NetBSD/sys/kern/kern_sa.c
cl e7045955c7 kernel part of no-syscall upcall stack return: libpthread registers
an offset between ss_sp and struct sa_stackinfo_t (located in struct
__pthread_st) when calling sa_register.  The kernel increments the
sast_gen counter in struct sastack when an upcall stack is used.
libpthread increments the sasi_stackgen counter in struct
sa_stackinfo_t when an upcall stack is freed.  The kernel compares the
two counters to decide if a stack is free or in use.

- add struct sa_stackinfo_t with sasi_stackgen to count stack use in
  userland
- add sast_gen to struct sastack to count stack use in kernel
- add SA_FLAG_STACKINFO to enable the stackinfo_offset argument in the
  sa_register syscall
- add sa_stackinfo_offset to struct sadata for offset between ss_sp
  and struct sa_stackinfo_t
- add ssize_t stackinfo_offset argument to sa_register, initialize
  struct sadata's sa_stackinfo_offset from it if SA_FLAG_STACKINFO is
  set
- add sa_getstack, sa_getstack0, sa_stackused and sa_setstackfree
  functions to find/use/free upcall stacks and use these where
  appropriate
- don't record stack for upcall in sa_upcall0
- pass sau to sa_switchcall instead of l2 (l2 = curlwp in sa_switchcall)
- add sa_vp_blocker to struct sadata to pass recently blocked lwp to
  sa_switchcall
- delay finding a stack for blocked upcalls to sa_switchcall
- add sa_stacknext to struct sadata pointing to next most likely free
  upcall stack; also g/c sa_stackslist in struct sadata and sast_list
  in struct sastack
- add L_SA_WOKEN flag: LWP is on sa_woken queue
- add L_SA_RECYCLE flag: LWP should be recycled in sa_setwoken
- replace l_upcallstack with L_SA_WOKEN/L_SA_RECYCLE/L_SA_BLOCKING
  flags
- g/c now unused sast_blocker in struct sastack
- make sa_switchcall, sa_upcall0 and sa_upcall_getstate static in
  kern_sa.c
- call sa_upcall_userret only once in userret
- split sa_makeupcalls out of sa_upcall_userret and use to process
  the sa_upcalls queue
- on process exit: mark LWPs sleeping in saunblock interruptible; also
  there are no LWPs sleeping on l->l_upcallstack anymore; also clear
  sa_wokenq_head to prevent unblocked upcalls

additional changes:
- cleanup timerupcall sa_vp == curlwp check
- add check in sa_yield if we didn't block on our way here and we
  wouldn't any longer be the LWP on the VP
- invalidate sa_vp_ofaultaddr after resolving pagefault
2004-01-02 18:52:17 +00:00

1739 lines
42 KiB
C

/* $NetBSD: kern_sa.c,v 1.47 2004/01/02 18:52:17 cl Exp $ */
/*-
* Copyright (c) 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Nathan J. Williams.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_sa.c,v 1.47 2004/01/02 18:52:17 cl Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/pool.h>
#include <sys/proc.h>
#include <sys/types.h>
#include <sys/ucontext.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/sa.h>
#include <sys/savar.h>
#include <sys/syscallargs.h>
#include <uvm/uvm_extern.h>
static __inline int sa_stackused(struct sastack *, struct sadata *);
static __inline void sa_setstackfree(struct sastack *, struct sadata *);
static struct sastack *sa_getstack(struct sadata *);
static __inline struct sastack *sa_getstack0(struct sadata *);
static __inline int sast_compare(struct sastack *, struct sastack *);
static void sa_setwoken(struct lwp *);
static void sa_switchcall(void *);
static int sa_newcachelwp(struct lwp *);
static __inline void sa_makeupcalls(struct lwp *);
static struct lwp *sa_vp_repossess(struct lwp *l);
static __inline int sa_pagefault(struct lwp *, ucontext_t *);
static int sa_upcall0(struct lwp *, int, struct lwp *, struct lwp *,
size_t, void *, struct sadata_upcall *);
static void sa_upcall_getstate(union sau_state *, struct lwp *);
MALLOC_DEFINE(M_SA, "sa", "Scheduler activations");
#define SA_DEBUG
#ifdef SA_DEBUG
#define DPRINTF(x) do { if (sadebug) printf x; } while (0)
#define DPRINTFN(n,x) do { if (sadebug & (1<<(n-1))) printf x; } while (0)
int sadebug = 0;
#else
#define DPRINTF(x)
#define DPRINTFN(n,x)
#endif
#define SA_LWP_STATE_LOCK(l, f) do { \
(f) = (l)->l_flag; \
(l)->l_flag &= ~L_SA; \
} while (/*CONSTCOND*/ 0)
#define SA_LWP_STATE_UNLOCK(l, f) do { \
(l)->l_flag |= (f) & L_SA; \
} while (/*CONSTCOND*/ 0)
SPLAY_PROTOTYPE(sasttree, sastack, sast_node, sast_compare);
SPLAY_GENERATE(sasttree, sastack, sast_node, sast_compare);
/*
* sadata_upcall_alloc:
*
* Allocate an sadata_upcall structure.
*/
struct sadata_upcall *
sadata_upcall_alloc(int waitok)
{
/* XXX zero the memory? */
return (pool_get(&saupcall_pool, waitok ? PR_WAITOK : PR_NOWAIT));
}
/*
* sadata_upcall_free:
*
* Free an sadata_upcall structure, and any associated
* argument data.
*/
void
sadata_upcall_free(struct sadata_upcall *sau)
{
extern struct pool siginfo_pool; /* XXX Ew. */
/*
* XXX We have to know what the origin of sau_arg is
* XXX in order to do the right thing, here. Sucks
* XXX to be a non-garbage-collecting kernel.
*/
if (sau->sau_arg) {
switch (sau->sau_type) {
case SA_UPCALL_SIGNAL:
case SA_UPCALL_SIGEV:
pool_put(&siginfo_pool, sau->sau_arg);
break;
default:
panic("sadata_free: unknown type of sau_arg: %d",
sau->sau_type);
}
}
pool_put(&saupcall_pool, sau);
}
int
sys_sa_register(struct lwp *l, void *v, register_t *retval)
{
struct sys_sa_register_args /* {
syscallarg(sa_upcall_t) new;
syscallarg(sa_upcall_t *) old;
syscallarg(int) flags;
syscallarg(ssize_t) stackinfo_offset;
} */ *uap = v;
struct proc *p = l->l_proc;
struct sadata *sa;
sa_upcall_t prev;
int error;
if (p->p_sa == NULL) {
/* Allocate scheduler activations data structure */
sa = pool_get(&sadata_pool, PR_WAITOK);
/* Initialize. */
memset(sa, 0, sizeof(*sa));
simple_lock_init(&sa->sa_lock);
sa->sa_flag = SCARG(uap, flags) & SA_FLAG_ALL;
sa->sa_vp = NULL;
sa->sa_wokenq_head = NULL;
sa->sa_concurrency = 1;
SPLAY_INIT(&sa->sa_stackstree);
sa->sa_stacknext = NULL;
if (SCARG(uap, flags) & SA_FLAG_STACKINFO)
sa->sa_stackinfo_offset = SCARG(uap, stackinfo_offset);
else
sa->sa_stackinfo_offset = 0;
sa->sa_nstacks = 0;
sa->sa_vp_faultaddr = 0;
sa->sa_vp_ofaultaddr = 0;
LIST_INIT(&sa->sa_lwpcache);
SIMPLEQ_INIT(&sa->sa_upcalls);
p->p_sa = sa;
sa_newcachelwp(l);
}
prev = p->p_sa->sa_upcall;
p->p_sa->sa_upcall = SCARG(uap, new);
if (SCARG(uap, old)) {
error = copyout(&prev, SCARG(uap, old),
sizeof(prev));
if (error)
return (error);
}
return (0);
}
void
sa_release(struct proc *p)
{
struct sadata *sa;
struct sastack *sast, *next;
sa = p->p_sa;
KDASSERT(sa != NULL);
for (sast = SPLAY_MIN(sasttree, &sa->sa_stackstree); sast != NULL;
sast = next) {
next = SPLAY_NEXT(sasttree, &sa->sa_stackstree, sast);
SPLAY_REMOVE(sasttree, &sa->sa_stackstree, sast);
pool_put(&sastack_pool, sast);
}
p->p_flag &= ~P_SA;
pool_put(&sadata_pool, sa);
p->p_sa = NULL;
}
static __inline int
sa_stackused(struct sastack *sast, struct sadata *sa)
{
unsigned int gen;
if (copyin((void *)&((struct sa_stackinfo_t *)
((char *)sast->sast_stack.ss_sp +
sa->sa_stackinfo_offset))->sasi_stackgen,
&gen, sizeof(unsigned int)) != 0) {
#ifdef DIAGNOSTIC
printf("sa_stackused: couldn't copyin sasi_stackgen");
#endif
sigexit(curlwp, SIGILL);
/* NOTREACHED */
}
return (sast->sast_gen != gen);
}
static __inline void
sa_setstackfree(struct sastack *sast, struct sadata *sa)
{
if (copyin((void *)&((struct sa_stackinfo_t *)
((char *)sast->sast_stack.ss_sp +
sa->sa_stackinfo_offset))->sasi_stackgen,
&sast->sast_gen, sizeof(unsigned int)) != 0) {
#ifdef DIAGNOSTIC
printf("sa_setstackfree: couldn't copyin sasi_stackgen");
#endif
sigexit(curlwp, SIGILL);
/* NOTREACHED */
}
}
/*
* Find next free stack, starting at sa->sa_stacknext.
*/
static struct sastack *
sa_getstack(struct sadata *sa)
{
struct sastack *sast;
SCHED_ASSERT_UNLOCKED();
if ((sast = sa->sa_stacknext) == NULL || sa_stackused(sast, sa))
sast = sa_getstack0(sa);
if (sast == NULL)
return NULL;
sast->sast_gen++;
return sast;
}
static __inline struct sastack *
sa_getstack0(struct sadata *sa)
{
struct sastack *start;
if (sa->sa_stacknext == NULL) {
sa->sa_stacknext = SPLAY_MIN(sasttree, &sa->sa_stackstree);
if (sa->sa_stacknext == NULL)
return NULL;
}
start = sa->sa_stacknext;
while (sa_stackused(sa->sa_stacknext, sa)) {
sa->sa_stacknext = SPLAY_NEXT(sasttree, &sa->sa_stackstree,
sa->sa_stacknext);
if (sa->sa_stacknext == NULL)
sa->sa_stacknext = SPLAY_MIN(sasttree,
&sa->sa_stackstree);
if (sa->sa_stacknext == start)
return NULL;
}
return sa->sa_stacknext;
}
static __inline int
sast_compare(struct sastack *a, struct sastack *b)
{
if ((vaddr_t)a->sast_stack.ss_sp + a->sast_stack.ss_size <=
(vaddr_t)b->sast_stack.ss_sp)
return (-1);
if ((vaddr_t)a->sast_stack.ss_sp >=
(vaddr_t)b->sast_stack.ss_sp + b->sast_stack.ss_size)
return (1);
return (0);
}
int
sys_sa_stacks(struct lwp *l, void *v, register_t *retval)
{
struct sys_sa_stacks_args /* {
syscallarg(int) num;
syscallarg(stack_t *) stacks;
} */ *uap = v;
struct sadata *sa = l->l_proc->p_sa;
struct sastack *sast, newsast;
int count, error, f, i;
/* We have to be using scheduler activations */
if (sa == NULL)
return (EINVAL);
count = SCARG(uap, num);
if (count < 0)
return (EINVAL);
SA_LWP_STATE_LOCK(l, f);
error = 0;
for (i = 0; i < count; i++) {
error = copyin(SCARG(uap, stacks) + i, &newsast.sast_stack,
sizeof(stack_t));
if (error) {
count = i;
break;
}
if ((sast = SPLAY_FIND(sasttree, &sa->sa_stackstree, &newsast))) {
DPRINTFN(9, ("sa_stacks(%d.%d) returning stack %p\n",
l->l_proc->p_pid, l->l_lid,
newsast.sast_stack.ss_sp));
if (sa_stackused(sast, sa) == 0) {
count = i;
error = EEXIST;
break;
}
} else if (sa->sa_nstacks >= SA_MAXNUMSTACKS * sa->sa_concurrency) {
DPRINTFN(9, ("sa_stacks(%d.%d) already using %d stacks\n",
l->l_proc->p_pid, l->l_lid,
SA_MAXNUMSTACKS * sa->sa_concurrency));
count = i;
error = ENOMEM;
break;
} else {
DPRINTFN(9, ("sa_stacks(%d.%d) adding stack %p\n",
l->l_proc->p_pid, l->l_lid,
newsast.sast_stack.ss_sp));
sast = pool_get(&sastack_pool, PR_WAITOK);
sast->sast_stack = newsast.sast_stack;
SPLAY_INSERT(sasttree, &sa->sa_stackstree, sast);
sa->sa_nstacks++;
}
sa_setstackfree(sast, sa);
}
SA_LWP_STATE_UNLOCK(l, f);
*retval = count;
return (error);
}
int
sys_sa_enable(struct lwp *l, void *v, register_t *retval)
{
struct proc *p = l->l_proc;
struct sadata *sa = p->p_sa;
int error;
DPRINTF(("sys_sa_enable(%d.%d)\n", l->l_proc->p_pid,
l->l_lid));
/* We have to be using scheduler activations */
if (sa == NULL)
return (EINVAL);
if (p->p_flag & P_SA) /* Already running! */
return (EBUSY);
error = sa_upcall(l, SA_UPCALL_NEWPROC, l, NULL, 0, NULL);
if (error)
return (error);
/* Assign this LWP to the virtual processor */
sa->sa_vp = l;
p->p_flag |= P_SA;
l->l_flag |= L_SA; /* We are now an activation LWP */
/* This will not return to the place in user space it came from. */
return (0);
}
int
sys_sa_setconcurrency(struct lwp *l, void *v, register_t *retval)
{
struct sys_sa_setconcurrency_args /* {
syscallarg(int) concurrency;
} */ *uap = v;
struct sadata *sa = l->l_proc->p_sa;
DPRINTF(("sys_sa_concurrency(%d.%d)\n", l->l_proc->p_pid,
l->l_lid));
/* We have to be using scheduler activations */
if (sa == NULL)
return (EINVAL);
if (SCARG(uap, concurrency) < 1)
return (EINVAL);
*retval = sa->sa_concurrency;
/*
* Concurrency greater than the number of physical CPUs does
* not make sense.
* XXX Should we ever support hot-plug CPUs, this will need
* adjustment.
*/
sa->sa_concurrency = min(SCARG(uap, concurrency), 1 /* XXX ncpus */);
return (0);
}
int
sys_sa_yield(struct lwp *l, void *v, register_t *retval)
{
struct proc *p = l->l_proc;
if (p->p_sa == NULL || !(p->p_flag & P_SA)) {
DPRINTFN(1,("sys_sa_yield(%d.%d) proc %p not SA (p_sa %p, flag %s)\n",
p->p_pid, l->l_lid, p, p->p_sa, p->p_flag & P_SA ? "T" : "F"));
return (EINVAL);
}
sa_yield(l);
return (0);
}
void
sa_yield(struct lwp *l)
{
struct proc *p = l->l_proc;
struct sadata *sa = p->p_sa;
int ret, s;
#if defined(MULTIPROCESSOR)
KDASSERT(l->l_flag & L_BIGLOCK);
#endif
if (sa->sa_vp != l) {
/*
* We lost the VP on our way here, this happens for
* instance when we sleep in systrace. We'll try to
* return to userland but the blocked upcall from the
* sleep will probably already have called
* sa_unblockyield() and we'll be recycled in
* sa_setwoken().
*/
DPRINTFN(1,("sa_yield(%d.%d) lost VP\n",
p->p_pid, l->l_lid));
KDASSERT(l->l_flag & L_SA_BLOCKING);
return;
}
/*
* If we're the last running LWP, stick around to recieve
* signals.
*/
KDASSERT((l->l_flag & L_SA_YIELD) == 0);
DPRINTFN(1,("sa_yield(%d.%d) going dormant\n",
p->p_pid, l->l_lid));
/*
* A signal will probably wake us up. Worst case, the upcall
* happens and just causes the process to yield again.
*/
s = splsched(); /* Protect from timer expirations */
KDASSERT(sa->sa_vp == l);
/*
* If we were told to make an upcall or exit before
* the splsched(), make sure we process it instead of
* going to sleep. It might make more sense for this to
* be handled inside of tsleep....
*/
ret = 0;
while (ret == 0 && p->p_userret == NULL &&
(l->l_flag & L_SA_UPCALL) == 0) {
l->l_flag |= L_SA_YIELD;
ret = tsleep((caddr_t) l, PUSER | PCATCH, "sawait", 0);
l->l_flag &= ~L_SA_YIELD;
if (p->p_flag & P_WEXIT)
lwp_exit(l);
KDASSERT(sa->sa_vp == l);
}
splx(s);
DPRINTFN(1,("sa_yield(%d.%d) returned\n",
p->p_pid, l->l_lid));
}
int
sys_sa_preempt(struct lwp *l, void *v, register_t *retval)
{
/* XXX Implement me. */
return (ENOSYS);
}
/* XXX Hm, naming collision. */
void
sa_preempt(struct lwp *l)
{
struct proc *p = l->l_proc;
struct sadata *sa = p->p_sa;
/*
* Defer saving the lwp's state because on some ports
* preemption can occur between generating an unblocked upcall
* and processing the upcall queue.
*/
if (sa->sa_flag & SA_FLAG_PREEMPT)
sa_upcall(l, SA_UPCALL_PREEMPTED | SA_UPCALL_DEFER_EVENT,
l, NULL, 0, NULL);
}
/*
* Help userspace library resolve locks and critical sections:
* - return if the unblocked upcall has already been delivered.
* This case is usually already detected in userspace.
* - recycles the calling LWP and its stack if it was not preempted
* and the unblocked upcall was not yet delivered. Put the sa_id
* LWP on the VP and wait until it unblocks or switch to it if it's
* ready. There will be no unblocked upcall.
* - recycles the blocked LWP if up_preempted == NULL. This is used
* if the blocked LWP is an idle thread and we don't care for the
* unblocked upcall.
* - otherwise, wait for the blocked LWP to get ready. The unblocked
* upcall is delivered when we return.
* This is used if a thread blocks (mostly because of a pagefault) and
* is in a critical section in the userspace library and the critical
* section resolving code cannot continue until the blocked thread is
* unblocked.
*/
int
sys_sa_unblockyield(struct lwp *l, void *v, register_t *retval)
{
struct sys_sa_unblockyield_args /* {
syscallarg(int) sa_id;
syscallarg(void *) up_preempted;
syscallarg(stack_t *) up_stack;
} */ *uap = v;
struct sadata *sa = l->l_proc->p_sa;
struct proc *p = l->l_proc;
struct lwp *l2, **hp;
struct sastack *sast, up_sast;
int error, f, s;
void *preempted;
if (sa == NULL)
return (EINVAL);
SA_LWP_STATE_LOCK(l, f);
if (SCARG(uap, up_stack) != NULL) {
error = copyin(SCARG(uap, up_stack), &up_sast.sast_stack,
sizeof(stack_t));
if (error) {
SA_LWP_STATE_UNLOCK(l, f);
return (error);
}
}
if (SCARG(uap, up_preempted) != NULL) {
error = copyin(SCARG(uap, up_preempted), &preempted,
sizeof(void *));
if (error) {
SA_LWP_STATE_UNLOCK(l, f);
return (error);
}
}
SA_LWP_STATE_UNLOCK(l, f);
SCHED_LOCK(s);
LIST_FOREACH(l2, &p->p_lwps, l_sibling) {
if (l2->l_lid == SCARG(uap, sa_id)) {
break;
}
}
if (l2 == NULL || (l2->l_flag & L_SA_BLOCKING) == 0) {
/* just return, prevented in userland most of the time */
DPRINTFN(11,("sys_sa_unblockyield(%d.%d) unblocked upcall for %d done\n",
p->p_pid, l->l_lid, SCARG(uap, sa_id)));
KDASSERT(preempted != NULL);
} else if (SCARG(uap, up_preempted) == NULL) {
/* recycle blocked LWP */
DPRINTFN(11,("sys_sa_unblockyield(%d.%d) recycle %d "
"(was %sready)\n",
p->p_pid, l->l_lid, l2->l_lid,
(l2->l_flag & L_SA_WOKEN) ? "" : "not "));
if (l2->l_flag & L_SA_WOKEN) {
/*
* l2 is on the wokenq, remove it and put l2
* in the cache
*/
hp = &sa->sa_wokenq_head;
while (*hp != l2)
hp = &(*hp)->l_forw;
*hp = l2->l_forw;
if (sa->sa_wokenq_tailp == &l2->l_forw)
sa->sa_wokenq_tailp = hp;
l2->l_flag &= ~(L_SA_BLOCKING|L_SA_WOKEN);
sa_putcachelwp(p, l2); /* PHOLD from sa_setwoken */
} else
/* let sa_setwoken put it in the cache */
l2->l_flag |= L_SA_RECYCLE;
} else if (preempted != NULL) {
/* wait for the blocked LWP to get ready, then return */
DPRINTFN(11,("sys_sa_unblockyield(%d.%d) waiting for %d "
"(was %sready) upcall stack %p\n",
p->p_pid, l->l_lid, l2->l_lid,
(l2->l_flag & L_SA_WOKEN) ? "" :
"not ", up_sast.sast_stack.ss_sp));
if ((l2->l_flag & L_SA_WOKEN) == 0) {
l2->l_flag |= L_SA_WOKEN;
SCHED_UNLOCK(s); /* XXXcl we're still holding
* the kernel lock, is that
* good enough? */
SA_LWP_STATE_LOCK(l, f);
tsleep((caddr_t) sa, PWAIT, "saunblock", 0);
SA_LWP_STATE_UNLOCK(l, f);
if (p->p_flag & P_WEXIT)
lwp_exit(l);
return(0);
}
} else {
/* recycle calling LWP and resume blocked LWP */
DPRINTFN(11,("sys_sa_unblockyield(%d.%d) resuming %d "
"(is %sready) upcall stack %p\n",
p->p_pid, l->l_lid, l2->l_lid,
(l2->l_flag & L_SA_WOKEN) ? "" :
"not ", up_sast.sast_stack.ss_sp));
sa->sa_vp = l2;
l2->l_flag &= ~L_SA_BLOCKING;
sast = SPLAY_FIND(sasttree, &sa->sa_stackstree, &up_sast);
if (sast == NULL) {
SCHED_UNLOCK(s);
return(ESRCH);
}
sa_setstackfree(sast, sa);
if (l2->l_flag & L_SA_WOKEN) {
/*
* l2 is on the wokenq, remove it and
* continue l2
*/
hp = &sa->sa_wokenq_head;
while (*hp != l2)
hp = &(*hp)->l_forw;
*hp = l2->l_forw;
if (sa->sa_wokenq_tailp == &l2->l_forw)
sa->sa_wokenq_tailp = hp;
l2->l_flag &= ~L_SA_WOKEN;
setrunnable(l2);
PRELE(l2); /* PHOLD from sa_setwoken */
} else
l2 = NULL; /* don't continue l2 yet */
p->p_nrlwps--;
PHOLD(l);
sa_putcachelwp(p, l);
mi_switch(l, l2);
/* mostly NOTREACHED */
SCHED_ASSERT_UNLOCKED();
splx(s);
KDASSERT(p->p_flag & P_WEXIT);
lwp_exit(l);
}
SCHED_UNLOCK(s);
return (0);
}
/*
* Set up the user-level stack and trapframe to do an upcall.
*
* NOTE: This routine WILL FREE "arg" in the case of failure! Callers
* should not touch the "arg" pointer once calling sa_upcall().
*/
int
sa_upcall(struct lwp *l, int type, struct lwp *event, struct lwp *interrupted,
size_t argsize, void *arg)
{
struct sadata_upcall *sau;
struct sadata *sa = l->l_proc->p_sa;
struct sastack *sast;
int error, f;
/* XXX prevent recursive upcalls if we sleep formemory */
SA_LWP_STATE_LOCK(l, f);
sast = sa_getstack(sa);
sau = sadata_upcall_alloc(1);
SA_LWP_STATE_UNLOCK(l, f);
if (sast == NULL) {
/* assign to assure that it gets freed */
sau->sau_type = type & SA_UPCALL_TYPE_MASK;
sau->sau_arg = arg;
sadata_upcall_free(sau);
return (ENOMEM);
}
DPRINTFN(9,("sa_upcall(%d.%d) using stack %p\n",
l->l_proc->p_pid, l->l_lid, sast->sast_stack.ss_sp));
error = sa_upcall0(l, type, event, interrupted, argsize, arg, sau);
if (error) {
sadata_upcall_free(sau);
sa_setstackfree(sast, sa);
return (error);
}
sau->sau_stack = sast->sast_stack;
SIMPLEQ_INSERT_TAIL(&sa->sa_upcalls, sau, sau_next);
l->l_flag |= L_SA_UPCALL;
return (0);
}
static int
sa_upcall0(struct lwp *l, int type, struct lwp *event, struct lwp *interrupted,
size_t argsize, void *arg, struct sadata_upcall *sau)
{
KDASSERT((event == NULL) || (event != interrupted));
sau->sau_flags = 0;
sau->sau_type = type & SA_UPCALL_TYPE_MASK;
sau->sau_argsize = argsize;
sau->sau_arg = arg;
if (type & SA_UPCALL_DEFER_EVENT) {
sau->sau_event.ss_deferred.ss_lwp = event;
sau->sau_flags |= SAU_FLAG_DEFERRED_EVENT;
} else
sa_upcall_getstate(&sau->sau_event, event);
if (type & SA_UPCALL_DEFER_INTERRUPTED) {
sau->sau_interrupted.ss_deferred.ss_lwp = interrupted;
sau->sau_flags |= SAU_FLAG_DEFERRED_INTERRUPTED;
} else
sa_upcall_getstate(&sau->sau_interrupted, interrupted);
return (0);
}
static void
sa_upcall_getstate(union sau_state *ss, struct lwp *l)
{
if (l) {
getucontext(l, &ss->ss_captured.ss_ctx);
ss->ss_captured.ss_sa.sa_context = (ucontext_t *)
(intptr_t)((_UC_MACHINE_SP(&ss->ss_captured.ss_ctx) -
sizeof(ucontext_t))
#ifdef _UC_UCONTEXT_ALIGN
& _UC_UCONTEXT_ALIGN
#endif
);
ss->ss_captured.ss_sa.sa_id = l->l_lid;
ss->ss_captured.ss_sa.sa_cpu = 0; /* XXX extract from l_cpu */
} else
ss->ss_captured.ss_sa.sa_context = NULL;
}
/*
* Detect double pagefaults and pagefaults on upcalls.
* - double pagefaults are detected by comparing the previous faultaddr
* against the current faultaddr
* - pagefaults on upcalls are detected by checking if the userspace
* thread is running on an upcall stack
*/
static __inline int
sa_pagefault(struct lwp *l, ucontext_t *l_ctx)
{
struct proc *p;
struct sadata *sa;
struct sastack sast;
p = l->l_proc;
sa = p->p_sa;
KDASSERT(sa->sa_vp == l);
if (sa->sa_vp_faultaddr == sa->sa_vp_ofaultaddr) {
DPRINTFN(10,("sa_pagefault(%d.%d) double page fault\n",
p->p_pid, l->l_lid));
return 1;
}
sast.sast_stack.ss_sp = (void *)(intptr_t)_UC_MACHINE_SP(l_ctx);
sast.sast_stack.ss_size = 1;
if (SPLAY_FIND(sasttree, &sa->sa_stackstree, &sast)) {
DPRINTFN(10,("sa_pagefault(%d.%d) upcall page fault\n",
p->p_pid, l->l_lid));
return 1;
}
sa->sa_vp_ofaultaddr = sa->sa_vp_faultaddr;
return 0;
}
/*
* Called by tsleep(). Block current LWP and switch to another.
*
* WE ARE NOT ALLOWED TO SLEEP HERE! WE ARE CALLED FROM WITHIN
* TSLEEP() ITSELF! We are called with sched_lock held, and must
* hold it right through the mi_switch() call.
*/
void
sa_switch(struct lwp *l, int type)
{
struct proc *p = l->l_proc;
struct sadata *sa = p->p_sa;
struct sadata_upcall *sau;
struct lwp *l2;
int error, s;
DPRINTFN(4,("sa_switch(%d.%d type %d VP %d)\n", p->p_pid, l->l_lid,
type, sa->sa_vp ? sa->sa_vp->l_lid : 0));
SCHED_ASSERT_LOCKED();
if (p->p_flag & P_WEXIT) {
mi_switch(l, NULL);
return;
}
if (l->l_flag & L_SA_YIELD) {
/*
* Case 0: we're blocking in sa_yield
*/
if (sa->sa_wokenq_head == NULL) {
l->l_flag |= L_SA_IDLE;
mi_switch(l, NULL);
} else {
/* make us running again. */
unsleep(l);
l->l_stat = LSONPROC;
l->l_proc->p_nrlwps++;
s = splsched();
SCHED_UNLOCK(s);
}
return;
} else if (sa->sa_vp == l) {
/*
* Case 1: we're blocking for the first time; generate
* a SA_BLOCKED upcall and allocate resources for the
* UNBLOCKED upcall.
*/
/*
* The process of allocating a new LWP could cause
* sleeps. We're called from inside sleep, so that
* would be Bad. Therefore, we must use a cached new
* LWP. The first thing that this new LWP must do is
* allocate another LWP for the cache. */
l2 = sa_getcachelwp(p);
if (l2 == NULL) {
/* XXXSMP */
/* No upcall for you! */
/* XXX The consequences of this are more subtle and
* XXX the recovery from this situation deserves
* XXX more thought.
*/
/* XXXUPSXXX Should only happen with concurrency > 1 */
#ifdef DIAGNOSTIC
printf("sa_switch(%d.%d): no cached LWP for upcall.\n",
p->p_pid, l->l_lid);
#endif
mi_switch(l, NULL);
return;
}
/*
* XXX We need to allocate the sadata_upcall structure here,
* XXX since we can't sleep while waiting for memory inside
* XXX sa_upcall(). It would be nice if we could safely
* XXX allocate the sadata_upcall structure on the stack, here.
*/
sau = sadata_upcall_alloc(0);
if (sau == NULL) {
#ifdef DIAGNOSTIC
printf("sa_switch(%d.%d): couldn't allocate upcall data.\n",
p->p_pid, l->l_lid);
#endif
sa_putcachelwp(p, l2); /* PHOLD from sa_getcachelwp */
mi_switch(l, NULL);
return;
}
cpu_setfunc(l2, sa_switchcall, sau);
error = sa_upcall0(l2, SA_UPCALL_BLOCKED, l, NULL, 0, NULL,
sau);
if (error) {
#ifdef DIAGNOSTIC
printf("sa_switch(%d.%d): Error %d from sa_upcall()\n",
p->p_pid, l->l_lid, error);
#endif
sa_putcachelwp(p, l2); /* PHOLD from sa_getcachelwp */
mi_switch(l, NULL);
return;
}
/*
* Perform the double/upcall pagefault check.
* We do this only here since we need l's ucontext to
* get l's userspace stack. sa_upcall0 above has saved
* it for us.
* The L_SA_PAGEFAULT flag is set in the MD
* pagefault code to indicate a pagefault. The MD
* pagefault code also saves the faultaddr for us.
*/
if ((l->l_flag & L_SA_PAGEFAULT) && sa_pagefault(l,
&sau->sau_event.ss_captured.ss_ctx) != 0) {
sadata_upcall_free(sau);
sa_putcachelwp(p, l2); /* PHOLD from sa_getcachelwp */
mi_switch(l, NULL);
DPRINTFN(10,("sa_switch(%d.%d) page fault resolved\n",
p->p_pid, l->l_lid));
if (sa->sa_vp_faultaddr == sa->sa_vp_ofaultaddr)
sa->sa_vp_ofaultaddr = -1;
return;
}
DPRINTFN(8,("sa_switch(%d.%d) blocked upcall %d\n",
p->p_pid, l->l_lid, l2->l_lid));
l->l_flag |= L_SA_BLOCKING;
l2->l_priority = l2->l_usrpri;
sa->sa_vp_blocker = l;
sa->sa_vp = l2;
setrunnable(l2);
PRELE(l2); /* Remove the artificial hold-count */
KDASSERT(l2 != l);
} else if (sa->sa_vp != NULL) {
/*
* Case 2: We've been woken up while another LWP was
* on the VP, but we're going back to sleep without
* having returned to userland and delivering the
* SA_UNBLOCKED upcall (select and poll cause this
* kind of behavior a lot). We just switch back to the
* LWP that had been running and let it have another
* go. If the LWP on the VP was idling, don't make it
* run again, though.
*/
if (sa->sa_vp->l_flag & L_SA_YIELD)
l2 = NULL;
else {
l2 = sa->sa_vp; /* XXXUPSXXX Unfair advantage for l2 ? */
if((l2->l_stat != LSRUN) || ((l2->l_flag & L_INMEM) == 0))
l2 = NULL;
}
} else {
/* NOTREACHED */
panic("sa_vp empty");
}
DPRINTFN(4,("sa_switch(%d.%d) switching to LWP %d.\n",
p->p_pid, l->l_lid, l2 ? l2->l_lid : 0));
mi_switch(l, l2);
DPRINTFN(4,("sa_switch(%d.%d flag %x) returned.\n",
p->p_pid, l->l_lid, l->l_flag));
KDASSERT(l->l_wchan == 0);
SCHED_ASSERT_UNLOCKED();
}
static void
sa_switchcall(void *arg)
{
struct lwp *l, *l2;
struct proc *p;
struct sadata *sa;
struct sadata_upcall *sau;
struct sastack *sast;
int s;
l2 = curlwp;
p = l2->l_proc;
sa = p->p_sa;
if (p->p_flag & P_WEXIT)
lwp_exit(l2);
l = sa->sa_vp_blocker;
KDASSERT(sa->sa_vp == l2);
sau = arg;
DPRINTFN(6,("sa_switchcall(%d.%d)\n", p->p_pid, l2->l_lid));
l2->l_flag &= ~L_SA;
if (LIST_EMPTY(&sa->sa_lwpcache)) {
/* Allocate the next cache LWP */
DPRINTFN(6,("sa_switchcall(%d.%d) allocating LWP\n",
p->p_pid, l2->l_lid));
sa_newcachelwp(l2);
}
sast = sa_getstack(sa);
if (sast) {
sau->sau_stack = sast->sast_stack;
SIMPLEQ_INSERT_TAIL(&sa->sa_upcalls, sau, sau_next);
l2->l_flag |= L_SA|L_SA_UPCALL;
} else {
#ifdef DIAGNOSTIC
printf("sa_switchcall(%d.%d flag %x): Not enough stacks.\n",
p->p_pid, l->l_lid, l->l_flag);
#endif
sadata_upcall_free(sau);
PHOLD(l2);
SCHED_LOCK(s);
sa_putcachelwp(p, l2); /* sets L_SA */
sa->sa_vp = l;
mi_switch(l2, NULL);
/* mostly NOTREACHED */
SCHED_ASSERT_UNLOCKED();
splx(s);
}
upcallret(l2);
}
static int
sa_newcachelwp(struct lwp *l)
{
struct proc *p;
struct lwp *l2;
vaddr_t uaddr;
boolean_t inmem;
int s;
p = l->l_proc;
if (p->p_flag & P_WEXIT)
return (0);
inmem = uvm_uarea_alloc(&uaddr);
if (__predict_false(uaddr == 0)) {
return (ENOMEM);
} else {
newlwp(l, p, uaddr, inmem, 0, NULL, 0, child_return, 0, &l2);
/* We don't want this LWP on the process's main LWP list, but
* newlwp helpfully puts it there. Unclear if newlwp should
* be tweaked.
*/
PHOLD(l2);
SCHED_LOCK(s);
sa_putcachelwp(p, l2);
SCHED_UNLOCK(s);
}
return (0);
}
/*
* Take a normal process LWP and place it in the SA cache.
* LWP must not be running!
*/
void
sa_putcachelwp(struct proc *p, struct lwp *l)
{
struct sadata *sa;
SCHED_ASSERT_LOCKED();
sa = p->p_sa;
LIST_REMOVE(l, l_sibling);
p->p_nlwps--;
l->l_stat = LSSUSPENDED;
l->l_flag |= (L_DETACHED | L_SA);
/* XXX lock sadata */
DPRINTFN(5,("sa_putcachelwp(%d.%d) Adding LWP %d to cache\n",
p->p_pid, curlwp->l_lid, l->l_lid));
LIST_INSERT_HEAD(&sa->sa_lwpcache, l, l_sibling);
sa->sa_ncached++;
/* XXX unlock */
}
/*
* Fetch a LWP from the cache.
*/
struct lwp *
sa_getcachelwp(struct proc *p)
{
struct sadata *sa;
struct lwp *l;
SCHED_ASSERT_LOCKED();
l = NULL;
sa = p->p_sa;
/* XXX lock sadata */
if (sa->sa_ncached > 0) {
sa->sa_ncached--;
l = LIST_FIRST(&sa->sa_lwpcache);
LIST_REMOVE(l, l_sibling);
LIST_INSERT_HEAD(&p->p_lwps, l, l_sibling);
p->p_nlwps++;
DPRINTFN(5,("sa_getcachelwp(%d.%d) Got LWP %d from cache.\n",
p->p_pid, curlwp->l_lid, l->l_lid));
}
/* XXX unlock */
return l;
}
void
sa_unblock_userret(struct lwp *l)
{
struct proc *p;
struct lwp *l2;
struct sadata *sa;
struct sadata_upcall *sau;
struct sastack *sast;
int f, s;
p = l->l_proc;
sa = p->p_sa;
if (p->p_flag & P_WEXIT)
return;
SCHED_ASSERT_UNLOCKED();
KERNEL_PROC_LOCK(l);
SA_LWP_STATE_LOCK(l, f);
DPRINTFN(7,("sa_unblock_userret(%d.%d %x) \n", p->p_pid, l->l_lid,
l->l_flag));
sa_setwoken(l);
/* maybe NOTREACHED */
SCHED_LOCK(s);
if (l != sa->sa_vp) {
/* Invoke an "unblocked" upcall */
DPRINTFN(8,("sa_unblock_userret(%d.%d) unblocking\n",
p->p_pid, l->l_lid));
l2 = sa_vp_repossess(l);
SCHED_UNLOCK(s);
if (l2 == NULL)
lwp_exit(l);
sast = sa_getstack(sa);
if (p->p_flag & P_WEXIT)
lwp_exit(l);
sau = sadata_upcall_alloc(1);
sau->sau_arg = NULL;
if (p->p_flag & P_WEXIT) {
sadata_upcall_free(sau);
lwp_exit(l);
}
PHOLD(l2);
KDASSERT(sast != NULL);
DPRINTFN(9,("sa_unblock_userret(%d.%d) using stack %p\n",
l->l_proc->p_pid, l->l_lid, sast->sast_stack.ss_sp));
/*
* Defer saving the event lwp's state because a
* PREEMPT upcall could be on the queue already.
*/
if (sa_upcall0(l, SA_UPCALL_UNBLOCKED | SA_UPCALL_DEFER_EVENT,
l, l2, 0, NULL, sau) != 0) {
/*
* We were supposed to deliver an UNBLOCKED
* upcall, but don't have resources to do so.
*/
#ifdef DIAGNOSTIC
printf("sa_unblock_userret: out of upcall resources"
" for %d.%d\n", p->p_pid, l->l_lid);
#endif
sigexit(l, SIGABRT);
/* NOTREACHED */
}
sau->sau_stack = sast->sast_stack;
SCHED_LOCK(s);
SIMPLEQ_INSERT_TAIL(&sa->sa_upcalls, sau, sau_next);
l->l_flag |= L_SA_UPCALL;
l->l_flag &= ~L_SA_BLOCKING;
sa_putcachelwp(p, l2);
}
SCHED_UNLOCK(s);
SA_LWP_STATE_UNLOCK(l, f);
KERNEL_PROC_UNLOCK(l);
}
void
sa_upcall_userret(struct lwp *l)
{
struct lwp *l2;
struct proc *p;
struct sadata *sa;
struct sadata_upcall *sau;
struct sastack *sast;
int f, s;
p = l->l_proc;
sa = p->p_sa;
SCHED_ASSERT_UNLOCKED();
KERNEL_PROC_LOCK(l);
SA_LWP_STATE_LOCK(l, f);
DPRINTFN(7,("sa_upcall_userret(%d.%d %x) \n", p->p_pid, l->l_lid,
l->l_flag));
KDASSERT((l->l_flag & L_SA_BLOCKING) == 0);
sast = NULL;
if (SIMPLEQ_EMPTY(&sa->sa_upcalls) && sa->sa_wokenq_head != NULL)
sast = sa_getstack(sa);
SCHED_LOCK(s);
if (SIMPLEQ_EMPTY(&sa->sa_upcalls) && sa->sa_wokenq_head != NULL &&
sast != NULL) {
/* Invoke an "unblocked" upcall */
l2 = sa->sa_wokenq_head;
sa->sa_wokenq_head = l2->l_forw;
DPRINTFN(9,("sa_upcall_userret(%d.%d) using stack %p\n",
l->l_proc->p_pid, l->l_lid, sast->sast_stack.ss_sp));
SCHED_UNLOCK(s);
if (p->p_flag & P_WEXIT)
lwp_exit(l);
DPRINTFN(8,("sa_upcall_userret(%d.%d) unblocking %d\n",
p->p_pid, l->l_lid, l2->l_lid));
sau = sadata_upcall_alloc(1);
sau->sau_arg = NULL;
if (p->p_flag & P_WEXIT) {
sadata_upcall_free(sau);
lwp_exit(l);
}
if (sa_upcall0(l, SA_UPCALL_UNBLOCKED, l2, l, 0, NULL,
sau) != 0) {
/*
* We were supposed to deliver an UNBLOCKED
* upcall, but don't have resources to do so.
*/
#ifdef DIAGNOSTIC
printf("sa_upcall_userret: out of upcall resources"
" for %d.%d\n", p->p_pid, l->l_lid);
#endif
sigexit(l, SIGABRT);
/* NOTREACHED */
}
sau->sau_stack = sast->sast_stack;
SIMPLEQ_INSERT_TAIL(&sa->sa_upcalls, sau, sau_next);
l2->l_flag &= ~(L_SA_BLOCKING|L_SA_WOKEN);
SCHED_LOCK(s);
sa_putcachelwp(p, l2); /* PHOLD from sa_setwoken */
SCHED_UNLOCK(s);
} else {
SCHED_UNLOCK(s);
if (sast)
sa_setstackfree(sast, sa);
}
KDASSERT(sa->sa_vp == l);
while (!SIMPLEQ_EMPTY(&sa->sa_upcalls))
sa_makeupcalls(l);
if (sa->sa_wokenq_head == NULL)
l->l_flag &= ~L_SA_UPCALL;
SA_LWP_STATE_UNLOCK(l, f);
KERNEL_PROC_UNLOCK(l);
return;
}
static __inline void
sa_makeupcalls(struct lwp *l)
{
struct lwp *l2, *eventq;
struct proc *p;
struct sadata *sa;
struct sa_t **sapp, *sap;
struct sa_t self_sa;
struct sa_t *sas[3], *sasp;
struct sadata_upcall *sau;
union sau_state e_ss;
void *stack, *ap;
ucontext_t u, *up;
int i, nint, nevents, s, type;
p = l->l_proc;
sa = p->p_sa;
sau = SIMPLEQ_FIRST(&sa->sa_upcalls);
SIMPLEQ_REMOVE_HEAD(&sa->sa_upcalls, sau_next);
if (sau->sau_flags & SAU_FLAG_DEFERRED_EVENT)
sa_upcall_getstate(&sau->sau_event,
sau->sau_event.ss_deferred.ss_lwp);
if (sau->sau_flags & SAU_FLAG_DEFERRED_INTERRUPTED)
sa_upcall_getstate(&sau->sau_interrupted,
sau->sau_interrupted.ss_deferred.ss_lwp);
stack = (void *)
(((uintptr_t)sau->sau_stack.ss_sp + sau->sau_stack.ss_size)
& ~ALIGNBYTES);
self_sa.sa_id = l->l_lid;
self_sa.sa_cpu = 0; /* XXX l->l_cpu; */
sas[0] = &self_sa;
nevents = 0;
nint = 0;
if (sau->sau_event.ss_captured.ss_sa.sa_context != NULL) {
if (copyout(&sau->sau_event.ss_captured.ss_ctx,
sau->sau_event.ss_captured.ss_sa.sa_context,
sizeof(ucontext_t)) != 0) {
#ifdef DIAGNOSTIC
printf("sa_makeupcalls(%d.%d): couldn't copyout"
" context of event LWP %d\n",
p->p_pid, l->l_lid, sau->sau_event.ss_captured.ss_sa.sa_id);
#endif
sigexit(l, SIGILL);
/* NOTREACHED */
}
sas[1] = &sau->sau_event.ss_captured.ss_sa;
nevents = 1;
}
if (sau->sau_interrupted.ss_captured.ss_sa.sa_context != NULL) {
KDASSERT(sau->sau_interrupted.ss_captured.ss_sa.sa_context !=
sau->sau_event.ss_captured.ss_sa.sa_context);
if (copyout(&sau->sau_interrupted.ss_captured.ss_ctx,
sau->sau_interrupted.ss_captured.ss_sa.sa_context,
sizeof(ucontext_t)) != 0) {
#ifdef DIAGNOSTIC
printf("sa_makeupcalls(%d.%d): couldn't copyout"
" context of interrupted LWP %d\n",
p->p_pid, l->l_lid, sau->sau_interrupted.ss_captured.ss_sa.sa_id);
#endif
sigexit(l, SIGILL);
/* NOTREACHED */
}
sas[2] = &sau->sau_interrupted.ss_captured.ss_sa;
nint = 1;
}
eventq = NULL;
if (sau->sau_type == SA_UPCALL_UNBLOCKED) {
SCHED_LOCK(s);
eventq = sa->sa_wokenq_head;
sa->sa_wokenq_head = NULL;
SCHED_UNLOCK(s);
l2 = eventq;
while (l2 != NULL) {
nevents++;
l2 = l2->l_forw;
}
}
/* Copy out the activation's ucontext */
u.uc_stack = sau->sau_stack;
u.uc_flags = _UC_STACK;
up = stack;
up--;
if (copyout(&u, up, sizeof(ucontext_t)) != 0) {
sadata_upcall_free(sau);
#ifdef DIAGNOSTIC
printf("sa_makeupcalls: couldn't copyout activation"
" ucontext for %d.%d\n", l->l_proc->p_pid, l->l_lid);
#endif
sigexit(l, SIGILL);
/* NOTREACHED */
}
sas[0]->sa_context = up;
/* Next, copy out the sa_t's and pointers to them. */
sap = (struct sa_t *) up;
sapp = (struct sa_t **) (sap - (1 + nevents + nint));
KDASSERT(nint <= 1);
for (i = nevents + nint; i >= 0; i--) {
sap--;
sapp--;
if (i == 1 + nevents) /* interrupted sa */
sasp = sas[2];
else if (i <= 1) /* self_sa and event sa */
sasp = sas[i];
else { /* extra sas */
KDASSERT(sau->sau_type == SA_UPCALL_UNBLOCKED);
KDASSERT(eventq != NULL);
l2 = eventq;
KDASSERT(l2 != NULL);
eventq = l2->l_forw;
DPRINTFN(8,("sa_makeupcalls(%d.%d) unblocking extra %d\n",
p->p_pid, l->l_lid, l2->l_lid));
sa_upcall_getstate(&e_ss, l2);
SCHED_LOCK(s);
l2->l_flag &= ~(L_SA_BLOCKING|L_SA_WOKEN);
sa_putcachelwp(p, l2); /* PHOLD from sa_setwoken */
SCHED_UNLOCK(s);
if (copyout(&e_ss.ss_captured.ss_ctx,
e_ss.ss_captured.ss_sa.sa_context,
sizeof(ucontext_t)) != 0) {
#ifdef DIAGNOSTIC
printf("sa_makeupcalls(%d.%d): couldn't copyout"
" context of event LWP %d\n",
p->p_pid, l->l_lid, e_ss.ss_captured.ss_sa.sa_id);
#endif
sigexit(l, SIGILL);
/* NOTREACHED */
}
sasp = &e_ss.ss_captured.ss_sa;
}
if ((copyout(sasp, sap, sizeof(struct sa_t)) != 0) ||
(copyout(&sap, sapp, sizeof(struct sa_t *)) != 0)) {
/* Copying onto the stack didn't work. Die. */
sadata_upcall_free(sau);
#ifdef DIAGNOSTIC
printf("sa_makeupcalls: couldn't copyout sa_t "
"%d for %d.%d\n", i, p->p_pid, l->l_lid);
#endif
sigexit(l, SIGILL);
/* NOTREACHED */
}
}
KDASSERT(eventq == NULL);
/* Copy out the arg, if any */
/* xxx assume alignment works out; everything so far has been
* a structure, so...
*/
if (sau->sau_arg) {
ap = (char *)sapp - sau->sau_argsize;
stack = ap;
if (copyout(sau->sau_arg, ap, sau->sau_argsize) != 0) {
/* Copying onto the stack didn't work. Die. */
sadata_upcall_free(sau);
#ifdef DIAGNOSTIC
printf("sa_makeupcalls(%d.%d): couldn't copyout"
" sadata_upcall arg %p size %ld to %p \n",
p->p_pid, l->l_lid,
sau->sau_arg, (long) sau->sau_argsize, ap);
#endif
sigexit(l, SIGILL);
/* NOTREACHED */
}
} else {
ap = 0;
stack = sapp;
}
type = sau->sau_type;
sadata_upcall_free(sau);
DPRINTFN(7,("sa_makeupcalls(%d.%d): type %d\n", p->p_pid,
l->l_lid, type));
cpu_upcall(l, type, nevents, nint, sapp, ap, stack, sa->sa_upcall);
}
static void
sa_setwoken(struct lwp *l)
{
struct lwp *l2, *vp_lwp;
struct proc *p;
struct sadata *sa;
int s;
SCHED_LOCK(s);
if ((l->l_flag & L_SA_BLOCKING) == 0) {
SCHED_UNLOCK(s);
return;
}
p = l->l_proc;
sa = p->p_sa;
vp_lwp = sa->sa_vp;
l2 = NULL;
KDASSERT(vp_lwp != NULL);
DPRINTFN(3,("sa_setwoken(%d.%d) woken, flags %x, vp %d\n",
l->l_proc->p_pid, l->l_lid, l->l_flag,
vp_lwp->l_lid));
if (l->l_flag & L_SA_RECYCLE) {
DPRINTFN(11,("sa_setwoken(%d.%d) recycle\n",
l->l_proc->p_pid, l->l_lid));
l->l_flag &= ~(L_SA_UPCALL|L_SA_BLOCKING|L_SA_RECYCLE);
l->l_flag |= L_SA;
p->p_nrlwps--;
PHOLD(l);
sa_putcachelwp(p, l);
mi_switch(l, NULL);
/* mostly NOTREACHED */
SCHED_ASSERT_UNLOCKED();
splx(s);
KDASSERT(p->p_flag & P_WEXIT);
lwp_exit(l);
}
#if notyet
if (vp_lwp->l_flag & L_SA_IDLE) {
KDASSERT((vp_lwp->l_flag & L_SA_UPCALL) == 0);
KDASSERT(sa->sa_wokenq_head == NULL);
DPRINTFN(3,("sa_setwoken(%d.%d) repossess: idle vp_lwp %d state %d\n",
l->l_proc->p_pid, l->l_lid,
vp_lwp->l_lid, vp_lwp->l_stat));
vp_lwp->l_flag &= ~L_SA_IDLE;
SCHED_UNLOCK(s);
return;
}
#endif
DPRINTFN(3,("sa_setwoken(%d.%d) put on wokenq: vp_lwp %d state %d\n",
l->l_proc->p_pid, l->l_lid, vp_lwp->l_lid,
vp_lwp->l_stat));
PHOLD(l);
if (sa->sa_wokenq_head == NULL)
sa->sa_wokenq_head = l;
else
*sa->sa_wokenq_tailp = l;
*(sa->sa_wokenq_tailp = &l->l_forw) = NULL;
switch (vp_lwp->l_stat) {
case LSONPROC:
if (vp_lwp->l_flag & L_SA_UPCALL)
break;
vp_lwp->l_flag |= L_SA_UPCALL;
if (vp_lwp->l_flag & L_SA_YIELD)
break;
/* XXX IPI vp_lwp->l_cpu */
break;
case LSSLEEP:
if (vp_lwp->l_flag & L_SA_IDLE) {
vp_lwp->l_flag &= ~L_SA_IDLE;
vp_lwp->l_flag |= L_SA_UPCALL;
setrunnable(vp_lwp);
break;
}
vp_lwp->l_flag |= L_SA_UPCALL;
break;
case LSSUSPENDED:
#ifdef DIAGNOSTIC
printf("sa_setwoken(%d.%d) vp lwp %d LSSUSPENDED\n",
l->l_proc->p_pid, l->l_lid, vp_lwp->l_lid);
#endif
break;
case LSSTOP:
vp_lwp->l_flag |= L_SA_UPCALL;
break;
case LSRUN:
if (vp_lwp->l_flag & L_SA_UPCALL)
break;
vp_lwp->l_flag |= L_SA_UPCALL;
if (vp_lwp->l_flag & L_SA_YIELD)
break;
if (vp_lwp->l_slptime > 1) {
void updatepri(struct lwp *);
updatepri(vp_lwp);
}
vp_lwp->l_slptime = 0;
if (vp_lwp->l_flag & L_INMEM) {
if (vp_lwp->l_cpu == curcpu())
l2 = vp_lwp;
else
need_resched(vp_lwp->l_cpu);
} else
sched_wakeup(&proc0);
break;
default:
panic("sa_vp LWP not sleeping/onproc/runnable");
}
if (l->l_flag & L_SA_WOKEN)
sched_wakeup(sa);
else
l->l_flag |= L_SA_WOKEN;
l->l_stat = LSSUSPENDED;
p->p_nrlwps--;
mi_switch(l, l2);
/* maybe NOTREACHED */
SCHED_ASSERT_UNLOCKED();
splx(s);
if (p->p_flag & P_WEXIT)
lwp_exit(l);
}
static struct lwp *
sa_vp_repossess(struct lwp *l)
{
struct lwp *l2;
struct proc *p = l->l_proc;
struct sadata *sa = p->p_sa;
SCHED_ASSERT_LOCKED();
/*
* Put ourselves on the virtual processor and note that the
* previous occupant of that position was interrupted.
*/
l2 = sa->sa_vp;
sa->sa_vp = l;
if (l2->l_flag & L_SA_YIELD)
l2->l_flag &= ~(L_SA_YIELD|L_SA_IDLE);
DPRINTFN(1,("sa_vp_repossess(%d.%d) vp lwp %d state %d\n",
p->p_pid, l->l_lid, l2->l_lid, l2->l_stat));
KDASSERT(l2 != l);
if (l2) {
switch (l2->l_stat) {
case LSRUN:
remrunqueue(l2);
p->p_nrlwps--;
break;
case LSSLEEP:
unsleep(l2);
l2->l_flag &= ~L_SINTR;
break;
case LSSUSPENDED:
#ifdef DIAGNOSTIC
printf("sa_vp_repossess(%d.%d) vp lwp %d LSSUSPENDED\n",
l->l_proc->p_pid, l->l_lid, l2->l_lid);
#endif
break;
#ifdef DIAGNOSTIC
default:
panic("SA VP %d.%d is in state %d, not running"
" or sleeping\n", p->p_pid, l2->l_lid,
l2->l_stat);
#endif
}
l2->l_stat = LSSUSPENDED;
}
return l2;
}
#ifdef DEBUG
int debug_print_sa(struct proc *);
int debug_print_lwp(struct lwp *);
int debug_print_proc(int);
int
debug_print_proc(int pid)
{
struct proc *p;
p = pfind(pid);
if (p == NULL)
printf("No process %d\n", pid);
else
debug_print_sa(p);
return 0;
}
int
debug_print_sa(struct proc *p)
{
struct lwp *l;
struct sadata *sa;
printf("Process %d (%s), state %d, address %p, flags %x\n",
p->p_pid, p->p_comm, p->p_stat, p, p->p_flag);
printf("LWPs: %d (%d running, %d zombies)\n",
p->p_nlwps, p->p_nrlwps, p->p_nzlwps);
LIST_FOREACH(l, &p->p_lwps, l_sibling)
debug_print_lwp(l);
sa = p->p_sa;
if (sa) {
if (sa->sa_vp)
printf("SA VP: %d %s\n", sa->sa_vp->l_lid,
sa->sa_vp->l_flag & L_SA_YIELD ?
(sa->sa_vp->l_flag & L_SA_IDLE ?
"idle" : "yielding") : "");
printf("SAs: %d cached LWPs\n", sa->sa_ncached);
LIST_FOREACH(l, &sa->sa_lwpcache, l_sibling)
debug_print_lwp(l);
}
return 0;
}
int
debug_print_lwp(struct lwp *l)
{
printf("LWP %d address %p ", l->l_lid, l);
printf("state %d flags %x ", l->l_stat, l->l_flag);
if (l->l_wchan)
printf("wait %p %s", l->l_wchan, l->l_wmesg);
printf("\n");
return 0;
}
#endif