| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * kexec: kexec_file_load system call |
| * |
| * Copyright (C) 2014 Red Hat Inc. |
| * Authors: |
| * Vivek Goyal <vgoyal@redhat.com> |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/capability.h> |
| #include <linux/mm.h> |
| #include <linux/file.h> |
| #include <linux/slab.h> |
| #include <linux/kexec.h> |
| #include <linux/memblock.h> |
| #include <linux/mutex.h> |
| #include <linux/list.h> |
| #include <linux/fs.h> |
| #include <linux/ima.h> |
| #include <crypto/hash.h> |
| #include <crypto/sha.h> |
| #include <linux/elf.h> |
| #include <linux/elfcore.h> |
| #include <linux/kernel.h> |
| #include <linux/syscalls.h> |
| #include <linux/vmalloc.h> |
| #include "kexec_internal.h" |
| |
| static int kexec_calculate_store_digests(struct kimage *image); |
| |
| /* |
| * Currently this is the only default function that is exported as some |
| * architectures need it to do additional handlings. |
| * In the future, other default functions may be exported too if required. |
| */ |
| int kexec_image_probe_default(struct kimage *image, void *buf, |
| unsigned long buf_len) |
| { |
| const struct kexec_file_ops * const *fops; |
| int ret = -ENOEXEC; |
| |
| for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) { |
| ret = (*fops)->probe(buf, buf_len); |
| if (!ret) { |
| image->fops = *fops; |
| return ret; |
| } |
| } |
| |
| return ret; |
| } |
| |
| /* Architectures can provide this probe function */ |
| int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf, |
| unsigned long buf_len) |
| { |
| return kexec_image_probe_default(image, buf, buf_len); |
| } |
| |
| static void *kexec_image_load_default(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); |
| } |
| |
| void * __weak arch_kexec_kernel_image_load(struct kimage *image) |
| { |
| return kexec_image_load_default(image); |
| } |
| |
| int kexec_image_post_load_cleanup_default(struct kimage *image) |
| { |
| if (!image->fops || !image->fops->cleanup) |
| return 0; |
| |
| return image->fops->cleanup(image->image_loader_data); |
| } |
| |
| int __weak arch_kimage_file_post_load_cleanup(struct kimage *image) |
| { |
| return kexec_image_post_load_cleanup_default(image); |
| } |
| |
| #ifdef CONFIG_KEXEC_SIG |
| static int kexec_image_verify_sig_default(struct kimage *image, void *buf, |
| unsigned long buf_len) |
| { |
| if (!image->fops || !image->fops->verify_sig) { |
| pr_debug("kernel loader does not support signature verification.\n"); |
| return -EKEYREJECTED; |
| } |
| |
| return image->fops->verify_sig(buf, buf_len); |
| } |
| |
| int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, |
| unsigned long buf_len) |
| { |
| return kexec_image_verify_sig_default(image, buf, buf_len); |
| } |
| #endif |
| |
| /* |
| * arch_kexec_apply_relocations_add - apply relocations of type RELA |
| * @pi: Purgatory to be relocated. |
| * @section: Section relocations applying to. |
| * @relsec: Section containing RELAs. |
| * @symtab: Corresponding symtab. |
| * |
| * Return: 0 on success, negative errno on error. |
| */ |
| int __weak |
| arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section, |
| const Elf_Shdr *relsec, const Elf_Shdr *symtab) |
| { |
| pr_err("RELA relocation unsupported.\n"); |
| return -ENOEXEC; |
| } |
| |
| /* |
| * arch_kexec_apply_relocations - apply relocations of type REL |
| * @pi: Purgatory to be relocated. |
| * @section: Section relocations applying to. |
| * @relsec: Section containing RELs. |
| * @symtab: Corresponding symtab. |
| * |
| * Return: 0 on success, negative errno on error. |
| */ |
| int __weak |
| arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section, |
| const Elf_Shdr *relsec, const Elf_Shdr *symtab) |
| { |
| pr_err("REL relocation unsupported.\n"); |
| return -ENOEXEC; |
| } |
| |
| /* |
| * Free up memory used by kernel, initrd, and command line. This is temporary |
| * memory allocation which is not needed any more after these buffers have |
| * been loaded into separate segments and have been copied elsewhere. |
| */ |
| void kimage_file_post_load_cleanup(struct kimage *image) |
| { |
| struct purgatory_info *pi = &image->purgatory_info; |
| |
| vfree(image->kernel_buf); |
| image->kernel_buf = NULL; |
| |
| vfree(image->initrd_buf); |
| image->initrd_buf = NULL; |
| |
| kfree(image->cmdline_buf); |
| image->cmdline_buf = NULL; |
| |
| vfree(pi->purgatory_buf); |
| pi->purgatory_buf = NULL; |
| |
| vfree(pi->sechdrs); |
| pi->sechdrs = NULL; |
| |
| #ifdef CONFIG_IMA_KEXEC |
| vfree(image->ima_buffer); |
| image->ima_buffer = NULL; |
| #endif /* CONFIG_IMA_KEXEC */ |
| |
| /* See if architecture has anything to cleanup post load */ |
| arch_kimage_file_post_load_cleanup(image); |
| |
| /* |
| * Above call should have called into bootloader to free up |
| * any data stored in kimage->image_loader_data. It should |
| * be ok now to free it up. |
| */ |
| kfree(image->image_loader_data); |
| image->image_loader_data = NULL; |
| } |
| |
| #ifdef CONFIG_KEXEC_SIG |
| static int |
| kimage_validate_signature(struct kimage *image) |
| { |
| const char *reason; |
| int ret; |
| |
| ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf, |
| image->kernel_buf_len); |
| switch (ret) { |
| case 0: |
| break; |
| |
| /* Certain verification errors are non-fatal if we're not |
| * checking errors, provided we aren't mandating that there |
| * must be a valid signature. |
| */ |
| case -ENODATA: |
| reason = "kexec of unsigned image"; |
| goto decide; |
| case -ENOPKG: |
| reason = "kexec of image with unsupported crypto"; |
| goto decide; |
| case -ENOKEY: |
| reason = "kexec of image with unavailable key"; |
| decide: |
| if (IS_ENABLED(CONFIG_KEXEC_SIG_FORCE)) { |
| pr_notice("%s rejected\n", reason); |
| return ret; |
| } |
| |
| /* If IMA is guaranteed to appraise a signature on the kexec |
| * image, permit it even if the kernel is otherwise locked |
| * down. |
| */ |
| if (!ima_appraise_signature(READING_KEXEC_IMAGE) && |
| security_locked_down(LOCKDOWN_KEXEC)) |
| return -EPERM; |
| |
| return 0; |
| |
| /* All other errors are fatal, including nomem, unparseable |
| * signatures and signature check failures - even if signatures |
| * aren't required. |
| */ |
| default: |
| pr_notice("kernel signature verification failed (%d).\n", ret); |
| } |
| |
| return ret; |
| } |
| #endif |
| |
| /* |
| * In file mode list of segments is prepared by kernel. Copy relevant |
| * data from user space, do error checking, prepare segment list |
| */ |
| static int |
| kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd, |
| const char __user *cmdline_ptr, |
| unsigned long cmdline_len, unsigned flags) |
| { |
| int ret; |
| void *ldata; |
| loff_t size; |
| |
| ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf, |
| &size, INT_MAX, READING_KEXEC_IMAGE); |
| if (ret) |
| return ret; |
| image->kernel_buf_len = size; |
| |
| /* Call arch image probe handlers */ |
| ret = arch_kexec_kernel_image_probe(image, image->kernel_buf, |
| image->kernel_buf_len); |
| if (ret) |
| goto out; |
| |
| #ifdef CONFIG_KEXEC_SIG |
| ret = kimage_validate_signature(image); |
| |
| if (ret) |
| goto out; |
| #endif |
| /* It is possible that there no initramfs is being loaded */ |
| if (!(flags & KEXEC_FILE_NO_INITRAMFS)) { |
| ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf, |
| &size, INT_MAX, |
| READING_KEXEC_INITRAMFS); |
| if (ret) |
| goto out; |
| image->initrd_buf_len = size; |
| } |
| |
| if (cmdline_len) { |
| image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len); |
| if (IS_ERR(image->cmdline_buf)) { |
| ret = PTR_ERR(image->cmdline_buf); |
| image->cmdline_buf = NULL; |
| goto out; |
| } |
| |
| image->cmdline_buf_len = cmdline_len; |
| |
| /* command line should be a string with last byte null */ |
| if (image->cmdline_buf[cmdline_len - 1] != '\0') { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| ima_kexec_cmdline(image->cmdline_buf, |
| image->cmdline_buf_len - 1); |
| } |
| |
| /* IMA needs to pass the measurement list to the next kernel. */ |
| ima_add_kexec_buffer(image); |
| |
| /* Call arch image load handlers */ |
| ldata = arch_kexec_kernel_image_load(image); |
| |
| if (IS_ERR(ldata)) { |
| ret = PTR_ERR(ldata); |
| goto out; |
| } |
| |
| image->image_loader_data = ldata; |
| out: |
| /* In case of error, free up all allocated memory in this function */ |
| if (ret) |
| kimage_file_post_load_cleanup(image); |
| return ret; |
| } |
| |
| static int |
| kimage_file_alloc_init(struct kimage **rimage, int kernel_fd, |
| int initrd_fd, const char __user *cmdline_ptr, |
| unsigned long cmdline_len, unsigned long flags) |
| { |
| int ret; |
| struct kimage *image; |
| bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH; |
| |
| image = do_kimage_alloc_init(); |
| if (!image) |
| return -ENOMEM; |
| |
| image->file_mode = 1; |
| |
| if (kexec_on_panic) { |
| /* Enable special crash kernel control page alloc policy. */ |
| image->control_page = crashk_res.start; |
| image->type = KEXEC_TYPE_CRASH; |
| } |
| |
| ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd, |
| cmdline_ptr, cmdline_len, flags); |
| if (ret) |
| goto out_free_image; |
| |
| ret = sanity_check_segment_list(image); |
| if (ret) |
| goto out_free_post_load_bufs; |
| |
| ret = -ENOMEM; |
| image->control_code_page = kimage_alloc_control_pages(image, |
| get_order(KEXEC_CONTROL_PAGE_SIZE)); |
| if (!image->control_code_page) { |
| pr_err("Could not allocate control_code_buffer\n"); |
| goto out_free_post_load_bufs; |
| } |
| |
| if (!kexec_on_panic) { |
| image->swap_page = kimage_alloc_control_pages(image, 0); |
| if (!image->swap_page) { |
| pr_err("Could not allocate swap buffer\n"); |
| goto out_free_control_pages; |
| } |
| } |
| |
| *rimage = image; |
| return 0; |
| out_free_control_pages: |
| kimage_free_page_list(&image->control_pages); |
| out_free_post_load_bufs: |
| kimage_file_post_load_cleanup(image); |
| out_free_image: |
| kfree(image); |
| return ret; |
| } |
| |
| SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd, |
| unsigned long, cmdline_len, const char __user *, cmdline_ptr, |
| unsigned long, flags) |
| { |
| int ret = 0, i; |
| struct kimage **dest_image, *image; |
| |
| /* We only trust the superuser with rebooting the system. */ |
| if (!capable(CAP_SYS_BOOT) || kexec_load_disabled) |
| return -EPERM; |
| |
| /* Make sure we have a legal set of flags */ |
| if (flags != (flags & KEXEC_FILE_FLAGS)) |
| return -EINVAL; |
| |
| image = NULL; |
| |
| if (!mutex_trylock(&kexec_mutex)) |
| return -EBUSY; |
| |
| dest_image = &kexec_image; |
| if (flags & KEXEC_FILE_ON_CRASH) { |
| dest_image = &kexec_crash_image; |
| if (kexec_crash_image) |
| arch_kexec_unprotect_crashkres(); |
| } |
| |
| if (flags & KEXEC_FILE_UNLOAD) |
| goto exchange; |
| |
| /* |
| * In case of crash, new kernel gets loaded in reserved region. It is |
| * same memory where old crash kernel might be loaded. Free any |
| * current crash dump kernel before we corrupt it. |
| */ |
| if (flags & KEXEC_FILE_ON_CRASH) |
| kimage_free(xchg(&kexec_crash_image, NULL)); |
| |
| ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr, |
| cmdline_len, flags); |
| if (ret) |
| goto out; |
| |
| ret = machine_kexec_prepare(image); |
| if (ret) |
| goto out; |
| |
| /* |
| * Some architecture(like S390) may touch the crash memory before |
| * machine_kexec_prepare(), we must copy vmcoreinfo data after it. |
| */ |
| ret = kimage_crash_copy_vmcoreinfo(image); |
| if (ret) |
| goto out; |
| |
| ret = kexec_calculate_store_digests(image); |
| if (ret) |
| goto out; |
| |
| for (i = 0; i < image->nr_segments; i++) { |
| struct kexec_segment *ksegment; |
| |
| ksegment = &image->segment[i]; |
| pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n", |
| i, ksegment->buf, ksegment->bufsz, ksegment->mem, |
| ksegment->memsz); |
| |
| ret = kimage_load_segment(image, &image->segment[i]); |
| if (ret) |
| goto out; |
| } |
| |
| kimage_terminate(image); |
| |
| /* |
| * Free up any temporary buffers allocated which are not needed |
| * after image has been loaded |
| */ |
| kimage_file_post_load_cleanup(image); |
| exchange: |
| image = xchg(dest_image, image); |
| out: |
| if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image) |
| arch_kexec_protect_crashkres(); |
| |
| mutex_unlock(&kexec_mutex); |
| kimage_free(image); |
| return ret; |
| } |
| |
| static int locate_mem_hole_top_down(unsigned long start, unsigned long end, |
| struct kexec_buf *kbuf) |
| { |
| struct kimage *image = kbuf->image; |
| unsigned long temp_start, temp_end; |
| |
| temp_end = min(end, kbuf->buf_max); |
| temp_start = temp_end - kbuf->memsz; |
| |
| do { |
| /* align down start */ |
| temp_start = temp_start & (~(kbuf->buf_align - 1)); |
| |
| if (temp_start < start || temp_start < kbuf->buf_min) |
| return 0; |
| |
| temp_end = temp_start + kbuf->memsz - 1; |
| |
| /* |
| * Make sure this does not conflict with any of existing |
| * segments |
| */ |
| if (kimage_is_destination_range(image, temp_start, temp_end)) { |
| temp_start = temp_start - PAGE_SIZE; |
| continue; |
| } |
| |
| /* We found a suitable memory range */ |
| break; |
| } while (1); |
| |
| /* If we are here, we found a suitable memory range */ |
| kbuf->mem = temp_start; |
| |
| /* Success, stop navigating through remaining System RAM ranges */ |
| return 1; |
| } |
| |
| static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end, |
| struct kexec_buf *kbuf) |
| { |
| struct kimage *image = kbuf->image; |
| unsigned long temp_start, temp_end; |
| |
| temp_start = max(start, kbuf->buf_min); |
| |
| do { |
| temp_start = ALIGN(temp_start, kbuf->buf_align); |
| temp_end = temp_start + kbuf->memsz - 1; |
| |
| if (temp_end > end || temp_end > kbuf->buf_max) |
| return 0; |
| /* |
| * Make sure this does not conflict with any of existing |
| * segments |
| */ |
| if (kimage_is_destination_range(image, temp_start, temp_end)) { |
| temp_start = temp_start + PAGE_SIZE; |
| continue; |
| } |
| |
| /* We found a suitable memory range */ |
| break; |
| } while (1); |
| |
| /* If we are here, we found a suitable memory range */ |
| kbuf->mem = temp_start; |
| |
| /* Success, stop navigating through remaining System RAM ranges */ |
| return 1; |
| } |
| |
| static int locate_mem_hole_callback(struct resource *res, void *arg) |
| { |
| struct kexec_buf *kbuf = (struct kexec_buf *)arg; |
| u64 start = res->start, end = res->end; |
| unsigned long sz = end - start + 1; |
| |
| /* Returning 0 will take to next memory range */ |
| if (sz < kbuf->memsz) |
| return 0; |
| |
| if (end < kbuf->buf_min || start > kbuf->buf_max) |
| return 0; |
| |
| /* |
| * Allocate memory top down with-in ram range. Otherwise bottom up |
| * allocation. |
| */ |
| if (kbuf->top_down) |
| return locate_mem_hole_top_down(start, end, kbuf); |
| return locate_mem_hole_bottom_up(start, end, kbuf); |
| } |
| |
| #ifdef CONFIG_ARCH_KEEP_MEMBLOCK |
| static int kexec_walk_memblock(struct kexec_buf *kbuf, |
| int (*func)(struct resource *, void *)) |
| { |
| int ret = 0; |
| u64 i; |
| phys_addr_t mstart, mend; |
| struct resource res = { }; |
| |
| if (kbuf->image->type == KEXEC_TYPE_CRASH) |
| return func(&crashk_res, kbuf); |
| |
| if (kbuf->top_down) { |
| for_each_free_mem_range_reverse(i, NUMA_NO_NODE, MEMBLOCK_NONE, |
| &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. |
| */ |
| res.start = mstart; |
| res.end = mend - 1; |
| ret = func(&res, kbuf); |
| if (ret) |
| break; |
| } |
| } else { |
| for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, |
| &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. |
| */ |
| res.start = mstart; |
| res.end = mend - 1; |
| ret = func(&res, kbuf); |
| if (ret) |
| break; |
| } |
| } |
| |
| return ret; |
| } |
| #else |
| static int kexec_walk_memblock(struct kexec_buf *kbuf, |
| int (*func)(struct resource *, void *)) |
| { |
| return 0; |
| } |
| #endif |
| |
| /** |
| * kexec_walk_resources - call func(data) on free memory regions |
| * @kbuf: Context info for the search. Also passed to @func. |
| * @func: Function to call for each memory region. |
| * |
| * 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. |
| */ |
| static int kexec_walk_resources(struct kexec_buf *kbuf, |
| int (*func)(struct resource *, void *)) |
| { |
| if (kbuf->image->type == KEXEC_TYPE_CRASH) |
| return walk_iomem_res_desc(crashk_res.desc, |
| IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY, |
| crashk_res.start, crashk_res.end, |
| kbuf, func); |
| else |
| return walk_system_ram_res(0, ULONG_MAX, kbuf, func); |
| } |
| |
| /** |
| * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel |
| * @kbuf: Parameters for the memory search. |
| * |
| * On success, kbuf->mem will have the start address of the memory region found. |
| * |
| * Return: 0 on success, negative errno on error. |
| */ |
| int kexec_locate_mem_hole(struct kexec_buf *kbuf) |
| { |
| int ret; |
| |
| /* Arch knows where to place */ |
| if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN) |
| return 0; |
| |
| if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) |
| ret = kexec_walk_resources(kbuf, locate_mem_hole_callback); |
| else |
| ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback); |
| |
| return ret == 1 ? 0 : -EADDRNOTAVAIL; |
| } |
| |
| /** |
| * kexec_add_buffer - place a buffer in a kexec segment |
| * @kbuf: Buffer contents and memory parameters. |
| * |
| * This function assumes that kexec_mutex is held. |
| * On successful return, @kbuf->mem will have the physical address of |
| * the buffer in memory. |
| * |
| * Return: 0 on success, negative errno on error. |
| */ |
| int kexec_add_buffer(struct kexec_buf *kbuf) |
| { |
| |
| struct kexec_segment *ksegment; |
| int ret; |
| |
| /* Currently adding segment this way is allowed only in file mode */ |
| if (!kbuf->image->file_mode) |
| return -EINVAL; |
| |
| if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX) |
| return -EINVAL; |
| |
| /* |
| * Make sure we are not trying to add buffer after allocating |
| * control pages. All segments need to be placed first before |
| * any control pages are allocated. As control page allocation |
| * logic goes through list of segments to make sure there are |
| * no destination overlaps. |
| */ |
| if (!list_empty(&kbuf->image->control_pages)) { |
| WARN_ON(1); |
| return -EINVAL; |
| } |
| |
| /* Ensure minimum alignment needed for segments. */ |
| kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE); |
| kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE); |
| |
| /* Walk the RAM ranges and allocate a suitable range for the buffer */ |
| ret = kexec_locate_mem_hole(kbuf); |
| if (ret) |
| return ret; |
| |
| /* Found a suitable memory range */ |
| ksegment = &kbuf->image->segment[kbuf->image->nr_segments]; |
| ksegment->kbuf = kbuf->buffer; |
| ksegment->bufsz = kbuf->bufsz; |
| ksegment->mem = kbuf->mem; |
| ksegment->memsz = kbuf->memsz; |
| kbuf->image->nr_segments++; |
| return 0; |
| } |
| |
| /* Calculate and store the digest of segments */ |
| static int kexec_calculate_store_digests(struct kimage *image) |
| { |
| struct crypto_shash *tfm; |
| struct shash_desc *desc; |
| int ret = 0, i, j, zero_buf_sz, sha_region_sz; |
| size_t desc_size, nullsz; |
| char *digest; |
| void *zero_buf; |
| struct kexec_sha_region *sha_regions; |
| struct purgatory_info *pi = &image->purgatory_info; |
| |
| if (!IS_ENABLED(CONFIG_ARCH_HAS_KEXEC_PURGATORY)) |
| return 0; |
| |
| zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT); |
| zero_buf_sz = PAGE_SIZE; |
| |
| tfm = crypto_alloc_shash("sha256", 0, 0); |
| if (IS_ERR(tfm)) { |
| ret = PTR_ERR(tfm); |
| goto out; |
| } |
| |
| desc_size = crypto_shash_descsize(tfm) + sizeof(*desc); |
| desc = kzalloc(desc_size, GFP_KERNEL); |
| if (!desc) { |
| ret = -ENOMEM; |
| goto out_free_tfm; |
| } |
| |
| sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region); |
| sha_regions = vzalloc(sha_region_sz); |
| if (!sha_regions) |
| goto out_free_desc; |
| |
| desc->tfm = tfm; |
| |
| ret = crypto_shash_init(desc); |
| if (ret < 0) |
| goto out_free_sha_regions; |
| |
| digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); |
| if (!digest) { |
| ret = -ENOMEM; |
| goto out_free_sha_regions; |
| } |
| |
| for (j = i = 0; i < image->nr_segments; i++) { |
| struct kexec_segment *ksegment; |
| |
| ksegment = &image->segment[i]; |
| /* |
| * Skip purgatory as it will be modified once we put digest |
| * info in purgatory. |
| */ |
| if (ksegment->kbuf == pi->purgatory_buf) |
| continue; |
| |
| ret = crypto_shash_update(desc, ksegment->kbuf, |
| ksegment->bufsz); |
| if (ret) |
| break; |
| |
| /* |
| * Assume rest of the buffer is filled with zero and |
| * update digest accordingly. |
| */ |
| nullsz = ksegment->memsz - ksegment->bufsz; |
| while (nullsz) { |
| unsigned long bytes = nullsz; |
| |
| if (bytes > zero_buf_sz) |
| bytes = zero_buf_sz; |
| ret = crypto_shash_update(desc, zero_buf, bytes); |
| if (ret) |
| break; |
| nullsz -= bytes; |
| } |
| |
| if (ret) |
| break; |
| |
| sha_regions[j].start = ksegment->mem; |
| sha_regions[j].len = ksegment->memsz; |
| j++; |
| } |
| |
| if (!ret) { |
| ret = crypto_shash_final(desc, digest); |
| if (ret) |
| goto out_free_digest; |
| ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha_regions", |
| sha_regions, sha_region_sz, 0); |
| if (ret) |
| goto out_free_digest; |
| |
| ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest", |
| digest, SHA256_DIGEST_SIZE, 0); |
| if (ret) |
| goto out_free_digest; |
| } |
| |
| out_free_digest: |
| kfree(digest); |
| out_free_sha_regions: |
| vfree(sha_regions); |
| out_free_desc: |
| kfree(desc); |
| out_free_tfm: |
| kfree(tfm); |
| out: |
| return ret; |
| } |
| |
| #ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY |
| /* |
| * kexec_purgatory_setup_kbuf - prepare buffer to load purgatory. |
| * @pi: Purgatory to be loaded. |
| * @kbuf: Buffer to setup. |
| * |
| * Allocates the memory needed for the buffer. Caller is responsible to free |
| * the memory after use. |
| * |
| * Return: 0 on success, negative errno on error. |
| */ |
| static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi, |
| struct kexec_buf *kbuf) |
| { |
| const Elf_Shdr *sechdrs; |
| unsigned long bss_align; |
| unsigned long bss_sz; |
| unsigned long align; |
| int i, ret; |
| |
| sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff; |
| kbuf->buf_align = bss_align = 1; |
| kbuf->bufsz = bss_sz = 0; |
| |
| for (i = 0; i < pi->ehdr->e_shnum; i++) { |
| if (!(sechdrs[i].sh_flags & SHF_ALLOC)) |
| continue; |
| |
| align = sechdrs[i].sh_addralign; |
| if (sechdrs[i].sh_type != SHT_NOBITS) { |
| if (kbuf->buf_align < align) |
| kbuf->buf_align = align; |
| kbuf->bufsz = ALIGN(kbuf->bufsz, align); |
| kbuf->bufsz += sechdrs[i].sh_size; |
| } else { |
| if (bss_align < align) |
| bss_align = align; |
| bss_sz = ALIGN(bss_sz, align); |
| bss_sz += sechdrs[i].sh_size; |
| } |
| } |
| kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align); |
| kbuf->memsz = kbuf->bufsz + bss_sz; |
| if (kbuf->buf_align < bss_align) |
| kbuf->buf_align = bss_align; |
| |
| kbuf->buffer = vzalloc(kbuf->bufsz); |
| if (!kbuf->buffer) |
| return -ENOMEM; |
| pi->purgatory_buf = kbuf->buffer; |
| |
| ret = kexec_add_buffer(kbuf); |
| if (ret) |
| goto out; |
| |
| return 0; |
| out: |
| vfree(pi->purgatory_buf); |
| pi->purgatory_buf = NULL; |
| return ret; |
| } |
| |
| /* |
| * kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer. |
| * @pi: Purgatory to be loaded. |
| * @kbuf: Buffer prepared to store purgatory. |
| * |
| * Allocates the memory needed for the buffer. Caller is responsible to free |
| * the memory after use. |
| * |
| * Return: 0 on success, negative errno on error. |
| */ |
| static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi, |
| struct kexec_buf *kbuf) |
| { |
| unsigned long bss_addr; |
| unsigned long offset; |
| Elf_Shdr *sechdrs; |
| int i; |
| |
| /* |
| * The section headers in kexec_purgatory are read-only. In order to |
| * have them modifiable make a temporary copy. |
| */ |
| sechdrs = vzalloc(array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum)); |
| if (!sechdrs) |
| return -ENOMEM; |
| memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff, |
| pi->ehdr->e_shnum * sizeof(Elf_Shdr)); |
| pi->sechdrs = sechdrs; |
| |
| offset = 0; |
| bss_addr = kbuf->mem + kbuf->bufsz; |
| kbuf->image->start = pi->ehdr->e_entry; |
| |
| for (i = 0; i < pi->ehdr->e_shnum; i++) { |
| unsigned long align; |
| void *src, *dst; |
| |
| if (!(sechdrs[i].sh_flags & SHF_ALLOC)) |
| continue; |
| |
| align = sechdrs[i].sh_addralign; |
| if (sechdrs[i].sh_type == SHT_NOBITS) { |
| bss_addr = ALIGN(bss_addr, align); |
| sechdrs[i].sh_addr = bss_addr; |
| bss_addr += sechdrs[i].sh_size; |
| continue; |
| } |
| |
| offset = ALIGN(offset, align); |
| if (sechdrs[i].sh_flags & SHF_EXECINSTR && |
| pi->ehdr->e_entry >= sechdrs[i].sh_addr && |
| pi->ehdr->e_entry < (sechdrs[i].sh_addr |
| + sechdrs[i].sh_size)) { |
| kbuf->image->start -= sechdrs[i].sh_addr; |
| kbuf->image->start += kbuf->mem + offset; |
| } |
| |
| src = (void *)pi->ehdr + sechdrs[i].sh_offset; |
| dst = pi->purgatory_buf + offset; |
| memcpy(dst, src, sechdrs[i].sh_size); |
| |
| sechdrs[i].sh_addr = kbuf->mem + offset; |
| sechdrs[i].sh_offset = offset; |
| offset += sechdrs[i].sh_size; |
| } |
| |
| return 0; |
| } |
| |
| static int kexec_apply_relocations(struct kimage *image) |
| { |
| int i, ret; |
| struct purgatory_info *pi = &image->purgatory_info; |
| const Elf_Shdr *sechdrs; |
| |
| sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff; |
| |
| for (i = 0; i < pi->ehdr->e_shnum; i++) { |
| const Elf_Shdr *relsec; |
| const Elf_Shdr *symtab; |
| Elf_Shdr *section; |
| |
| relsec = sechdrs + i; |
| |
| if (relsec->sh_type != SHT_RELA && |
| relsec->sh_type != SHT_REL) |
| continue; |
| |
| /* |
| * For section of type SHT_RELA/SHT_REL, |
| * ->sh_link contains section header index of associated |
| * symbol table. And ->sh_info contains section header |
| * index of section to which relocations apply. |
| */ |
| if (relsec->sh_info >= pi->ehdr->e_shnum || |
| relsec->sh_link >= pi->ehdr->e_shnum) |
| return -ENOEXEC; |
| |
| section = pi->sechdrs + relsec->sh_info; |
| symtab = sechdrs + relsec->sh_link; |
| |
| if (!(section->sh_flags & SHF_ALLOC)) |
| continue; |
| |
| /* |
| * symtab->sh_link contain section header index of associated |
| * string table. |
| */ |
| if (symtab->sh_link >= pi->ehdr->e_shnum) |
| /* Invalid section number? */ |
| continue; |
| |
| /* |
| * Respective architecture needs to provide support for applying |
| * relocations of type SHT_RELA/SHT_REL. |
| */ |
| if (relsec->sh_type == SHT_RELA) |
| ret = arch_kexec_apply_relocations_add(pi, section, |
| relsec, symtab); |
| else if (relsec->sh_type == SHT_REL) |
| ret = arch_kexec_apply_relocations(pi, section, |
| relsec, symtab); |
| if (ret) |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * kexec_load_purgatory - Load and relocate the purgatory object. |
| * @image: Image to add the purgatory to. |
| * @kbuf: Memory parameters to use. |
| * |
| * Allocates the memory needed for image->purgatory_info.sechdrs and |
| * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible |
| * to free the memory after use. |
| * |
| * Return: 0 on success, negative errno on error. |
| */ |
| int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf) |
| { |
| struct purgatory_info *pi = &image->purgatory_info; |
| int ret; |
| |
| if (kexec_purgatory_size <= 0) |
| return -EINVAL; |
| |
| pi->ehdr = (const Elf_Ehdr *)kexec_purgatory; |
| |
| ret = kexec_purgatory_setup_kbuf(pi, kbuf); |
| if (ret) |
| return ret; |
| |
| ret = kexec_purgatory_setup_sechdrs(pi, kbuf); |
| if (ret) |
| goto out_free_kbuf; |
| |
| ret = kexec_apply_relocations(image); |
| if (ret) |
| goto out; |
| |
| return 0; |
| out: |
| vfree(pi->sechdrs); |
| pi->sechdrs = NULL; |
| out_free_kbuf: |
| vfree(pi->purgatory_buf); |
| pi->purgatory_buf = NULL; |
| return ret; |
| } |
| |
| /* |
| * kexec_purgatory_find_symbol - find a symbol in the purgatory |
| * @pi: Purgatory to search in. |
| * @name: Name of the symbol. |
| * |
| * Return: pointer to symbol in read-only symtab on success, NULL on error. |
| */ |
| static const Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi, |
| const char *name) |
| { |
| const Elf_Shdr *sechdrs; |
| const Elf_Ehdr *ehdr; |
| const Elf_Sym *syms; |
| const char *strtab; |
| int i, k; |
| |
| if (!pi->ehdr) |
| return NULL; |
| |
| ehdr = pi->ehdr; |
| sechdrs = (void *)ehdr + ehdr->e_shoff; |
| |
| for (i = 0; i < ehdr->e_shnum; i++) { |
| if (sechdrs[i].sh_type != SHT_SYMTAB) |
| continue; |
| |
| if (sechdrs[i].sh_link >= ehdr->e_shnum) |
| /* Invalid strtab section number */ |
| continue; |
| strtab = (void *)ehdr + sechdrs[sechdrs[i].sh_link].sh_offset; |
| syms = (void *)ehdr + sechdrs[i].sh_offset; |
| |
| /* Go through symbols for a match */ |
| for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) { |
| if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL) |
| continue; |
| |
| if (strcmp(strtab + syms[k].st_name, name) != 0) |
| continue; |
| |
| if (syms[k].st_shndx == SHN_UNDEF || |
| syms[k].st_shndx >= ehdr->e_shnum) { |
| pr_debug("Symbol: %s has bad section index %d.\n", |
| name, syms[k].st_shndx); |
| return NULL; |
| } |
| |
| /* Found the symbol we are looking for */ |
| return &syms[k]; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name) |
| { |
| struct purgatory_info *pi = &image->purgatory_info; |
| const Elf_Sym *sym; |
| Elf_Shdr *sechdr; |
| |
| sym = kexec_purgatory_find_symbol(pi, name); |
| if (!sym) |
| return ERR_PTR(-EINVAL); |
| |
| sechdr = &pi->sechdrs[sym->st_shndx]; |
| |
| /* |
| * Returns the address where symbol will finally be loaded after |
| * kexec_load_segment() |
| */ |
| return (void *)(sechdr->sh_addr + sym->st_value); |
| } |
| |
| /* |
| * Get or set value of a symbol. If "get_value" is true, symbol value is |
| * returned in buf otherwise symbol value is set based on value in buf. |
| */ |
| int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name, |
| void *buf, unsigned int size, bool get_value) |
| { |
| struct purgatory_info *pi = &image->purgatory_info; |
| const Elf_Sym *sym; |
| Elf_Shdr *sec; |
| char *sym_buf; |
| |
| sym = kexec_purgatory_find_symbol(pi, name); |
| if (!sym) |
| return -EINVAL; |
| |
| if (sym->st_size != size) { |
| pr_err("symbol %s size mismatch: expected %lu actual %u\n", |
| name, (unsigned long)sym->st_size, size); |
| return -EINVAL; |
| } |
| |
| sec = pi->sechdrs + sym->st_shndx; |
| |
| if (sec->sh_type == SHT_NOBITS) { |
| pr_err("symbol %s is in a bss section. Cannot %s\n", name, |
| get_value ? "get" : "set"); |
| return -EINVAL; |
| } |
| |
| sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value; |
| |
| if (get_value) |
| memcpy((void *)buf, sym_buf, size); |
| else |
| memcpy((void *)sym_buf, buf, size); |
| |
| return 0; |
| } |
| #endif /* CONFIG_ARCH_HAS_KEXEC_PURGATORY */ |
| |
| int crash_exclude_mem_range(struct crash_mem *mem, |
| unsigned long long mstart, unsigned long long mend) |
| { |
| int i, j; |
| unsigned long long start, end; |
| struct crash_mem_range temp_range = {0, 0}; |
| |
| for (i = 0; i < mem->nr_ranges; i++) { |
| start = mem->ranges[i].start; |
| end = mem->ranges[i].end; |
| |
| if (mstart > end || mend < start) |
| continue; |
| |
| /* Truncate any area outside of range */ |
| if (mstart < start) |
| mstart = start; |
| if (mend > end) |
| mend = end; |
| |
| /* Found completely overlapping range */ |
| if (mstart == start && mend == end) { |
| mem->ranges[i].start = 0; |
| mem->ranges[i].end = 0; |
| if (i < mem->nr_ranges - 1) { |
| /* Shift rest of the ranges to left */ |
| for (j = i; j < mem->nr_ranges - 1; j++) { |
| mem->ranges[j].start = |
| mem->ranges[j+1].start; |
| mem->ranges[j].end = |
| mem->ranges[j+1].end; |
| } |
| } |
| mem->nr_ranges--; |
| return 0; |
| } |
| |
| if (mstart > start && mend < end) { |
| /* Split original range */ |
| mem->ranges[i].end = mstart - 1; |
| temp_range.start = mend + 1; |
| temp_range.end = end; |
| } else if (mstart != start) |
| mem->ranges[i].end = mstart - 1; |
| else |
| mem->ranges[i].start = mend + 1; |
| break; |
| } |
| |
| /* If a split happened, add the split to array */ |
| if (!temp_range.end) |
| return 0; |
| |
| /* Split happened */ |
| if (i == mem->max_nr_ranges - 1) |
| return -ENOMEM; |
| |
| /* Location where new range should go */ |
| j = i + 1; |
| if (j < mem->nr_ranges) { |
| /* Move over all ranges one slot towards the end */ |
| for (i = mem->nr_ranges - 1; i >= j; i--) |
| mem->ranges[i + 1] = mem->ranges[i]; |
| } |
| |
| mem->ranges[j].start = temp_range.start; |
| mem->ranges[j].end = temp_range.end; |
| mem->nr_ranges++; |
| return 0; |
| } |
| |
| int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map, |
| void **addr, unsigned long *sz) |
| { |
| Elf64_Ehdr *ehdr; |
| Elf64_Phdr *phdr; |
| unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz; |
| unsigned char *buf; |
| unsigned int cpu, i; |
| unsigned long long notes_addr; |
| unsigned long mstart, mend; |
| |
| /* extra phdr for vmcoreinfo elf note */ |
| nr_phdr = nr_cpus + 1; |
| nr_phdr += mem->nr_ranges; |
| |
| /* |
| * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping |
| * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64). |
| * I think this is required by tools like gdb. So same physical |
| * memory will be mapped in two elf headers. One will contain kernel |
| * text virtual addresses and other will have __va(physical) addresses. |
| */ |
| |
| nr_phdr++; |
| elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr); |
| elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN); |
| |
| buf = vzalloc(elf_sz); |
| if (!buf) |
| return -ENOMEM; |
| |
| ehdr = (Elf64_Ehdr *)buf; |
| phdr = (Elf64_Phdr *)(ehdr + 1); |
| memcpy(ehdr->e_ident, ELFMAG, SELFMAG); |
| ehdr->e_ident[EI_CLASS] = ELFCLASS64; |
| ehdr->e_ident[EI_DATA] = ELFDATA2LSB; |
| ehdr->e_ident[EI_VERSION] = EV_CURRENT; |
| ehdr->e_ident[EI_OSABI] = ELF_OSABI; |
| memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD); |
| ehdr->e_type = ET_CORE; |
| ehdr->e_machine = ELF_ARCH; |
| ehdr->e_version = EV_CURRENT; |
| ehdr->e_phoff = sizeof(Elf64_Ehdr); |
| ehdr->e_ehsize = sizeof(Elf64_Ehdr); |
| ehdr->e_phentsize = sizeof(Elf64_Phdr); |
| |
| /* Prepare one phdr of type PT_NOTE for each present cpu */ |
| for_each_present_cpu(cpu) { |
| phdr->p_type = PT_NOTE; |
| notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu)); |
| phdr->p_offset = phdr->p_paddr = notes_addr; |
| phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t); |
| (ehdr->e_phnum)++; |
| phdr++; |
| } |
| |
| /* Prepare one PT_NOTE header for vmcoreinfo */ |
| phdr->p_type = PT_NOTE; |
| phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note(); |
| phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE; |
| (ehdr->e_phnum)++; |
| phdr++; |
| |
| /* Prepare PT_LOAD type program header for kernel text region */ |
| if (kernel_map) { |
| phdr->p_type = PT_LOAD; |
| phdr->p_flags = PF_R|PF_W|PF_X; |
| phdr->p_vaddr = (Elf64_Addr)_text; |
| phdr->p_filesz = phdr->p_memsz = _end - _text; |
| phdr->p_offset = phdr->p_paddr = __pa_symbol(_text); |
| ehdr->e_phnum++; |
| phdr++; |
| } |
| |
| /* Go through all the ranges in mem->ranges[] and prepare phdr */ |
| for (i = 0; i < mem->nr_ranges; i++) { |
| mstart = mem->ranges[i].start; |
| mend = mem->ranges[i].end; |
| |
| phdr->p_type = PT_LOAD; |
| phdr->p_flags = PF_R|PF_W|PF_X; |
| phdr->p_offset = mstart; |
| |
| phdr->p_paddr = mstart; |
| phdr->p_vaddr = (unsigned long long) __va(mstart); |
| phdr->p_filesz = phdr->p_memsz = mend - mstart + 1; |
| phdr->p_align = 0; |
| ehdr->e_phnum++; |
| phdr++; |
| pr_debug("Crash PT_LOAD elf header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n", |
| phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz, |
| ehdr->e_phnum, phdr->p_offset); |
| } |
| |
| *addr = buf; |
| *sz = elf_sz; |
| return 0; |
| } |