diff options
Diffstat (limited to 'drivers/char/tpm/eventlog/acpi.c')
| -rw-r--r-- | drivers/char/tpm/eventlog/acpi.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/char/tpm/eventlog/acpi.c b/drivers/char/tpm/eventlog/acpi.c new file mode 100644 index 000000000..cd266021d --- /dev/null +++ b/drivers/char/tpm/eventlog/acpi.c @@ -0,0 +1,170 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2005 IBM Corporation + * + * Authors: + * Seiji Munetoh <munetoh@jp.ibm.com> + * Stefan Berger <stefanb@us.ibm.com> + * Reiner Sailer <sailer@watson.ibm.com> + * Kylene Hall <kjhall@us.ibm.com> + * Nayna Jain <nayna@linux.vnet.ibm.com> + * + * Maintained by: <tpmdd-devel@lists.sourceforge.net> + * + * Access to the event log extended by the TCG BIOS of PC platform + */ + +#include <linux/seq_file.h> +#include <linux/fs.h> +#include <linux/security.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/acpi.h> +#include <linux/tpm_eventlog.h> + +#include "../tpm.h" +#include "common.h" + +struct acpi_tcpa { + struct acpi_table_header hdr; + u16 platform_class; + union { + struct client_hdr { + u32 log_max_len __packed; + u64 log_start_addr __packed; + } client; + struct server_hdr { + u16 reserved; + u64 log_max_len __packed; + u64 log_start_addr __packed; + } server; + }; +}; + +/* Check that the given log is indeed a TPM2 log. */ +static bool tpm_is_tpm2_log(void *bios_event_log, u64 len) +{ + struct tcg_efi_specid_event_head *efispecid; + struct tcg_pcr_event *event_header; + int n; + + if (len < sizeof(*event_header)) + return false; + len -= sizeof(*event_header); + event_header = bios_event_log; + + if (len < sizeof(*efispecid)) + return false; + efispecid = (struct tcg_efi_specid_event_head *)event_header->event; + + n = memcmp(efispecid->signature, TCG_SPECID_SIG, + sizeof(TCG_SPECID_SIG)); + return n == 0; +} + +/* read binary bios log */ +int tpm_read_log_acpi(struct tpm_chip *chip) +{ + struct acpi_tcpa *buff; + acpi_status status; + void __iomem *virt; + u64 len, start; + struct tpm_bios_log *log; + struct acpi_table_tpm2 *tbl; + struct acpi_tpm2_phy *tpm2_phy; + int format; + int ret; + + log = &chip->log; + + /* Unfortuntely ACPI does not associate the event log with a specific + * TPM, like PPI. Thus all ACPI TPMs will read the same log. + */ + if (!chip->acpi_dev_handle) + return -ENODEV; + + if (chip->flags & TPM_CHIP_FLAG_TPM2) { + status = acpi_get_table("TPM2", 1, + (struct acpi_table_header **)&tbl); + if (ACPI_FAILURE(status)) + return -ENODEV; + + if (tbl->header.length < + sizeof(*tbl) + sizeof(struct acpi_tpm2_phy)) { + acpi_put_table((struct acpi_table_header *)tbl); + return -ENODEV; + } + + tpm2_phy = (void *)tbl + sizeof(*tbl); + len = tpm2_phy->log_area_minimum_length; + + start = tpm2_phy->log_area_start_address; + if (!start || !len) { + acpi_put_table((struct acpi_table_header *)tbl); + return -ENODEV; + } + + acpi_put_table((struct acpi_table_header *)tbl); + 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, + (struct acpi_table_header **)&buff); + if (ACPI_FAILURE(status)) + return -ENODEV; + + switch (buff->platform_class) { + case BIOS_SERVER: + len = buff->server.log_max_len; + start = buff->server.log_start_addr; + break; + case BIOS_CLIENT: + default: + len = buff->client.log_max_len; + start = buff->client.log_start_addr; + break; + } + + acpi_put_table((struct acpi_table_header *)buff); + format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2; + } + + if (!len) { + dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__); + return -EIO; + } + + /* malloc EventLog space */ + log->bios_event_log = kmalloc(len, GFP_KERNEL); + if (!log->bios_event_log) + return -ENOMEM; + + log->bios_event_log_end = log->bios_event_log + len; + + ret = -EIO; + virt = acpi_os_map_iomem(start, len); + if (!virt) { + dev_warn(&chip->dev, "%s: Failed to map ACPI memory\n", __func__); + /* try EFI log next */ + ret = -ENODEV; + goto err; + } + + memcpy_fromio(log->bios_event_log, virt, len); + + acpi_os_unmap_iomem(virt, len); + + if (chip->flags & TPM_CHIP_FLAG_TPM2 && + !tpm_is_tpm2_log(log->bios_event_log, len)) { + /* try EFI log next */ + ret = -ENODEV; + goto err; + } + + return format; + +err: + kfree(log->bios_event_log); + log->bios_event_log = NULL; + return ret; +} |