9os

commit 6e09d19535fdb94f2ed751bee214c6a8dfa7399b
parent 195855ac4daa9ce7119c4eff9ae2f011d6e01df6
Author: Roberto E. Vargas Caballero <roberto.vargas@midokura.com>
Date:   Thu, 17 Nov 2022 07:58:02 +0100

os9: Fix locking around clone()

Clone() calls newtask() that cannot be called with
any task locked.

Diffstat:
M
src/os9/proc.c
 | 
7
++++++-

1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/src/os9/proc.c b/src/os9/proc.c
@@ -349,6 +349,8 @@ clone(Task *parent)
 	if (!initptable(tp) || !newstack(tp))
 		goto err;
 
+	lock(&parent->m);
+
 	tp->ppid = parent->pid;
 
 	tp->entry = parent->entry;
@@ -387,6 +389,8 @@ clone(Task *parent)
 	if (tp->fds)
 		incref(&parent->fds->ref);
 
+	unlock(&parent->m);
+
 	return tp;
 
 err:
@@ -415,7 +419,6 @@ rfork(int flags)
 	fds = NULL;
 	data = NULL;
 
-	lock(&proc->m);
 	if ((flags & RFPROC) != 0) {
 		if ((tp = clone(proc)) == NULL)
 			return -1;
@@ -426,6 +429,8 @@ rfork(int flags)
 		if (savectx(tp) == 0)
 			return 0;
 	}
+
+	lock(&proc->m);
 	if ((flags & RFCNAMEG) != 0) {
 		if ((ns = newspace(NULL)) == NULL)
 			goto err;