Use the proc lock to protect p_singlethread and a P_WEXIT test. This

fixes a couple of potential KSE panics on non-i386 arch's that weren't
holding the proc lock when calling thread_exit().

7 files changed, 15 insertions, 11 deletions

diff --git a/sys/alpha/alpha/trap.c b/sys/alpha/alpha/trap.c
index f52152a..e5975e2 100644
--- a/sys/alpha/alpha/trap.c
+++ b/sys/alpha/alpha/trap.c
@@ -298,12 +298,13 @@ trap(a0, a1, a2, entry, framep)
 		td->td_frame = framep;
 		if (td->td_ucred != p->p_ucred)
 			cred_update_thread(td);
+		PROC_LOCK(p);
 		if ((p->p_flag & P_WEXIT) && (p->p_singlethread != td)) {
-			PROC_LOCK(p);
 			mtx_lock_spin(&sched_lock);
 			thread_exit();
 			/* NOTREACHED */
 		}
+		PROC_UNLOCK(p);
 	} else {
 		sticks = 0;		/* XXX bogus -Wuninitialized warning */
 		KASSERT(cold || td->td_ucred != NULL,
diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
index 0eb46ee..c0784fa 100644
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -271,14 +271,14 @@ trap(frame)
 		/*
 		 * First check that we shouldn't just abort.
 		 * But check if we are the single thread first!
-		 * XXX p_singlethread not locked, but should be safe.
 		 */
+		PROC_LOCK(p);
 		if ((p->p_flag & P_WEXIT) && (p->p_singlethread != td)) {
-			PROC_LOCK(p);
 			mtx_lock_spin(&sched_lock);
 			thread_exit();
 			/* NOTREACHED */
 		}
+		PROC_UNLOCK(p);
 
 		switch (type) {
 		case T_PRIVINFLT:	/* privileged instruction fault */
diff --git a/sys/i386/i386/trap.c b/sys/i386/i386/trap.c
index 0eb46ee..c0784fa 100644
--- a/sys/i386/i386/trap.c
+++ b/sys/i386/i386/trap.c
@@ -271,14 +271,14 @@ trap(frame)
 		/*
 		 * First check that we shouldn't just abort.
 		 * But check if we are the single thread first!
-		 * XXX p_singlethread not locked, but should be safe.
 		 */
+		PROC_LOCK(p);
 		if ((p->p_flag & P_WEXIT) && (p->p_singlethread != td)) {
-			PROC_LOCK(p);
 			mtx_lock_spin(&sched_lock);
 			thread_exit();
 			/* NOTREACHED */
 		}
+		PROC_UNLOCK(p);
 
 		switch (type) {
 		case T_PRIVINFLT:	/* privileged instruction fault */
diff --git a/sys/ia64/ia64/trap.c b/sys/ia64/ia64/trap.c
index 3fdf9a6..0e86100 100644
--- a/sys/ia64/ia64/trap.c
+++ b/sys/ia64/ia64/trap.c
@@ -334,11 +334,13 @@ trap(int vector, int imm, struct trapframe *framep)
 		td->td_frame = framep;
 		if (td->td_ucred != p->p_ucred)
 			cred_update_thread(td);
+		PROC_LOCK(p);
 		if ((p->p_flag & P_WEXIT) && (p->p_singlethread != td)) {
 			mtx_lock_spin(&sched_lock);
-			thread_exit(); /* XXXKSE need proc lock? */
+			thread_exit();
 			/* NOTREACHED */
 		}
+		PROC_UNLOCK(p);
 	} else {
 		sticks = 0;		/* XXX bogus -Wuninitialized warning */
 		KASSERT(cold || td->td_ucred != NULL,
diff --git a/sys/kern/kern_kse.c b/sys/kern/kern_kse.c
index 5f03369..cb91577 100644
--- a/sys/kern/kern_kse.c
+++ b/sys/kern/kern_kse.c
@@ -1544,15 +1544,15 @@ thread_user_enter(struct proc *p, struct thread *td)
 	/*
 	 * First check that we shouldn't just abort.
 	 * But check if we are the single thread first!
-	 * XXX p_singlethread not locked, but should be safe.
 	 */
+	PROC_LOCK(p);
 	if ((p->p_flag & P_SINGLE_EXIT) && (p->p_singlethread != td)) {
-		PROC_LOCK(p);
 		mtx_lock_spin(&sched_lock);
 		thread_stopped(p);
 		thread_exit();
 		/* NOTREACHED */
 	}
+	PROC_UNLOCK(p);
 
 	/*
 	 * If we are doing a syscall in a KSE environment,
diff --git a/sys/kern/kern_thread.c b/sys/kern/kern_thread.c
index 5f03369..cb91577 100644
--- a/sys/kern/kern_thread.c
+++ b/sys/kern/kern_thread.c
@@ -1544,15 +1544,15 @@ thread_user_enter(struct proc *p, struct thread *td)
 	/*
 	 * First check that we shouldn't just abort.
 	 * But check if we are the single thread first!
-	 * XXX p_singlethread not locked, but should be safe.
 	 */
+	PROC_LOCK(p);
 	if ((p->p_flag & P_SINGLE_EXIT) && (p->p_singlethread != td)) {
-		PROC_LOCK(p);
 		mtx_lock_spin(&sched_lock);
 		thread_stopped(p);
 		thread_exit();
 		/* NOTREACHED */
 	}
+	PROC_UNLOCK(p);
 
 	/*
 	 * If we are doing a syscall in a KSE environment,
diff --git a/sys/sparc64/sparc64/trap.c b/sys/sparc64/sparc64/trap.c
index c743162..2df2c58 100644
--- a/sys/sparc64/sparc64/trap.c
+++ b/sys/sparc64/sparc64/trap.c
@@ -245,12 +245,13 @@ trap(struct trapframe *tf)
 		td->td_frame = tf;
 		if (td->td_ucred != p->p_ucred)
 			cred_update_thread(td);
+		PROC_LOCK(p);
 		if ((p->p_flag & P_WEXIT) && (p->p_singlethread != td)) {
-			PROC_LOCK(p);
 			mtx_lock_spin(&sched_lock);
 			thread_exit();
 			/* NOTREACHED */
 		}
+		PROC_UNLOCK(p);
 
 		switch (tf->tf_type) {
 		case T_DATA_MISS: