On Fri, Jan 27, 2023 at 05:02:33PM +0100, Christian Weisgerber wrote: > lang/sbcl will not work with x-only. > > I took another look at the warnings about data directives in .text. > In runtime/x86-64-assem.S we have snippets like these: > > GNAME(fun_end_breakpoint_trap): > TRAP > .byte trap_FunEndBreakpoint > hlt # We should never return here. > > GNAME(do_pending_interrupt): > TRAP > .byte trap_PendingInterrupt > ret > > GNAME(memory_fault_emulation_trap): > TRAP > .byte trap_MemoryFaultEmulation > > Where TRAP is defined to int3, and trap_* are consecutively numbered > constants. The other half of this is sigtrap_handler() in > runtime/x86-64-arch.c, which reads the byte after the int3 instruction > > trap = *(unsigned char *)OS_CONTEXT_PC(context); > > and then dispatches accordingly. > > ... And this brief analysis marks the end of my own involvement > with this port.
Unfortunately I don't have a new enough CPU to test xonly, so someone should probably mark it USE_NOEXECONLY
