master
Make two corrections to the vfork(2) stub: * with IBT, it can't return via an indirect jump as that would require the *caller* to have an endbr64 * to support a potential vmspace-sharing implementation, keep the retguard value in an arg register across the underlying syscall
Add retguard to amd64 syscalls.
Retguard addition in commit 72pYktDvmJhq7OyF was based on the understanding that the removal of the off_t padding, amd64 syscalls no longer passed a 7th or later argument. We overlooked that syscall(2) bumps the arg count by one, so six argument calls like SYS_sysctl still pass an argument on the stack.
Populate the non-LOAD openbsd.syscalls section (and PT_OPENBSD_SYSCALL) with {uint offset, uint syscall#} entries in libc & ld.so. In libc a few syscall# entries (break, sigprocmask, _tfork, _threxit) are duplicated because additional or inline uses occur (that situation is handled elsewhere) ok kettenis