unw_flush_cache man page
unw_flush_cache -- flush cached info
void unw_flush_cache(unw_addr_space_t as, unw_word_t lo, unw_word_t hi);
The unw_flush_cache() routine flushes all cached info as it relates to address-range lo to hi (non-inclusive) in the target address-space as. In addition, all info cached for address-space as that is not tied to a particular code-range is also flushed. For example, the address of the dynamic registration list is not tied to a code-range and its cached value (if any) is flushed by a call to this routine. The address range specified by lo and hi should be understood as a hint: unw_flush_cache() may flush more information than requested, but never less. In other words, unw_flush_cache() may overflush, but not underflush.
As a special case, if arguments lo and hi are both 0, all information cached on behalf of address space as is flushed.
The unw_flush_cache() routine cannot fail and does not return a value.
Thread and Signal Safety
The unw_flush_cache() routine is thread-safe as well as safe to use from a signal handler.