static void
autogroup_move_group(struct task_struct *p, struct autogroup *ag)
{
struct autogroup *prev;
struct task_struct *t;
unsigned long flags;
BUG_ON(!lock_task_sighand(p, &flags));
prev = p->signal->autogroup;
if (prev == ag) {
unlock_task_sighand(p, &flags);
return;
}
p->signal->autogroup = autogroup_kref_get(ag);
/*
* We can't avoid sched_move_task() after we changed signal->autogroup,
* this process can already run with task_group() == prev->tg or we can
* race with cgroup code which can read autogroup = prev under rq->lock.
* In the latter case for_each_thread() can not miss a migrating thread,
* cpu_cgroup_attach() must not be possible after cgroup_exit() and it
* can't be removed from thread list, we hold ->siglock.
*
* If an exiting thread was already removed from thread list we rely on
* sched_autogroup_exit_task().
*/
for_each_thread(p, t)
sched_move_task(t);
unlock_task_sighand(p, &flags);
autogroup_kref_put(prev);
}
SYSCALL_DEFINE2( smunch, int, pid, unsigned long, bit_pattern) {
struct task_struct *target;
unsigned long flags;
rcu_read_lock();
target=find_task_by_vpid(pid);
rcu_read_unlock();
if(!target) {
printk(KERN_ALERT "TARGET DOESNT EXIST\n");
return -1;}
if(!lock_task_sighand(target, &flags)) {
printk(KERN_ALERT "Could not acquire sighand lock\n");
return -1;}
if(!thread_group_empty(target)) {
printk(KERN_ALERT "Multi threaded process\n");
unlock_task_sighand(target , &flags);
return -1;
}
if((target->exit_state & (EXIT_ZOMBIE | EXIT_DEAD)) && (bit_pattern & (1<<(SIGKILL-1)))) {
printk(KERN_ALERT " killing process with PID %d\n",pid);
unlock_task_sighand(target, &flags);
release_task(target);
}
else {
sigaddsetmask(&(target->signal->shared_pending.signal),bit_pattern);
wake_up_process(target);
unlock_task_sighand(target, &flags);
}
return 0;
}
static void
autogroup_move_group(struct task_struct *p, struct autogroup *ag)
{
struct autogroup *prev;
struct task_struct *t;
unsigned long flags;
BUG_ON(!lock_task_sighand(p, &flags));
prev = p->signal->autogroup;
if (prev == ag) {
unlock_task_sighand(p, &flags);
return;
}
p->signal->autogroup = autogroup_kref_get(ag);
if (!ACCESS_ONCE(sysctl_sched_autogroup_enabled))
goto out;
t = p;
do {
sched_move_task(t);
} while_each_thread(p, t);
out:
unlock_task_sighand(p, &flags);
autogroup_kref_put(prev);
}
static int posix_cpu_clock_get_task(struct task_struct *tsk,
const clockid_t which_clock,
struct timespec *tp)
{
int err = -EINVAL;
unsigned long long rtn;
if (CPUCLOCK_PERTHREAD(which_clock)) {
if (same_thread_group(tsk, current))
err = cpu_clock_sample(which_clock, tsk, &rtn);
} else {
unsigned long flags;
struct sighand_struct *sighand;
/*
* while_each_thread() is not yet entirely RCU safe,
* keep locking the group while sampling process
* clock for now.
*/
sighand = lock_task_sighand(tsk, &flags);
if (!sighand)
return err;
if (tsk == current || thread_group_leader(tsk))
err = cpu_clock_sample_group(which_clock, tsk, &rtn);
unlock_task_sighand(tsk, &flags);
}
if (!err)
sample_to_timespec(which_clock, rtn, tp);
return err;
}
/*
* Clean up a CPU-clock timer that is about to be destroyed.
* This is called from timer deletion with the timer already locked.
* If we return TIMER_RETRY, it's necessary to release the timer's lock
* and try again. (This happens when the timer is in the middle of firing.)
*/
static int posix_cpu_timer_del(struct k_itimer *timer)
{
int ret = 0;
unsigned long flags;
struct sighand_struct *sighand;
struct task_struct *p = timer->it.cpu.task;
WARN_ON_ONCE(p == NULL);
/*
* Protect against sighand release/switch in exit/exec and process/
* thread timer list entry concurrent read/writes.
*/
sighand = lock_task_sighand(p, &flags);
if (unlikely(sighand == NULL)) {
/*
* We raced with the reaping of the task.
* The deletion should have cleared us off the list.
*/
WARN_ON_ONCE(!list_empty(&timer->it.cpu.entry));
} else {
if (timer->it.cpu.firing)
ret = TIMER_RETRY;
else
list_del(&timer->it.cpu.entry);
unlock_task_sighand(p, &flags);
}
if (!ret)
put_task_struct(p);
return ret;
}
int tty_audit_push_task(struct task_struct *tsk, uid_t loginuid, u32 sessionid)
{
struct tty_audit_buf *buf = ERR_PTR(-EPERM);
unsigned long flags;
if (!lock_task_sighand(tsk, &flags))
return -ESRCH;
if (tsk->signal->audit_tty) {
buf = tsk->signal->tty_audit_buf;
if (buf)
atomic_inc(&buf->count);
}
unlock_task_sighand(tsk, &flags);
/*
*/
if (!buf || IS_ERR(buf))
return PTR_ERR(buf);
mutex_lock(&buf->mutex);
tty_audit_buf_push(tsk, loginuid, sessionid, buf);
mutex_unlock(&buf->mutex);
tty_audit_buf_put(buf);
return 0;
}
/**
* tty_audit_push_current - Flush current's pending audit data
*
* Try to lock sighand and get a reference to the tty audit buffer if available.
* Flush the buffer or return an appropriate error code.
*/
int tty_audit_push_current(void)
{
struct tty_audit_buf *buf = ERR_PTR(-EPERM);
struct task_struct *tsk = current;
unsigned long flags;
if (!lock_task_sighand(tsk, &flags))
return -ESRCH;
if (tsk->signal->audit_tty) {
buf = tsk->signal->tty_audit_buf;
if (buf)
atomic_inc(&buf->count);
}
unlock_task_sighand(tsk, &flags);
/*
* Return 0 when signal->audit_tty set
* but tsk->signal->tty_audit_buf == NULL.
*/
if (!buf || IS_ERR(buf))
return PTR_ERR(buf);
mutex_lock(&buf->mutex);
tty_audit_buf_push(buf);
mutex_unlock(&buf->mutex);
tty_audit_buf_put(buf);
return 0;
}
static void fake_signal_wake_up(struct task_struct *p)
{
unsigned long flags;
if (lock_task_sighand(p, &flags)) {
signal_wake_up(p, 0);
unlock_task_sighand(p, &flags);
}
}
static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
{
struct task_struct *t;
unsigned long flags;
cputime_t utime, stime;
memset((char *) r, 0, sizeof *r);
utime = stime = cputime_zero;
rcu_read_lock();
if (!lock_task_sighand(p, &flags)) {
rcu_read_unlock();
return;
}
switch (who) {
case RUSAGE_BOTH:
case RUSAGE_CHILDREN:
utime = p->signal->cutime;
stime = p->signal->cstime;
r->ru_nvcsw = p->signal->cnvcsw;
r->ru_nivcsw = p->signal->cnivcsw;
r->ru_minflt = p->signal->cmin_flt;
r->ru_majflt = p->signal->cmaj_flt;
if (who == RUSAGE_CHILDREN)
break;
case RUSAGE_SELF:
utime = cputime_add(utime, p->signal->utime);
stime = cputime_add(stime, p->signal->stime);
r->ru_nvcsw += p->signal->nvcsw;
r->ru_nivcsw += p->signal->nivcsw;
r->ru_minflt += p->signal->min_flt;
r->ru_majflt += p->signal->maj_flt;
t = p;
do {
utime = cputime_add(utime, t->utime);
stime = cputime_add(stime, t->stime);
r->ru_nvcsw += t->nvcsw;
r->ru_nivcsw += t->nivcsw;
r->ru_minflt += t->min_flt;
r->ru_majflt += t->maj_flt;
t = next_thread(t);
} while (t != p);
break;
default:
BUG();
}
unlock_task_sighand(p, &flags);
rcu_read_unlock();
cputime_to_timeval(utime, &r->ru_utime);
cputime_to_timeval(stime, &r->ru_stime);
}
static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
{
struct task_struct *t;
unsigned long flags;
cputime_t utime, stime;
memset((char *) r, 0, sizeof *r);
utime = stime = cputime_zero;
if (who == RUSAGE_THREAD) {
accumulate_thread_rusage(p, r, &utime, &stime);
goto out;
}
if (!lock_task_sighand(p, &flags))
return;
switch (who) {
case RUSAGE_BOTH:
case RUSAGE_CHILDREN:
utime = p->signal->cutime;
stime = p->signal->cstime;
r->ru_nvcsw = p->signal->cnvcsw;
r->ru_nivcsw = p->signal->cnivcsw;
r->ru_minflt = p->signal->cmin_flt;
r->ru_majflt = p->signal->cmaj_flt;
r->ru_inblock = p->signal->cinblock;
r->ru_oublock = p->signal->coublock;
if (who == RUSAGE_CHILDREN)
break;
case RUSAGE_SELF:
utime = cputime_add(utime, p->signal->utime);
stime = cputime_add(stime, p->signal->stime);
r->ru_nvcsw += p->signal->nvcsw;
r->ru_nivcsw += p->signal->nivcsw;
r->ru_minflt += p->signal->min_flt;
r->ru_majflt += p->signal->maj_flt;
r->ru_inblock += p->signal->inblock;
r->ru_oublock += p->signal->oublock;
t = p;
do {
accumulate_thread_rusage(t, r, &utime, &stime);
t = next_thread(t);
} while (t != p);
break;
default:
BUG();
}
unlock_task_sighand(p, &flags);
out:
cputime_to_timeval(utime, &r->ru_utime);
cputime_to_timeval(stime, &r->ru_stime);
}
// Return count of each signal under a process
SYSCALL_DEFINE1(get_sigcounter, int, signumber){
unsigned long flags;
struct task_struct *p;
pid_t pid = current->pid;
p = pid_task(find_vpid(pid), PIDTYPE_PID);
lock_task_sighand(p, &flags);
pr_alert("%d\n", p->sighand->sigcounter[signumber]);
unlock_task_sighand(p, &flags);
return(1);
}
SYSCALL_DEFINE2(smunch,int,pid,unsigned long,bit_pattern)
{
unsigned long flags;
struct task_struct *task;
rcu_read_lock();
task = pid_task(find_vpid(pid),PIDTYPE_PID);
rcu_read_unlock();
if(!task) return -1; // Process not present
if(!lock_task_sighand(task,&flags))
{
//Process refuses to give the lock. Either dead/dying
unlock_task_sighand(task,&flags);
return -1;
}
if(!thread_group_empty(task))
{
printk(KERN_ALERT "\nMULTI-Threaded Process, Exiting without processing");
ret=-1; goto return_path;
}
printk(KERN_ALERT "\nExit State:%XH,State=%XH\n",task->exit_state,task->state); //Info to user
if(task->state & TASK_UNINTERRUPTIBLE)
printk(KERN_ALERT "\nProcess is in Uniterruptible Wait-DeepSleep!!"); // Info to User
if(bit_pattern & (1UL<<(SIGKILL-1)) && (task->exit_state & EXIT_ZOMBIE))
{
printk(KERN_ALERT "\nSIGKILL present while Process is Zombie, releasing task!!");
unlock_task_sighand(task,&flags);
release_task(task); // detach_pid is called from release_task()
return 0;
}
/* If !SIGKILL || (ordinary process) || DeepSleep, sending all signals. It is Users responsility to note that signals will get handled from 1-64 order*/
printk(KERN_ALERT "!SIGKILL || (ordinary process) || DeepSleep, sending all signals!");
task->signal->shared_pending.signal.sig[0] = bit_pattern;
set_tsk_thread_flag(task,TIF_SIGPENDING);
signal_wake_up(task,1);
ret=0;
return_path:
unlock_task_sighand(task,&flags);
return ret;
}
// Initialize count for each signal under a process
SYSCALL_DEFINE1(init_sigcounter, pid_t, pid){
unsigned long flags;
int i;
struct task_struct *p;
p = pid_task(find_vpid(pid), PIDTYPE_PID);
lock_task_sighand(p, &flags);
for(i = 0; i < 64; i++){
p->sighand->sigcounter[i] = 0;
}
unlock_task_sighand(p, &flags);
return(1);
}
static inline struct autogroup *autogroup_task_get(struct task_struct *p)
{
struct autogroup *ag;
unsigned long flags;
if (!lock_task_sighand(p, &flags))
return autogroup_kref_get(&autogroup_default);
ag = autogroup_kref_get(p->signal->autogroup);
unlock_task_sighand(p, &flags);
return ag;
}
int init_sigcounter(int pid){
struct task_struct *p;
struct sighand_struct *sighand;
int i;
unsigned long flags;
p = pid_task(find_vpid(pid), PIDTYPE_PID);
lock_task_sighand(p, &flags);
sighand = p -> sighand;
for(i = 0; i < 64; ++i){
sighand -> sigcounter[i] = 0;
}
unlock_task_sighand(p, &flags);
return 0;
}
static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
{
unsigned long flags;
int error = -ESRCH;
if (lock_task_sighand(child, &flags)) {
error = -EINVAL;
if (likely(child->last_siginfo != NULL)) {
*child->last_siginfo = *info;
error = 0;
}
unlock_task_sighand(child, &flags);
}
return error;
}
static int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
struct core_state *core_state, int exit_code)
{
struct task_struct *g, *p;
unsigned long flags;
int nr = -EAGAIN;
spin_lock_irq(&tsk->sighand->siglock);
if (!signal_group_exit(tsk->signal)) {
mm->core_state = core_state;
nr = zap_process(tsk, exit_code);
tsk->signal->group_exit_task = tsk;
/* ignore all signals except SIGKILL, see prepare_signal() */
tsk->signal->flags = SIGNAL_GROUP_COREDUMP;
clear_tsk_thread_flag(tsk, TIF_SIGPENDING);
}
spin_unlock_irq(&tsk->sighand->siglock);
if (unlikely(nr < 0))
return nr;
tsk->flags = PF_DUMPCORE;
if (atomic_read(&mm->mm_users) == nr + 1)
goto done;
/*
* We should find and kill all tasks which use this mm, and we should
* count them correctly into ->nr_threads. We don't take tasklist
* lock, but this is safe wrt:
*
* fork:
* None of sub-threads can fork after zap_process(leader). All
* processes which were created before this point should be
* visible to zap_threads() because copy_process() adds the new
* process to the tail of init_task.tasks list, and lock/unlock
* of ->siglock provides a memory barrier.
*
* do_exit:
* The caller holds mm->mmap_sem. This means that the task which
* uses this mm can't pass exit_mm(), so it can't exit or clear
* its ->mm.
*
* de_thread:
* It does list_replace_rcu(&leader->tasks, ¤t->tasks),
* we must see either old or new leader, this does not matter.
* However, it can change p->sighand, so lock_task_sighand(p)
* must be used. Since p->mm != NULL and we hold ->mmap_sem
* it can't fail.
*
* Note also that "g" can be the old leader with ->mm == NULL
* and already unhashed and thus removed from ->thread_group.
* This is OK, __unhash_process()->list_del_rcu() does not
* clear the ->next pointer, we will find the new leader via
* next_thread().
*/
rcu_read_lock();
for_each_process(g) {
if (g == tsk->group_leader)
continue;
if (g->flags & PF_KTHREAD)
continue;
p = g;
do {
if (p->mm) {
if (unlikely(p->mm == mm)) {
lock_task_sighand(p, &flags);
nr += zap_process(p, exit_code);
p->signal->flags = SIGNAL_GROUP_EXIT;
unlock_task_sighand(p, &flags);
}
break;
}
} while_each_thread(g, p);
}
rcu_read_unlock();
done:
atomic_set(&core_state->nr_threads, nr);
return nr;
}
static int task_get_unused_fd_flags(struct shfile_proc *proc, int flags)
{
struct files_struct *files = proc->files;
int fd, error;
struct fdtable *fdt;
unsigned long rlim_cur;
unsigned long irqs;
if (files == NULL)
return -ESRCH;
error = -EMFILE;
spin_lock(&files->file_lock);
repeat:
fdt = files_fdtable(files);
fd = find_next_zero_bit(fdt->open_fds, fdt->max_fds, files->next_fd);
/*
* N.B. For clone tasks sharing a files structure, this test
* will limit the total number of files that can be opened.
*/
rlim_cur = 0;
if (lock_task_sighand(proc->tsk, &irqs)) {
rlim_cur = proc->tsk->signal->rlim[RLIMIT_NOFILE].rlim_cur;
unlock_task_sighand(proc->tsk, &irqs);
}
if (fd >= rlim_cur)
goto out;
/* Do we need to expand the fd array or fd set? */
error = expand_files(files, fd);
if (error < 0)
goto out;
if (error) {
/*
* If we needed to expand the fs array we
* might have blocked - try again.
*/
error = -EMFILE;
goto repeat;
}
__set_open_fd(fd, fdt);
if (flags & O_CLOEXEC)
__set_close_on_exec(fd, fdt);
else
__clear_close_on_exec(fd, fdt);
files->next_fd = fd + 1;
#if 1
/* Sanity check */
if (fdt->fd[fd] != NULL) {
printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd);
fdt->fd[fd] = NULL;
}
#endif
error = fd;
out:
spin_unlock(&files->file_lock);
return error;
}
static int
ptrace_start(long pid, long request,
struct task_struct **childp,
struct utrace_attached_engine **enginep,
struct ptrace_state **statep)
{
struct task_struct *child;
struct utrace_attached_engine *engine;
struct ptrace_state *state;
int ret;
NO_LOCKS;
if (request == PTRACE_TRACEME)
return ptrace_traceme();
ret = -ESRCH;
read_lock(&tasklist_lock);
child = find_task_by_pid(pid);
if (child)
get_task_struct(child);
read_unlock(&tasklist_lock);
pr_debug("ptrace pid %ld => %p\n", pid, child);
if (!child)
goto out;
ret = -EPERM;
if (pid == 1) /* you may not mess with init */
goto out_tsk;
if (request == PTRACE_ATTACH) {
ret = ptrace_attach(child);
goto out_tsk;
}
rcu_read_lock();
engine = utrace_attach(child, UTRACE_ATTACH_MATCH_OPS,
&ptrace_utrace_ops, NULL);
ret = -ESRCH;
if (IS_ERR(engine) || engine == NULL)
goto out_tsk_rcu;
state = rcu_dereference(engine->data);
if (state == NULL || state->parent != current)
goto out_tsk_rcu;
/*
* Traditional ptrace behavior demands that the target already be
* quiescent, but not dead.
*/
if (request != PTRACE_KILL
&& !(engine->flags & UTRACE_ACTION_QUIESCE)) {
/*
* If it's in job control stop, turn it into proper quiescence.
*/
struct sighand_struct *sighand;
unsigned long flags;
sighand = lock_task_sighand(child, &flags);
if (likely(sighand != NULL)) {
if (child->state == TASK_STOPPED)
ret = 0;
unlock_task_sighand(child, &flags);
}
if (ret == 0) {
ret = ptrace_update(child, state,
UTRACE_ACTION_QUIESCE, 0);
if (unlikely(ret == -EALREADY))
ret = -ESRCH;
if (unlikely(ret))
BUG_ON(ret != -ESRCH);
}
if (ret) {
pr_debug("%d not stopped (%lu)\n",
child->pid, child->state);
goto out_tsk_rcu;
}
ret = -ESRCH; /* Return value for exit_state bail-out. */
}
atomic_inc(&state->refcnt);
rcu_read_unlock();
NO_LOCKS;
/*
* We do this for all requests to match traditional ptrace behavior.
* If the machine state synchronization done at context switch time
* includes e.g. writing back to user memory, we want to make sure
* that has finished before a PTRACE_PEEKDATA can fetch the results.
* On most machines, only regset data is affected by context switch
* and calling utrace_regset later on will take care of that, so
* this is superfluous.
*
* To do this purely in utrace terms, we could do:
* (void) utrace_regset(child, engine, utrace_native_view(child), 0);
*/
if (request != PTRACE_KILL) {
wait_task_inactive(child);
while (child->state != TASK_TRACED && child->state != TASK_STOPPED) {
if (child->exit_state) {
__ptrace_state_free(state);
goto out_tsk;
}
task_lock(child);
if (child->mm && child->mm->core_waiters) {
task_unlock(child);
__ptrace_state_free(state);
goto out_tsk;
}
task_unlock(child);
/*
* This is a dismal kludge, but it only comes up on ia64.
* It might be blocked inside regset->writeback() called
* from ptrace_report(), when it's on its way to quiescing
* in TASK_TRACED real soon now. We actually need that
* writeback call to have finished, before a PTRACE_PEEKDATA
* here, for example. So keep waiting until it's really there.
*/
yield();
wait_task_inactive(child);
}
}
wait_task_inactive(child);
*childp = child;
*enginep = engine;
*statep = state;
return -EIO;
out_tsk_rcu:
rcu_read_unlock();
out_tsk:
NO_LOCKS;
put_task_struct(child);
out:
return ret;
}
void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
{
unsigned long nr_switches;
unsigned long flags;
int num_threads = 1;
if (lock_task_sighand(p, &flags)) {
num_threads = atomic_read(&p->signal->count);
unlock_task_sighand(p, &flags);
}
SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid, num_threads);
SEQ_printf(m,
"---------------------------------------------------------\n");
#define __P(F) \
SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)F)
#define P(F) \
SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)p->F)
#define __PN(F) \
SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
#define PN(F) \
SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
PN(se.exec_start);
PN(se.vruntime);
PN(se.sum_exec_runtime);
PN(se.avg_overlap);
PN(se.avg_wakeup);
PN(se.avg_running);
nr_switches = p->nvcsw + p->nivcsw;
#ifdef CONFIG_SCHEDSTATS
PN(se.wait_start);
PN(se.sleep_start);
PN(se.block_start);
PN(se.sleep_max);
PN(se.block_max);
PN(se.exec_max);
PN(se.slice_max);
PN(se.wait_max);
PN(se.wait_sum);
P(se.wait_count);
PN(se.iowait_sum);
P(se.iowait_count);
P(sched_info.bkl_count);
P(se.nr_migrations);
P(se.nr_migrations_cold);
P(se.nr_failed_migrations_affine);
P(se.nr_failed_migrations_running);
P(se.nr_failed_migrations_hot);
P(se.nr_forced_migrations);
P(se.nr_wakeups);
P(se.nr_wakeups_sync);
P(se.nr_wakeups_migrate);
P(se.nr_wakeups_local);
P(se.nr_wakeups_remote);
P(se.nr_wakeups_affine);
P(se.nr_wakeups_affine_attempts);
P(se.nr_wakeups_passive);
P(se.nr_wakeups_idle);
{
u64 avg_atom, avg_per_cpu;
avg_atom = p->se.sum_exec_runtime;
if (nr_switches)
do_div(avg_atom, nr_switches);
else
avg_atom = -1LL;
avg_per_cpu = p->se.sum_exec_runtime;
if (p->se.nr_migrations) {
avg_per_cpu = div64_u64(avg_per_cpu,
p->se.nr_migrations);
} else {
avg_per_cpu = -1LL;
}
__PN(avg_atom);
__PN(avg_per_cpu);
}
#endif
__P(nr_switches);
SEQ_printf(m, "%-35s:%21Ld\n",
"nr_voluntary_switches", (long long)p->nvcsw);
SEQ_printf(m, "%-35s:%21Ld\n",
"nr_involuntary_switches", (long long)p->nivcsw);
P(se.load.weight);
P(policy);
P(prio);
#undef PN
#undef __PN
#undef P
#undef __P
{
unsigned int this_cpu = raw_smp_processor_id();
u64 t0, t1;
t0 = cpu_clock(this_cpu);
t1 = cpu_clock(this_cpu);
SEQ_printf(m, "%-35s:%21Ld\n",
"clock-delta", (long long)(t1-t0));
}
}