linux/drivers/firmware/dmi_scan.c
Jean Delvare 13a0ac816d firmware: dmi: Fortify entry point length checks
Ensure that the SMBIOS entry point is long enough to include all the
fields we need. Otherwise it is pointless to even attempt to verify
its checksum.

Also fix the maximum length check, which is technically 32, not 31.
It does not matter in practice as the only valid values are 31 (for
SMBIOS 2.x) and 24 (for SMBIOS 3.x), but let's still have the check
right in case new fields are added to either structure in the future.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/lkml/20220823094857.27f3d924@endymion.delvare/T/
2022-09-23 14:53:14 +02:00

1211 lines
29 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/types.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/dmi.h>
#include <linux/efi.h>
#include <linux/memblock.h>
#include <linux/random.h>
#include <asm/dmi.h>
#include <asm/unaligned.h>
#ifndef SMBIOS_ENTRY_POINT_SCAN_START
#define SMBIOS_ENTRY_POINT_SCAN_START 0xF0000
#endif
struct kobject *dmi_kobj;
EXPORT_SYMBOL_GPL(dmi_kobj);
/*
* DMI stands for "Desktop Management Interface". It is part
* of and an antecedent to, SMBIOS, which stands for System
* Management BIOS. See further: https://www.dmtf.org/standards
*/
static const char dmi_empty_string[] = "";
static u32 dmi_ver __initdata;
static u32 dmi_len;
static u16 dmi_num;
static u8 smbios_entry_point[32];
static int smbios_entry_point_size;
/* DMI system identification string used during boot */
static char dmi_ids_string[128] __initdata;
static struct dmi_memdev_info {
const char *device;
const char *bank;
u64 size; /* bytes */
u16 handle;
u8 type; /* DDR2, DDR3, DDR4 etc */
} *dmi_memdev;
static int dmi_memdev_nr;
static const char * __init dmi_string_nosave(const struct dmi_header *dm, u8 s)
{
const u8 *bp = ((u8 *) dm) + dm->length;
const u8 *nsp;
if (s) {
while (--s > 0 && *bp)
bp += strlen(bp) + 1;
/* Strings containing only spaces are considered empty */
nsp = bp;
while (*nsp == ' ')
nsp++;
if (*nsp != '\0')
return bp;
}
return dmi_empty_string;
}
static const char * __init dmi_string(const struct dmi_header *dm, u8 s)
{
const char *bp = dmi_string_nosave(dm, s);
char *str;
size_t len;
if (bp == dmi_empty_string)
return dmi_empty_string;
len = strlen(bp) + 1;
str = dmi_alloc(len);
if (str != NULL)
strcpy(str, bp);
return str;
}
/*
* We have to be cautious here. We have seen BIOSes with DMI pointers
* pointing to completely the wrong place for example
*/
static void dmi_decode_table(u8 *buf,
void (*decode)(const struct dmi_header *, void *),
void *private_data)
{
u8 *data = buf;
int i = 0;
/*
* Stop when we have seen all the items the table claimed to have
* (SMBIOS < 3.0 only) OR we reach an end-of-table marker (SMBIOS
* >= 3.0 only) OR we run off the end of the table (should never
* happen but sometimes does on bogus implementations.)
*/
while ((!dmi_num || i < dmi_num) &&
(data - buf + sizeof(struct dmi_header)) <= dmi_len) {
const struct dmi_header *dm = (const struct dmi_header *)data;
/*
* We want to know the total length (formatted area and
* strings) before decoding to make sure we won't run off the
* table in dmi_decode or dmi_string
*/
data += dm->length;
while ((data - buf < dmi_len - 1) && (data[0] || data[1]))
data++;
if (data - buf < dmi_len - 1)
decode(dm, private_data);
data += 2;
i++;
/*
* 7.45 End-of-Table (Type 127) [SMBIOS reference spec v3.0.0]
* For tables behind a 64-bit entry point, we have no item
* count and no exact table length, so stop on end-of-table
* marker. For tables behind a 32-bit entry point, we have
* seen OEM structures behind the end-of-table marker on
* some systems, so don't trust it.
*/
if (!dmi_num && dm->type == DMI_ENTRY_END_OF_TABLE)
break;
}
/* Trim DMI table length if needed */
if (dmi_len > data - buf)
dmi_len = data - buf;
}
static phys_addr_t dmi_base;
static int __init dmi_walk_early(void (*decode)(const struct dmi_header *,
void *))
{
u8 *buf;
u32 orig_dmi_len = dmi_len;
buf = dmi_early_remap(dmi_base, orig_dmi_len);
if (buf == NULL)
return -ENOMEM;
dmi_decode_table(buf, decode, NULL);
add_device_randomness(buf, dmi_len);
dmi_early_unmap(buf, orig_dmi_len);
return 0;
}
static int __init dmi_checksum(const u8 *buf, u8 len)
{
u8 sum = 0;
int a;
for (a = 0; a < len; a++)
sum += buf[a];
return sum == 0;
}
static const char *dmi_ident[DMI_STRING_MAX];
static LIST_HEAD(dmi_devices);
int dmi_available;
EXPORT_SYMBOL_GPL(dmi_available);
/*
* Save a DMI string
*/
static void __init dmi_save_ident(const struct dmi_header *dm, int slot,
int string)
{
const char *d = (const char *) dm;
const char *p;
if (dmi_ident[slot] || dm->length <= string)
return;
p = dmi_string(dm, d[string]);
if (p == NULL)
return;
dmi_ident[slot] = p;
}
static void __init dmi_save_release(const struct dmi_header *dm, int slot,
int index)
{
const u8 *minor, *major;
char *s;
/* If the table doesn't have the field, let's return */
if (dmi_ident[slot] || dm->length < index)
return;
minor = (u8 *) dm + index;
major = (u8 *) dm + index - 1;
/* As per the spec, if the system doesn't support this field,
* the value is FF
*/
if (*major == 0xFF && *minor == 0xFF)
return;
s = dmi_alloc(8);
if (!s)
return;
sprintf(s, "%u.%u", *major, *minor);
dmi_ident[slot] = s;
}
static void __init dmi_save_uuid(const struct dmi_header *dm, int slot,
int index)
{
const u8 *d;
char *s;
int is_ff = 1, is_00 = 1, i;
if (dmi_ident[slot] || dm->length < index + 16)
return;
d = (u8 *) dm + index;
for (i = 0; i < 16 && (is_ff || is_00); i++) {
if (d[i] != 0x00)
is_00 = 0;
if (d[i] != 0xFF)
is_ff = 0;
}
if (is_ff || is_00)
return;
s = dmi_alloc(16*2+4+1);
if (!s)
return;
/*
* As of version 2.6 of the SMBIOS specification, the first 3 fields of
* the UUID are supposed to be little-endian encoded. The specification
* says that this is the defacto standard.
*/
if (dmi_ver >= 0x020600)
sprintf(s, "%pUl", d);
else
sprintf(s, "%pUb", d);
dmi_ident[slot] = s;
}
static void __init dmi_save_type(const struct dmi_header *dm, int slot,
int index)
{
const u8 *d;
char *s;
if (dmi_ident[slot] || dm->length <= index)
return;
s = dmi_alloc(4);
if (!s)
return;
d = (u8 *) dm + index;
sprintf(s, "%u", *d & 0x7F);
dmi_ident[slot] = s;
}
static void __init dmi_save_one_device(int type, const char *name)
{
struct dmi_device *dev;
/* No duplicate device */
if (dmi_find_device(type, name, NULL))
return;
dev = dmi_alloc(sizeof(*dev) + strlen(name) + 1);
if (!dev)
return;
dev->type = type;
strcpy((char *)(dev + 1), name);
dev->name = (char *)(dev + 1);
dev->device_data = NULL;
list_add(&dev->list, &dmi_devices);
}
static void __init dmi_save_devices(const struct dmi_header *dm)
{
int i, count = (dm->length - sizeof(struct dmi_header)) / 2;
for (i = 0; i < count; i++) {
const char *d = (char *)(dm + 1) + (i * 2);
/* Skip disabled device */
if ((*d & 0x80) == 0)
continue;
dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d + 1)));
}
}
static void __init dmi_save_oem_strings_devices(const struct dmi_header *dm)
{
int i, count;
struct dmi_device *dev;
if (dm->length < 0x05)
return;
count = *(u8 *)(dm + 1);
for (i = 1; i <= count; i++) {
const char *devname = dmi_string(dm, i);
if (devname == dmi_empty_string)
continue;
dev = dmi_alloc(sizeof(*dev));
if (!dev)
break;
dev->type = DMI_DEV_TYPE_OEM_STRING;
dev->name = devname;
dev->device_data = NULL;
list_add(&dev->list, &dmi_devices);
}
}
static void __init dmi_save_ipmi_device(const struct dmi_header *dm)
{
struct dmi_device *dev;
void *data;
data = dmi_alloc(dm->length);
if (data == NULL)
return;
memcpy(data, dm, dm->length);
dev = dmi_alloc(sizeof(*dev));
if (!dev)
return;
dev->type = DMI_DEV_TYPE_IPMI;
dev->name = "IPMI controller";
dev->device_data = data;
list_add_tail(&dev->list, &dmi_devices);
}
static void __init dmi_save_dev_pciaddr(int instance, int segment, int bus,
int devfn, const char *name, int type)
{
struct dmi_dev_onboard *dev;
/* Ignore invalid values */
if (type == DMI_DEV_TYPE_DEV_SLOT &&
segment == 0xFFFF && bus == 0xFF && devfn == 0xFF)
return;
dev = dmi_alloc(sizeof(*dev) + strlen(name) + 1);
if (!dev)
return;
dev->instance = instance;
dev->segment = segment;
dev->bus = bus;
dev->devfn = devfn;
strcpy((char *)&dev[1], name);
dev->dev.type = type;
dev->dev.name = (char *)&dev[1];
dev->dev.device_data = dev;
list_add(&dev->dev.list, &dmi_devices);
}
static void __init dmi_save_extended_devices(const struct dmi_header *dm)
{
const char *name;
const u8 *d = (u8 *)dm;
if (dm->length < 0x0B)
return;
/* Skip disabled device */
if ((d[0x5] & 0x80) == 0)
return;
name = dmi_string_nosave(dm, d[0x4]);
dmi_save_dev_pciaddr(d[0x6], *(u16 *)(d + 0x7), d[0x9], d[0xA], name,
DMI_DEV_TYPE_DEV_ONBOARD);
dmi_save_one_device(d[0x5] & 0x7f, name);
}
static void __init dmi_save_system_slot(const struct dmi_header *dm)
{
const u8 *d = (u8 *)dm;
/* Need SMBIOS 2.6+ structure */
if (dm->length < 0x11)
return;
dmi_save_dev_pciaddr(*(u16 *)(d + 0x9), *(u16 *)(d + 0xD), d[0xF],
d[0x10], dmi_string_nosave(dm, d[0x4]),
DMI_DEV_TYPE_DEV_SLOT);
}
static void __init count_mem_devices(const struct dmi_header *dm, void *v)
{
if (dm->type != DMI_ENTRY_MEM_DEVICE)
return;
dmi_memdev_nr++;
}
static void __init save_mem_devices(const struct dmi_header *dm, void *v)
{
const char *d = (const char *)dm;
static int nr;
u64 bytes;
u16 size;
if (dm->type != DMI_ENTRY_MEM_DEVICE || dm->length < 0x13)
return;
if (nr >= dmi_memdev_nr) {
pr_warn(FW_BUG "Too many DIMM entries in SMBIOS table\n");
return;
}
dmi_memdev[nr].handle = get_unaligned(&dm->handle);
dmi_memdev[nr].device = dmi_string(dm, d[0x10]);
dmi_memdev[nr].bank = dmi_string(dm, d[0x11]);
dmi_memdev[nr].type = d[0x12];
size = get_unaligned((u16 *)&d[0xC]);
if (size == 0)
bytes = 0;
else if (size == 0xffff)
bytes = ~0ull;
else if (size & 0x8000)
bytes = (u64)(size & 0x7fff) << 10;
else if (size != 0x7fff || dm->length < 0x20)
bytes = (u64)size << 20;
else
bytes = (u64)get_unaligned((u32 *)&d[0x1C]) << 20;
dmi_memdev[nr].size = bytes;
nr++;
}
static void __init dmi_memdev_walk(void)
{
if (dmi_walk_early(count_mem_devices) == 0 && dmi_memdev_nr) {
dmi_memdev = dmi_alloc(sizeof(*dmi_memdev) * dmi_memdev_nr);
if (dmi_memdev)
dmi_walk_early(save_mem_devices);
}
}
/*
* Process a DMI table entry. Right now all we care about are the BIOS
* and machine entries. For 2.5 we should pull the smbus controller info
* out of here.
*/
static void __init dmi_decode(const struct dmi_header *dm, void *dummy)
{
switch (dm->type) {
case 0: /* BIOS Information */
dmi_save_ident(dm, DMI_BIOS_VENDOR, 4);
dmi_save_ident(dm, DMI_BIOS_VERSION, 5);
dmi_save_ident(dm, DMI_BIOS_DATE, 8);
dmi_save_release(dm, DMI_BIOS_RELEASE, 21);
dmi_save_release(dm, DMI_EC_FIRMWARE_RELEASE, 23);
break;
case 1: /* System Information */
dmi_save_ident(dm, DMI_SYS_VENDOR, 4);
dmi_save_ident(dm, DMI_PRODUCT_NAME, 5);
dmi_save_ident(dm, DMI_PRODUCT_VERSION, 6);
dmi_save_ident(dm, DMI_PRODUCT_SERIAL, 7);
dmi_save_uuid(dm, DMI_PRODUCT_UUID, 8);
dmi_save_ident(dm, DMI_PRODUCT_SKU, 25);
dmi_save_ident(dm, DMI_PRODUCT_FAMILY, 26);
break;
case 2: /* Base Board Information */
dmi_save_ident(dm, DMI_BOARD_VENDOR, 4);
dmi_save_ident(dm, DMI_BOARD_NAME, 5);
dmi_save_ident(dm, DMI_BOARD_VERSION, 6);
dmi_save_ident(dm, DMI_BOARD_SERIAL, 7);
dmi_save_ident(dm, DMI_BOARD_ASSET_TAG, 8);
break;
case 3: /* Chassis Information */
dmi_save_ident(dm, DMI_CHASSIS_VENDOR, 4);
dmi_save_type(dm, DMI_CHASSIS_TYPE, 5);
dmi_save_ident(dm, DMI_CHASSIS_VERSION, 6);
dmi_save_ident(dm, DMI_CHASSIS_SERIAL, 7);
dmi_save_ident(dm, DMI_CHASSIS_ASSET_TAG, 8);
break;
case 9: /* System Slots */
dmi_save_system_slot(dm);
break;
case 10: /* Onboard Devices Information */
dmi_save_devices(dm);
break;
case 11: /* OEM Strings */
dmi_save_oem_strings_devices(dm);
break;
case 38: /* IPMI Device Information */
dmi_save_ipmi_device(dm);
break;
case 41: /* Onboard Devices Extended Information */
dmi_save_extended_devices(dm);
}
}
static int __init print_filtered(char *buf, size_t len, const char *info)
{
int c = 0;
const char *p;
if (!info)
return c;
for (p = info; *p; p++)
if (isprint(*p))
c += scnprintf(buf + c, len - c, "%c", *p);
else
c += scnprintf(buf + c, len - c, "\\x%02x", *p & 0xff);
return c;
}
static void __init dmi_format_ids(char *buf, size_t len)
{
int c = 0;
const char *board; /* Board Name is optional */
c += print_filtered(buf + c, len - c,
dmi_get_system_info(DMI_SYS_VENDOR));
c += scnprintf(buf + c, len - c, " ");
c += print_filtered(buf + c, len - c,
dmi_get_system_info(DMI_PRODUCT_NAME));
board = dmi_get_system_info(DMI_BOARD_NAME);
if (board) {
c += scnprintf(buf + c, len - c, "/");
c += print_filtered(buf + c, len - c, board);
}
c += scnprintf(buf + c, len - c, ", BIOS ");
c += print_filtered(buf + c, len - c,
dmi_get_system_info(DMI_BIOS_VERSION));
c += scnprintf(buf + c, len - c, " ");
c += print_filtered(buf + c, len - c,
dmi_get_system_info(DMI_BIOS_DATE));
}
/*
* Check for DMI/SMBIOS headers in the system firmware image. Any
* SMBIOS header must start 16 bytes before the DMI header, so take a
* 32 byte buffer and check for DMI at offset 16 and SMBIOS at offset
* 0. If the DMI header is present, set dmi_ver accordingly (SMBIOS
* takes precedence) and return 0. Otherwise return 1.
*/
static int __init dmi_present(const u8 *buf)
{
u32 smbios_ver;
/*
* The size of this structure is 31 bytes, but we also accept value
* 30 due to a mistake in SMBIOS specification version 2.1.
*/
if (memcmp(buf, "_SM_", 4) == 0 &&
buf[5] >= 30 && buf[5] <= 32 &&
dmi_checksum(buf, buf[5])) {
smbios_ver = get_unaligned_be16(buf + 6);
smbios_entry_point_size = buf[5];
memcpy(smbios_entry_point, buf, smbios_entry_point_size);
/* Some BIOS report weird SMBIOS version, fix that up */
switch (smbios_ver) {
case 0x021F:
case 0x0221:
pr_debug("SMBIOS version fixup (2.%d->2.%d)\n",
smbios_ver & 0xFF, 3);
smbios_ver = 0x0203;
break;
case 0x0233:
pr_debug("SMBIOS version fixup (2.%d->2.%d)\n", 51, 6);
smbios_ver = 0x0206;
break;
}
} else {
smbios_ver = 0;
}
buf += 16;
if (memcmp(buf, "_DMI_", 5) == 0 && dmi_checksum(buf, 15)) {
if (smbios_ver)
dmi_ver = smbios_ver;
else
dmi_ver = (buf[14] & 0xF0) << 4 | (buf[14] & 0x0F);
dmi_ver <<= 8;
dmi_num = get_unaligned_le16(buf + 12);
dmi_len = get_unaligned_le16(buf + 6);
dmi_base = get_unaligned_le32(buf + 8);
if (dmi_walk_early(dmi_decode) == 0) {
if (smbios_ver) {
pr_info("SMBIOS %d.%d present.\n",
dmi_ver >> 16, (dmi_ver >> 8) & 0xFF);
} else {
smbios_entry_point_size = 15;
memcpy(smbios_entry_point, buf,
smbios_entry_point_size);
pr_info("Legacy DMI %d.%d present.\n",
dmi_ver >> 16, (dmi_ver >> 8) & 0xFF);
}
dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
pr_info("DMI: %s\n", dmi_ids_string);
return 0;
}
}
return 1;
}
/*
* Check for the SMBIOS 3.0 64-bit entry point signature. Unlike the legacy
* 32-bit entry point, there is no embedded DMI header (_DMI_) in here.
*/
static int __init dmi_smbios3_present(const u8 *buf)
{
if (memcmp(buf, "_SM3_", 5) == 0 &&
buf[6] >= 24 && buf[6] <= 32 &&
dmi_checksum(buf, buf[6])) {
dmi_ver = get_unaligned_be24(buf + 7);
dmi_num = 0; /* No longer specified */
dmi_len = get_unaligned_le32(buf + 12);
dmi_base = get_unaligned_le64(buf + 16);
smbios_entry_point_size = buf[6];
memcpy(smbios_entry_point, buf, smbios_entry_point_size);
if (dmi_walk_early(dmi_decode) == 0) {
pr_info("SMBIOS %d.%d.%d present.\n",
dmi_ver >> 16, (dmi_ver >> 8) & 0xFF,
dmi_ver & 0xFF);
dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
pr_info("DMI: %s\n", dmi_ids_string);
return 0;
}
}
return 1;
}
static void __init dmi_scan_machine(void)
{
char __iomem *p, *q;
char buf[32];
if (efi_enabled(EFI_CONFIG_TABLES)) {
/*
* According to the DMTF SMBIOS reference spec v3.0.0, it is
* allowed to define both the 64-bit entry point (smbios3) and
* the 32-bit entry point (smbios), in which case they should
* either both point to the same SMBIOS structure table, or the
* table pointed to by the 64-bit entry point should contain a
* superset of the table contents pointed to by the 32-bit entry
* point (section 5.2)
* This implies that the 64-bit entry point should have
* precedence if it is defined and supported by the OS. If we
* have the 64-bit entry point, but fail to decode it, fall
* back to the legacy one (if available)
*/
if (efi.smbios3 != EFI_INVALID_TABLE_ADDR) {
p = dmi_early_remap(efi.smbios3, 32);
if (p == NULL)
goto error;
memcpy_fromio(buf, p, 32);
dmi_early_unmap(p, 32);
if (!dmi_smbios3_present(buf)) {
dmi_available = 1;
return;
}
}
if (efi.smbios == EFI_INVALID_TABLE_ADDR)
goto error;
/* This is called as a core_initcall() because it isn't
* needed during early boot. This also means we can
* iounmap the space when we're done with it.
*/
p = dmi_early_remap(efi.smbios, 32);
if (p == NULL)
goto error;
memcpy_fromio(buf, p, 32);
dmi_early_unmap(p, 32);
if (!dmi_present(buf)) {
dmi_available = 1;
return;
}
} else if (IS_ENABLED(CONFIG_DMI_SCAN_MACHINE_NON_EFI_FALLBACK)) {
p = dmi_early_remap(SMBIOS_ENTRY_POINT_SCAN_START, 0x10000);
if (p == NULL)
goto error;
/*
* Same logic as above, look for a 64-bit entry point
* first, and if not found, fall back to 32-bit entry point.
*/
memcpy_fromio(buf, p, 16);
for (q = p + 16; q < p + 0x10000; q += 16) {
memcpy_fromio(buf + 16, q, 16);
if (!dmi_smbios3_present(buf)) {
dmi_available = 1;
dmi_early_unmap(p, 0x10000);
return;
}
memcpy(buf, buf + 16, 16);
}
/*
* Iterate over all possible DMI header addresses q.
* Maintain the 32 bytes around q in buf. On the
* first iteration, substitute zero for the
* out-of-range bytes so there is no chance of falsely
* detecting an SMBIOS header.
*/
memset(buf, 0, 16);
for (q = p; q < p + 0x10000; q += 16) {
memcpy_fromio(buf + 16, q, 16);
if (!dmi_present(buf)) {
dmi_available = 1;
dmi_early_unmap(p, 0x10000);
return;
}
memcpy(buf, buf + 16, 16);
}
dmi_early_unmap(p, 0x10000);
}
error:
pr_info("DMI not present or invalid.\n");
}
static ssize_t raw_table_read(struct file *file, struct kobject *kobj,
struct bin_attribute *attr, char *buf,
loff_t pos, size_t count)
{
memcpy(buf, attr->private + pos, count);
return count;
}
static BIN_ATTR(smbios_entry_point, S_IRUSR, raw_table_read, NULL, 0);
static BIN_ATTR(DMI, S_IRUSR, raw_table_read, NULL, 0);
static int __init dmi_init(void)
{
struct kobject *tables_kobj;
u8 *dmi_table;
int ret = -ENOMEM;
if (!dmi_available)
return 0;
/*
* Set up dmi directory at /sys/firmware/dmi. This entry should stay
* even after farther error, as it can be used by other modules like
* dmi-sysfs.
*/
dmi_kobj = kobject_create_and_add("dmi", firmware_kobj);
if (!dmi_kobj)
goto err;
tables_kobj = kobject_create_and_add("tables", dmi_kobj);
if (!tables_kobj)
goto err;
dmi_table = dmi_remap(dmi_base, dmi_len);
if (!dmi_table)
goto err_tables;
bin_attr_smbios_entry_point.size = smbios_entry_point_size;
bin_attr_smbios_entry_point.private = smbios_entry_point;
ret = sysfs_create_bin_file(tables_kobj, &bin_attr_smbios_entry_point);
if (ret)
goto err_unmap;
bin_attr_DMI.size = dmi_len;
bin_attr_DMI.private = dmi_table;
ret = sysfs_create_bin_file(tables_kobj, &bin_attr_DMI);
if (!ret)
return 0;
sysfs_remove_bin_file(tables_kobj,
&bin_attr_smbios_entry_point);
err_unmap:
dmi_unmap(dmi_table);
err_tables:
kobject_del(tables_kobj);
kobject_put(tables_kobj);
err:
pr_err("dmi: Firmware registration failed.\n");
return ret;
}
subsys_initcall(dmi_init);
/**
* dmi_setup - scan and setup DMI system information
*
* Scan the DMI system information. This setups DMI identifiers
* (dmi_system_id) for printing it out on task dumps and prepares
* DIMM entry information (dmi_memdev_info) from the SMBIOS table
* for using this when reporting memory errors.
*/
void __init dmi_setup(void)
{
dmi_scan_machine();
if (!dmi_available)
return;
dmi_memdev_walk();
dump_stack_set_arch_desc("%s", dmi_ids_string);
}
/**
* dmi_matches - check if dmi_system_id structure matches system DMI data
* @dmi: pointer to the dmi_system_id structure to check
*/
static bool dmi_matches(const struct dmi_system_id *dmi)
{
int i;
for (i = 0; i < ARRAY_SIZE(dmi->matches); i++) {
int s = dmi->matches[i].slot;
if (s == DMI_NONE)
break;
if (s == DMI_OEM_STRING) {
/* DMI_OEM_STRING must be exact match */
const struct dmi_device *valid;
valid = dmi_find_device(DMI_DEV_TYPE_OEM_STRING,
dmi->matches[i].substr, NULL);
if (valid)
continue;
} else if (dmi_ident[s]) {
if (dmi->matches[i].exact_match) {
if (!strcmp(dmi_ident[s],
dmi->matches[i].substr))
continue;
} else {
if (strstr(dmi_ident[s],
dmi->matches[i].substr))
continue;
}
}
/* No match */
return false;
}
return true;
}
/**
* dmi_is_end_of_table - check for end-of-table marker
* @dmi: pointer to the dmi_system_id structure to check
*/
static bool dmi_is_end_of_table(const struct dmi_system_id *dmi)
{
return dmi->matches[0].slot == DMI_NONE;
}
/**
* dmi_check_system - check system DMI data
* @list: array of dmi_system_id structures to match against
* All non-null elements of the list must match
* their slot's (field index's) data (i.e., each
* list string must be a substring of the specified
* DMI slot's string data) to be considered a
* successful match.
*
* Walk the blacklist table running matching functions until someone
* returns non zero or we hit the end. Callback function is called for
* each successful match. Returns the number of matches.
*
* dmi_setup must be called before this function is called.
*/
int dmi_check_system(const struct dmi_system_id *list)
{
int count = 0;
const struct dmi_system_id *d;
for (d = list; !dmi_is_end_of_table(d); d++)
if (dmi_matches(d)) {
count++;
if (d->callback && d->callback(d))
break;
}
return count;
}
EXPORT_SYMBOL(dmi_check_system);
/**
* dmi_first_match - find dmi_system_id structure matching system DMI data
* @list: array of dmi_system_id structures to match against
* All non-null elements of the list must match
* their slot's (field index's) data (i.e., each
* list string must be a substring of the specified
* DMI slot's string data) to be considered a
* successful match.
*
* Walk the blacklist table until the first match is found. Return the
* pointer to the matching entry or NULL if there's no match.
*
* dmi_setup must be called before this function is called.
*/
const struct dmi_system_id *dmi_first_match(const struct dmi_system_id *list)
{
const struct dmi_system_id *d;
for (d = list; !dmi_is_end_of_table(d); d++)
if (dmi_matches(d))
return d;
return NULL;
}
EXPORT_SYMBOL(dmi_first_match);
/**
* dmi_get_system_info - return DMI data value
* @field: data index (see enum dmi_field)
*
* Returns one DMI data value, can be used to perform
* complex DMI data checks.
*/
const char *dmi_get_system_info(int field)
{
return dmi_ident[field];
}
EXPORT_SYMBOL(dmi_get_system_info);
/**
* dmi_name_in_serial - Check if string is in the DMI product serial information
* @str: string to check for
*/
int dmi_name_in_serial(const char *str)
{
int f = DMI_PRODUCT_SERIAL;
if (dmi_ident[f] && strstr(dmi_ident[f], str))
return 1;
return 0;
}
/**
* dmi_name_in_vendors - Check if string is in the DMI system or board vendor name
* @str: Case sensitive Name
*/
int dmi_name_in_vendors(const char *str)
{
static int fields[] = { DMI_SYS_VENDOR, DMI_BOARD_VENDOR, DMI_NONE };
int i;
for (i = 0; fields[i] != DMI_NONE; i++) {
int f = fields[i];
if (dmi_ident[f] && strstr(dmi_ident[f], str))
return 1;
}
return 0;
}
EXPORT_SYMBOL(dmi_name_in_vendors);
/**
* dmi_find_device - find onboard device by type/name
* @type: device type or %DMI_DEV_TYPE_ANY to match all device types
* @name: device name string or %NULL to match all
* @from: previous device found in search, or %NULL for new search.
*
* Iterates through the list of known onboard devices. If a device is
* found with a matching @type and @name, a pointer to its device
* structure is returned. Otherwise, %NULL is returned.
* A new search is initiated by passing %NULL as the @from argument.
* If @from is not %NULL, searches continue from next device.
*/
const struct dmi_device *dmi_find_device(int type, const char *name,
const struct dmi_device *from)
{
const struct list_head *head = from ? &from->list : &dmi_devices;
struct list_head *d;
for (d = head->next; d != &dmi_devices; d = d->next) {
const struct dmi_device *dev =
list_entry(d, struct dmi_device, list);
if (((type == DMI_DEV_TYPE_ANY) || (dev->type == type)) &&
((name == NULL) || (strcmp(dev->name, name) == 0)))
return dev;
}
return NULL;
}
EXPORT_SYMBOL(dmi_find_device);
/**
* dmi_get_date - parse a DMI date
* @field: data index (see enum dmi_field)
* @yearp: optional out parameter for the year
* @monthp: optional out parameter for the month
* @dayp: optional out parameter for the day
*
* The date field is assumed to be in the form resembling
* [mm[/dd]]/yy[yy] and the result is stored in the out
* parameters any or all of which can be omitted.
*
* If the field doesn't exist, all out parameters are set to zero
* and false is returned. Otherwise, true is returned with any
* invalid part of date set to zero.
*
* On return, year, month and day are guaranteed to be in the
* range of [0,9999], [0,12] and [0,31] respectively.
*/
bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp)
{
int year = 0, month = 0, day = 0;
bool exists;
const char *s, *y;
char *e;
s = dmi_get_system_info(field);
exists = s;
if (!exists)
goto out;
/*
* Determine year first. We assume the date string resembles
* mm/dd/yy[yy] but the original code extracted only the year
* from the end. Keep the behavior in the spirit of no
* surprises.
*/
y = strrchr(s, '/');
if (!y)
goto out;
y++;
year = simple_strtoul(y, &e, 10);
if (y != e && year < 100) { /* 2-digit year */
year += 1900;
if (year < 1996) /* no dates < spec 1.0 */
year += 100;
}
if (year > 9999) /* year should fit in %04d */
year = 0;
/* parse the mm and dd */
month = simple_strtoul(s, &e, 10);
if (s == e || *e != '/' || !month || month > 12) {
month = 0;
goto out;
}
s = e + 1;
day = simple_strtoul(s, &e, 10);
if (s == y || s == e || *e != '/' || day > 31)
day = 0;
out:
if (yearp)
*yearp = year;
if (monthp)
*monthp = month;
if (dayp)
*dayp = day;
return exists;
}
EXPORT_SYMBOL(dmi_get_date);
/**
* dmi_get_bios_year - get a year out of DMI_BIOS_DATE field
*
* Returns year on success, -ENXIO if DMI is not selected,
* or a different negative error code if DMI field is not present
* or not parseable.
*/
int dmi_get_bios_year(void)
{
bool exists;
int year;
exists = dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL);
if (!exists)
return -ENODATA;
return year ? year : -ERANGE;
}
EXPORT_SYMBOL(dmi_get_bios_year);
/**
* dmi_walk - Walk the DMI table and get called back for every record
* @decode: Callback function
* @private_data: Private data to be passed to the callback function
*
* Returns 0 on success, -ENXIO if DMI is not selected or not present,
* or a different negative error code if DMI walking fails.
*/
int dmi_walk(void (*decode)(const struct dmi_header *, void *),
void *private_data)
{
u8 *buf;
if (!dmi_available)
return -ENXIO;
buf = dmi_remap(dmi_base, dmi_len);
if (buf == NULL)
return -ENOMEM;
dmi_decode_table(buf, decode, private_data);
dmi_unmap(buf);
return 0;
}
EXPORT_SYMBOL_GPL(dmi_walk);
/**
* dmi_match - compare a string to the dmi field (if exists)
* @f: DMI field identifier
* @str: string to compare the DMI field to
*
* Returns true if the requested field equals to the str (including NULL).
*/
bool dmi_match(enum dmi_field f, const char *str)
{
const char *info = dmi_get_system_info(f);
if (info == NULL || str == NULL)
return info == str;
return !strcmp(info, str);
}
EXPORT_SYMBOL_GPL(dmi_match);
void dmi_memdev_name(u16 handle, const char **bank, const char **device)
{
int n;
if (dmi_memdev == NULL)
return;
for (n = 0; n < dmi_memdev_nr; n++) {
if (handle == dmi_memdev[n].handle) {
*bank = dmi_memdev[n].bank;
*device = dmi_memdev[n].device;
break;
}
}
}
EXPORT_SYMBOL_GPL(dmi_memdev_name);
u64 dmi_memdev_size(u16 handle)
{
int n;
if (dmi_memdev) {
for (n = 0; n < dmi_memdev_nr; n++) {
if (handle == dmi_memdev[n].handle)
return dmi_memdev[n].size;
}
}
return ~0ull;
}
EXPORT_SYMBOL_GPL(dmi_memdev_size);
/**
* dmi_memdev_type - get the memory type
* @handle: DMI structure handle
*
* Return the DMI memory type of the module in the slot associated with the
* given DMI handle, or 0x0 if no such DMI handle exists.
*/
u8 dmi_memdev_type(u16 handle)
{
int n;
if (dmi_memdev) {
for (n = 0; n < dmi_memdev_nr; n++) {
if (handle == dmi_memdev[n].handle)
return dmi_memdev[n].type;
}
}
return 0x0; /* Not a valid value */
}
EXPORT_SYMBOL_GPL(dmi_memdev_type);
/**
* dmi_memdev_handle - get the DMI handle of a memory slot
* @slot: slot number
*
* Return the DMI handle associated with a given memory slot, or %0xFFFF
* if there is no such slot.
*/
u16 dmi_memdev_handle(int slot)
{
if (dmi_memdev && slot >= 0 && slot < dmi_memdev_nr)
return dmi_memdev[slot].handle;
return 0xffff; /* Not a valid value */
}
EXPORT_SYMBOL_GPL(dmi_memdev_handle);