1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2017 Google 4 * 5 * Authors: 6 * Thiebaud Weksteen <tweek@google.com> 7 */ 8 9 #include <linux/efi.h> 10 #include <linux/tpm_eventlog.h> 11 12 #include "../tpm.h" 13 #include "common.h" 14 15 /* read binary bios log from EFI configuration table */ 16 int tpm_read_log_efi(struct tpm_chip *chip) 17 { 18 19 struct efi_tcg2_final_events_table *final_tbl = NULL; 20 struct linux_efi_tpm_eventlog *log_tbl; 21 struct tpm_bios_log *log; 22 u32 log_size; 23 u8 tpm_log_version; 24 void *tmp; 25 int ret; 26 27 if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) 28 return -ENODEV; 29 30 if (efi.tpm_log == EFI_INVALID_TABLE_ADDR) 31 return -ENODEV; 32 33 log = &chip->log; 34 35 log_tbl = memremap(efi.tpm_log, sizeof(*log_tbl), MEMREMAP_WB); 36 if (!log_tbl) { 37 pr_err("Could not map UEFI TPM log table !\n"); 38 return -ENOMEM; 39 } 40 41 log_size = log_tbl->size; 42 memunmap(log_tbl); 43 44 log_tbl = memremap(efi.tpm_log, sizeof(*log_tbl) + log_size, 45 MEMREMAP_WB); 46 if (!log_tbl) { 47 pr_err("Could not map UEFI TPM log table payload!\n"); 48 return -ENOMEM; 49 } 50 51 /* malloc EventLog space */ 52 log->bios_event_log = kmemdup(log_tbl->log, log_size, GFP_KERNEL); 53 if (!log->bios_event_log) { 54 ret = -ENOMEM; 55 goto out; 56 } 57 58 log->bios_event_log_end = log->bios_event_log + log_size; 59 tpm_log_version = log_tbl->version; 60 61 ret = tpm_log_version; 62 63 if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR || 64 efi_tpm_final_log_size == 0 || 65 tpm_log_version != EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) 66 goto out; 67 68 final_tbl = memremap(efi.tpm_final_log, 69 sizeof(*final_tbl) + efi_tpm_final_log_size, 70 MEMREMAP_WB); 71 if (!final_tbl) { 72 pr_err("Could not map UEFI TPM final log\n"); 73 kfree(log->bios_event_log); 74 ret = -ENOMEM; 75 goto out; 76 } 77 78 efi_tpm_final_log_size -= log_tbl->final_events_preboot_size; 79 80 tmp = krealloc(log->bios_event_log, 81 log_size + efi_tpm_final_log_size, 82 GFP_KERNEL); 83 if (!tmp) { 84 kfree(log->bios_event_log); 85 ret = -ENOMEM; 86 goto out; 87 } 88 89 log->bios_event_log = tmp; 90 91 /* 92 * Copy any of the final events log that didn't also end up in the 93 * main log. Events can be logged in both if events are generated 94 * between GetEventLog() and ExitBootServices(). 95 */ 96 memcpy((void *)log->bios_event_log + log_size, 97 final_tbl->events + log_tbl->final_events_preboot_size, 98 efi_tpm_final_log_size); 99 log->bios_event_log_end = log->bios_event_log + 100 log_size + efi_tpm_final_log_size; 101 102 out: 103 memunmap(final_tbl); 104 memunmap(log_tbl); 105 return ret; 106 } 107