Re: [dpdk-dev] [PATCH] vhost: Fix `struct file' leakage in `eventfd_link'

[Pavel Boldin <pboldin@mirantis.com>]

On Tue, Mar 24, 2015 at 8:28 AM, Xie, Huawei <huawei.xie@intel.com> wrote:

> On 3/23/2015 8:54 PM, Pavel Boldin wrote:
> > Due to increased `struct file's reference counter subsequent call
> > to `filp_close' does not free the `struct file'. Prepend `fput' call
> > to decrease the reference counter.
> >
> > Signed-off-by: Pavel Boldin <pboldin@mirantis.com>
> > ---
> >  lib/librte_vhost/eventfd_link/eventfd_link.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/lib/librte_vhost/eventfd_link/eventfd_link.c
> b/lib/librte_vhost/eventfd_link/eventfd_link.c
> > index 7755dd6..62c45c8 100644
> > --- a/lib/librte_vhost/eventfd_link/eventfd_link.c
> > +++ b/lib/librte_vhost/eventfd_link/eventfd_link.c
> > @@ -117,6 +117,7 @@ eventfd_link_ioctl(struct file *f, unsigned int
> ioctl, unsigned long arg)
> >                * Release the existing eventfd in the source process
> >                */
> >               spin_lock(&files->file_lock);
> > +             fput(file);
> >               filp_close(file, files);
> >               fdt = files_fdtable(files);
> >               fdt->fd[eventfd_copy.source_fd] = NULL;
> Acked-by Huawei Xie <huawei.xie@intel.com>
>
> In future, we should remove the allocation of src eventfd, allocate a
> free fd from kernel, and install it with target fd.
>

Well, I don't think this is correct, because this will put too much job for
the kernel module making it a combiner.

At the moment I propose to accept module refactoring patch to the upstream.

After that the module can be reworked along with the application code. The
reason is I can't work on DPDK since I have no hardware to test application
at so I can't help with patch that touches application code.

Pavel