On Thu, Jun 25, 2020 at 05:34:38AM +0300, Jarkko Sakkinen wrote:
> On Wed, Jun 24, 2020 at 08:38:25PM -0400, Stefan Berger wrote:
> > On 6/24/20 8:00 PM, Jarkko Sakkinen wrote:
> > > On Tue, Jun 23, 2020 at 08:06:35AM -0400, Stefan Berger wrote:
> > > > From: Stefan Berger <stef...@linux.ibm.com>
> > > >
> > > > Recent extensions of the TPM2 ACPI table added 3 more fields
> > > > including 12 bytes of start method specific parameters and Log Area
> > > > Minimum Length (u32) and Log Area Start Address (u64). So, we extend
> > > > the existing structure with these fields to allow non-UEFI systems
> > > > to access the TPM2's log.
> > > >
> > > > The specification that has the new fields is the following:
> > > > TCG ACPI Specification
> > > > Family "1.2" and "2.0"
> > > > Version 1.2, Revision 8
> > > >
> > > > Adapt all existing table size calculations to use
> > > > offsetof(struct acpi_table_tpm2, start_method_specific)
> > > > [where start_method_specific is a newly added field]
> > > > rather than sizeof(struct acpi_table_tpm2) so that the addition
> > > > of the new fields does not affect current systems that may not
> > > > have them.
> > > >
> > > I found at least one regression from this patch. Please remove my
> > > reviewed-by comment form the next version.
> > >
> > > Should have:
> > >
> > > Link:
> > > https://trustedcomputinggroup.org/wp-content/uploads/TCG_ACPIGeneralSpecification_v1.20_r8.pdf
> > >
> > > Please, add this.
> > >
> > > > Signed-off-by: Stefan Berger <stef...@linux.ibm.com>
> > > > Cc: linux-a...@vger.kernel.org
> > > > Acked-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
> > > > Reviewed-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
> > > > ---
> > > > drivers/char/tpm/tpm_crb.c | 13 ++++++++++---
> > > > drivers/char/tpm/tpm_tis.c | 4 +++-
> > > > include/acpi/actbl3.h | 5 +++--
> > > > 3 files changed, 16 insertions(+), 6 deletions(-)
> > > >
> > > > diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> > > > index a9dcf31eadd2..0565aa5482f9 100644
> > > > --- a/drivers/char/tpm/tpm_crb.c
> > > > +++ b/drivers/char/tpm/tpm_crb.c
> > > > @@ -669,7 +669,9 @@ static int crb_acpi_add(struct acpi_device *device)
> > > > status = acpi_get_table(ACPI_SIG_TPM2, 1,
> > > > (struct acpi_table_header **) &buf);
> > > > - if (ACPI_FAILURE(status) || buf->header.length < sizeof(*buf)) {
> > > > + if (ACPI_FAILURE(status) || buf->header.length <
> > > > + offsetof(struct acpi_table_tpm2,
> > > > + start_method_specific)) {
> > > > dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
> > > > return -EINVAL;
> > > > }
> > > > @@ -684,14 +686,19 @@ static int crb_acpi_add(struct acpi_device
> > > > *device)
> > > > return -ENOMEM;
> > > > if (sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
> > > > - if (buf->header.length < (sizeof(*buf) +
> > > > sizeof(*crb_smc))) {
> > > > + if (buf->header.length <
> > > > + (offsetof(struct acpi_table_tpm2,
> > > > + start_method_specific) +
> > > Should be
> > >
> > > offsetof(struct acpti_table_tpm2, log_area_minimum_length)
> >
> >
> > The old code had sizeof(*buf) with buf being 'struct acpi_table_tpm2' and
> > that was equivalent to offsetof(struct acpi_table_tpm2,
> > start_method_specific) since 'start_method_specific' is the first new field
> > that we are adding right here. Also see 3rd paragraph in the patch
> > description. The replacement rule described there should apply to all
> > sizeof() calculations on 'struct acpi_table_tpm2.'
>
> Aren't you ignoring sizeof(*crb_smc) then?
Duh, it's there I see. Sorry, my mistake.
Please put the new fields in a separate struct:
struct acpi_tpm2_phy {
u8 start_method_specific[12];
u32 log_area_minimum_length;
u64 log_area_start_address;
};
This way we don't have to obfuscate all the calculations and zero out
the need for 1/2 in this patch set.
/Jarkko
