1 files changed, 18 insertions, 1 deletions

diff --git a/sys/miscfs/procfs/procfs_ctl.c b/sys/miscfs/procfs/procfs_ctl.c
index d96bcb3..72ad575 100644
--- a/sys/miscfs/procfs/procfs_ctl.c
+++ b/sys/miscfs/procfs/procfs_ctl.c
@@ -158,8 +158,12 @@ procfs_control(curp, p, op)
 		break;
 
 	default:
-		if (!TRACE_WAIT_P(curp, p))
+		mtx_enter(&sched_lock, MTX_SPIN);
+		if (!TRACE_WAIT_P(curp, p)) {
+			mtx_exit(&sched_lock, MTX_SPIN);
 			return (EBUSY);
+		}
+		mtx_exit(&sched_lock, MTX_SPIN);
 	}
 
 
@@ -234,20 +238,28 @@ procfs_control(curp, p, op)
 	case PROCFS_CTL_WAIT:
 		error = 0;
 		if (p->p_flag & P_TRACED) {
+			mtx_enter(&sched_lock, MTX_SPIN);
 			while (error == 0 &&
 					(p->p_stat != SSTOP) &&
 					(p->p_flag & P_TRACED) &&
 					(p->p_pptr == curp)) {
+				mtx_exit(&sched_lock, MTX_SPIN);
 				error = tsleep((caddr_t) p,
 						PWAIT|PCATCH, "procfsx", 0);
+				mtx_enter(&sched_lock, MTX_SPIN);
 			}
 			if (error == 0 && !TRACE_WAIT_P(curp, p))
 				error = EBUSY;
+			mtx_exit(&sched_lock, MTX_SPIN);
 		} else {
+			mtx_enter(&sched_lock, MTX_SPIN);
 			while (error == 0 && p->p_stat != SSTOP) {
+				mtx_exit(&sched_lock, MTX_SPIN);
 				error = tsleep((caddr_t) p,
 						PWAIT|PCATCH, "procfs", 0);
+				mtx_enter(&sched_lock, MTX_SPIN);
 			}
+			mtx_exit(&sched_lock, MTX_SPIN);
 		}
 		return (error);
 
@@ -255,8 +267,10 @@ procfs_control(curp, p, op)
 		panic("procfs_control");
 	}
 
+	mtx_enter(&sched_lock, MTX_SPIN);
 	if (p->p_stat == SSTOP)
 		setrunnable(p);
+	mtx_exit(&sched_lock, MTX_SPIN);
 	return (0);
 }
 
@@ -297,13 +311,16 @@ procfs_doctl(curp, p, pfs, uio)
 	} else {
 		nm = vfs_findname(signames, msg, xlen);
 		if (nm) {
+			mtx_enter(&sched_lock, MTX_SPIN);
 			if (TRACE_WAIT_P(curp, p)) {
 				p->p_xstat = nm->nm_val;
 #ifdef FIX_SSTEP
 				FIX_SSTEP(p);
 #endif
 				setrunnable(p);
+				mtx_exit(&sched_lock, MTX_SPIN);
 			} else {
+				mtx_exit(&sched_lock, MTX_SPIN);
 				psignal(p, nm->nm_val);
 			}
 			error = 0;