genode/repos/base/lib/symbols
Norman Feske 852ab79359 Move atexit handling from base lib to libc
This patch untangles the interplay of the base library and the libc
during the exit handling.

- The CXA ABI for the atexit handling is now provided by the libc.
  For plain Genode components without libc dependency, __cxa_atexit
  is a no-op, which is consistent with Genode's notion of components.

- The 'abort' implementation of the base library no longer calls
  'genode_exit' but merely 'sleep_forever'. This way, the cxx library
  no longer depends on a 'genode_exit' implementation.

- The libc provides 'atexit' support by storing metadata on the
  libc kernel's heap now, thereby eliminating the former bounded
  maximum number of atexit handlers.

- Shared-library dtors are no longer called via the atexit mechanism
  by explicitly by the dynamic linker. This slightly changes the
  call order of destructors (adjustment of the ldso test). Functions
  marked as destructors are called after the atexit handlers now.

- The libc executes atexit handlers in the application context,
  which supports the I/O operations in those handles, in particular
  the closing of file descriptors.

Fixes #3851
2020-08-25 11:50:09 +02:00
..
ld Move atexit handling from base lib to libc 2020-08-25 11:50:09 +02:00