// 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 . */ #include #include #include #include #include #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; }