[Pkg-bluetooth-maintainers] Bug#856487: libsbc1: compiling with gcc > 4.9 causes stack corruption

[Dr. Johann Pfefferl]

Package: libsbc1
Version: 1.3-1+b2
Followup-For: Bug #856487

Dear Maintainer,

if I connect my bluetooth headphone to the machine and switch audio to
the bluetooth device pulseaudio crashes. The function shown by gdb is
"sbc_analyze_eight_armv6" from the libsbc library.

Now if I replace the original debian library by the following:

git clone git://git.debian.org/pkg-bluetooth/sbc.git
cd sbc
CC=gcc-4.9 ./configure
make
DESTDIR=$PWD/installdir
make install DESTDIR=$DESTDIR
install -v $DESTDIR/usr/local/lib/libsbc.so.1.2.1 /usr/lib/arm-linux-gnueabihf/libsbc.so.1.2.1

and restart pulseaudio by

pactl exit;pactl info

and afterwards switch on my bluetooth headset and connect to the headset
by pavucontrol then everything works as expected.

If I do the same with CC=gcc-6 pulseaudio crashes.

The function sbc_analyze_eight_armv6 is an assembler function without
any comment :(. It seems that the calling convention of this direct
assembler routine has changed from gcc verion 4 to 6.

-- System Information:
Debian Release: 9.0
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: armhf (armv7l)

Kernel: Linux 4.10.1-00038-g3d0309a
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages libsbc1 depends on:
ii  libc6  2.24-9

libsbc1 recommends no packages.

libsbc1 suggests no packages.

-- no debconf information