I am looking at the /proc/self/maps file. i find that for every shared library there are 4 sections with different permission. what are the reasons for this ? does that mean the same library is loaded 4 times ? e.g. 7fb543e5d000-7fb54401a000 r-xp 00000000 08:01 6033115 /lib/x86_64-linux-gnu/libc-2.17.so 7fb54401a000-7fb54421a000 ---p 001bd000 08:01 6033115 /lib/x86_64-linux-gnu/libc-2.17.so 7fb54421a000-7fb54421e000 r--p 001bd000 08:01 6033115 /lib/x86_64-linux-gnu/libc-2.17.so 7fb54421e000-7fb544220000 rw-p 001c1000 08:01 6033115 /lib/x86_64-linux-gnu/libc-2.17.so 7fb544220000-7fb544225000 rw-p 00000000 00:00 0 7fb544225000-7fb54423a000 r-xp 00000000 08:01 6029447 /lib/x86_64-linux-gnu/libgcc_s.so.1 7fb54423a000-7fb544439000 ---p 00015000 08:01 6029447 /lib/x86_64-linux-gnu/libgcc_s.so.1 7fb544439000-7fb54443a000 r--p 00014000 08:01 6029447 /lib/x86_64-linux-gnu/libgcc_s.so.1 7fb54443a000-7fb54443b000 rw-p 00015000 08:01 6029447 /lib/x86_64-linux-gnu/libgcc_s.so.1 7fb54443b000-7fb54453e000 r-xp 00000000 08:01 6032973 /lib/x86_64-linux-gnu/libm-2.17.so 7fb54453e000-7fb54473d000 ---p 00103000 08:01 6032973 /lib/x86_64-linux-gnu/libm-2.17.so 7fb54473d000-7fb54473e000 r--p 00102000 08:01 6032973 /lib/x86_64-linux-gnu/libm-2.17.so 7fb54473e000-7fb54473f000 rw-p 00103000 08:01 6032973 /lib/x86_64-linux-gnu/libm-2.17.so Gary