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>
21 #include <crypto/hash.h>
22 #include <crypto/sha.h>
23 #include <linux/syscalls.h>
24 #include <linux/vmalloc.h>
25 #include "kexec_internal.h"
28 * Declare these symbols weak so that if architecture provides a purgatory,
29 * these will be overridden.
31 char __weak kexec_purgatory[0];
32 size_t __weak kexec_purgatory_size = 0;
34 static int kexec_calculate_store_digests(struct kimage *image);
36 static int copy_file_from_fd(int fd, void **buf, unsigned long *buf_len)
38 struct fd f = fdget(fd);
47 ret = vfs_getattr(&f.file->f_path, &stat);
51 if (stat.size > INT_MAX) {
56 /* Don't hand 0 to vmalloc, it whines. */
62 *buf = vmalloc(stat.size);
69 while (pos < stat.size) {
70 bytes = kernel_read(f.file, pos, (char *)(*buf) + pos,
83 if (pos != stat.size) {
95 /* Architectures can provide this probe function */
96 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
97 unsigned long buf_len)
102 void * __weak arch_kexec_kernel_image_load(struct kimage *image)
104 return ERR_PTR(-ENOEXEC);
107 int __weak arch_kimage_file_post_load_cleanup(struct kimage *image)
112 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
113 unsigned long buf_len)
115 return -EKEYREJECTED;
118 /* Apply relocations of type RELA */
120 arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
123 pr_err("RELA relocation unsupported.\n");
127 /* Apply relocations of type REL */
129 arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
132 pr_err("REL relocation unsupported.\n");
137 * Free up memory used by kernel, initrd, and command line. This is temporary
138 * memory allocation which is not needed any more after these buffers have
139 * been loaded into separate segments and have been copied elsewhere.
141 void kimage_file_post_load_cleanup(struct kimage *image)
143 struct purgatory_info *pi = &image->purgatory_info;
145 vfree(image->kernel_buf);
146 image->kernel_buf = NULL;
148 vfree(image->initrd_buf);
149 image->initrd_buf = NULL;
151 kfree(image->cmdline_buf);
152 image->cmdline_buf = NULL;
154 vfree(pi->purgatory_buf);
155 pi->purgatory_buf = NULL;
160 /* See if architecture has anything to cleanup post load */
161 arch_kimage_file_post_load_cleanup(image);
164 * Above call should have called into bootloader to free up
165 * any data stored in kimage->image_loader_data. It should
166 * be ok now to free it up.
168 kfree(image->image_loader_data);
169 image->image_loader_data = NULL;
173 * In file mode list of segments is prepared by kernel. Copy relevant
174 * data from user space, do error checking, prepare segment list
177 kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
178 const char __user *cmdline_ptr,
179 unsigned long cmdline_len, unsigned flags)
184 ret = copy_file_from_fd(kernel_fd, &image->kernel_buf,
185 &image->kernel_buf_len);
189 /* Call arch image probe handlers */
190 ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
191 image->kernel_buf_len);
196 #ifdef CONFIG_KEXEC_VERIFY_SIG
197 ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf,
198 image->kernel_buf_len);
200 pr_debug("kernel signature verification failed.\n");
203 pr_debug("kernel signature verification successful.\n");
205 /* It is possible that there no initramfs is being loaded */
206 if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
207 ret = copy_file_from_fd(initrd_fd, &image->initrd_buf,
208 &image->initrd_buf_len);
214 image->cmdline_buf = kzalloc(cmdline_len, GFP_KERNEL);
215 if (!image->cmdline_buf) {
220 ret = copy_from_user(image->cmdline_buf, cmdline_ptr,
227 image->cmdline_buf_len = cmdline_len;
229 /* command line should be a string with last byte null */
230 if (image->cmdline_buf[cmdline_len - 1] != '\0') {
236 /* Call arch image load handlers */
237 ldata = arch_kexec_kernel_image_load(image);
240 ret = PTR_ERR(ldata);
244 image->image_loader_data = ldata;
246 /* In case of error, free up all allocated memory in this function */
248 kimage_file_post_load_cleanup(image);
253 kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
254 int initrd_fd, const char __user *cmdline_ptr,
255 unsigned long cmdline_len, unsigned long flags)
258 struct kimage *image;
259 bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
261 image = do_kimage_alloc_init();
265 image->file_mode = 1;
267 if (kexec_on_panic) {
268 /* Enable special crash kernel control page alloc policy. */
269 image->control_page = crashk_res.start;
270 image->type = KEXEC_TYPE_CRASH;
273 ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
274 cmdline_ptr, cmdline_len, flags);
278 ret = sanity_check_segment_list(image);
280 goto out_free_post_load_bufs;
283 image->control_code_page = kimage_alloc_control_pages(image,
284 get_order(KEXEC_CONTROL_PAGE_SIZE));
285 if (!image->control_code_page) {
286 pr_err("Could not allocate control_code_buffer\n");
287 goto out_free_post_load_bufs;
290 if (!kexec_on_panic) {
291 image->swap_page = kimage_alloc_control_pages(image, 0);
292 if (!image->swap_page) {
293 pr_err("Could not allocate swap buffer\n");
294 goto out_free_control_pages;
300 out_free_control_pages:
301 kimage_free_page_list(&image->control_pages);
302 out_free_post_load_bufs:
303 kimage_file_post_load_cleanup(image);
309 SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
310 unsigned long, cmdline_len, const char __user *, cmdline_ptr,
311 unsigned long, flags)
314 struct kimage **dest_image, *image;
316 /* We only trust the superuser with rebooting the system. */
317 if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
320 /* Make sure we have a legal set of flags */
321 if (flags != (flags & KEXEC_FILE_FLAGS))
326 if (!mutex_trylock(&kexec_mutex))
329 dest_image = &kexec_image;
330 if (flags & KEXEC_FILE_ON_CRASH)
331 dest_image = &kexec_crash_image;
333 if (flags & KEXEC_FILE_UNLOAD)
337 * In case of crash, new kernel gets loaded in reserved region. It is
338 * same memory where old crash kernel might be loaded. Free any
339 * current crash dump kernel before we corrupt it.
341 if (flags & KEXEC_FILE_ON_CRASH)
342 kimage_free(xchg(&kexec_crash_image, NULL));
344 ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr,
349 ret = machine_kexec_prepare(image);
353 ret = kexec_calculate_store_digests(image);
357 for (i = 0; i < image->nr_segments; i++) {
358 struct kexec_segment *ksegment;
360 ksegment = &image->segment[i];
361 pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
362 i, ksegment->buf, ksegment->bufsz, ksegment->mem,
365 ret = kimage_load_segment(image, &image->segment[i]);
370 kimage_terminate(image);
373 * Free up any temporary buffers allocated which are not needed
374 * after image has been loaded
376 kimage_file_post_load_cleanup(image);
378 image = xchg(dest_image, image);
380 mutex_unlock(&kexec_mutex);
385 static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
386 struct kexec_buf *kbuf)
388 struct kimage *image = kbuf->image;
389 unsigned long temp_start, temp_end;
391 temp_end = min(end, kbuf->buf_max);
392 temp_start = temp_end - kbuf->memsz;
395 /* align down start */
396 temp_start = temp_start & (~(kbuf->buf_align - 1));
398 if (temp_start < start || temp_start < kbuf->buf_min)
401 temp_end = temp_start + kbuf->memsz - 1;
404 * Make sure this does not conflict with any of existing
407 if (kimage_is_destination_range(image, temp_start, temp_end)) {
408 temp_start = temp_start - PAGE_SIZE;
412 /* We found a suitable memory range */
416 /* If we are here, we found a suitable memory range */
417 kbuf->mem = temp_start;
419 /* Success, stop navigating through remaining System RAM ranges */
423 static int locate_mem_hole_bottom_up(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_start = max(start, kbuf->buf_min);
432 temp_start = ALIGN(temp_start, kbuf->buf_align);
433 temp_end = temp_start + kbuf->memsz - 1;
435 if (temp_end > end || temp_end > kbuf->buf_max)
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_callback(u64 start, u64 end, void *arg)
459 struct kexec_buf *kbuf = (struct kexec_buf *)arg;
460 unsigned long sz = end - start + 1;
462 /* Returning 0 will take to next memory range */
463 if (sz < kbuf->memsz)
466 if (end < kbuf->buf_min || start > kbuf->buf_max)
470 * Allocate memory top down with-in ram range. Otherwise bottom up
474 return locate_mem_hole_top_down(start, end, kbuf);
475 return locate_mem_hole_bottom_up(start, end, kbuf);
479 * Helper function for placing a buffer in a kexec segment. This assumes
480 * that kexec_mutex is held.
482 int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
483 unsigned long memsz, unsigned long buf_align,
484 unsigned long buf_min, unsigned long buf_max,
485 bool top_down, unsigned long *load_addr)
488 struct kexec_segment *ksegment;
489 struct kexec_buf buf, *kbuf;
492 /* Currently adding segment this way is allowed only in file mode */
493 if (!image->file_mode)
496 if (image->nr_segments >= KEXEC_SEGMENT_MAX)
500 * Make sure we are not trying to add buffer after allocating
501 * control pages. All segments need to be placed first before
502 * any control pages are allocated. As control page allocation
503 * logic goes through list of segments to make sure there are
504 * no destination overlaps.
506 if (!list_empty(&image->control_pages)) {
511 memset(&buf, 0, sizeof(struct kexec_buf));
514 kbuf->buffer = buffer;
517 kbuf->memsz = ALIGN(memsz, PAGE_SIZE);
518 kbuf->buf_align = max(buf_align, PAGE_SIZE);
519 kbuf->buf_min = buf_min;
520 kbuf->buf_max = buf_max;
521 kbuf->top_down = top_down;
523 /* Walk the RAM ranges and allocate a suitable range for the buffer */
524 if (image->type == KEXEC_TYPE_CRASH)
525 ret = walk_iomem_res("Crash kernel",
526 IORESOURCE_MEM | IORESOURCE_BUSY,
527 crashk_res.start, crashk_res.end, kbuf,
528 locate_mem_hole_callback);
530 ret = walk_system_ram_res(0, -1, kbuf,
531 locate_mem_hole_callback);
533 /* A suitable memory range could not be found for buffer */
534 return -EADDRNOTAVAIL;
537 /* Found a suitable memory range */
538 ksegment = &image->segment[image->nr_segments];
539 ksegment->kbuf = kbuf->buffer;
540 ksegment->bufsz = kbuf->bufsz;
541 ksegment->mem = kbuf->mem;
542 ksegment->memsz = kbuf->memsz;
543 image->nr_segments++;
544 *load_addr = ksegment->mem;
548 /* Calculate and store the digest of segments */
549 static int kexec_calculate_store_digests(struct kimage *image)
551 struct crypto_shash *tfm;
552 struct shash_desc *desc;
553 int ret = 0, i, j, zero_buf_sz, sha_region_sz;
554 size_t desc_size, nullsz;
557 struct kexec_sha_region *sha_regions;
558 struct purgatory_info *pi = &image->purgatory_info;
560 zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
561 zero_buf_sz = PAGE_SIZE;
563 tfm = crypto_alloc_shash("sha256", 0, 0);
569 desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
570 desc = kzalloc(desc_size, GFP_KERNEL);
576 sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region);
577 sha_regions = vzalloc(sha_region_sz);
586 ret = crypto_shash_init(desc);
588 goto out_free_sha_regions;
590 digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
593 goto out_free_sha_regions;
596 for (j = i = 0; i < image->nr_segments; i++) {
597 struct kexec_segment *ksegment;
599 ksegment = &image->segment[i];
601 * Skip purgatory as it will be modified once we put digest
604 if (ksegment->kbuf == pi->purgatory_buf)
607 ret = crypto_shash_update(desc, ksegment->kbuf,
613 * Assume rest of the buffer is filled with zero and
614 * update digest accordingly.
616 nullsz = ksegment->memsz - ksegment->bufsz;
618 unsigned long bytes = nullsz;
620 if (bytes > zero_buf_sz)
622 ret = crypto_shash_update(desc, zero_buf, bytes);
631 sha_regions[j].start = ksegment->mem;
632 sha_regions[j].len = ksegment->memsz;
637 ret = crypto_shash_final(desc, digest);
639 goto out_free_digest;
640 ret = kexec_purgatory_get_set_symbol(image, "sha_regions",
641 sha_regions, sha_region_sz, 0);
643 goto out_free_digest;
645 ret = kexec_purgatory_get_set_symbol(image, "sha256_digest",
646 digest, SHA256_DIGEST_SIZE, 0);
648 goto out_free_digest;
653 out_free_sha_regions:
663 /* Actually load purgatory. Lot of code taken from kexec-tools */
664 static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
665 unsigned long max, int top_down)
667 struct purgatory_info *pi = &image->purgatory_info;
668 unsigned long align, buf_align, bss_align, buf_sz, bss_sz, bss_pad;
669 unsigned long memsz, entry, load_addr, curr_load_addr, bss_addr, offset;
670 unsigned char *buf_addr, *src;
671 int i, ret = 0, entry_sidx = -1;
672 const Elf_Shdr *sechdrs_c;
673 Elf_Shdr *sechdrs = NULL;
674 void *purgatory_buf = NULL;
677 * sechdrs_c points to section headers in purgatory and are read
678 * only. No modifications allowed.
680 sechdrs_c = (void *)pi->ehdr + pi->ehdr->e_shoff;
683 * We can not modify sechdrs_c[] and its fields. It is read only.
684 * Copy it over to a local copy where one can store some temporary
685 * data and free it at the end. We need to modify ->sh_addr and
686 * ->sh_offset fields to keep track of permanent and temporary
687 * locations of sections.
689 sechdrs = vzalloc(pi->ehdr->e_shnum * sizeof(Elf_Shdr));
693 memcpy(sechdrs, sechdrs_c, pi->ehdr->e_shnum * sizeof(Elf_Shdr));
696 * We seem to have multiple copies of sections. First copy is which
697 * is embedded in kernel in read only section. Some of these sections
698 * will be copied to a temporary buffer and relocated. And these
699 * sections will finally be copied to their final destination at
702 * Use ->sh_offset to reflect section address in memory. It will
703 * point to original read only copy if section is not allocatable.
704 * Otherwise it will point to temporary copy which will be relocated.
706 * Use ->sh_addr to contain final address of the section where it
707 * will go during execution time.
709 for (i = 0; i < pi->ehdr->e_shnum; i++) {
710 if (sechdrs[i].sh_type == SHT_NOBITS)
713 sechdrs[i].sh_offset = (unsigned long)pi->ehdr +
714 sechdrs[i].sh_offset;
718 * Identify entry point section and make entry relative to section
721 entry = pi->ehdr->e_entry;
722 for (i = 0; i < pi->ehdr->e_shnum; i++) {
723 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
726 if (!(sechdrs[i].sh_flags & SHF_EXECINSTR))
729 /* Make entry section relative */
730 if (sechdrs[i].sh_addr <= pi->ehdr->e_entry &&
731 ((sechdrs[i].sh_addr + sechdrs[i].sh_size) >
732 pi->ehdr->e_entry)) {
734 entry -= sechdrs[i].sh_addr;
739 /* Determine how much memory is needed to load relocatable object. */
745 for (i = 0; i < pi->ehdr->e_shnum; i++) {
746 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
749 align = sechdrs[i].sh_addralign;
750 if (sechdrs[i].sh_type != SHT_NOBITS) {
751 if (buf_align < align)
753 buf_sz = ALIGN(buf_sz, align);
754 buf_sz += sechdrs[i].sh_size;
757 if (bss_align < align)
759 bss_sz = ALIGN(bss_sz, align);
760 bss_sz += sechdrs[i].sh_size;
764 /* Determine the bss padding required to align bss properly */
766 if (buf_sz & (bss_align - 1))
767 bss_pad = bss_align - (buf_sz & (bss_align - 1));
769 memsz = buf_sz + bss_pad + bss_sz;
771 /* Allocate buffer for purgatory */
772 purgatory_buf = vzalloc(buf_sz);
773 if (!purgatory_buf) {
778 if (buf_align < bss_align)
779 buf_align = bss_align;
781 /* Add buffer to segment list */
782 ret = kexec_add_buffer(image, purgatory_buf, buf_sz, memsz,
783 buf_align, min, max, top_down,
784 &pi->purgatory_load_addr);
788 /* Load SHF_ALLOC sections */
789 buf_addr = purgatory_buf;
790 load_addr = curr_load_addr = pi->purgatory_load_addr;
791 bss_addr = load_addr + buf_sz + bss_pad;
793 for (i = 0; i < pi->ehdr->e_shnum; i++) {
794 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
797 align = sechdrs[i].sh_addralign;
798 if (sechdrs[i].sh_type != SHT_NOBITS) {
799 curr_load_addr = ALIGN(curr_load_addr, align);
800 offset = curr_load_addr - load_addr;
801 /* We already modifed ->sh_offset to keep src addr */
802 src = (char *) sechdrs[i].sh_offset;
803 memcpy(buf_addr + offset, src, sechdrs[i].sh_size);
805 /* Store load address and source address of section */
806 sechdrs[i].sh_addr = curr_load_addr;
809 * This section got copied to temporary buffer. Update
810 * ->sh_offset accordingly.
812 sechdrs[i].sh_offset = (unsigned long)(buf_addr + offset);
814 /* Advance to the next address */
815 curr_load_addr += sechdrs[i].sh_size;
817 bss_addr = ALIGN(bss_addr, align);
818 sechdrs[i].sh_addr = bss_addr;
819 bss_addr += sechdrs[i].sh_size;
823 /* Update entry point based on load address of text section */
825 entry += sechdrs[entry_sidx].sh_addr;
827 /* Make kernel jump to purgatory after shutdown */
828 image->start = entry;
830 /* Used later to get/set symbol values */
831 pi->sechdrs = sechdrs;
834 * Used later to identify which section is purgatory and skip it
837 pi->purgatory_buf = purgatory_buf;
841 vfree(purgatory_buf);
845 static int kexec_apply_relocations(struct kimage *image)
848 struct purgatory_info *pi = &image->purgatory_info;
849 Elf_Shdr *sechdrs = pi->sechdrs;
851 /* Apply relocations */
852 for (i = 0; i < pi->ehdr->e_shnum; i++) {
853 Elf_Shdr *section, *symtab;
855 if (sechdrs[i].sh_type != SHT_RELA &&
856 sechdrs[i].sh_type != SHT_REL)
860 * For section of type SHT_RELA/SHT_REL,
861 * ->sh_link contains section header index of associated
862 * symbol table. And ->sh_info contains section header
863 * index of section to which relocations apply.
865 if (sechdrs[i].sh_info >= pi->ehdr->e_shnum ||
866 sechdrs[i].sh_link >= pi->ehdr->e_shnum)
869 section = &sechdrs[sechdrs[i].sh_info];
870 symtab = &sechdrs[sechdrs[i].sh_link];
872 if (!(section->sh_flags & SHF_ALLOC))
876 * symtab->sh_link contain section header index of associated
879 if (symtab->sh_link >= pi->ehdr->e_shnum)
880 /* Invalid section number? */
884 * Respective architecture needs to provide support for applying
885 * relocations of type SHT_RELA/SHT_REL.
887 if (sechdrs[i].sh_type == SHT_RELA)
888 ret = arch_kexec_apply_relocations_add(pi->ehdr,
890 else if (sechdrs[i].sh_type == SHT_REL)
891 ret = arch_kexec_apply_relocations(pi->ehdr,
900 /* Load relocatable purgatory object and relocate it appropriately */
901 int kexec_load_purgatory(struct kimage *image, unsigned long min,
902 unsigned long max, int top_down,
903 unsigned long *load_addr)
905 struct purgatory_info *pi = &image->purgatory_info;
908 if (kexec_purgatory_size <= 0)
911 if (kexec_purgatory_size < sizeof(Elf_Ehdr))
914 pi->ehdr = (Elf_Ehdr *)kexec_purgatory;
916 if (memcmp(pi->ehdr->e_ident, ELFMAG, SELFMAG) != 0
917 || pi->ehdr->e_type != ET_REL
918 || !elf_check_arch(pi->ehdr)
919 || pi->ehdr->e_shentsize != sizeof(Elf_Shdr))
922 if (pi->ehdr->e_shoff >= kexec_purgatory_size
923 || (pi->ehdr->e_shnum * sizeof(Elf_Shdr) >
924 kexec_purgatory_size - pi->ehdr->e_shoff))
927 ret = __kexec_load_purgatory(image, min, max, top_down);
931 ret = kexec_apply_relocations(image);
935 *load_addr = pi->purgatory_load_addr;
941 vfree(pi->purgatory_buf);
942 pi->purgatory_buf = NULL;
946 static Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
955 if (!pi->sechdrs || !pi->ehdr)
958 sechdrs = pi->sechdrs;
961 for (i = 0; i < ehdr->e_shnum; i++) {
962 if (sechdrs[i].sh_type != SHT_SYMTAB)
965 if (sechdrs[i].sh_link >= ehdr->e_shnum)
966 /* Invalid strtab section number */
968 strtab = (char *)sechdrs[sechdrs[i].sh_link].sh_offset;
969 syms = (Elf_Sym *)sechdrs[i].sh_offset;
971 /* Go through symbols for a match */
972 for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
973 if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
976 if (strcmp(strtab + syms[k].st_name, name) != 0)
979 if (syms[k].st_shndx == SHN_UNDEF ||
980 syms[k].st_shndx >= ehdr->e_shnum) {
981 pr_debug("Symbol: %s has bad section index %d.\n",
982 name, syms[k].st_shndx);
986 /* Found the symbol we are looking for */
994 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
996 struct purgatory_info *pi = &image->purgatory_info;
1000 sym = kexec_purgatory_find_symbol(pi, name);
1002 return ERR_PTR(-EINVAL);
1004 sechdr = &pi->sechdrs[sym->st_shndx];
1007 * Returns the address where symbol will finally be loaded after
1008 * kexec_load_segment()
1010 return (void *)(sechdr->sh_addr + sym->st_value);
1014 * Get or set value of a symbol. If "get_value" is true, symbol value is
1015 * returned in buf otherwise symbol value is set based on value in buf.
1017 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
1018 void *buf, unsigned int size, bool get_value)
1022 struct purgatory_info *pi = &image->purgatory_info;
1025 sym = kexec_purgatory_find_symbol(pi, name);
1029 if (sym->st_size != size) {
1030 pr_err("symbol %s size mismatch: expected %lu actual %u\n",
1031 name, (unsigned long)sym->st_size, size);
1035 sechdrs = pi->sechdrs;
1037 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
1038 pr_err("symbol %s is in a bss section. Cannot %s\n", name,
1039 get_value ? "get" : "set");
1043 sym_buf = (unsigned char *)sechdrs[sym->st_shndx].sh_offset +
1047 memcpy((void *)buf, sym_buf, size);
1049 memcpy((void *)sym_buf, buf, size);