2020-03-30 15:16:19

by Stefan Berger

Subject: [PATCH v2 3/3] tpm: Add support for ACPI logs from TPM2 ACPI table

From: Stefan Berger <[email protected]>

In case of a TPM2 search for a TPM2 ACPI table and if found use it to
find start and length of the log area.

Signed-off-by: Stefan Berger <[email protected]>
---
drivers/char/tpm/eventlog/acpi.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/char/tpm/eventlog/acpi.c b/drivers/char/tpm/eventlog/acpi.c
index 1ef2267c9378..2447f21e4a23 100644
--- a/drivers/char/tpm/eventlog/acpi.c
+++ b/drivers/char/tpm/eventlog/acpi.c
@@ -49,6 +49,8 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
void __iomem *virt;
u64 len, start;
struct tpm_bios_log *log;
+ struct acpi_table_tpm2 *tbl;
+ int format;

log = &chip->log;

@@ -59,7 +61,15 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
return -ENODEV;

if (chip->flags & TPM_CHIP_FLAG_TPM2) {
- return -ENODEV;
+ status = acpi_get_table("TPM2", 1,
+ (struct acpi_table_header **)&tbl);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+ if (tbl->header.length < sizeof(*tbl))
+ return -ENODEV;
+ len = tbl->log_area_minimum_length;
+ start = tbl->log_area_start_address;
+ format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
} else {
/* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
status = acpi_get_table(ACPI_SIG_TCPA, 1,
@@ -79,6 +89,7 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
start = buff->client.log_start_addr;
break;
}
+ format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
}
if (!len) {
dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__);
@@ -99,7 +110,7 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
memcpy_fromio(log->bios_event_log, virt, len);

acpi_os_unmap_iomem(virt, len);
- return EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
+ return format;

err:
kfree(log->bios_event_log);
--
2.14.5

2020-03-30 19:55:39

by Jarkko Sakkinen

Subject: Re: [PATCH v2 3/3] tpm: Add support for ACPI logs from TPM2 ACPI table

On Mon, Mar 30, 2020 at 11:15:36AM -0400, Stefan Berger wrote:
> From: Stefan Berger <[email protected]>
>
> In case of a TPM2 search for a TPM2 ACPI table and if found use it to
> find start and length of the log area.
>
> Signed-off-by: Stefan Berger <[email protected]>

Please use "tpm/eventlog".

There's a typo in the short summary: I guess you meant event log when
you speak of "ACPI log".

Also, I'm not getting the long description e.g. "TPM2 search" is an
alien term.

> ---
> drivers/char/tpm/eventlog/acpi.c | 15 +++++++++++++--
> 1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/char/tpm/eventlog/acpi.c b/drivers/char/tpm/eventlog/acpi.c
> index 1ef2267c9378..2447f21e4a23 100644
> --- a/drivers/char/tpm/eventlog/acpi.c
> +++ b/drivers/char/tpm/eventlog/acpi.c
> @@ -49,6 +49,8 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
> void __iomem *virt;
> u64 len, start;
> struct tpm_bios_log *log;
> + struct acpi_table_tpm2 *tbl;
> + int format;
>
> log = &chip->log;
>
> @@ -59,7 +61,15 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
> return -ENODEV;
>
> if (chip->flags & TPM_CHIP_FLAG_TPM2) {
> - return -ENODEV;
> + status = acpi_get_table("TPM2", 1,
> + (struct acpi_table_header **)&tbl);
> + if (ACPI_FAILURE(status))
> + return -ENODEV;
> + if (tbl->header.length < sizeof(*tbl))
> + return -ENODEV;
> + len = tbl->log_area_minimum_length;
> + start = tbl->log_area_start_address;
> + format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
> } else {
> /* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
> status = acpi_get_table(ACPI_SIG_TCPA, 1,
> @@ -79,6 +89,7 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
> start = buff->client.log_start_addr;
> break;
> }
> + format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
> }
> if (!len) {
> dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__);
> @@ -99,7 +110,7 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
> memcpy_fromio(log->bios_event_log, virt, len);
>
> acpi_os_unmap_iomem(virt, len);
> - return EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
> + return format;
>
> err:
> kfree(log->bios_event_log);
> --
> 2.14.5
>

The code change looks fine but need a review after squashed with 2/3.

/Jarkko