diff options
Diffstat (limited to 'kernel/kexec_file.c')
| -rw-r--r-- | kernel/kexec_file.c | 885 |
1 files changed, 553 insertions, 332 deletions
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 9f48f4412297..eb62a9794242 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -1,12 +1,10 @@ +// 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> - * - * This source code is licensed under the GNU General Public License, - * Version 2. See the file COPYING for more details. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt @@ -16,59 +14,89 @@ #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 <crypto/sha2.h> +#include <linux/elf.h> +#include <linux/elfcore.h> +#include <linux/kernel.h> +#include <linux/kernel_read_file.h> #include <linux/syscalls.h> #include <linux/vmalloc.h> +#include <linux/dma-map-ops.h> #include "kexec_internal.h" -static int kexec_calculate_store_digests(struct kimage *image); +#ifdef CONFIG_KEXEC_SIG +static bool sig_enforce = IS_ENABLED(CONFIG_KEXEC_SIG_FORCE); -/* Architectures can provide this probe function */ -int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf, - unsigned long buf_len) +void set_kexec_sig_enforced(void) { - return -ENOEXEC; + sig_enforce = true; } +#endif -void * __weak arch_kexec_kernel_image_load(struct kimage *image) +#ifdef CONFIG_IMA_KEXEC +static bool check_ima_segment_index(struct kimage *image, int i) { - return ERR_PTR(-ENOEXEC); + if (image->is_ima_segment_index_set && i == image->ima_segment_index) + return true; + else + return false; } - -int __weak arch_kimage_file_post_load_cleanup(struct kimage *image) +#else +static bool check_ima_segment_index(struct kimage *image, int i) { - return -EINVAL; + return false; } +#endif + +static int kexec_calculate_store_digests(struct kimage *image); -#ifdef CONFIG_KEXEC_VERIFY_SIG -int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, - unsigned long buf_len) +/* Maximum size in bytes for kernel/initrd files. */ +#define KEXEC_FILE_SIZE_MAX min_t(s64, 4LL << 30, SSIZE_MAX) + +/* + * 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) { - return -EKEYREJECTED; + 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; } -#endif -/* Apply relocations of type RELA */ -int __weak -arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, - unsigned int relsec) +static void *kexec_image_load_default(struct kimage *image) { - pr_err("RELA relocation unsupported.\n"); - return -ENOEXEC; + 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); } -/* Apply relocations of type REL */ -int __weak -arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, - unsigned int relsec) +int kexec_image_post_load_cleanup_default(struct kimage *image) { - pr_err("REL relocation unsupported.\n"); - return -ENOEXEC; + if (!image->fops || !image->fops->cleanup) + return 0; + + return image->fops->cleanup(image->image_loader_data); } /* @@ -95,6 +123,11 @@ void kimage_file_post_load_cleanup(struct kimage *image) 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); @@ -105,6 +138,76 @@ void kimage_file_post_load_cleanup(struct kimage *image) */ kfree(image->image_loader_data); image->image_loader_data = NULL; + + kexec_file_dbg_print = false; +} + +#ifdef CONFIG_KEXEC_SIG +#ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION +int kexec_kernel_verify_pe_sig(const char *kernel, unsigned long kernel_len) +{ + int ret; + + ret = verify_pefile_signature(kernel, kernel_len, + VERIFY_USE_SECONDARY_KEYRING, + VERIFYING_KEXEC_PE_SIGNATURE); + if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) { + ret = verify_pefile_signature(kernel, kernel_len, + VERIFY_USE_PLATFORM_KEYRING, + VERIFYING_KEXEC_PE_SIGNATURE); + } + return ret; +} +#endif + +static int kexec_image_verify_sig(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); +} + +static int +kimage_validate_signature(struct kimage *image) +{ + int ret; + + ret = kexec_image_verify_sig(image, image->kernel_buf, + image->kernel_buf_len); + if (ret) { + + if (sig_enforce) { + pr_notice("Enforced kernel signature verification failed (%d).\n", ret); + 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; + + pr_debug("kernel signature verification failed (%d).\n", ret); + } + + return 0; +} +#endif + +static int kexec_post_load(struct kimage *image, unsigned long flags) +{ +#ifdef CONFIG_IMA_KEXEC + if (!(flags & KEXEC_FILE_ON_CRASH)) + ima_kexec_post_load(image); +#endif + return machine_kexec_post_load(image); } /* @@ -116,18 +219,17 @@ 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 = 0; + ssize_t 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) + ret = kernel_read_file_from_fd(kernel_fd, 0, &image->kernel_buf, + KEXEC_FILE_SIZE_MAX, NULL, + READING_KEXEC_IMAGE); + if (ret < 0) return ret; - image->kernel_buf_len = size; - - /* IMA needs to pass the measurement list to the next kernel. */ - ima_add_kexec_buffer(image); + image->kernel_buf_len = ret; + kexec_dprintk("kernel: %p kernel_size: %#lx\n", + image->kernel_buf, image->kernel_buf_len); /* Call arch image probe handlers */ ret = arch_kexec_kernel_image_probe(image, image->kernel_buf, @@ -135,25 +237,26 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd, if (ret) goto out; -#ifdef CONFIG_KEXEC_VERIFY_SIG - ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf, - image->kernel_buf_len); - if (ret) { - pr_debug("kernel signature verification failed.\n"); +#ifdef CONFIG_KEXEC_SIG + ret = kimage_validate_signature(image); + + if (ret) goto out; - } - pr_debug("kernel signature verification successful.\n"); #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, + ret = kernel_read_file_from_fd(initrd_fd, 0, &image->initrd_buf, + KEXEC_FILE_SIZE_MAX, NULL, READING_KEXEC_INITRAMFS); - if (ret) + if (ret < 0) goto out; - image->initrd_buf_len = size; + image->initrd_buf_len = ret; + ret = 0; } + image->no_cma = !!(flags & KEXEC_FILE_NO_CMA); + image->force_dtb = flags & KEXEC_FILE_FORCE_DTB; + if (cmdline_len) { image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len); if (IS_ERR(image->cmdline_buf)) { @@ -169,10 +272,21 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd, ret = -EINVAL; goto out; } + + ima_kexec_cmdline(kernel_fd, image->cmdline_buf, + image->cmdline_buf_len - 1); } - /* Call arch image load handlers */ - ldata = arch_kexec_kernel_image_load(image); + /* IMA needs to pass the measurement list to the next kernel. */ + ima_add_kexec_buffer(image); + + /* If KHO is active, add its images to the list */ + ret = kho_fill_kimage(image); + if (ret) + goto out; + + /* Call image load handler */ + ldata = kexec_image_load_default(image); if (IS_ERR(ldata)) { ret = PTR_ERR(ldata); @@ -200,13 +314,16 @@ kimage_file_alloc_init(struct kimage **rimage, int kernel_fd, if (!image) return -ENOMEM; + kexec_file_dbg_print = !!(flags & KEXEC_FILE_DEBUG); image->file_mode = 1; +#ifdef CONFIG_CRASH_DUMP if (kexec_on_panic) { /* Enable special crash kernel control page alloc policy. */ image->control_page = crashk_res.start; image->type = KEXEC_TYPE_CRASH; } +#endif ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd, cmdline_ptr, cmdline_len, flags); @@ -248,11 +365,13 @@ 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; + int image_type = (flags & KEXEC_FILE_ON_CRASH) ? + KEXEC_TYPE_CRASH : KEXEC_TYPE_DEFAULT; struct kimage **dest_image, *image; + int ret = 0, i; /* We only trust the superuser with rebooting the system. */ - if (!capable(CAP_SYS_BOOT) || kexec_load_disabled) + if (!kexec_load_permitted(image_type)) return -EPERM; /* Make sure we have a legal set of flags */ @@ -261,15 +380,17 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd, image = NULL; - if (!mutex_trylock(&kexec_mutex)) + if (!kexec_trylock()) return -EBUSY; - dest_image = &kexec_image; - if (flags & KEXEC_FILE_ON_CRASH) { +#ifdef CONFIG_CRASH_DUMP + if (image_type == KEXEC_TYPE_CRASH) { dest_image = &kexec_crash_image; if (kexec_crash_image) arch_kexec_unprotect_crashkres(); - } + } else +#endif + dest_image = &kexec_image; if (flags & KEXEC_FILE_UNLOAD) goto exchange; @@ -287,6 +408,11 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd, if (ret) goto out; +#ifdef CONFIG_CRASH_HOTPLUG + if ((flags & KEXEC_FILE_ON_CRASH) && arch_crash_hotplug_support(image, flags)) + image->hotplug_support = 1; +#endif + ret = machine_kexec_prepare(image); if (ret) goto out; @@ -303,21 +429,28 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd, if (ret) goto out; + kexec_dprintk("nr_segments = %lu\n", image->nr_segments); 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); + kexec_dprintk("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]); + ret = kimage_load_segment(image, i); if (ret) goto out; } kimage_terminate(image); + ret = kexec_post_load(image, flags); + if (ret) + goto out; + + kexec_dprintk("kexec_file_load: type:%u, start:0x%lx head:0x%lx flags:0x%lx\n", + image->type, image->start, image->head, flags); /* * Free up any temporary buffers allocated which are not needed * after image has been loaded @@ -326,10 +459,12 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd, exchange: image = xchg(dest_image, image); out: +#ifdef CONFIG_CRASH_DUMP if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image) arch_kexec_protect_crashkres(); +#endif - mutex_unlock(&kexec_mutex); + kexec_unlock(); kimage_free(image); return ret; } @@ -341,11 +476,12 @@ static int locate_mem_hole_top_down(unsigned long start, unsigned long end, unsigned long temp_start, temp_end; temp_end = min(end, kbuf->buf_max); - temp_start = temp_end - kbuf->memsz; + temp_start = temp_end - kbuf->memsz + 1; + kexec_random_range_start(temp_start, temp_end, kbuf, &temp_start); do { /* align down start */ - temp_start = temp_start & (~(kbuf->buf_align - 1)); + temp_start = ALIGN_DOWN(temp_start, kbuf->buf_align); if (temp_start < start || temp_start < kbuf->buf_min) return 0; @@ -361,6 +497,12 @@ static int locate_mem_hole_top_down(unsigned long start, unsigned long end, continue; } + /* Make sure this does not conflict with exclude range */ + if (arch_check_excluded_range(image, temp_start, temp_end)) { + temp_start = temp_start - PAGE_SIZE; + continue; + } + /* We found a suitable memory range */ break; } while (1); @@ -380,6 +522,8 @@ static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end, temp_start = max(start, kbuf->buf_min); + kexec_random_range_start(temp_start, end, kbuf, &temp_start); + do { temp_start = ALIGN(temp_start, kbuf->buf_align); temp_end = temp_start + kbuf->memsz - 1; @@ -395,6 +539,12 @@ static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end, continue; } + /* Make sure this does not conflict with exclude range */ + if (arch_check_excluded_range(image, temp_start, temp_end)) { + temp_start = temp_start + PAGE_SIZE; + continue; + } + /* We found a suitable memory range */ break; } while (1); @@ -406,12 +556,18 @@ static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end, return 1; } -static int locate_mem_hole_callback(u64 start, u64 end, void *arg) +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 */ + + /* Don't use memory that will be detected and handled by a driver. */ + if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED) + return 0; + if (sz < kbuf->memsz) return 0; @@ -427,8 +583,67 @@ static int locate_mem_hole_callback(u64 start, u64 end, void *arg) 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 = { }; + +#ifdef CONFIG_CRASH_DUMP + if (kbuf->image->type == KEXEC_TYPE_CRASH) + return func(&crashk_res, kbuf); +#endif + + /* + * Using MEMBLOCK_NONE will properly skip MEMBLOCK_DRIVER_MANAGED. See + * IORESOURCE_SYSRAM_DRIVER_MANAGED handling in + * locate_mem_hole_callback(). + */ + 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 + /** - * arch_kexec_walk_mem - call func(data) on free memory regions + * 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. * @@ -436,18 +651,59 @@ static int locate_mem_hole_callback(u64 start, u64 end, void *arg) * and that value will be returned. If all free regions are visited without * func returning non-zero, then zero will be returned. */ -int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf, - int (*func)(u64, u64, void *)) +static int kexec_walk_resources(struct kexec_buf *kbuf, + int (*func)(struct resource *, void *)) { +#ifdef CONFIG_CRASH_DUMP 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); +#endif + if (kbuf->top_down) + return walk_system_ram_res_rev(0, ULONG_MAX, kbuf, func); else return walk_system_ram_res(0, ULONG_MAX, kbuf, func); } +static int kexec_alloc_contig(struct kexec_buf *kbuf) +{ + size_t nr_pages = kbuf->memsz >> PAGE_SHIFT; + unsigned long mem; + struct page *p; + + /* User space disabled CMA allocations, bail out. */ + if (kbuf->image->no_cma) + return -EPERM; + + /* Skip CMA logic for crash kernel */ + if (kbuf->image->type == KEXEC_TYPE_CRASH) + return -EPERM; + + p = dma_alloc_from_contiguous(NULL, nr_pages, get_order(kbuf->buf_align), true); + if (!p) + return -ENOMEM; + + pr_debug("allocated %zu DMA pages at 0x%lx", nr_pages, page_to_boot_pfn(p)); + + mem = page_to_boot_pfn(p) << PAGE_SHIFT; + + if (kimage_is_destination_range(kbuf->image, mem, mem + kbuf->memsz)) { + /* Our region is already in use by a statically defined one. Bail out. */ + pr_debug("CMA overlaps existing mem: 0x%lx+0x%lx\n", mem, kbuf->memsz); + dma_release_from_contiguous(NULL, p, nr_pages); + return -EBUSY; + } + + kbuf->mem = page_to_boot_pfn(p) << PAGE_SHIFT; + kbuf->cma = p; + + arch_kexec_post_alloc_pages(page_address(p), (int)nr_pages, 0); + + return 0; +} + /** * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel * @kbuf: Parameters for the memory search. @@ -460,7 +716,29 @@ int kexec_locate_mem_hole(struct kexec_buf *kbuf) { int ret; - ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback); + /* Arch knows where to place */ + if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN) + return 0; + + /* + * If KHO is active, only use KHO scratch memory. All other memory + * could potentially be handed over. + */ + ret = kho_locate_mem_hole(kbuf, locate_mem_hole_callback); + if (ret <= 0) + return ret; + + /* + * Try to find a free physically contiguous block of memory first. With that, we + * can avoid any copying at kexec time. + */ + if (!kexec_alloc_contig(kbuf)) + 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; } @@ -469,7 +747,7 @@ int kexec_locate_mem_hole(struct kexec_buf *kbuf) * kexec_add_buffer - place a buffer in a kexec segment * @kbuf: Buffer contents and memory parameters. * - * This function assumes that kexec_mutex is held. + * This function assumes that kexec_lock is held. * On successful return, @kbuf->mem will have the physical address of * the buffer in memory. * @@ -477,7 +755,6 @@ int kexec_locate_mem_hole(struct kexec_buf *kbuf) */ int kexec_add_buffer(struct kexec_buf *kbuf) { - struct kexec_segment *ksegment; int ret; @@ -503,9 +780,10 @@ int kexec_add_buffer(struct kexec_buf *kbuf) /* Ensure minimum alignment needed for segments. */ kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE); kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE); + kbuf->cma = NULL; /* Walk the RAM ranges and allocate a suitable range for the buffer */ - ret = kexec_locate_mem_hole(kbuf); + ret = arch_kexec_locate_mem_hole(kbuf); if (ret) return ret; @@ -515,6 +793,7 @@ int kexec_add_buffer(struct kexec_buf *kbuf) ksegment->bufsz = kbuf->bufsz; ksegment->mem = kbuf->mem; ksegment->memsz = kbuf->memsz; + kbuf->image->segment_cma[kbuf->image->nr_segments] = kbuf->cma; kbuf->image->nr_segments++; return 0; } @@ -522,52 +801,36 @@ int kexec_add_buffer(struct kexec_buf *kbuf) /* Calculate and store the digest of segments */ static int kexec_calculate_store_digests(struct kimage *image) { - struct crypto_shash *tfm; - struct shash_desc *desc; + struct sha256_ctx sctx; int ret = 0, i, j, zero_buf_sz, sha_region_sz; - size_t desc_size, nullsz; - char *digest; + size_t nullsz; + u8 digest[SHA256_DIGEST_SIZE]; void *zero_buf; struct kexec_sha_region *sha_regions; struct purgatory_info *pi = &image->purgatory_info; + if (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_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; - desc->flags = 0; - - ret = crypto_shash_init(desc); - if (ret < 0) - goto out_free_sha_regions; + return -ENOMEM; - digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); - if (!digest) { - ret = -ENOMEM; - goto out_free_sha_regions; - } + sha256_init(&sctx); for (j = i = 0; i < image->nr_segments; i++) { struct kexec_segment *ksegment; +#ifdef CONFIG_CRASH_HOTPLUG + /* Exclude elfcorehdr segment to allow future changes via hotplug */ + if (i == image->elfcorehdr_index) + continue; +#endif + ksegment = &image->segment[i]; /* * Skip purgatory as it will be modified once we put digest @@ -576,10 +839,14 @@ static int kexec_calculate_store_digests(struct kimage *image) if (ksegment->kbuf == pi->purgatory_buf) continue; - ret = crypto_shash_update(desc, ksegment->kbuf, - ksegment->bufsz); - if (ret) - break; + /* + * Skip the segment if ima_segment_index is set and matches + * the current index + */ + if (check_ima_segment_index(image, i)) + continue; + + sha256_update(&sctx, ksegment->kbuf, ksegment->bufsz); /* * Assume rest of the buffer is filled with zero and @@ -591,128 +858,52 @@ static int kexec_calculate_store_digests(struct kimage *image) if (bytes > zero_buf_sz) bytes = zero_buf_sz; - ret = crypto_shash_update(desc, zero_buf, bytes); - if (ret) - break; + sha256_update(&sctx, zero_buf, bytes); 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; + sha256_final(&sctx, digest); - ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest", - digest, SHA256_DIGEST_SIZE, 0); - 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_sha_regions; -out_free_digest: - kfree(digest); + ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest", + digest, SHA256_DIGEST_SIZE, 0); out_free_sha_regions: vfree(sha_regions); -out_free_desc: - kfree(desc); -out_free_tfm: - kfree(tfm); -out: return ret; } -/* Actually load purgatory. Lot of code taken from kexec-tools */ -static int __kexec_load_purgatory(struct kimage *image, unsigned long min, - unsigned long max, int top_down) +#ifdef CONFIG_ARCH_SUPPORTS_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) { - struct purgatory_info *pi = &image->purgatory_info; - unsigned long align, bss_align, bss_sz, bss_pad; - unsigned long entry, load_addr, curr_load_addr, bss_addr, offset; - unsigned char *buf_addr, *src; - int i, ret = 0, entry_sidx = -1; - const Elf_Shdr *sechdrs_c; - Elf_Shdr *sechdrs = NULL; - struct kexec_buf kbuf = { .image = image, .bufsz = 0, .buf_align = 1, - .buf_min = min, .buf_max = max, - .top_down = top_down }; - - /* - * sechdrs_c points to section headers in purgatory and are read - * only. No modifications allowed. - */ - sechdrs_c = (void *)pi->ehdr + pi->ehdr->e_shoff; - - /* - * We can not modify sechdrs_c[] and its fields. It is read only. - * Copy it over to a local copy where one can store some temporary - * data and free it at the end. We need to modify ->sh_addr and - * ->sh_offset fields to keep track of permanent and temporary - * locations of sections. - */ - sechdrs = vzalloc(pi->ehdr->e_shnum * sizeof(Elf_Shdr)); - if (!sechdrs) - return -ENOMEM; - - memcpy(sechdrs, sechdrs_c, pi->ehdr->e_shnum * sizeof(Elf_Shdr)); - - /* - * We seem to have multiple copies of sections. First copy is which - * is embedded in kernel in read only section. Some of these sections - * will be copied to a temporary buffer and relocated. And these - * sections will finally be copied to their final destination at - * segment load time. - * - * Use ->sh_offset to reflect section address in memory. It will - * point to original read only copy if section is not allocatable. - * Otherwise it will point to temporary copy which will be relocated. - * - * Use ->sh_addr to contain final address of the section where it - * will go during execution time. - */ - for (i = 0; i < pi->ehdr->e_shnum; i++) { - if (sechdrs[i].sh_type == SHT_NOBITS) - continue; - - sechdrs[i].sh_offset = (unsigned long)pi->ehdr + - sechdrs[i].sh_offset; - } - - /* - * Identify entry point section and make entry relative to section - * start. - */ - entry = pi->ehdr->e_entry; - for (i = 0; i < pi->ehdr->e_shnum; i++) { - if (!(sechdrs[i].sh_flags & SHF_ALLOC)) - continue; - - if (!(sechdrs[i].sh_flags & SHF_EXECINSTR)) - continue; - - /* Make entry section relative */ - if (sechdrs[i].sh_addr <= pi->ehdr->e_entry && - ((sechdrs[i].sh_addr + sechdrs[i].sh_size) > - pi->ehdr->e_entry)) { - entry_sidx = i; - entry -= sechdrs[i].sh_addr; - break; - } - } + const Elf_Shdr *sechdrs; + unsigned long bss_align; + unsigned long bss_sz; + unsigned long align; + int i, ret; - /* Determine how much memory is needed to load relocatable object. */ - bss_align = 1; - bss_sz = 0; + 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)) @@ -720,111 +911,137 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min, 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; + if (kbuf->buf_align < align) + kbuf->buf_align = align; + kbuf->bufsz = ALIGN(kbuf->bufsz, align); + kbuf->bufsz += sechdrs[i].sh_size; } else { - /* bss section */ 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; - /* Determine the bss padding required to align bss properly */ - bss_pad = 0; - if (kbuf.bufsz & (bss_align - 1)) - bss_pad = bss_align - (kbuf.bufsz & (bss_align - 1)); - - kbuf.memsz = kbuf.bufsz + bss_pad + bss_sz; + kbuf->buffer = vzalloc(kbuf->bufsz); + if (!kbuf->buffer) + return -ENOMEM; + pi->purgatory_buf = kbuf->buffer; - /* Allocate buffer for purgatory */ - kbuf.buffer = vzalloc(kbuf.bufsz); - if (!kbuf.buffer) { - ret = -ENOMEM; + ret = kexec_add_buffer(kbuf); + if (ret) goto out; - } - if (kbuf.buf_align < bss_align) - kbuf.buf_align = bss_align; + return 0; +out: + vfree(pi->purgatory_buf); + pi->purgatory_buf = NULL; + return ret; +} - /* Add buffer to segment list */ - ret = kexec_add_buffer(&kbuf); - if (ret) - goto out; - pi->purgatory_load_addr = kbuf.mem; +/* + * 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; + size_t sechdrs_size; + 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_size = array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum); + sechdrs = vzalloc(sechdrs_size); + if (!sechdrs) + return -ENOMEM; + memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff, sechdrs_size); + pi->sechdrs = sechdrs; - /* Load SHF_ALLOC sections */ - buf_addr = kbuf.buffer; - load_addr = curr_load_addr = pi->purgatory_load_addr; - bss_addr = load_addr + kbuf.bufsz + bss_pad; + 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) { - curr_load_addr = ALIGN(curr_load_addr, align); - offset = curr_load_addr - load_addr; - /* We already modifed ->sh_offset to keep src addr */ - src = (char *) sechdrs[i].sh_offset; - memcpy(buf_addr + offset, src, sechdrs[i].sh_size); - - /* Store load address and source address of section */ - sechdrs[i].sh_addr = curr_load_addr; - - /* - * This section got copied to temporary buffer. Update - * ->sh_offset accordingly. - */ - sechdrs[i].sh_offset = (unsigned long)(buf_addr + offset); - - /* Advance to the next address */ - curr_load_addr += sechdrs[i].sh_size; - } else { + 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; } - } - /* Update entry point based on load address of text section */ - if (entry_sidx >= 0) - entry += sechdrs[entry_sidx].sh_addr; + offset = ALIGN(offset, align); - /* Make kernel jump to purgatory after shutdown */ - image->start = entry; + /* + * Check if the segment contains the entry point, if so, + * calculate the value of image->start based on it. + * If the compiler has produced more than one .text section + * (Eg: .text.hot), they are generally after the main .text + * section, and they shall not be used to calculate + * image->start. So do not re-calculate image->start if it + * is not set to the initial value, and warn the user so they + * have a chance to fix their purgatory's linker script. + */ + 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) && + !WARN_ON(kbuf->image->start != pi->ehdr->e_entry)) { + kbuf->image->start -= sechdrs[i].sh_addr; + kbuf->image->start += kbuf->mem + offset; + } - /* Used later to get/set symbol values */ - pi->sechdrs = sechdrs; + src = (void *)pi->ehdr + sechdrs[i].sh_offset; + dst = pi->purgatory_buf + offset; + memcpy(dst, src, sechdrs[i].sh_size); - /* - * Used later to identify which section is purgatory and skip it - * from checksumming. - */ - pi->purgatory_buf = kbuf.buffer; - return ret; -out: - vfree(sechdrs); - vfree(kbuf.buffer); - return ret; + 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; - Elf_Shdr *sechdrs = pi->sechdrs; + const Elf_Shdr *sechdrs; + + sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff; - /* Apply relocations */ for (i = 0; i < pi->ehdr->e_shnum; i++) { - Elf_Shdr *section, *symtab; + const Elf_Shdr *relsec; + const Elf_Shdr *symtab; + Elf_Shdr *section; + + relsec = sechdrs + i; - if (sechdrs[i].sh_type != SHT_RELA && - sechdrs[i].sh_type != SHT_REL) + if (relsec->sh_type != SHT_RELA && + relsec->sh_type != SHT_REL) continue; /* @@ -833,12 +1050,12 @@ static int kexec_apply_relocations(struct kimage *image) * symbol table. And ->sh_info contains section header * index of section to which relocations apply. */ - if (sechdrs[i].sh_info >= pi->ehdr->e_shnum || - sechdrs[i].sh_link >= pi->ehdr->e_shnum) + if (relsec->sh_info >= pi->ehdr->e_shnum || + relsec->sh_link >= pi->ehdr->e_shnum) return -ENOEXEC; - section = &sechdrs[sechdrs[i].sh_info]; - symtab = &sechdrs[sechdrs[i].sh_link]; + section = pi->sechdrs + relsec->sh_info; + symtab = sechdrs + relsec->sh_link; if (!(section->sh_flags & SHF_ALLOC)) continue; @@ -855,12 +1072,12 @@ static int kexec_apply_relocations(struct kimage *image) * Respective architecture needs to provide support for applying * relocations of type SHT_RELA/SHT_REL. */ - if (sechdrs[i].sh_type == SHT_RELA) - ret = arch_kexec_apply_relocations_add(pi->ehdr, - sechdrs, i); - else if (sechdrs[i].sh_type == SHT_REL) - ret = arch_kexec_apply_relocations(pi->ehdr, - sechdrs, i); + 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; } @@ -868,10 +1085,18 @@ static int kexec_apply_relocations(struct kimage *image) return 0; } -/* Load relocatable purgatory object and relocate it appropriately */ -int kexec_load_purgatory(struct kimage *image, unsigned long min, - unsigned long max, int top_down, - unsigned long *load_addr) +/* + * 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; @@ -879,55 +1104,51 @@ int kexec_load_purgatory(struct kimage *image, unsigned long min, if (kexec_purgatory_size <= 0) return -EINVAL; - if (kexec_purgatory_size < sizeof(Elf_Ehdr)) - return -ENOEXEC; + pi->ehdr = (const Elf_Ehdr *)kexec_purgatory; - pi->ehdr = (Elf_Ehdr *)kexec_purgatory; - - if (memcmp(pi->ehdr->e_ident, ELFMAG, SELFMAG) != 0 - || pi->ehdr->e_type != ET_REL - || !elf_check_arch(pi->ehdr) - || pi->ehdr->e_shentsize != sizeof(Elf_Shdr)) - return -ENOEXEC; - - if (pi->ehdr->e_shoff >= kexec_purgatory_size - || (pi->ehdr->e_shnum * sizeof(Elf_Shdr) > - kexec_purgatory_size - pi->ehdr->e_shoff)) - return -ENOEXEC; - - ret = __kexec_load_purgatory(image, min, max, top_down); + 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; - *load_addr = pi->purgatory_load_addr; return 0; out: vfree(pi->sechdrs); pi->sechdrs = NULL; - +out_free_kbuf: vfree(pi->purgatory_buf); pi->purgatory_buf = NULL; return ret; } -static Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi, - const char *name) +/* + * 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) { - Elf_Sym *syms; - Elf_Shdr *sechdrs; - Elf_Ehdr *ehdr; - int i, k; + const Elf_Shdr *sechdrs; + const Elf_Ehdr *ehdr; + const Elf_Sym *syms; const char *strtab; + int i, k; - if (!pi->sechdrs || !pi->ehdr) + if (!pi->ehdr) return NULL; - sechdrs = pi->sechdrs; ehdr = pi->ehdr; + sechdrs = (void *)ehdr + ehdr->e_shoff; for (i = 0; i < ehdr->e_shnum; i++) { if (sechdrs[i].sh_type != SHT_SYMTAB) @@ -936,8 +1157,8 @@ static Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi, if (sechdrs[i].sh_link >= ehdr->e_shnum) /* Invalid strtab section number */ continue; - strtab = (char *)sechdrs[sechdrs[i].sh_link].sh_offset; - syms = (Elf_Sym *)sechdrs[i].sh_offset; + 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++) { @@ -965,7 +1186,7 @@ static Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi, void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name) { struct purgatory_info *pi = &image->purgatory_info; - Elf_Sym *sym; + const Elf_Sym *sym; Elf_Shdr *sechdr; sym = kexec_purgatory_find_symbol(pi, name); @@ -988,9 +1209,9 @@ void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name) int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name, void *buf, unsigned int size, bool get_value) { - Elf_Sym *sym; - Elf_Shdr *sechdrs; struct purgatory_info *pi = &image->purgatory_info; + const Elf_Sym *sym; + Elf_Shdr *sec; char *sym_buf; sym = kexec_purgatory_find_symbol(pi, name); @@ -1003,16 +1224,15 @@ int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name, return -EINVAL; } - sechdrs = pi->sechdrs; + sec = pi->sechdrs + sym->st_shndx; - if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) { + 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 = (unsigned char *)sechdrs[sym->st_shndx].sh_offset + - sym->st_value; + sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value; if (get_value) memcpy((void *)buf, sym_buf, size); @@ -1021,3 +1241,4 @@ int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name, return 0; } +#endif /* CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY */ |