1 // SPDX-License-Identifier: GPL-2.0-only
3 * kexec: kexec_file_load system call
5 * Copyright (C) 2014 Red Hat Inc.
7 * Vivek Goyal <vgoyal@redhat.com>
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/capability.h>
14 #include <linux/file.h>
15 #include <linux/slab.h>
16 #include <linux/kexec.h>
17 #include <linux/memblock.h>
18 #include <linux/mutex.h>
19 #include <linux/list.h>
21 #include <linux/ima.h>
22 #include <crypto/hash.h>
23 #include <crypto/sha.h>
24 #include <linux/elf.h>
25 #include <linux/elfcore.h>
26 #include <linux/kernel.h>
27 #include <linux/kernel_read_file.h>
28 #include <linux/syscalls.h>
29 #include <linux/vmalloc.h>
30 #include "kexec_internal.h"
32 #ifdef CONFIG_KEXEC_SIG
33 static bool sig_enforce = IS_ENABLED(CONFIG_KEXEC_SIG_FORCE);
35 void set_kexec_sig_enforced(void)
41 static int kexec_calculate_store_digests(struct kimage *image);
44 * Currently this is the only default function that is exported as some
45 * architectures need it to do additional handlings.
46 * In the future, other default functions may be exported too if required.
48 int kexec_image_probe_default(struct kimage *image, void *buf,
49 unsigned long buf_len)
51 const struct kexec_file_ops * const *fops;
54 for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) {
55 ret = (*fops)->probe(buf, buf_len);
65 /* Architectures can provide this probe function */
66 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
67 unsigned long buf_len)
69 return kexec_image_probe_default(image, buf, buf_len);
72 static void *kexec_image_load_default(struct kimage *image)
74 if (!image->fops || !image->fops->load)
75 return ERR_PTR(-ENOEXEC);
77 return image->fops->load(image, image->kernel_buf,
78 image->kernel_buf_len, image->initrd_buf,
79 image->initrd_buf_len, image->cmdline_buf,
80 image->cmdline_buf_len);
83 void * __weak arch_kexec_kernel_image_load(struct kimage *image)
85 return kexec_image_load_default(image);
88 int kexec_image_post_load_cleanup_default(struct kimage *image)
90 if (!image->fops || !image->fops->cleanup)
93 return image->fops->cleanup(image->image_loader_data);
96 int __weak arch_kimage_file_post_load_cleanup(struct kimage *image)
98 return kexec_image_post_load_cleanup_default(image);
101 #ifdef CONFIG_KEXEC_SIG
102 static int kexec_image_verify_sig_default(struct kimage *image, void *buf,
103 unsigned long buf_len)
105 if (!image->fops || !image->fops->verify_sig) {
106 pr_debug("kernel loader does not support signature verification.\n");
107 return -EKEYREJECTED;
110 return image->fops->verify_sig(buf, buf_len);
113 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
114 unsigned long buf_len)
116 return kexec_image_verify_sig_default(image, buf, buf_len);
121 * Free up memory used by kernel, initrd, and command line. This is temporary
122 * memory allocation which is not needed any more after these buffers have
123 * been loaded into separate segments and have been copied elsewhere.
125 void kimage_file_post_load_cleanup(struct kimage *image)
127 struct purgatory_info *pi = &image->purgatory_info;
129 vfree(image->kernel_buf);
130 image->kernel_buf = NULL;
132 vfree(image->initrd_buf);
133 image->initrd_buf = NULL;
135 kfree(image->cmdline_buf);
136 image->cmdline_buf = NULL;
138 vfree(pi->purgatory_buf);
139 pi->purgatory_buf = NULL;
144 #ifdef CONFIG_IMA_KEXEC
145 vfree(image->ima_buffer);
146 image->ima_buffer = NULL;
147 #endif /* CONFIG_IMA_KEXEC */
149 /* See if architecture has anything to cleanup post load */
150 arch_kimage_file_post_load_cleanup(image);
153 * Above call should have called into bootloader to free up
154 * any data stored in kimage->image_loader_data. It should
155 * be ok now to free it up.
157 kfree(image->image_loader_data);
158 image->image_loader_data = NULL;
161 #ifdef CONFIG_KEXEC_SIG
163 kimage_validate_signature(struct kimage *image)
167 ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf,
168 image->kernel_buf_len);
172 pr_notice("Enforced kernel signature verification failed (%d).\n", ret);
177 * If IMA is guaranteed to appraise a signature on the kexec
178 * image, permit it even if the kernel is otherwise locked
181 if (!ima_appraise_signature(READING_KEXEC_IMAGE) &&
182 security_locked_down(LOCKDOWN_KEXEC))
185 pr_debug("kernel signature verification failed (%d).\n", ret);
193 * In file mode list of segments is prepared by kernel. Copy relevant
194 * data from user space, do error checking, prepare segment list
197 kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
198 const char __user *cmdline_ptr,
199 unsigned long cmdline_len, unsigned flags)
204 ret = kernel_read_file_from_fd(kernel_fd, 0, &image->kernel_buf,
205 INT_MAX, NULL, READING_KEXEC_IMAGE);
208 image->kernel_buf_len = ret;
210 /* Call arch image probe handlers */
211 ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
212 image->kernel_buf_len);
216 #ifdef CONFIG_KEXEC_SIG
217 ret = kimage_validate_signature(image);
222 /* It is possible that there no initramfs is being loaded */
223 if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
224 ret = kernel_read_file_from_fd(initrd_fd, 0, &image->initrd_buf,
226 READING_KEXEC_INITRAMFS);
229 image->initrd_buf_len = ret;
234 image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len);
235 if (IS_ERR(image->cmdline_buf)) {
236 ret = PTR_ERR(image->cmdline_buf);
237 image->cmdline_buf = NULL;
241 image->cmdline_buf_len = cmdline_len;
243 /* command line should be a string with last byte null */
244 if (image->cmdline_buf[cmdline_len - 1] != '\0') {
249 ima_kexec_cmdline(kernel_fd, image->cmdline_buf,
250 image->cmdline_buf_len - 1);
253 /* IMA needs to pass the measurement list to the next kernel. */
254 ima_add_kexec_buffer(image);
256 /* Call arch image load handlers */
257 ldata = arch_kexec_kernel_image_load(image);
260 ret = PTR_ERR(ldata);
264 image->image_loader_data = ldata;
266 /* In case of error, free up all allocated memory in this function */
268 kimage_file_post_load_cleanup(image);
273 kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
274 int initrd_fd, const char __user *cmdline_ptr,
275 unsigned long cmdline_len, unsigned long flags)
278 struct kimage *image;
279 bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
281 image = do_kimage_alloc_init();
285 image->file_mode = 1;
287 if (kexec_on_panic) {
288 /* Enable special crash kernel control page alloc policy. */
289 image->control_page = crashk_res.start;
290 image->type = KEXEC_TYPE_CRASH;
293 ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
294 cmdline_ptr, cmdline_len, flags);
298 ret = sanity_check_segment_list(image);
300 goto out_free_post_load_bufs;
303 image->control_code_page = kimage_alloc_control_pages(image,
304 get_order(KEXEC_CONTROL_PAGE_SIZE));
305 if (!image->control_code_page) {
306 pr_err("Could not allocate control_code_buffer\n");
307 goto out_free_post_load_bufs;
310 if (!kexec_on_panic) {
311 image->swap_page = kimage_alloc_control_pages(image, 0);
312 if (!image->swap_page) {
313 pr_err("Could not allocate swap buffer\n");
314 goto out_free_control_pages;
320 out_free_control_pages:
321 kimage_free_page_list(&image->control_pages);
322 out_free_post_load_bufs:
323 kimage_file_post_load_cleanup(image);
329 SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
330 unsigned long, cmdline_len, const char __user *, cmdline_ptr,
331 unsigned long, flags)
334 struct kimage **dest_image, *image;
336 /* We only trust the superuser with rebooting the system. */
337 if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
340 /* Make sure we have a legal set of flags */
341 if (flags != (flags & KEXEC_FILE_FLAGS))
346 if (!kexec_trylock())
349 dest_image = &kexec_image;
350 if (flags & KEXEC_FILE_ON_CRASH) {
351 dest_image = &kexec_crash_image;
352 if (kexec_crash_image)
353 arch_kexec_unprotect_crashkres();
356 if (flags & KEXEC_FILE_UNLOAD)
360 * In case of crash, new kernel gets loaded in reserved region. It is
361 * same memory where old crash kernel might be loaded. Free any
362 * current crash dump kernel before we corrupt it.
364 if (flags & KEXEC_FILE_ON_CRASH)
365 kimage_free(xchg(&kexec_crash_image, NULL));
367 ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr,
372 ret = machine_kexec_prepare(image);
377 * Some architecture(like S390) may touch the crash memory before
378 * machine_kexec_prepare(), we must copy vmcoreinfo data after it.
380 ret = kimage_crash_copy_vmcoreinfo(image);
384 ret = kexec_calculate_store_digests(image);
388 for (i = 0; i < image->nr_segments; i++) {
389 struct kexec_segment *ksegment;
391 ksegment = &image->segment[i];
392 pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
393 i, ksegment->buf, ksegment->bufsz, ksegment->mem,
396 ret = kimage_load_segment(image, &image->segment[i]);
401 kimage_terminate(image);
403 ret = machine_kexec_post_load(image);
408 * Free up any temporary buffers allocated which are not needed
409 * after image has been loaded
411 kimage_file_post_load_cleanup(image);
413 image = xchg(dest_image, image);
415 if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image)
416 arch_kexec_protect_crashkres();
423 static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
424 struct kexec_buf *kbuf)
426 struct kimage *image = kbuf->image;
427 unsigned long temp_start, temp_end;
429 temp_end = min(end, kbuf->buf_max);
430 temp_start = temp_end - kbuf->memsz;
433 /* align down start */
434 temp_start = temp_start & (~(kbuf->buf_align - 1));
436 if (temp_start < start || temp_start < kbuf->buf_min)
439 temp_end = temp_start + kbuf->memsz - 1;
442 * Make sure this does not conflict with any of existing
445 if (kimage_is_destination_range(image, temp_start, temp_end)) {
446 temp_start = temp_start - PAGE_SIZE;
450 /* We found a suitable memory range */
454 /* If we are here, we found a suitable memory range */
455 kbuf->mem = temp_start;
457 /* Success, stop navigating through remaining System RAM ranges */
461 static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
462 struct kexec_buf *kbuf)
464 struct kimage *image = kbuf->image;
465 unsigned long temp_start, temp_end;
467 temp_start = max(start, kbuf->buf_min);
470 temp_start = ALIGN(temp_start, kbuf->buf_align);
471 temp_end = temp_start + kbuf->memsz - 1;
473 if (temp_end > end || temp_end > kbuf->buf_max)
476 * Make sure this does not conflict with any of existing
479 if (kimage_is_destination_range(image, temp_start, temp_end)) {
480 temp_start = temp_start + PAGE_SIZE;
484 /* We found a suitable memory range */
488 /* If we are here, we found a suitable memory range */
489 kbuf->mem = temp_start;
491 /* Success, stop navigating through remaining System RAM ranges */
495 static int locate_mem_hole_callback(struct resource *res, void *arg)
497 struct kexec_buf *kbuf = (struct kexec_buf *)arg;
498 u64 start = res->start, end = res->end;
499 unsigned long sz = end - start + 1;
501 /* Returning 0 will take to next memory range */
503 /* Don't use memory that will be detected and handled by a driver. */
504 if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED)
507 if (sz < kbuf->memsz)
510 if (end < kbuf->buf_min || start > kbuf->buf_max)
514 * Allocate memory top down with-in ram range. Otherwise bottom up
518 return locate_mem_hole_top_down(start, end, kbuf);
519 return locate_mem_hole_bottom_up(start, end, kbuf);
522 #ifdef CONFIG_ARCH_KEEP_MEMBLOCK
523 static int kexec_walk_memblock(struct kexec_buf *kbuf,
524 int (*func)(struct resource *, void *))
528 phys_addr_t mstart, mend;
529 struct resource res = { };
531 if (kbuf->image->type == KEXEC_TYPE_CRASH)
532 return func(&crashk_res, kbuf);
534 if (kbuf->top_down) {
535 for_each_free_mem_range_reverse(i, NUMA_NO_NODE, MEMBLOCK_NONE,
536 &mstart, &mend, NULL) {
538 * In memblock, end points to the first byte after the
539 * range while in kexec, end points to the last byte
544 ret = func(&res, kbuf);
549 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
550 &mstart, &mend, NULL) {
552 * In memblock, end points to the first byte after the
553 * range while in kexec, end points to the last byte
558 ret = func(&res, kbuf);
567 static int kexec_walk_memblock(struct kexec_buf *kbuf,
568 int (*func)(struct resource *, void *))
575 * kexec_walk_resources - call func(data) on free memory regions
576 * @kbuf: Context info for the search. Also passed to @func.
577 * @func: Function to call for each memory region.
579 * Return: The memory walk will stop when func returns a non-zero value
580 * and that value will be returned. If all free regions are visited without
581 * func returning non-zero, then zero will be returned.
583 static int kexec_walk_resources(struct kexec_buf *kbuf,
584 int (*func)(struct resource *, void *))
586 if (kbuf->image->type == KEXEC_TYPE_CRASH)
587 return walk_iomem_res_desc(crashk_res.desc,
588 IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
589 crashk_res.start, crashk_res.end,
592 return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
596 * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
597 * @kbuf: Parameters for the memory search.
599 * On success, kbuf->mem will have the start address of the memory region found.
601 * Return: 0 on success, negative errno on error.
603 int kexec_locate_mem_hole(struct kexec_buf *kbuf)
607 /* Arch knows where to place */
608 if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN)
611 if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
612 ret = kexec_walk_resources(kbuf, locate_mem_hole_callback);
614 ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback);
616 return ret == 1 ? 0 : -EADDRNOTAVAIL;
620 * arch_kexec_locate_mem_hole - Find free memory to place the segments.
621 * @kbuf: Parameters for the memory search.
623 * On success, kbuf->mem will have the start address of the memory region found.
625 * Return: 0 on success, negative errno on error.
627 int __weak arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
629 return kexec_locate_mem_hole(kbuf);
633 * kexec_add_buffer - place a buffer in a kexec segment
634 * @kbuf: Buffer contents and memory parameters.
636 * This function assumes that kexec_mutex is held.
637 * On successful return, @kbuf->mem will have the physical address of
638 * the buffer in memory.
640 * Return: 0 on success, negative errno on error.
642 int kexec_add_buffer(struct kexec_buf *kbuf)
644 struct kexec_segment *ksegment;
647 /* Currently adding segment this way is allowed only in file mode */
648 if (!kbuf->image->file_mode)
651 if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX)
655 * Make sure we are not trying to add buffer after allocating
656 * control pages. All segments need to be placed first before
657 * any control pages are allocated. As control page allocation
658 * logic goes through list of segments to make sure there are
659 * no destination overlaps.
661 if (!list_empty(&kbuf->image->control_pages)) {
666 /* Ensure minimum alignment needed for segments. */
667 kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
668 kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
670 /* Walk the RAM ranges and allocate a suitable range for the buffer */
671 ret = arch_kexec_locate_mem_hole(kbuf);
675 /* Found a suitable memory range */
676 ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
677 ksegment->kbuf = kbuf->buffer;
678 ksegment->bufsz = kbuf->bufsz;
679 ksegment->mem = kbuf->mem;
680 ksegment->memsz = kbuf->memsz;
681 kbuf->image->nr_segments++;
685 /* Calculate and store the digest of segments */
686 static int kexec_calculate_store_digests(struct kimage *image)
688 struct crypto_shash *tfm;
689 struct shash_desc *desc;
690 int ret = 0, i, j, zero_buf_sz, sha_region_sz;
691 size_t desc_size, nullsz;
694 struct kexec_sha_region *sha_regions;
695 struct purgatory_info *pi = &image->purgatory_info;
697 if (!IS_ENABLED(CONFIG_ARCH_HAS_KEXEC_PURGATORY))
700 zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
701 zero_buf_sz = PAGE_SIZE;
703 tfm = crypto_alloc_shash("sha256", 0, 0);
709 desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
710 desc = kzalloc(desc_size, GFP_KERNEL);
716 sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region);
717 sha_regions = vzalloc(sha_region_sz);
725 ret = crypto_shash_init(desc);
727 goto out_free_sha_regions;
729 digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
732 goto out_free_sha_regions;
735 for (j = i = 0; i < image->nr_segments; i++) {
736 struct kexec_segment *ksegment;
738 ksegment = &image->segment[i];
740 * Skip purgatory as it will be modified once we put digest
743 if (ksegment->kbuf == pi->purgatory_buf)
746 ret = crypto_shash_update(desc, ksegment->kbuf,
752 * Assume rest of the buffer is filled with zero and
753 * update digest accordingly.
755 nullsz = ksegment->memsz - ksegment->bufsz;
757 unsigned long bytes = nullsz;
759 if (bytes > zero_buf_sz)
761 ret = crypto_shash_update(desc, zero_buf, bytes);
770 sha_regions[j].start = ksegment->mem;
771 sha_regions[j].len = ksegment->memsz;
776 ret = crypto_shash_final(desc, digest);
778 goto out_free_digest;
779 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha_regions",
780 sha_regions, sha_region_sz, 0);
782 goto out_free_digest;
784 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest",
785 digest, SHA256_DIGEST_SIZE, 0);
787 goto out_free_digest;
792 out_free_sha_regions:
802 #ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY
804 * kexec_purgatory_setup_kbuf - prepare buffer to load purgatory.
805 * @pi: Purgatory to be loaded.
806 * @kbuf: Buffer to setup.
808 * Allocates the memory needed for the buffer. Caller is responsible to free
809 * the memory after use.
811 * Return: 0 on success, negative errno on error.
813 static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi,
814 struct kexec_buf *kbuf)
816 const Elf_Shdr *sechdrs;
817 unsigned long bss_align;
818 unsigned long bss_sz;
822 sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
823 kbuf->buf_align = bss_align = 1;
824 kbuf->bufsz = bss_sz = 0;
826 for (i = 0; i < pi->ehdr->e_shnum; i++) {
827 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
830 align = sechdrs[i].sh_addralign;
831 if (sechdrs[i].sh_type != SHT_NOBITS) {
832 if (kbuf->buf_align < align)
833 kbuf->buf_align = align;
834 kbuf->bufsz = ALIGN(kbuf->bufsz, align);
835 kbuf->bufsz += sechdrs[i].sh_size;
837 if (bss_align < align)
839 bss_sz = ALIGN(bss_sz, align);
840 bss_sz += sechdrs[i].sh_size;
843 kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align);
844 kbuf->memsz = kbuf->bufsz + bss_sz;
845 if (kbuf->buf_align < bss_align)
846 kbuf->buf_align = bss_align;
848 kbuf->buffer = vzalloc(kbuf->bufsz);
851 pi->purgatory_buf = kbuf->buffer;
853 ret = kexec_add_buffer(kbuf);
859 vfree(pi->purgatory_buf);
860 pi->purgatory_buf = NULL;
865 * kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer.
866 * @pi: Purgatory to be loaded.
867 * @kbuf: Buffer prepared to store purgatory.
869 * Allocates the memory needed for the buffer. Caller is responsible to free
870 * the memory after use.
872 * Return: 0 on success, negative errno on error.
874 static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
875 struct kexec_buf *kbuf)
877 unsigned long bss_addr;
878 unsigned long offset;
883 * The section headers in kexec_purgatory are read-only. In order to
884 * have them modifiable make a temporary copy.
886 sechdrs = vzalloc(array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum));
889 memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff,
890 pi->ehdr->e_shnum * sizeof(Elf_Shdr));
891 pi->sechdrs = sechdrs;
894 bss_addr = kbuf->mem + kbuf->bufsz;
895 kbuf->image->start = pi->ehdr->e_entry;
897 for (i = 0; i < pi->ehdr->e_shnum; i++) {
901 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
904 align = sechdrs[i].sh_addralign;
905 if (sechdrs[i].sh_type == SHT_NOBITS) {
906 bss_addr = ALIGN(bss_addr, align);
907 sechdrs[i].sh_addr = bss_addr;
908 bss_addr += sechdrs[i].sh_size;
912 offset = ALIGN(offset, align);
915 * Check if the segment contains the entry point, if so,
916 * calculate the value of image->start based on it.
917 * If the compiler has produced more than one .text section
918 * (Eg: .text.hot), they are generally after the main .text
919 * section, and they shall not be used to calculate
920 * image->start. So do not re-calculate image->start if it
921 * is not set to the initial value, and warn the user so they
922 * have a chance to fix their purgatory's linker script.
924 if (sechdrs[i].sh_flags & SHF_EXECINSTR &&
925 pi->ehdr->e_entry >= sechdrs[i].sh_addr &&
926 pi->ehdr->e_entry < (sechdrs[i].sh_addr
927 + sechdrs[i].sh_size) &&
928 !WARN_ON(kbuf->image->start != pi->ehdr->e_entry)) {
929 kbuf->image->start -= sechdrs[i].sh_addr;
930 kbuf->image->start += kbuf->mem + offset;
933 src = (void *)pi->ehdr + sechdrs[i].sh_offset;
934 dst = pi->purgatory_buf + offset;
935 memcpy(dst, src, sechdrs[i].sh_size);
937 sechdrs[i].sh_addr = kbuf->mem + offset;
938 sechdrs[i].sh_offset = offset;
939 offset += sechdrs[i].sh_size;
945 static int kexec_apply_relocations(struct kimage *image)
948 struct purgatory_info *pi = &image->purgatory_info;
949 const Elf_Shdr *sechdrs;
951 sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
953 for (i = 0; i < pi->ehdr->e_shnum; i++) {
954 const Elf_Shdr *relsec;
955 const Elf_Shdr *symtab;
958 relsec = sechdrs + i;
960 if (relsec->sh_type != SHT_RELA &&
961 relsec->sh_type != SHT_REL)
965 * For section of type SHT_RELA/SHT_REL,
966 * ->sh_link contains section header index of associated
967 * symbol table. And ->sh_info contains section header
968 * index of section to which relocations apply.
970 if (relsec->sh_info >= pi->ehdr->e_shnum ||
971 relsec->sh_link >= pi->ehdr->e_shnum)
974 section = pi->sechdrs + relsec->sh_info;
975 symtab = sechdrs + relsec->sh_link;
977 if (!(section->sh_flags & SHF_ALLOC))
981 * symtab->sh_link contain section header index of associated
984 if (symtab->sh_link >= pi->ehdr->e_shnum)
985 /* Invalid section number? */
989 * Respective architecture needs to provide support for applying
990 * relocations of type SHT_RELA/SHT_REL.
992 if (relsec->sh_type == SHT_RELA)
993 ret = arch_kexec_apply_relocations_add(pi, section,
995 else if (relsec->sh_type == SHT_REL)
996 ret = arch_kexec_apply_relocations(pi, section,
1006 * kexec_load_purgatory - Load and relocate the purgatory object.
1007 * @image: Image to add the purgatory to.
1008 * @kbuf: Memory parameters to use.
1010 * Allocates the memory needed for image->purgatory_info.sechdrs and
1011 * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible
1012 * to free the memory after use.
1014 * Return: 0 on success, negative errno on error.
1016 int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf)
1018 struct purgatory_info *pi = &image->purgatory_info;
1021 if (kexec_purgatory_size <= 0)
1024 pi->ehdr = (const Elf_Ehdr *)kexec_purgatory;
1026 ret = kexec_purgatory_setup_kbuf(pi, kbuf);
1030 ret = kexec_purgatory_setup_sechdrs(pi, kbuf);
1034 ret = kexec_apply_relocations(image);
1043 vfree(pi->purgatory_buf);
1044 pi->purgatory_buf = NULL;
1049 * kexec_purgatory_find_symbol - find a symbol in the purgatory
1050 * @pi: Purgatory to search in.
1051 * @name: Name of the symbol.
1053 * Return: pointer to symbol in read-only symtab on success, NULL on error.
1055 static const Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
1058 const Elf_Shdr *sechdrs;
1059 const Elf_Ehdr *ehdr;
1060 const Elf_Sym *syms;
1068 sechdrs = (void *)ehdr + ehdr->e_shoff;
1070 for (i = 0; i < ehdr->e_shnum; i++) {
1071 if (sechdrs[i].sh_type != SHT_SYMTAB)
1074 if (sechdrs[i].sh_link >= ehdr->e_shnum)
1075 /* Invalid strtab section number */
1077 strtab = (void *)ehdr + sechdrs[sechdrs[i].sh_link].sh_offset;
1078 syms = (void *)ehdr + sechdrs[i].sh_offset;
1080 /* Go through symbols for a match */
1081 for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
1082 if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
1085 if (strcmp(strtab + syms[k].st_name, name) != 0)
1088 if (syms[k].st_shndx == SHN_UNDEF ||
1089 syms[k].st_shndx >= ehdr->e_shnum) {
1090 pr_debug("Symbol: %s has bad section index %d.\n",
1091 name, syms[k].st_shndx);
1095 /* Found the symbol we are looking for */
1103 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
1105 struct purgatory_info *pi = &image->purgatory_info;
1109 sym = kexec_purgatory_find_symbol(pi, name);
1111 return ERR_PTR(-EINVAL);
1113 sechdr = &pi->sechdrs[sym->st_shndx];
1116 * Returns the address where symbol will finally be loaded after
1117 * kexec_load_segment()
1119 return (void *)(sechdr->sh_addr + sym->st_value);
1123 * Get or set value of a symbol. If "get_value" is true, symbol value is
1124 * returned in buf otherwise symbol value is set based on value in buf.
1126 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
1127 void *buf, unsigned int size, bool get_value)
1129 struct purgatory_info *pi = &image->purgatory_info;
1134 sym = kexec_purgatory_find_symbol(pi, name);
1138 if (sym->st_size != size) {
1139 pr_err("symbol %s size mismatch: expected %lu actual %u\n",
1140 name, (unsigned long)sym->st_size, size);
1144 sec = pi->sechdrs + sym->st_shndx;
1146 if (sec->sh_type == SHT_NOBITS) {
1147 pr_err("symbol %s is in a bss section. Cannot %s\n", name,
1148 get_value ? "get" : "set");
1152 sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value;
1155 memcpy((void *)buf, sym_buf, size);
1157 memcpy((void *)sym_buf, buf, size);
1161 #endif /* CONFIG_ARCH_HAS_KEXEC_PURGATORY */
1163 int crash_exclude_mem_range(struct crash_mem *mem,
1164 unsigned long long mstart, unsigned long long mend)
1167 unsigned long long start, end, p_start, p_end;
1168 struct crash_mem_range temp_range = {0, 0};
1170 for (i = 0; i < mem->nr_ranges; i++) {
1171 start = mem->ranges[i].start;
1172 end = mem->ranges[i].end;
1176 if (mstart > end || mend < start)
1179 /* Truncate any area outside of range */
1185 /* Found completely overlapping range */
1186 if (p_start == start && p_end == end) {
1187 mem->ranges[i].start = 0;
1188 mem->ranges[i].end = 0;
1189 if (i < mem->nr_ranges - 1) {
1190 /* Shift rest of the ranges to left */
1191 for (j = i; j < mem->nr_ranges - 1; j++) {
1192 mem->ranges[j].start =
1193 mem->ranges[j+1].start;
1194 mem->ranges[j].end =
1195 mem->ranges[j+1].end;
1199 * Continue to check if there are another overlapping ranges
1200 * from the current position because of shifting the above
1211 if (p_start > start && p_end < end) {
1212 /* Split original range */
1213 mem->ranges[i].end = p_start - 1;
1214 temp_range.start = p_end + 1;
1215 temp_range.end = end;
1216 } else if (p_start != start)
1217 mem->ranges[i].end = p_start - 1;
1219 mem->ranges[i].start = p_end + 1;
1223 /* If a split happened, add the split to array */
1224 if (!temp_range.end)
1227 /* Split happened */
1228 if (i == mem->max_nr_ranges - 1)
1231 /* Location where new range should go */
1233 if (j < mem->nr_ranges) {
1234 /* Move over all ranges one slot towards the end */
1235 for (i = mem->nr_ranges - 1; i >= j; i--)
1236 mem->ranges[i + 1] = mem->ranges[i];
1239 mem->ranges[j].start = temp_range.start;
1240 mem->ranges[j].end = temp_range.end;
1245 int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
1246 void **addr, unsigned long *sz)
1250 unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
1252 unsigned int cpu, i;
1253 unsigned long long notes_addr;
1254 unsigned long mstart, mend;
1256 /* extra phdr for vmcoreinfo ELF note */
1257 nr_phdr = nr_cpus + 1;
1258 nr_phdr += mem->nr_ranges;
1261 * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
1262 * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
1263 * I think this is required by tools like gdb. So same physical
1264 * memory will be mapped in two ELF headers. One will contain kernel
1265 * text virtual addresses and other will have __va(physical) addresses.
1269 elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
1270 elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);
1272 buf = vzalloc(elf_sz);
1276 ehdr = (Elf64_Ehdr *)buf;
1277 phdr = (Elf64_Phdr *)(ehdr + 1);
1278 memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
1279 ehdr->e_ident[EI_CLASS] = ELFCLASS64;
1280 ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
1281 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1282 ehdr->e_ident[EI_OSABI] = ELF_OSABI;
1283 memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
1284 ehdr->e_type = ET_CORE;
1285 ehdr->e_machine = ELF_ARCH;
1286 ehdr->e_version = EV_CURRENT;
1287 ehdr->e_phoff = sizeof(Elf64_Ehdr);
1288 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1289 ehdr->e_phentsize = sizeof(Elf64_Phdr);
1291 /* Prepare one phdr of type PT_NOTE for each present CPU */
1292 for_each_present_cpu(cpu) {
1293 phdr->p_type = PT_NOTE;
1294 notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
1295 phdr->p_offset = phdr->p_paddr = notes_addr;
1296 phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
1301 /* Prepare one PT_NOTE header for vmcoreinfo */
1302 phdr->p_type = PT_NOTE;
1303 phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
1304 phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
1308 /* Prepare PT_LOAD type program header for kernel text region */
1310 phdr->p_type = PT_LOAD;
1311 phdr->p_flags = PF_R|PF_W|PF_X;
1312 phdr->p_vaddr = (unsigned long) _text;
1313 phdr->p_filesz = phdr->p_memsz = _end - _text;
1314 phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
1319 /* Go through all the ranges in mem->ranges[] and prepare phdr */
1320 for (i = 0; i < mem->nr_ranges; i++) {
1321 mstart = mem->ranges[i].start;
1322 mend = mem->ranges[i].end;
1324 phdr->p_type = PT_LOAD;
1325 phdr->p_flags = PF_R|PF_W|PF_X;
1326 phdr->p_offset = mstart;
1328 phdr->p_paddr = mstart;
1329 phdr->p_vaddr = (unsigned long) __va(mstart);
1330 phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
1333 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",
1334 phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
1335 ehdr->e_phnum, phdr->p_offset);