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