/** * Copyright (c) 2016-present, Yann Collet, Facebook, Inc. * All rights reserved. * * This source code is licensed under the BSD-style license found in the * LICENSE file in the root directory of https://github.com/facebook/zstd. * An additional grant of patent rights can be found in the PATENTS file in the * same directory. * * This program is free software; you can redistribute it and/or modify it under * the terms of the GNU General Public License version 2 as published by the * Free Software Foundation. This program is dual-licensed; you may select * either version 2 of the GNU General Public License ("GPL") or BSD license * ("BSD"). */ /*-**************************************  Dependencies***************************************/#include "error_private.h"#include "zstd_internal.h" /* declaration of ZSTD_isError, ZSTD_getErrorName, ZSTD_getErrorCode, ZSTD_getErrorString, ZSTD_versionNumber */#include <linux/kernel.h> /*=***************************************************************  Custom allocator****************************************************************/ #define stack_push(stack, size)                                 \	({                                                      \		void *const ptr = ZSTD_PTR_ALIGN((stack)->ptr); \		(stack)->ptr = (char *)ptr + (size);            \		(stack)->ptr <= (stack)->end ? ptr : NULL;      \	}) ZSTD_customMem ZSTD_initStack(void *workspace, size_t workspaceSize){	ZSTD_customMem stackMem = {ZSTD_stackAlloc, ZSTD_stackFree, workspace};	ZSTD_stack *stack = (ZSTD_stack *)workspace;	/* Verify preconditions */	if (!workspace || workspaceSize < sizeof(ZSTD_stack) || workspace != ZSTD_PTR_ALIGN(workspace)) {		ZSTD_customMem error = {NULL, NULL, NULL};		return error;	}	/* Initialize the stack */	stack->ptr = workspace;	stack->end = (char *)workspace + workspaceSize;	stack_push(stack, sizeof(ZSTD_stack));	return stackMem;} void *ZSTD_stackAllocAll(void *opaque, size_t *size){	ZSTD_stack *stack = (ZSTD_stack *)opaque;	*size = (BYTE const *)stack->end - (BYTE *)ZSTD_PTR_ALIGN(stack->ptr);	return stack_push(stack, *size);} void *ZSTD_stackAlloc(void *opaque, size_t size){	ZSTD_stack *stack = (ZSTD_stack *)opaque;	return stack_push(stack, size);}void ZSTD_stackFree(void *opaque, void *address){	(void)opaque;	(void)address;} void *ZSTD_malloc(size_t size, ZSTD_customMem customMem) { return customMem.customAlloc(customMem.opaque, size); } void ZSTD_free(void *ptr, ZSTD_customMem customMem){	if (ptr != NULL)		customMem.customFree(customMem.opaque, ptr);}