/*
* This is the task which runs the usermode application
*/
static int ____call_usermodehelper(void *data)
{
struct subprocess_info *sub_info = data;
struct key *new_session, *old_session;
int retval;
/* Unblock all signals and set the session keyring. */
new_session = key_get(sub_info->ring);
flush_signals(current);
spin_lock_irq(¤t->sighand->siglock);
old_session = __install_session_keyring(current, new_session);
flush_signal_handlers(current, 1);
sigemptyset(¤t->blocked);
recalc_sigpending();
spin_unlock_irq(¤t->sighand->siglock);
key_put(old_session);
/* We can run anywhere, unlike our parent keventd(). */
set_cpus_allowed(current, CPU_MASK_ALL);
retval = -EPERM;
if (current->fs->root)
retval = execve(sub_info->path, sub_info->argv,sub_info->envp);
/* Exec failed? */
sub_info->retval = retval;
do_exit(0);
}
/*
* This is the task which runs the usermode application
*/
static int ____call_usermodehelper(void *data)
{
struct subprocess_info *sub_info = data;
int retval;
spin_lock_irq(¤t->sighand->siglock);
flush_signal_handlers(current, 1);
spin_unlock_irq(¤t->sighand->siglock);
/* We can run anywhere, unlike our parent keventd(). */
set_cpus_allowed_ptr(current, cpu_all_mask);
/*
* Our parent is keventd, which runs with elevated scheduling priority.
* Avoid propagating that into the userspace child.
*/
set_user_nice(current, 0);
if (sub_info->init) {
retval = sub_info->init(sub_info);
if (retval)
goto fail;
}
retval = kernel_execve(sub_info->path, sub_info->argv, sub_info->envp);
/* Exec failed? */
fail:
sub_info->retval = retval;
do_exit(0);
}
/*
* This is the task which runs the usermode application
*/
static int ____call_usermodehelper(void *data)
{
struct subprocess_info *sub_info = data;
int retval;
//TODO:RAWLINSON
struct cpumask cpu_padrao = cpumask_of_cpu(CPUID_PADRAO);
spin_lock_irq(¤t->sighand->siglock);
flush_signal_handlers(current, 1);
spin_unlock_irq(¤t->sighand->siglock);
/* We can run anywhere, unlike our parent keventd(). */
//TODO:RAWLINSON
//set_cpus_allowed_ptr(current, cpu_all_mask); //TODO:RAWLINSON - CODIGO ORIGINAL...
current->cpus_allowed = cpu_padrao;
set_cpus_allowed_ptr(current, &cpu_padrao);
/*
* Our parent is keventd, which runs with elevated scheduling priority.
* Avoid propagating that into the userspace child.
*/
set_user_nice(current, 0);
if (sub_info->init) {
retval = sub_info->init(sub_info);
if (retval)
goto fail;
}
retval = kernel_execve(sub_info->path,
(const char *const *)sub_info->argv,
(const char *const *)sub_info->envp);
/* Exec failed? */
fail:
sub_info->retval = retval;
do_exit(0);
}
/*
* This is the task which runs the usermode application
*/
int
__exec_usermodehelper(char *path, char **argv, char **envp, struct key *ring)
{
struct key *new_session, *old_session;
int retval;
/* Unblock all signals and set the session keyring. */
new_session = key_get(ring);
flush_signals(current);
spin_lock_irq(¤t->sighand->siglock);
old_session = __install_session_keyring(current, new_session);
flush_signal_handlers(current, 1);
sigemptyset(¤t->blocked);
recalc_sigpending();
spin_unlock_irq(¤t->sighand->siglock);
key_put(old_session);
retval = -EPERM;
if (current->fs->root)
retval = execve(path, argv, envp);
return retval;
}
/*
* This is the task which runs the usermode application
*/
static int ____call_usermodehelper(void *data)
{
struct subprocess_info *sub_info = data;
int retval;
BUG_ON(atomic_read(&sub_info->cred->usage) != 1);
/* Unblock all signals */
spin_lock_irq(¤t->sighand->siglock);
flush_signal_handlers(current, 1);
sigemptyset(¤t->blocked);
recalc_sigpending();
spin_unlock_irq(¤t->sighand->siglock);
/* Install the credentials */
commit_creds(sub_info->cred);
sub_info->cred = NULL;
/* 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_ptr(current, cpu_all_mask);
/*
* Our parent is keventd, which runs with elevated scheduling priority.
* Avoid propagating that into the userspace child.
*/
set_user_nice(current, 0);
if (sub_info->init) {
retval = sub_info->init(sub_info);
if (retval)
goto fail;
}
retval = kernel_execve(sub_info->path, sub_info->argv, sub_info->envp);
/* Exec failed? */
fail:
sub_info->retval = retval;
return 0;
}
void call_usermodehelper_freeinfo(struct subprocess_info *info)
{
if (info->cleanup)
(*info->cleanup)(info);
if (info->cred)
put_cred(info->cred);
kfree(info);
}
EXPORT_SYMBOL(call_usermodehelper_freeinfo);
static void umh_complete(struct subprocess_info *sub_info)
{
struct completion *comp = xchg(&sub_info->complete, NULL);
/*
* See call_usermodehelper_exec(). If xchg() returns NULL
* we own sub_info, the UMH_KILLABLE caller has gone away.
*/
if (comp)
complete(comp);
else
call_usermodehelper_freeinfo(sub_info);
}
/* 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;
/* Install a handler: if SIGCLD isn't handled sys_wait4 won't
* populate the status, but will return -ECHILD. */
allow_signal(SIGCHLD);
pid = kernel_thread(____call_usermodehelper, sub_info, SIGCHLD);
if (pid < 0) {
sub_info->retval = pid;
} else {
int ret;
/*
* 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 *)&ret, 0, NULL);
/*
* If ret is 0, either ____call_usermodehelper failed and the
* real error code is already in sub_info->retval or
* sub_info->retval is 0 anyway, so don't mess with it then.
*/
if (ret)
sub_info->retval = ret;
}
if (sub_info->wait == UMH_NO_WAIT)
call_usermodehelper_freeinfo(sub_info);
else
umh_complete(sub_info);
return 0;
}
/* This is run by khelper thread */
static void __call_usermodehelper(struct work_struct *work)
{
struct subprocess_info *sub_info =
container_of(work, struct subprocess_info, work);
int wait = sub_info->wait & ~UMH_KILLABLE;
pid_t pid;
BUG_ON(atomic_read(&sub_info->cred->usage) != 1);
/* 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 == UMH_WAIT_PROC || wait == UMH_NO_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);
switch (wait) {
case UMH_NO_WAIT:
break;
case UMH_WAIT_PROC:
if (pid > 0)
break;
sub_info->retval = pid;
/* FALLTHROUGH */
case UMH_WAIT_EXEC:
umh_complete(sub_info);
}
}
#ifdef CONFIG_PM_SLEEP
/*
* If set, call_usermodehelper_exec() will exit immediately returning -EBUSY
* (used for preventing user land processes from being created after the user
* land has been frozen during a system-wide hibernation or suspend operation).
* Should always be manipulated under umhelper_sem acquired for write.
*/
static int usermodehelper_disabled;
/* Number of helpers running */
static atomic_t running_helpers = ATOMIC_INIT(0);
/*
* Wait queue head used by usermodehelper_pm_callback() to wait for all running
* helpers to finish.
*/
static DECLARE_WAIT_QUEUE_HEAD(running_helpers_waitq);
/*
* Time to wait for running_helpers to become zero before the setting of
* usermodehelper_disabled in usermodehelper_pm_callback() fails
*/
#define RUNNING_HELPERS_TIMEOUT (5 * HZ)
void read_lock_usermodehelper(void)
{
down_read(&umhelper_sem);
}
