On Tue, 2022-06-28 at 14:42 -0700, Alison Schofield wrote:
> On Tue, Jun 28, 2022 at 01:04:27PM -0700, Vishal Verma wrote:
> > The conversion of command sizes to unsigned missed a couple of
> > checks
> > against variable size payloads during command validation, which
> > made all
> > variable payload commands unconditionally fail. Add the checks back
> > using
> > the new CXL_VARIABLE_PAYLOAD scheme.
> >
> > Reported-by: Abhi Cs <abhi.cs@xxxxxxxxx>
> > Fixes: 26f89535a5bb ("cxl/mbox: Use type __u32 for mailbox payload
> > sizes")
> > Cc: <stable@xxxxxxxxxxxxxxx>
> > Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
> > Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> > Cc: Alison Schofield <alison.schofield@xxxxxxxxx>
> > Signed-off-by: Vishal Verma <vishal.l.verma@xxxxxxxxx>
>
> with one caveat below...
> Reviewed-by: Alison Schofield <alison.schofield@xxxxxxxxx>
Thanks for the review!
> > ---
> > drivers/cxl/core/mbox.c | 10 ++++++----
> > 1 file changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> > index 40e3ccb2bf3e..d929b89d12a7 100644
> > --- a/drivers/cxl/core/mbox.c
> > +++ b/drivers/cxl/core/mbox.c
> > @@ -355,12 +355,14 @@ static int cxl_to_mem_cmd(struct
> > cxl_mem_command *mem_cmd,
> > return -EBUSY;
> >
> > /* Check the input buffer is the expected size */
> > - if (info->size_in != send_cmd->in.size)
> > - return -ENOMEM;
> > + if (info->size_in != CXL_VARIABLE_PAYLOAD)
> > + if (info->size_in != send_cmd->in.size)
> > + return -ENOMEM;
>
> We can leave it to Dan to arbitrate, but I don't think nested
> if's without brackets follow kernel coding style.
>
> However, Dan didn't like my nested if's with brackets either.
> He'd prefer using &&
Ha funny - I had && originally, but then I spotted nested if () a few
lines above in the same file in cxl_mbox_send_cmd(), and switched to
the same style :)
I'd be happy to change to &&.
>
> >
> > /* Check the output buffer is at least large enough */
> > - if (send_cmd->out.size < info->size_out)
> > - return -ENOMEM;
> > + if (info->size_out != CXL_VARIABLE_PAYLOAD)
> > + if (send_cmd->out.size < info->size_out)
> > + return -ENOMEM;
> >
> > *mem_cmd = (struct cxl_mem_command) {
> > .info = {
> >
> > base-commit: 1985cf58850562e4b960e19d46f0d8f19d6c7cbd
> > --
> > 2.36.1
> >
