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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /arch/arm64/kernel/machine_kexec_file.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/kernel/machine_kexec_file.c')
-rw-r--r-- | arch/arm64/kernel/machine_kexec_file.c | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c new file mode 100644 index 000000000..0cde47a63 --- /dev/null +++ b/arch/arm64/kernel/machine_kexec_file.c @@ -0,0 +1,348 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * kexec_file for arm64 + * + * Copyright (C) 2018 Linaro Limited + * Author: AKASHI Takahiro <takahiro.akashi@linaro.org> + * + * Most code is derived from arm64 port of kexec-tools + */ + +#define pr_fmt(fmt) "kexec_file: " fmt + +#include <linux/ioport.h> +#include <linux/kernel.h> +#include <linux/kexec.h> +#include <linux/libfdt.h> +#include <linux/memblock.h> +#include <linux/of_fdt.h> +#include <linux/random.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/vmalloc.h> +#include <asm/byteorder.h> + +/* relevant device tree properties */ +#define FDT_PROP_KEXEC_ELFHDR "linux,elfcorehdr" +#define FDT_PROP_MEM_RANGE "linux,usable-memory-range" +#define FDT_PROP_INITRD_START "linux,initrd-start" +#define FDT_PROP_INITRD_END "linux,initrd-end" +#define FDT_PROP_BOOTARGS "bootargs" +#define FDT_PROP_KASLR_SEED "kaslr-seed" +#define FDT_PROP_RNG_SEED "rng-seed" +#define RNG_SEED_SIZE 128 + +const struct kexec_file_ops * const kexec_file_loaders[] = { + &kexec_image_ops, + NULL +}; + +int arch_kimage_file_post_load_cleanup(struct kimage *image) +{ + vfree(image->arch.dtb); + image->arch.dtb = NULL; + + vfree(image->arch.elf_headers); + image->arch.elf_headers = NULL; + image->arch.elf_headers_sz = 0; + + return kexec_image_post_load_cleanup_default(image); +} + +static int setup_dtb(struct kimage *image, + unsigned long initrd_load_addr, unsigned long initrd_len, + char *cmdline, void *dtb) +{ + int off, ret; + + ret = fdt_path_offset(dtb, "/chosen"); + if (ret < 0) + goto out; + + off = ret; + + ret = fdt_delprop(dtb, off, FDT_PROP_KEXEC_ELFHDR); + if (ret && ret != -FDT_ERR_NOTFOUND) + goto out; + ret = fdt_delprop(dtb, off, FDT_PROP_MEM_RANGE); + if (ret && ret != -FDT_ERR_NOTFOUND) + goto out; + + if (image->type == KEXEC_TYPE_CRASH) { + /* add linux,elfcorehdr */ + ret = fdt_appendprop_addrrange(dtb, 0, off, + FDT_PROP_KEXEC_ELFHDR, + image->arch.elf_headers_mem, + image->arch.elf_headers_sz); + if (ret) + return (ret == -FDT_ERR_NOSPACE ? -ENOMEM : -EINVAL); + + /* add linux,usable-memory-range */ + ret = fdt_appendprop_addrrange(dtb, 0, off, + FDT_PROP_MEM_RANGE, + crashk_res.start, + crashk_res.end - crashk_res.start + 1); + if (ret) + return (ret == -FDT_ERR_NOSPACE ? -ENOMEM : -EINVAL); + } + + /* add bootargs */ + if (cmdline) { + ret = fdt_setprop_string(dtb, off, FDT_PROP_BOOTARGS, cmdline); + if (ret) + goto out; + } else { + ret = fdt_delprop(dtb, off, FDT_PROP_BOOTARGS); + if (ret && (ret != -FDT_ERR_NOTFOUND)) + goto out; + } + + /* add initrd-* */ + if (initrd_load_addr) { + ret = fdt_setprop_u64(dtb, off, FDT_PROP_INITRD_START, + initrd_load_addr); + if (ret) + goto out; + + ret = fdt_setprop_u64(dtb, off, FDT_PROP_INITRD_END, + initrd_load_addr + initrd_len); + if (ret) + goto out; + } else { + ret = fdt_delprop(dtb, off, FDT_PROP_INITRD_START); + if (ret && (ret != -FDT_ERR_NOTFOUND)) + goto out; + + ret = fdt_delprop(dtb, off, FDT_PROP_INITRD_END); + if (ret && (ret != -FDT_ERR_NOTFOUND)) + goto out; + } + + /* add kaslr-seed */ + ret = fdt_delprop(dtb, off, FDT_PROP_KASLR_SEED); + if (ret == -FDT_ERR_NOTFOUND) + ret = 0; + else if (ret) + goto out; + + if (rng_is_initialized()) { + u64 seed = get_random_u64(); + ret = fdt_setprop_u64(dtb, off, FDT_PROP_KASLR_SEED, seed); + if (ret) + goto out; + } else { + pr_notice("RNG is not initialised: omitting \"%s\" property\n", + FDT_PROP_KASLR_SEED); + } + + /* add rng-seed */ + if (rng_is_initialized()) { + void *rng_seed; + ret = fdt_setprop_placeholder(dtb, off, FDT_PROP_RNG_SEED, + RNG_SEED_SIZE, &rng_seed); + if (ret) + goto out; + get_random_bytes(rng_seed, RNG_SEED_SIZE); + } else { + pr_notice("RNG is not initialised: omitting \"%s\" property\n", + FDT_PROP_RNG_SEED); + } + +out: + if (ret) + return (ret == -FDT_ERR_NOSPACE) ? -ENOMEM : -EINVAL; + + return 0; +} + +/* + * More space needed so that we can add initrd, bootargs, kaslr-seed, + * rng-seed, userable-memory-range and elfcorehdr. + */ +#define DTB_EXTRA_SPACE 0x1000 + +static int create_dtb(struct kimage *image, + unsigned long initrd_load_addr, unsigned long initrd_len, + char *cmdline, void **dtb) +{ + void *buf; + size_t buf_size; + size_t cmdline_len; + int ret; + + cmdline_len = cmdline ? strlen(cmdline) : 0; + buf_size = fdt_totalsize(initial_boot_params) + + cmdline_len + DTB_EXTRA_SPACE; + + for (;;) { + buf = vmalloc(buf_size); + if (!buf) + return -ENOMEM; + + /* duplicate a device tree blob */ + ret = fdt_open_into(initial_boot_params, buf, buf_size); + if (ret) { + vfree(buf); + return -EINVAL; + } + + ret = setup_dtb(image, initrd_load_addr, initrd_len, + cmdline, buf); + if (ret) { + vfree(buf); + if (ret == -ENOMEM) { + /* unlikely, but just in case */ + buf_size += DTB_EXTRA_SPACE; + continue; + } else { + return ret; + } + } + + /* trim it */ + fdt_pack(buf); + *dtb = buf; + + return 0; + } +} + +static int prepare_elf_headers(void **addr, unsigned long *sz) +{ + struct crash_mem *cmem; + unsigned int nr_ranges; + int ret; + u64 i; + phys_addr_t start, end; + + nr_ranges = 1; /* for exclusion of crashkernel region */ + for_each_mem_range(i, &start, &end) + nr_ranges++; + + cmem = kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL); + if (!cmem) + return -ENOMEM; + + cmem->max_nr_ranges = nr_ranges; + cmem->nr_ranges = 0; + for_each_mem_range(i, &start, &end) { + cmem->ranges[cmem->nr_ranges].start = start; + cmem->ranges[cmem->nr_ranges].end = end - 1; + cmem->nr_ranges++; + } + + /* Exclude crashkernel region */ + ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end); + + if (!ret) + ret = crash_prepare_elf64_headers(cmem, true, addr, sz); + + kfree(cmem); + return ret; +} + +/* + * Tries to add the initrd and DTB to the image. If it is not possible to find + * valid locations, this function will undo changes to the image and return non + * zero. + */ +int load_other_segments(struct kimage *image, + unsigned long kernel_load_addr, + unsigned long kernel_size, + char *initrd, unsigned long initrd_len, + char *cmdline) +{ + struct kexec_buf kbuf; + void *headers, *dtb = NULL; + unsigned long headers_sz, initrd_load_addr = 0, dtb_len, + orig_segments = image->nr_segments; + int ret = 0; + + kbuf.image = image; + /* not allocate anything below the kernel */ + kbuf.buf_min = kernel_load_addr + kernel_size; + + /* load elf core header */ + if (image->type == KEXEC_TYPE_CRASH) { + ret = prepare_elf_headers(&headers, &headers_sz); + if (ret) { + pr_err("Preparing elf core header failed\n"); + goto out_err; + } + + kbuf.buffer = headers; + kbuf.bufsz = headers_sz; + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; + kbuf.memsz = headers_sz; + kbuf.buf_align = SZ_64K; /* largest supported page size */ + kbuf.buf_max = ULONG_MAX; + kbuf.top_down = true; + + ret = kexec_add_buffer(&kbuf); + if (ret) { + vfree(headers); + goto out_err; + } + image->arch.elf_headers = headers; + image->arch.elf_headers_mem = kbuf.mem; + image->arch.elf_headers_sz = headers_sz; + + pr_debug("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n", + image->arch.elf_headers_mem, kbuf.bufsz, kbuf.memsz); + } + + /* load initrd */ + if (initrd) { + kbuf.buffer = initrd; + kbuf.bufsz = initrd_len; + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; + kbuf.memsz = initrd_len; + kbuf.buf_align = 0; + /* within 1GB-aligned window of up to 32GB in size */ + kbuf.buf_max = round_down(kernel_load_addr, SZ_1G) + + (unsigned long)SZ_1G * 32; + kbuf.top_down = false; + + ret = kexec_add_buffer(&kbuf); + if (ret) + goto out_err; + initrd_load_addr = kbuf.mem; + + pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n", + initrd_load_addr, kbuf.bufsz, kbuf.memsz); + } + + /* load dtb */ + ret = create_dtb(image, initrd_load_addr, initrd_len, cmdline, &dtb); + if (ret) { + pr_err("Preparing for new dtb failed\n"); + goto out_err; + } + + dtb_len = fdt_totalsize(dtb); + kbuf.buffer = dtb; + kbuf.bufsz = dtb_len; + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; + kbuf.memsz = dtb_len; + /* not across 2MB boundary */ + kbuf.buf_align = SZ_2M; + kbuf.buf_max = ULONG_MAX; + kbuf.top_down = true; + + ret = kexec_add_buffer(&kbuf); + if (ret) + goto out_err; + image->arch.dtb = dtb; + image->arch.dtb_mem = kbuf.mem; + + pr_debug("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n", + kbuf.mem, kbuf.bufsz, kbuf.memsz); + + return 0; + +out_err: + image->nr_segments = orig_segments; + vfree(dtb); + return ret; +} |