@@ -91,6 +91,18 @@ static inline bool kdump_in_progress(void)
return crashing_cpu >= 0;
}
+#ifdef CONFIG_KEXEC_FILE
+#define PURGATORY_ELF_TYPE ET_EXEC
+
+extern struct kexec_file_ops kexec_elf64_ops;
+
+int setup_purgatory(struct kimage *image, const void *slave_code,
+ const void *fdt, unsigned long kernel_load_addr,
+ unsigned long fdt_load_addr, unsigned long stack_top);
+int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,
+ unsigned long initrd_len, const char *cmdline);
+#endif /* CONFIG_KEXEC_FILE */
+
#else /* !CONFIG_KEXEC_CORE */
static inline void crash_kexec_secondary(struct pt_regs *regs) { }
@@ -109,7 +109,8 @@ obj-$(CONFIG_PCI) += pci_$(BITS).o $(pci64-y) \
obj-$(CONFIG_PCI_MSI) += msi.o
obj-$(CONFIG_KEXEC_CORE) += machine_kexec.o crash.o \
machine_kexec_$(BITS).o
-obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file_$(BITS).o elf_util.o
+obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file_$(BITS).o elf_util.o \
+ kexec_elf_$(BITS).o
obj-$(CONFIG_AUDIT) += audit.o
obj64-$(CONFIG_AUDIT) += compat_audit.o
new file mode 100644
@@ -0,0 +1,279 @@
+/*
+ * Load ELF vmlinux file for the kexec_file_load syscall.
+ *
+ * Copyright (C) 2004 Adam Litke (agl@us.ibm.com)
+ * Copyright (C) 2004 IBM Corp.
+ * 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-exec.c and kexec-elf-ppc64.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.
+ */
+
+#define pr_fmt(fmt) "kexec_elf: " fmt
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/elf.h>
+#include <linux/kexec.h>
+#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
+#include <asm/elf_util.h>
+
+#define PURGATORY_STACK_SIZE (16 * 1024)
+
+/**
+ * build_elf_exec_info - read ELF executable and check that we can use it
+ */
+static int build_elf_exec_info(const char *buf, size_t len, struct elfhdr *ehdr,
+ struct elf_info *elf_info)
+{
+ int i;
+ int ret;
+
+ ret = elf_read_from_buffer(buf, len, ehdr, elf_info);
+ if (ret)
+ return ret;
+
+ /* Big endian vmlinux has type ET_DYN. */
+ if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) {
+ pr_err("Not an ELF executable.\n");
+ goto error;
+ } else if (!elf_info->proghdrs) {
+ pr_err("No ELF program header.\n");
+ goto error;
+ }
+
+ for (i = 0; i < ehdr->e_phnum; i++) {
+ /*
+ * Kexec does not support loading interpreters.
+ * In addition this check keeps us from attempting
+ * to kexec ordinay executables.
+ */
+ if (elf_info->proghdrs[i].p_type == PT_INTERP) {
+ pr_err("Requires an ELF interpreter.\n");
+ goto error;
+ }
+ }
+
+ return 0;
+error:
+ elf_free_info(elf_info);
+ return -ENOEXEC;
+}
+
+static int elf64_probe(const char *buf, unsigned long len)
+{
+ struct elfhdr ehdr;
+ struct elf_info elf_info;
+ int ret;
+
+ ret = build_elf_exec_info(buf, len, &ehdr, &elf_info);
+ if (ret)
+ return ret;
+
+ elf_free_info(&elf_info);
+
+ return elf_check_arch(&ehdr) ? 0 : -ENOEXEC;
+}
+
+/**
+ * elf_exec_load - load ELF executable image
+ * @lowest_load_addr: On return, will be the address where the first PT_LOAD
+ * section will be loaded in memory.
+ *
+ * Return:
+ * 0 on success, negative value on failure.
+ */
+static int elf_exec_load(struct kimage *image, struct elfhdr *ehdr,
+ struct elf_info *elf_info,
+ unsigned long *lowest_load_addr)
+{
+ unsigned long base = 0, lowest_addr = UINT_MAX;
+ int ret;
+ size_t i;
+ struct kexec_buf kbuf = { .image = image, .buf_max = ppc64_rma_size,
+ .top_down = false };
+
+ /* Read in the PT_LOAD segments. */
+ for (i = 0; i < ehdr->e_phnum; i++) {
+ unsigned long load_addr;
+ size_t size;
+ const struct elf_phdr *phdr;
+
+ phdr = &elf_info->proghdrs[i];
+ if (phdr->p_type != PT_LOAD)
+ continue;
+
+ size = phdr->p_filesz;
+ if (size > phdr->p_memsz)
+ size = phdr->p_memsz;
+
+ kbuf.buffer = (void *) elf_info->buffer + phdr->p_offset;
+ kbuf.bufsz = size;
+ kbuf.memsz = phdr->p_memsz;
+ kbuf.buf_align = phdr->p_align;
+ kbuf.buf_min = phdr->p_paddr + base;
+ ret = kexec_add_buffer(&kbuf);
+ if (ret)
+ goto out;
+ load_addr = kbuf.mem;
+
+ if (load_addr < lowest_addr)
+ lowest_addr = load_addr;
+ }
+
+ /* Update entry point to reflect new load address. */
+ ehdr->e_entry += base;
+
+ *lowest_load_addr = lowest_addr;
+ ret = 0;
+ out:
+ return ret;
+}
+
+static void *elf64_load(struct kimage *image, char *kernel_buf,
+ unsigned long kernel_len, char *initrd,
+ unsigned long initrd_len, char *cmdline,
+ unsigned long cmdline_len)
+{
+ int i, ret;
+ unsigned int fdt_size;
+ unsigned long kernel_load_addr, purgatory_load_addr;
+ unsigned long initrd_load_addr = 0, fdt_load_addr, stack_top;
+ void *fdt;
+ const void *slave_code;
+ struct elfhdr ehdr;
+ struct elf_info elf_info;
+ struct fdt_reserve_entry *rsvmap;
+ struct kexec_buf kbuf = { .image = image, .buf_min = 0,
+ .buf_max = ppc64_rma_size };
+
+ ret = build_elf_exec_info(kernel_buf, kernel_len, &ehdr, &elf_info);
+ if (ret)
+ goto out;
+
+ ret = elf_exec_load(image, &ehdr, &elf_info, &kernel_load_addr);
+ if (ret)
+ goto out;
+
+ pr_debug("Loaded the kernel at 0x%lx\n", kernel_load_addr);
+
+ ret = kexec_load_purgatory(image, 0, ppc64_rma_size, true,
+ &purgatory_load_addr);
+ if (ret) {
+ pr_err("Loading purgatory failed.\n");
+ goto out;
+ }
+
+ pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr);
+
+ if (initrd != NULL) {
+ kbuf.buffer = initrd;
+ kbuf.bufsz = kbuf.memsz = initrd_len;
+ kbuf.buf_align = PAGE_SIZE;
+ kbuf.top_down = false;
+ ret = kexec_add_buffer(&kbuf);
+ if (ret)
+ goto out;
+ initrd_load_addr = kbuf.mem;
+
+ pr_debug("Loaded initrd at 0x%lx\n", initrd_load_addr);
+ }
+
+ fdt_size = fdt_totalsize(initial_boot_params) * 2;
+ fdt = kmalloc(fdt_size, GFP_KERNEL);
+ if (!fdt) {
+ pr_err("Not enough memory for the device tree.\n");
+ ret = -ENOMEM;
+ goto out;
+ }
+ ret = fdt_open_into(initial_boot_params, fdt, fdt_size);
+ if (ret < 0) {
+ pr_err("Error setting up the new device tree.\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = setup_new_fdt(fdt, initrd_load_addr, initrd_len, cmdline);
+ if (ret)
+ goto out;
+
+ /*
+ * Documentation/devicetree/booting-without-of.txt says we need to
+ * add a reservation entry for the device tree block, but
+ * early_init_fdt_reserve_self reserves the memory even if there's no
+ * such entry. We'll add a reservation entry anyway, to be safe and
+ * compliant.
+ *
+ * Use dummy values, we will correct them in a moment.
+ */
+ ret = fdt_add_mem_rsv(fdt, 1, 1);
+ if (ret) {
+ pr_err("Error reserving device tree memory: %s\n",
+ fdt_strerror(ret));
+ ret = -EINVAL;
+ goto out;
+ }
+ fdt_pack(fdt);
+
+ kbuf.buffer = fdt;
+ kbuf.bufsz = kbuf.memsz = fdt_size;
+ kbuf.buf_align = PAGE_SIZE;
+ kbuf.top_down = true;
+ ret = kexec_add_buffer(&kbuf);
+ if (ret)
+ goto out;
+ fdt_load_addr = kbuf.mem;
+
+ /*
+ * Fix fdt reservation, now that we now where it will be loaded
+ * and how big it is.
+ */
+ rsvmap = fdt + fdt_off_mem_rsvmap(fdt);
+ i = fdt_num_mem_rsv(fdt) - 1;
+ rsvmap[i].address = cpu_to_fdt64(fdt_load_addr);
+ rsvmap[i].size = cpu_to_fdt64(fdt_totalsize(fdt));
+
+ pr_debug("Loaded device tree at 0x%lx\n", fdt_load_addr);
+
+ kbuf.memsz = PURGATORY_STACK_SIZE;
+ kbuf.buf_align = PAGE_SIZE;
+ kbuf.top_down = true;
+ ret = kexec_locate_mem_hole(&kbuf);
+ if (ret) {
+ pr_err("Couldn't find free memory for the purgatory stack.\n");
+ ret = -ENOMEM;
+ goto out;
+ }
+ stack_top = kbuf.mem + PURGATORY_STACK_SIZE - 1;
+ pr_debug("Purgatory stack is at 0x%lx\n", stack_top);
+
+ slave_code = elf_info.buffer + elf_info.proghdrs[0].p_offset;
+ ret = setup_purgatory(image, slave_code, fdt, kernel_load_addr,
+ fdt_load_addr, stack_top);
+ if (ret)
+ pr_err("Error setting up the purgatory.\n");
+
+out:
+ elf_free_info(&elf_info);
+
+ /* Make kimage_file_post_load_cleanup free the fdt buffer for us. */
+ return ret ? ERR_PTR(ret) : fdt;
+}
+
+struct kexec_file_ops kexec_elf64_ops = {
+ .probe = elf64_probe,
+ .load = elf64_load,
+};
@@ -3,11 +3,12 @@
*
* 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.
+ * Based on kexec-tools' kexec-elf-ppc64.c, fs2dt.c.
* Heavily modified for the kernel by
* Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>.
*
@@ -24,11 +25,15 @@
#include <linux/slab.h>
#include <linux/kexec.h>
#include <linux/memblock.h>
+#include <linux/of_fdt.h>
#include <linux/libfdt.h>
+#include <asm/elf_util.h>
#define SLAVE_CODE_SIZE 256
-static struct kexec_file_ops *kexec_file_loaders[] = { };
+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)
@@ -299,3 +304,275 @@ int arch_kexec_apply_relocations_add(const Elf64_Ehdr *ehdr,
return 0;
}
+
+/**
+ * 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.
+ * @stack_top: Address where the purgatory can place its stack.
+ *
+ * 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 long stack_top)
+{
+ int i, ret, tree_node;
+ const void *prop;
+ unsigned long opal_base, opal_entry, toc;
+ unsigned int *slave_code_buf, master_entry;
+ const struct purgatory_info *pi = &image->purgatory_info;
+ const Elf_Shdr *sechdrs = pi->sechdrs;
+ const char *shstrtab;
+
+ 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;
+
+ tree_node = fdt_path_offset(fdt, "/ibm,opal");
+ if (tree_node >= 0) {
+ prop = fdt_getprop(fdt, tree_node, "opal-base-address", NULL);
+ if (!prop) {
+ pr_err("OPAL address not found in the device tree.\n");
+ return -EINVAL;
+ }
+ opal_base = fdt64_to_cpu((const fdt64_t *) prop);
+
+ prop = fdt_getprop(fdt, tree_node, "opal-entry-address", NULL);
+ if (!prop) {
+ pr_err("OPAL address not found in the device tree.\n");
+ return -EINVAL;
+ }
+ opal_entry = fdt64_to_cpu((const fdt64_t *) prop);
+
+ ret = kexec_purgatory_get_set_symbol(image, "opal_base",
+ &opal_base,
+ sizeof(opal_base), false);
+ if (ret)
+ return ret;
+ ret = kexec_purgatory_get_set_symbol(image, "opal_entry",
+ &opal_entry,
+ sizeof(opal_entry), false);
+ if (ret)
+ return ret;
+ }
+
+ ret = kexec_purgatory_get_set_symbol(image, "stack", &stack_top,
+ sizeof(stack_top), false);
+ if (ret)
+ return ret;
+
+ /* Section header string table. */
+ shstrtab = (const char *) sechdrs[pi->ehdr->e_shstrndx].sh_offset;
+
+ /* Find the TOC address by looking for the .got section. */
+ for (i = 0; i < pi->ehdr->e_shnum; i++)
+ if (!strcmp(&shstrtab[sechdrs[i].sh_name], ".got")) {
+ toc = sechdrs[i].sh_addr + 0x8000;
+
+ break;
+ }
+
+ if (i == pi->ehdr->e_shnum)
+ return -EINVAL;
+
+ ret = kexec_purgatory_get_set_symbol(image, "my_toc", &toc, sizeof(toc),
+ false);
+ if (ret)
+ return ret;
+
+ pr_debug("Purgatory TOC is at 0x%lx\n", toc);
+
+ return 0;
+}
+
+/**
+ * delete_fdt_mem_rsv - delete memory reservation with given address and size
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static 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
+ * @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(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 = 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;
+}