Move per-thread userland debugging flags into seperated field,

this eliminates some problems of locking, e.g, a thread lock is needed
but can not be used at that time. Only the process lock is needed now
for new field.

4 files changed, 15 insertions, 22 deletions

diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index e956cdf..6ebe032 100644
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -438,7 +438,11 @@ exit1(struct thread *td, int rv)
 		 * since their existence means someone is screwing up.
 		 */
 		if (q->p_flag & P_TRACED) {
+			struct thread *temp;
+
 			q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE);
+			FOREACH_THREAD_IN_PROC(q, temp)
+				temp->td_dbgflags &= ~TDB_SUSPEND;
 			psignal(q, SIGKILL);
 		}
 		PROC_UNLOCK(q);
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index d5d1813..f4cf8ad 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -2342,16 +2342,12 @@ ptracestop(struct thread *td, int sig)
 	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
 	    &p->p_mtx.lock_object, "Stopping for traced signal");
 
-	thread_lock(td);
-	td->td_flags |= TDF_XSIG;
-	thread_unlock(td);
+	td->td_dbgflags |= TDB_XSIG;
 	td->td_xsig = sig;
 	PROC_SLOCK(p);
-	while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) {
+	while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) {
 		if (p->p_flag & P_SINGLE_EXIT) {
-			thread_lock(td);
-			td->td_flags &= ~TDF_XSIG;
-			thread_unlock(td);
+			td->td_dbgflags &= ~TDB_XSIG;
 			PROC_SUNLOCK(p);
 			return (sig);
 		}
@@ -2368,7 +2364,7 @@ stopme:
 		if (!(p->p_flag & P_TRACED)) {
 			break;
 		}
-		if (td->td_flags & TDF_DBSUSPEND) {
+		if (td->td_dbgflags & TDB_SUSPEND) {
 			if (p->p_flag & P_SINGLE_EXIT)
 				break;
 			goto stopme;
diff --git a/sys/kern/kern_thread.c b/sys/kern/kern_thread.c
index bb87696..7298edc 100644
--- a/sys/kern/kern_thread.c
+++ b/sys/kern/kern_thread.c
@@ -563,8 +563,6 @@ thread_single(int mode)
 			if (TD_IS_INHIBITED(td2)) {
 				switch (mode) {
 				case SINGLE_EXIT:
-					if (td->td_flags & TDF_DBSUSPEND)
-						td->td_flags &= ~TDF_DBSUSPEND;
 					if (TD_IS_SUSPENDED(td2))
 						wakeup_swapper |=
 						    thread_unsuspend_one(td2);
@@ -685,7 +683,7 @@ thread_suspend_check(int return_instead)
 	mtx_assert(&Giant, MA_NOTOWNED);
 	PROC_LOCK_ASSERT(p, MA_OWNED);
 	while (P_SHOULDSTOP(p) ||
-	      ((p->p_flag & P_TRACED) && (td->td_flags & TDF_DBSUSPEND))) {
+	      ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_SUSPEND))) {
 		if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) {
 			KASSERT(p->p_singlethread != NULL,
 			    ("singlethread not set"));
diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c
index dbdd30f..ceae8de 100644
--- a/sys/kern/sys_process.c
+++ b/sys/kern/sys_process.c
@@ -700,15 +700,14 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 		break;
 
 	case PT_SUSPEND:
+		td2->td_dbgflags |= TDB_SUSPEND;
 		thread_lock(td2);
-		td2->td_flags |= TDF_DBSUSPEND;
+		td2->td_flags |= TDF_NEEDSUSPCHK;
 		thread_unlock(td2);
 		break;
 
 	case PT_RESUME:
-		thread_lock(td2);
-		td2->td_flags &= ~TDF_DBSUSPEND;
-		thread_unlock(td2);
+		td2->td_dbgflags &= ~TDB_SUSPEND;
 		break;
 
 	case PT_STEP:
@@ -782,17 +781,13 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 		p->p_xthread = NULL;
 		if ((p->p_flag & (P_STOPPED_SIG | P_STOPPED_TRACE)) != 0) {
 			/* deliver or queue signal */
-			thread_lock(td2);
-			td2->td_flags &= ~TDF_XSIG;
-			thread_unlock(td2);
+			td2->td_dbgflags &= ~TDB_XSIG;
 			td2->td_xsig = data;
 
 			if (req == PT_DETACH) {
 				struct thread *td3;
 				FOREACH_THREAD_IN_PROC(p, td3) {
-					thread_lock(td3);
-					td3->td_flags &= ~TDF_DBSUSPEND; 
-					thread_unlock(td3);
+					td3->td_dbgflags &= ~TDB_SUSPEND; 
 				}
 			}
 			/*
@@ -932,7 +927,7 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 		}
 		pl = addr;
 		pl->pl_lwpid = td2->td_tid;
-		if (td2->td_flags & TDF_XSIG)
+		if (td2->td_dbgflags & TDB_XSIG)
 			pl->pl_event = PL_EVENT_SIGNAL;
 		else
 			pl->pl_event = 0;