1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2017 Google, Inc. 4 * Thiebaud Weksteen <tweek@google.com> 5 */ 6 7 #define TPM_MEMREMAP(start, size) early_memremap(start, size) 8 #define TPM_MEMUNMAP(start, size) early_memunmap(start, size) 9 10 #include <asm/early_ioremap.h> 11 #include <linux/efi.h> 12 #include <linux/init.h> 13 #include <linux/memblock.h> 14 #include <linux/tpm_eventlog.h> 15 16 int efi_tpm_final_log_size; 17 EXPORT_SYMBOL(efi_tpm_final_log_size); 18 19 static int __init tpm2_calc_event_log_size(void *data, int count, void *size_info) 20 { 21 struct tcg_pcr_event2_head *header; 22 int event_size, size = 0; 23 24 while (count > 0) { 25 header = data + size; 26 event_size = __calc_tpm2_event_size(header, size_info, true); 27 if (event_size == 0) 28 return -1; 29 size += event_size; 30 count--; 31 } 32 33 return size; 34 } 35 36 /* 37 * Reserve the memory associated with the TPM Event Log configuration table. 38 */ 39 int __init efi_tpm_eventlog_init(void) 40 { 41 struct linux_efi_tpm_eventlog *log_tbl; 42 struct efi_tcg2_final_events_table *final_tbl; 43 int tbl_size; 44 int ret = 0; 45 46 if (efi.tpm_log == EFI_INVALID_TABLE_ADDR) { 47 /* 48 * We can't calculate the size of the final events without the 49 * first entry in the TPM log, so bail here. 50 */ 51 return 0; 52 } 53 54 log_tbl = early_memremap(efi.tpm_log, sizeof(*log_tbl)); 55 if (!log_tbl) { 56 pr_err("Failed to map TPM Event Log table @ 0x%lx\n", 57 efi.tpm_log); 58 efi.tpm_log = EFI_INVALID_TABLE_ADDR; 59 return -ENOMEM; 60 } 61 62 tbl_size = sizeof(*log_tbl) + log_tbl->size; 63 memblock_reserve(efi.tpm_log, tbl_size); 64 65 if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR) { 66 pr_info("TPM Final Events table not present\n"); 67 goto out; 68 } else if (log_tbl->version != EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) { 69 pr_warn(FW_BUG "TPM Final Events table invalid\n"); 70 goto out; 71 } 72 73 final_tbl = early_memremap(efi.tpm_final_log, sizeof(*final_tbl)); 74 75 if (!final_tbl) { 76 pr_err("Failed to map TPM Final Event Log table @ 0x%lx\n", 77 efi.tpm_final_log); 78 efi.tpm_final_log = EFI_INVALID_TABLE_ADDR; 79 ret = -ENOMEM; 80 goto out; 81 } 82 83 tbl_size = 0; 84 if (final_tbl->nr_events != 0) { 85 void *events = (void *)efi.tpm_final_log 86 + sizeof(final_tbl->version) 87 + sizeof(final_tbl->nr_events); 88 89 tbl_size = tpm2_calc_event_log_size(events, 90 final_tbl->nr_events, 91 log_tbl->log); 92 } 93 94 if (tbl_size < 0) { 95 pr_err(FW_BUG "Failed to parse event in TPM Final Events Log\n"); 96 ret = -EINVAL; 97 goto out_calc; 98 } 99 100 memblock_reserve(efi.tpm_final_log, 101 tbl_size + sizeof(*final_tbl)); 102 efi_tpm_final_log_size = tbl_size; 103 104 out_calc: 105 early_memunmap(final_tbl, sizeof(*final_tbl)); 106 out: 107 early_memunmap(log_tbl, sizeof(*log_tbl)); 108 return ret; 109 } 110 111