A handler that returns the context unchanged runs again on the same fault,
a handler that fixes the page with mprotect and returns lets the store
complete, and a handler that removes itself and returns ends the process
with the fault (checked in a child process, so a loop fails on a timeout).
Co-Authored-By: Claude Opus 5.5 <[email protected]>
A handler installed for SIGILL, SIGFPE, SIGBUS or SIGSEGV now receives
the faults raised in title code instead of the process ending, with
mc_trapno, mc_addr and mc_err filled as FreeBSD 11's amd64 trap() does.
On Windows the crash reporter's vectored handler offers unclaimed faults
to libkernel, which redirects the thread to a stub that runs the handler
outside the exception dispatcher; on Linux chained host signal handlers
classify faults by REG_TRAPNO.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
