ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 271 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/nsparse.c b/drivers/acpi/acpica/nsparse.c
new file mode 100644
index 000000000..1e9c70c38
--- /dev/null
+++ b/drivers/acpi/acpica/nsparse.c
@@ -0,0 +1,271 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/******************************************************************************
+ *
+ * Module Name: nsparse - namespace interface to AML parser
+ *
+ * Copyright (C) 2000 - 2026, Intel Corp.
+ *
+ *****************************************************************************/
+
+#include <acpi/acpi.h>
+#include "accommon.h"
+#include "acnamesp.h"
+#include "acparser.h"
+#include "acdispat.h"
+#include "actables.h"
+#include "acinterp.h"
+
+#define _COMPONENT          ACPI_NAMESPACE
+ACPI_MODULE_NAME("nsparse")
+
+/*******************************************************************************
+ *
+ * FUNCTION:    ns_execute_table
+ *
+ * PARAMETERS:  table_desc      - An ACPI table descriptor for table to parse
+ *              start_node      - Where to enter the table into the namespace
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Load ACPI/AML table by executing the entire table as a single
+ *              large control method.
+ *
+ * NOTE: The point of this is to execute any module-level code in-place
+ * as the table is parsed. Some AML code depends on this behavior.
+ *
+ * It is a run-time option at this time, but will eventually become
+ * the default.
+ *
+ * Note: This causes the table to only have a single-pass parse.
+ * However, this is compatible with other ACPI implementations.
+ *
+ ******************************************************************************/
+acpi_status
+acpi_ns_execute_table(u32 table_index, struct acpi_namespace_node *start_node)
+{
+	acpi_status status;
+	struct acpi_table_header *table;
+	acpi_owner_id owner_id;
+	struct acpi_evaluate_info *info = NULL;
+	u32 aml_length;
+	u8 *aml_start;
+	union acpi_operand_object *method_obj = NULL;
+
+	ACPI_FUNCTION_TRACE(ns_execute_table);
+
+	status = acpi_get_table_by_index(table_index, &table);
+	if (ACPI_FAILURE(status)) {
+		return_ACPI_STATUS(status);
+	}
+
+	/* Table must consist of at least a complete header */
+
+	if (table->length < sizeof(struct acpi_table_header)) {
+		return_ACPI_STATUS(AE_BAD_HEADER);
+	}
+
+	aml_start = (u8 *)table + sizeof(struct acpi_table_header);
+	aml_length = table->length - sizeof(struct acpi_table_header);
+
+	status = acpi_tb_get_owner_id(table_index, &owner_id);
+	if (ACPI_FAILURE(status)) {
+		return_ACPI_STATUS(status);
+	}
+
+	/* Create, initialize, and link a new temporary method object */
+
+	method_obj = acpi_ut_create_internal_object(ACPI_TYPE_METHOD);
+	if (!method_obj) {
+		return_ACPI_STATUS(AE_NO_MEMORY);
+	}
+
+	/* Allocate the evaluation information block */
+
+	info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
+	if (!info) {
+		status = AE_NO_MEMORY;
+		goto cleanup;
+	}
+
+	ACPI_DEBUG_PRINT_RAW((ACPI_DB_PARSE,
+			      "%s: Create table pseudo-method for [%4.4s] @%p, method %p\n",
+			      ACPI_GET_FUNCTION_NAME, table->signature, table,
+			      method_obj));
+
+	method_obj->method.aml_start = aml_start;
+	method_obj->method.aml_length = aml_length;
+	method_obj->method.owner_id = owner_id;
+	method_obj->method.info_flags |= ACPI_METHOD_MODULE_LEVEL;
+
+	info->pass_number = ACPI_IMODE_EXECUTE;
+	info->node = start_node;
+	info->obj_desc = method_obj;
+	info->node_flags = info->node->flags;
+	info->full_pathname = acpi_ns_get_normalized_pathname(info->node, TRUE);
+	if (!info->full_pathname) {
+		status = AE_NO_MEMORY;
+		goto cleanup;
+	}
+
+	/* Optional object evaluation log */
+
+	ACPI_DEBUG_PRINT_RAW((ACPI_DB_EVALUATION,
+			      "%-26s:  (Definition Block level)\n",
+			      "Module-level evaluation"));
+
+	status = acpi_ps_execute_table(info);
+
+	/* Optional object evaluation log */
+
+	ACPI_DEBUG_PRINT_RAW((ACPI_DB_EVALUATION,
+			      "%-26s:  (Definition Block level)\n",
+			      "Module-level complete"));
+
+cleanup:
+	if (info) {
+		ACPI_FREE(info->full_pathname);
+		info->full_pathname = NULL;
+	}
+	ACPI_FREE(info);
+	acpi_ut_remove_reference(method_obj);
+	return_ACPI_STATUS(status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    ns_one_complete_parse
+ *
+ * PARAMETERS:  pass_number             - 1 or 2
+ *              table_desc              - The table to be parsed.
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Perform one complete parse of an ACPI/AML table.
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ns_one_complete_parse(u32 pass_number,
+			   u32 table_index,
+			   struct acpi_namespace_node *start_node)
+{
+	union acpi_parse_object *parse_root;
+	acpi_status status;
+	u32 aml_length;
+	u8 *aml_start;
+	struct acpi_walk_state *walk_state;
+	struct acpi_table_header *table;
+	acpi_owner_id owner_id;
+
+	ACPI_FUNCTION_TRACE(ns_one_complete_parse);
+
+	status = acpi_get_table_by_index(table_index, &table);
+	if (ACPI_FAILURE(status)) {
+		return_ACPI_STATUS(status);
+	}
+
+	/* Table must consist of at least a complete header */
+
+	if (table->length < sizeof(struct acpi_table_header)) {
+		return_ACPI_STATUS(AE_BAD_HEADER);
+	}
+
+	aml_start = (u8 *)table + sizeof(struct acpi_table_header);
+	aml_length = table->length - sizeof(struct acpi_table_header);
+
+	status = acpi_tb_get_owner_id(table_index, &owner_id);
+	if (ACPI_FAILURE(status)) {
+		return_ACPI_STATUS(status);
+	}
+
+	/* Create and init a Root Node */
+
+	parse_root = acpi_ps_create_scope_op(aml_start);
+	if (!parse_root) {
+		return_ACPI_STATUS(AE_NO_MEMORY);
+	}
+
+	/* Create and initialize a new walk state */
+
+	walk_state = acpi_ds_create_walk_state(owner_id, NULL, NULL, NULL);
+	if (!walk_state) {
+		acpi_ps_free_op(parse_root);
+		return_ACPI_STATUS(AE_NO_MEMORY);
+	}
+
+	status = acpi_ds_init_aml_walk(walk_state, parse_root, NULL,
+				       aml_start, aml_length, NULL,
+				       (u8)pass_number);
+	if (ACPI_FAILURE(status)) {
+		acpi_ds_delete_walk_state(walk_state);
+		goto cleanup;
+	}
+
+	/* Found OSDT table, enable the namespace override feature */
+
+	if (ACPI_COMPARE_NAMESEG(table->signature, ACPI_SIG_OSDT) &&
+	    pass_number == ACPI_IMODE_LOAD_PASS1) {
+		walk_state->namespace_override = TRUE;
+	}
+
+	/* start_node is the default location to load the table */
+
+	if (start_node && start_node != acpi_gbl_root_node) {
+		status =
+		    acpi_ds_scope_stack_push(start_node, ACPI_TYPE_METHOD,
+					     walk_state);
+		if (ACPI_FAILURE(status)) {
+			acpi_ds_delete_walk_state(walk_state);
+			goto cleanup;
+		}
+	}
+
+	/* Parse the AML */
+
+	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
+			  "*PARSE* pass %u parse\n", pass_number));
+	acpi_ex_enter_interpreter();
+	status = acpi_ps_parse_aml(walk_state);
+	acpi_ex_exit_interpreter();
+
+cleanup:
+	acpi_ps_delete_parse_tree(parse_root);
+	return_ACPI_STATUS(status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ns_parse_table
+ *
+ * PARAMETERS:  table_desc      - An ACPI table descriptor for table to parse
+ *              start_node      - Where to enter the table into the namespace
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Parse AML within an ACPI table and return a tree of ops
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ns_parse_table(u32 table_index, struct acpi_namespace_node *start_node)
+{
+	acpi_status status;
+
+	ACPI_FUNCTION_TRACE(ns_parse_table);
+
+	/*
+	 * Executes the AML table as one large control method.
+	 * The point of this is to execute any module-level code in-place
+	 * as the table is parsed. Some AML code depends on this behavior.
+	 *
+	 * Note: This causes the table to only have a single-pass parse.
+	 * However, this is compatible with other ACPI implementations.
+	 */
+	ACPI_DEBUG_PRINT_RAW((ACPI_DB_PARSE,
+			      "%s: **** Start table execution pass\n",
+			      ACPI_GET_FUNCTION_NAME));
+
+	status = acpi_ns_execute_table(table_index, start_node);
+
+	return_ACPI_STATUS(status);
+}