linux/drivers/char/tpm/tpm_eventlog_efi.c

67 lines
1.5 KiB
C

/*
* Copyright (C) 2017 Google
*
* Authors:
* Thiebaud Weksteen <tweek@google.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <linux/efi.h>
#include <linux/tpm_eventlog.h>
#include "tpm.h"
/* read binary bios log from EFI configuration table */
int tpm_read_log_efi(struct tpm_chip *chip)
{
struct linux_efi_tpm_eventlog *log_tbl;
struct tpm_bios_log *log;
u32 log_size;
u8 tpm_log_version;
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);
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 = kmalloc(log_size, GFP_KERNEL);
if (!log->bios_event_log)
goto err_memunmap;
memcpy(log->bios_event_log, log_tbl->log, log_size);
log->bios_event_log_end = log->bios_event_log + log_size;
tpm_log_version = log_tbl->version;
memunmap(log_tbl);
return tpm_log_version;
err_memunmap:
memunmap(log_tbl);
return -ENOMEM;
}