1 /* 2 * Copyright (C) 2017 Google 3 * 4 * Authors: 5 * Thiebaud Weksteen <tweek@google.com> 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 * 12 */ 13 14 #include <linux/efi.h> 15 #include <linux/tpm_eventlog.h> 16 17 #include "../tpm.h" 18 #include "common.h" 19 20 /* read binary bios log from EFI configuration table */ 21 int tpm_read_log_efi(struct tpm_chip *chip) 22 { 23 24 struct linux_efi_tpm_eventlog *log_tbl; 25 struct tpm_bios_log *log; 26 u32 log_size; 27 u8 tpm_log_version; 28 29 if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) 30 return -ENODEV; 31 32 if (efi.tpm_log == EFI_INVALID_TABLE_ADDR) 33 return -ENODEV; 34 35 log = &chip->log; 36 37 log_tbl = memremap(efi.tpm_log, sizeof(*log_tbl), MEMREMAP_WB); 38 if (!log_tbl) { 39 pr_err("Could not map UEFI TPM log table !\n"); 40 return -ENOMEM; 41 } 42 43 log_size = log_tbl->size; 44 memunmap(log_tbl); 45 46 log_tbl = memremap(efi.tpm_log, sizeof(*log_tbl) + log_size, 47 MEMREMAP_WB); 48 if (!log_tbl) { 49 pr_err("Could not map UEFI TPM log table payload!\n"); 50 return -ENOMEM; 51 } 52 53 /* malloc EventLog space */ 54 log->bios_event_log = kmemdup(log_tbl->log, log_size, GFP_KERNEL); 55 if (!log->bios_event_log) 56 goto err_memunmap; 57 log->bios_event_log_end = log->bios_event_log + log_size; 58 59 tpm_log_version = log_tbl->version; 60 memunmap(log_tbl); 61 return tpm_log_version; 62 63 err_memunmap: 64 memunmap(log_tbl); 65 return -ENOMEM; 66 } 67