Skip to content

Commit

Permalink
ACPICA: Tables: Fix table checksums verification before installation.
Browse files Browse the repository at this point in the history 
The original table handling code does not always verify checksums before
installing a table, this is because code to achieve this must be
implemented here and there in the redundant code blocks.

There are two stages during table initialization:
1. "INSTALLED" after acpi_tb_install_table() and acpi_tb_override_table(),
   struct acpi_table_desc.Pointer is ensured to be NULL.  This can be safely used
   during OSPM's early boot stage.
2. "VALIDATED" after acpi_tb_validate_table(), struct acpi_table_desc.Pointer is
   ensured to be not NULL.  This must not be used during OSPM's early boot
   stage.

This patch changes acpi_tb_add_table() into an early boot safe API to reduce
code redundancies by changing the table state that is returned by this
function from "VALIDATED" to "INSTALLED".  Then the table verification
code can be done in a single place.  Originally, the acpi_tb_add_table() can
only be used by dynamic table loadings that are executed after early boot
stage, it cannot be used by static table loadings that are executed in
early boot stage as:
1.  The address of the table is a virtual address either maintained by
    OSPMs who call acpi_load_table() or by ACPICA whenever "Load" or
    "LoadTable" opcodes are executed, while during early boot stage,
    physical address of the table should be used for table loading.
2.  The API will ensure the state of the loaded table to be "VALIDATED"
    while during early boot stage, tables maintained by root table list
    should be kept as "INSTALLED".

To achieve this:
1. Rename acpi_tb_install_table() to acpi_tb_install_fixed_table() as it only
   applies to DSDT/FACS installation.  Rename acpi_tb_add_table() to
   acpi_tb_install_non_fixed_table() as it will be applied to the installation
   of the rest kinds of tables.
2. Introduce acpi_tb_install_table(), acpi_tb_install_and_override_table to collect
   redudant code where their invocations actually have slight differences.
   1. acpi_tb_install_table() is used to fill an struct acpi_table_desc where the
      table length is known to the caller.
   2. acpi_tb_install_and_override_table() is used to perform necessary
      overriding before installation.
3. Change a parameter of acpi_tb_install_non_fixed_table() from struct acpi_table_desc
   to acpi_physical_address to allow it to be invoked by static table
   loadings.  Also cleanup acpi_ex_load_op() and acpi_load_table() to accomodate
   to the parameter change.
4. Invoke acpi_tb_install_non_fixed_table() for all table loadings other than
   DSDT/FACS in acpi_tb_parse_root_table() to improve code maintainability
   (logics are collected in the single function).  Also delete useless code
   from acpi_tb_parse_root_table().
5. Remove all acpi_tb_validate_table() from acpi_tb_install_non_fixed_table() and
   acpi_tb_install_fixed_table() so that the table descriptor is kept in the
   state of "INSTALLED" but not "VALIDATED" after returning from these
   functions.
6. Introduce temporary struct acpi_table_desc (new_table_desc/old_table_desc) into
   the functions to indicate a table descriptor that is not maintained by
   acpi_gbl_root_table_list. Introduce acpi_tb_acquire_temporal_table() and
   acpi_tb_release_temporal_table() to handle the use cases of such temporal
   tables.  They are only used for verified installation.
7. Introduce acpi_tb_verify_table() to validate table and verify table
   checksum, also remove table checksum verification from
   acpi_tb_validate_table(). Invoke acpi_tb_validate_table() in the functions
   that will convert a table into "LOADED" state or invoke it from
   acpi_get_table_XXX() APIs. Invoke acpi_tb_verify_table() on temporary
   struct acpi_table_desc(s) that are going to be "INSTALLED".
8. Change acpi_tb_override_table() logic so that a temporary struct acpi_table_desc
   will be overridden before installtion, this makes code simpler.

After applying the patch, tables are always installed after being
overridden and the table checksums are always verified before installation.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
[rjw: Subject]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  • Loading branch information
Lv Zheng authored and Rafael J. Wysocki committed Apr 20, 2014
1 parent eb0c65b commit 86dfc6f
Show file tree
Hide file tree
Showing 6 changed files with 607 additions and 409 deletions.
24 changes: 17 additions & 7 deletions drivers/acpi/acpica/actables.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -76,10 +76,10 @@ acpi_status acpi_tb_validate_table(struct acpi_table_desc *table_desc);

void acpi_tb_invalidate_table(struct acpi_table_desc *table_desc);

struct acpi_table_header *acpi_tb_override_table(struct acpi_table_header
*table_header,
struct acpi_table_desc
*table_desc);
acpi_status
acpi_tb_verify_table(struct acpi_table_desc *table_desc, char *signature);

void acpi_tb_override_table(struct acpi_table_desc *old_table_desc);

acpi_status
acpi_tb_acquire_table(struct acpi_table_desc *table_desc,
Expand All @@ -91,7 +91,8 @@ acpi_tb_release_table(struct acpi_table_header *table,
u32 table_length, u8 table_flags);

acpi_status
acpi_tb_add_table(struct acpi_table_desc *table_desc, u32 *table_index);
acpi_tb_install_non_fixed_table(acpi_physical_address address,
u8 flags, u8 reload, u32 *table_index);

acpi_status
acpi_tb_store_table(acpi_physical_address address,
Expand Down Expand Up @@ -135,8 +136,17 @@ void acpi_tb_check_dsdt_header(void);
struct acpi_table_header *acpi_tb_copy_dsdt(u32 table_index);

void
acpi_tb_install_table(acpi_physical_address address,
char *signature, u32 table_index);
acpi_tb_install_table(struct acpi_table_desc *table_desc,
acpi_physical_address address,
u8 flags, struct acpi_table_header *table);

void
acpi_tb_install_and_override_table(u32 table_index,
struct acpi_table_desc *new_table_desc);

acpi_status
acpi_tb_install_fixed_table(acpi_physical_address address,
char *signature, u32 table_index);

acpi_status acpi_tb_parse_root_table(acpi_physical_address rsdp_address);

Expand Down
75 changes: 34 additions & 41 deletions drivers/acpi/acpica/exconfig.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -343,16 +343,14 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,
struct acpi_walk_state *walk_state)
{
union acpi_operand_object *ddb_handle;
struct acpi_table_header *table_header;
struct acpi_table_header *table;
struct acpi_table_desc table_desc;
u32 table_index;
acpi_status status;
u32 length;

ACPI_FUNCTION_TRACE(ex_load_op);

ACPI_MEMSET(&table_desc, 0, sizeof(struct acpi_table_desc));

/* Source Object can be either an op_region or a Buffer/Field */

switch (obj_desc->common.type) {
Expand Down Expand Up @@ -380,17 +378,17 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,

/* Get the table header first so we can get the table length */

table = ACPI_ALLOCATE(sizeof(struct acpi_table_header));
if (!table) {
table_header = ACPI_ALLOCATE(sizeof(struct acpi_table_header));
if (!table_header) {
return_ACPI_STATUS(AE_NO_MEMORY);
}

status =
acpi_ex_region_read(obj_desc,
sizeof(struct acpi_table_header),
ACPI_CAST_PTR(u8, table));
length = table->length;
ACPI_FREE(table);
ACPI_CAST_PTR(u8, table_header));
length = table_header->length;
ACPI_FREE(table_header);

if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
Expand Down Expand Up @@ -420,22 +418,19 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,

/* Allocate a buffer for the table */

table_desc.pointer = ACPI_ALLOCATE(length);
if (!table_desc.pointer) {
table = ACPI_ALLOCATE(length);
if (!table) {
return_ACPI_STATUS(AE_NO_MEMORY);
}

/* Read the entire table */

status = acpi_ex_region_read(obj_desc, length,
ACPI_CAST_PTR(u8,
table_desc.pointer));
ACPI_CAST_PTR(u8, table));
if (ACPI_FAILURE(status)) {
ACPI_FREE(table_desc.pointer);
ACPI_FREE(table);
return_ACPI_STATUS(status);
}

table_desc.address = ACPI_PTR_TO_PHYSADDR(table_desc.pointer);
break;

case ACPI_TYPE_BUFFER: /* Buffer or resolved region_field */
Expand All @@ -452,10 +447,10 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,

/* Get the actual table length from the table header */

table =
table_header =
ACPI_CAST_PTR(struct acpi_table_header,
obj_desc->buffer.pointer);
length = table->length;
length = table_header->length;

/* Table cannot extend beyond the buffer */

Expand All @@ -470,41 +465,43 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,
* Copy the table from the buffer because the buffer could be modified
* or even deleted in the future
*/
table_desc.pointer = ACPI_ALLOCATE(length);
if (!table_desc.pointer) {
table = ACPI_ALLOCATE(length);
if (!table) {
return_ACPI_STATUS(AE_NO_MEMORY);
}

ACPI_MEMCPY(table_desc.pointer, table, length);
table_desc.address = ACPI_PTR_TO_PHYSADDR(table_desc.pointer);
ACPI_MEMCPY(table, table_header, length);
break;

default:

return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
}

/* Validate table checksum (will not get validated in tb_add_table) */

status = acpi_tb_verify_checksum(table_desc.pointer, length);
if (ACPI_FAILURE(status)) {
ACPI_FREE(table_desc.pointer);
return_ACPI_STATUS(status);
}

/* Complete the table descriptor */

table_desc.length = length;
table_desc.flags = ACPI_TABLE_ORIGIN_ALLOCATED;

/* Install the new table into the local data structures */

status = acpi_tb_add_table(&table_desc, &table_index);
ACPI_INFO((AE_INFO, "Dynamic OEM Table Load:"));
(void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
status = acpi_tb_install_non_fixed_table(ACPI_PTR_TO_PHYSADDR(table),
ACPI_TABLE_ORIGIN_ALLOCATED,
TRUE, &table_index);
(void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
if (ACPI_FAILURE(status)) {

/* Delete allocated table buffer */

ACPI_FREE(table_desc.pointer);
ACPI_FREE(table);
return_ACPI_STATUS(status);
}

/*
* Note: Now table is "INSTALLED", it must be validated before
* loading.
*/
status =
acpi_tb_validate_table(&acpi_gbl_root_table_list.
tables[table_index]);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}

Expand Down Expand Up @@ -536,18 +533,14 @@ acpi_ex_load_op(union acpi_operand_object *obj_desc,
return_ACPI_STATUS(status);
}

ACPI_INFO((AE_INFO, "Dynamic OEM Table Load:"));
acpi_tb_print_table_header(0, table_desc.pointer);

/* Remove the reference by added by acpi_ex_store above */

acpi_ut_remove_reference(ddb_handle);

/* Invoke table handler if present */

if (acpi_gbl_table_handler) {
(void)acpi_gbl_table_handler(ACPI_TABLE_EVENT_LOAD,
table_desc.pointer,
(void)acpi_gbl_table_handler(ACPI_TABLE_EVENT_LOAD, table,
acpi_gbl_table_handler_context);
}

Expand Down
10 changes: 5 additions & 5 deletions drivers/acpi/acpica/tbfadt.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -332,15 +332,15 @@ void acpi_tb_parse_fadt(u32 table_index)

/* Obtain the DSDT and FACS tables via their addresses within the FADT */

acpi_tb_install_table((acpi_physical_address) acpi_gbl_FADT.Xdsdt,
ACPI_SIG_DSDT, ACPI_TABLE_INDEX_DSDT);
acpi_tb_install_fixed_table((acpi_physical_address) acpi_gbl_FADT.Xdsdt,
ACPI_SIG_DSDT, ACPI_TABLE_INDEX_DSDT);

/* If Hardware Reduced flag is set, there is no FACS */

if (!acpi_gbl_reduced_hardware) {
acpi_tb_install_table((acpi_physical_address) acpi_gbl_FADT.
Xfacs, ACPI_SIG_FACS,
ACPI_TABLE_INDEX_FACS);
acpi_tb_install_fixed_table((acpi_physical_address)
acpi_gbl_FADT.Xfacs, ACPI_SIG_FACS,
ACPI_TABLE_INDEX_FACS);
}
}

Expand Down
Loading

0 comments on commit 86dfc6f

Please sign in to comment.