Currently we use dlsym on pthread_cond_wait$UNIX2003 to find a
function that indicates that new_sem_from_pool is on the stack. This
works on 10.5, but on 10.6 I could not find a single reliable
indicator that would work with dlsym.
The good news is that dladdr works with any symbol, not just exported
ones. To find the address of new_sem_from_pool, we set up a malloc logger
and force a call to new_sem_from_pool. From the logger callback we walk
the stack trying dladdr on every address.
To force a call to new_sem_from_pool, the initialization code has to be the
first to use semaphores, so it is now run from NS_LogInit.
This works on 10.6 and 10.5 (but we have to look for
"pthread_cond_wait$UNIX2003"). In 10.7 the call to malloc is gone, so we don't
have to worry about critical addresses on it anymore.
Currently we use dlsym on pthread_cond_wait$UNIX2003 to find a
function that indicates that new_sem_from_pool is on the stack. This
works on 10.5, but on 10.6 I could not find a single reliable
indicator that would work with dlsym.
The good news is that dladdr works with any symbol, not just exported
ones. To find the address of new_sem_from_pool, we set up a malloc logger
and force a call to new_sem_from_pool. From the logger callback we walk
the stack trying dladdr on every address.
To for a call to new_sem_from_pool, the initialization code has to be the
first to use semaphores, so it is now run from NS_LogInit.
This works on 10.6 and 10.5 (but we have to look for
"pthread_cond_wait$UNIX2003"). In 10.7 the call to malloc is gone, so we don't
have to worry about critical addresses on it anymore.
