mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-03 17:40:04 +00:00
![Thiago Jung Bauermann](/assets/img/avatar_default.png)
The IMA kexec buffer allows the currently running kernel to pass the measurement list via a kexec segment to the kernel that will be kexec'd. This is the architecture-specific part of setting up the IMA kexec buffer for the next kernel. It will be used in the next patch. Link: http://lkml.kernel.org/r/1480554346-29071-6-git-send-email-zohar@linux.vnet.ibm.com Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andreas Steffen <andreas.steffen@strongswan.org> Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Cc: Josh Sklar <sklar@linux.vnet.ibm.com> Cc: Dave Young <dyoung@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
347 lines
9.3 KiB
C
347 lines
9.3 KiB
C
/*
|
|
* 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
|
|
|
|
static struct kexec_file_ops *kexec_file_loaders[] = {
|
|
&kexec_elf64_ops,
|
|
};
|
|
|
|
int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
|
|
unsigned long buf_len)
|
|
{
|
|
int i, ret = -ENOEXEC;
|
|
struct kexec_file_ops *fops;
|
|
|
|
/* We don't support crash kernels yet. */
|
|
if (image->type == KEXEC_TYPE_CRASH)
|
|
return -ENOTSUPP;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) {
|
|
fops = kexec_file_loaders[i];
|
|
if (!fops || !fops->probe)
|
|
continue;
|
|
|
|
ret = fops->probe(buf, buf_len);
|
|
if (!ret) {
|
|
image->fops = fops;
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
void *arch_kexec_kernel_image_load(struct kimage *image)
|
|
{
|
|
if (!image->fops || !image->fops->load)
|
|
return ERR_PTR(-ENOEXEC);
|
|
|
|
return image->fops->load(image, image->kernel_buf,
|
|
image->kernel_buf_len, image->initrd_buf,
|
|
image->initrd_buf_len, image->cmdline_buf,
|
|
image->cmdline_buf_len);
|
|
}
|
|
|
|
int arch_kimage_file_post_load_cleanup(struct kimage *image)
|
|
{
|
|
if (!image->fops || !image->fops->cleanup)
|
|
return 0;
|
|
|
|
return image->fops->cleanup(image->image_loader_data);
|
|
}
|
|
|
|
/**
|
|
* 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)(u64, u64, void *))
|
|
{
|
|
int ret = 0;
|
|
u64 i;
|
|
phys_addr_t mstart, mend;
|
|
|
|
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.
|
|
*/
|
|
ret = func(mstart, mend - 1, 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.
|
|
*/
|
|
ret = func(mstart, mend - 1, 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;
|
|
}
|