int
set_regs(struct lwp *lp, struct reg *regs)
{
struct trapframe *tp;
tp = lp->lwp_md.md_regs;
if (!EFL_SECURE(regs->r_eflags, tp->tf_eflags) ||
!CS_SECURE(regs->r_cs))
return (EINVAL);
tp->tf_gs = regs->r_gs;
tp->tf_fs = regs->r_fs;
tp->tf_es = regs->r_es;
tp->tf_ds = regs->r_ds;
tp->tf_edi = regs->r_edi;
tp->tf_esi = regs->r_esi;
tp->tf_ebp = regs->r_ebp;
tp->tf_ebx = regs->r_ebx;
tp->tf_edx = regs->r_edx;
tp->tf_ecx = regs->r_ecx;
tp->tf_eax = regs->r_eax;
tp->tf_eip = regs->r_eip;
tp->tf_cs = regs->r_cs;
tp->tf_eflags = regs->r_eflags;
tp->tf_esp = regs->r_esp;
tp->tf_ss = regs->r_ss;
return (0);
}
int
set_regs32(struct thread *td, struct reg32 *regs)
{
struct pcb *pcb;
struct trapframe *tp;
tp = td->td_frame;
if (!EFL_SECURE(regs->r_eflags, tp->tf_rflags) || !CS_SECURE(regs->r_cs))
return (EINVAL);
pcb = td->td_pcb;
tp->tf_gs = regs->r_gs;
tp->tf_fs = regs->r_fs;
tp->tf_es = regs->r_es;
tp->tf_ds = regs->r_ds;
set_pcb_flags(pcb, PCB_FULL_IRET);
tp->tf_flags = TF_HASSEGS;
tp->tf_rdi = regs->r_edi;
tp->tf_rsi = regs->r_esi;
tp->tf_rbp = regs->r_ebp;
tp->tf_rbx = regs->r_ebx;
tp->tf_rdx = regs->r_edx;
tp->tf_rcx = regs->r_ecx;
tp->tf_rax = regs->r_eax;
tp->tf_rip = regs->r_eip;
tp->tf_cs = regs->r_cs;
tp->tf_rflags = regs->r_eflags;
tp->tf_rsp = regs->r_esp;
tp->tf_ss = regs->r_ss;
return (0);
}
int
ofreebsd32_sigreturn(struct thread *td, struct ofreebsd32_sigreturn_args *uap)
{
struct ia32_sigcontext3 sc, *scp;
struct trapframe *regs;
int eflags, error;
ksiginfo_t ksi;
regs = td->td_frame;
error = copyin(uap->sigcntxp, &sc, sizeof(sc));
if (error != 0)
return (error);
scp = ≻
eflags = scp->sc_eflags;
if (!EFL_SECURE(eflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) {
return (EINVAL);
}
if (!CS_SECURE(scp->sc_cs)) {
ksiginfo_init_trap(&ksi);
ksi.ksi_signo = SIGBUS;
ksi.ksi_code = BUS_OBJERR;
ksi.ksi_trapno = T_PROTFLT;
ksi.ksi_addr = (void *)regs->tf_rip;
trapsignal(td, &ksi);
return (EINVAL);
}
regs->tf_ds = scp->sc_ds;
regs->tf_es = scp->sc_es;
regs->tf_fs = scp->sc_fs;
regs->tf_gs = scp->sc_gs;
regs->tf_rax = scp->sc_eax;
regs->tf_rbx = scp->sc_ebx;
regs->tf_rcx = scp->sc_ecx;
regs->tf_rdx = scp->sc_edx;
regs->tf_rsi = scp->sc_esi;
regs->tf_rdi = scp->sc_edi;
regs->tf_cs = scp->sc_cs;
regs->tf_ss = scp->sc_ss;
regs->tf_rbp = scp->sc_ebp;
regs->tf_rsp = scp->sc_esp;
regs->tf_rip = scp->sc_eip;
regs->tf_rflags = eflags;
if (scp->sc_onstack & 1)
td->td_sigstk.ss_flags |= SS_ONSTACK;
else
td->td_sigstk.ss_flags &= ~SS_ONSTACK;
kern_sigprocmask(td, SIG_SETMASK, (sigset_t *)&scp->sc_mask, NULL,
SIGPROCMASK_OLD);
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
return (EJUSTRETURN);
}
int
sys_sigreturn(struct sigreturn_args *uap)
{
struct lwp *lp = curthread->td_lwp;
struct trapframe *regs;
ucontext_t ucp;
int cs;
int eflags;
int error;
error = copyin(uap->sigcntxp, &ucp, sizeof(ucp));
if (error)
return (error);
regs = lp->lwp_md.md_regs;
eflags = ucp.uc_mcontext.mc_eflags;
#if 0
if (eflags & PSL_VM) {
struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs;
struct vm86_kernel *vm86;
/*
* if pcb_ext == 0 or vm86_inited == 0, the user hasn't
* set up the vm86 area, and we can't enter vm86 mode.
*/
if (lp->lwp_thread->td_pcb->pcb_ext == 0)
return (EINVAL);
vm86 = &lp->lwp_thread->td_pcb->pcb_ext->ext_vm86;
if (vm86->vm86_inited == 0)
return (EINVAL);
/* go back to user mode if both flags are set */
if ((eflags & PSL_VIP) && (eflags & PSL_VIF))
trapsignal(lp->lwp_proc, SIGBUS, 0);
if (vm86->vm86_has_vme) {
eflags = (tf->tf_eflags & ~VME_USERCHANGE) |
(eflags & VME_USERCHANGE) | PSL_VM;
} else {
vm86->vm86_eflags = eflags; /* save VIF, VIP */
eflags = (tf->tf_eflags & ~VM_USERCHANGE) | (eflags & VM_USERCHANGE) | PSL_VM;
}
bcopy(&ucp.uc_mcontext.mc_gs, tf, sizeof(struct trapframe));
tf->tf_eflags = eflags;
tf->tf_vm86_ds = tf->tf_ds;
tf->tf_vm86_es = tf->tf_es;
tf->tf_vm86_fs = tf->tf_fs;
tf->tf_vm86_gs = tf->tf_gs;
tf->tf_ds = _udatasel;
tf->tf_es = _udatasel;
#if 0
tf->tf_fs = _udatasel;
tf->tf_gs = _udatasel;
#endif
} else
#endif
{
/*
* Don't allow users to change privileged or reserved flags.
*/
/*
* XXX do allow users to change the privileged flag PSL_RF.
* The cpu sets PSL_RF in tf_eflags for faults. Debuggers
* should sometimes set it there too. tf_eflags is kept in
* the signal context during signal handling and there is no
* other place to remember it, so the PSL_RF bit may be
* corrupted by the signal handler without us knowing.
* Corruption of the PSL_RF bit at worst causes one more or
* one less debugger trap, so allowing it is fairly harmless.
*/
if (!EFL_SECURE(eflags & ~PSL_RF, regs->tf_eflags & ~PSL_RF)) {
kprintf("sigreturn: eflags = 0x%x\n", eflags);
return(EINVAL);
}
/*
* Don't allow users to load a valid privileged %cs. Let the
* hardware check for invalid selectors, excess privilege in
* other selectors, invalid %eip's and invalid %esp's.
*/
cs = ucp.uc_mcontext.mc_cs;
if (!CS_SECURE(cs)) {
kprintf("sigreturn: cs = 0x%x\n", cs);
trapsignal(lp, SIGBUS, T_PROTFLT);
return(EINVAL);
}
bcopy(&ucp.uc_mcontext.mc_gs, regs, sizeof(struct trapframe));
}
/*
* Restore the FPU state from the frame
*/
crit_enter();
npxpop(&ucp.uc_mcontext);
if (ucp.uc_mcontext.mc_onstack & 1)
lp->lwp_sigstk.ss_flags |= SS_ONSTACK;
else
lp->lwp_sigstk.ss_flags &= ~SS_ONSTACK;
lp->lwp_sigmask = ucp.uc_sigmask;
SIG_CANTMASK(lp->lwp_sigmask);
crit_exit();
return(EJUSTRETURN);
}
