linux/drivers/acpi/acpi_fpdt.c
Vasily Khoruzhick a83c68a3bf ACPI: FPDT: properly handle invalid FPDT subtables
Buggy BIOSes may have invalid FPDT subtables, e.g. on my hardware:

S3PT subtable:

7F20FE30: 53 33 50 54 24 00 00 00-00 00 00 00 00 00 18 01  *S3PT$...........*
7F20FE40: 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00  *................*
7F20FE50: 00 00 00 00

Here the first record has zero length.

FBPT subtable:

7F20FE50:             46 42 50 54-3C 00 00 00 46 42 50 54  *....FBPT<...FBPT*
7F20FE60: 02 00 30 02 00 00 00 00-00 00 00 00 00 00 00 00  *..0.............*
7F20FE70: 2A A6 BC 6E 0B 00 00 00-1A 44 41 70 0B 00 00 00  **..n.....DAp....*
7F20FE80: 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00  *................*

And here FBPT table has FBPT signature repeated instead of the first
record.

Current code will be looping indefinitely due to zero length records, so
break out of the loop if record length is zero.

While we are here, add proper handling for fpdt_process_subtable()
failures.

Fixes: d1eb86e59b ("ACPI: tables: introduce support for FPDT table")
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
[ rjw: Comment edit, added empty code lines ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-10-03 21:12:22 +02:00

317 lines
7.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* FPDT support for exporting boot and suspend/resume performance data
*
* Copyright (C) 2021 Intel Corporation. All rights reserved.
*/
#define pr_fmt(fmt) "ACPI FPDT: " fmt
#include <linux/acpi.h>
/*
* FPDT contains ACPI table header and a number of fpdt_subtable_entries.
* Each fpdt_subtable_entry points to a subtable: FBPT or S3PT.
* Each FPDT subtable (FBPT/S3PT) is composed of a fpdt_subtable_header
* and a number of fpdt performance records.
* Each FPDT performance record is composed of a fpdt_record_header and
* performance data fields, for boot or suspend or resume phase.
*/
enum fpdt_subtable_type {
SUBTABLE_FBPT,
SUBTABLE_S3PT,
};
struct fpdt_subtable_entry {
u16 type; /* refer to enum fpdt_subtable_type */
u8 length;
u8 revision;
u32 reserved;
u64 address; /* physical address of the S3PT/FBPT table */
};
struct fpdt_subtable_header {
u32 signature;
u32 length;
};
enum fpdt_record_type {
RECORD_S3_RESUME,
RECORD_S3_SUSPEND,
RECORD_BOOT,
};
struct fpdt_record_header {
u16 type; /* refer to enum fpdt_record_type */
u8 length;
u8 revision;
};
struct resume_performance_record {
struct fpdt_record_header header;
u32 resume_count;
u64 resume_prev;
u64 resume_avg;
} __attribute__((packed));
struct boot_performance_record {
struct fpdt_record_header header;
u32 reserved;
u64 firmware_start;
u64 bootloader_load;
u64 bootloader_launch;
u64 exitbootservice_start;
u64 exitbootservice_end;
} __attribute__((packed));
struct suspend_performance_record {
struct fpdt_record_header header;
u64 suspend_start;
u64 suspend_end;
} __attribute__((packed));
static struct resume_performance_record *record_resume;
static struct suspend_performance_record *record_suspend;
static struct boot_performance_record *record_boot;
#define FPDT_ATTR(phase, name) \
static ssize_t name##_show(struct kobject *kobj, \
struct kobj_attribute *attr, char *buf) \
{ \
return sprintf(buf, "%llu\n", record_##phase->name); \
} \
static struct kobj_attribute name##_attr = \
__ATTR(name##_ns, 0444, name##_show, NULL)
FPDT_ATTR(resume, resume_prev);
FPDT_ATTR(resume, resume_avg);
FPDT_ATTR(suspend, suspend_start);
FPDT_ATTR(suspend, suspend_end);
FPDT_ATTR(boot, firmware_start);
FPDT_ATTR(boot, bootloader_load);
FPDT_ATTR(boot, bootloader_launch);
FPDT_ATTR(boot, exitbootservice_start);
FPDT_ATTR(boot, exitbootservice_end);
static ssize_t resume_count_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return sprintf(buf, "%u\n", record_resume->resume_count);
}
static struct kobj_attribute resume_count_attr =
__ATTR_RO(resume_count);
static struct attribute *resume_attrs[] = {
&resume_count_attr.attr,
&resume_prev_attr.attr,
&resume_avg_attr.attr,
NULL
};
static const struct attribute_group resume_attr_group = {
.attrs = resume_attrs,
.name = "resume",
};
static struct attribute *suspend_attrs[] = {
&suspend_start_attr.attr,
&suspend_end_attr.attr,
NULL
};
static const struct attribute_group suspend_attr_group = {
.attrs = suspend_attrs,
.name = "suspend",
};
static struct attribute *boot_attrs[] = {
&firmware_start_attr.attr,
&bootloader_load_attr.attr,
&bootloader_launch_attr.attr,
&exitbootservice_start_attr.attr,
&exitbootservice_end_attr.attr,
NULL
};
static const struct attribute_group boot_attr_group = {
.attrs = boot_attrs,
.name = "boot",
};
static struct kobject *fpdt_kobj;
#if defined CONFIG_X86 && defined CONFIG_PHYS_ADDR_T_64BIT
#include <linux/processor.h>
static bool fpdt_address_valid(u64 address)
{
/*
* On some systems the table contains invalid addresses
* with unsuppored high address bits set, check for this.
*/
return !(address >> boot_cpu_data.x86_phys_bits);
}
#else
static bool fpdt_address_valid(u64 address)
{
return true;
}
#endif
static int fpdt_process_subtable(u64 address, u32 subtable_type)
{
struct fpdt_subtable_header *subtable_header;
struct fpdt_record_header *record_header;
char *signature = (subtable_type == SUBTABLE_FBPT ? "FBPT" : "S3PT");
u32 length, offset;
int result;
if (!fpdt_address_valid(address)) {
pr_info(FW_BUG "invalid physical address: 0x%llx!\n", address);
return -EINVAL;
}
subtable_header = acpi_os_map_memory(address, sizeof(*subtable_header));
if (!subtable_header)
return -ENOMEM;
if (strncmp((char *)&subtable_header->signature, signature, 4)) {
pr_info(FW_BUG "subtable signature and type mismatch!\n");
return -EINVAL;
}
length = subtable_header->length;
acpi_os_unmap_memory(subtable_header, sizeof(*subtable_header));
subtable_header = acpi_os_map_memory(address, length);
if (!subtable_header)
return -ENOMEM;
offset = sizeof(*subtable_header);
while (offset < length) {
record_header = (void *)subtable_header + offset;
offset += record_header->length;
if (!record_header->length) {
pr_err(FW_BUG "Zero-length record found in FPTD.\n");
result = -EINVAL;
goto err;
}
switch (record_header->type) {
case RECORD_S3_RESUME:
if (subtable_type != SUBTABLE_S3PT) {
pr_err(FW_BUG "Invalid record %d for subtable %s\n",
record_header->type, signature);
result = -EINVAL;
goto err;
}
if (record_resume) {
pr_err("Duplicate resume performance record found.\n");
continue;
}
record_resume = (struct resume_performance_record *)record_header;
result = sysfs_create_group(fpdt_kobj, &resume_attr_group);
if (result)
goto err;
break;
case RECORD_S3_SUSPEND:
if (subtable_type != SUBTABLE_S3PT) {
pr_err(FW_BUG "Invalid %d for subtable %s\n",
record_header->type, signature);
continue;
}
if (record_suspend) {
pr_err("Duplicate suspend performance record found.\n");
continue;
}
record_suspend = (struct suspend_performance_record *)record_header;
result = sysfs_create_group(fpdt_kobj, &suspend_attr_group);
if (result)
goto err;
break;
case RECORD_BOOT:
if (subtable_type != SUBTABLE_FBPT) {
pr_err(FW_BUG "Invalid %d for subtable %s\n",
record_header->type, signature);
result = -EINVAL;
goto err;
}
if (record_boot) {
pr_err("Duplicate boot performance record found.\n");
continue;
}
record_boot = (struct boot_performance_record *)record_header;
result = sysfs_create_group(fpdt_kobj, &boot_attr_group);
if (result)
goto err;
break;
default:
/* Other types are reserved in ACPI 6.4 spec. */
break;
}
}
return 0;
err:
if (record_boot)
sysfs_remove_group(fpdt_kobj, &boot_attr_group);
if (record_suspend)
sysfs_remove_group(fpdt_kobj, &suspend_attr_group);
if (record_resume)
sysfs_remove_group(fpdt_kobj, &resume_attr_group);
return result;
}
static int __init acpi_init_fpdt(void)
{
acpi_status status;
struct acpi_table_header *header;
struct fpdt_subtable_entry *subtable;
u32 offset = sizeof(*header);
int result;
status = acpi_get_table(ACPI_SIG_FPDT, 0, &header);
if (ACPI_FAILURE(status))
return 0;
fpdt_kobj = kobject_create_and_add("fpdt", acpi_kobj);
if (!fpdt_kobj) {
result = -ENOMEM;
goto err_nomem;
}
while (offset < header->length) {
subtable = (void *)header + offset;
switch (subtable->type) {
case SUBTABLE_FBPT:
case SUBTABLE_S3PT:
result = fpdt_process_subtable(subtable->address,
subtable->type);
if (result)
goto err_subtable;
break;
default:
/* Other types are reserved in ACPI 6.4 spec. */
break;
}
offset += sizeof(*subtable);
}
return 0;
err_subtable:
kobject_put(fpdt_kobj);
err_nomem:
acpi_put_table(header);
return result;
}
fs_initcall(acpi_init_fpdt);