struct task_struct *kthread_create(int (*threadfn)(void *data),
void *data,
const char namefmt[],
...)
{
struct kthread_create_info create;
DECLARE_WORK(work, keventd_create_kthread, &create);
create.threadfn = threadfn;
create.data = data;
init_completion(&create.started);
init_completion(&create.done);
/*
* The workqueue needs to start up first:
*/
if (!helper_wq)
work.func(work.data);
else {
queue_work(helper_wq, &work);
wait_for_completion(&create.done);
}
if (!IS_ERR(create.result)) {
va_list args;
va_start(args, namefmt);
vsnprintf(create.result->comm, sizeof(create.result->comm),
namefmt, args);
va_end(args);
}
return create.result;
}
/**
* call_usermodehelper_keys - start a usermode application
* @path: pathname for the application
* @argv: null-terminated argument list
* @envp: null-terminated environment list
* @session_keyring: session keyring for process (NULL for an empty keyring)
* @wait: wait for the application to finish and return status.
*
* Runs a user-space application. The application is started
* asynchronously if wait is not set, and runs as a child of keventd.
* (ie. it runs with full root capabilities).
*
* Must be called from process context. Returns a negative error code
* if program was not execed successfully, or 0.
*/
int call_usermodehelper_keys(char *path, char **argv, char **envp,
struct key *session_keyring, int wait)
{
DECLARE_COMPLETION(done);
struct subprocess_info sub_info = {
.complete = &done,
.path = path,
.argv = argv,
.envp = envp,
.ring = session_keyring,
.wait = wait,
.retval = 0,
};
DECLARE_WORK(work, __call_usermodehelper, &sub_info);
OSA_REGISTER_SPINLOCK(&done.wait.lock, "wait_queue_head_t->lock", 23);
if (!khelper_wq)
return -EBUSY;
if (path[0] == '\0')
return 0;
queue_work(khelper_wq, &work);
wait_for_completion(&done);
return sub_info.retval;
}
EXPORT_SYMBOL(call_usermodehelper_keys);
void __init usermodehelper_init(void)
{
khelper_wq = create_singlethread_workqueue("khelper");
BUG_ON(!khelper_wq);
}
/**
* kthread_create - create a kthread.
* @threadfn: the function to run until signal_pending(current).
* @data: data ptr for @threadfn.
* @namefmt: printf-style name for the thread.
*
* Description: This helper function creates and names a kernel
* thread. The thread will be stopped: use wake_up_process() to start
* it. See also kthread_run(), kthread_create_on_cpu().
*
* When woken, the thread will run @threadfn() with @data as its
* argument. @threadfn can either call do_exit() directly if it is a
* standalone thread for which noone will call kthread_stop(), or
* return when 'kthread_should_stop()' is true (which means
* kthread_stop() has been called). The return value should be zero
* or a negative error number; it will be passed to kthread_stop().
*
* Returns a task_struct or ERR_PTR(-ENOMEM).
*/
struct task_struct *kthread_create(int (*threadfn)(void *data),
void *data,
const char namefmt[],
...)
{
struct kthread_create_info create;
DECLARE_WORK(work, keventd_create_kthread, &create);
create.threadfn = threadfn;
create.data = data;
init_completion(&create.started);
init_completion(&create.done);
/*
* The workqueue needs to start up first:
*/
if (!helper_wq)
work.func(work.data);
else {
queue_work(helper_wq, &work);
wait_for_completion(&create.done);
}
if (!IS_ERR(create.result)) {
va_list args;
va_start(args, namefmt);
vsnprintf(create.result->comm, sizeof(create.result->comm),
namefmt, args);
va_end(args);
#ifdef CONFIG_TIVO
int i;
int bFound = 0;
for (i=0; i<sizeof(s_tvKthreadInfoTable)/sizeof(TvKthreadInfo); i++)
{
if (!strcmp(s_tvKthreadInfoTable[i].name, create.result->comm))
{
if (s_tvKthreadInfoTable[i].policy != -1)
{
create.result->policy = s_tvKthreadInfoTable[i].policy;
create.result->rt_priority = s_tvKthreadInfoTable[i].rt_priority;
}
bFound = 1;
break;
}
}
// if (!bFound)
// {
// printk("--- New thread %s is launched with default priority\n", create.result->comm);
// }
#endif
}
return create.result;
}
static int __devinit
do_boot_cpu (int sapicid, int cpu)
{
int timeout;
struct create_idle c_idle = {
.cpu = cpu,
.done = COMPLETION_INITIALIZER(c_idle.done),
};
DECLARE_WORK(work, do_fork_idle, &c_idle);
/*
* We can't use kernel_thread since we must avoid to reschedule the child.
*/
if (!keventd_up() || current_is_keventd())
work.func(work.data);
else {
schedule_work(&work);
wait_for_completion(&c_idle.done);
}
if (IS_ERR(c_idle.idle))
panic("failed fork for CPU %d", cpu);
task_for_booting_cpu = c_idle.idle;
Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
platform_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0);
/*
* Wait 10s total for the AP to start
*/
Dprintk("Waiting on callin_map ...");
for (timeout = 0; timeout < 100000; timeout++) {
if (cpu_isset(cpu, cpu_callin_map))
break; /* It has booted */
udelay(100);
}
Dprintk("\n");
if (!cpu_isset(cpu, cpu_callin_map)) {
printk(KERN_ERR "Processor 0x%x/0x%x is stuck.\n", cpu, sapicid);
ia64_cpu_to_sapicid[cpu] = -1;
cpu_clear(cpu, cpu_online_map); /* was set in smp_callin() */
return -EINVAL;
}
return 0;
}
static int __init
decay (char *str)
{
int ticks;
get_option (&str, &ticks);
return 1;
}
static void __exit producer_mod_cleanup(void)
{
DECLARE_WORK(kill, stop_exec);
continue_exec = 0;
printk(KERN_INFO "--- %s: unloading...\n", mod_name);
printk(KERN_INFO "--- %s: cancel remaining work\n", mod_name);
cancel_delayed_work(&work);
printk(KERN_INFO "--- %s: queue kill request\n", mod_name);
queue_work(wqs, &kill);
printk(KERN_INFO "--- %s: waiting for work to finish...\n", mod_name);
cancel_delayed_work_sync(&work);
cancel_work_sync(&kill);
destroy_workqueue(wqs);
printk(KERN_INFO "--- %s: unloading complete!\n", mod_name);
}
/*
* This is the task which runs the usermode application
*/
static int ____call_usermodehelper(void *data)
{
struct subprocess_info *sub_info = data;
int retval;
/* Install input pipe when needed */
if (sub_info->stdin) {
struct files_struct *f = current->files;
struct fdtable *fdt;
/* no races because files should be private here */
sys_close(0);
fd_install(0, sub_info->stdin);
spin_lock(&f->file_lock);
fdt = files_fdtable(f);
FD_SET(0, fdt->open_fds);
FD_CLR(0, fdt->close_on_exec);
spin_unlock(&f->file_lock);
/* and disallow core files too */
current->signal->rlim[RLIMIT_CORE] = (struct rlimit){0, 0};
}
/* We can run anywhere, unlike our parent keventd(). */
set_cpus_allowed(current, CPU_MASK_ALL);
retval = __exec_usermodehelper(sub_info->path,
sub_info->argv, sub_info->envp, sub_info->ring);
/* Exec failed? */
sub_info->retval = retval;
do_exit(0);
}
/* Keventd can't block, but this (a child) can. */
static int wait_for_helper(void *data)
{
struct subprocess_info *sub_info = data;
pid_t pid;
struct k_sigaction sa;
/* Install a handler: if SIGCLD isn't handled sys_wait4 won't
* populate the status, but will return -ECHILD. */
sa.sa.sa_handler = SIG_IGN;
sa.sa.sa_flags = 0;
siginitset(&sa.sa.sa_mask, sigmask(SIGCHLD));
do_sigaction(SIGCHLD, &sa, NULL);
allow_signal(SIGCHLD);
pid = kernel_thread(____call_usermodehelper, sub_info, SIGCHLD);
if (pid < 0) {
sub_info->retval = pid;
} else {
/*
* Normally it is bogus to call wait4() from in-kernel because
* wait4() wants to write the exit code to a userspace address.
* But wait_for_helper() always runs as keventd, and put_user()
* to a kernel address works OK for kernel threads, due to their
* having an mm_segment_t which spans the entire address space.
*
* Thus the __user pointer cast is valid here.
*/
sys_wait4(pid, (int __user *) &sub_info->retval, 0, NULL);
}
complete(sub_info->complete);
return 0;
}
/* This is run by khelper thread */
static void __call_usermodehelper(void *data)
{
struct subprocess_info *sub_info = data;
pid_t pid;
int wait = sub_info->wait;
/* CLONE_VFORK: wait until the usermode helper has execve'd
* successfully We need the data structures to stay around
* until that is done. */
if (wait)
pid = kernel_thread(wait_for_helper, sub_info,
CLONE_FS | CLONE_FILES | SIGCHLD);
else
pid = kernel_thread(____call_usermodehelper, sub_info,
CLONE_VFORK | SIGCHLD);
if (pid < 0) {
sub_info->retval = pid;
complete(sub_info->complete);
} else if (!wait)
complete(sub_info->complete);
}
/**
* call_usermodehelper_keys - start a usermode application
* @path: pathname for the application
* @argv: null-terminated argument list
* @envp: null-terminated environment list
* @session_keyring: session keyring for process (NULL for an empty keyring)
* @wait: wait for the application to finish and return status.
*
* Runs a user-space application. The application is started
* asynchronously if wait is not set, and runs as a child of keventd.
* (ie. it runs with full root capabilities).
*
* Must be called from process context. Returns a negative error code
* if program was not execed successfully, or 0.
*/
int call_usermodehelper_keys(char *path, char **argv, char **envp,
struct key *session_keyring, int wait)
{
DECLARE_COMPLETION_ONSTACK(done);
struct subprocess_info sub_info = {
.complete = &done,
.path = path,
.argv = argv,
.envp = envp,
.ring = session_keyring,
.wait = wait,
.retval = 0,
};
DECLARE_WORK(work, __call_usermodehelper, &sub_info);
if (!khelper_wq)
return -EBUSY;
if (path[0] == '\0')
return 0;
queue_work(khelper_wq, &work);
wait_for_completion(&done);
return sub_info.retval;
}
EXPORT_SYMBOL(call_usermodehelper_keys);
int call_usermodehelper_pipe(char *path, char **argv, char **envp,
struct file **filp)
{
DECLARE_COMPLETION(done);
struct subprocess_info sub_info = {
.complete = &done,
.path = path,
.argv = argv,
.envp = envp,
.retval = 0,
};
struct file *f;
DECLARE_WORK(work, __call_usermodehelper, &sub_info);
if (!khelper_wq)
return -EBUSY;
if (path[0] == '\0')
return 0;
f = create_write_pipe();
if (!f)
return -ENOMEM;
*filp = f;
f = create_read_pipe(f);
if (!f) {
free_write_pipe(*filp);
return -ENOMEM;
}
sub_info.stdin = f;
queue_work(khelper_wq, &work);
wait_for_completion(&done);
return sub_info.retval;
}
EXPORT_SYMBOL(call_usermodehelper_pipe);
void __init usermodehelper_init(void)
{
khelper_wq = create_singlethread_workqueue("khelper");
BUG_ON(!khelper_wq);
}
