/*

 * Copyright (c) 2013-2017, Intel Corporation

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 *  * Redistributions of source code must retain the above copyright notice,

 *    this list of conditions and the following disclaimer.

 *  * Redistributions in binary form must reproduce the above copyright notice,

 *    this list of conditions and the following disclaimer in the documentation

 *    and/or other materials provided with the distribution.

 *  * Neither the name of Intel Corporation nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGE.

 */

#include "pt_section.h"

#include "pt_section_file.h"

#include "intel-pt.h"

#include <stdlib.h>

#include <string.h>

static int fmap_init(struct pt_sec_file_mapping *mapping)

{

	if (!mapping)

		return -pte_internal;

	memset(mapping, 0, sizeof(*mapping));

#if defined(FEATURE_THREADS)

	{

		int errcode;

		errcode = mtx_init(&mapping->lock, mtx_plain);

		if (errcode != thrd_success)

			return -pte_bad_lock;

	}

#endif /* defined(FEATURE_THREADS) */

	return 0;

}

static void fmap_fini(struct pt_sec_file_mapping *mapping)

{

	if (!mapping)

		return;

	fclose(mapping->file);

#if defined(FEATURE_THREADS)

	mtx_destroy(&mapping->lock);

#endif /* defined(FEATURE_THREADS) */

}

static int fmap_lock(struct pt_sec_file_mapping *mapping)

{

	if (!mapping)

		return -pte_internal;

#if defined(FEATURE_THREADS)

	{

		int errcode;

		errcode = mtx_lock(&mapping->lock);

		if (errcode != thrd_success)

			return -pte_bad_lock;

	}

#endif /* defined(FEATURE_THREADS) */

	return 0;

}

static int fmap_unlock(struct pt_sec_file_mapping *mapping)

{

	if (!mapping)

		return -pte_internal;

#if defined(FEATURE_THREADS)

	{

		int errcode;

		errcode = mtx_unlock(&mapping->lock);

		if (errcode != thrd_success)

			return -pte_bad_lock;

	}

#endif /* defined(FEATURE_THREADS) */

	return 0;

}

int pt_sec_file_map(struct pt_section *section, FILE *file)

{

	struct pt_sec_file_mapping *mapping;

	uint64_t offset, size;

	long begin, end, fsize;

	int errcode;

	if (!section)

		return -pte_internal;

	mapping = section->mapping;

	if (mapping)

		return -pte_internal;

	offset = section->offset;

	size = section->size;

	begin = (long) offset;

	end = begin + (long) size;

	/* Check for overflows. */

	if ((uint64_t) begin != offset)

		return -pte_bad_image;

	if ((uint64_t) end != (offset + size))

		return -pte_bad_image;

	if (end < begin)

		return -pte_bad_image;

	/* Validate that the section lies within the file. */

	errcode = fseek(file, 0, SEEK_END);

	if (errcode)

		return -pte_bad_image;

	fsize = ftell(file);

	if (fsize < 0)

		return -pte_bad_image;

	if (fsize < end)

		return -pte_bad_image;

	mapping = malloc(sizeof(*mapping));

	if (!mapping)

		return -pte_nomem;

	errcode = fmap_init(mapping);

	if (errcode < 0) {

		free(mapping);

		return errcode;

	}

	mapping->file = file;

	mapping->begin = begin;

	mapping->end = end;

	section->mapping = mapping;

	section->unmap = pt_sec_file_unmap;

	section->read = pt_sec_file_read;

	return pt_section_add_bcache(section);

}

int pt_sec_file_unmap(struct pt_section *section)

{

	struct pt_sec_file_mapping *mapping;

	if (!section)

		return -pte_internal;

	mapping = section->mapping;

	if (!mapping || !section->unmap || !section->read)

		return -pte_internal;

	section->mapping = NULL;

	section->unmap = NULL;

	section->read = NULL;

	fmap_fini(mapping);

	free(mapping);

	return 0;

}

int pt_sec_file_read(const struct pt_section *section, uint8_t *buffer,

		     uint16_t size, uint64_t offset)

{

	struct pt_sec_file_mapping *mapping;

	FILE *file;

	long begin;

	size_t read;

	int errcode;

	if (!buffer || !section)

		return -pte_internal;

	mapping = section->mapping;

	if (!mapping)

		return -pte_internal;

	file = mapping->file;

	/* We already checked in pt_section_read() that the requested memory

	 * lies within the section's boundaries.

	 *

	 * And we checked that the file covers the entire section in

	 * pt_sec_file_map().  There's no need to check for overflows, again.

	 */

	begin = mapping->begin + (long) offset;

	errcode = fmap_lock(mapping);

	if (errcode < 0)

		return errcode;

	errcode = fseek(file, begin, SEEK_SET);

	if (errcode)

		goto out_unlock;

	read = fread(buffer, 1, size, file);

	errcode = fmap_unlock(mapping);

	if (errcode < 0)

		return errcode;

	return (int) read;

out_unlock:

	(void) fmap_unlock(mapping);

	return -pte_nomap;

}