int do_fork(int clone_flags,
struct frame *frame,
struct task_struct **store)
{
int retval;
struct task_struct *task;
retval = -ENOMEM;
task = alloc_task();
if (!task) {
goto out_fork;
}
INIT_LIST_HEAD(&task->list);
INIT_LIST_HEAD(&task->wait_list);
RBTREE_NODE_INIT(&task->sched_entry);
retval = do_copy_mm(clone_flags,task);
if(retval < 0) {
goto bad_fork_cleanup_mm;
}
retval = do_copy_kern_stack(frame,task);
if(retval < 0) {
goto bad_fork_cleanup_mm;
}
task->trapframe = frame;
task->ppid = curtask->pid;
task->task_status = TASK_RUNNING;
task->task_type = TASK_TYPE_USER;
task->timeslice = 10;
task->prio = 1;
*store = task;
task_pidmap[task->pid] = task;
return 0;
bad_fork_cleanup_mm:
exit_mm(task);
bad_fork_free:
free_task(task);
out_fork:
return retval;
}
void daemonize(void)
{
struct fs_struct *fs;
/*
* If we were started as result of loading a module, close all of the
* user space pages. We don't need them, and if we didn't close them
* they would be locked into memory.
*/
exit_mm(current);
current->session = 1;
current->pgrp = 1;
current->tty = NULL;
/* Become as one with the init task */
exit_fs(current); /* current->fs->count--; */
fs = init_task.fs;
current->fs = fs;
atomic_inc(&fs->count);
exit_files(current);
current->files = init_task.files;
atomic_inc(¤t->files->count);
}
/* main function of the polling thread
*/
static int lirc_thread(void *irctl)
{
struct irctl *ir = irctl;
lock_kernel();
/* This thread doesn't need any user-level access,
* so get rid of all our resources
*/
exit_mm(current);
exit_files(current);
exit_fs(current);
current->session = 1;
current->pgrp = 1;
current->euid = 0;
current->tty = NULL;
sigfillset(¤t->blocked);
strcpy(current->comm, "lirc_dev");
unlock_kernel();
if (ir->t_notify != NULL) {
up(ir->t_notify);
}
dprintk(LOGHEAD "poll thread started\n", ir->p.name, ir->p.minor);
do {
if (ir->open) {
if (ir->jiffies_to_wait) {
current->state = TASK_INTERRUPTIBLE;
schedule_timeout(ir->jiffies_to_wait);
} else {
interruptible_sleep_on(ir->p.get_queue(ir->p.data));
}
if (signal_pending(current)) {
break;
}
if (!add_to_buf(ir)) {
wake_up_interruptible(&ir->wait_poll);
}
} else {
/* if device not opened so we can sleep half a second */
current->state = TASK_INTERRUPTIBLE;
schedule_timeout(HZ/2);
}
} while (!ir->shutdown && !signal_pending(current));
ir->tpid = -1;
if (ir->t_notify != NULL) {
up(ir->t_notify);
}
dprintk(LOGHEAD "poll thread ended\n", ir->p.name, ir->p.minor);
return 0;
}
static void daemonize_keep_fs(void)
{
int fd;
exit_mm(current);
set_special_pids(1, 1);
current->tty = NULL;
for (fd = 0; fd < 255; fd++)
close(fd);
}
int exit(struct task_struct *task)
{
assert(task);
if (task == curtask)
lcr3(pgd2p(kpgd));
schedule_delete_task(task);
exit_notify(task);
exit_mm(task->mm);
exit_files(task);
exit_task(task);
if (task == curtask) {
curtask = NULL;
schedule();
}
return 0;
}
/*
* Start up an nfsiod process. This is an awful hack, because when running
* as a module, we will keep insmod's memory. Besides, the current->comm
* hack won't work in this case
* The best would be to have a syscall for nfs client control that (among
* other things) forks biod's.
* Alternatively, we might want to have the idle task spawn biod's on demand.
*/
static int run_nfsiod(void *dummy)
{
int ret;
#ifdef __SMP__
lock_kernel();
syscall_count++;
#endif
MOD_INC_USE_COUNT;
exit_mm(current);
current->session = 1;
current->pgrp = 1;
sprintf(current->comm, "nfsiod");
#ifndef MODULE
current->blocked = ~0UL;
#endif
ret = nfsiod();
MOD_DEC_USE_COUNT;
return ret;
}
/*
* This creates a new process as a copy of the old one,
* but does not actually start it yet.
*
* It copies the registers, and all the appropriate
* parts of the process environment (as per the clone
* flags). The actual kick-off is left to the caller.
*/
struct task_struct *copy_process(unsigned long clone_flags,
unsigned long stack_start,
struct pt_regs *regs,
unsigned long stack_size,
int __user *parent_tidptr,
int __user *child_tidptr)
{
int retval;
struct task_struct *p = NULL;
if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
return ERR_PTR(-EINVAL);
/*
* Thread groups must share signals as well, and detached threads
* can only be started up within the thread group.
*/
if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
return ERR_PTR(-EINVAL);
/*
* Shared signal handlers imply shared VM. By way of the above,
* thread groups also imply shared VM. Blocking this case allows
* for various simplifications in other code.
*/
if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
return ERR_PTR(-EINVAL);
retval = security_task_create(clone_flags);
if (retval)
goto fork_out;
retval = -ENOMEM;
p = dup_task_struct(current);
if (!p)
goto fork_out;
retval = -EAGAIN;
if (atomic_read(&p->user->processes) >=
p->rlim[RLIMIT_NPROC].rlim_cur) {
if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
p->user != &root_user)
goto bad_fork_free;
}
atomic_inc(&p->user->__count);
atomic_inc(&p->user->processes);
get_group_info(p->group_info);
/*
* If multiple threads are within copy_process(), then this check
* triggers too late. This doesn't hurt, the check is only there
* to stop root fork bombs.
*/
if (nr_threads >= max_threads)
goto bad_fork_cleanup_count;
if (!try_module_get(p->thread_info->exec_domain->module))
goto bad_fork_cleanup_count;
if (p->binfmt && !try_module_get(p->binfmt->module))
goto bad_fork_cleanup_put_domain;
p->did_exec = 0;
copy_flags(clone_flags, p);
if (clone_flags & CLONE_IDLETASK)
p->pid = 0;
else {
p->pid = alloc_pidmap();
if (p->pid == -1)
goto bad_fork_cleanup;
}
retval = -EFAULT;
if (clone_flags & CLONE_PARENT_SETTID)
if (put_user(p->pid, parent_tidptr))
goto bad_fork_cleanup;
p->proc_dentry = NULL;
INIT_LIST_HEAD(&p->children);
INIT_LIST_HEAD(&p->sibling);
init_waitqueue_head(&p->wait_chldexit);
p->vfork_done = NULL;
spin_lock_init(&p->alloc_lock);
spin_lock_init(&p->proc_lock);
clear_tsk_thread_flag(p, TIF_SIGPENDING);
init_sigpending(&p->pending);
p->it_real_value = p->it_virt_value = p->it_prof_value = 0;
p->it_real_incr = p->it_virt_incr = p->it_prof_incr = 0;
init_timer(&p->real_timer);
p->real_timer.data = (unsigned long) p;
p->utime = p->stime = 0;
p->cutime = p->cstime = 0;
p->lock_depth = -1; /* -1 = no lock */
p->start_time = get_jiffies_64();
p->security = NULL;
p->io_context = NULL;
p->audit_context = NULL;
#ifdef CONFIG_NUMA
p->mempolicy = mpol_copy(p->mempolicy);
if (IS_ERR(p->mempolicy)) {
retval = PTR_ERR(p->mempolicy);
p->mempolicy = NULL;
goto bad_fork_cleanup;
}
#endif
retval = -ENOMEM;
if ((retval = security_task_alloc(p)))
goto bad_fork_cleanup_policy;
if ((retval = audit_alloc(p)))
goto bad_fork_cleanup_security;
/* copy all the process information */
if ((retval = copy_semundo(clone_flags, p)))
goto bad_fork_cleanup_audit;
if ((retval = copy_files(clone_flags, p)))
goto bad_fork_cleanup_semundo;
if ((retval = copy_fs(clone_flags, p)))
goto bad_fork_cleanup_files;
if ((retval = copy_sighand(clone_flags, p)))
goto bad_fork_cleanup_fs;
if ((retval = copy_signal(clone_flags, p)))
goto bad_fork_cleanup_sighand;
if ((retval = copy_mm(clone_flags, p)))
goto bad_fork_cleanup_signal;
if ((retval = copy_namespace(clone_flags, p)))
goto bad_fork_cleanup_mm;
retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
if (retval)
goto bad_fork_cleanup_namespace;
p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
/*
* Clear TID on mm_release()?
*/
p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL;
/*
* Syscall tracing should be turned off in the child regardless
* of CLONE_PTRACE.
*/
clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);
/* Our parent execution domain becomes current domain
These must match for thread signalling to apply */
p->parent_exec_id = p->self_exec_id;
/* ok, now we should be set up.. */
p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
p->pdeath_signal = 0;
/* Perform scheduler related setup */
sched_fork(p);
/*
* Ok, make it visible to the rest of the system.
* We dont wake it up yet.
*/
p->tgid = p->pid;
p->group_leader = p;
INIT_LIST_HEAD(&p->ptrace_children);
INIT_LIST_HEAD(&p->ptrace_list);
/* Need tasklist lock for parent etc handling! */
write_lock_irq(&tasklist_lock);
/*
* Check for pending SIGKILL! The new thread should not be allowed
* to slip out of an OOM kill. (or normal SIGKILL.)
*/
if (sigismember(¤t->pending.signal, SIGKILL)) {
write_unlock_irq(&tasklist_lock);
retval = -EINTR;
goto bad_fork_cleanup_namespace;
}
/* CLONE_PARENT re-uses the old parent */
if (clone_flags & CLONE_PARENT)
p->real_parent = current->real_parent;
else
p->real_parent = current;
p->parent = p->real_parent;
if (clone_flags & CLONE_THREAD) {
spin_lock(¤t->sighand->siglock);
/*
* Important: if an exit-all has been started then
* do not create this new thread - the whole thread
* group is supposed to exit anyway.
*/
if (current->signal->group_exit) {
spin_unlock(¤t->sighand->siglock);
write_unlock_irq(&tasklist_lock);
retval = -EAGAIN;
goto bad_fork_cleanup_namespace;
}
p->tgid = current->tgid;
p->group_leader = current->group_leader;
if (current->signal->group_stop_count > 0) {
/*
* There is an all-stop in progress for the group.
* We ourselves will stop as soon as we check signals.
* Make the new thread part of that group stop too.
*/
current->signal->group_stop_count++;
set_tsk_thread_flag(p, TIF_SIGPENDING);
}
spin_unlock(¤t->sighand->siglock);
}
SET_LINKS(p);
if (p->ptrace & PT_PTRACED)
__ptrace_link(p, current->parent);
attach_pid(p, PIDTYPE_PID, p->pid);
if (thread_group_leader(p)) {
attach_pid(p, PIDTYPE_TGID, p->tgid);
attach_pid(p, PIDTYPE_PGID, process_group(p));
attach_pid(p, PIDTYPE_SID, p->signal->session);
if (p->pid)
__get_cpu_var(process_counts)++;
} else
link_pid(p, p->pids + PIDTYPE_TGID, &p->group_leader->pids[PIDTYPE_TGID].pid);
nr_threads++;
write_unlock_irq(&tasklist_lock);
retval = 0;
fork_out:
if (retval)
return ERR_PTR(retval);
return p;
bad_fork_cleanup_namespace:
exit_namespace(p);
bad_fork_cleanup_mm:
exit_mm(p);
if (p->active_mm)
mmdrop(p->active_mm);
bad_fork_cleanup_signal:
exit_signal(p);
bad_fork_cleanup_sighand:
exit_sighand(p);
bad_fork_cleanup_fs:
exit_fs(p); /* blocking */
bad_fork_cleanup_files:
exit_files(p); /* blocking */
bad_fork_cleanup_semundo:
exit_sem(p);
bad_fork_cleanup_audit:
audit_free(p);
bad_fork_cleanup_security:
security_task_free(p);
bad_fork_cleanup_policy:
#ifdef CONFIG_NUMA
mpol_free(p->mempolicy);
#endif
bad_fork_cleanup:
if (p->pid > 0)
free_pidmap(p->pid);
if (p->binfmt)
module_put(p->binfmt->module);
bad_fork_cleanup_put_domain:
module_put(p->thread_info->exec_domain->module);
bad_fork_cleanup_count:
put_group_info(p->group_info);
atomic_dec(&p->user->processes);
free_uid(p->user);
bad_fork_free:
free_task(p);
goto fork_out;
}
int ticker_thread(void *data)
{
struct timer_list ticker;
// detach
lock_kernel();
exit_mm(current);
exit_files(current);
exit_fs(current);
// setsid equivalent, used at start of kernel thread, no error checks needed, or at least none made :).
current->leader = 1;
current->session = current->pgrp = current->pid;
current->tty = NULL;
current->tty_old_pgrp = 0;
// Name this thread
sprintf(current->comm, "usbd-bi");
// setup signal handler
current->exit_signal = SIGCHLD;
spin_lock(¤t->sigmask_lock);
flush_signals(current);
spin_unlock(¤t->sigmask_lock);
// XXX Run at a high priority, ahead of sync and friends
// current->nice = -20;
current->policy = SCHED_OTHER;
unlock_kernel();
// setup timer
init_timer(&ticker);
ticker.data = 0;
ticker.function = ticker_tick;
// let startup continue
up(&ticker_sem_start);
// process loop
for (ticker_timer_set = ticker_terminating = 0; !ticker_terminating;) {
char buf[100];
char *cp;
if (!ticker_timer_set) {
mod_timer(&ticker, jiffies + HZ*RETRYTIME);
}
// wait for someone to tell us to do something
down(&ticker_sem_work);
if (udc_interrupts != udc_interrupts_last) {
dbg_tick(1,"--------------");
}
// do some work
memset(buf, 0, sizeof(buf));
cp = buf;
if (dbgflg_usbdbi_tick) {
unsigned long flags;
local_irq_save(flags);
dbg_tick(1,"[%d]", udc_interrupts);
udc_regs();
local_irq_restore(flags);
}
}
// remove timer
del_timer(&ticker);
// let the process stopping us know we are done and return
up(&ticker_sem_start);
return 0;
}
int ticker_thread (void *data)
{
struct timer_list ticker;
// detach
lock_kernel ();
exit_mm (current);
exit_files (current);
exit_fs (current);
// setsid equivalent, used at start of kernel thread, no error checks needed, or at least none made :).
current->leader = 1;
current->session = current->pgrp = current->pid;
current->tty = NULL;
current->tty_old_pgrp = 0;
// Name this thread
sprintf (current->comm, "usbd-bi");
// setup signal handler
current->exit_signal = SIGCHLD;
spin_lock (¤t->sigmask_lock);
flush_signals (current);
spin_unlock (¤t->sigmask_lock);
// XXX Run at a high priority, ahead of sync and friends
// current->nice = -20;
current->policy = SCHED_OTHER;
unlock_kernel ();
// setup timer
init_timer (&ticker);
ticker.data = 0;
ticker.function = ticker_tick;
// let startup continue
up (&ticker_sem_start);
// process loop
for (ticker_timer_set = ticker_terminating = 0; !ticker_terminating;) {
char buf[100];
char *cp;
if (!ticker_timer_set) {
mod_timer (&ticker, jiffies + HZ * RETRYTIME);
}
// wait for someone to tell us to do something
down (&ticker_sem_work);
if (udc_interrupts != udc_interrupts_last) {
dbg_tick (3, "--------------");
}
// do some work
memset (buf, 0, sizeof (buf));
cp = buf;
if (dbgflg_usbdbi_tick) {
unsigned long flags;
local_irq_save (flags);
dbg_tick (2, "[%d]", udc_interrupts);
udc_regs ();
local_irq_restore (flags);
}
#if 0
// XXX
#if defined(CONFIG_SA1110_CALYPSO) && defined(CONFIG_PM) && defined(CONFIG_USBD_TRAFFIC_KEEPAWAKE)
/* Check for rx/tx activity, and reset the sleep timer if present */
if (device->usbd_rxtx_timestamp != device->usbd_last_rxtx_timestamp) {
extern void resetSleepTimer (void);
dbg_tick (7, "resetting sleep timer");
resetSleepTimer ();
device->usbd_last_rxtx_timestamp = device->usbd_rxtx_timestamp;
}
#endif
#endif
#if 0
/* Check for TX endpoint stall. If the endpoint has
stalled, we have probably run into the DMA/TCP window
problem, and the only thing we can do is disconnect
from the bus, then reconnect (and re-enumerate...). */
if (reconnect > 0 && 0 >= --reconnect) {
dbg_init (0, "TX stall disconnect finished");
udc_connect ();
} else if (0 != USBD_STALL_TIMEOUT_SECONDS) {
// Stall watchdog unleashed
unsigned long now, tx_waiting;
now = jiffies;
tx_waiting = (now - tx_queue_head_timestamp (now)) / HZ;
if (tx_waiting > USBD_STALL_TIMEOUT_SECONDS) {
/* The URB at the head of the queue has waited too long */
reconnect = USBD_STALL_DISCONNECT_DURATION;
dbg_init (0, "TX stalled, disconnecting for %d seconds", reconnect);
udc_disconnect ();
}
}
#endif
}
// remove timer
del_timer (&ticker);
// let the process stopping us know we are done and return
up (&ticker_sem_start);
return 0;
}
/*
* This is the rpciod kernel thread
*/
static int
rpciod(void *ptr)
{
struct wait_queue **assassin = (struct wait_queue **) ptr;
unsigned long oldflags;
int rounds = 0;
MOD_INC_USE_COUNT;
lock_kernel();
/*
* Let our maker know we're running ...
*/
rpciod_pid = current->pid;
up(&rpciod_running);
exit_files(current);
exit_mm(current);
spin_lock_irq(¤t->sigmask_lock);
siginitsetinv(¤t->blocked, sigmask(SIGKILL));
recalc_sigpending(current);
spin_unlock_irq(¤t->sigmask_lock);
current->session = 1;
current->pgrp = 1;
sprintf(current->comm, "rpciod");
dprintk("RPC: rpciod starting (pid %d)\n", rpciod_pid);
while (rpciod_users) {
if (signalled()) {
rpciod_killall();
flush_signals(current);
}
__rpc_schedule();
if (++rounds >= 64) { /* safeguard */
schedule();
rounds = 0;
}
save_flags(oldflags); cli();
dprintk("RPC: rpciod running checking dispatch\n");
rpciod_tcp_dispatcher();
if (!schedq.task) {
dprintk("RPC: rpciod back to sleep\n");
interruptible_sleep_on(&rpciod_idle);
dprintk("RPC: switch to rpciod\n");
rpciod_tcp_dispatcher();
rounds = 0;
}
restore_flags(oldflags);
}
dprintk("RPC: rpciod shutdown commences\n");
if (all_tasks) {
printk(KERN_ERR "rpciod: active tasks at shutdown?!\n");
rpciod_killall();
}
rpciod_pid = 0;
wake_up(assassin);
dprintk("RPC: rpciod exiting\n");
MOD_DEC_USE_COUNT;
return 0;
}
/*
* This creates a new process as a copy of the old one,
* but does not actually start it yet.
*
* It copies the registers, and all the appropriate
* parts of the process environment (as per the clone
* flags). The actual kick-off is left to the caller.
*/
struct task_struct *copy_process(unsigned long clone_flags,
unsigned long stack_start,
struct pt_regs *regs,
unsigned long stack_size,
int *parent_tidptr,
int *child_tidptr)
{
int retval;
struct task_struct *p = NULL;
if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
return ERR_PTR(-EINVAL);
/*
* Thread groups must share signals as well, and detached threads
* can only be started up within the thread group.
*/
if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
return ERR_PTR(-EINVAL);
if ((clone_flags & CLONE_DETACHED) && !(clone_flags & CLONE_THREAD))
return ERR_PTR(-EINVAL);
if (!(clone_flags & CLONE_DETACHED) && (clone_flags & CLONE_THREAD))
return ERR_PTR(-EINVAL);
retval = -ENOMEM;
p = dup_task_struct(current);
if (!p)
goto fork_out;
p->tux_info = NULL;
retval = -EAGAIN;
/*
* Increment user->__count before the rlimit test so that it would
* be correct if we take the bad_fork_free failure path.
*/
atomic_inc(&p->user->__count);
if (atomic_read(&p->user->processes) >= p->rlim[RLIMIT_NPROC].rlim_cur) {
if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE))
goto bad_fork_free;
}
atomic_inc(&p->user->processes);
/*
* Counter increases are protected by
* the kernel lock so nr_threads can't
* increase under us (but it may decrease).
*/
if (nr_threads >= max_threads)
goto bad_fork_cleanup_count;
get_exec_domain(p->exec_domain);
if (p->binfmt && p->binfmt->module)
__MOD_INC_USE_COUNT(p->binfmt->module);
p->did_exec = 0;
p->swappable = 0;
p->state = TASK_UNINTERRUPTIBLE;
copy_flags(clone_flags, p);
if (clone_flags & CLONE_IDLETASK)
p->pid = 0;
else {
p->pid = alloc_pidmap();
if (p->pid == -1)
goto bad_fork_cleanup;
}
retval = -EFAULT;
if (clone_flags & CLONE_PARENT_SETTID)
if (put_user(p->pid, parent_tidptr))
goto bad_fork_cleanup;
INIT_LIST_HEAD(&p->run_list);
INIT_LIST_HEAD(&p->children);
INIT_LIST_HEAD(&p->sibling);
init_waitqueue_head(&p->wait_chldexit);
p->vfork_done = NULL;
spin_lock_init(&p->alloc_lock);
spin_lock_init(&p->switch_lock);
p->sigpending = 0;
init_sigpending(&p->pending);
p->it_real_value = p->it_virt_value = p->it_prof_value = 0;
p->it_real_incr = p->it_virt_incr = p->it_prof_incr = 0;
init_timer(&p->real_timer);
p->real_timer.data = (unsigned long) p;
p->leader = 0; /* session leadership doesn't inherit */
p->tty_old_pgrp = 0;
memset(&p->utime, 0, sizeof(p->utime));
memset(&p->stime, 0, sizeof(p->stime));
memset(&p->cutime, 0, sizeof(p->cutime));
memset(&p->cstime, 0, sizeof(p->cstime));
memset(&p->group_utime, 0, sizeof(p->group_utime));
memset(&p->group_stime, 0, sizeof(p->group_stime));
memset(&p->group_cutime, 0, sizeof(p->group_cutime));
memset(&p->group_cstime, 0, sizeof(p->group_cstime));
#ifdef CONFIG_SMP
memset(&p->per_cpu_utime, 0, sizeof(p->per_cpu_utime));
memset(&p->per_cpu_stime, 0, sizeof(p->per_cpu_stime));
#endif
memset(&p->timing_state, 0, sizeof(p->timing_state));
p->timing_state.type = PROCESS_TIMING_USER;
p->last_sigxcpu = 0;
p->array = NULL;
p->lock_depth = -1; /* -1 = no lock */
p->start_time = jiffies;
retval = -ENOMEM;
/* copy all the process information */
if (copy_files(clone_flags, p))
goto bad_fork_cleanup;
if (copy_fs(clone_flags, p))
goto bad_fork_cleanup_files;
if (copy_sighand(clone_flags, p))
goto bad_fork_cleanup_fs;
if (copy_signal(clone_flags, p))
goto bad_fork_cleanup_sighand;
if (copy_mm(clone_flags, p))
goto bad_fork_cleanup_signal;
if (copy_namespace(clone_flags, p))
goto bad_fork_cleanup_mm;
retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
if (retval)
goto bad_fork_cleanup_namespace;
p->semundo = NULL;
p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID)
? child_tidptr : NULL;
/*
* Clear TID on mm_release()?
*/
p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID)
? child_tidptr : NULL;
/* Our parent execution domain becomes current domain
These must match for thread signalling to apply */
p->parent_exec_id = p->self_exec_id;
/* ok, now we should be set up.. */
p->swappable = 1;
if (clone_flags & CLONE_DETACHED)
p->exit_signal = -1;
else
p->exit_signal = clone_flags & CSIGNAL;
p->pdeath_signal = 0;
/*
* Share the timeslice between parent and child, thus the
* total amount of pending timeslices in the system doesnt change,
* resulting in more scheduling fairness.
*/
local_irq_disable();
p->time_slice = (current->time_slice + 1) >> 1;
p->first_time_slice = 1;
/*
* The remainder of the first timeslice might be recovered by
* the parent if the child exits early enough.
*/
current->time_slice >>= 1;
p->last_run = jiffies;
if (!current->time_slice) {
/*
* This case is rare, it happens when the parent has only
* a single jiffy left from its timeslice. Taking the
* runqueue lock is not a problem.
*/
current->time_slice = 1;
scheduler_tick(0 /* don't update the time stats */);
}
local_irq_enable();
if ((int)current->time_slice <= 0)
BUG();
if ((int)p->time_slice <= 0)
BUG();
/*
* Ok, add it to the run-queues and make it
* visible to the rest of the system.
*
* Let it rip!
*/
p->tgid = p->pid;
p->group_leader = p;
INIT_LIST_HEAD(&p->ptrace_children);
INIT_LIST_HEAD(&p->ptrace_list);
/* Need tasklist lock for parent etc handling! */
write_lock_irq(&tasklist_lock);
/*
* Check for pending SIGKILL! The new thread should not be allowed
* to slip out of an OOM kill. (or normal SIGKILL.)
*/
if (sigismember(¤t->pending.signal, SIGKILL)) {
write_unlock_irq(&tasklist_lock);
retval = -EINTR;
goto bad_fork_cleanup_namespace;
}
/* CLONE_PARENT re-uses the old parent */
if (clone_flags & (CLONE_PARENT|CLONE_THREAD))
p->real_parent = current->real_parent;
else
p->real_parent = current;
p->parent = p->real_parent;
if (clone_flags & CLONE_THREAD) {
spin_lock(¤t->sighand->siglock);
/*
* Important: if an exit-all has been started then
* do not create this new thread - the whole thread
* group is supposed to exit anyway.
*/
if (current->signal->group_exit) {
spin_unlock(¤t->sighand->siglock);
write_unlock_irq(&tasklist_lock);
retval = -EINTR;
goto bad_fork_cleanup_namespace;
}
p->tgid = current->tgid;
p->group_leader = current->group_leader;
if (current->signal->group_stop_count > 0) {
/*
* There is an all-stop in progress for the group.
* We ourselves will stop as soon as we check signals.
* Make the new thread part of that group stop too.
*/
current->signal->group_stop_count++;
p->sigpending = 1;
}
spin_unlock(¤t->sighand->siglock);
}
SET_LINKS(p);
if (p->ptrace & PT_PTRACED)
__ptrace_link(p, current->parent);
attach_pid(p, PIDTYPE_PID, p->pid);
if (thread_group_leader(p)) {
attach_pid(p, PIDTYPE_TGID, p->tgid);
attach_pid(p, PIDTYPE_PGID, p->pgrp);
attach_pid(p, PIDTYPE_SID, p->session);
} else {
link_pid(p, p->pids + PIDTYPE_TGID,
&p->group_leader->pids[PIDTYPE_TGID].pid);
}
/* clear controlling tty of new task if parent's was just cleared */
if (!current->tty && p->tty)
p->tty = NULL;
nr_threads++;
write_unlock_irq(&tasklist_lock);
retval = 0;
fork_out:
if (retval)
return ERR_PTR(retval);
return p;
bad_fork_cleanup_namespace:
exit_namespace(p);
bad_fork_cleanup_mm:
exit_mm(p);
if (p->active_mm)
mmdrop(p->active_mm);
bad_fork_cleanup_signal:
exit_signal(p);
bad_fork_cleanup_sighand:
exit_sighand(p);
bad_fork_cleanup_fs:
exit_fs(p); /* blocking */
bad_fork_cleanup_files:
exit_files(p); /* blocking */
bad_fork_cleanup:
if (p->pid > 0)
free_pidmap(p->pid);
put_exec_domain(p->exec_domain);
if (p->binfmt && p->binfmt->module)
__MOD_DEC_USE_COUNT(p->binfmt->module);
bad_fork_cleanup_count:
atomic_dec(&p->user->processes);
bad_fork_free:
p->state = TASK_ZOMBIE; /* debug */
atomic_dec(&p->usage);
put_task_struct(p);
goto fork_out;
}
