On 17/03/20(Tue) 04:02, Philip Guenther wrote: > On Tue, Mar 17, 2020 at 1:07 AM Martin Pieuchot <m...@openbsd.org> wrote: > [...] > > @@ -663,8 +668,6 @@ ktrwriteraw(struct proc *curp, struct vn > > LIST_FOREACH(pr, &allprocess, ps_list) > > if (pr->ps_tracevp == vp && pr->ps_tracecred == cred) > > ktrcleartrace(pr); > > - > > - vput(vp); > > return (error); > > } > > > > This looks unsafe to me: isn't ktrcleartrace() only safe if the caller > holds a reference to the vnode? Once ktrcleartrace() clears the reference > from the current thread's process and it goes on the freelist, can't the > vnode vp points to be invalidated and reused?
As long as a process holds a reference to the vnode, via `ps_tracevp', it wont be recycle. Only the last call of ktrcleartrace() will release the vnode via vrele(9).
