ktrwriteraw & vget

[Martin Pieuchot]

vget(9) might fail, stop right away if that happens.

CID 1453020 Unchecked return value.

ok?

Index: kern//kern_ktrace.c
===================================================================
RCS file: /cvs/src/sys/kern/kern_ktrace.c,v
retrieving revision 1.100
diff -u -p -r1.100 kern_ktrace.c
--- kern//kern_ktrace.c 6 Oct 2019 16:24:14 -0000       1.100
+++ kern//kern_ktrace.c 16 Mar 2020 12:58:19 -0000
@@ -649,7 +649,9 @@ ktrwriteraw(struct proc *curp, struct vn
                        auio.uio_iovcnt++;
                auio.uio_resid += kth->ktr_len;
        }
-       vget(vp, LK_EXCLUSIVE | LK_RETRY);
+       error = vget(vp, LK_EXCLUSIVE | LK_RETRY);
+       if (error)
+               return (error);
        error = VOP_WRITE(vp, &auio, IO_UNIT|IO_APPEND, cred);
        if (!error) {
                vput(vp);