125 lines
2.9 KiB
C
125 lines
2.9 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2017 Google
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*
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* Authors:
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* Thiebaud Weksteen <tweek@google.com>
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*/
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#include <linux/efi.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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/* read binary bios log from EFI configuration table */
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int tpm_read_log_efi(struct tpm_chip *chip)
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{
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struct efi_tcg2_final_events_table *final_tbl = NULL;
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int final_events_log_size = efi_tpm_final_log_size;
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struct linux_efi_tpm_eventlog *log_tbl;
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struct tpm_bios_log *log;
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u32 log_size;
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u8 tpm_log_version;
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void *tmp;
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int ret;
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if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
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return -ENODEV;
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if (efi.tpm_log == EFI_INVALID_TABLE_ADDR)
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return -ENODEV;
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log = &chip->log;
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log_tbl = memremap(efi.tpm_log, sizeof(*log_tbl), MEMREMAP_WB);
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if (!log_tbl) {
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pr_err("Could not map UEFI TPM log table !\n");
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return -ENOMEM;
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}
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log_size = log_tbl->size;
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memunmap(log_tbl);
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if (!log_size) {
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pr_warn("UEFI TPM log area empty\n");
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return -EIO;
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}
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log_tbl = memremap(efi.tpm_log, sizeof(*log_tbl) + log_size,
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MEMREMAP_WB);
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if (!log_tbl) {
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pr_err("Could not map UEFI TPM log table payload!\n");
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return -ENOMEM;
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}
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/* malloc EventLog space */
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log->bios_event_log = kmemdup(log_tbl->log, log_size, GFP_KERNEL);
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if (!log->bios_event_log) {
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ret = -ENOMEM;
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goto out;
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}
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log->bios_event_log_end = log->bios_event_log + log_size;
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tpm_log_version = log_tbl->version;
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ret = tpm_log_version;
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if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR ||
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final_events_log_size == 0 ||
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tpm_log_version != EFI_TCG2_EVENT_LOG_FORMAT_TCG_2)
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goto out;
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final_tbl = memremap(efi.tpm_final_log,
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sizeof(*final_tbl) + final_events_log_size,
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MEMREMAP_WB);
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if (!final_tbl) {
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pr_err("Could not map UEFI TPM final log\n");
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kfree(log->bios_event_log);
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ret = -ENOMEM;
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goto out;
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}
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/*
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* The 'final events log' size excludes the 'final events preboot log'
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* at its beginning.
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*/
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final_events_log_size -= log_tbl->final_events_preboot_size;
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/*
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* Allocate memory for the 'combined log' where we will append the
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* 'final events log' to.
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*/
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tmp = krealloc(log->bios_event_log,
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log_size + final_events_log_size,
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GFP_KERNEL);
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if (!tmp) {
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kfree(log->bios_event_log);
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ret = -ENOMEM;
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goto out;
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}
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log->bios_event_log = tmp;
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/*
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* Append any of the 'final events log' that didn't also end up in the
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* 'main log'. Events can be logged in both if events are generated
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* between GetEventLog() and ExitBootServices().
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*/
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memcpy((void *)log->bios_event_log + log_size,
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final_tbl->events + log_tbl->final_events_preboot_size,
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final_events_log_size);
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/*
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* The size of the 'combined log' is the size of the 'main log' plus
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* the size of the 'final events log'.
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*/
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log->bios_event_log_end = log->bios_event_log +
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log_size + final_events_log_size;
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out:
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memunmap(final_tbl);
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memunmap(log_tbl);
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return ret;
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}
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