#include <kern/assert.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/user.h>
#include <sys/resourcevar.h>
#include <sys/vnode_internal.h>
#include <sys/file_internal.h>
#include <sys/acct.h>
#if KTRACE
#include <sys/ktrace.h>
#endif
#include <bsm/audit_kernel.h>
#include <mach/mach_types.h>
#include <kern/kern_types.h>
#include <kern/kalloc.h>
#include <kern/mach_param.h>
#include <kern/task.h>
#include <kern/zalloc.h>
#include <machine/spl.h>
#include <vm/vm_protos.h> // for vm_map_commpage64
thread_t cloneproc(struct proc *, int);
struct proc * forkproc(struct proc *, int);
thread_t procdup(struct proc *child, struct proc *parent);
#define DOFORK 0x1
#define DOVFORK 0x2
static int fork1(struct proc *, long, register_t *);
int
fork(struct proc *p, __unused void *uap, register_t *retval)
{
return (fork1(p, (long)DOFORK, retval));
}
int
vfork(struct proc *p, void *uap, register_t *retval)
{
register struct proc * newproc;
register uid_t uid;
thread_t cur_act = (thread_t)current_thread();
int count;
task_t t;
uthread_t ut;
uid = kauth_cred_get()->cr_ruid;
if ((nprocs >= maxproc - 1 && uid != 0) || nprocs >= maxproc) {
tablefull("proc");
retval[1] = 0;
return (EAGAIN);
}
count = chgproccnt(uid, 1);
if (uid != 0 && count > p->p_rlimit[RLIMIT_NPROC].rlim_cur) {
(void)chgproccnt(uid, -1);
return (EAGAIN);
}
ut = (struct uthread *)get_bsdthread_info(cur_act);
if (ut->uu_flag & UT_VFORK) {
printf("vfork called recursively by %s\n", p->p_comm);
(void)chgproccnt(uid, -1);
return (EINVAL);
}
p->p_flag |= P_VFORK;
p->p_vforkcnt++;
newproc = (struct proc *)forkproc(p,1);
AUDIT_ARG(pid, newproc->p_pid);
LIST_INSERT_AFTER(p, newproc, p_pglist);
newproc->p_pptr = p;
newproc->task = p->task;
LIST_INSERT_HEAD(&p->p_children, newproc, p_sibling);
LIST_INIT(&newproc->p_children);
LIST_INSERT_HEAD(&allproc, newproc, p_list);
LIST_INSERT_HEAD(PIDHASH(newproc->p_pid), newproc, p_hash);
TAILQ_INIT(& newproc->p_evlist);
newproc->p_stat = SRUN;
newproc->p_flag |= P_INVFORK;
newproc->p_vforkact = cur_act;
ut->uu_flag |= UT_VFORK;
ut->uu_proc = newproc;
ut->uu_userstate = (void *)act_thread_csave();
ut->uu_vforkmask = ut->uu_sigmask;
if (ut->uu_flag & UT_SETUID) {
ut->uu_flag |= UT_WASSETUID;
ut->uu_flag &= ~UT_SETUID;
}
thread_set_child(cur_act, newproc->p_pid);
microtime(&newproc->p_stats->p_start);
newproc->p_acflag = AFORK;
newproc->p_flag |= P_PPWAIT;
signal_unlock(newproc);
retval[0] = newproc->p_pid;
retval[1] = 1;
return (0);
}
void
vfork_return(__unused thread_t th_act, struct proc *p, struct proc *p2,
register_t *retval)
{
thread_t cur_act = (thread_t)current_thread();
uthread_t ut;
ut = (struct uthread *)get_bsdthread_info(cur_act);
act_thread_catt(ut->uu_userstate);
p->p_vforkcnt--;
if (p->p_vforkcnt <0)
panic("vfork cnt is -ve");
if (p->p_vforkcnt <=0)
p->p_flag &= ~P_VFORK;
ut->uu_userstate = 0;
ut->uu_flag &= ~UT_VFORK;
if (ut->uu_flag & UT_WASSETUID) {
ut->uu_flag |= UT_SETUID;
ut->uu_flag &= UT_WASSETUID;
}
ut->uu_proc = 0;
ut->uu_sigmask = ut->uu_vforkmask;
p2->p_flag &= ~P_INVFORK;
p2->p_vforkact = (void *)0;
thread_set_parent(cur_act, p2->p_pid);
if (retval) {
retval[0] = p2->p_pid;
retval[1] = 0;
}
return;
}
thread_t
procdup(struct proc *child, struct proc *parent)
{
thread_t thread;
task_t task;
kern_return_t result;
if (parent->task == kernel_task)
result = task_create_internal(TASK_NULL, FALSE, &task);
else
result = task_create_internal(parent->task, TRUE, &task);
if (result != KERN_SUCCESS)
printf("fork/procdup: task_create failed. Code: 0x%x\n", result);
child->task = task;
set_bsdtask_info(task, child);
if (parent->p_flag & P_LP64) {
task_set_64bit(task, TRUE);
child->p_flag |= P_LP64;
#ifdef __PPC__
pmap_map_sharedpage(task, get_map_pmap(get_task_map(task)));
vm_map_commpage64(get_task_map(task));
#endif
} else {
task_set_64bit(task, FALSE);
child->p_flag &= ~P_LP64;
}
if (child->p_nice != 0)
resetpriority(child);
result = thread_create(task, &thread);
if (result != KERN_SUCCESS)
printf("fork/procdup: thread_create failed. Code: 0x%x\n", result);
return(thread);
}
static int
fork1(p1, flags, retval)
struct proc *p1;
long flags;
register_t *retval;
{
register struct proc *p2;
register uid_t uid;
thread_t newth;
int count;
task_t t;
uid = kauth_cred_get()->cr_ruid;
if ((nprocs >= maxproc - 1 && uid != 0) || nprocs >= maxproc) {
tablefull("proc");
retval[1] = 0;
return (EAGAIN);
}
count = chgproccnt(uid, 1);
if (uid != 0 && count > p1->p_rlimit[RLIMIT_NPROC].rlim_cur) {
(void)chgproccnt(uid, -1);
return (EAGAIN);
}
newth = cloneproc(p1, 1);
thread_dup(newth);
p2 = (struct proc *)(get_bsdtask_info(get_threadtask(newth)));
set_security_token(p2);
AUDIT_ARG(pid, p2->p_pid);
thread_set_child(newth, p2->p_pid);
microtime(&p2->p_stats->p_start);
p2->p_acflag = AFORK;
if (flags == DOVFORK)
p2->p_flag |= P_PPWAIT;
signal_unlock(p2);
(void) thread_resume(newth);
if ((t = (task_t)get_threadtask(newth)) != NULL) {
task_deallocate(t);
}
thread_deallocate(newth);
KNOTE(&p1->p_klist, NOTE_FORK | p2->p_pid);
while (p2->p_flag & P_PPWAIT)
tsleep(p1, PWAIT, "ppwait", 0);
retval[0] = p2->p_pid;
retval[1] = 0;
return (0);
}
thread_t
cloneproc(p1, lock)
register struct proc *p1;
register int lock;
{
register struct proc *p2;
thread_t th;
p2 = (struct proc *)forkproc(p1,lock);
th = procdup(p2, p1);
LIST_INSERT_AFTER(p1, p2, p_pglist);
p2->p_pptr = p1;
LIST_INSERT_HEAD(&p1->p_children, p2, p_sibling);
LIST_INIT(&p2->p_children);
LIST_INSERT_HEAD(&allproc, p2, p_list);
LIST_INSERT_HEAD(PIDHASH(p2->p_pid), p2, p_hash);
TAILQ_INIT(&p2->p_evlist);
p2->p_stat = SRUN;
return(th);
}
struct proc *
forkproc(p1, lock)
register struct proc *p1;
register int lock;
{
register struct proc *p2, *newproc;
static int nextpid = 0, pidchecked = 0;
MALLOC_ZONE(newproc, struct proc *,
sizeof *newproc, M_PROC, M_WAITOK);
if (newproc == NULL)
panic("forkproc: M_PROC zone exhausted");
MALLOC_ZONE(newproc->p_stats, struct pstats *,
sizeof *newproc->p_stats, M_SUBPROC, M_WAITOK);
if (newproc->p_stats == NULL)
panic("forkproc: M_SUBPROC zone exhausted (p_stats)");
MALLOC_ZONE(newproc->p_sigacts, struct sigacts *,
sizeof *newproc->p_sigacts, M_SUBPROC, M_WAITOK);
if (newproc->p_sigacts == NULL)
panic("forkproc: M_SUBPROC zone exhausted (p_sigacts)");
nextpid++;
retry:
if (nextpid >= PID_MAX) {
nextpid = 100;
pidchecked = 0;
}
if (nextpid >= pidchecked) {
int doingzomb = 0;
pidchecked = PID_MAX;
p2 = allproc.lh_first;
again:
for (; p2 != 0; p2 = p2->p_list.le_next) {
while (p2->p_pid == nextpid ||
p2->p_pgrp->pg_id == nextpid ||
p2->p_session->s_sid == nextpid) {
nextpid++;
if (nextpid >= pidchecked)
goto retry;
}
if (p2->p_pid > nextpid && pidchecked > p2->p_pid)
pidchecked = p2->p_pid;
if (p2->p_pgrp && p2->p_pgrp->pg_id > nextpid &&
pidchecked > p2->p_pgrp->pg_id)
pidchecked = p2->p_pgrp->pg_id;
if (p2->p_session->s_sid > nextpid &&
pidchecked > p2->p_session->s_sid)
pidchecked = p2->p_session->s_sid;
}
if (!doingzomb) {
doingzomb = 1;
p2 = zombproc.lh_first;
goto again;
}
}
nprocs++;
p2 = newproc;
p2->p_stat = SIDL;
p2->p_shutdownstate = 0;
p2->p_pid = nextpid;
bzero(&p2->p_startzero,
(unsigned) ((caddr_t)&p2->p_endzero - (caddr_t)&p2->p_startzero));
bcopy(&p1->p_startcopy, &p2->p_startcopy,
(unsigned) ((caddr_t)&p2->p_endcopy - (caddr_t)&p2->p_startcopy));
p2->vm_shm = (void *)NULL;
p2->p_flag = (p1->p_flag & (P_LP64 | P_CLASSIC | P_AFFINITY));
if (p1->p_flag & P_PROFIL)
startprofclock(p2);
p2->p_ucred = kauth_cred_get_with_ref();
lck_mtx_init(&p2->p_mlock, proc_lck_grp, proc_lck_attr);
lck_mtx_init(&p2->p_fdmlock, proc_lck_grp, proc_lck_attr);
klist_init(&p2->p_klist);
p2->p_textvp = p1->p_textvp;
if (p2->p_textvp) {
vnode_rele(p2->p_textvp);
}
p2->p_fd = fdcopy(p1);
if (p1->vm_shm) {
(void)shmfork(p1,p2);
}
if (p1->p_limit->p_lflags & PL_SHAREMOD)
p2->p_limit = limcopy(p1->p_limit);
else {
p2->p_limit = p1->p_limit;
p2->p_limit->p_refcnt++;
}
bzero(&p2->p_stats->pstat_startzero,
(unsigned) ((caddr_t)&p2->p_stats->pstat_endzero -
(caddr_t)&p2->p_stats->pstat_startzero));
bcopy(&p1->p_stats->pstat_startcopy, &p2->p_stats->pstat_startcopy,
((caddr_t)&p2->p_stats->pstat_endcopy -
(caddr_t)&p2->p_stats->pstat_startcopy));
bzero(&p2->p_stats->user_p_prof, sizeof(struct user_uprof));
if (p1->p_sigacts != NULL)
(void)memcpy(p2->p_sigacts,
p1->p_sigacts, sizeof *p2->p_sigacts);
else
(void)memset(p2->p_sigacts, 0, sizeof *p2->p_sigacts);
if (p1->p_session->s_ttyvp != NULL && p1->p_flag & P_CONTROLT)
p2->p_flag |= P_CONTROLT;
p2->p_argslen = p1->p_argslen;
p2->p_argc = p1->p_argc;
p2->p_xstat = 0;
p2->p_ru = NULL;
p2->p_debugger = 0;
lockinit(&p2->signal_lock, PVM, "signal", 0, 0);
if (lock)
signal_lock(p2);
p2->sigwait = FALSE;
p2->sigwait_thread = NULL;
p2->exit_thread = NULL;
p2->user_stack = p1->user_stack;
p2->p_vforkcnt = 0;
p2->p_vforkact = 0;
p2->p_lflag = 0;
p2->p_ladvflag = 0;
p2->p_internalref = 0;
TAILQ_INIT(&p2->p_uthlist);
TAILQ_INIT(&p2->aio_activeq);
TAILQ_INIT(&p2->aio_doneq);
p2->aio_active_count = 0;
p2->aio_done_count = 0;
#if KTRACE
if (p1->p_traceflag&KTRFAC_INHERIT) {
p2->p_traceflag = p1->p_traceflag;
if ((p2->p_tracep = p1->p_tracep) != NULL) {
vnode_ref(p2->p_tracep);
}
}
#endif
return(p2);
}
void
proc_lock(proc_t p)
{
lck_mtx_lock(&p->p_mlock);
}
void
proc_unlock(proc_t p)
{
lck_mtx_unlock(&p->p_mlock);
}
#include <kern/zalloc.h>
struct zone *uthread_zone;
int uthread_zone_inited = 0;
void
uthread_zone_init(void)
{
if (!uthread_zone_inited) {
uthread_zone = zinit(sizeof(struct uthread),
THREAD_MAX * sizeof(struct uthread),
THREAD_CHUNK * sizeof(struct uthread),
"uthreads");
uthread_zone_inited = 1;
}
}
void *
uthread_alloc(task_t task, thread_t thr_act )
{
struct proc *p;
struct uthread *uth, *uth_parent;
void *ut;
boolean_t funnel_state;
if (!uthread_zone_inited)
uthread_zone_init();
ut = (void *)zalloc(uthread_zone);
bzero(ut, sizeof(struct uthread));
p = (struct proc *) get_bsdtask_info(task);
uth = (struct uthread *)ut;
uth_parent = (struct uthread *)get_bsdthread_info(current_thread());
if ((task == current_task()) &&
(uth_parent != NULL) &&
(uth_parent->uu_ucred != NOCRED)) {
uth->uu_ucred = uth_parent->uu_ucred;
kauth_cred_ref(uth->uu_ucred);
if (uth_parent->uu_flag & UT_SETUID)
uth->uu_flag |= UT_SETUID;
} else {
uth->uu_ucred = NOCRED;
}
if (task != kernel_task) {
funnel_state = thread_funnel_set(kernel_flock, TRUE);
if (uth_parent) {
if (uth_parent->uu_flag & UT_SAS_OLDMASK)
uth->uu_sigmask = uth_parent->uu_oldmask;
else
uth->uu_sigmask = uth_parent->uu_sigmask;
}
uth->uu_act = thr_act;
if (p) {
TAILQ_INSERT_TAIL(&p->p_uthlist, uth, uu_list);
}
(void)thread_funnel_set(kernel_flock, funnel_state);
}
return (ut);
}
void
uthread_free(task_t task, void *uthread, void * bsd_info)
{
struct _select *sel;
struct uthread *uth = (struct uthread *)uthread;
struct proc * p = (struct proc *)bsd_info;
boolean_t funnel_state;
assert(uth->uu_ar == NULL);
sel = &uth->uu_select;
if (sel->nbytes) {
FREE(sel->ibits, M_TEMP);
FREE(sel->obits, M_TEMP);
}
if (sel->allocsize && sel->wqset){
kfree(sel->wqset, sel->allocsize);
sel->count = 0;
sel->allocsize = 0;
sel->wqset = 0;
sel->wql = 0;
}
if (uth->uu_ucred != NOCRED)
kauth_cred_rele(uth->uu_ucred);
if ((task != kernel_task) && p) {
funnel_state = thread_funnel_set(kernel_flock, TRUE);
TAILQ_REMOVE(&p->p_uthlist, uth, uu_list);
(void)thread_funnel_set(kernel_flock, funnel_state);
}
zfree(uthread_zone, uthread);
}