Messages in this thread | | | Date | Tue, 22 Aug 2023 17:56:03 +0300 | Subject | Re: [PATCH v2] tpm: Don't make vendor check required for probe | From | "Jarkko Sakkinen" <> |
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On Tue Aug 22, 2023 at 5:05 PM EEST, Mario Limonciello wrote: > On 8/22/2023 08:22, Jarkko Sakkinen wrote: > > On Mon Aug 21, 2023 at 5:02 PM EEST, Mario Limonciello wrote: > >> The vendor check introduced by commit 554b841d4703 ("tpm: Disable RNG for > >> all AMD fTPMs") doesn't work properly on a number of Intel fTPMs. On the > >> reported systems the TPM doesn't reply at bootup and returns back the > >> command code. This makes the TPM fail probe. > >> > >> As this isn't crucial for anything but AMD fTPM and AMD fTPM works, check > >> the chip vendor and if it's not AMD don't run the checks. > >> > >> Cc: stable@vger.kernel.org > >> Fixes: 554b841d4703 ("tpm: Disable RNG for all AMD fTPMs") > >> Reported-by: Todd Brandt <todd.e.brandt@intel.com> > >> Reported-by: Patrick Steinhardt <ps@pks.im> > >> Reported-by: Ronan Pigott <ronan@rjp.ie> > >> Reported-by: Raymond Jay Golo <rjgolo@gmail.com> > >> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217804 > >> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> > >> --- > >> v1->v2: > >> * Check x86 vendor for AMD > >> --- > >> drivers/char/tpm/tpm_crb.c | 7 ++++++- > >> 1 file changed, 6 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c > >> index 9eb1a18590123..7faf670201ccc 100644 > >> --- a/drivers/char/tpm/tpm_crb.c > >> +++ b/drivers/char/tpm/tpm_crb.c > >> @@ -465,8 +465,12 @@ static bool crb_req_canceled(struct tpm_chip *chip, u8 status) > >> > >> static int crb_check_flags(struct tpm_chip *chip) > >> { > >> + int ret = 0; > >> +#ifdef CONFIG_X86 > >> u32 val; > >> - int ret; > >> + > >> + if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) > >> + return ret; > >> > >> ret = crb_request_locality(chip, 0); > >> if (ret) > >> @@ -481,6 +485,7 @@ static int crb_check_flags(struct tpm_chip *chip) > >> > >> release: > >> crb_relinquish_locality(chip, 0); > >> +#endif > > > > Looks much better but the main question here is that is this combination > > possible: > > > > 1. AMD CPU > > 2. Non-AMD fTPM (i.e. manufacturer property differs) > > > > BR, Jarkko > > Yes that combination is possible. > > Pluton TPM uses the tpm_crb driver.
Then I guess we'll go with this for now. Thanks for the effort.
Tested-by: Jarkko Sakkinen <jarkko@kernel.org> # QEMU + swtpm Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
I'm planning to send a pull request right after this with the fix so it will land to v6.6-rc1 or v6.6-rc2: https://lore.kernel.org/linux-integrity/20230817201935.31399-1-jarkko@kernel.org/
BR, Jarkko
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