Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 1101 insertions, 0 deletions

diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
new file mode 100644
index 000000000..d499b7257
--- /dev/null
+++ b/drivers/acpi/utils.c
@@ -0,0 +1,1101 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  acpi_utils.c - ACPI Utility Functions ($Revision: 10 $)
+ *
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ */
+
+#define pr_fmt(fmt) "ACPI: utils: " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/hardirq.h>
+#include <linux/acpi.h>
+#include <linux/dynamic_debug.h>
+
+#include "internal.h"
+#include "sleep.h"
+
+/* --------------------------------------------------------------------------
+                            Object Evaluation Helpers
+   -------------------------------------------------------------------------- */
+static void acpi_util_eval_error(acpi_handle h, acpi_string p, acpi_status s)
+{
+	acpi_handle_debug(h, "Evaluate [%s]: %s\n", p, acpi_format_exception(s));
+}
+
+acpi_status
+acpi_extract_package(union acpi_object *package,
+		     struct acpi_buffer *format, struct acpi_buffer *buffer)
+{
+	u32 size_required = 0;
+	u32 tail_offset = 0;
+	char *format_string = NULL;
+	u32 format_count = 0;
+	u32 i = 0;
+	u8 *head = NULL;
+	u8 *tail = NULL;
+
+
+	if (!package || (package->type != ACPI_TYPE_PACKAGE)
+	    || (package->package.count < 1)) {
+		pr_debug("Invalid package argument\n");
+		return AE_BAD_PARAMETER;
+	}
+
+	if (!format || !format->pointer || (format->length < 1)) {
+		pr_debug("Invalid format argument\n");
+		return AE_BAD_PARAMETER;
+	}
+
+	if (!buffer) {
+		pr_debug("Invalid buffer argument\n");
+		return AE_BAD_PARAMETER;
+	}
+
+	format_count = (format->length / sizeof(char)) - 1;
+	if (format_count > package->package.count) {
+		pr_debug("Format specifies more objects [%d] than present [%d]\n",
+			 format_count, package->package.count);
+		return AE_BAD_DATA;
+	}
+
+	format_string = format->pointer;
+
+	/*
+	 * Calculate size_required.
+	 */
+	for (i = 0; i < format_count; i++) {
+
+		union acpi_object *element = &(package->package.elements[i]);
+
+		switch (element->type) {
+
+		case ACPI_TYPE_INTEGER:
+			switch (format_string[i]) {
+			case 'N':
+				size_required += sizeof(u64);
+				tail_offset += sizeof(u64);
+				break;
+			case 'S':
+				size_required +=
+				    sizeof(char *) + sizeof(u64) +
+				    sizeof(char);
+				tail_offset += sizeof(char *);
+				break;
+			default:
+				pr_debug("Invalid package element [%d]: got number, expected [%c]\n",
+					 i, format_string[i]);
+				return AE_BAD_DATA;
+			}
+			break;
+
+		case ACPI_TYPE_STRING:
+		case ACPI_TYPE_BUFFER:
+			switch (format_string[i]) {
+			case 'S':
+				size_required +=
+				    sizeof(char *) +
+				    (element->string.length * sizeof(char)) +
+				    sizeof(char);
+				tail_offset += sizeof(char *);
+				break;
+			case 'B':
+				size_required +=
+				    sizeof(u8 *) + element->buffer.length;
+				tail_offset += sizeof(u8 *);
+				break;
+			default:
+				pr_debug("Invalid package element [%d] got string/buffer, expected [%c]\n",
+					 i, format_string[i]);
+				return AE_BAD_DATA;
+			}
+			break;
+		case ACPI_TYPE_LOCAL_REFERENCE:
+			switch (format_string[i]) {
+			case 'R':
+				size_required += sizeof(void *);
+				tail_offset += sizeof(void *);
+				break;
+			default:
+				pr_debug("Invalid package element [%d] got reference, expected [%c]\n",
+					 i, format_string[i]);
+				return AE_BAD_DATA;
+			}
+			break;
+
+		case ACPI_TYPE_PACKAGE:
+		default:
+			pr_debug("Unsupported element at index=%d\n", i);
+			/* TBD: handle nested packages... */
+			return AE_SUPPORT;
+		}
+	}
+
+	/*
+	 * Validate output buffer.
+	 */
+	if (buffer->length == ACPI_ALLOCATE_BUFFER) {
+		buffer->pointer = ACPI_ALLOCATE_ZEROED(size_required);
+		if (!buffer->pointer)
+			return AE_NO_MEMORY;
+		buffer->length = size_required;
+	} else {
+		if (buffer->length < size_required) {
+			buffer->length = size_required;
+			return AE_BUFFER_OVERFLOW;
+		} else if (buffer->length != size_required ||
+			   !buffer->pointer) {
+			return AE_BAD_PARAMETER;
+		}
+	}
+
+	head = buffer->pointer;
+	tail = buffer->pointer + tail_offset;
+
+	/*
+	 * Extract package data.
+	 */
+	for (i = 0; i < format_count; i++) {
+
+		u8 **pointer = NULL;
+		union acpi_object *element = &(package->package.elements[i]);
+
+		switch (element->type) {
+
+		case ACPI_TYPE_INTEGER:
+			switch (format_string[i]) {
+			case 'N':
+				*((u64 *) head) =
+				    element->integer.value;
+				head += sizeof(u64);
+				break;
+			case 'S':
+				pointer = (u8 **) head;
+				*pointer = tail;
+				*((u64 *) tail) =
+				    element->integer.value;
+				head += sizeof(u64 *);
+				tail += sizeof(u64);
+				/* NULL terminate string */
+				*tail = (char)0;
+				tail += sizeof(char);
+				break;
+			default:
+				/* Should never get here */
+				break;
+			}
+			break;
+
+		case ACPI_TYPE_STRING:
+		case ACPI_TYPE_BUFFER:
+			switch (format_string[i]) {
+			case 'S':
+				pointer = (u8 **) head;
+				*pointer = tail;
+				memcpy(tail, element->string.pointer,
+				       element->string.length);
+				head += sizeof(char *);
+				tail += element->string.length * sizeof(char);
+				/* NULL terminate string */
+				*tail = (char)0;
+				tail += sizeof(char);
+				break;
+			case 'B':
+				pointer = (u8 **) head;
+				*pointer = tail;
+				memcpy(tail, element->buffer.pointer,
+				       element->buffer.length);
+				head += sizeof(u8 *);
+				tail += element->buffer.length;
+				break;
+			default:
+				/* Should never get here */
+				break;
+			}
+			break;
+		case ACPI_TYPE_LOCAL_REFERENCE:
+			switch (format_string[i]) {
+			case 'R':
+				*(void **)head =
+				    (void *)element->reference.handle;
+				head += sizeof(void *);
+				break;
+			default:
+				/* Should never get here */
+				break;
+			}
+			break;
+		case ACPI_TYPE_PACKAGE:
+			/* TBD: handle nested packages... */
+		default:
+			/* Should never get here */
+			break;
+		}
+	}
+
+	return AE_OK;
+}
+
+EXPORT_SYMBOL(acpi_extract_package);
+
+acpi_status
+acpi_evaluate_integer(acpi_handle handle,
+		      acpi_string pathname,
+		      struct acpi_object_list *arguments, unsigned long long *data)
+{
+	acpi_status status = AE_OK;
+	union acpi_object element;
+	struct acpi_buffer buffer = { 0, NULL };
+
+	if (!data)
+		return AE_BAD_PARAMETER;
+
+	buffer.length = sizeof(union acpi_object);
+	buffer.pointer = &element;
+	status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
+	if (ACPI_FAILURE(status)) {
+		acpi_util_eval_error(handle, pathname, status);
+		return status;
+	}
+
+	if (element.type != ACPI_TYPE_INTEGER) {
+		acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
+		return AE_BAD_DATA;
+	}
+
+	*data = element.integer.value;
+
+	acpi_handle_debug(handle, "Return value [%llu]\n", *data);
+
+	return AE_OK;
+}
+
+EXPORT_SYMBOL(acpi_evaluate_integer);
+
+int acpi_get_local_u64_address(acpi_handle handle, u64 *addr)
+{
+	acpi_status status;
+
+	status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, addr);
+	if (ACPI_FAILURE(status))
+		return -ENODATA;
+	return 0;
+}
+EXPORT_SYMBOL(acpi_get_local_u64_address);
+
+int acpi_get_local_address(acpi_handle handle, u32 *addr)
+{
+	u64 adr;
+	int ret;
+
+	ret = acpi_get_local_u64_address(handle, &adr);
+	if (ret < 0)
+		return ret;
+	*addr = (u32)adr;
+	return 0;
+}
+EXPORT_SYMBOL(acpi_get_local_address);
+
+#define ACPI_MAX_SUB_BUF_SIZE	9
+
+const char *acpi_get_subsystem_id(acpi_handle handle)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *obj;
+	acpi_status status;
+	const char *sub;
+	size_t len;
+
+	status = acpi_evaluate_object(handle, METHOD_NAME__SUB, NULL, &buffer);
+	if (ACPI_FAILURE(status)) {
+		acpi_handle_debug(handle, "Reading ACPI _SUB failed: %#x\n", status);
+		return ERR_PTR(-ENODATA);
+	}
+
+	obj = buffer.pointer;
+	if (obj->type == ACPI_TYPE_STRING) {
+		len = strlen(obj->string.pointer);
+		if (len < ACPI_MAX_SUB_BUF_SIZE && len > 0) {
+			sub = kstrdup(obj->string.pointer, GFP_KERNEL);
+			if (!sub)
+				sub = ERR_PTR(-ENOMEM);
+		} else {
+			acpi_handle_err(handle, "ACPI _SUB Length %zu is Invalid\n", len);
+			sub = ERR_PTR(-ENODATA);
+		}
+	} else {
+		acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n");
+		sub = ERR_PTR(-ENODATA);
+	}
+
+	acpi_os_free(buffer.pointer);
+
+	return sub;
+}
+EXPORT_SYMBOL_GPL(acpi_get_subsystem_id);
+
+bool acpi_evaluate_reference(acpi_handle handle, acpi_string pathname,
+			     struct acpi_object_list *arguments,
+			     struct acpi_handle_list *list)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *package;
+	acpi_status status;
+	bool ret = false;
+	u32 i;
+
+	if (!list)
+		return false;
+
+	/* Evaluate object. */
+
+	status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
+	if (ACPI_FAILURE(status))
+		goto end;
+
+	package = buffer.pointer;
+
+	if (buffer.length == 0 || !package ||
+	    package->type != ACPI_TYPE_PACKAGE || !package->package.count)
+		goto err;
+
+	list->count = package->package.count;
+	list->handles = kzalloc_objs(*list->handles, list->count);
+	if (!list->handles)
+		goto err_clear;
+
+	/* Extract package data. */
+
+	for (i = 0; i < list->count; i++) {
+		union acpi_object *element = &(package->package.elements[i]);
+
+		if (element->type != ACPI_TYPE_LOCAL_REFERENCE ||
+		    !element->reference.handle)
+			goto err_free;
+
+		/* Get the  acpi_handle. */
+
+		list->handles[i] = element->reference.handle;
+		acpi_handle_debug(list->handles[i], "Found in reference list\n");
+	}
+
+	ret = true;
+
+end:
+	kfree(buffer.pointer);
+
+	return ret;
+
+err_free:
+	kfree(list->handles);
+	list->handles = NULL;
+
+err_clear:
+	list->count = 0;
+
+err:
+	acpi_util_eval_error(handle, pathname, status);
+	goto end;
+}
+
+EXPORT_SYMBOL(acpi_evaluate_reference);
+
+/**
+ * acpi_handle_list_equal - Check if two ACPI handle lists are the same
+ * @list1: First list to compare.
+ * @list2: Second list to compare.
+ *
+ * Return true if the given ACPI handle lists are of the same size and
+ * contain the same ACPI handles in the same order.  Otherwise, return false.
+ */
+bool acpi_handle_list_equal(struct acpi_handle_list *list1,
+			    struct acpi_handle_list *list2)
+{
+	return list1->count == list2->count &&
+		!memcmp(list1->handles, list2->handles,
+		        list1->count * sizeof(*list1->handles));
+}
+EXPORT_SYMBOL_GPL(acpi_handle_list_equal);
+
+/**
+ * acpi_handle_list_replace - Replace one ACPI handle list with another
+ * @dst: ACPI handle list to replace.
+ * @src: Source ACPI handle list.
+ *
+ * Free the handles table in @dst, move the handles table from @src to @dst,
+ * copy count from @src to @dst and clear @src.
+ */
+void acpi_handle_list_replace(struct acpi_handle_list *dst,
+			      struct acpi_handle_list *src)
+{
+	if (dst->count)
+		kfree(dst->handles);
+
+	dst->count = src->count;
+	dst->handles = src->handles;
+
+	src->handles = NULL;
+	src->count = 0;
+}
+EXPORT_SYMBOL_GPL(acpi_handle_list_replace);
+
+/**
+ * acpi_handle_list_free - Free the handles table in an ACPI handle list
+ * @list: ACPI handle list to free.
+ *
+ * Free the handles table in @list and clear its count field.
+ */
+void acpi_handle_list_free(struct acpi_handle_list *list)
+{
+	if (!list->count)
+		return;
+
+	kfree(list->handles);
+	list->count = 0;
+}
+EXPORT_SYMBOL_GPL(acpi_handle_list_free);
+
+/**
+ * acpi_device_dep - Check ACPI device dependency
+ * @target: ACPI handle of the target ACPI device.
+ * @match: ACPI handle to look up in the target's _DEP list.
+ *
+ * Return true if @match is present in the list returned by _DEP for
+ * @target or false otherwise.
+ */
+bool acpi_device_dep(acpi_handle target, acpi_handle match)
+{
+	struct acpi_handle_list dep_devices;
+	bool ret = false;
+	int i;
+
+	if (!acpi_has_method(target, "_DEP"))
+		return false;
+
+	if (!acpi_evaluate_reference(target, "_DEP", NULL, &dep_devices)) {
+		acpi_handle_debug(target, "Failed to evaluate _DEP.\n");
+		return false;
+	}
+
+	for (i = 0; i < dep_devices.count; i++) {
+		if (dep_devices.handles[i] == match) {
+			ret = true;
+			break;
+		}
+	}
+
+	acpi_handle_list_free(&dep_devices);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(acpi_device_dep);
+
+bool
+acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld)
+{
+	acpi_status status;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *output;
+
+	status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer);
+	if (ACPI_FAILURE(status))
+		return false;
+
+	output = buffer.pointer;
+
+	if (!output || output->type != ACPI_TYPE_PACKAGE
+	    || !output->package.count
+	    || output->package.elements[0].type != ACPI_TYPE_BUFFER
+	    || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) {
+		status = AE_TYPE;
+		goto out;
+	}
+
+	status = acpi_decode_pld_buffer(
+			output->package.elements[0].buffer.pointer,
+			output->package.elements[0].buffer.length,
+			pld);
+
+out:
+	kfree(buffer.pointer);
+	return ACPI_SUCCESS(status);
+}
+EXPORT_SYMBOL(acpi_get_physical_device_location);
+
+/**
+ * acpi_evaluate_ost: Evaluate _OST for hotplug operations
+ * @handle: ACPI device handle
+ * @source_event: source event code
+ * @status_code: status code
+ * @status_buf: optional detailed information (NULL if none)
+ *
+ * Evaluate _OST for hotplug operations. All ACPI hotplug handlers
+ * must call this function when evaluating _OST for hotplug operations.
+ * When the platform does not support _OST, this function has no effect.
+ */
+acpi_status
+acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
+		  struct acpi_buffer *status_buf)
+{
+	union acpi_object params[3] = {
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_BUFFER,}
+	};
+	struct acpi_object_list arg_list = {3, params};
+
+	params[0].integer.value = source_event;
+	params[1].integer.value = status_code;
+	if (status_buf != NULL) {
+		params[2].buffer.pointer = status_buf->pointer;
+		params[2].buffer.length = status_buf->length;
+	} else {
+		params[2].buffer.pointer = NULL;
+		params[2].buffer.length = 0;
+	}
+
+	return acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
+}
+EXPORT_SYMBOL(acpi_evaluate_ost);
+
+/**
+ * acpi_handle_path: Return the object path of handle
+ * @handle: ACPI device handle
+ *
+ * Caller must free the returned buffer
+ */
+char *acpi_handle_path(acpi_handle handle)
+{
+	struct acpi_buffer buffer = {
+		.length = ACPI_ALLOCATE_BUFFER,
+		.pointer = NULL
+	};
+
+	if (in_interrupt() ||
+	    acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)
+		return NULL;
+	return buffer.pointer;
+}
+
+/**
+ * acpi_handle_printk: Print message with ACPI prefix and object path
+ * @level: log level
+ * @handle: ACPI device handle
+ * @fmt: format string
+ *
+ * This function is called through acpi_handle_<level> macros and prints
+ * a message with ACPI prefix and object path.  This function acquires
+ * the global namespace mutex to obtain an object path.  In interrupt
+ * context, it shows the object path as <n/a>.
+ */
+void
+acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+	const char *path;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	path = acpi_handle_path(handle);
+	printk("%sACPI: %s: %pV", level, path ? path : "<n/a>", &vaf);
+
+	va_end(args);
+	kfree(path);
+}
+EXPORT_SYMBOL(acpi_handle_printk);
+
+#if defined(CONFIG_DYNAMIC_DEBUG)
+/**
+ * __acpi_handle_debug: pr_debug with ACPI prefix and object path
+ * @descriptor: Dynamic Debug descriptor
+ * @handle: ACPI device handle
+ * @fmt: format string
+ *
+ * This function is called through acpi_handle_debug macro and debug
+ * prints a message with ACPI prefix and object path. This function
+ * acquires the global namespace mutex to obtain an object path.  In
+ * interrupt context, it shows the object path as <n/a>.
+ */
+void
+__acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,
+		    const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+	const char *path;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	path = acpi_handle_path(handle);
+	__dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);
+
+	va_end(args);
+	kfree(path);
+}
+EXPORT_SYMBOL(__acpi_handle_debug);
+#endif
+
+/**
+ * acpi_evaluation_failure_warn - Log evaluation failure warning.
+ * @handle: Parent object handle.
+ * @name: Name of the object whose evaluation has failed.
+ * @status: Status value returned by the failing object evaluation.
+ */
+void acpi_evaluation_failure_warn(acpi_handle handle, const char *name,
+				  acpi_status status)
+{
+	acpi_handle_warn(handle, "%s evaluation failed: %s\n", name,
+			 acpi_format_exception(status));
+}
+EXPORT_SYMBOL_GPL(acpi_evaluation_failure_warn);
+
+/**
+ * acpi_has_method: Check whether @handle has a method named @name
+ * @handle: ACPI device handle
+ * @name: name of object or method
+ *
+ * Check whether @handle has a method named @name.
+ */
+bool acpi_has_method(acpi_handle handle, char *name)
+{
+	acpi_handle tmp;
+
+	return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));
+}
+EXPORT_SYMBOL(acpi_has_method);
+
+acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
+				       u64 arg)
+{
+	union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
+	struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };
+
+	obj.integer.value = arg;
+
+	return acpi_evaluate_object(handle, method, &arg_list, NULL);
+}
+EXPORT_SYMBOL(acpi_execute_simple_method);
+
+/**
+ * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
+ * @handle: ACPI device handle
+ *
+ * Evaluate device's _EJ0 method for hotplug operations.
+ */
+acpi_status acpi_evaluate_ej0(acpi_handle handle)
+{
+	acpi_status status;
+
+	status = acpi_execute_simple_method(handle, "_EJ0", 1);
+	if (status == AE_NOT_FOUND)
+		acpi_handle_warn(handle, "No _EJ0 support for device\n");
+	else if (ACPI_FAILURE(status))
+		acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);
+
+	return status;
+}
+
+/**
+ * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
+ * @handle: ACPI device handle
+ * @lock: lock device if non-zero, otherwise unlock device
+ *
+ * Evaluate device's _LCK method if present to lock/unlock device
+ */
+acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
+{
+	acpi_status status;
+
+	status = acpi_execute_simple_method(handle, "_LCK", !!lock);
+	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+		if (lock)
+			acpi_handle_warn(handle,
+				"Locking device failed (0x%x)\n", status);
+		else
+			acpi_handle_warn(handle,
+				"Unlocking device failed (0x%x)\n", status);
+	}
+
+	return status;
+}
+
+/**
+ * acpi_evaluate_reg: Evaluate _REG method to register OpRegion presence
+ * @handle: ACPI device handle
+ * @space_id: ACPI address space id to register OpRegion presence for
+ * @function: Parameter to pass to _REG one of ACPI_REG_CONNECT or
+ *            ACPI_REG_DISCONNECT
+ *
+ * Evaluate device's _REG method to register OpRegion presence.
+ */
+acpi_status acpi_evaluate_reg(acpi_handle handle, u8 space_id, u32 function)
+{
+	struct acpi_object_list arg_list;
+	union acpi_object params[2];
+
+	params[0].type = ACPI_TYPE_INTEGER;
+	params[0].integer.value = space_id;
+	params[1].type = ACPI_TYPE_INTEGER;
+	params[1].integer.value = function;
+	arg_list.count = 2;
+	arg_list.pointer = params;
+
+	return acpi_evaluate_object(handle, "_REG", &arg_list, NULL);
+}
+EXPORT_SYMBOL(acpi_evaluate_reg);
+
+/**
+ * acpi_evaluate_dsm - evaluate device's _DSM method
+ * @handle: ACPI device handle
+ * @guid: GUID of requested functions, should be 16 bytes
+ * @rev: revision number of requested function
+ * @func: requested function number
+ * @argv4: the function specific parameter
+ *
+ * Evaluate device's _DSM method with specified GUID, revision id and
+ * function number. Caller needs to free the returned object.
+ *
+ * Though ACPI defines the fourth parameter for _DSM should be a package,
+ * some old BIOSes do expect a buffer or an integer etc.
+ */
+union acpi_object *
+acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 func,
+		  union acpi_object *argv4)
+{
+	acpi_status ret;
+	struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
+	union acpi_object params[4];
+	struct acpi_object_list input = {
+		.count = 4,
+		.pointer = params,
+	};
+
+	params[0].type = ACPI_TYPE_BUFFER;
+	params[0].buffer.length = 16;
+	params[0].buffer.pointer = (u8 *)guid;
+	params[1].type = ACPI_TYPE_INTEGER;
+	params[1].integer.value = rev;
+	params[2].type = ACPI_TYPE_INTEGER;
+	params[2].integer.value = func;
+	if (argv4) {
+		params[3] = *argv4;
+	} else {
+		params[3].type = ACPI_TYPE_PACKAGE;
+		params[3].package.count = 0;
+		params[3].package.elements = NULL;
+	}
+
+	ret = acpi_evaluate_object(handle, "_DSM", &input, &buf);
+	if (ACPI_SUCCESS(ret))
+		return (union acpi_object *)buf.pointer;
+
+	if (ret != AE_NOT_FOUND)
+		acpi_handle_warn(handle,
+				 "failed to evaluate _DSM %pUb rev:%lld func:%lld (0x%x)\n",
+				 guid, rev, func, ret);
+
+	return NULL;
+}
+EXPORT_SYMBOL(acpi_evaluate_dsm);
+
+/**
+ * acpi_check_dsm - check if _DSM method supports requested functions.
+ * @handle: ACPI device handle
+ * @guid: GUID of requested functions, should be 16 bytes at least
+ * @rev: revision number of requested functions
+ * @funcs: bitmap of requested functions
+ *
+ * Evaluate device's _DSM method to check whether it supports requested
+ * functions. Currently only support 64 functions at maximum, should be
+ * enough for now.
+ */
+bool acpi_check_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 funcs)
+{
+	int i;
+	u64 mask = 0;
+	union acpi_object *obj;
+
+	if (funcs == 0)
+		return false;
+
+	obj = acpi_evaluate_dsm(handle, guid, rev, 0, NULL);
+	if (!obj)
+		return false;
+
+	/* For compatibility, old BIOSes may return an integer */
+	if (obj->type == ACPI_TYPE_INTEGER)
+		mask = obj->integer.value;
+	else if (obj->type == ACPI_TYPE_BUFFER)
+		for (i = 0; i < obj->buffer.length && i < 8; i++)
+			mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
+	ACPI_FREE(obj);
+
+	/*
+	 * Bit 0 indicates whether there's support for any functions other than
+	 * function 0 for the specified GUID and revision.
+	 */
+	if ((mask & 0x1) && (mask & funcs) == funcs)
+		return true;
+
+	return false;
+}
+EXPORT_SYMBOL(acpi_check_dsm);
+
+/**
+ * acpi_dev_uid_to_integer - treat ACPI device _UID as integer
+ * @adev: ACPI device to get _UID from
+ * @integer: output buffer for integer
+ *
+ * Considers _UID as integer and converts it to @integer.
+ *
+ * Returns 0 on success, or negative error code otherwise.
+ */
+int acpi_dev_uid_to_integer(struct acpi_device *adev, u64 *integer)
+{
+	const char *uid;
+
+	if (!adev)
+		return -ENODEV;
+
+	uid = acpi_device_uid(adev);
+	if (!uid)
+		return -ENODATA;
+
+	return kstrtou64(uid, 0, integer);
+}
+EXPORT_SYMBOL(acpi_dev_uid_to_integer);
+
+/**
+ * acpi_dev_found - Detect presence of a given ACPI device in the namespace.
+ * @hid: Hardware ID of the device.
+ *
+ * Return %true if the device was present at the moment of invocation.
+ * Note that if the device is pluggable, it may since have disappeared.
+ *
+ * For this function to work, acpi_bus_scan() must have been executed
+ * which happens in the subsys_initcall() subsection. Hence, do not
+ * call from a subsys_initcall() or earlier (use acpi_get_devices()
+ * instead). Calling from module_init() is fine (which is synonymous
+ * with device_initcall()).
+ */
+bool acpi_dev_found(const char *hid)
+{
+	struct acpi_device_bus_id *acpi_device_bus_id;
+	bool found = false;
+
+	mutex_lock(&acpi_device_lock);
+	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
+		if (!strcmp(acpi_device_bus_id->bus_id, hid)) {
+			found = true;
+			break;
+		}
+	mutex_unlock(&acpi_device_lock);
+
+	return found;
+}
+EXPORT_SYMBOL(acpi_dev_found);
+
+struct acpi_dev_match_info {
+	struct acpi_device_id hid[2];
+	const char *uid;
+	s64 hrv;
+};
+
+static int acpi_dev_match_cb(struct device *dev, const void *data)
+{
+	struct acpi_device *adev = to_acpi_device(dev);
+	const struct acpi_dev_match_info *match = data;
+	unsigned long long hrv;
+	acpi_status status;
+
+	if (acpi_match_device_ids(adev, match->hid))
+		return 0;
+
+	if (match->uid && !acpi_dev_uid_match(adev, match->uid))
+		return 0;
+
+	if (match->hrv == -1)
+		return 1;
+
+	status = acpi_evaluate_integer(adev->handle, "_HRV", NULL, &hrv);
+	if (ACPI_FAILURE(status))
+		return 0;
+
+	return hrv == match->hrv;
+}
+
+/**
+ * acpi_dev_present - Detect that a given ACPI device is present
+ * @hid: Hardware ID of the device.
+ * @uid: Unique ID of the device, pass NULL to not check _UID
+ * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
+ *
+ * Return %true if a matching device was present at the moment of invocation.
+ * Note that if the device is pluggable, it may since have disappeared.
+ *
+ * Note that unlike acpi_dev_found() this function checks the status
+ * of the device. So for devices which are present in the DSDT, but
+ * which are disabled (their _STA callback returns 0) this function
+ * will return false.
+ *
+ * For this function to work, acpi_bus_scan() must have been executed
+ * which happens in the subsys_initcall() subsection. Hence, do not
+ * call from a subsys_initcall() or earlier (use acpi_get_devices()
+ * instead). Calling from module_init() is fine (which is synonymous
+ * with device_initcall()).
+ */
+bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
+{
+	struct acpi_dev_match_info match = {};
+	struct device *dev;
+
+	strscpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
+	match.uid = uid;
+	match.hrv = hrv;
+
+	dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
+	put_device(dev);
+	return !!dev;
+}
+EXPORT_SYMBOL(acpi_dev_present);
+
+/**
+ * acpi_dev_get_next_match_dev - Return the next match of ACPI device
+ * @adev: Pointer to the previous ACPI device matching this @hid, @uid and @hrv
+ * @hid: Hardware ID of the device.
+ * @uid: Unique ID of the device, pass NULL to not check _UID
+ * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
+ *
+ * Return the next match of ACPI device if another matching device was present
+ * at the moment of invocation, or NULL otherwise.
+ *
+ * The caller is responsible for invoking acpi_dev_put() on the returned device.
+ * On the other hand the function invokes  acpi_dev_put() on the given @adev
+ * assuming that its reference counter had been increased beforehand.
+ *
+ * See additional information in acpi_dev_present() as well.
+ */
+struct acpi_device *
+acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const char *uid, s64 hrv)
+{
+	struct device *start = adev ? &adev->dev : NULL;
+	struct acpi_dev_match_info match = {};
+	struct device *dev;
+
+	strscpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
+	match.uid = uid;
+	match.hrv = hrv;
+
+	dev = bus_find_device(&acpi_bus_type, start, &match, acpi_dev_match_cb);
+	acpi_dev_put(adev);
+	return dev ? to_acpi_device(dev) : NULL;
+}
+EXPORT_SYMBOL(acpi_dev_get_next_match_dev);
+
+/**
+ * acpi_dev_get_first_match_dev - Return the first match of ACPI device
+ * @hid: Hardware ID of the device.
+ * @uid: Unique ID of the device, pass NULL to not check _UID
+ * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
+ *
+ * Return the first match of ACPI device if a matching device was present
+ * at the moment of invocation, or NULL otherwise.
+ *
+ * The caller is responsible for invoking acpi_dev_put() on the returned device.
+ *
+ * See additional information in acpi_dev_present() as well.
+ */
+struct acpi_device *
+acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)
+{
+	return acpi_dev_get_next_match_dev(NULL, hid, uid, hrv);
+}
+EXPORT_SYMBOL(acpi_dev_get_first_match_dev);
+
+/**
+ * acpi_reduced_hardware - Return if this is an ACPI-reduced-hw machine
+ *
+ * Return true when running on an ACPI-reduced-hw machine, false otherwise.
+ */
+bool acpi_reduced_hardware(void)
+{
+	return acpi_gbl_reduced_hardware;
+}
+EXPORT_SYMBOL_GPL(acpi_reduced_hardware);
+
+/*
+ * acpi_backlight= handling, this is done here rather then in video_detect.c
+ * because __setup cannot be used in modules.
+ */
+char acpi_video_backlight_string[16];
+EXPORT_SYMBOL(acpi_video_backlight_string);
+
+static int __init acpi_backlight(char *str)
+{
+	strscpy(acpi_video_backlight_string, str,
+		sizeof(acpi_video_backlight_string));
+	return 1;
+}
+__setup("acpi_backlight=", acpi_backlight);
+
+/**
+ * acpi_dev_is_video_device - test if device matches against ACPI video device IDs
+ * @adev: ACPI device to test
+ *
+ * Return: true when matches, otherwise false.
+ */
+bool acpi_dev_is_video_device(struct acpi_device *adev)
+{
+	static const struct acpi_device_id video_device_ids[] = {
+		{ .id = ACPI_VIDEO_HID },
+		{ }
+	};
+
+	return adev && !acpi_match_device_ids(adev, video_device_ids);
+}
+EXPORT_SYMBOL(acpi_dev_is_video_device);
+
+/**
+ * acpi_match_platform_list - Check if the system matches with a given list
+ * @plat: pointer to acpi_platform_list table terminated by a NULL entry
+ *
+ * Return the matched index if the system is found in the platform list.
+ * Otherwise, return a negative error code.
+ */
+int acpi_match_platform_list(const struct acpi_platform_list *plat)
+{
+	struct acpi_table_header hdr;
+	int idx = 0;
+
+	if (acpi_disabled)
+		return -ENODEV;
+
+	for (; plat->oem_id[0]; plat++, idx++) {
+		if (ACPI_FAILURE(acpi_get_table_header(plat->table, 0, &hdr)))
+			continue;
+
+		if (strncmp(plat->oem_id, hdr.oem_id, ACPI_OEM_ID_SIZE))
+			continue;
+
+		if (strncmp(plat->oem_table_id, hdr.oem_table_id, ACPI_OEM_TABLE_ID_SIZE))
+			continue;
+
+		if ((plat->pred == all_versions) ||
+		    (plat->pred == less_than_or_equal && hdr.oem_revision <= plat->oem_revision) ||
+		    (plat->pred == greater_than_or_equal && hdr.oem_revision >= plat->oem_revision) ||
+		    (plat->pred == equal && hdr.oem_revision == plat->oem_revision))
+			return idx;
+	}
+
+	return -ENODEV;
+}
+EXPORT_SYMBOL(acpi_match_platform_list);