Re: [PATCH] net: stmmac: add sanity check to device_property_read_u32_array call

From: Martin Blumenstingl
Date: Fri Jun 28 2019 - 00:15:13 EST


On Tue, Jun 25, 2019 at 9:58 AM Colin Ian King <colin.king@xxxxxxxxxxxxx> wrote:
>
> On 25/06/2019 05:44, Martin Blumenstingl wrote:
> > Hi Colin,
> >
> > On Thu, Jun 20, 2019 at 3:34 AM Martin Blumenstingl
> > <martin.blumenstingl@xxxxxxxxxxxxxx> wrote:
> >>
> >> Hi Colin,
> >>
> >> On Wed, Jun 19, 2019 at 8:55 AM Colin Ian King <colin.king@xxxxxxxxxxxxx> wrote:
> >>>
> >>> On 19/06/2019 06:13, Martin Blumenstingl wrote:
> >>>> Hi Colin,
> >>>>
> >>>>> Currently the call to device_property_read_u32_array is not error checked
> >>>>> leading to potential garbage values in the delays array that are then used
> >>>>> in msleep delays. Add a sanity check to the property fetching.
> >>>>>
> >>>>> Addresses-Coverity: ("Uninitialized scalar variable")
> >>>>> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> >>>> I have also sent a patch [0] to fix initialize the array.
> >>>> can you please look at my patch so we can work out which one to use?
> >>>>
> >>>> my concern is that the "snps,reset-delays-us" property is optional,
> >>>> the current dt-bindings documentation states that it's a required
> >>>> property. in reality it isn't, there are boards (two examples are
> >>>> mentioned in my patch: [0]) without it.
> >>>>
> >>>> so I believe that the resulting behavior has to be:
> >>>> 1. don't delay if this property is missing (instead of delaying for
> >>>> <garbage value> ms)
> >>>> 2. don't error out if this property is missing
> >>>>
> >>>> your patch covers #1, can you please check whether #2 is also covered?
> >>>> I tested case #2 when submitting my patch and it worked fine (even
> >>>> though I could not reproduce the garbage values which are being read
> >>>> on some boards)
> > in the meantime I have tested your patch.
> > when I don't set the "snps,reset-delays-us" property then I get the
> > following error:
> > invalid property snps,reset-delays-us
> >
> > my patch has landed in the meantime: [0]
> > how should we proceed with your patch?
>
> I'm out of the office today. I'll get back to you on this tomorrow.
gentle ping
(I will be away for the weekend but I can reply on Monday)