Why do we mmap data that is already mmapped?

[workingjubilee]

The basic strategy for backtrace symbolication on Linux:

• We use a combination of dl_iterate_phdr and opening /proc/self/maps to learn about what memory objects are loaded
• We obtain a bunch of filenames for these memory objects, their dynamic libraries
• We then later mmap these filenames into memory.
• ...WAIT A TICK?!?

...why do we map things into memory that we almost certainly know are already in-memory objects?