| Message ID | 20230822203912.2256229-1-jarkko@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] tpm: Enable hwrng only for Pluton on AMD CPUs | expand |
On Tue, Aug 22, 2023 at 11:39:12PM +0300, Jarkko Sakkinen 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. > > Since only Microsoft Pluton is the only known combination of AMD CPU and > fTPM from other vendor, disable hwrng otherwise. In order to make sysadmin > aware of this, print also info message to the klog. > > Cc: stable@vger.kernel.org > Fixes: 554b841d4703 ("tpm: Disable RNG for all AMD fTPMs") > Reported-by: Todd Brandt <todd.e.brandt@intel.com> > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217804 > Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> > --- > v2: > * CONFIG_X86 Did you mean to wrap the crb_acpi_add chunk with CONFIG_X86? > * Removed "Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>" > * Removed "Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>" > --- > drivers/char/tpm/tpm_crb.c | 31 ++++++------------------------- > 1 file changed, 6 insertions(+), 25 deletions(-) > > diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c > index 65ff4d2fbe8d..28448bfd4062 100644 > --- a/drivers/char/tpm/tpm_crb.c > +++ b/drivers/char/tpm/tpm_crb.c > @@ -463,28 +463,6 @@ static bool crb_req_canceled(struct tpm_chip *chip, u8 status) > return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE; > } > > -static int crb_check_flags(struct tpm_chip *chip) > -{ > - u32 val; > - int ret; > - > - ret = crb_request_locality(chip, 0); > - if (ret) > - return ret; > - > - ret = tpm2_get_tpm_pt(chip, TPM2_PT_MANUFACTURER, &val, NULL); > - if (ret) > - goto release; > - > - if (val == 0x414D4400U /* AMD */) > - chip->flags |= TPM_CHIP_FLAG_HWRNG_DISABLED; > - > -release: > - crb_relinquish_locality(chip, 0); > - > - return ret; > -} > - > static const struct tpm_class_ops tpm_crb = { > .flags = TPM_OPS_AUTO_STARTUP, > .status = crb_status, > @@ -827,9 +805,12 @@ static int crb_acpi_add(struct acpi_device *device) > if (rc) > goto out; > > - rc = crb_check_flags(chip); > - if (rc) > - goto out; > + /* A quirk for https://www.amd.com/en/support/kb/faq/pa-410 */ > + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD && > + priv->sm != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) { > + dev_info(dev, "Disabling hwrng\n"); > + chip->flags |= TPM_CHIP_FLAG_HWRNG_DISABLED; > + } > > rc = tpm_chip_register(chip); > > -- > 2.39.2 >
On Wed Aug 23, 2023 at 12:28 AM EEST, Jerry Snitselaar wrote: > On Tue, Aug 22, 2023 at 11:39:12PM +0300, Jarkko Sakkinen 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. > > > > Since only Microsoft Pluton is the only known combination of AMD CPU and > > fTPM from other vendor, disable hwrng otherwise. In order to make sysadmin > > aware of this, print also info message to the klog. > > > > Cc: stable@vger.kernel.org > > Fixes: 554b841d4703 ("tpm: Disable RNG for all AMD fTPMs") > > Reported-by: Todd Brandt <todd.e.brandt@intel.com> > > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217804 > > Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> > > --- > > v2: > > * CONFIG_X86 > > Did you mean to wrap the crb_acpi_add chunk with CONFIG_X86? Yup :-/ $ git diff diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c index 28448bfd4062..ea085b14ab7c 100644 --- a/drivers/char/tpm/tpm_crb.c +++ b/drivers/char/tpm/tpm_crb.c @@ -805,12 +805,14 @@ static int crb_acpi_add(struct acpi_device *device) if (rc) goto out; +#ifdef CONFIG_X86 /* A quirk for https://www.amd.com/en/support/kb/faq/pa-410 */ if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD && priv->sm != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) { dev_info(dev, "Disabling hwrng\n"); chip->flags |= TPM_CHIP_FLAG_HWRNG_DISABLED; } +#endif /* CONFIG_X86 */ rc = tpm_chip_register(chip); [also linux-sgx leaked by mistake to my git-send-email command line] I sent a new one: https://lkml.org/lkml/2023/8/22/1288 BR, Jarkko
diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c index 65ff4d2fbe8d..28448bfd4062 100644 --- a/drivers/char/tpm/tpm_crb.c +++ b/drivers/char/tpm/tpm_crb.c @@ -463,28 +463,6 @@ static bool crb_req_canceled(struct tpm_chip *chip, u8 status) return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE; } -static int crb_check_flags(struct tpm_chip *chip) -{ - u32 val; - int ret; - - ret = crb_request_locality(chip, 0); - if (ret) - return ret; - - ret = tpm2_get_tpm_pt(chip, TPM2_PT_MANUFACTURER, &val, NULL); - if (ret) - goto release; - - if (val == 0x414D4400U /* AMD */) - chip->flags |= TPM_CHIP_FLAG_HWRNG_DISABLED; - -release: - crb_relinquish_locality(chip, 0); - - return ret; -} - static const struct tpm_class_ops tpm_crb = { .flags = TPM_OPS_AUTO_STARTUP, .status = crb_status, @@ -827,9 +805,12 @@ static int crb_acpi_add(struct acpi_device *device) if (rc) goto out; - rc = crb_check_flags(chip); - if (rc) - goto out; + /* A quirk for https://www.amd.com/en/support/kb/faq/pa-410 */ + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD && + priv->sm != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) { + dev_info(dev, "Disabling hwrng\n"); + chip->flags |= TPM_CHIP_FLAG_HWRNG_DISABLED; + } rc = tpm_chip_register(chip);
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. Since only Microsoft Pluton is the only known combination of AMD CPU and fTPM from other vendor, disable hwrng otherwise. In order to make sysadmin aware of this, print also info message to the klog. Cc: stable@vger.kernel.org Fixes: 554b841d4703 ("tpm: Disable RNG for all AMD fTPMs") Reported-by: Todd Brandt <todd.e.brandt@intel.com> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217804 Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> --- v2: * CONFIG_X86 * Removed "Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>" * Removed "Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>" --- drivers/char/tpm/tpm_crb.c | 31 ++++++------------------------- 1 file changed, 6 insertions(+), 25 deletions(-)