/proc/<id>/maps can be read once per stack trace extraction

[bgedik]

Since I am not too familiar with the overall organization, it was not obvious to me how to achieve this, but ideally, we should not do this repeatedly.

[melintea]

Good point. It can be done via a hash map that would cache binaryname => base value

The map is accessed safely in bfd_vma compute_maps_base(const char * binfile) which is called via resolve(). resolve() operates under _lib_mutex which protects for multi-thread access.

If the process dynamically loads dynamic modules (as opposed to simply inking with) we will have to open /proc each time we do not find a binary in the map.

[bgedik]

One concern: If the same library is dynamically loaded/unloaded multiple times, it is not guaranteed to be mapped to the same location. Could it be safer to do this once at the beginning of stack trace extraction?