void
cheri_exec_setregs(struct thread *td)
{
struct cheri_frame *cfp;
struct cheri_signal *csigp;
/*
* XXXRW: Experimental CHERI ABI initialises $c0 with full user
* privilege, and all other user-accessible capability registers with
* no rights at all. The runtime linker/compiler/application can
* propagate around rights as required.
*/
cfp = &td->td_pcb->pcb_cheriframe;
bzero(cfp, sizeof(*cfp));
cheri_capability_set_user_c0(&cfp->cf_c0);
cheri_capability_set_user_stack(&cfp->cf_c11);
cheri_capability_set_user_idc(&cfp->cf_idc);
cheri_capability_set_user_pcc(&cfp->cf_pcc);
/*
* Also initialise signal-handling state; this can't yet be modified
* by userspace, but the principle is that signal handlers should run
* with ambient authority unless given up by the userspace runtime
* explicitly.
*/
csigp = &td->td_pcb->pcb_cherisignal;
bzero(csigp, sizeof(*csigp));
cheri_capability_set_user_c0(&csigp->csig_c0);
cheri_capability_set_user_stack(&csigp->csig_c11);
cheri_capability_set_user_idc(&csigp->csig_idc);
cheri_capability_set_user_pcc(&csigp->csig_pcc);
cheri_capability_set_user_sigcode(&csigp->csig_sigcode,
td->td_proc->p_sysent);
}
void
cheri_exec_setregs(struct thread *td, unsigned long entry_addr)
{
struct trapframe *frame;
struct cheri_signal *csigp;
/*
* We assume that the caller has initialised the trapframe to zeroes
* -- but do a quick assertion or two to catch programmer error. We
* might want to check this with a more thorough set of assertions in
* the future.
*/
frame = &td->td_pcb->pcb_regs;
KASSERT(*(uint64_t *)&frame->ddc == 0, ("%s: non-zero initial $ddc",
__func__));
KASSERT(*(uint64_t *)&frame->pcc == 0, ("%s: non-zero initial $epcc",
__func__));
/*
* XXXRW: Experimental CHERI ABI initialises $ddc with full user
* privilege, and all other user-accessible capability registers with
* no rights at all. The runtime linker/compiler/application can
* propagate around rights as required.
*/
cheri_capability_set_user_ddc(&frame->ddc);
cheri_capability_set_user_stc(&frame->stc);
cheri_capability_set_user_idc(&frame->idc);
cheri_capability_set_user_pcc(&frame->pcc);
cheri_capability_set_user_entry(&frame->c12, entry_addr);
/*
* Also initialise signal-handling state; this can't yet be modified
* by userspace, but the principle is that signal handlers should run
* with ambient authority unless given up by the userspace runtime
* explicitly.
*/
csigp = &td->td_pcb->pcb_cherisignal;
bzero(csigp, sizeof(*csigp));
cheri_capability_set_user_ddc(&csigp->csig_ddc);
cheri_capability_set_user_stc(&csigp->csig_stc);
cheri_capability_set_user_stc(&csigp->csig_default_stack);
cheri_capability_set_user_idc(&csigp->csig_idc);
cheri_capability_set_user_pcc(&csigp->csig_pcc);
cheri_capability_set_user_sigcode(&csigp->csig_sigcode,
td->td_proc->p_sysent);
/*
* Set up root for the userspace object-type capability tree. This
* can be queried using sysarch(2).
*/
cheri_capability_set_user_type(&td->td_pcb->pcb_typecap);
}
