Re: [PATCH v2 06/11] tpm: Add full HMAC and encrypt/decrypt session handling code

[Yujie Liu <yujie.liu@intel.com>]

Hi James,

On Wed, Jan 25, 2023 at 07:59:09AM -0500, James Bottomley wrote:
> On Wed, 2023-01-25 at 07:11 +0800, kernel test robot wrote:
> > Hi James,
> > 
> > I love your patch! Perhaps something to improve:
> > 
> > [auto build test WARNING on char-misc/char-misc-testing]
> > [also build test WARNING on char-misc/char-misc-next char-misc/char-
> > misc-linus zohar-integrity/next-integrity linus/master v6.2-rc5 next-
> > 20230124]
> > [If your patch is applied to the wrong git tree, kindly drop us a
> > note.
> > And when submitting patch, we suggest to use '--base' as documented
> > in
> > https://git-scm.com/docs/git-format-patch#_base_tree_information]
> > 
> > url:   
> > https://github.com/intel-lab-lkp/linux/commits/James-Bottomley/tpm-move-buffer-handling-from-static-inlines-to-real-functions/20230125-020146
> > patch link:   
> > https://lore.kernel.org/r/20230124175516.5984-7-James.Bottomley%40HansenPartnership.com
> > patch subject: [PATCH v2 06/11] tpm: Add full HMAC and
> > encrypt/decrypt session handling code
> > config: arc-allyesconfig
> > (https://download.01.org/0day-ci/archive/20230125/202301250706.deGvd0
> > yq-lkp@intel.com/config)
> > compiler: arceb-elf-gcc (GCC) 12.1.0
> > reproduce (this is a W=1 build):
> >         wget
> > https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross
> >  -O ~/bin/make.cross
> >         chmod +x ~/bin/make.cross
> >         #
> > https://github.com/intel-lab-lkp/linux/commit/dc0fc74718b4a786aba4a954233e8ab3afdcc03c
> >         git remote add linux-review
> > https://github.com/intel-lab-lkp/linux
> >         git fetch --no-tags linux-review James-Bottomley/tpm-move-
> > buffer-handling-from-static-inlines-to-real-functions/20230125-020146
> >         git checkout dc0fc74718b4a786aba4a954233e8ab3afdcc03c
> >         # save the config file
> >         mkdir build_dir && cp config build_dir/.config
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0
> > make.cross W=1 O=build_dir ARCH=arc olddefconfig
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0
> > make.cross W=1 O=build_dir ARCH=arc SHELL=/bin/bash drivers/char/tpm/
> > 
> > If you fix the issue, kindly add following tag where applicable
> > > Reported-by: kernel test robot <lkp@intel.com>
> > 
> > All warnings (new ones prefixed by >>):
> > 
> >    drivers/char/tpm/tpm2-sessions.c:1184:5: warning: no previous
> > prototype for 'tpm2_create_null_primary' [-Wmissing-prototypes]
> >     1184 | int tpm2_create_null_primary(struct tpm_chip *chip) {
> >          |     ^~~~~~~~~~~~~~~~~~~~~~~~
> >    drivers/char/tpm/tpm2-sessions.c: In function
> > 'tpm_buf_check_hmac_response':
> > > > drivers/char/tpm/tpm2-sessions.c:831:1: warning: the frame size
> > > > of 1132 bytes is larger than 1024 bytes [-Wframe-larger-than=]
> >      831 | }
> >          | ^
> >    drivers/char/tpm/tpm2-sessions.c: In function
> > 'tpm_buf_fill_hmac_session':
> >    drivers/char/tpm/tpm2-sessions.c:579:1: warning: the frame size of
> > 1132 bytes is larger than 1024 bytes [-Wframe-larger-than=]
> >      579 | }
> >          | ^
> 
> Is this a test problem?  I can't see why the code would only blow the
> stack on the arc architecture and not on any other ... does it have
> something funny with on stack crypto structures?

This warning is controlled by the value of CONFIG_FRAME_WARN.

For "make ARCH=arc allyesconfig", the default value is 1024, so this
frame warning shows up during the build.

For other arch such as "make ARCH=x86_64 allyesconfig", the default
value would be 2048 and won't have this warning.

Not sure if this is a real problem that need to be fixed, here just
providing above information for your reference.

--
Best Regards,
Yujie