log.c

Go to the documentation of this file.

/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <console/console.h>
#include <security/tpm/tspi.h>
#include <region_file.h>
#include <string.h>
#include <symbols.h>
#include <cbmem.h>
#include <bootstate.h>
#include <vb2_sha.h>
 
static struct tcpa_table *tcpa_cbmem_init(void)
{
        static struct tcpa_table *tclt;
        if (tclt)
                return tclt;
 
        if (cbmem_possibly_online()) {
                tclt = cbmem_find(CBMEM_ID_TCPA_LOG);
                if (!tclt) {
                        size_t tcpa_log_len = sizeof(struct tcpa_table) +
                        MAX_TCPA_LOG_ENTRIES * sizeof(struct tcpa_entry);
                        tclt = cbmem_add(CBMEM_ID_TCPA_LOG, tcpa_log_len);
                        if (tclt) {
                                tclt->max_entries = MAX_TCPA_LOG_ENTRIES;
                                tclt->num_entries = 0;
                        }
                }
        }
        return tclt;
}
 
struct tcpa_table *tcpa_log_init(void)
{
        static struct tcpa_table *tclt;
 
        /* We are dealing here with pre CBMEM environment.
         * If cbmem isn't available use CAR or SRAM */
        if (!cbmem_possibly_online() &&
                !CONFIG(VBOOT_RETURN_FROM_VERSTAGE))
                return (struct tcpa_table *)_tpm_tcpa_log;
        else if (ENV_ROMSTAGE &&
                !CONFIG(VBOOT_RETURN_FROM_VERSTAGE)) {
                tclt = tcpa_cbmem_init();
                if (!tclt)
                        return (struct tcpa_table *)_tpm_tcpa_log;
        } else {
                tclt = tcpa_cbmem_init();
        }
 
        return tclt;
}
 
void tcpa_log_dump(void *unused)
{
        int i, j;
        struct tcpa_table *tclt;
 
        tclt = tcpa_log_init();
        if (!tclt)
                return;
 
        printk(BIOS_INFO, "coreboot TCPA measurements:\n\n");
        for (i = 0; i < tclt->num_entries; i++) {
                struct tcpa_entry *tce = &tclt->entries[i];
                if (tce) {
                        printk(BIOS_INFO, " PCR-%u ", tce->pcr);
 
                        for (j = 0; j < tce->digest_length; j++)
                                printk(BIOS_INFO, "%02x", tce->digest[j]);
 
                        printk(BIOS_INFO, " %s [%s]\n",
                                   tce->digest_type, tce->name);
                }
        }
        printk(BIOS_INFO, "\n");
}
 
void tcpa_log_add_table_entry(const char *name, const uint32_t pcr,
                        enum vb2_hash_algorithm digest_algo,
                        const uint8_t *digest,
                        const size_t digest_len)
{
        struct tcpa_table *tclt = tcpa_log_init();
        if (!tclt) {
                printk(BIOS_WARNING, "TCPA: Log non-existent!\n");
                return;
        }
 
        if (tclt->num_entries >= tclt->max_entries) {
                printk(BIOS_WARNING, "TCPA: TCPA log table is full\n");
                return;
        }
 
        if (!name) {
                printk(BIOS_WARNING, "TCPA: TCPA entry name not set\n");
                return;
        }
 
        struct tcpa_entry *tce = &tclt->entries[tclt->num_entries++];
        strncpy(tce->name, name, TCPA_PCR_HASH_NAME - 1);
        tce->pcr = pcr;
 
        if (digest_len > TCPA_DIGEST_MAX_LENGTH) {
                printk(BIOS_WARNING, "TCPA: PCR digest too long for TCPA log entry\n");
                return;
        }
 
        strncpy(tce->digest_type,
                        vb2_get_hash_algorithm_name(digest_algo),
                        TCPA_PCR_HASH_LEN - 1);
        tce->digest_length = digest_len;
        memcpy(tce->digest, digest, tce->digest_length);
}
 
void tcpa_preram_log_clear(void)
{
        printk(BIOS_INFO, "TCPA: Clearing coreboot TCPA log\n");
        struct tcpa_table *tclt = (struct tcpa_table *)_tpm_tcpa_log;
        tclt->max_entries = MAX_TCPA_LOG_ENTRIES;
        tclt->num_entries = 0;
}
 
#if !CONFIG(VBOOT_RETURN_FROM_VERSTAGE)
static void recover_tcpa_log(int is_recovery)
{
        struct tcpa_table *preram_log = (struct tcpa_table *)_tpm_tcpa_log;
        struct tcpa_table *ram_log = NULL;
        int i;
 
        if (preram_log->num_entries > MAX_PRERAM_TCPA_LOG_ENTRIES) {
                printk(BIOS_WARNING, "TCPA: Pre-RAM TCPA log is too full, possible corruption\n");
                return;
        }
 
        ram_log = tcpa_cbmem_init();
        if (!ram_log) {
                printk(BIOS_WARNING, "TCPA: CBMEM not available something went wrong\n");
                return;
        }
 
        for (i = 0; i < preram_log->num_entries; i++) {
                struct tcpa_entry *tce = &ram_log->entries[ram_log->num_entries++];
                strncpy(tce->name, preram_log->entries[i].name, TCPA_PCR_HASH_NAME - 1);
                tce->pcr = preram_log->entries[i].pcr;
 
                if (preram_log->entries[i].digest_length > TCPA_DIGEST_MAX_LENGTH) {
                        printk(BIOS_WARNING, "TCPA: PCR digest too long for TCPA log entry\n");
                        return;
                }
 
                strncpy(tce->digest_type, preram_log->entries[i].digest_type, TCPA_PCR_HASH_LEN - 1);
                tce->digest_length = MIN(preram_log->entries[i].digest_length, TCPA_DIGEST_MAX_LENGTH);
                memcpy(tce->digest, preram_log->entries[i].digest, tce->digest_length);
        }
}
ROMSTAGE_CBMEM_INIT_HOOK(recover_tcpa_log);
#endif
 
BOOT_STATE_INIT_ENTRY(BS_PAYLOAD_BOOT, BS_ON_ENTRY, tcpa_log_dump, NULL);