2 * kexec: kexec_file_load system call
4 * Copyright (C) 2014 Red Hat Inc.
6 * Vivek Goyal <vgoyal@redhat.com>
8 * This source code is licensed under the GNU General Public License,
9 * Version 2. See the file COPYING for more details.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/capability.h>
16 #include <linux/file.h>
17 #include <linux/slab.h>
18 #include <linux/kexec.h>
19 #include <linux/mutex.h>
20 #include <linux/list.h>
22 #include <crypto/hash.h>
23 #include <crypto/sha.h>
24 #include <linux/syscalls.h>
25 #include <linux/vmalloc.h>
26 #include "kexec_internal.h"
29 * Declare these symbols weak so that if architecture provides a purgatory,
30 * these will be overridden.
32 char __weak kexec_purgatory[0];
33 size_t __weak kexec_purgatory_size = 0;
35 static int kexec_calculate_store_digests(struct kimage *image);
37 /* Architectures can provide this probe function */
38 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
39 unsigned long buf_len)
44 void * __weak arch_kexec_kernel_image_load(struct kimage *image)
46 return ERR_PTR(-ENOEXEC);
49 int __weak arch_kimage_file_post_load_cleanup(struct kimage *image)
54 #ifdef CONFIG_KEXEC_VERIFY_SIG
55 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
56 unsigned long buf_len)
62 /* Apply relocations of type RELA */
64 arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
67 pr_err("RELA relocation unsupported.\n");
71 /* Apply relocations of type REL */
73 arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
76 pr_err("REL relocation unsupported.\n");
81 * Free up memory used by kernel, initrd, and command line. This is temporary
82 * memory allocation which is not needed any more after these buffers have
83 * been loaded into separate segments and have been copied elsewhere.
85 void kimage_file_post_load_cleanup(struct kimage *image)
87 struct purgatory_info *pi = &image->purgatory_info;
89 vfree(image->kernel_buf);
90 image->kernel_buf = NULL;
92 vfree(image->initrd_buf);
93 image->initrd_buf = NULL;
95 kfree(image->cmdline_buf);
96 image->cmdline_buf = NULL;
98 vfree(pi->purgatory_buf);
99 pi->purgatory_buf = NULL;
104 /* See if architecture has anything to cleanup post load */
105 arch_kimage_file_post_load_cleanup(image);
108 * Above call should have called into bootloader to free up
109 * any data stored in kimage->image_loader_data. It should
110 * be ok now to free it up.
112 kfree(image->image_loader_data);
113 image->image_loader_data = NULL;
117 * In file mode list of segments is prepared by kernel. Copy relevant
118 * data from user space, do error checking, prepare segment list
121 kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
122 const char __user *cmdline_ptr,
123 unsigned long cmdline_len, unsigned flags)
129 ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf,
130 &size, INT_MAX, READING_KEXEC_IMAGE);
133 image->kernel_buf_len = size;
135 /* Call arch image probe handlers */
136 ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
137 image->kernel_buf_len);
141 #ifdef CONFIG_KEXEC_VERIFY_SIG
142 ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf,
143 image->kernel_buf_len);
145 pr_debug("kernel signature verification failed.\n");
148 pr_debug("kernel signature verification successful.\n");
150 /* It is possible that there no initramfs is being loaded */
151 if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
152 ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf,
154 READING_KEXEC_INITRAMFS);
157 image->initrd_buf_len = size;
161 image->cmdline_buf = kzalloc(cmdline_len, GFP_KERNEL);
162 if (!image->cmdline_buf) {
167 ret = copy_from_user(image->cmdline_buf, cmdline_ptr,
174 image->cmdline_buf_len = cmdline_len;
176 /* command line should be a string with last byte null */
177 if (image->cmdline_buf[cmdline_len - 1] != '\0') {
183 /* Call arch image load handlers */
184 ldata = arch_kexec_kernel_image_load(image);
187 ret = PTR_ERR(ldata);
191 image->image_loader_data = ldata;
193 /* In case of error, free up all allocated memory in this function */
195 kimage_file_post_load_cleanup(image);
200 kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
201 int initrd_fd, const char __user *cmdline_ptr,
202 unsigned long cmdline_len, unsigned long flags)
205 struct kimage *image;
206 bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
208 image = do_kimage_alloc_init();
212 image->file_mode = 1;
214 if (kexec_on_panic) {
215 /* Enable special crash kernel control page alloc policy. */
216 image->control_page = crashk_res.start;
217 image->type = KEXEC_TYPE_CRASH;
220 ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
221 cmdline_ptr, cmdline_len, flags);
225 ret = sanity_check_segment_list(image);
227 goto out_free_post_load_bufs;
230 image->control_code_page = kimage_alloc_control_pages(image,
231 get_order(KEXEC_CONTROL_PAGE_SIZE));
232 if (!image->control_code_page) {
233 pr_err("Could not allocate control_code_buffer\n");
234 goto out_free_post_load_bufs;
237 if (!kexec_on_panic) {
238 image->swap_page = kimage_alloc_control_pages(image, 0);
239 if (!image->swap_page) {
240 pr_err("Could not allocate swap buffer\n");
241 goto out_free_control_pages;
247 out_free_control_pages:
248 kimage_free_page_list(&image->control_pages);
249 out_free_post_load_bufs:
250 kimage_file_post_load_cleanup(image);
256 SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
257 unsigned long, cmdline_len, const char __user *, cmdline_ptr,
258 unsigned long, flags)
261 struct kimage **dest_image, *image;
263 /* We only trust the superuser with rebooting the system. */
264 if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
267 /* Make sure we have a legal set of flags */
268 if (flags != (flags & KEXEC_FILE_FLAGS))
273 if (!mutex_trylock(&kexec_mutex))
276 dest_image = &kexec_image;
277 if (flags & KEXEC_FILE_ON_CRASH) {
278 dest_image = &kexec_crash_image;
279 if (kexec_crash_image)
280 arch_kexec_unprotect_crashkres();
283 if (flags & KEXEC_FILE_UNLOAD)
287 * In case of crash, new kernel gets loaded in reserved region. It is
288 * same memory where old crash kernel might be loaded. Free any
289 * current crash dump kernel before we corrupt it.
291 if (flags & KEXEC_FILE_ON_CRASH)
292 kimage_free(xchg(&kexec_crash_image, NULL));
294 ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr,
299 ret = machine_kexec_prepare(image);
303 ret = kexec_calculate_store_digests(image);
307 for (i = 0; i < image->nr_segments; i++) {
308 struct kexec_segment *ksegment;
310 ksegment = &image->segment[i];
311 pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
312 i, ksegment->buf, ksegment->bufsz, ksegment->mem,
315 ret = kimage_load_segment(image, &image->segment[i]);
320 kimage_terminate(image);
323 * Free up any temporary buffers allocated which are not needed
324 * after image has been loaded
326 kimage_file_post_load_cleanup(image);
328 image = xchg(dest_image, image);
330 if ((flags & KEXEC_FILE_ON_CRASH) && kexec_crash_image)
331 arch_kexec_protect_crashkres();
333 mutex_unlock(&kexec_mutex);
338 static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
339 struct kexec_buf *kbuf)
341 struct kimage *image = kbuf->image;
342 unsigned long temp_start, temp_end;
344 temp_end = min(end, kbuf->buf_max);
345 temp_start = temp_end - kbuf->memsz;
348 /* align down start */
349 temp_start = temp_start & (~(kbuf->buf_align - 1));
351 if (temp_start < start || temp_start < kbuf->buf_min)
354 temp_end = temp_start + kbuf->memsz - 1;
357 * Make sure this does not conflict with any of existing
360 if (kimage_is_destination_range(image, temp_start, temp_end)) {
361 temp_start = temp_start - PAGE_SIZE;
365 /* We found a suitable memory range */
369 /* If we are here, we found a suitable memory range */
370 kbuf->mem = temp_start;
372 /* Success, stop navigating through remaining System RAM ranges */
376 static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
377 struct kexec_buf *kbuf)
379 struct kimage *image = kbuf->image;
380 unsigned long temp_start, temp_end;
382 temp_start = max(start, kbuf->buf_min);
385 temp_start = ALIGN(temp_start, kbuf->buf_align);
386 temp_end = temp_start + kbuf->memsz - 1;
388 if (temp_end > end || temp_end > kbuf->buf_max)
391 * Make sure this does not conflict with any of existing
394 if (kimage_is_destination_range(image, temp_start, temp_end)) {
395 temp_start = temp_start + PAGE_SIZE;
399 /* We found a suitable memory range */
403 /* If we are here, we found a suitable memory range */
404 kbuf->mem = temp_start;
406 /* Success, stop navigating through remaining System RAM ranges */
410 static int locate_mem_hole_callback(u64 start, u64 end, void *arg)
412 struct kexec_buf *kbuf = (struct kexec_buf *)arg;
413 unsigned long sz = end - start + 1;
415 /* Returning 0 will take to next memory range */
416 if (sz < kbuf->memsz)
419 if (end < kbuf->buf_min || start > kbuf->buf_max)
423 * Allocate memory top down with-in ram range. Otherwise bottom up
427 return locate_mem_hole_top_down(start, end, kbuf);
428 return locate_mem_hole_bottom_up(start, end, kbuf);
432 * Helper function for placing a buffer in a kexec segment. This assumes
433 * that kexec_mutex is held.
435 int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
436 unsigned long memsz, unsigned long buf_align,
437 unsigned long buf_min, unsigned long buf_max,
438 bool top_down, unsigned long *load_addr)
441 struct kexec_segment *ksegment;
442 struct kexec_buf buf, *kbuf;
445 /* Currently adding segment this way is allowed only in file mode */
446 if (!image->file_mode)
449 if (image->nr_segments >= KEXEC_SEGMENT_MAX)
453 * Make sure we are not trying to add buffer after allocating
454 * control pages. All segments need to be placed first before
455 * any control pages are allocated. As control page allocation
456 * logic goes through list of segments to make sure there are
457 * no destination overlaps.
459 if (!list_empty(&image->control_pages)) {
464 memset(&buf, 0, sizeof(struct kexec_buf));
467 kbuf->buffer = buffer;
470 kbuf->memsz = ALIGN(memsz, PAGE_SIZE);
471 kbuf->buf_align = max(buf_align, PAGE_SIZE);
472 kbuf->buf_min = buf_min;
473 kbuf->buf_max = buf_max;
474 kbuf->top_down = top_down;
476 /* Walk the RAM ranges and allocate a suitable range for the buffer */
477 if (image->type == KEXEC_TYPE_CRASH)
478 ret = walk_iomem_res_desc(crashk_res.desc,
479 IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
480 crashk_res.start, crashk_res.end, kbuf,
481 locate_mem_hole_callback);
483 ret = walk_system_ram_res(0, -1, kbuf,
484 locate_mem_hole_callback);
486 /* A suitable memory range could not be found for buffer */
487 return -EADDRNOTAVAIL;
490 /* Found a suitable memory range */
491 ksegment = &image->segment[image->nr_segments];
492 ksegment->kbuf = kbuf->buffer;
493 ksegment->bufsz = kbuf->bufsz;
494 ksegment->mem = kbuf->mem;
495 ksegment->memsz = kbuf->memsz;
496 image->nr_segments++;
497 *load_addr = ksegment->mem;
501 /* Calculate and store the digest of segments */
502 static int kexec_calculate_store_digests(struct kimage *image)
504 struct crypto_shash *tfm;
505 struct shash_desc *desc;
506 int ret = 0, i, j, zero_buf_sz, sha_region_sz;
507 size_t desc_size, nullsz;
510 struct kexec_sha_region *sha_regions;
511 struct purgatory_info *pi = &image->purgatory_info;
513 zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
514 zero_buf_sz = PAGE_SIZE;
516 tfm = crypto_alloc_shash("sha256", 0, 0);
522 desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
523 desc = kzalloc(desc_size, GFP_KERNEL);
529 sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region);
530 sha_regions = vzalloc(sha_region_sz);
537 ret = crypto_shash_init(desc);
539 goto out_free_sha_regions;
541 digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
544 goto out_free_sha_regions;
547 for (j = i = 0; i < image->nr_segments; i++) {
548 struct kexec_segment *ksegment;
550 ksegment = &image->segment[i];
552 * Skip purgatory as it will be modified once we put digest
555 if (ksegment->kbuf == pi->purgatory_buf)
558 ret = crypto_shash_update(desc, ksegment->kbuf,
564 * Assume rest of the buffer is filled with zero and
565 * update digest accordingly.
567 nullsz = ksegment->memsz - ksegment->bufsz;
569 unsigned long bytes = nullsz;
571 if (bytes > zero_buf_sz)
573 ret = crypto_shash_update(desc, zero_buf, bytes);
582 sha_regions[j].start = ksegment->mem;
583 sha_regions[j].len = ksegment->memsz;
588 ret = crypto_shash_final(desc, digest);
590 goto out_free_digest;
591 ret = kexec_purgatory_get_set_symbol(image, "sha_regions",
592 sha_regions, sha_region_sz, 0);
594 goto out_free_digest;
596 ret = kexec_purgatory_get_set_symbol(image, "sha256_digest",
597 digest, SHA256_DIGEST_SIZE, 0);
599 goto out_free_digest;
604 out_free_sha_regions:
614 /* Actually load purgatory. Lot of code taken from kexec-tools */
615 static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
616 unsigned long max, int top_down)
618 struct purgatory_info *pi = &image->purgatory_info;
619 unsigned long align, buf_align, bss_align, buf_sz, bss_sz, bss_pad;
620 unsigned long memsz, entry, load_addr, curr_load_addr, bss_addr, offset;
621 unsigned char *buf_addr, *src;
622 int i, ret = 0, entry_sidx = -1;
623 const Elf_Shdr *sechdrs_c;
624 Elf_Shdr *sechdrs = NULL;
625 void *purgatory_buf = NULL;
628 * sechdrs_c points to section headers in purgatory and are read
629 * only. No modifications allowed.
631 sechdrs_c = (void *)pi->ehdr + pi->ehdr->e_shoff;
634 * We can not modify sechdrs_c[] and its fields. It is read only.
635 * Copy it over to a local copy where one can store some temporary
636 * data and free it at the end. We need to modify ->sh_addr and
637 * ->sh_offset fields to keep track of permanent and temporary
638 * locations of sections.
640 sechdrs = vzalloc(pi->ehdr->e_shnum * sizeof(Elf_Shdr));
644 memcpy(sechdrs, sechdrs_c, pi->ehdr->e_shnum * sizeof(Elf_Shdr));
647 * We seem to have multiple copies of sections. First copy is which
648 * is embedded in kernel in read only section. Some of these sections
649 * will be copied to a temporary buffer and relocated. And these
650 * sections will finally be copied to their final destination at
653 * Use ->sh_offset to reflect section address in memory. It will
654 * point to original read only copy if section is not allocatable.
655 * Otherwise it will point to temporary copy which will be relocated.
657 * Use ->sh_addr to contain final address of the section where it
658 * will go during execution time.
660 for (i = 0; i < pi->ehdr->e_shnum; i++) {
661 if (sechdrs[i].sh_type == SHT_NOBITS)
664 sechdrs[i].sh_offset = (unsigned long)pi->ehdr +
665 sechdrs[i].sh_offset;
669 * Identify entry point section and make entry relative to section
672 entry = pi->ehdr->e_entry;
673 for (i = 0; i < pi->ehdr->e_shnum; i++) {
674 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
677 if (!(sechdrs[i].sh_flags & SHF_EXECINSTR))
680 /* Make entry section relative */
681 if (sechdrs[i].sh_addr <= pi->ehdr->e_entry &&
682 ((sechdrs[i].sh_addr + sechdrs[i].sh_size) >
683 pi->ehdr->e_entry)) {
685 entry -= sechdrs[i].sh_addr;
690 /* Determine how much memory is needed to load relocatable object. */
696 for (i = 0; i < pi->ehdr->e_shnum; i++) {
697 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
700 align = sechdrs[i].sh_addralign;
701 if (sechdrs[i].sh_type != SHT_NOBITS) {
702 if (buf_align < align)
704 buf_sz = ALIGN(buf_sz, align);
705 buf_sz += sechdrs[i].sh_size;
708 if (bss_align < align)
710 bss_sz = ALIGN(bss_sz, align);
711 bss_sz += sechdrs[i].sh_size;
715 /* Determine the bss padding required to align bss properly */
717 if (buf_sz & (bss_align - 1))
718 bss_pad = bss_align - (buf_sz & (bss_align - 1));
720 memsz = buf_sz + bss_pad + bss_sz;
722 /* Allocate buffer for purgatory */
723 purgatory_buf = vzalloc(buf_sz);
724 if (!purgatory_buf) {
729 if (buf_align < bss_align)
730 buf_align = bss_align;
732 /* Add buffer to segment list */
733 ret = kexec_add_buffer(image, purgatory_buf, buf_sz, memsz,
734 buf_align, min, max, top_down,
735 &pi->purgatory_load_addr);
739 /* Load SHF_ALLOC sections */
740 buf_addr = purgatory_buf;
741 load_addr = curr_load_addr = pi->purgatory_load_addr;
742 bss_addr = load_addr + buf_sz + bss_pad;
744 for (i = 0; i < pi->ehdr->e_shnum; i++) {
745 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
748 align = sechdrs[i].sh_addralign;
749 if (sechdrs[i].sh_type != SHT_NOBITS) {
750 curr_load_addr = ALIGN(curr_load_addr, align);
751 offset = curr_load_addr - load_addr;
752 /* We already modifed ->sh_offset to keep src addr */
753 src = (char *) sechdrs[i].sh_offset;
754 memcpy(buf_addr + offset, src, sechdrs[i].sh_size);
756 /* Store load address and source address of section */
757 sechdrs[i].sh_addr = curr_load_addr;
760 * This section got copied to temporary buffer. Update
761 * ->sh_offset accordingly.
763 sechdrs[i].sh_offset = (unsigned long)(buf_addr + offset);
765 /* Advance to the next address */
766 curr_load_addr += sechdrs[i].sh_size;
768 bss_addr = ALIGN(bss_addr, align);
769 sechdrs[i].sh_addr = bss_addr;
770 bss_addr += sechdrs[i].sh_size;
774 /* Update entry point based on load address of text section */
776 entry += sechdrs[entry_sidx].sh_addr;
778 /* Make kernel jump to purgatory after shutdown */
779 image->start = entry;
781 /* Used later to get/set symbol values */
782 pi->sechdrs = sechdrs;
785 * Used later to identify which section is purgatory and skip it
788 pi->purgatory_buf = purgatory_buf;
792 vfree(purgatory_buf);
796 static int kexec_apply_relocations(struct kimage *image)
799 struct purgatory_info *pi = &image->purgatory_info;
800 Elf_Shdr *sechdrs = pi->sechdrs;
802 /* Apply relocations */
803 for (i = 0; i < pi->ehdr->e_shnum; i++) {
804 Elf_Shdr *section, *symtab;
806 if (sechdrs[i].sh_type != SHT_RELA &&
807 sechdrs[i].sh_type != SHT_REL)
811 * For section of type SHT_RELA/SHT_REL,
812 * ->sh_link contains section header index of associated
813 * symbol table. And ->sh_info contains section header
814 * index of section to which relocations apply.
816 if (sechdrs[i].sh_info >= pi->ehdr->e_shnum ||
817 sechdrs[i].sh_link >= pi->ehdr->e_shnum)
820 section = &sechdrs[sechdrs[i].sh_info];
821 symtab = &sechdrs[sechdrs[i].sh_link];
823 if (!(section->sh_flags & SHF_ALLOC))
827 * symtab->sh_link contain section header index of associated
830 if (symtab->sh_link >= pi->ehdr->e_shnum)
831 /* Invalid section number? */
835 * Respective architecture needs to provide support for applying
836 * relocations of type SHT_RELA/SHT_REL.
838 if (sechdrs[i].sh_type == SHT_RELA)
839 ret = arch_kexec_apply_relocations_add(pi->ehdr,
841 else if (sechdrs[i].sh_type == SHT_REL)
842 ret = arch_kexec_apply_relocations(pi->ehdr,
851 /* Load relocatable purgatory object and relocate it appropriately */
852 int kexec_load_purgatory(struct kimage *image, unsigned long min,
853 unsigned long max, int top_down,
854 unsigned long *load_addr)
856 struct purgatory_info *pi = &image->purgatory_info;
859 if (kexec_purgatory_size <= 0)
862 if (kexec_purgatory_size < sizeof(Elf_Ehdr))
865 pi->ehdr = (Elf_Ehdr *)kexec_purgatory;
867 if (memcmp(pi->ehdr->e_ident, ELFMAG, SELFMAG) != 0
868 || pi->ehdr->e_type != ET_REL
869 || !elf_check_arch(pi->ehdr)
870 || pi->ehdr->e_shentsize != sizeof(Elf_Shdr))
873 if (pi->ehdr->e_shoff >= kexec_purgatory_size
874 || (pi->ehdr->e_shnum * sizeof(Elf_Shdr) >
875 kexec_purgatory_size - pi->ehdr->e_shoff))
878 ret = __kexec_load_purgatory(image, min, max, top_down);
882 ret = kexec_apply_relocations(image);
886 *load_addr = pi->purgatory_load_addr;
892 vfree(pi->purgatory_buf);
893 pi->purgatory_buf = NULL;
897 static Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
906 if (!pi->sechdrs || !pi->ehdr)
909 sechdrs = pi->sechdrs;
912 for (i = 0; i < ehdr->e_shnum; i++) {
913 if (sechdrs[i].sh_type != SHT_SYMTAB)
916 if (sechdrs[i].sh_link >= ehdr->e_shnum)
917 /* Invalid strtab section number */
919 strtab = (char *)sechdrs[sechdrs[i].sh_link].sh_offset;
920 syms = (Elf_Sym *)sechdrs[i].sh_offset;
922 /* Go through symbols for a match */
923 for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
924 if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
927 if (strcmp(strtab + syms[k].st_name, name) != 0)
930 if (syms[k].st_shndx == SHN_UNDEF ||
931 syms[k].st_shndx >= ehdr->e_shnum) {
932 pr_debug("Symbol: %s has bad section index %d.\n",
933 name, syms[k].st_shndx);
937 /* Found the symbol we are looking for */
945 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
947 struct purgatory_info *pi = &image->purgatory_info;
951 sym = kexec_purgatory_find_symbol(pi, name);
953 return ERR_PTR(-EINVAL);
955 sechdr = &pi->sechdrs[sym->st_shndx];
958 * Returns the address where symbol will finally be loaded after
959 * kexec_load_segment()
961 return (void *)(sechdr->sh_addr + sym->st_value);
965 * Get or set value of a symbol. If "get_value" is true, symbol value is
966 * returned in buf otherwise symbol value is set based on value in buf.
968 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
969 void *buf, unsigned int size, bool get_value)
973 struct purgatory_info *pi = &image->purgatory_info;
976 sym = kexec_purgatory_find_symbol(pi, name);
980 if (sym->st_size != size) {
981 pr_err("symbol %s size mismatch: expected %lu actual %u\n",
982 name, (unsigned long)sym->st_size, size);
986 sechdrs = pi->sechdrs;
988 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
989 pr_err("symbol %s is in a bss section. Cannot %s\n", name,
990 get_value ? "get" : "set");
994 sym_buf = (unsigned char *)sechdrs[sym->st_shndx].sh_offset +
998 memcpy((void *)buf, sym_buf, size);
1000 memcpy((void *)sym_buf, buf, size);