cobalt/kernel/thread: add cobalt_thread_getpid service

This service returns the per-task kernel pid of a local pthread.

include/cobalt/uapi/syscall.h

@@ -23,7 +23,7 @@
 #define COBALT_BINDING_MAGIC            0x50534531
 
 #define sc_cobalt_thread_create         0
-/* 1 unimplemented */
+#define sc_cobalt_thread_getpid         1
 #define sc_cobalt_sched_weightprio      2
 #define sc_cobalt_sched_yield           3
 /* 4-5 unimplemented */

kernel/cobalt/posix/syscall.c

@@ -88,6 +88,7 @@ static int cobalt_syscall_ni(void)
 static struct xnsyscall cobalt_syscalls[] = {
 	[0 ... __NR_COBALT_SYSCALLS-1] = SKINCALL_NI,
 	SKINCALL_DEF(sc_cobalt_thread_create, cobalt_thread_create, init),
+	SKINCALL_DEF(sc_cobalt_thread_getpid, cobalt_thread_pid, current),
 	SKINCALL_DEF(sc_cobalt_thread_setschedparam_ex, cobalt_thread_setschedparam_ex, conforming),
 	SKINCALL_DEF(sc_cobalt_thread_getschedparam_ex, cobalt_thread_getschedparam_ex, current),
 	SKINCALL_DEF(sc_cobalt_sched_weightprio, cobalt_sched_weighted_prio, current),

kernel/cobalt/posix/thread.c

@@ -705,6 +705,30 @@ int cobalt_thread_join(unsigned long pth)
 	return xnthread_join(&thread->threadbase, false);
 }
 
+pid_t cobalt_thread_pid(unsigned long pth)
+{
+	struct cobalt_local_hkey hkey;
+	struct cobalt_thread *thread;
+	pid_t pid;
+	spl_t s;
+
+	trace_cobalt_pthread_pid(pth);
+
+	xnlock_get_irqsave(&nklock, s);
+
+	hkey.u_pth = pth;
+	hkey.mm = current->mm;
+	thread = thread_lookup(&hkey);
+	if (thread == NULL)
+		pid = -ESRCH;
+	else
+		pid = xnthread_host_pid(&thread->threadbase);
+
+	xnlock_put_irqrestore(&nklock, s);
+
+	return pid;
+}
+
 int cobalt_thread_stat(pid_t pid,
 		       struct cobalt_threadstat __user *u_stat)
 {

kernel/cobalt/posix/thread.h

@@ -128,7 +128,7 @@ struct cobalt_thread *cobalt_thread_find_local(pid_t pid);
 
 struct cobalt_thread *cobalt_thread_lookup(unsigned long pth);
 
-int cobalt_thread_create(unsigned long tid, int policy,
+int cobalt_thread_create(unsigned long pth, int policy,
 			 struct sched_param_ex __user *u_param,
 			 int shifted_muxid,
 			 unsigned long __user *u_window_offset);
@@ -140,24 +140,24 @@ cobalt_thread_shadow(struct task_struct *p,
 
 int cobalt_thread_setmode_np(int clrmask, int setmask, int __user *u_mode_r);
 
-int cobalt_thread_setname_np(unsigned long tid, const char __user *u_name);
+int cobalt_thread_setname_np(unsigned long pth, const char __user *u_name);
 
-int cobalt_thread_probe_np(pid_t h_tid);
+int cobalt_thread_kill(unsigned long pth, int sig);
 
-int cobalt_thread_kill(unsigned long tid, int sig);
+int cobalt_thread_join(unsigned long pth);
 
-int cobalt_thread_join(unsigned long tid);
+pid_t cobalt_thread_pid(unsigned long pth);
 
 int cobalt_thread_stat(pid_t pid,
 		       struct cobalt_threadstat __user *u_stat);
 
-int cobalt_thread_setschedparam_ex(unsigned long tid,
+int cobalt_thread_setschedparam_ex(unsigned long pth,
 				   int policy,
 				   const struct sched_param_ex __user *u_param,
 				   unsigned long __user *u_window_offset,
 				   int __user *u_promoted);
 
-int cobalt_thread_getschedparam_ex(unsigned long tid,
+int cobalt_thread_getschedparam_ex(unsigned long pth,
 				   int __user *u_policy,
 				   struct sched_param_ex __user *u_param);
 

kernel/cobalt/trace/cobalt-posix.h

@@ -177,11 +177,6 @@ DECLARE_EVENT_CLASS(cobalt_posix_pid,
 	TP_printk("pid=%d", __entry->pid)
 );
 
-DEFINE_EVENT(cobalt_posix_pid, cobalt_pthread_probe,
-	TP_PROTO(pid_t pid),
-	TP_ARGS(pid)
-);
-
 DEFINE_EVENT(cobalt_posix_pid, cobalt_pthread_stat,
 	TP_PROTO(pid_t pid),
 	TP_ARGS(pid)
@@ -213,6 +208,18 @@ TRACE_EVENT(cobalt_pthread_join,
 	TP_printk("pth=%p", (void *)__entry->pth)
 );
 
+TRACE_EVENT(cobalt_pthread_pid,
+	TP_PROTO(unsigned long pth),
+	TP_ARGS(pth),
+	TP_STRUCT__entry(
+		__field(unsigned long, pth)
+	),
+	TP_fast_assign(
+		__entry->pth = pth;
+	),
+	TP_printk("pth=%p", (void *)__entry->pth)
+);
+
 TRACE_EVENT(cobalt_pthread_extend,
 	TP_PROTO(unsigned long pth, const char *name),
 	TP_ARGS(pth, name),