int
linux_sys_exit(struct lwp *l, const struct linux_sys_exit_args *uap, register_t *retval)
{
lwp_exit(l);
return 0;
}
int
sys__lwp_exit(struct lwp *l, const void *v, register_t *retval)
{
lwp_exit(l);
return 0;
}
/*
* Extended exit --
* Death of a lwp or process with optional bells and whistles.
*
* MPALMOSTSAFE
*/
int
sys_extexit(struct extexit_args *uap)
{
struct proc *p = curproc;
int action, who;
int error;
action = EXTEXIT_ACTION(uap->how);
who = EXTEXIT_WHO(uap->how);
/* Check parameters before we might perform some action */
switch (who) {
case EXTEXIT_PROC:
case EXTEXIT_LWP:
break;
default:
return (EINVAL);
}
switch (action) {
case EXTEXIT_SIMPLE:
break;
case EXTEXIT_SETINT:
error = copyout(&uap->status, uap->addr, sizeof(uap->status));
if (error)
return (error);
break;
default:
return (EINVAL);
}
lwkt_gettoken(&p->p_token);
switch (who) {
case EXTEXIT_LWP:
/*
* Be sure only to perform a simple lwp exit if there is at
* least one more lwp in the proc, which will call exit1()
* later, otherwise the proc will be an UNDEAD and not even a
* SZOMB!
*/
if (p->p_nthreads > 1) {
lwp_exit(0); /* called w/ p_token held */
/* NOT REACHED */
}
/* else last lwp in proc: do the real thing */
/* FALLTHROUGH */
default: /* to help gcc */
case EXTEXIT_PROC:
lwkt_reltoken(&p->p_token);
exit1(W_EXITCODE(uap->status, 0));
/* NOTREACHED */
}
/* NOTREACHED */
lwkt_reltoken(&p->p_token); /* safety */
}
/*
* Exit the calling lwp
*/
void
syslwp_exit()
{
proc_t *p = ttoproc(curthread);
mutex_enter(&p->p_lock);
lwp_exit();
/* NOTREACHED */
}
/*
* Destroy an inactive kthread. The kthread must be in the LSIDL state.
*/
void
kthread_destroy(lwp_t *l)
{
KASSERT((l->l_flag & LW_SYSTEM) != 0);
KASSERT(l->l_stat == LSIDL);
lwp_exit(l);
}
static void counter(long num)
{
if ( num ) {
lwp_create((lwpfun)counter,(void*)num-1,STACKSIZE);
printf("%ld\n",num);
} else {
printf("Bye\n");
}
lwp_exit();
}
static void indentnum(uintptr_t num) {
/* print the number num num times, indented by 5*num spaces
* * Not terribly interesting, but it is instructive.
* */
int id;
id = (int)num;
printf("Greetings from Thread %d. Yielding...\n",id);
lwp_yield();
printf("I (%d) am still alive. Goodbye.\n",id);
lwp_exit();
}
int main(int argc, char *argv[]){
if ( argc == -1 ) {
/* can't happen, but the linker doesn't know it. */
/* these are all the required external symbols */
lwp_create(NULL,NULL,0);
lwp_exit();
lwp_yield();
lwp_start();
lwp_stop();
lwp_set_scheduler(NULL);
}
printf("Linked successfully.\n");
exit(0);
}
static void indentnum(void *num) {
/* print the number num num times, indented by 5*num spaces
* Not terribly interesting, but it is instructive.
*/
int howfar,i;
howfar=(int)num; /* interpret num as an integer */
for(i=0;i<howfar;i++){
printf("%*d\n",howfar*5,howfar);
lwp_yield(); /* let another have a turn */
}
lwp_exit(); /* bail when done. This should
* be unnecessary if the stack has
* been properly prepared
*/
}
/*
* Release resources.
* Enter zombie state.
* Wake up parent and init processes,
* and dispose of children.
*/
void
exit(int why, int what)
{
/*
* If proc_exit() fails, then some other lwp in the process
* got there first. We just have to call lwp_exit() to allow
* the other lwp to finish exiting the process. Otherwise we're
* restarting init, and should return.
*/
if (proc_exit(why, what) != 0) {
mutex_enter(&curproc->p_lock);
ASSERT(curproc->p_flag & SEXITLWPS);
lwp_exit();
/* NOTREACHED */
}
}
static void indentnum(uintptr_t num) {
/* print the number num num times, indented by 5*num spaces
* Not terribly interesting, but it is instructive.
*/
int howfar,i;
howfar=(int)num; /* interpret num as an integer */
for(i=0;i<ITERS;i++){
printf("%*d\n",howfar*5,howfar);
if ( num == NUMTHREADS && i == ITERS - 3 ) {
checktids();
exit(EXIT_SUCCESS);
}
lwp_yield(); /* let another have a turn */
}
lwp_exit(); /* bail when done. This should
* be unnecessary if the stack has
* been properly prepared
*/
}
/*
* Cause a kernel thread to exit. Assumes the exiting thread is the
* current context.
*/
void
kthread_exit(int ecode)
{
const char *name;
lwp_t *l = curlwp;
/* We can't do much with the exit code, so just report it. */
if (ecode != 0) {
if ((name = l->l_name) == NULL)
name = "unnamed";
printf("WARNING: kthread `%s' (%d) exits with status %d\n",
name, l->l_lid, ecode);
}
/* And exit.. */
lwp_exit(l);
/*
* XXX Fool the compiler. Making exit1() __noreturn__ is a can
* XXX of worms right now.
*/
for (;;)
;
}
/*
* 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;
/*
* 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:
/*
* 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;
}
}
/* ARGSUSED */
int
sys__lwp_create(struct lwp *l, const struct sys__lwp_create_args *uap, register_t *retval)
{
/* {
syscallarg(const ucontext_t *) ucp;
syscallarg(u_long) flags;
syscallarg(lwpid_t *) new_lwp;
} */
struct proc *p = l->l_proc;
struct lwp *l2;
vaddr_t uaddr;
bool inmem;
ucontext_t *newuc;
int error, lid;
#ifdef KERN_SA
mutex_enter(p->p_lock);
if ((p->p_sflag & (PS_SA | PS_WEXIT)) != 0 || p->p_sa != NULL) {
mutex_exit(p->p_lock);
return EINVAL;
}
mutex_exit(p->p_lock);
#endif
newuc = pool_get(&lwp_uc_pool, PR_WAITOK);
error = copyin(SCARG(uap, ucp), newuc, p->p_emul->e_ucsize);
if (error) {
pool_put(&lwp_uc_pool, newuc);
return error;
}
/* XXX check against resource limits */
inmem = uvm_uarea_alloc(&uaddr);
if (__predict_false(uaddr == 0)) {
pool_put(&lwp_uc_pool, newuc);
return ENOMEM;
}
error = lwp_create(l, p, uaddr, inmem, SCARG(uap, flags) & LWP_DETACHED,
NULL, 0, p->p_emul->e_startlwp, newuc, &l2, l->l_class);
if (error) {
uvm_uarea_free(uaddr, curcpu());
pool_put(&lwp_uc_pool, newuc);
return error;
}
lid = l2->l_lid;
error = copyout(&lid, SCARG(uap, new_lwp), sizeof(lid));
if (error) {
lwp_exit(l2);
pool_put(&lwp_uc_pool, newuc);
return error;
}
/*
* Set the new LWP running, unless the caller has requested that
* it be created in suspended state. If the process is stopping,
* then the LWP is created stopped.
*/
mutex_enter(p->p_lock);
lwp_lock(l2);
if ((SCARG(uap, flags) & LWP_SUSPENDED) == 0 &&
(l->l_flag & (LW_WREBOOT | LW_WSUSPEND | LW_WEXIT)) == 0) {
if (p->p_stat == SSTOP || (p->p_sflag & PS_STOPPING) != 0)
l2->l_stat = LSSTOP;
else {
KASSERT(lwp_locked(l2, l2->l_cpu->ci_schedstate.spc_mutex));
p->p_nrlwps++;
l2->l_stat = LSRUN;
sched_enqueue(l2, false);
}
lwp_unlock(l2);
} else {
l2->l_stat = LSSUSPENDED;
lwp_unlock_to(l2, l2->l_cpu->ci_schedstate.spc_lwplock);
}
mutex_exit(p->p_lock);
return 0;
}
/*
* Fork a kernel thread. Any process can request this to be done.
*/
int
kthread_create(pri_t pri, int flag, struct cpu_info *ci,
void (*func)(void *), void *arg,
lwp_t **lp, const char *fmt, ...)
{
lwp_t *l;
vaddr_t uaddr;
bool inmem;
int error;
va_list ap;
int lc;
inmem = uvm_uarea_alloc(&uaddr);
if (uaddr == 0)
return ENOMEM;
if ((flag & KTHREAD_TS) != 0) {
lc = SCHED_OTHER;
} else {
lc = SCHED_RR;
}
error = lwp_create(&lwp0, &proc0, uaddr, inmem, LWP_DETACHED, NULL,
0, func, arg, &l, lc);
if (error) {
uvm_uarea_free(uaddr, curcpu());
return error;
}
uvm_lwp_hold(l);
if (fmt != NULL) {
l->l_name = kmem_alloc(MAXCOMLEN, KM_SLEEP);
if (l->l_name == NULL) {
lwp_exit(l);
return ENOMEM;
}
va_start(ap, fmt);
vsnprintf(l->l_name, MAXCOMLEN, fmt, ap);
va_end(ap);
}
/*
* Set parameters.
*/
if ((flag & KTHREAD_INTR) != 0) {
KASSERT((flag & KTHREAD_MPSAFE) != 0);
}
if (pri == PRI_NONE) {
if ((flag & KTHREAD_TS) != 0) {
/* Maximum user priority level. */
pri = MAXPRI_USER;
} else {
/* Minimum kernel priority level. */
pri = PRI_KTHREAD;
}
}
mutex_enter(proc0.p_lock);
lwp_lock(l);
l->l_priority = pri;
if (ci != NULL) {
if (ci != l->l_cpu) {
lwp_unlock_to(l, ci->ci_schedstate.spc_mutex);
lwp_lock(l);
}
l->l_pflag |= LP_BOUND;
l->l_cpu = ci;
}
if ((flag & KTHREAD_INTR) != 0)
l->l_pflag |= LP_INTR;
if ((flag & KTHREAD_MPSAFE) == 0)
l->l_pflag &= ~LP_MPSAFE;
/*
* Set the new LWP running, unless the caller has requested
* otherwise.
*/
if ((flag & KTHREAD_IDLE) == 0) {
l->l_stat = LSRUN;
sched_enqueue(l, false);
lwp_unlock(l);
} else
lwp_unlock_to(l, ci->ci_schedstate.spc_lwplock);
/*
* The LWP is not created suspended or stopped and cannot be set
* into those states later, so must be considered runnable.
*/
proc0.p_nrlwps++;
mutex_exit(proc0.p_lock);
/* All done! */
if (lp != NULL)
*lp = l;
return (0);
}
static int
linux_clone_nptl(struct lwp *l, const struct linux_sys_clone_args *uap, register_t *retval)
{
/* {
syscallarg(int) flags;
syscallarg(void *) stack;
syscallarg(void *) parent_tidptr;
syscallarg(void *) tls;
syscallarg(void *) child_tidptr;
} */
struct proc *p;
struct lwp *l2;
struct linux_emuldata *led;
void *parent_tidptr, *tls, *child_tidptr;
struct schedstate_percpu *spc;
vaddr_t uaddr;
lwpid_t lid;
int flags, tnprocs, error;
p = l->l_proc;
flags = SCARG(uap, flags);
parent_tidptr = SCARG(uap, parent_tidptr);
tls = SCARG(uap, tls);
child_tidptr = SCARG(uap, child_tidptr);
tnprocs = atomic_inc_uint_nv(&nprocs);
if (__predict_false(tnprocs >= maxproc) ||
kauth_authorize_process(l->l_cred, KAUTH_PROCESS_FORK, p,
KAUTH_ARG(tnprocs), NULL, NULL) != 0) {
atomic_dec_uint(&nprocs);
return EAGAIN;
}
uaddr = uvm_uarea_alloc();
if (__predict_false(uaddr == 0)) {
atomic_dec_uint(&nprocs);
return ENOMEM;
}
error = lwp_create(l, p, uaddr, LWP_DETACHED | LWP_PIDLID,
SCARG(uap, stack), 0, child_return, NULL, &l2, l->l_class);
if (__predict_false(error)) {
DPRINTF(("%s: lwp_create error=%d\n", __func__, error));
atomic_dec_uint(&nprocs);
uvm_uarea_free(uaddr);
return error;
}
lid = l2->l_lid;
/* LINUX_CLONE_CHILD_CLEARTID: clear TID in child's memory on exit() */
if (flags & LINUX_CLONE_CHILD_CLEARTID) {
led = l2->l_emuldata;
led->led_clear_tid = child_tidptr;
}
/* LINUX_CLONE_PARENT_SETTID: store child's TID in parent's memory */
if (flags & LINUX_CLONE_PARENT_SETTID) {
if ((error = copyout(&lid, parent_tidptr, sizeof(lid))) != 0)
printf("%s: LINUX_CLONE_PARENT_SETTID "
"failed (parent_tidptr = %p tid = %d error=%d)\n",
__func__, parent_tidptr, lid, error);
}
/* LINUX_CLONE_CHILD_SETTID: store child's TID in child's memory */
if (flags & LINUX_CLONE_CHILD_SETTID) {
if ((error = copyout(&lid, child_tidptr, sizeof(lid))) != 0)
printf("%s: LINUX_CLONE_CHILD_SETTID "
"failed (child_tidptr = %p, tid = %d error=%d)\n",
__func__, child_tidptr, lid, error);
}
if (flags & LINUX_CLONE_SETTLS) {
error = LINUX_LWP_SETPRIVATE(l2, tls);
if (error) {
DPRINTF(("%s: LINUX_LWP_SETPRIVATE %d\n", __func__,
error));
lwp_exit(l2);
return error;
}
}
/*
* Set the new LWP running, unless the process is stopping,
* then the LWP is created stopped.
*/
mutex_enter(p->p_lock);
lwp_lock(l2);
spc = &l2->l_cpu->ci_schedstate;
if ((l->l_flag & (LW_WREBOOT | LW_WSUSPEND | LW_WEXIT)) == 0) {
if (p->p_stat == SSTOP || (p->p_sflag & PS_STOPPING) != 0) {
KASSERT(l2->l_wchan == NULL);
l2->l_stat = LSSTOP;
p->p_nrlwps--;
lwp_unlock_to(l2, spc->spc_lwplock);
} else {
KASSERT(lwp_locked(l2, spc->spc_mutex));
l2->l_stat = LSRUN;
sched_enqueue(l2, false);
lwp_unlock(l2);
}
} else {
l2->l_stat = LSSUSPENDED;
p->p_nrlwps--;
lwp_unlock_to(l2, spc->spc_lwplock);
}
mutex_exit(p->p_lock);
retval[0] = lid;
retval[1] = 0;
return 0;
}