linux_dsm_epyc7002/drivers/acpi/acpica/utids.c
Gustavo A. R. Silva 10cfde5dc6 ACPICA: Replace one-element array with flexible-array
ACPICA commit 7ba2f3d91a32f104765961fda0ed78b884ae193d

The current codebase makes use of one-element arrays in the following
form:

struct something {
    int length;
    u8 data[1];
};

struct something *instance;

instance = kmalloc(sizeof(*instance) + size, GFP_KERNEL);
instance->length = size;
memcpy(instance->data, source, size);

but the preferred mechanism to declare variable-length types such as
these ones is a flexible array member[1][2], introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure,
which will help us prevent some kind of undefined behavior bugs from
being inadvertently introduced[3] to the linux codebase from now on.

This issue was found with the help of Coccinelle and audited _manually_.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Link: https://github.com/acpica/acpica/commit/7ba2f3d9
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Erik Kaneda <erik.kaneda@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-27 14:55:42 +02:00

403 lines
11 KiB
C

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
*
* Module Name: utids - support for device Ids - HID, UID, CID, SUB, CLS
*
* Copyright (C) 2000 - 2020, Intel Corp.
*
*****************************************************************************/
#include <acpi/acpi.h>
#include "accommon.h"
#include "acinterp.h"
#define _COMPONENT ACPI_UTILITIES
ACPI_MODULE_NAME("utids")
/*******************************************************************************
*
* FUNCTION: acpi_ut_execute_HID
*
* PARAMETERS: device_node - Node for the device
* return_id - Where the string HID is returned
*
* RETURN: Status
*
* DESCRIPTION: Executes the _HID control method that returns the hardware
* ID of the device. The HID is either an 32-bit encoded EISAID
* Integer or a String. A string is always returned. An EISAID
* is converted to a string.
*
* NOTE: Internal function, no parameter validation
*
******************************************************************************/
acpi_status
acpi_ut_execute_HID(struct acpi_namespace_node *device_node,
struct acpi_pnp_device_id **return_id)
{
union acpi_operand_object *obj_desc;
struct acpi_pnp_device_id *hid;
u32 length;
acpi_status status;
ACPI_FUNCTION_TRACE(ut_execute_HID);
status = acpi_ut_evaluate_object(device_node, METHOD_NAME__HID,
ACPI_BTYPE_INTEGER | ACPI_BTYPE_STRING,
&obj_desc);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Get the size of the String to be returned, includes null terminator */
if (obj_desc->common.type == ACPI_TYPE_INTEGER) {
length = ACPI_EISAID_STRING_SIZE;
} else {
length = obj_desc->string.length + 1;
}
/* Allocate a buffer for the HID */
hid =
ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_pnp_device_id) +
(acpi_size)length);
if (!hid) {
status = AE_NO_MEMORY;
goto cleanup;
}
/* Area for the string starts after PNP_DEVICE_ID struct */
hid->string =
ACPI_ADD_PTR(char, hid, sizeof(struct acpi_pnp_device_id));
/* Convert EISAID to a string or simply copy existing string */
if (obj_desc->common.type == ACPI_TYPE_INTEGER) {
acpi_ex_eisa_id_to_string(hid->string, obj_desc->integer.value);
} else {
strcpy(hid->string, obj_desc->string.pointer);
}
hid->length = length;
*return_id = hid;
cleanup:
/* On exit, we must delete the return object */
acpi_ut_remove_reference(obj_desc);
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ut_execute_UID
*
* PARAMETERS: device_node - Node for the device
* return_id - Where the string UID is returned
*
* RETURN: Status
*
* DESCRIPTION: Executes the _UID control method that returns the unique
* ID of the device. The UID is either a 64-bit Integer (NOT an
* EISAID) or a string. Always returns a string. A 64-bit integer
* is converted to a decimal string.
*
* NOTE: Internal function, no parameter validation
*
******************************************************************************/
acpi_status
acpi_ut_execute_UID(struct acpi_namespace_node *device_node,
struct acpi_pnp_device_id **return_id)
{
union acpi_operand_object *obj_desc;
struct acpi_pnp_device_id *uid;
u32 length;
acpi_status status;
ACPI_FUNCTION_TRACE(ut_execute_UID);
status = acpi_ut_evaluate_object(device_node, METHOD_NAME__UID,
ACPI_BTYPE_INTEGER | ACPI_BTYPE_STRING,
&obj_desc);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Get the size of the String to be returned, includes null terminator */
if (obj_desc->common.type == ACPI_TYPE_INTEGER) {
length = ACPI_MAX64_DECIMAL_DIGITS + 1;
} else {
length = obj_desc->string.length + 1;
}
/* Allocate a buffer for the UID */
uid =
ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_pnp_device_id) +
(acpi_size)length);
if (!uid) {
status = AE_NO_MEMORY;
goto cleanup;
}
/* Area for the string starts after PNP_DEVICE_ID struct */
uid->string =
ACPI_ADD_PTR(char, uid, sizeof(struct acpi_pnp_device_id));
/* Convert an Integer to string, or just copy an existing string */
if (obj_desc->common.type == ACPI_TYPE_INTEGER) {
acpi_ex_integer_to_string(uid->string, obj_desc->integer.value);
} else {
strcpy(uid->string, obj_desc->string.pointer);
}
uid->length = length;
*return_id = uid;
cleanup:
/* On exit, we must delete the return object */
acpi_ut_remove_reference(obj_desc);
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ut_execute_CID
*
* PARAMETERS: device_node - Node for the device
* return_cid_list - Where the CID list is returned
*
* RETURN: Status, list of CID strings
*
* DESCRIPTION: Executes the _CID control method that returns one or more
* compatible hardware IDs for the device.
*
* NOTE: Internal function, no parameter validation
*
* A _CID method can return either a single compatible ID or a package of
* compatible IDs. Each compatible ID can be one of the following:
* 1) Integer (32 bit compressed EISA ID) or
* 2) String (PCI ID format, e.g. "PCI\VEN_vvvv&DEV_dddd&SUBSYS_ssssssss")
*
* The Integer CIDs are converted to string format by this function.
*
******************************************************************************/
acpi_status
acpi_ut_execute_CID(struct acpi_namespace_node *device_node,
struct acpi_pnp_device_id_list **return_cid_list)
{
union acpi_operand_object **cid_objects;
union acpi_operand_object *obj_desc;
struct acpi_pnp_device_id_list *cid_list;
char *next_id_string;
u32 string_area_size;
u32 length;
u32 cid_list_size;
acpi_status status;
u32 count;
u32 i;
ACPI_FUNCTION_TRACE(ut_execute_CID);
/* Evaluate the _CID method for this device */
status = acpi_ut_evaluate_object(device_node, METHOD_NAME__CID,
ACPI_BTYPE_INTEGER | ACPI_BTYPE_STRING
| ACPI_BTYPE_PACKAGE, &obj_desc);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/*
* Get the count and size of the returned _CIDs. _CID can return either
* a Package of Integers/Strings or a single Integer or String.
* Note: This section also validates that all CID elements are of the
* correct type (Integer or String).
*/
if (obj_desc->common.type == ACPI_TYPE_PACKAGE) {
count = obj_desc->package.count;
cid_objects = obj_desc->package.elements;
} else { /* Single Integer or String CID */
count = 1;
cid_objects = &obj_desc;
}
string_area_size = 0;
for (i = 0; i < count; i++) {
/* String lengths include null terminator */
switch (cid_objects[i]->common.type) {
case ACPI_TYPE_INTEGER:
string_area_size += ACPI_EISAID_STRING_SIZE;
break;
case ACPI_TYPE_STRING:
string_area_size += cid_objects[i]->string.length + 1;
break;
default:
status = AE_TYPE;
goto cleanup;
}
}
/*
* Now that we know the length of the CIDs, allocate return buffer:
* 1) Size of the base structure +
* 2) Size of the CID PNP_DEVICE_ID array +
* 3) Size of the actual CID strings
*/
cid_list_size = sizeof(struct acpi_pnp_device_id_list) +
(count * sizeof(struct acpi_pnp_device_id)) + string_area_size;
cid_list = ACPI_ALLOCATE_ZEROED(cid_list_size);
if (!cid_list) {
status = AE_NO_MEMORY;
goto cleanup;
}
/* Area for CID strings starts after the CID PNP_DEVICE_ID array */
next_id_string = ACPI_CAST_PTR(char, cid_list->ids) +
((acpi_size)count * sizeof(struct acpi_pnp_device_id));
/* Copy/convert the CIDs to the return buffer */
for (i = 0; i < count; i++) {
if (cid_objects[i]->common.type == ACPI_TYPE_INTEGER) {
/* Convert the Integer (EISAID) CID to a string */
acpi_ex_eisa_id_to_string(next_id_string,
cid_objects[i]->integer.
value);
length = ACPI_EISAID_STRING_SIZE;
} else { /* ACPI_TYPE_STRING */
/* Copy the String CID from the returned object */
strcpy(next_id_string, cid_objects[i]->string.pointer);
length = cid_objects[i]->string.length + 1;
}
cid_list->ids[i].string = next_id_string;
cid_list->ids[i].length = length;
next_id_string += length;
}
/* Finish the CID list */
cid_list->count = count;
cid_list->list_size = cid_list_size;
*return_cid_list = cid_list;
cleanup:
/* On exit, we must delete the _CID return object */
acpi_ut_remove_reference(obj_desc);
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ut_execute_CLS
*
* PARAMETERS: device_node - Node for the device
* return_id - Where the _CLS is returned
*
* RETURN: Status
*
* DESCRIPTION: Executes the _CLS control method that returns PCI-defined
* class code of the device. The _CLS value is always a package
* containing PCI class information as a list of integers.
* The returned string has format "BBSSPP", where:
* BB = Base-class code
* SS = Sub-class code
* PP = Programming Interface code
*
******************************************************************************/
acpi_status
acpi_ut_execute_CLS(struct acpi_namespace_node *device_node,
struct acpi_pnp_device_id **return_id)
{
union acpi_operand_object *obj_desc;
union acpi_operand_object **cls_objects;
u32 count;
struct acpi_pnp_device_id *cls;
u32 length;
acpi_status status;
u8 class_code[3] = { 0, 0, 0 };
ACPI_FUNCTION_TRACE(ut_execute_CLS);
status = acpi_ut_evaluate_object(device_node, METHOD_NAME__CLS,
ACPI_BTYPE_PACKAGE, &obj_desc);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Get the size of the String to be returned, includes null terminator */
length = ACPI_PCICLS_STRING_SIZE;
cls_objects = obj_desc->package.elements;
count = obj_desc->package.count;
if (obj_desc->common.type == ACPI_TYPE_PACKAGE) {
if (count > 0
&& cls_objects[0]->common.type == ACPI_TYPE_INTEGER) {
class_code[0] = (u8)cls_objects[0]->integer.value;
}
if (count > 1
&& cls_objects[1]->common.type == ACPI_TYPE_INTEGER) {
class_code[1] = (u8)cls_objects[1]->integer.value;
}
if (count > 2
&& cls_objects[2]->common.type == ACPI_TYPE_INTEGER) {
class_code[2] = (u8)cls_objects[2]->integer.value;
}
}
/* Allocate a buffer for the CLS */
cls =
ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_pnp_device_id) +
(acpi_size)length);
if (!cls) {
status = AE_NO_MEMORY;
goto cleanup;
}
/* Area for the string starts after PNP_DEVICE_ID struct */
cls->string =
ACPI_ADD_PTR(char, cls, sizeof(struct acpi_pnp_device_id));
/* Simply copy existing string */
acpi_ex_pci_cls_to_string(cls->string, class_code);
cls->length = length;
*return_id = cls;
cleanup:
/* On exit, we must delete the return object */
acpi_ut_remove_reference(obj_desc);
return_ACPI_STATUS(status);
}