Add tfind_user(), for getting a proc* given a user-space TID and

the process* that it should be part of.  Use that in clock_get{time,res}(),
thrkill(), and ptrace().

ok jca@ miod@ mpi@ mvs@

4 files changed, 31 insertions, 22 deletions

diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index e68ffad4126..0eb2df6583a 100644
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_proc.c,v 1.93 2022/12/07 20:08:28 mvs Exp $	*/
+/*	$OpenBSD: kern_proc.c,v 1.94 2023/01/02 23:09:48 guenther Exp $	*/
 /*	$NetBSD: kern_proc.c,v 1.14 1996/02/09 18:59:41 christos Exp $	*/
 
 /*
@@ -200,6 +200,24 @@ tfind(pid_t tid)
 }
 
 /*
+ * Locate a thread by userspace id, from a given process.
+ */
+struct proc *
+tfind_user(pid_t tid, struct process *pr)
+{
+	struct proc *p;
+
+	if (tid < THREAD_PID_OFFSET)
+		return NULL;
+	p = tfind(tid - THREAD_PID_OFFSET);
+
+	/* verify we found a thread in the correct process */
+	if (p != NULL && p->p_p != pr)
+		p = NULL;
+	return p;
+}
+
+/*
  * Locate a process by number
  */
 struct process *
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index f3e2761a78d..38149c19cc8 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_sig.c,v 1.302 2022/12/29 01:36:36 guenther Exp $	*/
+/*	$OpenBSD: kern_sig.c,v 1.303 2023/01/02 23:09:48 guenther Exp $	*/
 /*	$NetBSD: kern_sig.c,v 1.54 1996/04/22 01:38:32 christos Exp $	*/
 
 /*
@@ -640,17 +640,10 @@ sys_thrkill(struct proc *cp, void *v, register_t *retval)
 
 	if (((u_int)signum) >= NSIG)
 		return (EINVAL);
-	if (tid > THREAD_PID_OFFSET) {
-		if ((p = tfind(tid - THREAD_PID_OFFSET)) == NULL)
-			return (ESRCH);
-
-		/* can only kill threads in the same process */
-		if (p->p_p != cp->p_p)
-			return (ESRCH);
-	} else if (tid == 0)
-		p = cp;
-	else
-		return (EINVAL);
+
+	p = tid ? tfind_user(tid, cp->p_p) : cp;
+	if (p == NULL)
+		return (ESRCH);
 
 	/* optionally require the target thread to have the given tcb addr */
 	tcb = SCARG(uap, tcb);
diff --git a/sys/kern/kern_time.c b/sys/kern/kern_time.c
index a86e272a253..1dd0f3aef7f 100644
--- a/sys/kern/kern_time.c
+++ b/sys/kern/kern_time.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_time.c,v 1.160 2022/12/31 16:06:24 cheloha Exp $	*/
+/*	$OpenBSD: kern_time.c,v 1.161 2023/01/02 23:09:48 guenther Exp $	*/
 /*	$NetBSD: kern_time.c,v 1.20 1996/02/18 11:57:06 fvdl Exp $	*/
 
 /*
@@ -139,8 +139,8 @@ clock_gettime(struct proc *p, clockid_t clock_id, struct timespec *tp)
 		/* check for clock from pthread_getcpuclockid() */
 		if (__CLOCK_TYPE(clock_id) == CLOCK_THREAD_CPUTIME_ID) {
 			KERNEL_LOCK();
-			q = tfind(__CLOCK_PTID(clock_id) - THREAD_PID_OFFSET);
-			if (q == NULL || q->p_p != p->p_p)
+			q = tfind_user(__CLOCK_PTID(clock_id), p->p_p);
+			if (q == NULL)
 				error = ESRCH;
 			else
 				*tp = q->p_tu.tu_runtime;
@@ -244,8 +244,8 @@ sys_clock_getres(struct proc *p, void *v, register_t *retval)
 		/* check for clock from pthread_getcpuclockid() */
 		if (__CLOCK_TYPE(clock_id) == CLOCK_THREAD_CPUTIME_ID) {
 			KERNEL_LOCK();
-			q = tfind(__CLOCK_PTID(clock_id) - THREAD_PID_OFFSET);
-			if (q == NULL || q->p_p != p->p_p)
+			q = tfind_user(__CLOCK_PTID(clock_id), p->p_p);
+			if (q == NULL)
 				error = ESRCH;
 			else
 				ts.tv_nsec = 1000000000 / realstathz;
diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c
index de054f0febc..5d0df0cda2e 100644
--- a/sys/kern/sys_process.c
+++ b/sys/kern/sys_process.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sys_process.c,v 1.91 2022/12/21 07:59:02 claudio Exp $	*/
+/*	$OpenBSD: sys_process.c,v 1.92 2023/01/02 23:09:48 guenther Exp $	*/
 /*	$NetBSD: sys_process.c,v 1.55 1996/05/15 06:17:47 tls Exp $	*/
 
 /*-
@@ -556,11 +556,9 @@ ptrace_kstate(struct proc *p, int req, pid_t pid, void *addr)
 		struct proc *t;
 
 		if (req == PT_GET_THREAD_NEXT) {
-			t = tfind(pts->pts_tid - THREAD_PID_OFFSET);
+			t = tfind_user(pts->pts_tid, tr);
 			if (t == NULL || ISSET(t->p_flag, P_WEXIT))
 				return ESRCH;
-			if (t->p_p != tr)
-				return EINVAL;
 			t = TAILQ_NEXT(t, p_thr_link);
 		} else {
 			t = TAILQ_FIRST(&tr->ps_threads);