int
sys_swapcontext(struct thread *td, struct swapcontext_args *uap)
{
ucontext_t uc;
int ret;
if (uap->oucp == NULL || uap->ucp == NULL)
ret = EINVAL;
else {
bzero(&uc, sizeof(ucontext_t));
get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
PROC_LOCK(td->td_proc);
uc.uc_sigmask = td->td_sigmask;
PROC_UNLOCK(td->td_proc);
ret = copyout(&uc, uap->oucp, UC_COPY_SIZE);
if (ret == 0) {
ret = copyin(uap->ucp, &uc, UC_COPY_SIZE);
if (ret == 0) {
ret = set_mcontext(td, &uc.uc_mcontext);
if (ret == 0) {
kern_sigprocmask(td, SIG_SETMASK,
&uc.uc_sigmask, NULL, 0);
}
}
}
}
return (ret == 0 ? EJUSTRETURN : ret);
}
struct getcontext_args {
struct __ucontext *ucp;
}
struct setcontext_args {
const struct __ucontext_t *ucp;
}
struct swapcontext_args {
struct __ucontext *oucp;
const struct __ucontext_t *ucp;
}
#endif
int
sys_getcontext(struct thread *td, struct getcontext_args *uap)
{
ucontext_t uc;
int ret;
if (uap->ucp == NULL)
ret = EINVAL;
else {
bzero(&uc, sizeof(ucontext_t));
get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
PROC_LOCK(td->td_proc);
uc.uc_sigmask = td->td_sigmask;
PROC_UNLOCK(td->td_proc);
ret = copyout(&uc, uap->ucp, UC_COPY_SIZE);
}
return (ret);
}
static int
get_mcontext32(struct thread *td, mcontext32_t *mcp, int flags)
{
mcontext_t mcp64;
unsigned i;
int error;
error = get_mcontext(td, &mcp64, flags);
if (error != 0)
return (error);
mcp->mc_onstack = mcp64.mc_onstack;
mcp->mc_pc = mcp64.mc_pc;
for (i = 0; i < 32; i++)
mcp->mc_regs[i] = mcp64.mc_regs[i];
mcp->sr = mcp64.sr;
mcp->mullo = mcp64.mullo;
mcp->mulhi = mcp64.mulhi;
mcp->mc_fpused = mcp64.mc_fpused;
for (i = 0; i < 33; i++)
mcp->mc_fpregs[i] = mcp64.mc_fpregs[i];
mcp->mc_fpc_eir = mcp64.mc_fpc_eir;
mcp->mc_tls = (int32_t)(intptr_t)mcp64.mc_tls;
return (0);
}
int
swapcontext(struct thread *td, struct swapcontext_args *uap)
{
ucontext_t uc;
int ret;
if (uap->oucp == NULL || uap->ucp == NULL)
ret = EINVAL;
else {
get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET);
PROC_LOCK(td->td_proc);
uc.uc_sigmask = td->td_sigmask;
PROC_UNLOCK(td->td_proc);
ret = copyout(&uc, uap->oucp, UC_COPY_SIZE);
if (ret == 0) {
ret = copyin(uap->ucp, &uc, UC_COPY_SIZE);
if (ret == 0) {
ret = set_mcontext(td, &uc.uc_mcontext);
if (ret == 0) {
SIG_CANTMASK(uc.uc_sigmask);
PROC_LOCK(td->td_proc);
td->td_sigmask = uc.uc_sigmask;
PROC_UNLOCK(td->td_proc);
}
}
}
}
return (ret == 0 ? EJUSTRETURN : ret);
}
/* Initializes a dcontext with the supplied state and calls dispatch */
void
dynamo_start(priv_mcontext_t *mc)
{
priv_mcontext_t *mcontext;
dcontext_t *dcontext = get_thread_private_dcontext();
ASSERT(dcontext != NULL);
thread_starting(dcontext);
/* Signal other threads for take over. */
dynamorio_take_over_threads(dcontext);
/* Set return address */
mc->pc = canonicalize_pc_target(dcontext, mc->pc);
dcontext->next_tag = mc->pc;
ASSERT(dcontext->next_tag != NULL);
/* transfer exec state to mcontext */
mcontext = get_mcontext(dcontext);
*mcontext = *mc;
/* clear pc */
mcontext->pc = 0;
DOLOG(2, LOG_TOP, {
byte *cur_esp;
GET_STACK_PTR(cur_esp);
LOG(THREAD, LOG_TOP, 2, "%s: next_tag="PFX", cur xsp="PFX", mc->xsp="PFX"\n",
__FUNCTION__, dcontext->next_tag, cur_esp, mc->xsp);
});
/*
* Save the calling context in (oucp) then switch to (ucp).
*
* Block all signals while switching contexts. get_mcontext() returns zero
* when retrieving a context.
*
* When some other thread calls set_mcontext() to resume our thread,
* the resume point causes get_mcontext() to return non-zero to us.
* Signals will be blocked and we must restore the signal mask before
* returning.
*/
int
_swapcontext(ucontext_t *oucp, const ucontext_t *ucp)
{
int ret;
ret = _sigprocmask(SIG_BLOCK, &sigset_block_all, &oucp->uc_sigmask);
if (ret == 0) {
if (get_mcontext(&oucp->uc_mcontext) == 0) {
ret = set_mcontext(&ucp->uc_mcontext);
} else {
ret = _sigprocmask(SIG_SETMASK, &oucp->uc_sigmask, NULL);
}
}
return(ret);
}
/* Initializes a dcontext with the supplied state and calls dispatch */
void
dynamo_start(priv_mcontext_t *mc)
{
priv_mcontext_t *mcontext;
dcontext_t *dcontext = get_thread_private_dcontext();
ASSERT(dcontext != NULL);
thread_starting(dcontext);
/* Signal other threads for take over. */
dynamorio_take_over_threads(dcontext);
/* Set return address */
dcontext->next_tag = mc->pc;
ASSERT(dcontext->next_tag != NULL);
/* transfer exec state to mcontext */
mcontext = get_mcontext(dcontext);
*mcontext = *mc;
/* clear pc */
mcontext->pc = 0;
/* Swap stacks so dispatch is invoked outside the application.
* We begin interpretation at the application return point,
* and thus we need to look like DR returned -- adjust the app
* stack to account for the return address.
*/
mcontext->xsp += XSP_SZ;
call_switch_stack(dcontext, dcontext->dstack, dispatch,
false/*not on initstack*/, true/*return on error*/);
/* In release builds, this will simply return and continue native
* execution. That's better than calling unexpected_return() which
* goes into an infinite loop.
*/
ASSERT_NOT_REACHED();
}
void
sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
{
struct thread *td;
struct proc *p;
struct trapframe *tf;
struct sigframe *fp, frame;
struct sigacts *psp;
int code, onstack, sig;
td = curthread;
p = td->td_proc;
PROC_LOCK_ASSERT(p, MA_OWNED);
sig = ksi->ksi_signo;
code = ksi->ksi_code;
psp = p->p_sigacts;
mtx_assert(&psp->ps_mtx, MA_OWNED);
tf = td->td_frame;
onstack = sigonstack(tf->tf_sp);
CTR4(KTR_SIG, "sendsig: td=%p (%s) catcher=%p sig=%d", td, p->p_comm,
catcher, sig);
/* Allocate and validate space for the signal handler context. */
if ((td->td_pflags & TDP_ALTSTACK) != 0 && !onstack &&
SIGISMEMBER(psp->ps_sigonstack, sig)) {
fp = (struct sigframe *)(td->td_sigstk.ss_sp +
td->td_sigstk.ss_size);
#if defined(COMPAT_43)
td->td_sigstk.ss_flags |= SS_ONSTACK;
#endif
} else {
fp = (struct sigframe *)td->td_frame->tf_sp;
}
/* Make room, keeping the stack aligned */
fp--;
fp = (struct sigframe *)STACKALIGN(fp);
/* Fill in the frame to copy out */
get_mcontext(td, &frame.sf_uc.uc_mcontext, 0);
get_fpcontext(td, &frame.sf_uc.uc_mcontext);
frame.sf_si = ksi->ksi_info;
frame.sf_uc.uc_sigmask = *mask;
frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) ?
((onstack) ? SS_ONSTACK : 0) : SS_DISABLE;
frame.sf_uc.uc_stack = td->td_sigstk;
mtx_unlock(&psp->ps_mtx);
PROC_UNLOCK(td->td_proc);
/* Copy the sigframe out to the user's stack. */
if (copyout(&frame, fp, sizeof(*fp)) != 0) {
/* Process has trashed its stack. Kill it. */
CTR2(KTR_SIG, "sendsig: sigexit td=%p fp=%p", td, fp);
PROC_LOCK(p);
sigexit(td, SIGILL);
}
tf->tf_x[0]= sig;
tf->tf_x[1] = (register_t)&fp->sf_si;
tf->tf_x[2] = (register_t)&fp->sf_uc;
tf->tf_elr = (register_t)catcher;
tf->tf_sp = (register_t)fp;
tf->tf_lr = (register_t)(PS_STRINGS - *(p->p_sysent->sv_szsigcode));
CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_elr,
tf->tf_sp);
PROC_LOCK(p);
mtx_lock(&psp->ps_mtx);
}