New LWP 6361]
[New LWP 6360]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `non-mixer'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00005562fe5421ff in Chain::process (this=0x5562ff9c0660,
nframes=1024) at ../mixer/src/Chain.C:906
906 m->process( nframes );
[Current thread is 1 (Thread 0x7f1c023f4700 (LWP 6362))]
(gdb) quit
aaron@aaron-M6800:~$
gdb.txt is present but still empty after all that.
The seemingly relevant sections of code are Chain.C:308, which includes
the last debug message as I removed the control:
void
Chain::remove ( Controller_Module *m )
{
DMESSAGE( "Removing controller module from chain" );
client()->lock();
m->disconnect();
controls_pack->remove( m );
modules_pack->remove( m );
build_process_queue();
client()->unlock();
redraw();
}
and Chain.C:906, which has the segfault itself:
/**********/
/* Client */
/**********/
void
Chain::process ( nframes_t nframes )
{
for ( std::list<Module*>::const_iterator i = process_queue.begin();
i != process_queue.end(); ++i )
{
Module *m = *i;
m->process( nframes ); // <-- segfault here
}
}
Looks to me like something's not getting removed completely. Maybe a
multithreaded race condition that always loses on my machine? (yes, I
know the removal is inside a lock, but anything can have bugs in it,
including the lock structure or perhaps more likely its use)
------------------------------------------------------------------------
*From:* John Rigg
*Sent:* Saturday, January 02, 2021 3:16AM
*To:* Non
*Subject:* Re: [non] Segfault when deleting a control
On Fri, Jan 01, 2021 at 09:51:35AM -0600, Aaron Duerksen wrote:
1. Start non-mixer
2. Add a strip
3. Add a Mono Pan, or anything else, really
4. Bind a control from it
5. Remove that control
6. Segfault
This happens every time, as demonstrated in this 45-second video screenshot:
https://www.youtube.com/watch?v=9mmC_ODMmfo
I would review the core dump and include at least parts of it here, if I
knew where it was.?? Lubuntu 20.04
I would also create a ticket on GitHub, if I could figure out how. I can see
the existing issues and read them, but I can't figure out how to add one,
even after creating an account.?? The obvious eye-catching way seems to
dead-end.
The 'issues' link on the GitHub page was recently removed, so I guess
this list is the official way to report bugs.
If you haven't already read it, see the bug reporting page at
https://non.tuxfamily.org/wiki/BugReports (ignoring references
to GitHub).
A gdb backtrace will be helpful. You'll need to compile non with
debugging enabled, ie.:
./waf configure --enable-debug
John
