Segfault when used in combination with "noise-suppression-for-voice"

[fulhax]

Segfault when used in combination with "noise-suppression-for-voice"

[c0r73x]

Seems after one of the latest merges it segfaults always, I will check later this evening why this is.

[CodingCellist]

So I did a bit of debugging myself, and discovered that it seems to be something to do with src/pa.cpp:457, which is:

    p->app_name = pa_proplist_gets(info->proplist, PA_PROP_APPLICATION_NAME);

However, what is odd is that the segfault seems to occur (based on gdb output) because the basic_string.h file cannot be found. The program is looking for it in an absolute path starting with /build, but the file is actually located in /usr/include/c++. So the file's not missing, the program just seems to be looking for it in the wrong place... This is particularly confusing, as I have not custom-installed the C++ standard libraries. I've installed everything through pacman.

Any idea what the issue might be? Or how to investigate it further (I've not done ncurses or pa development before)?

GDB backtrace:

(gdb) backtrace
#0  0x00007ffff7af6a85 in __strlen_avx2 () from /usr/lib/libc.so.6
#1  0x00007ffff7dfe35a in std::char_traits<char>::length (__s=0x0) at /build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/char_traits.h:357
#2  std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::assign (__s=0x0, this=0x7fffec017470)
    at /build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h:1438
#3  std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::operator= (this=0x7fffec017470, __s=0x0)
    at /build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h:676
#4  0x0000000100023b28 in Pa::update_input (this=0x100041840 <pulse>, info=0x7ffff738c810) at $HOME/Projects/ncpamixer-git/src/pa.cpp:457
#5  0x00000001000242bc in Pa::ctx_inputlist_cb (ctx=0x100054be0, info=0x7ffff738c810, eol=0, instance=0x100041840 <pulse>) at $HOME/Projects/ncpamixer-git/src/pa.cpp:655
#6  0x00007ffff7eebd76 in ?? () from /usr/lib/libpulse.so.0
#7  0x00007ffff7943684 in ?? () from /usr/lib/pulseaudio/libpulsecommon-13.0.so
#8  0x00007ffff79439ff in pa_pdispatch_run () from /usr/lib/pulseaudio/libpulsecommon-13.0.so
#9  0x00007ffff7ef5f01 in ?? () from /usr/lib/libpulse.so.0
#10 0x00007ffff793a339 in ?? () from /usr/lib/pulseaudio/libpulsecommon-13.0.so
#11 0x00007ffff793be8b in ?? () from /usr/lib/pulseaudio/libpulsecommon-13.0.so
#12 0x00007ffff793c027 in ?? () from /usr/lib/pulseaudio/libpulsecommon-13.0.so
#13 0x00007ffff793943a in ?? () from /usr/lib/pulseaudio/libpulsecommon-13.0.so
#14 0x00007ffff7edfb93 in pa_mainloop_dispatch () from /usr/lib/libpulse.so.0
#15 0x00007ffff7ee3311 in pa_mainloop_iterate () from /usr/lib/libpulse.so.0
#16 0x00007ffff7ee33b1 in pa_mainloop_run () from /usr/lib/libpulse.so.0
#17 0x00007ffff7ed361e in ?? () from /usr/lib/libpulse.so.0
#18 0x00007ffff792dd1c in ?? () from /usr/lib/pulseaudio/libpulsecommon-13.0.so
#19 0x00007ffff7ea53e9 in start_thread () from /usr/lib/libpthread.so.0
#20 0x00007ffff7a94293 in clone () from /usr/lib/libc.so.6
(gdb)

GDB output concerning line 457:

Thread 2 " threaded-ml" hit Breakpoint 1, Pa::update_input (this=0x100041840 <pulse>, info=0x7ffff738c810) at $HOME/Projects/ncpamixer-git/src/pa.cpp:457
457         p->app_name = pa_proplist_gets(info->proplist, PA_PROP_APPLICATION_NAME);
(gdb) p *info
$1 = {index = 945, name=0x7ffff0016af0 "LADSPA Stream", owner_module = 25, client=4294967295, sink = 1, sample_spec = {format = PA_SAMPLE_FLOAT32LE, rate = 48000, channels = 2 '\002'}, channel_map = {
    channels = 2 '\002', map = {PA_CHANNEL_POSITION_FRONT_LEFT, PA_CHANNEL_POSITION_FRONT_RIGHT, PA_CHANNEL_POSITION_MONO <repeats 30 times>}}, volume = {channels = 2 '\002', values = {65536, 65536,
    0 <repeats 30 times>}}, buffer_usec = 0, sink_usec = 73815, resample_method = 07ffff0016b35 "copy", driver = 0x7ffff0016b3b "module-ladspa-sink.c", mute = 0, proplist = 0x7ffff0012230, corked = 0,
  has_volume = 1, volume_writable = 0, format = 0x7ffff0011080}
(gdb) p *(info->proplist)
$2 = <incomplete type>
(gdb) s
                                                            std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::operator= (this=0x7ffff0017470, __s=0x0)
    at /build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h:675
675     /build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h: No such file or directory.
(gdb) s
                                                            676         in /build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h
(gdb) s
std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::assign (__s=0x0, this=0x7ffff0017470) at /build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h:676
676     in /build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h
(gdb) s
std::char_traits<char>::length (__s=0x0) at /build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/char_traits.h:357
357     /build/gcc/src/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/char_traits.h: No such file or directory.
(gdb) s
                                                            Thread 2 "threaded-ml" received signal SIGSEGV, Segmentation fault.
                                                                                                                               0x00007ffff7af6a85 in __strlen_avx2 () from /usr/lib/libc.so.6
(gdb)

[c0r73x]

Looks to me that it has something to do with this commit abe0550, I would expect that pa_proplist_gets returns a char pointer but since it crashes when trying to convert it to a string I would guess that it for some reason returns a null pointer.

[c0r73x]

To fix it i would probably do something like

readd setter

void PaInput::setAppName(const char *name)
{
    if(name != nullptr) {
        app_name = name;
    }
}

and change back the prop getters to be used like this

p->setAppName(pa_proplist_gets(info->proplist, PA_PROP_APPLICATION_NAME));

I can't test it now since i'm at work, and I only have OSX here.