cregit-Linux how code gets into the kernel

Release 4.11 drivers/char/tpm/tpm1_eventlog.c

Directory: drivers/char/tpm
/*
 * Copyright (C) 2005, 2012 IBM Corporation
 *
 * Authors:
 *      Kent Yoder <key@linux.vnet.ibm.com>
 *      Seiji Munetoh <munetoh@jp.ibm.com>
 *      Stefan Berger <stefanb@us.ibm.com>
 *      Reiner Sailer <sailer@watson.ibm.com>
 *      Kylene Hall <kjhall@us.ibm.com>
 *      Nayna Jain <nayna@linux.vnet.ibm.com>
 *
 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
 *
 * Access to the event log created by a system's firmware / BIOS
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 */

#include <linux/seq_file.h>
#include <linux/fs.h>
#include <linux/security.h>
#include <linux/module.h>
#include <linux/slab.h>

#include "tpm.h"
#include "tpm_eventlog.h"



static const char* tcpa_event_type_strings[] = {
	"PREBOOT",
	"POST CODE",
	"",
	"NO ACTION",
	"SEPARATOR",
	"ACTION",
	"EVENT TAG",
	"S-CRTM Contents",
	"S-CRTM Version",
	"CPU Microcode",
	"Platform Config Flags",
	"Table of Devices",
	"Compact Hash",
	"IPL",
	"IPL Partition Data",
	"Non-Host Code",
	"Non-Host Config",
	"Non-Host Info"
};


static const char* tcpa_pc_event_id_strings[] = {
	"",
	"SMBIOS",
	"BIS Certificate",
	"POST BIOS ",
	"ESCD ",
	"CMOS",
	"NVRAM",
	"Option ROM",
	"Option ROM config",
	"",
	"Option ROM microcode ",
	"S-CRTM Version",
	"S-CRTM Contents ",
	"POST Contents ",
	"Table of Devices",
};

/* returns pointer to start of pos. entry of tcg log */

static void *tpm_bios_measurements_start(struct seq_file *m, loff_t *pos) { loff_t i; struct tpm_chip *chip = m->private; struct tpm_bios_log *log = &chip->log; void *addr = log->bios_event_log; void *limit = log->bios_event_log_end; struct tcpa_event *event; u32 converted_event_size; u32 converted_event_type; /* read over *pos measurements */ for (i = 0; i < *pos; i++) { event = addr; converted_event_size = do_endian_conversion(event->event_size); converted_event_type = do_endian_conversion(event->event_type); if ((addr + sizeof(struct tcpa_event)) < limit) { if ((converted_event_type == 0) && (converted_event_size == 0)) return NULL; addr += (sizeof(struct tcpa_event) + converted_event_size); } } /* now check if current entry is valid */ if ((addr + sizeof(struct tcpa_event)) >= limit) return NULL; event = addr; converted_event_size = do_endian_conversion(event->event_size); converted_event_type = do_endian_conversion(event->event_type); if (((converted_event_type == 0) && (converted_event_size == 0)) || ((addr + sizeof(struct tcpa_event) + converted_event_size) >= limit)) return NULL; return addr; }

Contributors

PersonTokensPropCommitsCommitProp
Kylene Jo Hall15769.16%250.00%
Hon Ching (Vicky) Lo5825.55%125.00%
Nayna Jain125.29%125.00%
Total227100.00%4100.00%


static void *tpm_bios_measurements_next(struct seq_file *m, void *v, loff_t *pos) { struct tcpa_event *event = v; struct tpm_chip *chip = m->private; struct tpm_bios_log *log = &chip->log; void *limit = log->bios_event_log_end; u32 converted_event_size; u32 converted_event_type; converted_event_size = do_endian_conversion(event->event_size); v += sizeof(struct tcpa_event) + converted_event_size; /* now check if current entry is valid */ if ((v + sizeof(struct tcpa_event)) >= limit) return NULL; event = v; converted_event_size = do_endian_conversion(event->event_size); converted_event_type = do_endian_conversion(event->event_type); if (((converted_event_type == 0) && (converted_event_size == 0)) || ((v + sizeof(struct tcpa_event) + converted_event_size) >= limit)) return NULL; (*pos)++; return v; }

Contributors

PersonTokensPropCommitsCommitProp
Kylene Jo Hall11469.94%250.00%
Hon Ching (Vicky) Lo3722.70%125.00%
Nayna Jain127.36%125.00%
Total163100.00%4100.00%


static void tpm_bios_measurements_stop(struct seq_file *m, void *v) { }

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Kylene Jo Hall14100.00%1100.00%
Total14100.00%1100.00%


static int get_event_name(char *dest, struct tcpa_event *event, unsigned char * event_entry) { const char *name = ""; /* 41 so there is room for 40 data and 1 nul */ char data[41] = ""; int i, n_len = 0, d_len = 0; struct tcpa_pc_event *pc_event; switch (do_endian_conversion(event->event_type)) { case PREBOOT: case POST_CODE: case UNUSED: case NO_ACTION: case SCRTM_CONTENTS: case SCRTM_VERSION: case CPU_MICROCODE: case PLATFORM_CONFIG_FLAGS: case TABLE_OF_DEVICES: case COMPACT_HASH: case IPL: case IPL_PARTITION_DATA: case NONHOST_CODE: case NONHOST_CONFIG: case NONHOST_INFO: name = tcpa_event_type_strings[do_endian_conversion (event->event_type)]; n_len = strlen(name); break; case SEPARATOR: case ACTION: if (MAX_TEXT_EVENT > do_endian_conversion(event->event_size)) { name = event_entry; n_len = do_endian_conversion(event->event_size); } break; case EVENT_TAG: pc_event = (struct tcpa_pc_event *)event_entry; /* ToDo Row data -> Base64 */ switch (do_endian_conversion(pc_event->event_id)) { case SMBIOS: case BIS_CERT: case CMOS: case NVRAM: case OPTION_ROM_EXEC: case OPTION_ROM_CONFIG: case S_CRTM_VERSION: name = tcpa_pc_event_id_strings[do_endian_conversion (pc_event->event_id)]; n_len = strlen(name); break; /* hash data */ case POST_BIOS_ROM: case ESCD: case OPTION_ROM_MICROCODE: case S_CRTM_CONTENTS: case POST_CONTENTS: name = tcpa_pc_event_id_strings[do_endian_conversion (pc_event->event_id)]; n_len = strlen(name); for (i = 0; i < 20; i++) d_len += sprintf(&data[2*i], "%02x", pc_event->event_data[i]); break; default: break; } default: break; } return snprintf(dest, MAX_TEXT_EVENT, "[%.*s%.*s]", n_len, name, d_len, data); }

Contributors

PersonTokensPropCommitsCommitProp
Kylene Jo Hall26181.82%120.00%
Seiji Munetoh3210.03%120.00%
Hon Ching (Vicky) Lo216.58%120.00%
Andrew Morton30.94%120.00%
Eric Paris20.63%120.00%
Total319100.00%5100.00%


static int tpm_binary_bios_measurements_show(struct seq_file *m, void *v) { struct tcpa_event *event = v; struct tcpa_event temp_event; char *temp_ptr; int i; memcpy(&temp_event, event, sizeof(struct tcpa_event)); /* convert raw integers for endianness */ temp_event.pcr_index = do_endian_conversion(event->pcr_index); temp_event.event_type = do_endian_conversion(event->event_type); temp_event.event_size = do_endian_conversion(event->event_size); temp_ptr = (char *) &temp_event; for (i = 0; i < (sizeof(struct tcpa_event) - 1) ; i++) seq_putc(m, temp_ptr[i]); temp_ptr = (char *) v; for (i = (sizeof(struct tcpa_event) - 1); i < (sizeof(struct tcpa_event) + temp_event.event_size); i++) seq_putc(m, temp_ptr[i]); return 0; }

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PersonTokensPropCommitsCommitProp
Hon Ching (Vicky) Lo6235.84%125.00%
Harald Hoyer5230.06%125.00%
Kylene Jo Hall5230.06%125.00%
Seiji Munetoh74.05%125.00%
Total173100.00%4100.00%


static int tpm_bios_measurements_release(struct inode *inode, struct file *file) { struct seq_file *seq = (struct seq_file *)file->private_data; struct tpm_chip *chip = (struct tpm_chip *)seq->private; put_device(&chip->dev); return seq_release(inode, file); }

Contributors

PersonTokensPropCommitsCommitProp
Kylene Jo Hall4473.33%266.67%
Nayna Jain1626.67%133.33%
Total60100.00%3100.00%


static int tpm_ascii_bios_measurements_show(struct seq_file *m, void *v) { int len = 0; char *eventname; struct tcpa_event *event = v; unsigned char *event_entry = (unsigned char *)(v + sizeof(struct tcpa_event)); eventname = kmalloc(MAX_TEXT_EVENT, GFP_KERNEL); if (!eventname) { printk(KERN_ERR "%s: ERROR - No Memory for event name\n ", __func__); return -EFAULT; } /* 1st: PCR */ seq_printf(m, "%2d ", do_endian_conversion(event->pcr_index)); /* 2nd: SHA1 */ seq_printf(m, "%20phN", event->pcr_value); /* 3rd: event type identifier */ seq_printf(m, " %02x", do_endian_conversion(event->event_type)); len += get_event_name(eventname, event, event_entry); /* 4th: eventname <= max + \'0' delimiter */ seq_printf(m, " %s\n", eventname); kfree(eventname); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Kylene Jo Hall14294.67%250.00%
Hon Ching (Vicky) Lo74.67%125.00%
Andy Shevchenko10.67%125.00%
Total150100.00%4100.00%

static const struct seq_operations tpm_ascii_b_measurements_seqops = { .start = tpm_bios_measurements_start, .next = tpm_bios_measurements_next, .stop = tpm_bios_measurements_stop, .show = tpm_ascii_bios_measurements_show, }; static const struct seq_operations tpm_binary_b_measurements_seqops = { .start = tpm_bios_measurements_start, .next = tpm_bios_measurements_next, .stop = tpm_bios_measurements_stop, .show = tpm_binary_bios_measurements_show, };
static int tpm_bios_measurements_open(struct inode *inode, struct file *file) { int err; struct seq_file *seq; struct tpm_chip_seqops *chip_seqops; const struct seq_operations *seqops; struct tpm_chip *chip; inode_lock(inode); if (!inode->i_private) { inode_unlock(inode); return -ENODEV; } chip_seqops = (struct tpm_chip_seqops *)inode->i_private; seqops = chip_seqops->seqops; chip = chip_seqops->chip; get_device(&chip->dev); inode_unlock(inode); /* now register seq file */ err = seq_open(file, seqops); if (!err) { seq = file->private_data; seq->private = chip; } return err; }

Contributors

PersonTokensPropCommitsCommitProp
Kylene Jo Hall6851.91%233.33%
Nayna Jain5945.04%233.33%
Reiner Sailer32.29%116.67%
Arjan van de Ven10.76%116.67%
Total131100.00%6100.00%

static const struct file_operations tpm_bios_measurements_ops = { .owner = THIS_MODULE, .open = tpm_bios_measurements_open, .read = seq_read, .llseek = seq_lseek, .release = tpm_bios_measurements_release, };
static int tpm_read_log(struct tpm_chip *chip) { int rc; if (chip->log.bios_event_log != NULL) { dev_dbg(&chip->dev, "%s: ERROR - event log already initialized\n", __func__); return -EFAULT; } rc = tpm_read_log_acpi(chip); if (rc != -ENODEV) return rc; return tpm_read_log_of(chip); }

Contributors

PersonTokensPropCommitsCommitProp
Nayna Jain6295.38%150.00%
Jason Gunthorpe34.62%150.00%
Total65100.00%2100.00%

/* * tpm_bios_log_setup() - Read the event log from the firmware * @chip: TPM chip to use. * * If an event log is found then the securityfs files are setup to * export it to userspace, otherwise nothing is done. * * Returns -ENODEV if the firmware has no event log or securityfs is not * supported. */
int tpm_bios_log_setup(struct tpm_chip *chip) { const char *name = dev_name(&chip->dev); unsigned int cnt; int rc = 0; rc = tpm_read_log(chip); if (rc) return rc; cnt = 0; chip->bios_dir[cnt] = securityfs_create_dir(name, NULL); /* NOTE: securityfs_create_dir can return ENODEV if securityfs is * compiled out. The caller should ignore the ENODEV return code. */ if (IS_ERR(chip->bios_dir[cnt])) goto err; cnt++; chip->bin_log_seqops.chip = chip; if (chip->flags & TPM_CHIP_FLAG_TPM2) chip->bin_log_seqops.seqops = &tpm2_binary_b_measurements_seqops; else chip->bin_log_seqops.seqops = &tpm_binary_b_measurements_seqops; chip->bios_dir[cnt] = securityfs_create_file("binary_bios_measurements", 0440, chip->bios_dir[0], (void *)&chip->bin_log_seqops, &tpm_bios_measurements_ops); if (IS_ERR(chip->bios_dir[cnt])) goto err; cnt++; if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) { chip->ascii_log_seqops.chip = chip; chip->ascii_log_seqops.seqops = &tpm_ascii_b_measurements_seqops; chip->bios_dir[cnt] = securityfs_create_file("ascii_bios_measurements", 0440, chip->bios_dir[0], (void *)&chip->ascii_log_seqops, &tpm_bios_measurements_ops); if (IS_ERR(chip->bios_dir[cnt])) goto err; cnt++; } return 0; err: rc = PTR_ERR(chip->bios_dir[cnt]); chip->bios_dir[cnt] = NULL; tpm_bios_log_teardown(chip); return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Nayna Jain10436.62%550.00%
Jarkko Sakkinen9332.75%110.00%
Kylene Jo Hall6221.83%110.00%
Jason Gunthorpe144.93%220.00%
Andrew Morton113.87%110.00%
Total284100.00%10100.00%


void tpm_bios_log_teardown(struct tpm_chip *chip) { int i; struct inode *inode; /* securityfs_remove currently doesn't take care of handling sync * between removal and opening of pseudo files. To handle this, a * workaround is added by making i_private = NULL here during removal * and to check it during open(), both within inode_lock()/unlock(). * This design ensures that open() either safely gets kref or fails. */ for (i = (TPM_NUM_EVENT_LOG_FILES - 1); i >= 0; i--) { if (chip->bios_dir[i]) { inode = d_inode(chip->bios_dir[i]); inode_lock(inode); inode->i_private = NULL; inode_unlock(inode); securityfs_remove(chip->bios_dir[i]); } } }

Contributors

PersonTokensPropCommitsCommitProp
Nayna Jain3641.38%125.00%
Kylene Jo Hall2731.03%125.00%
Jarkko Sakkinen1314.94%125.00%
Stefan Berger1112.64%125.00%
Total87100.00%4100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Kylene Jo Hall111159.41%413.79%
Nayna Jain31116.63%620.69%
Hon Ching (Vicky) Lo1859.89%13.45%
Jarkko Sakkinen1065.67%13.45%
Harald Hoyer522.78%13.45%
Seiji Munetoh462.46%26.90%
Jason Gunthorpe180.96%310.34%
Andrew Morton140.75%26.90%
Stefan Berger110.59%13.45%
Reiner Sailer30.16%13.45%
Tejun Heo30.16%13.45%
Eric Paris20.11%13.45%
Arjan van de Ven20.11%13.45%
Kent Yoder20.11%13.45%
James Morris20.11%13.45%
Adrian Bunk10.05%13.45%
Andy Shevchenko10.05%13.45%
Total1870100.00%29100.00%
Directory: drivers/char/tpm
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