[PATCH v5 1/5] ACPICA: Tables: Fix "UNLOAD" code path lock issues

[Lv Zheng]

ACPICA commit 39227380f5b99c51b897a3ffedd88508aa26789b

The previous lock fixes didn't cover "Unload" opcode and table unload APIs,
this patch fixes lock issues in the "Unload" code path. BZ 1325, Lv Zheng.

Link: https://github.com/acpica/acpica/commit/39227380
Link: https://bugs.acpica.org/show_bug.cgi?id=1325
Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx>
---
 drivers/acpi/acpica/exconfig.c |   23 +++++++++++++++++++----
 drivers/acpi/acpica/tbdata.c   |    7 +------
 drivers/acpi/acpica/tbxfload.c |    9 ++++++---
 3 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/drivers/acpi/acpica/exconfig.c b/drivers/acpi/acpica/exconfig.c
index 421836a..718428b 100644
--- a/drivers/acpi/acpica/exconfig.c
+++ b/drivers/acpi/acpica/exconfig.c
@@ -532,10 +532,17 @@ acpi_status acpi_ex_unload_table(union acpi_operand_object *ddb_handle)
 
 	table_index = table_desc->reference.value;
 
+	/*
+	 * Release the interpreter lock so that the table lock won't have
+	 * strict order requirement against it.
+	 */
+	acpi_ex_exit_interpreter();
+
 	/* Ensure the table is still loaded */
 
 	if (!acpi_tb_is_table_loaded(table_index)) {
-		return_ACPI_STATUS(AE_NOT_EXIST);
+		status = AE_NOT_EXIST;
+		goto lock_and_exit;
 	}
 
 	/* Invoke table handler if present */
@@ -553,16 +560,24 @@ acpi_status acpi_ex_unload_table(union acpi_operand_object *ddb_handle)
 
 	status = acpi_tb_delete_namespace_by_owner(table_index);
 	if (ACPI_FAILURE(status)) {
-		return_ACPI_STATUS(status);
+		goto lock_and_exit;
 	}
 
 	(void)acpi_tb_release_owner_id(table_index);
 	acpi_tb_set_table_loaded_flag(table_index, FALSE);
 
+lock_and_exit:
+
+	/* Re-acquire the interpreter lock */
+
+	acpi_ex_enter_interpreter();
+
 	/*
 	 * Invalidate the handle. We do this because the handle may be stored
 	 * in a named object and may not be actually deleted until much later.
 	 */
-	ddb_handle->common.flags &= ~AOPOBJ_DATA_VALID;
-	return_ACPI_STATUS(AE_OK);
+	if (ACPI_SUCCESS(status)) {
+		ddb_handle->common.flags &= ~AOPOBJ_DATA_VALID;
+	}
+	return_ACPI_STATUS(status);
 }
diff --git a/drivers/acpi/acpica/tbdata.c b/drivers/acpi/acpica/tbdata.c
index 7e93fd6..d9ca8c2 100644
--- a/drivers/acpi/acpica/tbdata.c
+++ b/drivers/acpi/acpica/tbdata.c
@@ -614,17 +614,12 @@ acpi_status acpi_tb_delete_namespace_by_owner(u32 table_index)
 	 * lock may block, and also since the execution of a namespace walk
 	 * must be allowed to use the interpreter.
 	 */
-	(void)acpi_ut_release_mutex(ACPI_MTX_INTERPRETER);
 	status = acpi_ut_acquire_write_lock(&acpi_gbl_namespace_rw_lock);
-
-	acpi_ns_delete_namespace_by_owner(owner_id);
 	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
 	}
-
+	acpi_ns_delete_namespace_by_owner(owner_id);
 	acpi_ut_release_write_lock(&acpi_gbl_namespace_rw_lock);
-
-	status = acpi_ut_acquire_mutex(ACPI_MTX_INTERPRETER);
 	return_ACPI_STATUS(status);
 }
 
diff --git a/drivers/acpi/acpica/tbxfload.c b/drivers/acpi/acpica/tbxfload.c
index 870ad64..5569f63 100644
--- a/drivers/acpi/acpica/tbxfload.c
+++ b/drivers/acpi/acpica/tbxfload.c
@@ -378,9 +378,9 @@ acpi_status acpi_unload_parent_table(acpi_handle object)
 		return_ACPI_STATUS(AE_TYPE);
 	}
 
-	/* Must acquire the interpreter lock during this operation */
+	/* Must acquire the table lock during this operation */
 
-	status = acpi_ut_acquire_mutex(ACPI_MTX_INTERPRETER);
+	status = acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
 	}
@@ -407,8 +407,10 @@ acpi_status acpi_unload_parent_table(acpi_handle object)
 
 		/* Ensure the table is actually loaded */
 
+		(void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 		if (!acpi_tb_is_table_loaded(i)) {
 			status = AE_NOT_EXIST;
+			(void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 			break;
 		}
 
@@ -434,10 +436,11 @@ acpi_status acpi_unload_parent_table(acpi_handle object)
 
 		status = acpi_tb_release_owner_id(i);
 		acpi_tb_set_table_loaded_flag(i, FALSE);
+		(void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 		break;
 	}
 
-	(void)acpi_ut_release_mutex(ACPI_MTX_INTERPRETER);
+	(void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 	return_ACPI_STATUS(status);
 }
 
-- 
1.7.10