Messages in this thread | | | Date | Wed, 10 May 2017 15:34:58 +0300 | From | Jarkko Sakkinen <> | Subject | Re: [PATCH] tpm: fix byte order related arithmetic inconsistency in tpm_getcap() |
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On Tue, May 09, 2017 at 09:13:08AM -0600, Jason Gunthorpe wrote: > On Tue, May 09, 2017 at 05:13:53PM +0300, Jarkko Sakkinen wrote: > > On Sun, May 07, 2017 at 08:50:02PM +0300, Jarkko Sakkinen wrote: > > > You should not do arithmetic with __be32 or __le32 types because > > > sometimes it results incorrect results. Calculations must be done only > > > with integers that are in in the CPU byte order. This commit migrates > > > tpm_getcap() to struct tpm_buf in order to sort out these issues. > > > > > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> > > > Now this should work as Robertos patches move byte order conversion > > > where it should be. Sadly I'm out of reach to my Dell E6400 laptop > > > that I use for TPM 1.2 testing. > > > drivers/char/tpm/tpm-interface.c | 30 ++++++++++++++++-------------- > > > drivers/char/tpm/tpm.h | 13 ------------- > > > 2 files changed, 16 insertions(+), 27 deletions(-) > > > > I've now tested this with TPM 1.2. Any complains? > > Seems reasonable, but which linke had the problematic arithmetic? > > Jason
Arithmetic should work but it's not a good practice to do additions, substractions or multiplications in any other byte order than the CPU byte order.
sparse also complains about this.
/Jarkko
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