Re: [PATCH v3 2/2] usercopy: Convert test_user_copy to KUnit test

[Kees Cook <kees@kernel.org>]

On Fri, Jun 14, 2024 at 09:50:05AM -0600, Shuah Khan wrote:
> On 6/12/24 13:59, Kees Cook wrote:
> > Convert the runtime tests of hardened usercopy to standard KUnit tests.
> > 
> > Additionally disable usercopy_test_invalid() for systems with separate
> > address spaces (or no MMU) since it's not sensible to test for address
> > confusion there (e.g. m68k).
> > 
> > Co-developed-by: Vitor Massaru Iha <vitor@massaru.org>
> > Signed-off-by: Vitor Massaru Iha <vitor@massaru.org>
> > Link: https://lore.kernel.org/r/20200721174654.72132-1-vitor@massaru.org
> > Tested-by: Ivan Orlov <ivan.orlov0322@gmail.com>
> > Reviewed-by: David Gow <davidgow@google.com>
> > Signed-off-by: Kees Cook <kees@kernel.org>
> > ---
> >   MAINTAINERS                                |   1 +
> >   lib/Kconfig.debug                          |  21 +-
> >   lib/Makefile                               |   2 +-
> >   lib/{test_user_copy.c => usercopy_kunit.c} | 282 ++++++++++-----------
> >   4 files changed, 151 insertions(+), 155 deletions(-)
> >   rename lib/{test_user_copy.c => usercopy_kunit.c} (46%)
> > 
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 8754ac2c259d..0cd171ec6010 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -11962,6 +11962,7 @@ F:	arch/*/configs/hardening.config
> >   F:	include/linux/overflow.h
> >   F:	include/linux/randomize_kstack.h
> >   F:	kernel/configs/hardening.config
> > +F:	lib/usercopy_kunit.c
> >   F:	mm/usercopy.c
> >   K:	\b(add|choose)_random_kstack_offset\b
> >   K:	\b__check_(object_size|heap_object)\b
> > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> > index 59b6765d86b8..561e346f5cb0 100644
> > --- a/lib/Kconfig.debug
> > +++ b/lib/Kconfig.debug
> > @@ -2505,18 +2505,6 @@ config TEST_VMALLOC
> >   	  If unsure, say N.
> > -config TEST_USER_COPY
> > -	tristate "Test user/kernel boundary protections"
> > -	depends on m
> > -	help
> > -	  This builds the "test_user_copy" module that runs sanity checks
> > -	  on the copy_to/from_user infrastructure, making sure basic
> > -	  user/kernel boundary testing is working. If it fails to load,
> > -	  a regression has been detected in the user/kernel memory boundary
> > -	  protections.
> > -
> > -	  If unsure, say N.
> > -
> >   config TEST_BPF
> >   	tristate "Test BPF filter functionality"
> >   	depends on m && NET
> > @@ -2814,6 +2802,15 @@ config SIPHASH_KUNIT_TEST
> >   	  This is intended to help people writing architecture-specific
> >   	  optimized versions.  If unsure, say N.
> > +config USERCOPY_KUNIT_TEST
> > +	tristate "KUnit Test for user/kernel boundary protections"
> > +	depends on KUNIT
> > +	default KUNIT_ALL_TESTS
> > +	help
> > +	  This builds the "usercopy_kunit" module that runs sanity checks
> > +	  on the copy_to/from_user infrastructure, making sure basic
> > +	  user/kernel boundary testing is working.
> > +
> 
> Please carry the following line forward as well to be complete assuming
> it is relevant.
> 
> If unsure, say N.

I've explicitly removed that because it would be repetitive if it were
included for all KUnit tests.

-- 
Kees Cook