linux/drivers/firmware/efi/tpm.c

106 lines
2.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2017 Google, Inc.
* Thiebaud Weksteen <tweek@google.com>
*/
#define TPM_MEMREMAP(start, size) early_memremap(start, size)
#define TPM_MEMUNMAP(start, size) early_memunmap(start, size)
#include <asm/early_ioremap.h>
#include <linux/efi.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/tpm_eventlog.h>
int efi_tpm_final_log_size;
EXPORT_SYMBOL(efi_tpm_final_log_size);
static int tpm2_calc_event_log_size(void *data, int count, void *size_info)
{
struct tcg_pcr_event2_head *header;
int event_size, size = 0;
while (count > 0) {
header = data + size;
event_size = __calc_tpm2_event_size(header, size_info, true);
if (event_size == 0)
return -1;
size += event_size;
count--;
}
return size;
}
/*
* Reserve the memory associated with the TPM Event Log configuration table.
*/
int __init efi_tpm_eventlog_init(void)
{
struct linux_efi_tpm_eventlog *log_tbl;
struct efi_tcg2_final_events_table *final_tbl;
int tbl_size;
int ret = 0;
if (efi.tpm_log == EFI_INVALID_TABLE_ADDR) {
/*
* We can't calculate the size of the final events without the
* first entry in the TPM log, so bail here.
*/
return 0;
}
log_tbl = early_memremap(efi.tpm_log, sizeof(*log_tbl));
if (!log_tbl) {
pr_err("Failed to map TPM Event Log table @ 0x%lx\n",
efi.tpm_log);
efi.tpm_log = EFI_INVALID_TABLE_ADDR;
return -ENOMEM;
}
tbl_size = sizeof(*log_tbl) + log_tbl->size;
memblock_reserve(efi.tpm_log, tbl_size);
if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR)
goto out;
final_tbl = early_memremap(efi.tpm_final_log, sizeof(*final_tbl));
if (!final_tbl) {
pr_err("Failed to map TPM Final Event Log table @ 0x%lx\n",
efi.tpm_final_log);
efi.tpm_final_log = EFI_INVALID_TABLE_ADDR;
ret = -ENOMEM;
goto out;
}
tbl_size = 0;
if (final_tbl->nr_events != 0) {
void *events = (void *)efi.tpm_final_log
+ sizeof(final_tbl->version)
+ sizeof(final_tbl->nr_events);
tbl_size = tpm2_calc_event_log_size(events,
final_tbl->nr_events,
log_tbl->log);
}
if (tbl_size < 0) {
pr_err(FW_BUG "Failed to parse event in TPM Final Events Log\n");
ret = -EINVAL;
goto out_calc;
}
memblock_reserve((unsigned long)final_tbl,
tbl_size + sizeof(*final_tbl));
efi_tpm_final_log_size = tbl_size;
out_calc:
early_memunmap(final_tbl, sizeof(*final_tbl));
out:
early_memunmap(log_tbl, sizeof(*log_tbl));
return ret;
}