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/sha2.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);
43 /* Maximum size in bytes for kernel/initrd files. */
44 #define KEXEC_FILE_SIZE_MAX min_t(s64, 4LL << 30, SSIZE_MAX)
47 * Currently this is the only default function that is exported as some
48 * architectures need it to do additional handlings.
49 * In the future, other default functions may be exported too if required.
51 int kexec_image_probe_default(struct kimage *image, void *buf,
52 unsigned long buf_len)
54 const struct kexec_file_ops * const *fops;
57 for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) {
58 ret = (*fops)->probe(buf, buf_len);
68 void *kexec_image_load_default(struct kimage *image)
70 if (!image->fops || !image->fops->load)
71 return ERR_PTR(-ENOEXEC);
73 return image->fops->load(image, image->kernel_buf,
74 image->kernel_buf_len, image->initrd_buf,
75 image->initrd_buf_len, image->cmdline_buf,
76 image->cmdline_buf_len);
79 int kexec_image_post_load_cleanup_default(struct kimage *image)
81 if (!image->fops || !image->fops->cleanup)
84 return image->fops->cleanup(image->image_loader_data);
88 * Free up memory used by kernel, initrd, and command line. This is temporary
89 * memory allocation which is not needed any more after these buffers have
90 * been loaded into separate segments and have been copied elsewhere.
92 void kimage_file_post_load_cleanup(struct kimage *image)
94 struct purgatory_info *pi = &image->purgatory_info;
96 vfree(image->kernel_buf);
97 image->kernel_buf = NULL;
99 vfree(image->initrd_buf);
100 image->initrd_buf = NULL;
102 kfree(image->cmdline_buf);
103 image->cmdline_buf = NULL;
105 vfree(pi->purgatory_buf);
106 pi->purgatory_buf = NULL;
111 #ifdef CONFIG_IMA_KEXEC
112 vfree(image->ima_buffer);
113 image->ima_buffer = NULL;
114 #endif /* CONFIG_IMA_KEXEC */
116 /* See if architecture has anything to cleanup post load */
117 arch_kimage_file_post_load_cleanup(image);
120 * Above call should have called into bootloader to free up
121 * any data stored in kimage->image_loader_data. It should
122 * be ok now to free it up.
124 kfree(image->image_loader_data);
125 image->image_loader_data = NULL;
128 #ifdef CONFIG_KEXEC_SIG
129 #ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION
130 int kexec_kernel_verify_pe_sig(const char *kernel, unsigned long kernel_len)
134 ret = verify_pefile_signature(kernel, kernel_len,
135 VERIFY_USE_SECONDARY_KEYRING,
136 VERIFYING_KEXEC_PE_SIGNATURE);
137 if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) {
138 ret = verify_pefile_signature(kernel, kernel_len,
139 VERIFY_USE_PLATFORM_KEYRING,
140 VERIFYING_KEXEC_PE_SIGNATURE);
146 static int kexec_image_verify_sig(struct kimage *image, void *buf,
147 unsigned long buf_len)
149 if (!image->fops || !image->fops->verify_sig) {
150 pr_debug("kernel loader does not support signature verification.\n");
151 return -EKEYREJECTED;
154 return image->fops->verify_sig(buf, buf_len);
158 kimage_validate_signature(struct kimage *image)
162 ret = kexec_image_verify_sig(image, image->kernel_buf,
163 image->kernel_buf_len);
167 pr_notice("Enforced kernel signature verification failed (%d).\n", ret);
172 * If IMA is guaranteed to appraise a signature on the kexec
173 * image, permit it even if the kernel is otherwise locked
176 if (!ima_appraise_signature(READING_KEXEC_IMAGE) &&
177 security_locked_down(LOCKDOWN_KEXEC))
180 pr_debug("kernel signature verification failed (%d).\n", ret);
188 * In file mode list of segments is prepared by kernel. Copy relevant
189 * data from user space, do error checking, prepare segment list
192 kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
193 const char __user *cmdline_ptr,
194 unsigned long cmdline_len, unsigned flags)
199 ret = kernel_read_file_from_fd(kernel_fd, 0, &image->kernel_buf,
200 KEXEC_FILE_SIZE_MAX, NULL,
201 READING_KEXEC_IMAGE);
204 image->kernel_buf_len = ret;
206 /* Call arch image probe handlers */
207 ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
208 image->kernel_buf_len);
212 #ifdef CONFIG_KEXEC_SIG
213 ret = kimage_validate_signature(image);
218 /* It is possible that there no initramfs is being loaded */
219 if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
220 ret = kernel_read_file_from_fd(initrd_fd, 0, &image->initrd_buf,
221 KEXEC_FILE_SIZE_MAX, NULL,
222 READING_KEXEC_INITRAMFS);
225 image->initrd_buf_len = ret;
230 image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len);
231 if (IS_ERR(image->cmdline_buf)) {
232 ret = PTR_ERR(image->cmdline_buf);
233 image->cmdline_buf = NULL;
237 image->cmdline_buf_len = cmdline_len;
239 /* command line should be a string with last byte null */
240 if (image->cmdline_buf[cmdline_len - 1] != '\0') {
245 ima_kexec_cmdline(kernel_fd, image->cmdline_buf,
246 image->cmdline_buf_len - 1);
249 /* IMA needs to pass the measurement list to the next kernel. */
250 ima_add_kexec_buffer(image);
252 /* Call arch image load handlers */
253 ldata = arch_kexec_kernel_image_load(image);
256 ret = PTR_ERR(ldata);
260 image->image_loader_data = ldata;
262 /* In case of error, free up all allocated memory in this function */
264 kimage_file_post_load_cleanup(image);
269 kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
270 int initrd_fd, const char __user *cmdline_ptr,
271 unsigned long cmdline_len, unsigned long flags)
274 struct kimage *image;
275 bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
277 image = do_kimage_alloc_init();
281 image->file_mode = 1;
283 if (kexec_on_panic) {
284 /* Enable special crash kernel control page alloc policy. */
285 image->control_page = crashk_res.start;
286 image->type = KEXEC_TYPE_CRASH;
289 ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
290 cmdline_ptr, cmdline_len, flags);
294 ret = sanity_check_segment_list(image);
296 goto out_free_post_load_bufs;
299 image->control_code_page = kimage_alloc_control_pages(image,
300 get_order(KEXEC_CONTROL_PAGE_SIZE));
301 if (!image->control_code_page) {
302 pr_err("Could not allocate control_code_buffer\n");
303 goto out_free_post_load_bufs;
306 if (!kexec_on_panic) {
307 image->swap_page = kimage_alloc_control_pages(image, 0);
308 if (!image->swap_page) {
309 pr_err("Could not allocate swap buffer\n");
310 goto out_free_control_pages;
316 out_free_control_pages:
317 kimage_free_page_list(&image->control_pages);
318 out_free_post_load_bufs:
319 kimage_file_post_load_cleanup(image);
325 SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
326 unsigned long, cmdline_len, const char __user *, cmdline_ptr,
327 unsigned long, flags)
330 struct kimage **dest_image, *image;
332 /* We only trust the superuser with rebooting the system. */
333 if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
336 /* Make sure we have a legal set of flags */
337 if (flags != (flags & KEXEC_FILE_FLAGS))
342 if (!mutex_trylock(&kexec_mutex))
345 dest_image = &kexec_image;
346 if (flags & KEXEC_FILE_ON_CRASH) {
347 dest_image = &kexec_crash_image;
348 if (kexec_crash_image)
349 arch_kexec_unprotect_crashkres();
352 if (flags & KEXEC_FILE_UNLOAD)
356 * In case of crash, new kernel gets loaded in reserved region. It is
357 * same memory where old crash kernel might be loaded. Free any
358 * current crash dump kernel before we corrupt it.
360 if (flags & KEXEC_FILE_ON_CRASH)
361 kimage_free(xchg(&kexec_crash_image, NULL));
363 ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr,
368 ret = machine_kexec_prepare(image);
373 * Some architecture(like S390) may touch the crash memory before
374 * machine_kexec_prepare(), we must copy vmcoreinfo data after it.
376 ret = kimage_crash_copy_vmcoreinfo(image);
380 ret = kexec_calculate_store_digests(image);
384 for (i = 0; i < image->nr_segments; i++) {
385 struct kexec_segment *ksegment;
387 ksegment = &image->segment[i];
388 pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
389 i, ksegment->buf, ksegment->bufsz, ksegment->mem,
392 ret = kimage_load_segment(image, &image->segment[i]);
397 kimage_terminate(image);
399 ret = machine_kexec_post_load(image);
404 * Free up any temporary buffers allocated which are not needed
405 * after image has been loaded
407 kimage_file_post_load_cleanup(image);
409 image = xchg(dest_image, image);
411 if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image)
412 arch_kexec_protect_crashkres();
414 mutex_unlock(&kexec_mutex);
419 static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
420 struct kexec_buf *kbuf)
422 struct kimage *image = kbuf->image;
423 unsigned long temp_start, temp_end;
425 temp_end = min(end, kbuf->buf_max);
426 temp_start = temp_end - kbuf->memsz;
429 /* align down start */
430 temp_start = temp_start & (~(kbuf->buf_align - 1));
432 if (temp_start < start || temp_start < kbuf->buf_min)
435 temp_end = temp_start + kbuf->memsz - 1;
438 * Make sure this does not conflict with any of existing
441 if (kimage_is_destination_range(image, temp_start, temp_end)) {
442 temp_start = temp_start - PAGE_SIZE;
446 /* We found a suitable memory range */
450 /* If we are here, we found a suitable memory range */
451 kbuf->mem = temp_start;
453 /* Success, stop navigating through remaining System RAM ranges */
457 static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
458 struct kexec_buf *kbuf)
460 struct kimage *image = kbuf->image;
461 unsigned long temp_start, temp_end;
463 temp_start = max(start, kbuf->buf_min);
466 temp_start = ALIGN(temp_start, kbuf->buf_align);
467 temp_end = temp_start + kbuf->memsz - 1;
469 if (temp_end > end || temp_end > kbuf->buf_max)
472 * Make sure this does not conflict with any of existing
475 if (kimage_is_destination_range(image, temp_start, temp_end)) {
476 temp_start = temp_start + PAGE_SIZE;
480 /* We found a suitable memory range */
484 /* If we are here, we found a suitable memory range */
485 kbuf->mem = temp_start;
487 /* Success, stop navigating through remaining System RAM ranges */
491 static int locate_mem_hole_callback(struct resource *res, void *arg)
493 struct kexec_buf *kbuf = (struct kexec_buf *)arg;
494 u64 start = res->start, end = res->end;
495 unsigned long sz = end - start + 1;
497 /* Returning 0 will take to next memory range */
499 /* Don't use memory that will be detected and handled by a driver. */
500 if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED)
503 if (sz < kbuf->memsz)
506 if (end < kbuf->buf_min || start > kbuf->buf_max)
510 * Allocate memory top down with-in ram range. Otherwise bottom up
514 return locate_mem_hole_top_down(start, end, kbuf);
515 return locate_mem_hole_bottom_up(start, end, kbuf);
518 #ifdef CONFIG_ARCH_KEEP_MEMBLOCK
519 static int kexec_walk_memblock(struct kexec_buf *kbuf,
520 int (*func)(struct resource *, void *))
524 phys_addr_t mstart, mend;
525 struct resource res = { };
527 if (kbuf->image->type == KEXEC_TYPE_CRASH)
528 return func(&crashk_res, kbuf);
531 * Using MEMBLOCK_NONE will properly skip MEMBLOCK_DRIVER_MANAGED. See
532 * IORESOURCE_SYSRAM_DRIVER_MANAGED handling in
533 * locate_mem_hole_callback().
535 if (kbuf->top_down) {
536 for_each_free_mem_range_reverse(i, NUMA_NO_NODE, MEMBLOCK_NONE,
537 &mstart, &mend, NULL) {
539 * In memblock, end points to the first byte after the
540 * range while in kexec, end points to the last byte
545 ret = func(&res, kbuf);
550 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
551 &mstart, &mend, NULL) {
553 * In memblock, end points to the first byte after the
554 * range while in kexec, end points to the last byte
559 ret = func(&res, kbuf);
568 static int kexec_walk_memblock(struct kexec_buf *kbuf,
569 int (*func)(struct resource *, void *))
576 * kexec_walk_resources - call func(data) on free memory regions
577 * @kbuf: Context info for the search. Also passed to @func.
578 * @func: Function to call for each memory region.
580 * Return: The memory walk will stop when func returns a non-zero value
581 * and that value will be returned. If all free regions are visited without
582 * func returning non-zero, then zero will be returned.
584 static int kexec_walk_resources(struct kexec_buf *kbuf,
585 int (*func)(struct resource *, void *))
587 if (kbuf->image->type == KEXEC_TYPE_CRASH)
588 return walk_iomem_res_desc(crashk_res.desc,
589 IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
590 crashk_res.start, crashk_res.end,
593 return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
597 * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
598 * @kbuf: Parameters for the memory search.
600 * On success, kbuf->mem will have the start address of the memory region found.
602 * Return: 0 on success, negative errno on error.
604 int kexec_locate_mem_hole(struct kexec_buf *kbuf)
608 /* Arch knows where to place */
609 if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN)
612 if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
613 ret = kexec_walk_resources(kbuf, locate_mem_hole_callback);
615 ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback);
617 return ret == 1 ? 0 : -EADDRNOTAVAIL;
621 * kexec_add_buffer - place a buffer in a kexec segment
622 * @kbuf: Buffer contents and memory parameters.
624 * This function assumes that kexec_mutex is held.
625 * On successful return, @kbuf->mem will have the physical address of
626 * the buffer in memory.
628 * Return: 0 on success, negative errno on error.
630 int kexec_add_buffer(struct kexec_buf *kbuf)
632 struct kexec_segment *ksegment;
635 /* Currently adding segment this way is allowed only in file mode */
636 if (!kbuf->image->file_mode)
639 if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX)
643 * Make sure we are not trying to add buffer after allocating
644 * control pages. All segments need to be placed first before
645 * any control pages are allocated. As control page allocation
646 * logic goes through list of segments to make sure there are
647 * no destination overlaps.
649 if (!list_empty(&kbuf->image->control_pages)) {
654 /* Ensure minimum alignment needed for segments. */
655 kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
656 kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
658 /* Walk the RAM ranges and allocate a suitable range for the buffer */
659 ret = arch_kexec_locate_mem_hole(kbuf);
663 /* Found a suitable memory range */
664 ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
665 ksegment->kbuf = kbuf->buffer;
666 ksegment->bufsz = kbuf->bufsz;
667 ksegment->mem = kbuf->mem;
668 ksegment->memsz = kbuf->memsz;
669 kbuf->image->nr_segments++;
673 /* Calculate and store the digest of segments */
674 static int kexec_calculate_store_digests(struct kimage *image)
676 struct crypto_shash *tfm;
677 struct shash_desc *desc;
678 int ret = 0, i, j, zero_buf_sz, sha_region_sz;
679 size_t desc_size, nullsz;
682 struct kexec_sha_region *sha_regions;
683 struct purgatory_info *pi = &image->purgatory_info;
685 if (!IS_ENABLED(CONFIG_ARCH_HAS_KEXEC_PURGATORY))
688 zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
689 zero_buf_sz = PAGE_SIZE;
691 tfm = crypto_alloc_shash("sha256", 0, 0);
697 desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
698 desc = kzalloc(desc_size, GFP_KERNEL);
704 sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region);
705 sha_regions = vzalloc(sha_region_sz);
713 ret = crypto_shash_init(desc);
715 goto out_free_sha_regions;
717 digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
720 goto out_free_sha_regions;
723 for (j = i = 0; i < image->nr_segments; i++) {
724 struct kexec_segment *ksegment;
726 ksegment = &image->segment[i];
728 * Skip purgatory as it will be modified once we put digest
731 if (ksegment->kbuf == pi->purgatory_buf)
734 ret = crypto_shash_update(desc, ksegment->kbuf,
740 * Assume rest of the buffer is filled with zero and
741 * update digest accordingly.
743 nullsz = ksegment->memsz - ksegment->bufsz;
745 unsigned long bytes = nullsz;
747 if (bytes > zero_buf_sz)
749 ret = crypto_shash_update(desc, zero_buf, bytes);
758 sha_regions[j].start = ksegment->mem;
759 sha_regions[j].len = ksegment->memsz;
764 ret = crypto_shash_final(desc, digest);
766 goto out_free_digest;
767 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha_regions",
768 sha_regions, sha_region_sz, 0);
770 goto out_free_digest;
772 ret = kexec_purgatory_get_set_symbol(image, "purgatory_sha256_digest",
773 digest, SHA256_DIGEST_SIZE, 0);
775 goto out_free_digest;
780 out_free_sha_regions:
790 #ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY
792 * kexec_purgatory_setup_kbuf - prepare buffer to load purgatory.
793 * @pi: Purgatory to be loaded.
794 * @kbuf: Buffer to setup.
796 * Allocates the memory needed for the buffer. Caller is responsible to free
797 * the memory after use.
799 * Return: 0 on success, negative errno on error.
801 static int kexec_purgatory_setup_kbuf(struct purgatory_info *pi,
802 struct kexec_buf *kbuf)
804 const Elf_Shdr *sechdrs;
805 unsigned long bss_align;
806 unsigned long bss_sz;
810 sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
811 kbuf->buf_align = bss_align = 1;
812 kbuf->bufsz = bss_sz = 0;
814 for (i = 0; i < pi->ehdr->e_shnum; i++) {
815 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
818 align = sechdrs[i].sh_addralign;
819 if (sechdrs[i].sh_type != SHT_NOBITS) {
820 if (kbuf->buf_align < align)
821 kbuf->buf_align = align;
822 kbuf->bufsz = ALIGN(kbuf->bufsz, align);
823 kbuf->bufsz += sechdrs[i].sh_size;
825 if (bss_align < align)
827 bss_sz = ALIGN(bss_sz, align);
828 bss_sz += sechdrs[i].sh_size;
831 kbuf->bufsz = ALIGN(kbuf->bufsz, bss_align);
832 kbuf->memsz = kbuf->bufsz + bss_sz;
833 if (kbuf->buf_align < bss_align)
834 kbuf->buf_align = bss_align;
836 kbuf->buffer = vzalloc(kbuf->bufsz);
839 pi->purgatory_buf = kbuf->buffer;
841 ret = kexec_add_buffer(kbuf);
847 vfree(pi->purgatory_buf);
848 pi->purgatory_buf = NULL;
853 * kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer.
854 * @pi: Purgatory to be loaded.
855 * @kbuf: Buffer prepared to store purgatory.
857 * Allocates the memory needed for the buffer. Caller is responsible to free
858 * the memory after use.
860 * Return: 0 on success, negative errno on error.
862 static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
863 struct kexec_buf *kbuf)
865 unsigned long bss_addr;
866 unsigned long offset;
871 * The section headers in kexec_purgatory are read-only. In order to
872 * have them modifiable make a temporary copy.
874 sechdrs = vzalloc(array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum));
877 memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff,
878 pi->ehdr->e_shnum * sizeof(Elf_Shdr));
879 pi->sechdrs = sechdrs;
882 bss_addr = kbuf->mem + kbuf->bufsz;
883 kbuf->image->start = pi->ehdr->e_entry;
885 for (i = 0; i < pi->ehdr->e_shnum; i++) {
889 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
892 align = sechdrs[i].sh_addralign;
893 if (sechdrs[i].sh_type == SHT_NOBITS) {
894 bss_addr = ALIGN(bss_addr, align);
895 sechdrs[i].sh_addr = bss_addr;
896 bss_addr += sechdrs[i].sh_size;
900 offset = ALIGN(offset, align);
901 if (sechdrs[i].sh_flags & SHF_EXECINSTR &&
902 pi->ehdr->e_entry >= sechdrs[i].sh_addr &&
903 pi->ehdr->e_entry < (sechdrs[i].sh_addr
904 + sechdrs[i].sh_size)) {
905 kbuf->image->start -= sechdrs[i].sh_addr;
906 kbuf->image->start += kbuf->mem + offset;
909 src = (void *)pi->ehdr + sechdrs[i].sh_offset;
910 dst = pi->purgatory_buf + offset;
911 memcpy(dst, src, sechdrs[i].sh_size);
913 sechdrs[i].sh_addr = kbuf->mem + offset;
914 sechdrs[i].sh_offset = offset;
915 offset += sechdrs[i].sh_size;
921 static int kexec_apply_relocations(struct kimage *image)
924 struct purgatory_info *pi = &image->purgatory_info;
925 const Elf_Shdr *sechdrs;
927 sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
929 for (i = 0; i < pi->ehdr->e_shnum; i++) {
930 const Elf_Shdr *relsec;
931 const Elf_Shdr *symtab;
934 relsec = sechdrs + i;
936 if (relsec->sh_type != SHT_RELA &&
937 relsec->sh_type != SHT_REL)
941 * For section of type SHT_RELA/SHT_REL,
942 * ->sh_link contains section header index of associated
943 * symbol table. And ->sh_info contains section header
944 * index of section to which relocations apply.
946 if (relsec->sh_info >= pi->ehdr->e_shnum ||
947 relsec->sh_link >= pi->ehdr->e_shnum)
950 section = pi->sechdrs + relsec->sh_info;
951 symtab = sechdrs + relsec->sh_link;
953 if (!(section->sh_flags & SHF_ALLOC))
957 * symtab->sh_link contain section header index of associated
960 if (symtab->sh_link >= pi->ehdr->e_shnum)
961 /* Invalid section number? */
965 * Respective architecture needs to provide support for applying
966 * relocations of type SHT_RELA/SHT_REL.
968 if (relsec->sh_type == SHT_RELA)
969 ret = arch_kexec_apply_relocations_add(pi, section,
971 else if (relsec->sh_type == SHT_REL)
972 ret = arch_kexec_apply_relocations(pi, section,
982 * kexec_load_purgatory - Load and relocate the purgatory object.
983 * @image: Image to add the purgatory to.
984 * @kbuf: Memory parameters to use.
986 * Allocates the memory needed for image->purgatory_info.sechdrs and
987 * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible
988 * to free the memory after use.
990 * Return: 0 on success, negative errno on error.
992 int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf)
994 struct purgatory_info *pi = &image->purgatory_info;
997 if (kexec_purgatory_size <= 0)
1000 pi->ehdr = (const Elf_Ehdr *)kexec_purgatory;
1002 ret = kexec_purgatory_setup_kbuf(pi, kbuf);
1006 ret = kexec_purgatory_setup_sechdrs(pi, kbuf);
1010 ret = kexec_apply_relocations(image);
1019 vfree(pi->purgatory_buf);
1020 pi->purgatory_buf = NULL;
1025 * kexec_purgatory_find_symbol - find a symbol in the purgatory
1026 * @pi: Purgatory to search in.
1027 * @name: Name of the symbol.
1029 * Return: pointer to symbol in read-only symtab on success, NULL on error.
1031 static const Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
1034 const Elf_Shdr *sechdrs;
1035 const Elf_Ehdr *ehdr;
1036 const Elf_Sym *syms;
1044 sechdrs = (void *)ehdr + ehdr->e_shoff;
1046 for (i = 0; i < ehdr->e_shnum; i++) {
1047 if (sechdrs[i].sh_type != SHT_SYMTAB)
1050 if (sechdrs[i].sh_link >= ehdr->e_shnum)
1051 /* Invalid strtab section number */
1053 strtab = (void *)ehdr + sechdrs[sechdrs[i].sh_link].sh_offset;
1054 syms = (void *)ehdr + sechdrs[i].sh_offset;
1056 /* Go through symbols for a match */
1057 for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
1058 if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
1061 if (strcmp(strtab + syms[k].st_name, name) != 0)
1064 if (syms[k].st_shndx == SHN_UNDEF ||
1065 syms[k].st_shndx >= ehdr->e_shnum) {
1066 pr_debug("Symbol: %s has bad section index %d.\n",
1067 name, syms[k].st_shndx);
1071 /* Found the symbol we are looking for */
1079 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
1081 struct purgatory_info *pi = &image->purgatory_info;
1085 sym = kexec_purgatory_find_symbol(pi, name);
1087 return ERR_PTR(-EINVAL);
1089 sechdr = &pi->sechdrs[sym->st_shndx];
1092 * Returns the address where symbol will finally be loaded after
1093 * kexec_load_segment()
1095 return (void *)(sechdr->sh_addr + sym->st_value);
1099 * Get or set value of a symbol. If "get_value" is true, symbol value is
1100 * returned in buf otherwise symbol value is set based on value in buf.
1102 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
1103 void *buf, unsigned int size, bool get_value)
1105 struct purgatory_info *pi = &image->purgatory_info;
1110 sym = kexec_purgatory_find_symbol(pi, name);
1114 if (sym->st_size != size) {
1115 pr_err("symbol %s size mismatch: expected %lu actual %u\n",
1116 name, (unsigned long)sym->st_size, size);
1120 sec = pi->sechdrs + sym->st_shndx;
1122 if (sec->sh_type == SHT_NOBITS) {
1123 pr_err("symbol %s is in a bss section. Cannot %s\n", name,
1124 get_value ? "get" : "set");
1128 sym_buf = (char *)pi->purgatory_buf + sec->sh_offset + sym->st_value;
1131 memcpy((void *)buf, sym_buf, size);
1133 memcpy((void *)sym_buf, buf, size);
1137 #endif /* CONFIG_ARCH_HAS_KEXEC_PURGATORY */
1139 int crash_exclude_mem_range(struct crash_mem *mem,
1140 unsigned long long mstart, unsigned long long mend)
1143 unsigned long long start, end, p_start, p_end;
1144 struct crash_mem_range temp_range = {0, 0};
1146 for (i = 0; i < mem->nr_ranges; i++) {
1147 start = mem->ranges[i].start;
1148 end = mem->ranges[i].end;
1152 if (mstart > end || mend < start)
1155 /* Truncate any area outside of range */
1161 /* Found completely overlapping range */
1162 if (p_start == start && p_end == end) {
1163 mem->ranges[i].start = 0;
1164 mem->ranges[i].end = 0;
1165 if (i < mem->nr_ranges - 1) {
1166 /* Shift rest of the ranges to left */
1167 for (j = i; j < mem->nr_ranges - 1; j++) {
1168 mem->ranges[j].start =
1169 mem->ranges[j+1].start;
1170 mem->ranges[j].end =
1171 mem->ranges[j+1].end;
1175 * Continue to check if there are another overlapping ranges
1176 * from the current position because of shifting the above
1187 if (p_start > start && p_end < end) {
1188 /* Split original range */
1189 mem->ranges[i].end = p_start - 1;
1190 temp_range.start = p_end + 1;
1191 temp_range.end = end;
1192 } else if (p_start != start)
1193 mem->ranges[i].end = p_start - 1;
1195 mem->ranges[i].start = p_end + 1;
1199 /* If a split happened, add the split to array */
1200 if (!temp_range.end)
1203 /* Split happened */
1204 if (i == mem->max_nr_ranges - 1)
1207 /* Location where new range should go */
1209 if (j < mem->nr_ranges) {
1210 /* Move over all ranges one slot towards the end */
1211 for (i = mem->nr_ranges - 1; i >= j; i--)
1212 mem->ranges[i + 1] = mem->ranges[i];
1215 mem->ranges[j].start = temp_range.start;
1216 mem->ranges[j].end = temp_range.end;
1221 int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
1222 void **addr, unsigned long *sz)
1226 unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
1228 unsigned int cpu, i;
1229 unsigned long long notes_addr;
1230 unsigned long mstart, mend;
1232 /* extra phdr for vmcoreinfo ELF note */
1233 nr_phdr = nr_cpus + 1;
1234 nr_phdr += mem->nr_ranges;
1237 * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
1238 * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
1239 * I think this is required by tools like gdb. So same physical
1240 * memory will be mapped in two ELF headers. One will contain kernel
1241 * text virtual addresses and other will have __va(physical) addresses.
1245 elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
1246 elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);
1248 buf = vzalloc(elf_sz);
1252 ehdr = (Elf64_Ehdr *)buf;
1253 phdr = (Elf64_Phdr *)(ehdr + 1);
1254 memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
1255 ehdr->e_ident[EI_CLASS] = ELFCLASS64;
1256 ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
1257 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1258 ehdr->e_ident[EI_OSABI] = ELF_OSABI;
1259 memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
1260 ehdr->e_type = ET_CORE;
1261 ehdr->e_machine = ELF_ARCH;
1262 ehdr->e_version = EV_CURRENT;
1263 ehdr->e_phoff = sizeof(Elf64_Ehdr);
1264 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1265 ehdr->e_phentsize = sizeof(Elf64_Phdr);
1267 /* Prepare one phdr of type PT_NOTE for each present CPU */
1268 for_each_present_cpu(cpu) {
1269 phdr->p_type = PT_NOTE;
1270 notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
1271 phdr->p_offset = phdr->p_paddr = notes_addr;
1272 phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
1277 /* Prepare one PT_NOTE header for vmcoreinfo */
1278 phdr->p_type = PT_NOTE;
1279 phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
1280 phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
1284 /* Prepare PT_LOAD type program header for kernel text region */
1285 if (need_kernel_map) {
1286 phdr->p_type = PT_LOAD;
1287 phdr->p_flags = PF_R|PF_W|PF_X;
1288 phdr->p_vaddr = (unsigned long) _text;
1289 phdr->p_filesz = phdr->p_memsz = _end - _text;
1290 phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
1295 /* Go through all the ranges in mem->ranges[] and prepare phdr */
1296 for (i = 0; i < mem->nr_ranges; i++) {
1297 mstart = mem->ranges[i].start;
1298 mend = mem->ranges[i].end;
1300 phdr->p_type = PT_LOAD;
1301 phdr->p_flags = PF_R|PF_W|PF_X;
1302 phdr->p_offset = mstart;
1304 phdr->p_paddr = mstart;
1305 phdr->p_vaddr = (unsigned long) __va(mstart);
1306 phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
1309 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",
1310 phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
1311 ehdr->e_phnum, phdr->p_offset);