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// SPDX-License-Identifier: GPL-2.0-only
/*
* 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>.
*/
#include <linux/slab.h>
#include <linux/kexec.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);
}
/**
* 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)
goto err;
/* 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)
goto err;
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)
goto err;
} 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)
goto err;
return 0;
err:
pr_err("Error setting up the new device tree.\n");
return -EINVAL;
}
|
