[PATCH v2] cobalt: Sort out virtual vs. real pids

[PATCH v2] cobalt: Sort out virtual vs. real pids

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka@siemens.com>

Make sure that we consider all pids taken from or sent to userspace via
syscalls as virtual. That means converting them to global pids before
processing them or converting them back to virtual pids in the caller's
namespace before reporting them. We also need to switch thread hashing
from vpids to real pids.

Not converted is the procfs interface as this one continues to provide
only a global view on cobalt objects and associated pids.

A few syscall tracepoints that report the vpid as passed down from
userspace get adjusted in their output so that it is clear that no
global pid is shown.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

Changes in v2:
 - fix thread hashing
 - switch back to global pids in relax tracing

 include/cobalt/kernel/thread.h     |  2 ++
 kernel/cobalt/posix/event.c        |  2 +-
 kernel/cobalt/posix/mqueue.c       |  2 +-
 kernel/cobalt/posix/process.c      | 14 ++++++++++++++
 kernel/cobalt/posix/process.h      |  2 ++
 kernel/cobalt/posix/sched.c        | 10 ++++++----
 kernel/cobalt/posix/sem.c          |  2 +-
 kernel/cobalt/posix/signal.c       | 10 ++++++----
 kernel/cobalt/posix/thread.c       | 14 ++++++++------
 kernel/cobalt/thread.c             | 10 ++++++++++
 kernel/cobalt/trace/cobalt-posix.h |  4 ++--
 11 files changed, 53 insertions(+), 19 deletions(-)

diff --git a/include/cobalt/kernel/thread.h b/include/cobalt/kernel/thread.h
index b79cb84296..4c8a0b9f2a 100644
--- a/include/cobalt/kernel/thread.h
+++ b/include/cobalt/kernel/thread.h
@@ -450,6 +450,8 @@ char *xnthread_format_status(unsigned long status,
 
 pid_t xnthread_host_pid(struct xnthread *thread);
 
+pid_t xnthread_host_vpid(struct xnthread *thread);
+
 int xnthread_set_clock(struct xnthread *thread,
 		       struct xnclock *newclock);
 
diff --git a/kernel/cobalt/posix/event.c b/kernel/cobalt/posix/event.c
index 3712154f53..5871106301 100644
--- a/kernel/cobalt/posix/event.c
+++ b/kernel/cobalt/posix/event.c
@@ -352,7 +352,7 @@ COBALT_SYSCALL(event_inquire, current,
 		xnsynch_for_each_sleeper(thread, &event->synch) {
 			if (nrwait >= nrpids)
 				break;
-			t[nrwait++] = xnthread_host_pid(thread);
+			t[nrwait++] = xnthread_host_vpid(thread);
 		}
 	}
 
diff --git a/kernel/cobalt/posix/mqueue.c b/kernel/cobalt/posix/mqueue.c
index dd8acd55b0..fcde87a077 100644
--- a/kernel/cobalt/posix/mqueue.c
+++ b/kernel/cobalt/posix/mqueue.c
@@ -720,7 +720,7 @@ mq_notify(struct cobalt_mqd *mqd, unsigned index, const struct sigevent *evp)
 		 * receiver's namespaces. We pass the receiver's creds
 		 * into the init namespace instead.
 		 */
-		mq->si.si_pid = task_pid_nr(current);
+		mq->si.si_pid = task_pid_vnr(current);
 		mq->si.si_uid = get_current_uuid();
 	}
 
diff --git a/kernel/cobalt/posix/process.c b/kernel/cobalt/posix/process.c
index 1f059ad830..98b7df33fb 100644
--- a/kernel/cobalt/posix/process.c
+++ b/kernel/cobalt/posix/process.c
@@ -975,6 +975,20 @@ int cobalt_handle_cleanup_event(struct mm_struct *mm)
 	return KEVENT_PROPAGATE;
 }
 
+pid_t cobalt_vpid2pid_nr(pid_t vpid)
+{
+	struct pid *pid;
+	pid_t nr = -1;
+
+	rcu_read_lock();
+	pid = find_vpid(vpid);
+	if (pid)
+		nr = pid_nr(pid);
+	rcu_read_unlock();
+
+	return nr;
+}
+
 static int attach_process(struct cobalt_process *process)
 {
 	struct cobalt_ppd *p = &process->sys_ppd;
diff --git a/kernel/cobalt/posix/process.h b/kernel/cobalt/posix/process.h
index 279707a680..46dff43b7a 100644
--- a/kernel/cobalt/posix/process.h
+++ b/kernel/cobalt/posix/process.h
@@ -175,4 +175,6 @@ int cobalt_handle_cleanup_event(struct mm_struct *mm);
 
 int cobalt_handle_user_return(struct task_struct *task);
 
+pid_t cobalt_vpid2pid_nr(pid_t vpid);
+
 #endif /* !_COBALT_POSIX_PROCESS_H */
diff --git a/kernel/cobalt/posix/sched.c b/kernel/cobalt/posix/sched.c
index 4fd9c2b46e..26259fbd3f 100644
--- a/kernel/cobalt/posix/sched.c
+++ b/kernel/cobalt/posix/sched.c
@@ -736,7 +736,7 @@ COBALT_SYSCALL(sched_weightprio, current,
 	return __cobalt_sched_weightprio(policy, &param_ex);
 }
 
-int cobalt_sched_setscheduler_ex(pid_t pid,
+int cobalt_sched_setscheduler_ex(pid_t vpid,
 				 int policy,
 				 const struct sched_param_ex *param_ex,
 				 __u32 __user *u_winoff,
@@ -747,9 +747,11 @@ int cobalt_sched_setscheduler_ex(pid_t pid,
 	int ret, promoted = 0;
 	spl_t s;
 
-	trace_cobalt_sched_setscheduler(pid, policy, param_ex);
+	trace_cobalt_sched_setscheduler(vpid, policy, param_ex);
+
+	if (vpid) {
+		pid_t pid = cobalt_vpid2pid_nr(vpid);
 
-	if (pid) {
 		xnlock_get_irqsave(&nklock, s);
 		thread = cobalt_thread_find(pid);
 		xnlock_put_irqrestore(&nklock, s);
@@ -757,7 +759,7 @@ int cobalt_sched_setscheduler_ex(pid_t pid,
 		thread = cobalt_current_thread();
 
 	if (thread == NULL) {
-		if (u_winoff == NULL || pid != task_pid_vnr(current))
+		if (u_winoff == NULL || vpid != task_pid_vnr(current))
 			return -ESRCH;
 			
 		thread = cobalt_thread_shadow(&hkey, u_winoff);
diff --git a/kernel/cobalt/posix/sem.c b/kernel/cobalt/posix/sem.c
index 72b20c78d2..030ce8ffed 100644
--- a/kernel/cobalt/posix/sem.c
+++ b/kernel/cobalt/posix/sem.c
@@ -602,7 +602,7 @@ COBALT_SYSCALL(sem_inquire, current,
 		xnsynch_for_each_sleeper(thread, &sem->synchbase) {
 			if (nrwait >= nrpids)
 				break;
-			t[nrwait++] = xnthread_host_pid(thread);
+			t[nrwait++] = xnthread_host_vpid(thread);
 		}
 	}
 
diff --git a/kernel/cobalt/posix/signal.c b/kernel/cobalt/posix/signal.c
index 0b43b5fcfa..c2c9c092c4 100644
--- a/kernel/cobalt/posix/signal.c
+++ b/kernel/cobalt/posix/signal.c
@@ -510,7 +510,7 @@ int __cobalt_kill(struct cobalt_thread *thread, int sig, int group) /* nklocked,
 			sigp->si.si_signo = sig;
 			sigp->si.si_errno = 0;
 			sigp->si.si_code = SI_USER;
-			sigp->si.si_pid = task_pid_nr(current);
+			sigp->si.si_pid = task_pid_vnr(current);
 			sigp->si.si_uid = get_current_uuid();
 			if (cobalt_signal_send(thread, sigp, group) <= 0)
 				cobalt_signal_free(sigp);
@@ -525,8 +525,9 @@ int __cobalt_kill(struct cobalt_thread *thread, int sig, int group) /* nklocked,
 	return ret;
 }
 
-COBALT_SYSCALL(kill, conforming, (pid_t pid, int sig))
+COBALT_SYSCALL(kill, conforming, (pid_t vpid, int sig))
 {
+	pid_t pid = cobalt_vpid2pid_nr(vpid);
 	struct cobalt_thread *thread;
 	int ret;
 	spl_t s;
@@ -544,8 +545,9 @@ COBALT_SYSCALL(kill, conforming, (pid_t pid, int sig))
 	return ret;
 }
 
-int __cobalt_sigqueue(pid_t pid, int sig, const union sigval *value)
+int __cobalt_sigqueue(pid_t vpid, int sig, const union sigval *value)
 {
+	pid_t pid = cobalt_vpid2pid_nr(vpid);
 	struct cobalt_sigpending *sigp;
 	struct cobalt_thread *thread;
 	int ret = 0;
@@ -569,7 +571,7 @@ int __cobalt_sigqueue(pid_t pid, int sig, const union sigval *value)
 			sigp->si.si_signo = sig;
 			sigp->si.si_errno = 0;
 			sigp->si.si_code = SI_QUEUE;
-			sigp->si.si_pid = task_pid_nr(current);
+			sigp->si.si_pid = task_pid_vnr(current);
 			sigp->si.si_uid = get_current_uuid();
 			sigp->si.si_value = *value;
 			if (cobalt_signal_send(thread, sigp, 1) <= 0)
diff --git a/kernel/cobalt/posix/thread.c b/kernel/cobalt/posix/thread.c
index cdeb66d4f3..2f3ea1dec4 100644
--- a/kernel/cobalt/posix/thread.c
+++ b/kernel/cobalt/posix/thread.c
@@ -624,7 +624,7 @@ int __cobalt_thread_create(unsigned long pth, int policy,
 		return ret;
 	}
 
-	if (!thread_hash(&hkey, thread, task_pid_vnr(p))) {
+	if (!thread_hash(&hkey, thread, task_pid_nr(p))) {
 		ret = -EAGAIN;
 		goto fail;
 	}
@@ -682,7 +682,7 @@ cobalt_thread_shadow(struct cobalt_local_hkey *hkey,
 		return ERR_PTR(ret);
 	}
 
-	if (!thread_hash(hkey, thread, task_pid_vnr(current))) {
+	if (!thread_hash(hkey, thread, task_pid_nr(current))) {
 		ret = -EAGAIN;
 		goto fail;
 	}
@@ -819,7 +819,7 @@ COBALT_SYSCALL(thread_getpid, current, (unsigned long pth))
 	if (thread == NULL)
 		pid = -ESRCH;
 	else
-		pid = xnthread_host_pid(&thread->threadbase);
+		pid = xnthread_host_vpid(&thread->threadbase);
 
 	xnlock_put_irqrestore(&nklock, s);
 
@@ -827,7 +827,7 @@ COBALT_SYSCALL(thread_getpid, current, (unsigned long pth))
 }
 
 COBALT_SYSCALL(thread_getstat, current,
-	       (pid_t pid, struct cobalt_threadstat __user *u_stat))
+	       (pid_t vpid, struct cobalt_threadstat __user *u_stat))
 {
 	struct cobalt_threadstat stat;
 	struct cobalt_thread *p;
@@ -835,14 +835,16 @@ COBALT_SYSCALL(thread_getstat, current,
 	xnticks_t xtime;
 	spl_t s;
 
-	trace_cobalt_pthread_stat(pid);
+	trace_cobalt_pthread_stat(vpid);
 
-	if (pid == 0) {
+	if (vpid == 0) {
 		thread = xnthread_current();
 		if (thread == NULL)
 			return -EPERM;
 		xnlock_get_irqsave(&nklock, s);
 	} else {
+		pid_t pid = cobalt_vpid2pid_nr(vpid);
+
 		xnlock_get_irqsave(&nklock, s);
 		p = cobalt_thread_find(pid);
 		if (p == NULL) {
diff --git a/kernel/cobalt/thread.c b/kernel/cobalt/thread.c
index 2c1ec6d3a4..9a97213fbe 100644
--- a/kernel/cobalt/thread.c
+++ b/kernel/cobalt/thread.c
@@ -388,6 +388,16 @@ pid_t xnthread_host_pid(struct xnthread *thread)
 	return task_pid_nr(xnthread_host_task(thread));
 }
 
+pid_t xnthread_host_vpid(struct xnthread *thread)
+{
+	if (xnthread_test_state(thread, XNROOT))
+		return 0;
+	if (!xnthread_host_task(thread))
+		return -1;
+
+	return task_pid_vnr(xnthread_host_task(thread));
+}
+
 int xnthread_set_clock(struct xnthread *thread, struct xnclock *newclock)
 {
 	spl_t s;
diff --git a/kernel/cobalt/trace/cobalt-posix.h b/kernel/cobalt/trace/cobalt-posix.h
index 1d623069df..d66053da8d 100644
--- a/kernel/cobalt/trace/cobalt-posix.h
+++ b/kernel/cobalt/trace/cobalt-posix.h
@@ -246,7 +246,7 @@ DECLARE_EVENT_CLASS(cobalt_posix_scheduler,
 		memcpy(__get_dynamic_array(param_ex), param_ex, sizeof(*param_ex));
 	),
 
-	TP_printk("pid=%d policy=%s param={ %s }",
+	TP_printk("vpid=%d policy=%s param={ %s }",
 		  __entry->pid,
 		  cobalt_print_sched_policy(__entry->policy),
 		  __parse_sched_params(__entry->policy,
@@ -363,7 +363,7 @@ DECLARE_EVENT_CLASS(cobalt_posix_pid,
 	TP_fast_assign(
 		__entry->pid = pid;
 	),
-	TP_printk("pid=%d", __entry->pid)
+	TP_printk("vpid=%d", __entry->pid)
 );
 
 DEFINE_EVENT(cobalt_posix_pid, cobalt_pthread_stat,
-- 
2.26.2

Re: [PATCH v2] cobalt: Sort out virtual vs. real pids

[Jan Kiszka]

On 13.07.21 11:46, Jan Kiszka via Xenomai wrote:
> From: Jan Kiszka <jan.kiszka@siemens.com>
> 
> Make sure that we consider all pids taken from or sent to userspace via
> syscalls as virtual. That means converting them to global pids before
> processing them or converting them back to virtual pids in the caller's
> namespace before reporting them. We also need to switch thread hashing
> from vpids to real pids.
> 
> Not converted is the procfs interface as this one continues to provide
> only a global view on cobalt objects and associated pids.
> 
> A few syscall tracepoints that report the vpid as passed down from
> userspace get adjusted in their output so that it is clear that no
> global pid is shown.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
> 
> Changes in v2:
>  - fix thread hashing
>  - switch back to global pids in relax tracing
> 
>  include/cobalt/kernel/thread.h     |  2 ++
>  kernel/cobalt/posix/event.c        |  2 +-
>  kernel/cobalt/posix/mqueue.c       |  2 +-
>  kernel/cobalt/posix/process.c      | 14 ++++++++++++++
>  kernel/cobalt/posix/process.h      |  2 ++
>  kernel/cobalt/posix/sched.c        | 10 ++++++----
>  kernel/cobalt/posix/sem.c          |  2 +-
>  kernel/cobalt/posix/signal.c       | 10 ++++++----
>  kernel/cobalt/posix/thread.c       | 14 ++++++++------
>  kernel/cobalt/thread.c             | 10 ++++++++++
>  kernel/cobalt/trace/cobalt-posix.h |  4 ++--
>  11 files changed, 53 insertions(+), 19 deletions(-)
> 
> diff --git a/include/cobalt/kernel/thread.h b/include/cobalt/kernel/thread.h
> index b79cb84296..4c8a0b9f2a 100644
> --- a/include/cobalt/kernel/thread.h
> +++ b/include/cobalt/kernel/thread.h
> @@ -450,6 +450,8 @@ char *xnthread_format_status(unsigned long status,
>  
>  pid_t xnthread_host_pid(struct xnthread *thread);
>  
> +pid_t xnthread_host_vpid(struct xnthread *thread);
> +
>  int xnthread_set_clock(struct xnthread *thread,
>  		       struct xnclock *newclock);
>  
> diff --git a/kernel/cobalt/posix/event.c b/kernel/cobalt/posix/event.c
> index 3712154f53..5871106301 100644
> --- a/kernel/cobalt/posix/event.c
> +++ b/kernel/cobalt/posix/event.c
> @@ -352,7 +352,7 @@ COBALT_SYSCALL(event_inquire, current,
>  		xnsynch_for_each_sleeper(thread, &event->synch) {
>  			if (nrwait >= nrpids)
>  				break;
> -			t[nrwait++] = xnthread_host_pid(thread);
> +			t[nrwait++] = xnthread_host_vpid(thread);
>  		}
>  	}
>  
> diff --git a/kernel/cobalt/posix/mqueue.c b/kernel/cobalt/posix/mqueue.c
> index dd8acd55b0..fcde87a077 100644
> --- a/kernel/cobalt/posix/mqueue.c
> +++ b/kernel/cobalt/posix/mqueue.c
> @@ -720,7 +720,7 @@ mq_notify(struct cobalt_mqd *mqd, unsigned index, const struct sigevent *evp)
>  		 * receiver's namespaces. We pass the receiver's creds
>  		 * into the init namespace instead.
>  		 */
> -		mq->si.si_pid = task_pid_nr(current);
> +		mq->si.si_pid = task_pid_vnr(current);
>  		mq->si.si_uid = get_current_uuid();
>  	}
>  
> diff --git a/kernel/cobalt/posix/process.c b/kernel/cobalt/posix/process.c
> index 1f059ad830..98b7df33fb 100644
> --- a/kernel/cobalt/posix/process.c
> +++ b/kernel/cobalt/posix/process.c
> @@ -975,6 +975,20 @@ int cobalt_handle_cleanup_event(struct mm_struct *mm)
>  	return KEVENT_PROPAGATE;
>  }
>  
> +pid_t cobalt_vpid2pid_nr(pid_t vpid)
> +{
> +	struct pid *pid;
> +	pid_t nr = -1;
> +
> +	rcu_read_lock();
> +	pid = find_vpid(vpid);
> +	if (pid)
> +		nr = pid_nr(pid);
> +	rcu_read_unlock();
> +
> +	return nr;
> +}
> +
>  static int attach_process(struct cobalt_process *process)
>  {
>  	struct cobalt_ppd *p = &process->sys_ppd;
> diff --git a/kernel/cobalt/posix/process.h b/kernel/cobalt/posix/process.h
> index 279707a680..46dff43b7a 100644
> --- a/kernel/cobalt/posix/process.h
> +++ b/kernel/cobalt/posix/process.h
> @@ -175,4 +175,6 @@ int cobalt_handle_cleanup_event(struct mm_struct *mm);
>  
>  int cobalt_handle_user_return(struct task_struct *task);
>  
> +pid_t cobalt_vpid2pid_nr(pid_t vpid);
> +
>  #endif /* !_COBALT_POSIX_PROCESS_H */
> diff --git a/kernel/cobalt/posix/sched.c b/kernel/cobalt/posix/sched.c
> index 4fd9c2b46e..26259fbd3f 100644
> --- a/kernel/cobalt/posix/sched.c
> +++ b/kernel/cobalt/posix/sched.c
> @@ -736,7 +736,7 @@ COBALT_SYSCALL(sched_weightprio, current,
>  	return __cobalt_sched_weightprio(policy, &param_ex);
>  }
>  
> -int cobalt_sched_setscheduler_ex(pid_t pid,
> +int cobalt_sched_setscheduler_ex(pid_t vpid,
>  				 int policy,
>  				 const struct sched_param_ex *param_ex,
>  				 __u32 __user *u_winoff,
> @@ -747,9 +747,11 @@ int cobalt_sched_setscheduler_ex(pid_t pid,
>  	int ret, promoted = 0;
>  	spl_t s;
>  
> -	trace_cobalt_sched_setscheduler(pid, policy, param_ex);
> +	trace_cobalt_sched_setscheduler(vpid, policy, param_ex);
> +
> +	if (vpid) {
> +		pid_t pid = cobalt_vpid2pid_nr(vpid);
>  
> -	if (pid) {
>  		xnlock_get_irqsave(&nklock, s);
>  		thread = cobalt_thread_find(pid);
>  		xnlock_put_irqrestore(&nklock, s);
> @@ -757,7 +759,7 @@ int cobalt_sched_setscheduler_ex(pid_t pid,
>  		thread = cobalt_current_thread();
>  
>  	if (thread == NULL) {
> -		if (u_winoff == NULL || pid != task_pid_vnr(current))
> +		if (u_winoff == NULL || vpid != task_pid_vnr(current))
>  			return -ESRCH;
>  			
>  		thread = cobalt_thread_shadow(&hkey, u_winoff);
> diff --git a/kernel/cobalt/posix/sem.c b/kernel/cobalt/posix/sem.c
> index 72b20c78d2..030ce8ffed 100644
> --- a/kernel/cobalt/posix/sem.c
> +++ b/kernel/cobalt/posix/sem.c
> @@ -602,7 +602,7 @@ COBALT_SYSCALL(sem_inquire, current,
>  		xnsynch_for_each_sleeper(thread, &sem->synchbase) {
>  			if (nrwait >= nrpids)
>  				break;
> -			t[nrwait++] = xnthread_host_pid(thread);
> +			t[nrwait++] = xnthread_host_vpid(thread);
>  		}
>  	}
>  
> diff --git a/kernel/cobalt/posix/signal.c b/kernel/cobalt/posix/signal.c
> index 0b43b5fcfa..c2c9c092c4 100644
> --- a/kernel/cobalt/posix/signal.c
> +++ b/kernel/cobalt/posix/signal.c
> @@ -510,7 +510,7 @@ int __cobalt_kill(struct cobalt_thread *thread, int sig, int group) /* nklocked,
>  			sigp->si.si_signo = sig;
>  			sigp->si.si_errno = 0;
>  			sigp->si.si_code = SI_USER;
> -			sigp->si.si_pid = task_pid_nr(current);
> +			sigp->si.si_pid = task_pid_vnr(current);
>  			sigp->si.si_uid = get_current_uuid();
>  			if (cobalt_signal_send(thread, sigp, group) <= 0)
>  				cobalt_signal_free(sigp);
> @@ -525,8 +525,9 @@ int __cobalt_kill(struct cobalt_thread *thread, int sig, int group) /* nklocked,
>  	return ret;
>  }
>  
> -COBALT_SYSCALL(kill, conforming, (pid_t pid, int sig))
> +COBALT_SYSCALL(kill, conforming, (pid_t vpid, int sig))
>  {
> +	pid_t pid = cobalt_vpid2pid_nr(vpid);
>  	struct cobalt_thread *thread;
>  	int ret;
>  	spl_t s;
> @@ -544,8 +545,9 @@ COBALT_SYSCALL(kill, conforming, (pid_t pid, int sig))
>  	return ret;
>  }
>  
> -int __cobalt_sigqueue(pid_t pid, int sig, const union sigval *value)
> +int __cobalt_sigqueue(pid_t vpid, int sig, const union sigval *value)
>  {
> +	pid_t pid = cobalt_vpid2pid_nr(vpid);
>  	struct cobalt_sigpending *sigp;
>  	struct cobalt_thread *thread;
>  	int ret = 0;
> @@ -569,7 +571,7 @@ int __cobalt_sigqueue(pid_t pid, int sig, const union sigval *value)
>  			sigp->si.si_signo = sig;
>  			sigp->si.si_errno = 0;
>  			sigp->si.si_code = SI_QUEUE;
> -			sigp->si.si_pid = task_pid_nr(current);
> +			sigp->si.si_pid = task_pid_vnr(current);
>  			sigp->si.si_uid = get_current_uuid();
>  			sigp->si.si_value = *value;
>  			if (cobalt_signal_send(thread, sigp, 1) <= 0)
> diff --git a/kernel/cobalt/posix/thread.c b/kernel/cobalt/posix/thread.c
> index cdeb66d4f3..2f3ea1dec4 100644
> --- a/kernel/cobalt/posix/thread.c
> +++ b/kernel/cobalt/posix/thread.c
> @@ -624,7 +624,7 @@ int __cobalt_thread_create(unsigned long pth, int policy,
>  		return ret;
>  	}
>  
> -	if (!thread_hash(&hkey, thread, task_pid_vnr(p))) {
> +	if (!thread_hash(&hkey, thread, task_pid_nr(p))) {
>  		ret = -EAGAIN;
>  		goto fail;
>  	}
> @@ -682,7 +682,7 @@ cobalt_thread_shadow(struct cobalt_local_hkey *hkey,
>  		return ERR_PTR(ret);
>  	}
>  
> -	if (!thread_hash(hkey, thread, task_pid_vnr(current))) {
> +	if (!thread_hash(hkey, thread, task_pid_nr(current))) {
>  		ret = -EAGAIN;
>  		goto fail;
>  	}
> @@ -819,7 +819,7 @@ COBALT_SYSCALL(thread_getpid, current, (unsigned long pth))
>  	if (thread == NULL)
>  		pid = -ESRCH;
>  	else
> -		pid = xnthread_host_pid(&thread->threadbase);
> +		pid = xnthread_host_vpid(&thread->threadbase);
>  
>  	xnlock_put_irqrestore(&nklock, s);
>  
> @@ -827,7 +827,7 @@ COBALT_SYSCALL(thread_getpid, current, (unsigned long pth))
>  }
>  
>  COBALT_SYSCALL(thread_getstat, current,
> -	       (pid_t pid, struct cobalt_threadstat __user *u_stat))
> +	       (pid_t vpid, struct cobalt_threadstat __user *u_stat))
>  {
>  	struct cobalt_threadstat stat;
>  	struct cobalt_thread *p;
> @@ -835,14 +835,16 @@ COBALT_SYSCALL(thread_getstat, current,
>  	xnticks_t xtime;
>  	spl_t s;
>  
> -	trace_cobalt_pthread_stat(pid);
> +	trace_cobalt_pthread_stat(vpid);
>  
> -	if (pid == 0) {
> +	if (vpid == 0) {
>  		thread = xnthread_current();
>  		if (thread == NULL)
>  			return -EPERM;
>  		xnlock_get_irqsave(&nklock, s);
>  	} else {
> +		pid_t pid = cobalt_vpid2pid_nr(vpid);
> +
>  		xnlock_get_irqsave(&nklock, s);
>  		p = cobalt_thread_find(pid);
>  		if (p == NULL) {
> diff --git a/kernel/cobalt/thread.c b/kernel/cobalt/thread.c
> index 2c1ec6d3a4..9a97213fbe 100644
> --- a/kernel/cobalt/thread.c
> +++ b/kernel/cobalt/thread.c
> @@ -388,6 +388,16 @@ pid_t xnthread_host_pid(struct xnthread *thread)
>  	return task_pid_nr(xnthread_host_task(thread));
>  }
>  
> +pid_t xnthread_host_vpid(struct xnthread *thread)
> +{
> +	if (xnthread_test_state(thread, XNROOT))
> +		return 0;
> +	if (!xnthread_host_task(thread))
> +		return -1;
> +
> +	return task_pid_vnr(xnthread_host_task(thread));
> +}
> +
>  int xnthread_set_clock(struct xnthread *thread, struct xnclock *newclock)
>  {
>  	spl_t s;
> diff --git a/kernel/cobalt/trace/cobalt-posix.h b/kernel/cobalt/trace/cobalt-posix.h
> index 1d623069df..d66053da8d 100644
> --- a/kernel/cobalt/trace/cobalt-posix.h
> +++ b/kernel/cobalt/trace/cobalt-posix.h
> @@ -246,7 +246,7 @@ DECLARE_EVENT_CLASS(cobalt_posix_scheduler,
>  		memcpy(__get_dynamic_array(param_ex), param_ex, sizeof(*param_ex));
>  	),
>  
> -	TP_printk("pid=%d policy=%s param={ %s }",
> +	TP_printk("vpid=%d policy=%s param={ %s }",
>  		  __entry->pid,
>  		  cobalt_print_sched_policy(__entry->policy),
>  		  __parse_sched_params(__entry->policy,
> @@ -363,7 +363,7 @@ DECLARE_EVENT_CLASS(cobalt_posix_pid,
>  	TP_fast_assign(
>  		__entry->pid = pid;
>  	),
> -	TP_printk("pid=%d", __entry->pid)
> +	TP_printk("vpid=%d", __entry->pid)
>  );
>  
>  DEFINE_EVENT(cobalt_posix_pid, cobalt_pthread_stat,
> 

Ping - did this resolve your issues?

Jan

-- 
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux

RE: [PATCH v2] cobalt: Sort out virtual vs. real pids

[MONTET Julien]

Hi,

I tested all of your patches last week, and it did not change anything.
Compiling the Xenomai libraries directly on Docker didn't solve the issue.

The Xenomai timer seems to work, I can loop on it and print the time (but it was also working before).

Unfortunately I am still stuck on rt_task_wait_period(...).

In any case, I will keep you informed if I achieve to implement this or find my issue.
Do not hesitate to suggest debugging tools/methods, I will be pleased to give you feedback on the results.

Regards,

Julien


On 13.07.21 11:46, Jan Kiszka via Xenomai wrote:
> From: Jan Kiszka <jan.kiszka@siemens.com>
>
> Make sure that we consider all pids taken from or sent to userspace via
> syscalls as virtual. That means converting them to global pids before
> processing them or converting them back to virtual pids in the caller's
> namespace before reporting them. We also need to switch thread hashing
> from vpids to real pids.
>
> Not converted is the procfs interface as this one continues to provide
> only a global view on cobalt objects and associated pids.
>
> A few syscall tracepoints that report the vpid as passed down from
> userspace get adjusted in their output so that it is clear that no
> global pid is shown.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>
> Changes in v2:
>  - fix thread hashing
>  - switch back to global pids in relax tracing
>
>  include/cobalt/kernel/thread.h     |  2 ++
>  kernel/cobalt/posix/event.c        |  2 +-
>  kernel/cobalt/posix/mqueue.c       |  2 +-
>  kernel/cobalt/posix/process.c      | 14 ++++++++++++++
>  kernel/cobalt/posix/process.h      |  2 ++
>  kernel/cobalt/posix/sched.c        | 10 ++++++----
>  kernel/cobalt/posix/sem.c          |  2 +-
>  kernel/cobalt/posix/signal.c       | 10 ++++++----
>  kernel/cobalt/posix/thread.c       | 14 ++++++++------
>  kernel/cobalt/thread.c             | 10 ++++++++++
>  kernel/cobalt/trace/cobalt-posix.h |  4 ++--
>  11 files changed, 53 insertions(+), 19 deletions(-)
>
> diff --git a/include/cobalt/kernel/thread.h b/include/cobalt/kernel/thread.h
> index b79cb84296..4c8a0b9f2a 100644
> --- a/include/cobalt/kernel/thread.h
> +++ b/include/cobalt/kernel/thread.h
> @@ -450,6 +450,8 @@ char *xnthread_format_status(unsigned long status,
>
>  pid_t xnthread_host_pid(struct xnthread *thread);
>
> +pid_t xnthread_host_vpid(struct xnthread *thread);
> +
>  int xnthread_set_clock(struct xnthread *thread,
>                       struct xnclock *newclock);
>
> diff --git a/kernel/cobalt/posix/event.c b/kernel/cobalt/posix/event.c
> index 3712154f53..5871106301 100644
> --- a/kernel/cobalt/posix/event.c
> +++ b/kernel/cobalt/posix/event.c
> @@ -352,7 +352,7 @@ COBALT_SYSCALL(event_inquire, current,
>                xnsynch_for_each_sleeper(thread, &event->synch) {
>                        if (nrwait >= nrpids)
>                                break;
> -                     t[nrwait++] = xnthread_host_pid(thread);
> +                     t[nrwait++] = xnthread_host_vpid(thread);
>                }
>        }
>
> diff --git a/kernel/cobalt/posix/mqueue.c b/kernel/cobalt/posix/mqueue.c
> index dd8acd55b0..fcde87a077 100644
> --- a/kernel/cobalt/posix/mqueue.c
> +++ b/kernel/cobalt/posix/mqueue.c
> @@ -720,7 +720,7 @@ mq_notify(struct cobalt_mqd *mqd, unsigned index, const struct sigevent *evp)
>                 * receiver's namespaces. We pass the receiver's creds
>                 * into the init namespace instead.
>                 */
> -             mq->si.si_pid = task_pid_nr(current);
> +             mq->si.si_pid = task_pid_vnr(current);
>                mq->si.si_uid = get_current_uuid();
>        }
>
> diff --git a/kernel/cobalt/posix/process.c b/kernel/cobalt/posix/process.c
> index 1f059ad830..98b7df33fb 100644
> --- a/kernel/cobalt/posix/process.c
> +++ b/kernel/cobalt/posix/process.c
> @@ -975,6 +975,20 @@ int cobalt_handle_cleanup_event(struct mm_struct *mm)
>        return KEVENT_PROPAGATE;
>  }
>
> +pid_t cobalt_vpid2pid_nr(pid_t vpid)
> +{
> +     struct pid *pid;
> +     pid_t nr = -1;
> +
> +     rcu_read_lock();
> +     pid = find_vpid(vpid);
> +     if (pid)
> +             nr = pid_nr(pid);
> +     rcu_read_unlock();
> +
> +     return nr;
> +}
> +
>  static int attach_process(struct cobalt_process *process)
>  {
>        struct cobalt_ppd *p = &process->sys_ppd;
> diff --git a/kernel/cobalt/posix/process.h b/kernel/cobalt/posix/process.h
> index 279707a680..46dff43b7a 100644
> --- a/kernel/cobalt/posix/process.h
> +++ b/kernel/cobalt/posix/process.h
> @@ -175,4 +175,6 @@ int cobalt_handle_cleanup_event(struct mm_struct *mm);
>
>  int cobalt_handle_user_return(struct task_struct *task);
>
> +pid_t cobalt_vpid2pid_nr(pid_t vpid);
> +
>  #endif /* !_COBALT_POSIX_PROCESS_H */
> diff --git a/kernel/cobalt/posix/sched.c b/kernel/cobalt/posix/sched.c
> index 4fd9c2b46e..26259fbd3f 100644
> --- a/kernel/cobalt/posix/sched.c
> +++ b/kernel/cobalt/posix/sched.c
> @@ -736,7 +736,7 @@ COBALT_SYSCALL(sched_weightprio, current,
>        return __cobalt_sched_weightprio(policy, &param_ex);
>  }
>
> -int cobalt_sched_setscheduler_ex(pid_t pid,
> +int cobalt_sched_setscheduler_ex(pid_t vpid,
>                                 int policy,
>                                 const struct sched_param_ex *param_ex,
>                                 __u32 __user *u_winoff,
> @@ -747,9 +747,11 @@ int cobalt_sched_setscheduler_ex(pid_t pid,
>        int ret, promoted = 0;
>        spl_t s;
>
> -     trace_cobalt_sched_setscheduler(pid, policy, param_ex);
> +     trace_cobalt_sched_setscheduler(vpid, policy, param_ex);
> +
> +     if (vpid) {
> +             pid_t pid = cobalt_vpid2pid_nr(vpid);
>
> -     if (pid) {
>                xnlock_get_irqsave(&nklock, s);
>                thread = cobalt_thread_find(pid);
>                xnlock_put_irqrestore(&nklock, s);
> @@ -757,7 +759,7 @@ int cobalt_sched_setscheduler_ex(pid_t pid,
>                thread = cobalt_current_thread();
>
>        if (thread == NULL) {
> -             if (u_winoff == NULL || pid != task_pid_vnr(current))
> +             if (u_winoff == NULL || vpid != task_pid_vnr(current))
>                        return -ESRCH;
>
>                thread = cobalt_thread_shadow(&hkey, u_winoff);
> diff --git a/kernel/cobalt/posix/sem.c b/kernel/cobalt/posix/sem.c
> index 72b20c78d2..030ce8ffed 100644
> --- a/kernel/cobalt/posix/sem.c
> +++ b/kernel/cobalt/posix/sem.c
> @@ -602,7 +602,7 @@ COBALT_SYSCALL(sem_inquire, current,
>                xnsynch_for_each_sleeper(thread, &sem->synchbase) {
>                        if (nrwait >= nrpids)
>                                break;
> -                     t[nrwait++] = xnthread_host_pid(thread);
> +                     t[nrwait++] = xnthread_host_vpid(thread);
>                }
>        }
>
> diff --git a/kernel/cobalt/posix/signal.c b/kernel/cobalt/posix/signal.c
> index 0b43b5fcfa..c2c9c092c4 100644
> --- a/kernel/cobalt/posix/signal.c
> +++ b/kernel/cobalt/posix/signal.c
> @@ -510,7 +510,7 @@ int __cobalt_kill(struct cobalt_thread *thread, int sig, int group) /* nklocked,
>                        sigp->si.si_signo = sig;
>                        sigp->si.si_errno = 0;
>                        sigp->si.si_code = SI_USER;
> -                     sigp->si.si_pid = task_pid_nr(current);
> +                     sigp->si.si_pid = task_pid_vnr(current);
>                        sigp->si.si_uid = get_current_uuid();
>                        if (cobalt_signal_send(thread, sigp, group) <= 0)
>                                cobalt_signal_free(sigp);
> @@ -525,8 +525,9 @@ int __cobalt_kill(struct cobalt_thread *thread, int sig, int group) /* nklocked,
>        return ret;
>  }
>
> -COBALT_SYSCALL(kill, conforming, (pid_t pid, int sig))
> +COBALT_SYSCALL(kill, conforming, (pid_t vpid, int sig))
>  {
> +     pid_t pid = cobalt_vpid2pid_nr(vpid);
>        struct cobalt_thread *thread;
>        int ret;
>        spl_t s;
> @@ -544,8 +545,9 @@ COBALT_SYSCALL(kill, conforming, (pid_t pid, int sig))
>        return ret;
>  }
>
> -int __cobalt_sigqueue(pid_t pid, int sig, const union sigval *value)
> +int __cobalt_sigqueue(pid_t vpid, int sig, const union sigval *value)
>  {
> +     pid_t pid = cobalt_vpid2pid_nr(vpid);
>        struct cobalt_sigpending *sigp;
>        struct cobalt_thread *thread;
>        int ret = 0;
> @@ -569,7 +571,7 @@ int __cobalt_sigqueue(pid_t pid, int sig, const union sigval *value)
>                        sigp->si.si_signo = sig;
>                        sigp->si.si_errno = 0;
>                        sigp->si.si_code = SI_QUEUE;
> -                     sigp->si.si_pid = task_pid_nr(current);
> +                     sigp->si.si_pid = task_pid_vnr(current);
>                        sigp->si.si_uid = get_current_uuid();
>                        sigp->si.si_value = *value;
>                        if (cobalt_signal_send(thread, sigp, 1) <= 0)
> diff --git a/kernel/cobalt/posix/thread.c b/kernel/cobalt/posix/thread.c
> index cdeb66d4f3..2f3ea1dec4 100644
> --- a/kernel/cobalt/posix/thread.c
> +++ b/kernel/cobalt/posix/thread.c
> @@ -624,7 +624,7 @@ int __cobalt_thread_create(unsigned long pth, int policy,
>                return ret;
>        }
>
> -     if (!thread_hash(&hkey, thread, task_pid_vnr(p))) {
> +     if (!thread_hash(&hkey, thread, task_pid_nr(p))) {
>                ret = -EAGAIN;
>                goto fail;
>        }
> @@ -682,7 +682,7 @@ cobalt_thread_shadow(struct cobalt_local_hkey *hkey,
>                return ERR_PTR(ret);
>        }
>
> -     if (!thread_hash(hkey, thread, task_pid_vnr(current))) {
> +     if (!thread_hash(hkey, thread, task_pid_nr(current))) {
>                ret = -EAGAIN;
>                goto fail;
>        }
> @@ -819,7 +819,7 @@ COBALT_SYSCALL(thread_getpid, current, (unsigned long pth))
>        if (thread == NULL)
>                pid = -ESRCH;
>        else
> -             pid = xnthread_host_pid(&thread->threadbase);
> +             pid = xnthread_host_vpid(&thread->threadbase);
>
>        xnlock_put_irqrestore(&nklock, s);
>
> @@ -827,7 +827,7 @@ COBALT_SYSCALL(thread_getpid, current, (unsigned long pth))
>  }
>
>  COBALT_SYSCALL(thread_getstat, current,
> -            (pid_t pid, struct cobalt_threadstat __user *u_stat))
> +            (pid_t vpid, struct cobalt_threadstat __user *u_stat))
>  {
>        struct cobalt_threadstat stat;
>        struct cobalt_thread *p;
> @@ -835,14 +835,16 @@ COBALT_SYSCALL(thread_getstat, current,
>        xnticks_t xtime;
>        spl_t s;
>
> -     trace_cobalt_pthread_stat(pid);
> +     trace_cobalt_pthread_stat(vpid);
>
> -     if (pid == 0) {
> +     if (vpid == 0) {
>                thread = xnthread_current();
>                if (thread == NULL)
>                        return -EPERM;
>                xnlock_get_irqsave(&nklock, s);
>        } else {
> +             pid_t pid = cobalt_vpid2pid_nr(vpid);
> +
>                xnlock_get_irqsave(&nklock, s);
>                p = cobalt_thread_find(pid);
>                if (p == NULL) {
> diff --git a/kernel/cobalt/thread.c b/kernel/cobalt/thread.c
> index 2c1ec6d3a4..9a97213fbe 100644
> --- a/kernel/cobalt/thread.c
> +++ b/kernel/cobalt/thread.c
> @@ -388,6 +388,16 @@ pid_t xnthread_host_pid(struct xnthread *thread)
>        return task_pid_nr(xnthread_host_task(thread));
>  }
>
> +pid_t xnthread_host_vpid(struct xnthread *thread)
> +{
> +     if (xnthread_test_state(thread, XNROOT))
> +             return 0;
> +     if (!xnthread_host_task(thread))
> +             return -1;
> +
> +     return task_pid_vnr(xnthread_host_task(thread));
> +}
> +
>  int xnthread_set_clock(struct xnthread *thread, struct xnclock *newclock)
>  {
>        spl_t s;
> diff --git a/kernel/cobalt/trace/cobalt-posix.h b/kernel/cobalt/trace/cobalt-posix.h
> index 1d623069df..d66053da8d 100644
> --- a/kernel/cobalt/trace/cobalt-posix.h
> +++ b/kernel/cobalt/trace/cobalt-posix.h
> @@ -246,7 +246,7 @@ DECLARE_EVENT_CLASS(cobalt_posix_scheduler,
>                memcpy(__get_dynamic_array(param_ex), param_ex, sizeof(*param_ex));
>        ),
>
> -     TP_printk("pid=%d policy=%s param={ %s }",
> +     TP_printk("vpid=%d policy=%s param={ %s }",
>                  __entry->pid,
>                  cobalt_print_sched_policy(__entry->policy),
>                  __parse_sched_params(__entry->policy,
> @@ -363,7 +363,7 @@ DECLARE_EVENT_CLASS(cobalt_posix_pid,
>        TP_fast_assign(
>                __entry->pid = pid;
>        ),
> -     TP_printk("pid=%d", __entry->pid)
> +     TP_printk("vpid=%d", __entry->pid)
>  );
>
>  DEFINE_EVENT(cobalt_posix_pid, cobalt_pthread_stat,
>

Ping - did this resolve your issues?

Jan

--
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux

Re: [PATCH v2] cobalt: Sort out virtual vs. real pids

[Jan Kiszka]

On 22.07.21 14:07, MONTET Julien wrote:
> Hi,
> 
> I tested all of your patches last week, and it did not change anything. 
> Compiling the Xenomai libraries directly on Docker didn't solve the issue.
> 
> The Xenomai timer seems to work, I can loop on it and print the time
> (but it was also working before).
> 
> Unfortunately I am still stuck on rt_task_wait_period(...).
> 

That might be becaues I was looking at Marco's test case so as he shared 
his...

I starred at the code again, and this on top may help (and also fix 
signaling by udd):

diff --git a/kernel/cobalt/posix/thread.c b/kernel/cobalt/posix/thread.c
index 2f3ea1dec4..6a79fecb5c 100644
--- a/kernel/cobalt/posix/thread.c
+++ b/kernel/cobalt/posix/thread.c
@@ -176,11 +176,11 @@ struct cobalt_thread *cobalt_thread_find(pid_t pid) /* nklocked, IRQs off */
 }
 EXPORT_SYMBOL_GPL(cobalt_thread_find);
 
-struct cobalt_thread *cobalt_thread_find_local(pid_t pid) /* nklocked, IRQs off */
+struct cobalt_thread *cobalt_thread_find_local(pid_t vpid) /* nklocked, IRQs off */
 {
 	struct cobalt_thread *thread;
 
-	thread = cobalt_thread_find(pid);
+	thread = cobalt_thread_find(cobalt_vpid2pid_nr(vpid));
 	if (thread == NULL || thread->hkey.mm != current->mm)
 		return NULL;
 
diff --git a/kernel/cobalt/posix/thread.h b/kernel/cobalt/posix/thread.h
index 51be372a7a..66e3a88223 100644
--- a/kernel/cobalt/posix/thread.h
+++ b/kernel/cobalt/posix/thread.h
@@ -146,7 +146,7 @@ int cobalt_thread_setschedprio(unsigned long pth,
 
 struct cobalt_thread *cobalt_thread_find(pid_t pid);
 
-struct cobalt_thread *cobalt_thread_find_local(pid_t pid);
+struct cobalt_thread *cobalt_thread_find_local(pid_t vpid);
 
 struct cobalt_thread *cobalt_thread_lookup(unsigned long pth);
 

> In any case, I will keep you informed if I achieve to implement this or
> find my issue.
> Do not hesitate to suggest debugging tools/methods, I will be pleased to
> give you feedback on the results.
> 

BTW, there is the bad news that threadobj_stat() uses /proc to retrieve
thread statistics. That will remain broken over pid namespaces until we
virtualize /proc as well. That affects rt_task_inquire and the registry 
service /wrt tasks.

Jan

-- 
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux

Re: [PATCH v2] cobalt: Sort out virtual vs. real pids

[Jan Kiszka]

On 22.07.21 16:15, Jan Kiszka via Xenomai wrote:
> On 22.07.21 14:07, MONTET Julien wrote:
>> Hi,
>>
>> I tested all of your patches last week, and it did not change anything. 
>> Compiling the Xenomai libraries directly on Docker didn't solve the issue.
>>
>> The Xenomai timer seems to work, I can loop on it and print the time
>> (but it was also working before).
>>
>> Unfortunately I am still stuck on rt_task_wait_period(...).
>>
> 
> That might be becaues I was looking at Marco's test case so as he shared 
> his...
> 
> I starred at the code again, and this on top may help (and also fix 
> signaling by udd):
> 
> diff --git a/kernel/cobalt/posix/thread.c b/kernel/cobalt/posix/thread.c
> index 2f3ea1dec4..6a79fecb5c 100644
> --- a/kernel/cobalt/posix/thread.c
> +++ b/kernel/cobalt/posix/thread.c
> @@ -176,11 +176,11 @@ struct cobalt_thread *cobalt_thread_find(pid_t pid) /* nklocked, IRQs off */
>  }
>  EXPORT_SYMBOL_GPL(cobalt_thread_find);
>  
> -struct cobalt_thread *cobalt_thread_find_local(pid_t pid) /* nklocked, IRQs off */
> +struct cobalt_thread *cobalt_thread_find_local(pid_t vpid) /* nklocked, IRQs off */
>  {
>  	struct cobalt_thread *thread;
>  
> -	thread = cobalt_thread_find(pid);
> +	thread = cobalt_thread_find(cobalt_vpid2pid_nr(vpid));
>  	if (thread == NULL || thread->hkey.mm != current->mm)
>  		return NULL;
>  
> diff --git a/kernel/cobalt/posix/thread.h b/kernel/cobalt/posix/thread.h
> index 51be372a7a..66e3a88223 100644
> --- a/kernel/cobalt/posix/thread.h
> +++ b/kernel/cobalt/posix/thread.h
> @@ -146,7 +146,7 @@ int cobalt_thread_setschedprio(unsigned long pth,
>  
>  struct cobalt_thread *cobalt_thread_find(pid_t pid);
>  
> -struct cobalt_thread *cobalt_thread_find_local(pid_t pid);
> +struct cobalt_thread *cobalt_thread_find_local(pid_t vpid);
>  
>  struct cobalt_thread *cobalt_thread_lookup(unsigned long pth);
>  

Did you have a chance to test this? It's now also part of next. I'll
send out v3 for reference as well.

> 
>> In any case, I will keep you informed if I achieve to implement this or
>> find my issue.
>> Do not hesitate to suggest debugging tools/methods, I will be pleased to
>> give you feedback on the results.
>>
> 
> BTW, there is the bad news that threadobj_stat() uses /proc to retrieve
> thread statistics. That will remain broken over pid namespaces until we
> virtualize /proc as well. That affects rt_task_inquire and the registry 
> service /wrt tasks.
> 

Checked again: threadobj_stat really only uses regular /proc/<pid>/stat,
and that is virtualized by the kernel. However, the registry daemon does
use /proc/xenomai/sched/threads.

Jan

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