/*
* Handle signals, upcalls, profiling, and other AST's and/or tasks that
* must be completed before we can return to or try to return to userland.
*
* Note that td_sticks is a 64 bit quantity, but there's no point doing 64
* arithmatic on the delta calculation so the absolute tick values are
* truncated to an integer.
*/
static void
userret(struct lwp *lp, struct trapframe *frame, int sticks)
{
struct proc *p = lp->lwp_proc;
int sig;
int ptok;
/*
* Charge system time if profiling. Note: times are in microseconds.
* This may do a copyout and block, so do it first even though it
* means some system time will be charged as user time.
*/
if (p->p_flags & P_PROFIL) {
addupc_task(p, frame->tf_rip,
(u_int)((int)lp->lwp_thread->td_sticks - sticks));
}
recheck:
/*
* Specific on-return-to-usermode checks (LWP_MP_WEXIT,
* LWP_MP_VNLRU, etc).
*/
if (lp->lwp_mpflags & LWP_MP_URETMASK)
lwpuserret(lp);
/*
* Block here if we are in a stopped state.
*/
if (STOPLWP(p, lp)) {
lwkt_gettoken(&p->p_token);
tstop();
lwkt_reltoken(&p->p_token);
goto recheck;
}
while (dump_stop_usertds) {
tsleep(&dump_stop_usertds, 0, "dumpstp", 0);
}
/*
* Post any pending upcalls. If running a virtual kernel be sure
* to restore the virtual kernel's vmspace before posting the upcall.
*/
if (p->p_flags & (P_SIGVTALRM | P_SIGPROF)) {
lwkt_gettoken(&p->p_token);
if (p->p_flags & P_SIGVTALRM) {
p->p_flags &= ~P_SIGVTALRM;
ksignal(p, SIGVTALRM);
}
if (p->p_flags & P_SIGPROF) {
p->p_flags &= ~P_SIGPROF;
ksignal(p, SIGPROF);
}
lwkt_reltoken(&p->p_token);
goto recheck;
}
/*
* Post any pending signals. If running a virtual kernel be sure
* to restore the virtual kernel's vmspace before posting the signal.
*
* WARNING! postsig() can exit and not return.
*/
if ((sig = CURSIG_LCK_TRACE(lp, &ptok)) != 0) {
postsig(sig, ptok);
goto recheck;
}
/*
* block here if we are swapped out, but still process signals
* (such as SIGKILL). proc0 (the swapin scheduler) is already
* aware of our situation, we do not have to wake it up.
*/
if (p->p_flags & P_SWAPPEDOUT) {
lwkt_gettoken(&p->p_token);
p->p_flags |= P_SWAPWAIT;
swapin_request();
if (p->p_flags & P_SWAPWAIT)
tsleep(p, PCATCH, "SWOUT", 0);
p->p_flags &= ~P_SWAPWAIT;
lwkt_reltoken(&p->p_token);
goto recheck;
}
/*
* In a multi-threaded program it is possible for a thread to change
* signal state during a system call which temporarily changes the
* signal mask. In this case postsig() might not be run and we
* have to restore the mask ourselves.
*/
if (lp->lwp_flags & LWP_OLDMASK) {
lp->lwp_flags &= ~LWP_OLDMASK;
lp->lwp_sigmask = lp->lwp_oldsigmask;
goto recheck;
}
}
/*
* Handle signals, upcalls, profiling, and other AST's and/or tasks that
* must be completed before we can return to or try to return to userland.
*
* Note that td_sticks is a 64 bit quantity, but there's no point doing 64
* arithmatic on the delta calculation so the absolute tick values are
* truncated to an integer.
*/
static void
userret(struct lwp *lp, struct trapframe *frame, int sticks)
{
struct proc *p = lp->lwp_proc;
void (*hook)(void);
int sig;
if (p->p_userret != NULL) {
hook = p->p_userret;
p->p_userret = NULL;
(*hook)();
}
/*
* Charge system time if profiling. Note: times are in microseconds.
* This may do a copyout and block, so do it first even though it
* means some system time will be charged as user time.
*/
if (p->p_flags & P_PROFIL) {
addupc_task(p, frame->tf_eip,
(u_int)((int)lp->lwp_thread->td_sticks - sticks));
}
recheck:
/*
* If the jungle wants us dead, so be it.
*/
if (lp->lwp_mpflags & LWP_MP_WEXIT) {
lwkt_gettoken(&p->p_token);
lwp_exit(0);
lwkt_reltoken(&p->p_token); /* NOT REACHED */
}
/*
* Block here if we are in a stopped state.
*/
if (p->p_stat == SSTOP || dump_stop_usertds) {
lwkt_gettoken(&p->p_token);
tstop();
lwkt_reltoken(&p->p_token);
goto recheck;
}
/*
* Post any pending upcalls. If running a virtual kernel be sure
* to restore the virtual kernel's vmspace before posting the upcall.
*/
if (p->p_flags & (P_SIGVTALRM | P_SIGPROF | P_UPCALLPEND)) {
lwkt_gettoken(&p->p_token);
if (p->p_flags & P_SIGVTALRM) {
p->p_flags &= ~P_SIGVTALRM;
ksignal(p, SIGVTALRM);
}
if (p->p_flags & P_SIGPROF) {
p->p_flags &= ~P_SIGPROF;
ksignal(p, SIGPROF);
}
if (p->p_flags & P_UPCALLPEND) {
p->p_flags &= ~P_UPCALLPEND;
postupcall(lp);
}
lwkt_reltoken(&p->p_token);
goto recheck;
}
/*
* Post any pending signals. If running a virtual kernel be sure
* to restore the virtual kernel's vmspace before posting the signal.
*
* WARNING! postsig() can exit and not return.
*/
if ((sig = CURSIG_TRACE(lp)) != 0) {
lwkt_gettoken(&p->p_token);
postsig(sig);
lwkt_reltoken(&p->p_token);
goto recheck;
}
/*
* block here if we are swapped out, but still process signals
* (such as SIGKILL). proc0 (the swapin scheduler) is already
* aware of our situation, we do not have to wake it up.
*/
if (p->p_flags & P_SWAPPEDOUT) {
lwkt_gettoken(&p->p_token);
get_mplock();
p->p_flags |= P_SWAPWAIT;
swapin_request();
if (p->p_flags & P_SWAPWAIT)
tsleep(p, PCATCH, "SWOUT", 0);
p->p_flags &= ~P_SWAPWAIT;
rel_mplock();
lwkt_reltoken(&p->p_token);
goto recheck;
}
/*
* In a multi-threaded program it is possible for a thread to change
* signal state during a system call which temporarily changes the
* signal mask. In this case postsig() might not be run and we
* have to restore the mask ourselves.
*/
if (lp->lwp_flags & LWP_OLDMASK) {
lp->lwp_flags &= ~LWP_OLDMASK;
lp->lwp_sigmask = lp->lwp_oldsigmask;
goto recheck;
}
}
