On Thu, Dec 07, 2023 at 05:34:10PM +0100, Joel Granados wrote:
> > @@ -58,6 +255,8 @@ static void hw_pagetable_fault_free(struct
> > hw_pgtable_fault *fault)
> > WARN_ON(!list_empty(&fault->deliver));
> > WARN_ON(!list_empty(&fault->response));
> >
> > + fput(fault->fault_file);
> > + put_unused_fd(fault->fault_fd);
> I have resolved this in a naive way by just not calling the
> put_unused_fd function.
That is correct.
put_unused_fd() should only be called on error paths prior to the
syscall return.
The design of a FD must follow this pattern
syscall():
fdno = get_unused_fd_flags(O_CLOEXEC);
filep = [..]
// syscall MUST succeed after this statement:
fd_install(fdno, filep);
return 0;
err:
put_unused_fd(fdno)
return -ERRNO
Also the refcounting looks a little strange, the filep reference is
consumed by fd_install, so what is that fput pairing with in fault_free?
Jason
