drivers/remoteproc/remoteproc_coredump.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Coredump functionality for Remoteproc framework.
  *
  * Copyright (c) 2020, The Linux Foundation. All rights reserved.
  */

 #include <linux/completion.h>
 #include <linux/devcoredump.h>
 #include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/remoteproc.h>
 #include "remoteproc_internal.h"
 #include "remoteproc_elf_helpers.h"

 struct rproc_coredump_state {
 	struct rproc *rproc;
 	void *header;
 	struct completion dump_done;
 };

 /**
  * rproc_coredump_cleanup() - clean up dump_segments list
  * @rproc: the remote processor handle
  */
 void rproc_coredump_cleanup(struct rproc *rproc)
 {
 	struct rproc_dump_segment *entry, *tmp;

 	list_for_each_entry_safe(entry, tmp, &rproc->dump_segments, node) {
 		list_del(&entry->node);
 		kfree(entry);
 	}
 }
 EXPORT_SYMBOL_GPL(rproc_coredump_cleanup);

 /**
  * rproc_coredump_add_segment() - add segment of device memory to coredump
  * @rproc:	handle of a remote processor
  * @da:		device address
  * @size:	size of segment
  *
  * Add device memory to the list of segments to be included in a coredump for
  * the remoteproc.
  *
  * Return: 0 on success, negative errno on error.
  */
 int rproc_coredump_add_segment(struct rproc *rproc, dma_addr_t da, size_t size)
 {
 	struct rproc_dump_segment *segment;

 	segment = kzalloc(sizeof(*segment), GFP_KERNEL);
 	if (!segment)
 		return -ENOMEM;

 	segment->da = da;
 	segment->size = size;

 	list_add_tail(&segment->node, &rproc->dump_segments);

 	return 0;
 }
 EXPORT_SYMBOL(rproc_coredump_add_segment);

 /**
  * rproc_coredump_add_custom_segment() - add custom coredump segment
  * @rproc:	handle of a remote processor
  * @da:		device address
  * @size:	size of segment
  * @dumpfn:	custom dump function called for each segment during coredump
  * @priv:	private data
  *
  * Add device memory to the list of segments to be included in the coredump
  * and associate the segment with the given custom dump function and private
  * data.
  *
  * Return: 0 on success, negative errno on error.
  */
 int rproc_coredump_add_custom_segment(struct rproc *rproc,
 				      dma_addr_t da, size_t size,
 				      void (*dumpfn)(struct rproc *rproc,
 						     struct rproc_dump_segment *segment,
 						     void *dest, size_t offset,
 						     size_t size),
 				      void *priv)
 {
 	struct rproc_dump_segment *segment;

 	segment = kzalloc(sizeof(*segment), GFP_KERNEL);
 	if (!segment)
 		return -ENOMEM;

 	segment->da = da;
 	segment->size = size;
 	segment->priv = priv;
 	segment->dump = dumpfn;

 	list_add_tail(&segment->node, &rproc->dump_segments);

 	return 0;
 }
 EXPORT_SYMBOL(rproc_coredump_add_custom_segment);

 /**
  * rproc_coredump_set_elf_info() - set coredump elf information
  * @rproc:	handle of a remote processor
  * @class:	elf class for coredump elf file
  * @machine:	elf machine for coredump elf file
  *
  * Set elf information which will be used for coredump elf file.
  *
  * Return: 0 on success, negative errno on error.
  */
 int rproc_coredump_set_elf_info(struct rproc *rproc, u8 class, u16 machine)
 {
 	if (class != ELFCLASS64 && class != ELFCLASS32)
 		return -EINVAL;

 	rproc->elf_class = class;
 	rproc->elf_machine = machine;

 	return 0;
 }
 EXPORT_SYMBOL(rproc_coredump_set_elf_info);

 static void rproc_coredump_free(void *data)
 {
 	struct rproc_coredump_state *dump_state = data;

 	vfree(dump_state->header);
 	complete(&dump_state->dump_done);
 }

 static void *rproc_coredump_find_segment(loff_t user_offset,
 					 struct list_head *segments,
 					 size_t *data_left)
 {
 	struct rproc_dump_segment *segment;

 	list_for_each_entry(segment, segments, node) {
 		if (user_offset < segment->size) {
 			*data_left = segment->size - user_offset;
 			return segment;
 		}
 		user_offset -= segment->size;
 	}

 	*data_left = 0;
 	return NULL;
 }

 static void rproc_copy_segment(struct rproc *rproc, void *dest,
 			       struct rproc_dump_segment *segment,
 			       size_t offset, size_t size)
 {
 	bool is_iomem = false;
 	void *ptr;

 	if (segment->dump) {
 		segment->dump(rproc, segment, dest, offset, size);
 	} else {
 		ptr = rproc_da_to_va(rproc, segment->da + offset, size, &is_iomem);
 		if (!ptr) {
 			dev_err(&rproc->dev,
 				"invalid copy request for segment %pad with offset %zu and size %zu)\n",
 				&segment->da, offset, size);
 			memset(dest, 0xff, size);
 		} else {
 			if (is_iomem)
 				memcpy_fromio(dest, (void const __iomem *)ptr, size);
 			else
 				memcpy(dest, ptr, size);
 		}
 	}
 }

 static ssize_t rproc_coredump_read(char *buffer, loff_t offset, size_t count,
 				   void *data, size_t header_sz)
 {
 	size_t seg_data, bytes_left = count;
 	ssize_t copy_sz;
 	struct rproc_dump_segment *seg;
 	struct rproc_coredump_state *dump_state = data;
 	struct rproc *rproc = dump_state->rproc;
 	void *elfcore = dump_state->header;

 	/* Copy the vmalloc'ed header first. */
 	if (offset < header_sz) {
 		copy_sz = memory_read_from_buffer(buffer, count, &offset,
 						  elfcore, header_sz);

 		return copy_sz;
 	}

 	/*
 	 * Find out the segment memory chunk to be copied based on offset.
 	 * Keep copying data until count bytes are read.
 	 */
 	while (bytes_left) {
 		seg = rproc_coredump_find_segment(offset - header_sz,
 						  &rproc->dump_segments,
 						  &seg_data);
 		/* EOF check */
 		if (!seg) {
 			dev_info(&rproc->dev, "Ramdump done, %lld bytes read",
 				 offset);
 			break;
 		}

 		copy_sz = min_t(size_t, bytes_left, seg_data);

 		rproc_copy_segment(rproc, buffer, seg, seg->size - seg_data,
 				   copy_sz);

 		offset += copy_sz;
 		buffer += copy_sz;
 		bytes_left -= copy_sz;
 	}

 	return count - bytes_left;
 }

 /**
  * rproc_coredump() - perform coredump
  * @rproc:	rproc handle
  *
  * This function will generate an ELF header for the registered segments
  * and create a devcoredump device associated with rproc. Based on the
  * coredump configuration this function will directly copy the segments
  * from device memory to userspace or copy segments from device memory to
  * a separate buffer, which can then be read by userspace.
  * The first approach avoids using extra vmalloc memory. But it will stall
  * recovery flow until dump is read by userspace.
  */
 void rproc_coredump(struct rproc *rproc)
 {
 	struct rproc_dump_segment *segment;
 	void *phdr;
 	void *ehdr;
 	size_t data_size;
 	size_t offset;
 	void *data;
 	u8 class = rproc->elf_class;
 	int phnum = 0;
 	struct rproc_coredump_state dump_state;
 	enum rproc_dump_mechanism dump_conf = rproc->dump_conf;

 	if (list_empty(&rproc->dump_segments) ||
 	    dump_conf == RPROC_COREDUMP_DISABLED)
 		return;

 	if (class == ELFCLASSNONE) {
 		dev_err(&rproc->dev, "ELF class is not set\n");
 		return;
 	}

 	data_size = elf_size_of_hdr(class);
 	list_for_each_entry(segment, &rproc->dump_segments, node) {
 		/*
 		 * For default configuration buffer includes headers & segments.
 		 * For inline dump buffer just includes headers as segments are
 		 * directly read from device memory.
 		 */
 		data_size += elf_size_of_phdr(class);
 		if (dump_conf == RPROC_COREDUMP_ENABLED)
 			data_size += segment->size;

 		phnum++;
 	}

 	data = vmalloc(data_size);
 	if (!data)
 		return;

 	ehdr = data;

 	memset(ehdr, 0, elf_size_of_hdr(class));
 	/* e_ident field is common for both elf32 and elf64 */
 	elf_hdr_init_ident(ehdr, class);

 	elf_hdr_set_e_type(class, ehdr, ET_CORE);
 	elf_hdr_set_e_machine(class, ehdr, rproc->elf_machine);
 	elf_hdr_set_e_version(class, ehdr, EV_CURRENT);
 	elf_hdr_set_e_entry(class, ehdr, rproc->bootaddr);
 	elf_hdr_set_e_phoff(class, ehdr, elf_size_of_hdr(class));
 	elf_hdr_set_e_ehsize(class, ehdr, elf_size_of_hdr(class));
 	elf_hdr_set_e_phentsize(class, ehdr, elf_size_of_phdr(class));
 	elf_hdr_set_e_phnum(class, ehdr, phnum);

 	phdr = data + elf_hdr_get_e_phoff(class, ehdr);
 	offset = elf_hdr_get_e_phoff(class, ehdr);
 	offset += elf_size_of_phdr(class) * elf_hdr_get_e_phnum(class, ehdr);

 	list_for_each_entry(segment, &rproc->dump_segments, node) {
 		memset(phdr, 0, elf_size_of_phdr(class));
 		elf_phdr_set_p_type(class, phdr, PT_LOAD);
 		elf_phdr_set_p_offset(class, phdr, offset);
 		elf_phdr_set_p_vaddr(class, phdr, segment->da);
 		elf_phdr_set_p_paddr(class, phdr, segment->da);
 		elf_phdr_set_p_filesz(class, phdr, segment->size);
 		elf_phdr_set_p_memsz(class, phdr, segment->size);
 		elf_phdr_set_p_flags(class, phdr, PF_R | PF_W | PF_X);
 		elf_phdr_set_p_align(class, phdr, 0);

 		if (dump_conf == RPROC_COREDUMP_ENABLED)
 			rproc_copy_segment(rproc, data + offset, segment, 0,
 					   segment->size);

 		offset += elf_phdr_get_p_filesz(class, phdr);
 		phdr += elf_size_of_phdr(class);
 	}
 	if (dump_conf == RPROC_COREDUMP_ENABLED) {
 		dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL);
 		return;
 	}

 	/* Initialize the dump state struct to be used by rproc_coredump_read */
 	dump_state.rproc = rproc;
 	dump_state.header = data;
 	init_completion(&dump_state.dump_done);

 	dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL,
 		      rproc_coredump_read, rproc_coredump_free);

 	/*
 	 * Wait until the dump is read and free is called. Data is freed
 	 * by devcoredump framework automatically after 5 minutes.
 	 */
 	wait_for_completion(&dump_state.dump_done);
 }
 EXPORT_SYMBOL_GPL(rproc_coredump);

 /**
  * rproc_coredump_using_sections() - perform coredump using section headers
  * @rproc:	rproc handle
  *
  * This function will generate an ELF header for the registered sections of
  * segments and create a devcoredump device associated with rproc. Based on
  * the coredump configuration this function will directly copy the segments
  * from device memory to userspace or copy segments from device memory to
  * a separate buffer, which can then be read by userspace.
  * The first approach avoids using extra vmalloc memory. But it will stall
  * recovery flow until dump is read by userspace.
  */
 void rproc_coredump_using_sections(struct rproc *rproc)
 {
 	struct rproc_dump_segment *segment;
 	void *shdr;
 	void *ehdr;
 	size_t data_size;
 	size_t strtbl_size = 0;
 	size_t strtbl_index = 1;
 	size_t offset;
 	void *data;
 	u8 class = rproc->elf_class;
 	int shnum;
 	struct rproc_coredump_state dump_state;
 	unsigned int dump_conf = rproc->dump_conf;
 	char *str_tbl = "STR_TBL";

 	if (list_empty(&rproc->dump_segments) ||
 	    dump_conf == RPROC_COREDUMP_DISABLED)
 		return;

 	if (class == ELFCLASSNONE) {
 		dev_err(&rproc->dev, "ELF class is not set\n");
 		return;
 	}

 	/*
 	 * We allocate two extra section headers. The first one is null.
 	 * Second section header is for the string table. Also space is
 	 * allocated for string table.
 	 */
 	data_size = elf_size_of_hdr(class) + 2 * elf_size_of_shdr(class);
 	shnum = 2;

 	/* the extra byte is for the null character at index 0 */
 	strtbl_size += strlen(str_tbl) + 2;

 	list_for_each_entry(segment, &rproc->dump_segments, node) {
 		data_size += elf_size_of_shdr(class);
 		strtbl_size += strlen(segment->priv) + 1;
 		if (dump_conf == RPROC_COREDUMP_ENABLED)
 			data_size += segment->size;
 		shnum++;
 	}

 	data_size += strtbl_size;

 	data = vmalloc(data_size);
 	if (!data)
 		return;

 	ehdr = data;
 	memset(ehdr, 0, elf_size_of_hdr(class));
 	/* e_ident field is common for both elf32 and elf64 */
 	elf_hdr_init_ident(ehdr, class);

 	elf_hdr_set_e_type(class, ehdr, ET_CORE);
 	elf_hdr_set_e_machine(class, ehdr, rproc->elf_machine);
 	elf_hdr_set_e_version(class, ehdr, EV_CURRENT);
 	elf_hdr_set_e_entry(class, ehdr, rproc->bootaddr);
 	elf_hdr_set_e_shoff(class, ehdr, elf_size_of_hdr(class));
 	elf_hdr_set_e_ehsize(class, ehdr, elf_size_of_hdr(class));
 	elf_hdr_set_e_shentsize(class, ehdr, elf_size_of_shdr(class));
 	elf_hdr_set_e_shnum(class, ehdr, shnum);
 	elf_hdr_set_e_shstrndx(class, ehdr, 1);

 	/*
 	 * The zeroth index of the section header is reserved and is rarely used.
 	 * Set the section header as null (SHN_UNDEF) and move to the next one.
 	 */
 	shdr = data + elf_hdr_get_e_shoff(class, ehdr);
 	memset(shdr, 0, elf_size_of_shdr(class));
 	shdr += elf_size_of_shdr(class);

 	/* Initialize the string table. */
 	offset = elf_hdr_get_e_shoff(class, ehdr) +
 		 elf_size_of_shdr(class) * elf_hdr_get_e_shnum(class, ehdr);
 	memset(data + offset, 0, strtbl_size);

 	/* Fill in the string table section header. */
 	memset(shdr, 0, elf_size_of_shdr(class));
 	elf_shdr_set_sh_type(class, shdr, SHT_STRTAB);
 	elf_shdr_set_sh_offset(class, shdr, offset);
 	elf_shdr_set_sh_size(class, shdr, strtbl_size);
 	elf_shdr_set_sh_entsize(class, shdr, 0);
 	elf_shdr_set_sh_flags(class, shdr, 0);
 	elf_shdr_set_sh_name(class, shdr, elf_strtbl_add(str_tbl, ehdr, class, &strtbl_index));
 	offset += elf_shdr_get_sh_size(class, shdr);
 	shdr += elf_size_of_shdr(class);

 	list_for_each_entry(segment, &rproc->dump_segments, node) {
 		memset(shdr, 0, elf_size_of_shdr(class));
 		elf_shdr_set_sh_type(class, shdr, SHT_PROGBITS);
 		elf_shdr_set_sh_offset(class, shdr, offset);
 		elf_shdr_set_sh_addr(class, shdr, segment->da);
 		elf_shdr_set_sh_size(class, shdr, segment->size);
 		elf_shdr_set_sh_entsize(class, shdr, 0);
 		elf_shdr_set_sh_flags(class, shdr, SHF_WRITE);
 		elf_shdr_set_sh_name(class, shdr,
 				     elf_strtbl_add(segment->priv, ehdr, class, &strtbl_index));

 		/* No need to copy segments for inline dumps */
 		if (dump_conf == RPROC_COREDUMP_ENABLED)
 			rproc_copy_segment(rproc, data + offset, segment, 0,
 					   segment->size);
 		offset += elf_shdr_get_sh_size(class, shdr);
 		shdr += elf_size_of_shdr(class);
 	}

 	if (dump_conf == RPROC_COREDUMP_ENABLED) {
 		dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL);
 		return;
 	}

 	/* Initialize the dump state struct to be used by rproc_coredump_read */
 	dump_state.rproc = rproc;
 	dump_state.header = data;
 	init_completion(&dump_state.dump_done);

 	dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL,
 		      rproc_coredump_read, rproc_coredump_free);

 	/* Wait until the dump is read and free is called. Data is freed
 	 * by devcoredump framework automatically after 5 minutes.
 	 */
 	wait_for_completion(&dump_state.dump_done);
 }
 EXPORT_SYMBOL(rproc_coredump_using_sections);
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Coredump functionality for Remoteproc framework.
	*
	* Copyright (c) 2020, The Linux Foundation. All rights reserved.
	*/

	#include <linux/completion.h>
	#include <linux/devcoredump.h>
	#include <linux/device.h>
	#include <linux/kernel.h>
	#include <linux/remoteproc.h>
	#include "remoteproc_internal.h"
	#include "remoteproc_elf_helpers.h"

	struct rproc_coredump_state {
	struct rproc *rproc;
	void *header;
	struct completion dump_done;
	};

	/**
	* rproc_coredump_cleanup() - clean up dump_segments list
	* @rproc: the remote processor handle
	*/
	void rproc_coredump_cleanup(struct rproc *rproc)
	{
	struct rproc_dump_segment entry, tmp;

	list_for_each_entry_safe(entry, tmp, &rproc->dump_segments, node) {
	list_del(&entry->node);
	kfree(entry);
	}
	}
	EXPORT_SYMBOL_GPL(rproc_coredump_cleanup);

	/**
	* rproc_coredump_add_segment() - add segment of device memory to coredump
	* @rproc: handle of a remote processor
	* @da: device address
	* @size: size of segment
	*
	* Add device memory to the list of segments to be included in a coredump for
	* the remoteproc.
	*
	* Return: 0 on success, negative errno on error.
	*/
	int rproc_coredump_add_segment(struct rproc *rproc, dma_addr_t da, size_t size)
	{
	struct rproc_dump_segment *segment;

	segment = kzalloc(sizeof(*segment), GFP_KERNEL);
	if (!segment)
	return -ENOMEM;

	segment->da = da;
	segment->size = size;

	list_add_tail(&segment->node, &rproc->dump_segments);

	return 0;
	}
	EXPORT_SYMBOL(rproc_coredump_add_segment);

	/**
	* rproc_coredump_add_custom_segment() - add custom coredump segment
	* @rproc: handle of a remote processor
	* @da: device address
	* @size: size of segment
	* @dumpfn: custom dump function called for each segment during coredump
	* @priv: private data
	*
	* Add device memory to the list of segments to be included in the coredump
	* and associate the segment with the given custom dump function and private
	* data.
	*
	* Return: 0 on success, negative errno on error.
	*/
	int rproc_coredump_add_custom_segment(struct rproc *rproc,
	dma_addr_t da, size_t size,
	void (dumpfn)(struct rproc rproc,
	struct rproc_dump_segment *segment,
	void *dest, size_t offset,
	size_t size),
	void *priv)
	{
	struct rproc_dump_segment *segment;

	segment = kzalloc(sizeof(*segment), GFP_KERNEL);
	if (!segment)
	return -ENOMEM;

	segment->da = da;
	segment->size = size;
	segment->priv = priv;
	segment->dump = dumpfn;

	list_add_tail(&segment->node, &rproc->dump_segments);

	return 0;
	}
	EXPORT_SYMBOL(rproc_coredump_add_custom_segment);

	/**
	* rproc_coredump_set_elf_info() - set coredump elf information
	* @rproc: handle of a remote processor
	* @class: elf class for coredump elf file
	* @machine: elf machine for coredump elf file
	*
	* Set elf information which will be used for coredump elf file.
	*
	* Return: 0 on success, negative errno on error.
	*/
	int rproc_coredump_set_elf_info(struct rproc *rproc, u8 class, u16 machine)
	{
	if (class != ELFCLASS64 && class != ELFCLASS32)
	return -EINVAL;

	rproc->elf_class = class;
	rproc->elf_machine = machine;

	return 0;
	}
	EXPORT_SYMBOL(rproc_coredump_set_elf_info);

	static void rproc_coredump_free(void *data)
	{
	struct rproc_coredump_state *dump_state = data;

	vfree(dump_state->header);
	complete(&dump_state->dump_done);
	}

	static void *rproc_coredump_find_segment(loff_t user_offset,
	struct list_head *segments,
	size_t *data_left)
	{
	struct rproc_dump_segment *segment;

	list_for_each_entry(segment, segments, node) {
	if (user_offset < segment->size) {
	*data_left = segment->size - user_offset;
	return segment;
	}
	user_offset -= segment->size;
	}

	*data_left = 0;
	return NULL;
	}

	static void rproc_copy_segment(struct rproc rproc, void dest,
	struct rproc_dump_segment *segment,
	size_t offset, size_t size)
	{
	bool is_iomem = false;
	void *ptr;

	if (segment->dump) {
	segment->dump(rproc, segment, dest, offset, size);
	} else {
	ptr = rproc_da_to_va(rproc, segment->da + offset, size, &is_iomem);
	if (!ptr) {
	dev_err(&rproc->dev,
	"invalid copy request for segment %pad with offset %zu and size %zu)\n",
	&segment->da, offset, size);
	memset(dest, 0xff, size);
	} else {
	if (is_iomem)
	memcpy_fromio(dest, (void const __iomem *)ptr, size);
	else
	memcpy(dest, ptr, size);
	}
	}
	}

	static ssize_t rproc_coredump_read(char *buffer, loff_t offset, size_t count,
	void *data, size_t header_sz)
	{
	size_t seg_data, bytes_left = count;
	ssize_t copy_sz;
	struct rproc_dump_segment *seg;
	struct rproc_coredump_state *dump_state = data;
	struct rproc *rproc = dump_state->rproc;
	void *elfcore = dump_state->header;

	/* Copy the vmalloc'ed header first. */
	if (offset < header_sz) {
	copy_sz = memory_read_from_buffer(buffer, count, &offset,
	elfcore, header_sz);

	return copy_sz;
	}

	/*
	* Find out the segment memory chunk to be copied based on offset.
	* Keep copying data until count bytes are read.
	*/
	while (bytes_left) {
	seg = rproc_coredump_find_segment(offset - header_sz,
	&rproc->dump_segments,
	&seg_data);
	/* EOF check */
	if (!seg) {
	dev_info(&rproc->dev, "Ramdump done, %lld bytes read",
	offset);
	break;
	}

	copy_sz = min_t(size_t, bytes_left, seg_data);

	rproc_copy_segment(rproc, buffer, seg, seg->size - seg_data,
	copy_sz);

	offset += copy_sz;
	buffer += copy_sz;
	bytes_left -= copy_sz;
	}

	return count - bytes_left;
	}

	/**
	* rproc_coredump() - perform coredump
	* @rproc: rproc handle
	*
	* This function will generate an ELF header for the registered segments
	* and create a devcoredump device associated with rproc. Based on the
	* coredump configuration this function will directly copy the segments
	* from device memory to userspace or copy segments from device memory to
	* a separate buffer, which can then be read by userspace.
	* The first approach avoids using extra vmalloc memory. But it will stall
	* recovery flow until dump is read by userspace.
	*/
	void rproc_coredump(struct rproc *rproc)
	{
	struct rproc_dump_segment *segment;
	void *phdr;
	void *ehdr;
	size_t data_size;
	size_t offset;
	void *data;
	u8 class = rproc->elf_class;
	int phnum = 0;
	struct rproc_coredump_state dump_state;
	enum rproc_dump_mechanism dump_conf = rproc->dump_conf;

	if (list_empty(&rproc->dump_segments) \|\|
	dump_conf == RPROC_COREDUMP_DISABLED)
	return;

	if (class == ELFCLASSNONE) {
	dev_err(&rproc->dev, "ELF class is not set\n");
	return;
	}

	data_size = elf_size_of_hdr(class);
	list_for_each_entry(segment, &rproc->dump_segments, node) {
	/*
	* For default configuration buffer includes headers & segments.
	* For inline dump buffer just includes headers as segments are
	* directly read from device memory.
	*/
	data_size += elf_size_of_phdr(class);
	if (dump_conf == RPROC_COREDUMP_ENABLED)
	data_size += segment->size;

	phnum++;
	}

	data = vmalloc(data_size);
	if (!data)
	return;

	ehdr = data;

	memset(ehdr, 0, elf_size_of_hdr(class));
	/* e_ident field is common for both elf32 and elf64 */
	elf_hdr_init_ident(ehdr, class);

	elf_hdr_set_e_type(class, ehdr, ET_CORE);
	elf_hdr_set_e_machine(class, ehdr, rproc->elf_machine);
	elf_hdr_set_e_version(class, ehdr, EV_CURRENT);
	elf_hdr_set_e_entry(class, ehdr, rproc->bootaddr);
	elf_hdr_set_e_phoff(class, ehdr, elf_size_of_hdr(class));
	elf_hdr_set_e_ehsize(class, ehdr, elf_size_of_hdr(class));
	elf_hdr_set_e_phentsize(class, ehdr, elf_size_of_phdr(class));
	elf_hdr_set_e_phnum(class, ehdr, phnum);

	phdr = data + elf_hdr_get_e_phoff(class, ehdr);
	offset = elf_hdr_get_e_phoff(class, ehdr);
	offset += elf_size_of_phdr(class) * elf_hdr_get_e_phnum(class, ehdr);

	list_for_each_entry(segment, &rproc->dump_segments, node) {
	memset(phdr, 0, elf_size_of_phdr(class));
	elf_phdr_set_p_type(class, phdr, PT_LOAD);
	elf_phdr_set_p_offset(class, phdr, offset);
	elf_phdr_set_p_vaddr(class, phdr, segment->da);
	elf_phdr_set_p_paddr(class, phdr, segment->da);
	elf_phdr_set_p_filesz(class, phdr, segment->size);
	elf_phdr_set_p_memsz(class, phdr, segment->size);
	elf_phdr_set_p_flags(class, phdr, PF_R \| PF_W \| PF_X);
	elf_phdr_set_p_align(class, phdr, 0);

	if (dump_conf == RPROC_COREDUMP_ENABLED)
	rproc_copy_segment(rproc, data + offset, segment, 0,
	segment->size);

	offset += elf_phdr_get_p_filesz(class, phdr);
	phdr += elf_size_of_phdr(class);
	}
	if (dump_conf == RPROC_COREDUMP_ENABLED) {
	dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL);
	return;
	}

	/* Initialize the dump state struct to be used by rproc_coredump_read */
	dump_state.rproc = rproc;
	dump_state.header = data;
	init_completion(&dump_state.dump_done);

	dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL,
	rproc_coredump_read, rproc_coredump_free);

	/*
	* Wait until the dump is read and free is called. Data is freed
	* by devcoredump framework automatically after 5 minutes.
	*/
	wait_for_completion(&dump_state.dump_done);
	}
	EXPORT_SYMBOL_GPL(rproc_coredump);

	/**
	* rproc_coredump_using_sections() - perform coredump using section headers
	* @rproc: rproc handle
	*
	* This function will generate an ELF header for the registered sections of
	* segments and create a devcoredump device associated with rproc. Based on
	* the coredump configuration this function will directly copy the segments
	* from device memory to userspace or copy segments from device memory to
	* a separate buffer, which can then be read by userspace.
	* The first approach avoids using extra vmalloc memory. But it will stall
	* recovery flow until dump is read by userspace.
	*/
	void rproc_coredump_using_sections(struct rproc *rproc)
	{
	struct rproc_dump_segment *segment;
	void *shdr;
	void *ehdr;
	size_t data_size;
	size_t strtbl_size = 0;
	size_t strtbl_index = 1;
	size_t offset;
	void *data;
	u8 class = rproc->elf_class;
	int shnum;
	struct rproc_coredump_state dump_state;
	unsigned int dump_conf = rproc->dump_conf;
	char *str_tbl = "STR_TBL";

	if (list_empty(&rproc->dump_segments) \|\|
	dump_conf == RPROC_COREDUMP_DISABLED)
	return;

	if (class == ELFCLASSNONE) {
	dev_err(&rproc->dev, "ELF class is not set\n");
	return;
	}

	/*
	* We allocate two extra section headers. The first one is null.
	* Second section header is for the string table. Also space is
	* allocated for string table.
	*/
	data_size = elf_size_of_hdr(class) + 2 * elf_size_of_shdr(class);
	shnum = 2;

	/* the extra byte is for the null character at index 0 */
	strtbl_size += strlen(str_tbl) + 2;

	list_for_each_entry(segment, &rproc->dump_segments, node) {
	data_size += elf_size_of_shdr(class);
	strtbl_size += strlen(segment->priv) + 1;
	if (dump_conf == RPROC_COREDUMP_ENABLED)
	data_size += segment->size;
	shnum++;
	}

	data_size += strtbl_size;

	data = vmalloc(data_size);
	if (!data)
	return;

	ehdr = data;
	memset(ehdr, 0, elf_size_of_hdr(class));
	/* e_ident field is common for both elf32 and elf64 */
	elf_hdr_init_ident(ehdr, class);

	elf_hdr_set_e_type(class, ehdr, ET_CORE);
	elf_hdr_set_e_machine(class, ehdr, rproc->elf_machine);
	elf_hdr_set_e_version(class, ehdr, EV_CURRENT);
	elf_hdr_set_e_entry(class, ehdr, rproc->bootaddr);
	elf_hdr_set_e_shoff(class, ehdr, elf_size_of_hdr(class));
	elf_hdr_set_e_ehsize(class, ehdr, elf_size_of_hdr(class));
	elf_hdr_set_e_shentsize(class, ehdr, elf_size_of_shdr(class));
	elf_hdr_set_e_shnum(class, ehdr, shnum);
	elf_hdr_set_e_shstrndx(class, ehdr, 1);

	/*
	* The zeroth index of the section header is reserved and is rarely used.
	* Set the section header as null (SHN_UNDEF) and move to the next one.
	*/
	shdr = data + elf_hdr_get_e_shoff(class, ehdr);
	memset(shdr, 0, elf_size_of_shdr(class));
	shdr += elf_size_of_shdr(class);

	/* Initialize the string table. */
	offset = elf_hdr_get_e_shoff(class, ehdr) +
	elf_size_of_shdr(class) * elf_hdr_get_e_shnum(class, ehdr);
	memset(data + offset, 0, strtbl_size);

	/* Fill in the string table section header. */
	memset(shdr, 0, elf_size_of_shdr(class));
	elf_shdr_set_sh_type(class, shdr, SHT_STRTAB);
	elf_shdr_set_sh_offset(class, shdr, offset);
	elf_shdr_set_sh_size(class, shdr, strtbl_size);
	elf_shdr_set_sh_entsize(class, shdr, 0);
	elf_shdr_set_sh_flags(class, shdr, 0);
	elf_shdr_set_sh_name(class, shdr, elf_strtbl_add(str_tbl, ehdr, class, &strtbl_index));
	offset += elf_shdr_get_sh_size(class, shdr);
	shdr += elf_size_of_shdr(class);

	list_for_each_entry(segment, &rproc->dump_segments, node) {
	memset(shdr, 0, elf_size_of_shdr(class));
	elf_shdr_set_sh_type(class, shdr, SHT_PROGBITS);
	elf_shdr_set_sh_offset(class, shdr, offset);
	elf_shdr_set_sh_addr(class, shdr, segment->da);
	elf_shdr_set_sh_size(class, shdr, segment->size);
	elf_shdr_set_sh_entsize(class, shdr, 0);
	elf_shdr_set_sh_flags(class, shdr, SHF_WRITE);
	elf_shdr_set_sh_name(class, shdr,
	elf_strtbl_add(segment->priv, ehdr, class, &strtbl_index));

	/* No need to copy segments for inline dumps */
	if (dump_conf == RPROC_COREDUMP_ENABLED)
	rproc_copy_segment(rproc, data + offset, segment, 0,
	segment->size);
	offset += elf_shdr_get_sh_size(class, shdr);
	shdr += elf_size_of_shdr(class);
	}

	if (dump_conf == RPROC_COREDUMP_ENABLED) {
	dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL);
	return;
	}

	/* Initialize the dump state struct to be used by rproc_coredump_read */
	dump_state.rproc = rproc;
	dump_state.header = data;
	init_completion(&dump_state.dump_done);

	dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL,
	rproc_coredump_read, rproc_coredump_free);

	/* Wait until the dump is read and free is called. Data is freed
	* by devcoredump framework automatically after 5 minutes.
	*/
	wait_for_completion(&dump_state.dump_done);
	}
	EXPORT_SYMBOL(rproc_coredump_using_sections);