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

From: Martin Blumenstingl
Date: Fri Jun 28 2019 - 12:05:47 EST


Hi Colin,

On Fri, Jun 28, 2019 at 10:32 AM Colin Ian King
<colin.king@xxxxxxxxxxxxx> wrote:
>
> On 28/06/2019 05:15, Martin Blumenstingl wrote:
> > 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?
>
> Your fix is good, so I think we should just drop/forget about my fix.
thank you for looking at the situation

as far I understand the -net/-net-next tree all commits are immutable
so if we want to remove your patch we need to send a revert
do you want me to do that (I can do it on Monday) or will you take care of that?


Martin