Re: [PATCH kselftest/test] kunit: Always print actual pointer values in asserts

[shuah]

On 3/25/20 10:33 AM, Brendan Higgins wrote:
> On Tue, Mar 24, 2020 at 8:33 PM David Gow <davidgow@xxxxxxxxxx> wrote:
> > On Tue, Dec 3, 2019 at 3:44 PM Brendan Higgins
> > <brendanhiggins@xxxxxxxxxx> wrote:
> > > On Thu, Nov 21, 2019 at 3:51 PM David Gow <davidgow@xxxxxxxxxx> wrote:
> > > > KUnit assertions and expectations will print the values being tested. If
> > > > these are pointers (e.g., KUNIT_EXPECT_PTR_EQ(test, a, b)), these
> > > > pointers are currently printed with the %pK format specifier, which -- to
> > > > prevent information leaks which may compromise, e.g., ASLR -- are often
> > > > either hashed or replaced with ____ptrval____ or similar, making debugging
> > > > tests difficult.
> > > >
> > > > By replacing %pK with %px as Documentation/core-api/printk-formats.rst
> > > > suggests, we disable this security feature for KUnit assertions and
> > > > expectations, allowing the actual pointer values to be printed. Given
> > > > that KUnit is not intended for use in production kernels, and the
> > > > pointers are only printed on failing tests, this seems like a worthwhile
> > > > tradeoff.
> > >
> > > I agree. However, I also remember that others in the past yelled at me
> > > for assuming that KUnit would not be built into production kernels.
> > >
> > > I feel like +Kees Cook would have a good opinion on this (or will at
> > > least CC the right people).
> >
> > I'm tempted to take the silence as a sign that no-one is upset by
> > this. Otherwise, consider this a gentle reminder to file any
> > objections you may have. :-)
> >
> > Otherwise, I've confirmed that this still applies cleanly to the
> > latest linux-kselftest/kunit branch, so -- assuming there are no
> > last-minute objections -- this ought to be ready to go.
>
> Shuah, can you pick this up for 5.7?

Yes. I will pick this up.

thanks,
-- Shuah