Linux

Debugging Linux applications

LDD

Linux LDD is just a wrapper for:

LD_TRACE_LOADED_OBJECTS=1 <cmd>

Core dumps

To check core dump handler:

cat /proc/sys/kernel/core_pattern
|/usr/sbin/coredump-handler %h_%t_%p.core

Valgrind

valgrind --trace-children=yes --leak-check=full --show-leak-kinds=all <binary>

Disable Nvidia drivers and enable Intel embedded HD graphics driver

sudo apt-get purge nvidia-*
sudo apt-get install --reinstall xserver-xorg-video-intel libgl1-mesa-glx libgl1-mesa-dri mesa-utils xserver-xorg-core
sudo dpkg-reconfigure xserver-xorg
sudo update-alternatives --remove gl_conf /usr/lib/nvidia-current/ld.so.conf
reboot

Switch default compiler

(cc --version;c++ --version;gcc --version;g++ --version) | grep Debian
 cc (Debian 6.1.1-11) 6.1.1 20160802
 c++ (Debian 6.1.1-11) 6.1.1 20160802
 gcc (Debian 6.1.1-11) 6.1.1 20160802
 g++ (Debian 6.1.1-11) 6.1.1 20160802

sudo apt-get install gcc-4.9 g++-4.9

gcc-4.9 --version
 gcc-4.9 (Debian 4.9.3-14) 4.9.3

g++-4.9 --version
 g++-4.9 (Debian 4.9.3-14) 4.9.3

gcc-5 --version
 gcc-5 (Debian 5.4.1-1) 5.4.1 20160803

g++-5 --version
 g++-5 (Debian 5.4.1-1) 5.4.1 20160803

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-5 10
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.9 20
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-5 10
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.9 20
sudo update-alternatives --install /usr/bin/cc cc /usr/bin/gcc 30
sudo update-alternatives --set cc /usr/bin/gcc
sudo update-alternatives --install /usr/bin/c++ c++ /usr/bin/g++ 30
sudo update-alternatives --set c++ /usr/bin/g++

(cc --version;c++ --version;gcc --version;g++ --version) | grep Debian
 cc (Debian 4.9.3-14) 4.9.3
 c++ (Debian 4.9.3-14) 4.9.3
 gcc (Debian 4.9.3-14) 4.9.3
 g++ (Debian 4.9.3-14) 4.9.3

To go back:

sudo update-alternatives --config gcc
sudo update-alternatives --config g++