atexit and __cxa_atexit handlers that are either installed by unloaded
dso, or points to the functions provided by the dso.
Use _rtld_addr_phdr to locate segment information from the address of
private variable belonging to the dso, supplied by crtstuff.c. Provide
utility function __elf_phdr_match_addr to do the match of address against
dso executable segment.
Call back into libthr from __cxa_finalize using weak
__pthread_cxa_finalize symbol to remove any atfork handler which
function points into unloaded object.
The rtld needs private __pthread_cxa_finalize symbol to not require
resolution of the weak undefined symbol at initialization time. This
cannot work, since rtld is relocated before sym_zero is set up.
Idea by: kan
Reviewed by: kan (previous version)
MFC after: 3 weeks
finished using it. This allows the mutex's allocated memory to be
freed.
This is one sense a rather silly change, since at this point we're
less than a microsecond away from calling _exit; but fixing this
memory leak is likely to make life easier for anyone trying to
track down other memory leaks.
C++ ABI document at http://www.codesourcery.com/cxx-abi/abi.html#dso-dtor
The ABI was initially defined for ia64, but GCC3 and Intel compilers
have adopted it on other platforms.
This is the patch from PR bin/59552 with a number of changes by
me.
PR: bin/59552
Submitted by: Bradley T Hughes (bhughes at trolltech dot com)
be serialized. A mutex is used to protect the critical regions.
sbrk() and brk() are not thread safe. Replace use of sbrk() with
a call to malloc to avoid race when one thread calls atexit
while another thread calls malloc.
Reviewed by: deischen
