arch/powerpc/kernel/machine_kexec_file_64.c - third_party/linux - Git at Google

 /*
  * ppc64 code to implement the kexec_file_load syscall
  *
  * Copyright (C) 2004  Adam Litke (agl@us.ibm.com)
  * Copyright (C) 2004  IBM Corp.
  * Copyright (C) 2004,2005  Milton D Miller II, IBM Corporation
  * Copyright (C) 2005  R Sharada (sharada@in.ibm.com)
  * Copyright (C) 2006  Mohan Kumar M (mohan@in.ibm.com)
  * Copyright (C) 2016  IBM Corporation
  *
  * Based on kexec-tools' kexec-elf-ppc64.c, fs2dt.c.
  * Heavily modified for the kernel by
  * Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation (version 2 of the License).
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #include <linux/slab.h>
 #include <linux/kexec.h>
 #include <linux/memblock.h>
 #include <linux/of_fdt.h>
 #include <linux/libfdt.h>
 #include <asm/ima.h>

 #define SLAVE_CODE_SIZE		256

 const struct kexec_file_ops * const kexec_file_loaders[] = {
 	&kexec_elf64_ops,
 	NULL
 };

 int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
 				  unsigned long buf_len)
 {
 	/* We don't support crash kernels yet. */
 	if (image->type == KEXEC_TYPE_CRASH)
 		return -EOPNOTSUPP;

 	return kexec_image_probe_default(image, buf, buf_len);
 }

 /**
  * arch_kexec_walk_mem - call func(data) for each unreserved memory block
  * @kbuf:	Context info for the search. Also passed to @func.
  * @func:	Function to call for each memory block.
  *
  * This function is used by kexec_add_buffer and kexec_locate_mem_hole
  * to find unreserved memory to load kexec segments into.
  *
  * Return: The memory walk will stop when func returns a non-zero value
  * and that value will be returned. If all free regions are visited without
  * func returning non-zero, then zero will be returned.
  */
 int arch_kexec_walk_mem(struct kexec_buf *kbuf,
 			int (*func)(struct resource *, void *))
 {
 	int ret = 0;
 	u64 i;
 	phys_addr_t mstart, mend;
 	struct resource res = { };

 	if (kbuf->top_down) {
 		for_each_free_mem_range_reverse(i, NUMA_NO_NODE, 0,
 						&mstart, &mend, NULL) {
 			/*
 			 * In memblock, end points to the first byte after the
 			 * range while in kexec, end points to the last byte
 			 * in the range.
 			 */
 			res.start = mstart;
 			res.end = mend - 1;
 			ret = func(&res, kbuf);
 			if (ret)
 				break;
 		}
 	} else {
 		for_each_free_mem_range(i, NUMA_NO_NODE, 0, &mstart, &mend,
 					NULL) {
 			/*
 			 * In memblock, end points to the first byte after the
 			 * range while in kexec, end points to the last byte
 			 * in the range.
 			 */
 			res.start = mstart;
 			res.end = mend - 1;
 			ret = func(&res, kbuf);
 			if (ret)
 				break;
 		}
 	}

 	return ret;
 }

 /**
  * setup_purgatory - initialize the purgatory's global variables
  * @image:		kexec image.
  * @slave_code:		Slave code for the purgatory.
  * @fdt:		Flattened device tree for the next kernel.
  * @kernel_load_addr:	Address where the kernel is loaded.
  * @fdt_load_addr:	Address where the flattened device tree is loaded.
  *
  * Return: 0 on success, or negative errno on error.
  */
 int setup_purgatory(struct kimage *image, const void *slave_code,
 		    const void *fdt, unsigned long kernel_load_addr,
 		    unsigned long fdt_load_addr)
 {
 	unsigned int *slave_code_buf, master_entry;
 	int ret;

 	slave_code_buf = kmalloc(SLAVE_CODE_SIZE, GFP_KERNEL);
 	if (!slave_code_buf)
 		return -ENOMEM;

 	/* Get the slave code from the new kernel and put it in purgatory. */
 	ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
 					     slave_code_buf, SLAVE_CODE_SIZE,
 					     true);
 	if (ret) {
 		kfree(slave_code_buf);
 		return ret;
 	}

 	master_entry = slave_code_buf[0];
 	memcpy(slave_code_buf, slave_code, SLAVE_CODE_SIZE);
 	slave_code_buf[0] = master_entry;
 	ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
 					     slave_code_buf, SLAVE_CODE_SIZE,
 					     false);
 	kfree(slave_code_buf);

 	ret = kexec_purgatory_get_set_symbol(image, "kernel", &kernel_load_addr,
 					     sizeof(kernel_load_addr), false);
 	if (ret)
 		return ret;
 	ret = kexec_purgatory_get_set_symbol(image, "dt_offset", &fdt_load_addr,
 					     sizeof(fdt_load_addr), false);
 	if (ret)
 		return ret;

 	return 0;
 }

 /**
  * delete_fdt_mem_rsv - delete memory reservation with given address and size
  *
  * Return: 0 on success, or negative errno on error.
  */
 int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size)
 {
 	int i, ret, num_rsvs = fdt_num_mem_rsv(fdt);

 	for (i = 0; i < num_rsvs; i++) {
 		uint64_t rsv_start, rsv_size;

 		ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
 		if (ret) {
 			pr_err("Malformed device tree.\n");
 			return -EINVAL;
 		}

 		if (rsv_start == start && rsv_size == size) {
 			ret = fdt_del_mem_rsv(fdt, i);
 			if (ret) {
 				pr_err("Error deleting device tree reservation.\n");
 				return -EINVAL;
 			}

 			return 0;
 		}
 	}

 	return -ENOENT;
 }

 /*
  * setup_new_fdt - modify /chosen and memory reservation for the next kernel
  * @image:		kexec image being loaded.
  * @fdt:		Flattened device tree for the next kernel.
  * @initrd_load_addr:	Address where the next initrd will be loaded.
  * @initrd_len:		Size of the next initrd, or 0 if there will be none.
  * @cmdline:		Command line for the next kernel, or NULL if there will
  *			be none.
  *
  * Return: 0 on success, or negative errno on error.
  */
 int setup_new_fdt(const struct kimage *image, void *fdt,
 		  unsigned long initrd_load_addr, unsigned long initrd_len,
 		  const char *cmdline)
 {
 	int ret, chosen_node;
 	const void *prop;

 	/* Remove memory reservation for the current device tree. */
 	ret = delete_fdt_mem_rsv(fdt, __pa(initial_boot_params),
 				 fdt_totalsize(initial_boot_params));
 	if (ret == 0)
 		pr_debug("Removed old device tree reservation.\n");
 	else if (ret != -ENOENT)
 		return ret;

 	chosen_node = fdt_path_offset(fdt, "/chosen");
 	if (chosen_node == -FDT_ERR_NOTFOUND) {
 		chosen_node = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"),
 					      "chosen");
 		if (chosen_node < 0) {
 			pr_err("Error creating /chosen.\n");
 			return -EINVAL;
 		}
 	} else if (chosen_node < 0) {
 		pr_err("Malformed device tree: error reading /chosen.\n");
 		return -EINVAL;
 	}

 	/* Did we boot using an initrd? */
 	prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", NULL);
 	if (prop) {
 		uint64_t tmp_start, tmp_end, tmp_size;

 		tmp_start = fdt64_to_cpu(*((const fdt64_t *) prop));

 		prop = fdt_getprop(fdt, chosen_node, "linux,initrd-end", NULL);
 		if (!prop) {
 			pr_err("Malformed device tree.\n");
 			return -EINVAL;
 		}
 		tmp_end = fdt64_to_cpu(*((const fdt64_t *) prop));

 		/*
 		 * kexec reserves exact initrd size, while firmware may
 		 * reserve a multiple of PAGE_SIZE, so check for both.
 		 */
 		tmp_size = tmp_end - tmp_start;
 		ret = delete_fdt_mem_rsv(fdt, tmp_start, tmp_size);
 		if (ret == -ENOENT)
 			ret = delete_fdt_mem_rsv(fdt, tmp_start,
 						 round_up(tmp_size, PAGE_SIZE));
 		if (ret == 0)
 			pr_debug("Removed old initrd reservation.\n");
 		else if (ret != -ENOENT)
 			return ret;

 		/* If there's no new initrd, delete the old initrd's info. */
 		if (initrd_len == 0) {
 			ret = fdt_delprop(fdt, chosen_node,
 					  "linux,initrd-start");
 			if (ret) {
 				pr_err("Error deleting linux,initrd-start.\n");
 				return -EINVAL;
 			}

 			ret = fdt_delprop(fdt, chosen_node, "linux,initrd-end");
 			if (ret) {
 				pr_err("Error deleting linux,initrd-end.\n");
 				return -EINVAL;
 			}
 		}
 	}

 	if (initrd_len) {
 		ret = fdt_setprop_u64(fdt, chosen_node,
 				      "linux,initrd-start",
 				      initrd_load_addr);
 		if (ret < 0) {
 			pr_err("Error setting up the new device tree.\n");
 			return -EINVAL;
 		}

 		/* initrd-end is the first address after the initrd image. */
 		ret = fdt_setprop_u64(fdt, chosen_node, "linux,initrd-end",
 				      initrd_load_addr + initrd_len);
 		if (ret < 0) {
 			pr_err("Error setting up the new device tree.\n");
 			return -EINVAL;
 		}

 		ret = fdt_add_mem_rsv(fdt, initrd_load_addr, initrd_len);
 		if (ret) {
 			pr_err("Error reserving initrd memory: %s\n",
 			       fdt_strerror(ret));
 			return -EINVAL;
 		}
 	}

 	if (cmdline != NULL) {
 		ret = fdt_setprop_string(fdt, chosen_node, "bootargs", cmdline);
 		if (ret < 0) {
 			pr_err("Error setting up the new device tree.\n");
 			return -EINVAL;
 		}
 	} else {
 		ret = fdt_delprop(fdt, chosen_node, "bootargs");
 		if (ret && ret != -FDT_ERR_NOTFOUND) {
 			pr_err("Error deleting bootargs.\n");
 			return -EINVAL;
 		}
 	}

 	ret = setup_ima_buffer(image, fdt, chosen_node);
 	if (ret) {
 		pr_err("Error setting up the new device tree.\n");
 		return ret;
 	}

 	ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
 	if (ret) {
 		pr_err("Error setting up the new device tree.\n");
 		return -EINVAL;
 	}

 	return 0;
 }
	/*
	* ppc64 code to implement the kexec_file_load syscall
	*
	* Copyright (C) 2004 Adam Litke (agl@us.ibm.com)
	* Copyright (C) 2004 IBM Corp.
	* Copyright (C) 2004,2005 Milton D Miller II, IBM Corporation
	* Copyright (C) 2005 R Sharada (sharada@in.ibm.com)
	* Copyright (C) 2006 Mohan Kumar M (mohan@in.ibm.com)
	* Copyright (C) 2016 IBM Corporation
	*
	* Based on kexec-tools' kexec-elf-ppc64.c, fs2dt.c.
	* Heavily modified for the kernel by
	* Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation (version 2 of the License).
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#include <linux/slab.h>
	#include <linux/kexec.h>
	#include <linux/memblock.h>
	#include <linux/of_fdt.h>
	#include <linux/libfdt.h>
	#include <asm/ima.h>

	#define SLAVE_CODE_SIZE 256

	const struct kexec_file_ops * const kexec_file_loaders[] = {
	&kexec_elf64_ops,
	NULL
	};

	int arch_kexec_kernel_image_probe(struct kimage image, void buf,
	unsigned long buf_len)
	{
	/* We don't support crash kernels yet. */
	if (image->type == KEXEC_TYPE_CRASH)
	return -EOPNOTSUPP;

	return kexec_image_probe_default(image, buf, buf_len);
	}

	/**
	* arch_kexec_walk_mem - call func(data) for each unreserved memory block
	* @kbuf: Context info for the search. Also passed to @func.
	* @func: Function to call for each memory block.
	*
	* This function is used by kexec_add_buffer and kexec_locate_mem_hole
	* to find unreserved memory to load kexec segments into.
	*
	* Return: The memory walk will stop when func returns a non-zero value
	* and that value will be returned. If all free regions are visited without
	* func returning non-zero, then zero will be returned.
	*/
	int arch_kexec_walk_mem(struct kexec_buf *kbuf,
	int (func)(struct resource , void *))
	{
	int ret = 0;
	u64 i;
	phys_addr_t mstart, mend;
	struct resource res = { };

	if (kbuf->top_down) {
	for_each_free_mem_range_reverse(i, NUMA_NO_NODE, 0,
	&mstart, &mend, NULL) {
	/*
	* In memblock, end points to the first byte after the
	* range while in kexec, end points to the last byte
	* in the range.
	*/
	res.start = mstart;
	res.end = mend - 1;
	ret = func(&res, kbuf);
	if (ret)
	break;
	}
	} else {
	for_each_free_mem_range(i, NUMA_NO_NODE, 0, &mstart, &mend,
	NULL) {
	/*
	* In memblock, end points to the first byte after the
	* range while in kexec, end points to the last byte
	* in the range.
	*/
	res.start = mstart;
	res.end = mend - 1;
	ret = func(&res, kbuf);
	if (ret)
	break;
	}
	}

	return ret;
	}

	/**
	* setup_purgatory - initialize the purgatory's global variables
	* @image: kexec image.
	* @slave_code: Slave code for the purgatory.
	* @fdt: Flattened device tree for the next kernel.
	* @kernel_load_addr: Address where the kernel is loaded.
	* @fdt_load_addr: Address where the flattened device tree is loaded.
	*
	* Return: 0 on success, or negative errno on error.
	*/
	int setup_purgatory(struct kimage image, const void slave_code,
	const void *fdt, unsigned long kernel_load_addr,
	unsigned long fdt_load_addr)
	{
	unsigned int *slave_code_buf, master_entry;
	int ret;

	slave_code_buf = kmalloc(SLAVE_CODE_SIZE, GFP_KERNEL);
	if (!slave_code_buf)
	return -ENOMEM;

	/* Get the slave code from the new kernel and put it in purgatory. */
	ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
	slave_code_buf, SLAVE_CODE_SIZE,
	true);
	if (ret) {
	kfree(slave_code_buf);
	return ret;
	}

	master_entry = slave_code_buf[0];
	memcpy(slave_code_buf, slave_code, SLAVE_CODE_SIZE);
	slave_code_buf[0] = master_entry;
	ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
	slave_code_buf, SLAVE_CODE_SIZE,
	false);
	kfree(slave_code_buf);

	ret = kexec_purgatory_get_set_symbol(image, "kernel", &kernel_load_addr,
	sizeof(kernel_load_addr), false);
	if (ret)
	return ret;
	ret = kexec_purgatory_get_set_symbol(image, "dt_offset", &fdt_load_addr,
	sizeof(fdt_load_addr), false);
	if (ret)
	return ret;

	return 0;
	}

	/**
	* delete_fdt_mem_rsv - delete memory reservation with given address and size
	*
	* Return: 0 on success, or negative errno on error.
	*/
	int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size)
	{
	int i, ret, num_rsvs = fdt_num_mem_rsv(fdt);

	for (i = 0; i < num_rsvs; i++) {
	uint64_t rsv_start, rsv_size;

	ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
	if (ret) {
	pr_err("Malformed device tree.\n");
	return -EINVAL;
	}

	if (rsv_start == start && rsv_size == size) {
	ret = fdt_del_mem_rsv(fdt, i);
	if (ret) {
	pr_err("Error deleting device tree reservation.\n");
	return -EINVAL;
	}

	return 0;
	}
	}

	return -ENOENT;
	}

	/*
	* setup_new_fdt - modify /chosen and memory reservation for the next kernel
	* @image: kexec image being loaded.
	* @fdt: Flattened device tree for the next kernel.
	* @initrd_load_addr: Address where the next initrd will be loaded.
	* @initrd_len: Size of the next initrd, or 0 if there will be none.
	* @cmdline: Command line for the next kernel, or NULL if there will
	* be none.
	*
	* Return: 0 on success, or negative errno on error.
	*/
	int setup_new_fdt(const struct kimage image, void fdt,
	unsigned long initrd_load_addr, unsigned long initrd_len,
	const char *cmdline)
	{
	int ret, chosen_node;
	const void *prop;

	/* Remove memory reservation for the current device tree. */
	ret = delete_fdt_mem_rsv(fdt, __pa(initial_boot_params),
	fdt_totalsize(initial_boot_params));
	if (ret == 0)
	pr_debug("Removed old device tree reservation.\n");
	else if (ret != -ENOENT)
	return ret;

	chosen_node = fdt_path_offset(fdt, "/chosen");
	if (chosen_node == -FDT_ERR_NOTFOUND) {
	chosen_node = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"),
	"chosen");
	if (chosen_node < 0) {
	pr_err("Error creating /chosen.\n");
	return -EINVAL;
	}
	} else if (chosen_node < 0) {
	pr_err("Malformed device tree: error reading /chosen.\n");
	return -EINVAL;
	}

	/* Did we boot using an initrd? */
	prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", NULL);
	if (prop) {
	uint64_t tmp_start, tmp_end, tmp_size;

	tmp_start = fdt64_to_cpu(((const fdt64_t ) prop));

	prop = fdt_getprop(fdt, chosen_node, "linux,initrd-end", NULL);
	if (!prop) {
	pr_err("Malformed device tree.\n");
	return -EINVAL;
	}
	tmp_end = fdt64_to_cpu(((const fdt64_t ) prop));

	/*
	* kexec reserves exact initrd size, while firmware may
	* reserve a multiple of PAGE_SIZE, so check for both.
	*/
	tmp_size = tmp_end - tmp_start;
	ret = delete_fdt_mem_rsv(fdt, tmp_start, tmp_size);
	if (ret == -ENOENT)
	ret = delete_fdt_mem_rsv(fdt, tmp_start,
	round_up(tmp_size, PAGE_SIZE));
	if (ret == 0)
	pr_debug("Removed old initrd reservation.\n");
	else if (ret != -ENOENT)
	return ret;

	/* If there's no new initrd, delete the old initrd's info. */
	if (initrd_len == 0) {
	ret = fdt_delprop(fdt, chosen_node,
	"linux,initrd-start");
	if (ret) {
	pr_err("Error deleting linux,initrd-start.\n");
	return -EINVAL;
	}

	ret = fdt_delprop(fdt, chosen_node, "linux,initrd-end");
	if (ret) {
	pr_err("Error deleting linux,initrd-end.\n");
	return -EINVAL;
	}
	}
	}

	if (initrd_len) {
	ret = fdt_setprop_u64(fdt, chosen_node,
	"linux,initrd-start",
	initrd_load_addr);
	if (ret < 0) {
	pr_err("Error setting up the new device tree.\n");
	return -EINVAL;
	}

	/* initrd-end is the first address after the initrd image. */
	ret = fdt_setprop_u64(fdt, chosen_node, "linux,initrd-end",
	initrd_load_addr + initrd_len);
	if (ret < 0) {
	pr_err("Error setting up the new device tree.\n");
	return -EINVAL;
	}

	ret = fdt_add_mem_rsv(fdt, initrd_load_addr, initrd_len);
	if (ret) {
	pr_err("Error reserving initrd memory: %s\n",
	fdt_strerror(ret));
	return -EINVAL;
	}
	}

	if (cmdline != NULL) {
	ret = fdt_setprop_string(fdt, chosen_node, "bootargs", cmdline);
	if (ret < 0) {
	pr_err("Error setting up the new device tree.\n");
	return -EINVAL;
	}
	} else {
	ret = fdt_delprop(fdt, chosen_node, "bootargs");
	if (ret && ret != -FDT_ERR_NOTFOUND) {
	pr_err("Error deleting bootargs.\n");
	return -EINVAL;
	}
	}

	ret = setup_ima_buffer(image, fdt, chosen_node);
	if (ret) {
	pr_err("Error setting up the new device tree.\n");
	return ret;
	}

	ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
	if (ret) {
	pr_err("Error setting up the new device tree.\n");
	return -EINVAL;
	}

	return 0;
	}