[PATCH 38/42] ACPICA: Events: Enhance acpi_ev_execute_reg_method() to ensure no _REG evaluations can happen during OS early boot stages

From: Lv Zheng
Date: Tue Dec 29 2015 - 01:03:31 EST


ACPICA commit 31178590dde82368fdb0f6b0e466b6c0add96c57

We can ensure no early _REG evaluations by ensuring the following rules in
acpi_ev_execute_reg_method():
1. If an address space handler is installed during early stage,
_REG(CONNECT) evaluations are blocked. This is achieved using
acpi_gbl_reg_methods_enabled which is renamed from
acpi_gbl_reg_methods_executed.
2. If _REG(CONNECT) has never been evalauted for the region object,
_REG(DISCONNECT) evaluations are blocked. This is achieved by a new
region object flag: AOPOBJ_REG_CONNECTED.
Note that, after applying this patch, we can ensure _REG(DISCONNECT) is
always paired to _REG(CONNECT). Lv Zheng

Link: https://github.com/acpica/acpica/commit/31178590
Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx>
---
drivers/acpi/acpica/acglobal.h | 2 +-
drivers/acpi/acpica/acobject.h | 7 ++++---
drivers/acpi/acpica/evregion.c | 25 ++++++++++++++++++++++---
drivers/acpi/acpica/evxfregn.c | 33 ---------------------------------
drivers/acpi/acpica/excreate.c | 3 ++-
drivers/acpi/acpica/utinit.c | 1 -
drivers/acpi/acpica/utxfinit.c | 1 +
7 files changed, 30 insertions(+), 42 deletions(-)

diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h
index ef0abf4..73462ca 100644
--- a/drivers/acpi/acpica/acglobal.h
+++ b/drivers/acpi/acpica/acglobal.h
@@ -165,7 +165,7 @@ ACPI_GLOBAL(u8, acpi_gbl_next_owner_id_offset);

/* Initialization sequencing */

-ACPI_GLOBAL(u8, acpi_gbl_reg_methods_executed);
+ACPI_INIT_GLOBAL(u8, acpi_gbl_reg_methods_enabled, FALSE);

/* Misc */

diff --git a/drivers/acpi/acpica/acobject.h b/drivers/acpi/acpica/acobject.h
index 0bd02c4..2b154cf 100644
--- a/drivers/acpi/acpica/acobject.h
+++ b/drivers/acpi/acpica/acobject.h
@@ -93,9 +93,10 @@
#define AOPOBJ_AML_CONSTANT 0x01 /* Integer is an AML constant */
#define AOPOBJ_STATIC_POINTER 0x02 /* Data is part of an ACPI table, don't delete */
#define AOPOBJ_DATA_VALID 0x04 /* Object is initialized and data is valid */
-#define AOPOBJ_OBJECT_INITIALIZED 0x08 /* Region is initialized, _REG was run */
-#define AOPOBJ_SETUP_COMPLETE 0x10 /* Region setup is complete */
-#define AOPOBJ_INVALID 0x20 /* Host OS won't allow a Region address */
+#define AOPOBJ_OBJECT_INITIALIZED 0x08 /* Region is initialized */
+#define AOPOBJ_REG_CONNECTED 0x10 /* _REG was run */
+#define AOPOBJ_SETUP_COMPLETE 0x20 /* Region setup is complete */
+#define AOPOBJ_INVALID 0x40 /* Host OS won't allow a Region address */

/******************************************************************************
*
diff --git a/drivers/acpi/acpica/evregion.c b/drivers/acpi/acpica/evregion.c
index 432b810..cf6e878 100644
--- a/drivers/acpi/acpica/evregion.c
+++ b/drivers/acpi/acpica/evregion.c
@@ -104,8 +104,6 @@ acpi_status acpi_ev_initialize_op_regions(void)
}
}

- acpi_gbl_reg_methods_executed = TRUE;
-
(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
return_ACPI_STATUS(status);
}
@@ -601,7 +599,18 @@ acpi_ev_execute_reg_method(union acpi_operand_object *region_obj, u32 function)
return_ACPI_STATUS(AE_NOT_EXIST);
}

- if (region_obj2->extra.method_REG == NULL) {
+ if (region_obj2->extra.method_REG == NULL ||
+ region_obj->region.handler == NULL ||
+ !acpi_gbl_reg_methods_enabled) {
+ return_ACPI_STATUS(AE_OK);
+ }
+
+ /* _REG(DISCONNECT) should be paired with _REG(CONNECT) */
+
+ if ((function == ACPI_REG_CONNECT &&
+ region_obj->common.flags & AOPOBJ_REG_CONNECTED) ||
+ (function == ACPI_REG_DISCONNECT &&
+ !(region_obj->common.flags & AOPOBJ_REG_CONNECTED))) {
return_ACPI_STATUS(AE_OK);
}

@@ -650,6 +659,16 @@ acpi_ev_execute_reg_method(union acpi_operand_object *region_obj, u32 function)
status = acpi_ns_evaluate(info);
acpi_ut_remove_reference(args[1]);

+ if (ACPI_FAILURE(status)) {
+ goto cleanup2;
+ }
+
+ if (function == ACPI_REG_CONNECT) {
+ region_obj->common.flags |= AOPOBJ_REG_CONNECTED;
+ } else {
+ region_obj->common.flags &= ~AOPOBJ_REG_CONNECTED;
+ }
+
cleanup2:
acpi_ut_remove_reference(args[0]);

diff --git a/drivers/acpi/acpica/evxfregn.c b/drivers/acpi/acpica/evxfregn.c
index 3c90508..29f9f39 100644
--- a/drivers/acpi/acpica/evxfregn.c
+++ b/drivers/acpi/acpica/evxfregn.c
@@ -112,39 +112,6 @@ acpi_install_address_space_handler(acpi_handle device,
goto unlock_and_exit;
}

- /*
- * For the default space_IDs, (the IDs for which there are default region handlers
- * installed) Only execute the _REG methods if the global initialization _REG
- * methods have already been run (via acpi_initialize_objects). In other words,
- * we will defer the execution of the _REG methods for these space_IDs until
- * execution of acpi_initialize_objects. This is done because we need the handlers
- * for the default spaces (mem/io/pci/table) to be installed before we can run
- * any control methods (or _REG methods). There is known BIOS code that depends
- * on this.
- *
- * For all other space_IDs, we can safely execute the _REG methods immediately.
- * This means that for IDs like embedded_controller, this function should be called
- * only after acpi_enable_subsystem has been called.
- */
- switch (space_id) {
- case ACPI_ADR_SPACE_SYSTEM_MEMORY:
- case ACPI_ADR_SPACE_SYSTEM_IO:
- case ACPI_ADR_SPACE_PCI_CONFIG:
- case ACPI_ADR_SPACE_DATA_TABLE:
-
- if (!acpi_gbl_reg_methods_executed) {
-
- /* We will defer execution of the _REG methods for this space */
-
- goto unlock_and_exit;
- }
- break;
-
- default:
-
- break;
- }
-
/* Run all _REG methods for this address space */

status = acpi_ev_execute_reg_methods(node, space_id);
diff --git a/drivers/acpi/acpica/excreate.c b/drivers/acpi/acpica/excreate.c
index 6a1396e..46be5a2 100644
--- a/drivers/acpi/acpica/excreate.c
+++ b/drivers/acpi/acpica/excreate.c
@@ -345,7 +345,8 @@ acpi_ex_create_region(u8 * aml_start,
obj_desc->region.node = node;
obj_desc->region.handler = NULL;
obj_desc->common.flags &=
- ~(AOPOBJ_SETUP_COMPLETE | AOPOBJ_OBJECT_INITIALIZED);
+ ~(AOPOBJ_SETUP_COMPLETE | AOPOBJ_REG_CONNECTED |
+ AOPOBJ_OBJECT_INITIALIZED);

/* Install the new region object in the parent Node */

diff --git a/drivers/acpi/acpica/utinit.c b/drivers/acpi/acpica/utinit.c
index ccd0745..fd82a12 100644
--- a/drivers/acpi/acpica/utinit.c
+++ b/drivers/acpi/acpica/utinit.c
@@ -206,7 +206,6 @@ acpi_status acpi_ut_init_globals(void)
acpi_gbl_next_owner_id_offset = 0;
acpi_gbl_debugger_configuration = DEBUGGER_THREADING;
acpi_gbl_osi_mutex = NULL;
- acpi_gbl_reg_methods_executed = FALSE;
acpi_gbl_max_loop_iterations = 0xFFFF;

/* Hardware oriented */
diff --git a/drivers/acpi/acpica/utxfinit.c b/drivers/acpi/acpica/utxfinit.c
index 7d8eb60..1c7ed49 100644
--- a/drivers/acpi/acpica/utxfinit.c
+++ b/drivers/acpi/acpica/utxfinit.c
@@ -267,6 +267,7 @@ acpi_status __init acpi_initialize_objects(u32 flags)
* initialized, even if they contain executable AML (see the call to
* acpi_ns_initialize_objects below).
*/
+ acpi_gbl_reg_methods_enabled = TRUE;
if (!(flags & ACPI_NO_ADDRESS_SPACE_INIT)) {
ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
"[Init] Executing _REG OpRegion methods\n"));
--
1.7.10

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