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

[James Bottomley <James.Bottomley@HansenPartnership.com>]

On Fri, 2023-02-03 at 14:06 +0800, Yujie Liu wrote:
> 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.deGv
> > > d0
> > > 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.

Is there something weird about arc, though, since a quick trawl through
defconfigs shows quite a few systems (including i386) have it set to
1024:

mips/configs/lemote2f_defconfig:CONFIG_FRAME_WARN=1024
mips/configs/loongson2k_defconfig:CONFIG_FRAME_WARN=1024
powerpc/configs/fsl-emb-nonhw.config:CONFIG_FRAME_WARN=1024
um/configs/x86_64_defconfig:CONFIG_FRAME_WARN=1024
x86/configs/i386_defconfig:CONFIG_FRAME_WARN=1024

That also seems to show, by the way, that the default on arc should be
the standard 2048.

James