161 lines
3.5 KiB
C
161 lines
3.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2005 IBM Corporation
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*
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* Authors:
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* Seiji Munetoh <munetoh@jp.ibm.com>
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* Stefan Berger <stefanb@us.ibm.com>
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* Reiner Sailer <sailer@watson.ibm.com>
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* Kylene Hall <kjhall@us.ibm.com>
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* Nayna Jain <nayna@linux.vnet.ibm.com>
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*
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* Maintained by: <tpmdd-devel@lists.sourceforge.net>
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*
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* Access to the event log extended by the TCG BIOS of PC platform
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*/
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#include <linux/seq_file.h>
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#include <linux/fs.h>
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#include <linux/security.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/acpi.h>
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#include <linux/tpm_eventlog.h>
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#include "../tpm.h"
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#include "common.h"
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struct acpi_tcpa {
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struct acpi_table_header hdr;
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u16 platform_class;
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union {
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struct client_hdr {
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u32 log_max_len __packed;
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u64 log_start_addr __packed;
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} client;
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struct server_hdr {
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u16 reserved;
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u64 log_max_len __packed;
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u64 log_start_addr __packed;
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} server;
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};
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};
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/* Check that the given log is indeed a TPM2 log. */
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static bool tpm_is_tpm2_log(void *bios_event_log, u64 len)
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{
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struct tcg_efi_specid_event_head *efispecid;
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struct tcg_pcr_event *event_header;
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int n;
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if (len < sizeof(*event_header))
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return false;
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len -= sizeof(*event_header);
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event_header = bios_event_log;
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if (len < sizeof(*efispecid))
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return false;
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efispecid = (struct tcg_efi_specid_event_head *)event_header->event;
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n = memcmp(efispecid->signature, TCG_SPECID_SIG,
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sizeof(TCG_SPECID_SIG));
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return n == 0;
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}
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/* read binary bios log */
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int tpm_read_log_acpi(struct tpm_chip *chip)
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{
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struct acpi_tcpa *buff;
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acpi_status status;
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void __iomem *virt;
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u64 len, start;
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struct tpm_bios_log *log;
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struct acpi_table_tpm2 *tbl;
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struct acpi_tpm2_phy *tpm2_phy;
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int format;
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int ret;
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log = &chip->log;
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/* Unfortuntely ACPI does not associate the event log with a specific
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* TPM, like PPI. Thus all ACPI TPMs will read the same log.
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*/
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if (!chip->acpi_dev_handle)
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return -ENODEV;
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if (chip->flags & TPM_CHIP_FLAG_TPM2) {
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status = acpi_get_table("TPM2", 1,
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(struct acpi_table_header **)&tbl);
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if (ACPI_FAILURE(status))
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return -ENODEV;
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if (tbl->header.length <
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sizeof(*tbl) + sizeof(struct acpi_tpm2_phy))
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return -ENODEV;
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tpm2_phy = (void *)tbl + sizeof(*tbl);
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len = tpm2_phy->log_area_minimum_length;
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start = tpm2_phy->log_area_start_address;
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if (!start || !len)
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return -ENODEV;
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format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
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} else {
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/* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
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status = acpi_get_table(ACPI_SIG_TCPA, 1,
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(struct acpi_table_header **)&buff);
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if (ACPI_FAILURE(status))
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return -ENODEV;
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switch (buff->platform_class) {
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case BIOS_SERVER:
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len = buff->server.log_max_len;
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start = buff->server.log_start_addr;
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break;
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case BIOS_CLIENT:
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default:
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len = buff->client.log_max_len;
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start = buff->client.log_start_addr;
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break;
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}
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format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
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}
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if (!len) {
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dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__);
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return -EIO;
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}
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/* malloc EventLog space */
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log->bios_event_log = kmalloc(len, GFP_KERNEL);
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if (!log->bios_event_log)
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return -ENOMEM;
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log->bios_event_log_end = log->bios_event_log + len;
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ret = -EIO;
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virt = acpi_os_map_iomem(start, len);
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if (!virt)
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goto err;
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memcpy_fromio(log->bios_event_log, virt, len);
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acpi_os_unmap_iomem(virt, len);
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if (chip->flags & TPM_CHIP_FLAG_TPM2 &&
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!tpm_is_tpm2_log(log->bios_event_log, len)) {
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/* try EFI log next */
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ret = -ENODEV;
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goto err;
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}
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return format;
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err:
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kfree(log->bios_event_log);
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log->bios_event_log = NULL;
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return ret;
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}
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