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/syscalls.h>
28 #include <linux/vmalloc.h>
29 #include "kexec_internal.h"
31 static int kexec_calculate_store_digests(struct kimage
*image
);
34 * Currently this is the only default function that is exported as some
35 * architectures need it to do additional handlings.
36 * In the future, other default functions may be exported too if required.
38 int kexec_image_probe_default(struct kimage
*image
, void *buf
,
39 unsigned long buf_len
)
41 const struct kexec_file_ops
* const *fops
;
44 for (fops
= &kexec_file_loaders
[0]; *fops
&& (*fops
)->probe
; ++fops
) {
45 ret
= (*fops
)->probe(buf
, buf_len
);
55 /* Architectures can provide this probe function */
56 int __weak
arch_kexec_kernel_image_probe(struct kimage
*image
, void *buf
,
57 unsigned long buf_len
)
59 return kexec_image_probe_default(image
, buf
, buf_len
);
62 static void *kexec_image_load_default(struct kimage
*image
)
64 if (!image
->fops
|| !image
->fops
->load
)
65 return ERR_PTR(-ENOEXEC
);
67 return image
->fops
->load(image
, image
->kernel_buf
,
68 image
->kernel_buf_len
, image
->initrd_buf
,
69 image
->initrd_buf_len
, image
->cmdline_buf
,
70 image
->cmdline_buf_len
);
73 void * __weak
arch_kexec_kernel_image_load(struct kimage
*image
)
75 return kexec_image_load_default(image
);
78 int kexec_image_post_load_cleanup_default(struct kimage
*image
)
80 if (!image
->fops
|| !image
->fops
->cleanup
)
83 return image
->fops
->cleanup(image
->image_loader_data
);
86 int __weak
arch_kimage_file_post_load_cleanup(struct kimage
*image
)
88 return kexec_image_post_load_cleanup_default(image
);
91 #ifdef CONFIG_KEXEC_SIG
92 static int kexec_image_verify_sig_default(struct kimage
*image
, void *buf
,
93 unsigned long buf_len
)
95 if (!image
->fops
|| !image
->fops
->verify_sig
) {
96 pr_debug("kernel loader does not support signature verification.\n");
100 return image
->fops
->verify_sig(buf
, buf_len
);
103 int __weak
arch_kexec_kernel_verify_sig(struct kimage
*image
, void *buf
,
104 unsigned long buf_len
)
106 return kexec_image_verify_sig_default(image
, buf
, buf_len
);
111 * arch_kexec_apply_relocations_add - apply relocations of type RELA
112 * @pi: Purgatory to be relocated.
113 * @section: Section relocations applying to.
114 * @relsec: Section containing RELAs.
115 * @symtab: Corresponding symtab.
117 * Return: 0 on success, negative errno on error.
120 arch_kexec_apply_relocations_add(struct purgatory_info
*pi
, Elf_Shdr
*section
,
121 const Elf_Shdr
*relsec
, const Elf_Shdr
*symtab
)
123 pr_err("RELA relocation unsupported.\n");
128 * arch_kexec_apply_relocations - apply relocations of type REL
129 * @pi: Purgatory to be relocated.
130 * @section: Section relocations applying to.
131 * @relsec: Section containing RELs.
132 * @symtab: Corresponding symtab.
134 * Return: 0 on success, negative errno on error.
137 arch_kexec_apply_relocations(struct purgatory_info
*pi
, Elf_Shdr
*section
,
138 const Elf_Shdr
*relsec
, const Elf_Shdr
*symtab
)
140 pr_err("REL relocation unsupported.\n");
145 * Free up memory used by kernel, initrd, and command line. This is temporary
146 * memory allocation which is not needed any more after these buffers have
147 * been loaded into separate segments and have been copied elsewhere.
149 void kimage_file_post_load_cleanup(struct kimage
*image
)
151 struct purgatory_info
*pi
= &image
->purgatory_info
;
153 vfree(image
->kernel_buf
);
154 image
->kernel_buf
= NULL
;
156 vfree(image
->initrd_buf
);
157 image
->initrd_buf
= NULL
;
159 kfree(image
->cmdline_buf
);
160 image
->cmdline_buf
= NULL
;
162 vfree(pi
->purgatory_buf
);
163 pi
->purgatory_buf
= NULL
;
168 /* See if architecture has anything to cleanup post load */
169 arch_kimage_file_post_load_cleanup(image
);
172 * Above call should have called into bootloader to free up
173 * any data stored in kimage->image_loader_data. It should
174 * be ok now to free it up.
176 kfree(image
->image_loader_data
);
177 image
->image_loader_data
= NULL
;
180 #ifdef CONFIG_KEXEC_SIG
182 kimage_validate_signature(struct kimage
*image
)
186 ret
= arch_kexec_kernel_verify_sig(image
, image
->kernel_buf
,
187 image
->kernel_buf_len
);
190 if (IS_ENABLED(CONFIG_KEXEC_SIG_FORCE
)) {
191 pr_notice("Enforced kernel signature verification failed (%d).\n", ret
);
196 * If IMA is guaranteed to appraise a signature on the kexec
197 * image, permit it even if the kernel is otherwise locked
200 if (!ima_appraise_signature(READING_KEXEC_IMAGE
) &&
201 security_locked_down(LOCKDOWN_KEXEC
))
204 pr_debug("kernel signature verification failed (%d).\n", ret
);
212 * In file mode list of segments is prepared by kernel. Copy relevant
213 * data from user space, do error checking, prepare segment list
216 kimage_file_prepare_segments(struct kimage
*image
, int kernel_fd
, int initrd_fd
,
217 const char __user
*cmdline_ptr
,
218 unsigned long cmdline_len
, unsigned flags
)
224 ret
= kernel_read_file_from_fd(kernel_fd
, &image
->kernel_buf
,
225 &size
, INT_MAX
, READING_KEXEC_IMAGE
);
228 image
->kernel_buf_len
= size
;
230 /* Call arch image probe handlers */
231 ret
= arch_kexec_kernel_image_probe(image
, image
->kernel_buf
,
232 image
->kernel_buf_len
);
236 #ifdef CONFIG_KEXEC_SIG
237 ret
= kimage_validate_signature(image
);
242 /* It is possible that there no initramfs is being loaded */
243 if (!(flags
& KEXEC_FILE_NO_INITRAMFS
)) {
244 ret
= kernel_read_file_from_fd(initrd_fd
, &image
->initrd_buf
,
246 READING_KEXEC_INITRAMFS
);
249 image
->initrd_buf_len
= size
;
253 image
->cmdline_buf
= memdup_user(cmdline_ptr
, cmdline_len
);
254 if (IS_ERR(image
->cmdline_buf
)) {
255 ret
= PTR_ERR(image
->cmdline_buf
);
256 image
->cmdline_buf
= NULL
;
260 image
->cmdline_buf_len
= cmdline_len
;
262 /* command line should be a string with last byte null */
263 if (image
->cmdline_buf
[cmdline_len
- 1] != '\0') {
268 ima_kexec_cmdline(image
->cmdline_buf
,
269 image
->cmdline_buf_len
- 1);
272 /* IMA needs to pass the measurement list to the next kernel. */
273 ima_add_kexec_buffer(image
);
275 /* Call arch image load handlers */
276 ldata
= arch_kexec_kernel_image_load(image
);
279 ret
= PTR_ERR(ldata
);
283 image
->image_loader_data
= ldata
;
285 /* In case of error, free up all allocated memory in this function */
287 kimage_file_post_load_cleanup(image
);
292 kimage_file_alloc_init(struct kimage
**rimage
, int kernel_fd
,
293 int initrd_fd
, const char __user
*cmdline_ptr
,
294 unsigned long cmdline_len
, unsigned long flags
)
297 struct kimage
*image
;
298 bool kexec_on_panic
= flags
& KEXEC_FILE_ON_CRASH
;
300 image
= do_kimage_alloc_init();
304 image
->file_mode
= 1;
306 if (kexec_on_panic
) {
307 /* Enable special crash kernel control page alloc policy. */
308 image
->control_page
= crashk_res
.start
;
309 image
->type
= KEXEC_TYPE_CRASH
;
312 ret
= kimage_file_prepare_segments(image
, kernel_fd
, initrd_fd
,
313 cmdline_ptr
, cmdline_len
, flags
);
317 ret
= sanity_check_segment_list(image
);
319 goto out_free_post_load_bufs
;
322 image
->control_code_page
= kimage_alloc_control_pages(image
,
323 get_order(KEXEC_CONTROL_PAGE_SIZE
));
324 if (!image
->control_code_page
) {
325 pr_err("Could not allocate control_code_buffer\n");
326 goto out_free_post_load_bufs
;
329 if (!kexec_on_panic
) {
330 image
->swap_page
= kimage_alloc_control_pages(image
, 0);
331 if (!image
->swap_page
) {
332 pr_err("Could not allocate swap buffer\n");
333 goto out_free_control_pages
;
339 out_free_control_pages
:
340 kimage_free_page_list(&image
->control_pages
);
341 out_free_post_load_bufs
:
342 kimage_file_post_load_cleanup(image
);
348 SYSCALL_DEFINE5(kexec_file_load
, int, kernel_fd
, int, initrd_fd
,
349 unsigned long, cmdline_len
, const char __user
*, cmdline_ptr
,
350 unsigned long, flags
)
353 struct kimage
**dest_image
, *image
;
355 /* We only trust the superuser with rebooting the system. */
356 if (!capable(CAP_SYS_BOOT
) || kexec_load_disabled
)
359 /* Make sure we have a legal set of flags */
360 if (flags
!= (flags
& KEXEC_FILE_FLAGS
))
365 if (!mutex_trylock(&kexec_mutex
))
368 dest_image
= &kexec_image
;
369 if (flags
& KEXEC_FILE_ON_CRASH
) {
370 dest_image
= &kexec_crash_image
;
371 if (kexec_crash_image
)
372 arch_kexec_unprotect_crashkres();
375 if (flags
& KEXEC_FILE_UNLOAD
)
379 * In case of crash, new kernel gets loaded in reserved region. It is
380 * same memory where old crash kernel might be loaded. Free any
381 * current crash dump kernel before we corrupt it.
383 if (flags
& KEXEC_FILE_ON_CRASH
)
384 kimage_free(xchg(&kexec_crash_image
, NULL
));
386 ret
= kimage_file_alloc_init(&image
, kernel_fd
, initrd_fd
, cmdline_ptr
,
391 ret
= machine_kexec_prepare(image
);
396 * Some architecture(like S390) may touch the crash memory before
397 * machine_kexec_prepare(), we must copy vmcoreinfo data after it.
399 ret
= kimage_crash_copy_vmcoreinfo(image
);
403 ret
= kexec_calculate_store_digests(image
);
407 for (i
= 0; i
< image
->nr_segments
; i
++) {
408 struct kexec_segment
*ksegment
;
410 ksegment
= &image
->segment
[i
];
411 pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
412 i
, ksegment
->buf
, ksegment
->bufsz
, ksegment
->mem
,
415 ret
= kimage_load_segment(image
, &image
->segment
[i
]);
420 kimage_terminate(image
);
422 ret
= machine_kexec_post_load(image
);
427 * Free up any temporary buffers allocated which are not needed
428 * after image has been loaded
430 kimage_file_post_load_cleanup(image
);
432 image
= xchg(dest_image
, image
);
434 if ((flags
& KEXEC_FILE_ON_CRASH
) && kexec_crash_image
)
435 arch_kexec_protect_crashkres();
437 mutex_unlock(&kexec_mutex
);
442 static int locate_mem_hole_top_down(unsigned long start
, unsigned long end
,
443 struct kexec_buf
*kbuf
)
445 struct kimage
*image
= kbuf
->image
;
446 unsigned long temp_start
, temp_end
;
448 temp_end
= min(end
, kbuf
->buf_max
);
449 temp_start
= temp_end
- kbuf
->memsz
;
452 /* align down start */
453 temp_start
= temp_start
& (~(kbuf
->buf_align
- 1));
455 if (temp_start
< start
|| temp_start
< kbuf
->buf_min
)
458 temp_end
= temp_start
+ kbuf
->memsz
- 1;
461 * Make sure this does not conflict with any of existing
464 if (kimage_is_destination_range(image
, temp_start
, temp_end
)) {
465 temp_start
= temp_start
- PAGE_SIZE
;
469 /* We found a suitable memory range */
473 /* If we are here, we found a suitable memory range */
474 kbuf
->mem
= temp_start
;
476 /* Success, stop navigating through remaining System RAM ranges */
480 static int locate_mem_hole_bottom_up(unsigned long start
, unsigned long end
,
481 struct kexec_buf
*kbuf
)
483 struct kimage
*image
= kbuf
->image
;
484 unsigned long temp_start
, temp_end
;
486 temp_start
= max(start
, kbuf
->buf_min
);
489 temp_start
= ALIGN(temp_start
, kbuf
->buf_align
);
490 temp_end
= temp_start
+ kbuf
->memsz
- 1;
492 if (temp_end
> end
|| temp_end
> kbuf
->buf_max
)
495 * Make sure this does not conflict with any of existing
498 if (kimage_is_destination_range(image
, temp_start
, temp_end
)) {
499 temp_start
= temp_start
+ PAGE_SIZE
;
503 /* We found a suitable memory range */
507 /* If we are here, we found a suitable memory range */
508 kbuf
->mem
= temp_start
;
510 /* Success, stop navigating through remaining System RAM ranges */
514 static int locate_mem_hole_callback(struct resource
*res
, void *arg
)
516 struct kexec_buf
*kbuf
= (struct kexec_buf
*)arg
;
517 u64 start
= res
->start
, end
= res
->end
;
518 unsigned long sz
= end
- start
+ 1;
520 /* Returning 0 will take to next memory range */
522 /* Don't use memory that will be detected and handled by a driver. */
523 if (res
->flags
& IORESOURCE_MEM_DRIVER_MANAGED
)
526 if (sz
< kbuf
->memsz
)
529 if (end
< kbuf
->buf_min
|| start
> kbuf
->buf_max
)
533 * Allocate memory top down with-in ram range. Otherwise bottom up
537 return locate_mem_hole_top_down(start
, end
, kbuf
);
538 return locate_mem_hole_bottom_up(start
, end
, kbuf
);
541 #ifdef CONFIG_ARCH_KEEP_MEMBLOCK
542 static int kexec_walk_memblock(struct kexec_buf
*kbuf
,
543 int (*func
)(struct resource
*, void *))
547 phys_addr_t mstart
, mend
;
548 struct resource res
= { };
550 if (kbuf
->image
->type
== KEXEC_TYPE_CRASH
)
551 return func(&crashk_res
, kbuf
);
553 if (kbuf
->top_down
) {
554 for_each_free_mem_range_reverse(i
, NUMA_NO_NODE
, MEMBLOCK_NONE
,
555 &mstart
, &mend
, NULL
) {
557 * In memblock, end points to the first byte after the
558 * range while in kexec, end points to the last byte
563 ret
= func(&res
, kbuf
);
568 for_each_free_mem_range(i
, NUMA_NO_NODE
, MEMBLOCK_NONE
,
569 &mstart
, &mend
, NULL
) {
571 * In memblock, end points to the first byte after the
572 * range while in kexec, end points to the last byte
577 ret
= func(&res
, kbuf
);
586 static int kexec_walk_memblock(struct kexec_buf
*kbuf
,
587 int (*func
)(struct resource
*, void *))
594 * kexec_walk_resources - call func(data) on free memory regions
595 * @kbuf: Context info for the search. Also passed to @func.
596 * @func: Function to call for each memory region.
598 * Return: The memory walk will stop when func returns a non-zero value
599 * and that value will be returned. If all free regions are visited without
600 * func returning non-zero, then zero will be returned.
602 static int kexec_walk_resources(struct kexec_buf
*kbuf
,
603 int (*func
)(struct resource
*, void *))
605 if (kbuf
->image
->type
== KEXEC_TYPE_CRASH
)
606 return walk_iomem_res_desc(crashk_res
.desc
,
607 IORESOURCE_SYSTEM_RAM
| IORESOURCE_BUSY
,
608 crashk_res
.start
, crashk_res
.end
,
611 return walk_system_ram_res(0, ULONG_MAX
, kbuf
, func
);
615 * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
616 * @kbuf: Parameters for the memory search.
618 * On success, kbuf->mem will have the start address of the memory region found.
620 * Return: 0 on success, negative errno on error.
622 int kexec_locate_mem_hole(struct kexec_buf
*kbuf
)
626 /* Arch knows where to place */
627 if (kbuf
->mem
!= KEXEC_BUF_MEM_UNKNOWN
)
630 if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK
))
631 ret
= kexec_walk_resources(kbuf
, locate_mem_hole_callback
);
633 ret
= kexec_walk_memblock(kbuf
, locate_mem_hole_callback
);
635 return ret
== 1 ? 0 : -EADDRNOTAVAIL
;
639 * kexec_add_buffer - place a buffer in a kexec segment
640 * @kbuf: Buffer contents and memory parameters.
642 * This function assumes that kexec_mutex is held.
643 * On successful return, @kbuf->mem will have the physical address of
644 * the buffer in memory.
646 * Return: 0 on success, negative errno on error.
648 int kexec_add_buffer(struct kexec_buf
*kbuf
)
651 struct kexec_segment
*ksegment
;
654 /* Currently adding segment this way is allowed only in file mode */
655 if (!kbuf
->image
->file_mode
)
658 if (kbuf
->image
->nr_segments
>= KEXEC_SEGMENT_MAX
)
662 * Make sure we are not trying to add buffer after allocating
663 * control pages. All segments need to be placed first before
664 * any control pages are allocated. As control page allocation
665 * logic goes through list of segments to make sure there are
666 * no destination overlaps.
668 if (!list_empty(&kbuf
->image
->control_pages
)) {
673 /* Ensure minimum alignment needed for segments. */
674 kbuf
->memsz
= ALIGN(kbuf
->memsz
, PAGE_SIZE
);
675 kbuf
->buf_align
= max(kbuf
->buf_align
, PAGE_SIZE
);
677 /* Walk the RAM ranges and allocate a suitable range for the buffer */
678 ret
= kexec_locate_mem_hole(kbuf
);
682 /* Found a suitable memory range */
683 ksegment
= &kbuf
->image
->segment
[kbuf
->image
->nr_segments
];
684 ksegment
->kbuf
= kbuf
->buffer
;
685 ksegment
->bufsz
= kbuf
->bufsz
;
686 ksegment
->mem
= kbuf
->mem
;
687 ksegment
->memsz
= kbuf
->memsz
;
688 kbuf
->image
->nr_segments
++;
692 /* Calculate and store the digest of segments */
693 static int kexec_calculate_store_digests(struct kimage
*image
)
695 struct crypto_shash
*tfm
;
696 struct shash_desc
*desc
;
697 int ret
= 0, i
, j
, zero_buf_sz
, sha_region_sz
;
698 size_t desc_size
, nullsz
;
701 struct kexec_sha_region
*sha_regions
;
702 struct purgatory_info
*pi
= &image
->purgatory_info
;
704 if (!IS_ENABLED(CONFIG_ARCH_HAS_KEXEC_PURGATORY
))
707 zero_buf
= __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT
);
708 zero_buf_sz
= PAGE_SIZE
;
710 tfm
= crypto_alloc_shash("sha256", 0, 0);
716 desc_size
= crypto_shash_descsize(tfm
) + sizeof(*desc
);
717 desc
= kzalloc(desc_size
, GFP_KERNEL
);
723 sha_region_sz
= KEXEC_SEGMENT_MAX
* sizeof(struct kexec_sha_region
);
724 sha_regions
= vzalloc(sha_region_sz
);
730 ret
= crypto_shash_init(desc
);
732 goto out_free_sha_regions
;
734 digest
= kzalloc(SHA256_DIGEST_SIZE
, GFP_KERNEL
);
737 goto out_free_sha_regions
;
740 for (j
= i
= 0; i
< image
->nr_segments
; i
++) {
741 struct kexec_segment
*ksegment
;
743 ksegment
= &image
->segment
[i
];
745 * Skip purgatory as it will be modified once we put digest
748 if (ksegment
->kbuf
== pi
->purgatory_buf
)
751 ret
= crypto_shash_update(desc
, ksegment
->kbuf
,
757 * Assume rest of the buffer is filled with zero and
758 * update digest accordingly.
760 nullsz
= ksegment
->memsz
- ksegment
->bufsz
;
762 unsigned long bytes
= nullsz
;
764 if (bytes
> zero_buf_sz
)
766 ret
= crypto_shash_update(desc
, zero_buf
, bytes
);
775 sha_regions
[j
].start
= ksegment
->mem
;
776 sha_regions
[j
].len
= ksegment
->memsz
;
781 ret
= crypto_shash_final(desc
, digest
);
783 goto out_free_digest
;
784 ret
= kexec_purgatory_get_set_symbol(image
, "purgatory_sha_regions",
785 sha_regions
, sha_region_sz
, 0);
787 goto out_free_digest
;
789 ret
= kexec_purgatory_get_set_symbol(image
, "purgatory_sha256_digest",
790 digest
, SHA256_DIGEST_SIZE
, 0);
792 goto out_free_digest
;
797 out_free_sha_regions
:
807 #ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY
809 * kexec_purgatory_setup_kbuf - prepare buffer to load purgatory.
810 * @pi: Purgatory to be loaded.
811 * @kbuf: Buffer to setup.
813 * Allocates the memory needed for the buffer. Caller is responsible to free
814 * the memory after use.
816 * Return: 0 on success, negative errno on error.
818 static int kexec_purgatory_setup_kbuf(struct purgatory_info
*pi
,
819 struct kexec_buf
*kbuf
)
821 const Elf_Shdr
*sechdrs
;
822 unsigned long bss_align
;
823 unsigned long bss_sz
;
827 sechdrs
= (void *)pi
->ehdr
+ pi
->ehdr
->e_shoff
;
828 kbuf
->buf_align
= bss_align
= 1;
829 kbuf
->bufsz
= bss_sz
= 0;
831 for (i
= 0; i
< pi
->ehdr
->e_shnum
; i
++) {
832 if (!(sechdrs
[i
].sh_flags
& SHF_ALLOC
))
835 align
= sechdrs
[i
].sh_addralign
;
836 if (sechdrs
[i
].sh_type
!= SHT_NOBITS
) {
837 if (kbuf
->buf_align
< align
)
838 kbuf
->buf_align
= align
;
839 kbuf
->bufsz
= ALIGN(kbuf
->bufsz
, align
);
840 kbuf
->bufsz
+= sechdrs
[i
].sh_size
;
842 if (bss_align
< align
)
844 bss_sz
= ALIGN(bss_sz
, align
);
845 bss_sz
+= sechdrs
[i
].sh_size
;
848 kbuf
->bufsz
= ALIGN(kbuf
->bufsz
, bss_align
);
849 kbuf
->memsz
= kbuf
->bufsz
+ bss_sz
;
850 if (kbuf
->buf_align
< bss_align
)
851 kbuf
->buf_align
= bss_align
;
853 kbuf
->buffer
= vzalloc(kbuf
->bufsz
);
856 pi
->purgatory_buf
= kbuf
->buffer
;
858 ret
= kexec_add_buffer(kbuf
);
864 vfree(pi
->purgatory_buf
);
865 pi
->purgatory_buf
= NULL
;
870 * kexec_purgatory_setup_sechdrs - prepares the pi->sechdrs buffer.
871 * @pi: Purgatory to be loaded.
872 * @kbuf: Buffer prepared to store purgatory.
874 * Allocates the memory needed for the buffer. Caller is responsible to free
875 * the memory after use.
877 * Return: 0 on success, negative errno on error.
879 static int kexec_purgatory_setup_sechdrs(struct purgatory_info
*pi
,
880 struct kexec_buf
*kbuf
)
882 unsigned long bss_addr
;
883 unsigned long offset
;
888 * The section headers in kexec_purgatory are read-only. In order to
889 * have them modifiable make a temporary copy.
891 sechdrs
= vzalloc(array_size(sizeof(Elf_Shdr
), pi
->ehdr
->e_shnum
));
894 memcpy(sechdrs
, (void *)pi
->ehdr
+ pi
->ehdr
->e_shoff
,
895 pi
->ehdr
->e_shnum
* sizeof(Elf_Shdr
));
896 pi
->sechdrs
= sechdrs
;
899 bss_addr
= kbuf
->mem
+ kbuf
->bufsz
;
900 kbuf
->image
->start
= pi
->ehdr
->e_entry
;
902 for (i
= 0; i
< pi
->ehdr
->e_shnum
; i
++) {
906 if (!(sechdrs
[i
].sh_flags
& SHF_ALLOC
))
909 align
= sechdrs
[i
].sh_addralign
;
910 if (sechdrs
[i
].sh_type
== SHT_NOBITS
) {
911 bss_addr
= ALIGN(bss_addr
, align
);
912 sechdrs
[i
].sh_addr
= bss_addr
;
913 bss_addr
+= sechdrs
[i
].sh_size
;
917 offset
= ALIGN(offset
, align
);
918 if (sechdrs
[i
].sh_flags
& SHF_EXECINSTR
&&
919 pi
->ehdr
->e_entry
>= sechdrs
[i
].sh_addr
&&
920 pi
->ehdr
->e_entry
< (sechdrs
[i
].sh_addr
921 + sechdrs
[i
].sh_size
)) {
922 kbuf
->image
->start
-= sechdrs
[i
].sh_addr
;
923 kbuf
->image
->start
+= kbuf
->mem
+ offset
;
926 src
= (void *)pi
->ehdr
+ sechdrs
[i
].sh_offset
;
927 dst
= pi
->purgatory_buf
+ offset
;
928 memcpy(dst
, src
, sechdrs
[i
].sh_size
);
930 sechdrs
[i
].sh_addr
= kbuf
->mem
+ offset
;
931 sechdrs
[i
].sh_offset
= offset
;
932 offset
+= sechdrs
[i
].sh_size
;
938 static int kexec_apply_relocations(struct kimage
*image
)
941 struct purgatory_info
*pi
= &image
->purgatory_info
;
942 const Elf_Shdr
*sechdrs
;
944 sechdrs
= (void *)pi
->ehdr
+ pi
->ehdr
->e_shoff
;
946 for (i
= 0; i
< pi
->ehdr
->e_shnum
; i
++) {
947 const Elf_Shdr
*relsec
;
948 const Elf_Shdr
*symtab
;
951 relsec
= sechdrs
+ i
;
953 if (relsec
->sh_type
!= SHT_RELA
&&
954 relsec
->sh_type
!= SHT_REL
)
958 * For section of type SHT_RELA/SHT_REL,
959 * ->sh_link contains section header index of associated
960 * symbol table. And ->sh_info contains section header
961 * index of section to which relocations apply.
963 if (relsec
->sh_info
>= pi
->ehdr
->e_shnum
||
964 relsec
->sh_link
>= pi
->ehdr
->e_shnum
)
967 section
= pi
->sechdrs
+ relsec
->sh_info
;
968 symtab
= sechdrs
+ relsec
->sh_link
;
970 if (!(section
->sh_flags
& SHF_ALLOC
))
974 * symtab->sh_link contain section header index of associated
977 if (symtab
->sh_link
>= pi
->ehdr
->e_shnum
)
978 /* Invalid section number? */
982 * Respective architecture needs to provide support for applying
983 * relocations of type SHT_RELA/SHT_REL.
985 if (relsec
->sh_type
== SHT_RELA
)
986 ret
= arch_kexec_apply_relocations_add(pi
, section
,
988 else if (relsec
->sh_type
== SHT_REL
)
989 ret
= arch_kexec_apply_relocations(pi
, section
,
999 * kexec_load_purgatory - Load and relocate the purgatory object.
1000 * @image: Image to add the purgatory to.
1001 * @kbuf: Memory parameters to use.
1003 * Allocates the memory needed for image->purgatory_info.sechdrs and
1004 * image->purgatory_info.purgatory_buf/kbuf->buffer. Caller is responsible
1005 * to free the memory after use.
1007 * Return: 0 on success, negative errno on error.
1009 int kexec_load_purgatory(struct kimage
*image
, struct kexec_buf
*kbuf
)
1011 struct purgatory_info
*pi
= &image
->purgatory_info
;
1014 if (kexec_purgatory_size
<= 0)
1017 pi
->ehdr
= (const Elf_Ehdr
*)kexec_purgatory
;
1019 ret
= kexec_purgatory_setup_kbuf(pi
, kbuf
);
1023 ret
= kexec_purgatory_setup_sechdrs(pi
, kbuf
);
1027 ret
= kexec_apply_relocations(image
);
1036 vfree(pi
->purgatory_buf
);
1037 pi
->purgatory_buf
= NULL
;
1042 * kexec_purgatory_find_symbol - find a symbol in the purgatory
1043 * @pi: Purgatory to search in.
1044 * @name: Name of the symbol.
1046 * Return: pointer to symbol in read-only symtab on success, NULL on error.
1048 static const Elf_Sym
*kexec_purgatory_find_symbol(struct purgatory_info
*pi
,
1051 const Elf_Shdr
*sechdrs
;
1052 const Elf_Ehdr
*ehdr
;
1053 const Elf_Sym
*syms
;
1061 sechdrs
= (void *)ehdr
+ ehdr
->e_shoff
;
1063 for (i
= 0; i
< ehdr
->e_shnum
; i
++) {
1064 if (sechdrs
[i
].sh_type
!= SHT_SYMTAB
)
1067 if (sechdrs
[i
].sh_link
>= ehdr
->e_shnum
)
1068 /* Invalid strtab section number */
1070 strtab
= (void *)ehdr
+ sechdrs
[sechdrs
[i
].sh_link
].sh_offset
;
1071 syms
= (void *)ehdr
+ sechdrs
[i
].sh_offset
;
1073 /* Go through symbols for a match */
1074 for (k
= 0; k
< sechdrs
[i
].sh_size
/sizeof(Elf_Sym
); k
++) {
1075 if (ELF_ST_BIND(syms
[k
].st_info
) != STB_GLOBAL
)
1078 if (strcmp(strtab
+ syms
[k
].st_name
, name
) != 0)
1081 if (syms
[k
].st_shndx
== SHN_UNDEF
||
1082 syms
[k
].st_shndx
>= ehdr
->e_shnum
) {
1083 pr_debug("Symbol: %s has bad section index %d.\n",
1084 name
, syms
[k
].st_shndx
);
1088 /* Found the symbol we are looking for */
1096 void *kexec_purgatory_get_symbol_addr(struct kimage
*image
, const char *name
)
1098 struct purgatory_info
*pi
= &image
->purgatory_info
;
1102 sym
= kexec_purgatory_find_symbol(pi
, name
);
1104 return ERR_PTR(-EINVAL
);
1106 sechdr
= &pi
->sechdrs
[sym
->st_shndx
];
1109 * Returns the address where symbol will finally be loaded after
1110 * kexec_load_segment()
1112 return (void *)(sechdr
->sh_addr
+ sym
->st_value
);
1116 * Get or set value of a symbol. If "get_value" is true, symbol value is
1117 * returned in buf otherwise symbol value is set based on value in buf.
1119 int kexec_purgatory_get_set_symbol(struct kimage
*image
, const char *name
,
1120 void *buf
, unsigned int size
, bool get_value
)
1122 struct purgatory_info
*pi
= &image
->purgatory_info
;
1127 sym
= kexec_purgatory_find_symbol(pi
, name
);
1131 if (sym
->st_size
!= size
) {
1132 pr_err("symbol %s size mismatch: expected %lu actual %u\n",
1133 name
, (unsigned long)sym
->st_size
, size
);
1137 sec
= pi
->sechdrs
+ sym
->st_shndx
;
1139 if (sec
->sh_type
== SHT_NOBITS
) {
1140 pr_err("symbol %s is in a bss section. Cannot %s\n", name
,
1141 get_value
? "get" : "set");
1145 sym_buf
= (char *)pi
->purgatory_buf
+ sec
->sh_offset
+ sym
->st_value
;
1148 memcpy((void *)buf
, sym_buf
, size
);
1150 memcpy((void *)sym_buf
, buf
, size
);
1154 #endif /* CONFIG_ARCH_HAS_KEXEC_PURGATORY */
1156 int crash_exclude_mem_range(struct crash_mem
*mem
,
1157 unsigned long long mstart
, unsigned long long mend
)
1160 unsigned long long start
, end
;
1161 struct crash_mem_range temp_range
= {0, 0};
1163 for (i
= 0; i
< mem
->nr_ranges
; i
++) {
1164 start
= mem
->ranges
[i
].start
;
1165 end
= mem
->ranges
[i
].end
;
1167 if (mstart
> end
|| mend
< start
)
1170 /* Truncate any area outside of range */
1176 /* Found completely overlapping range */
1177 if (mstart
== start
&& mend
== end
) {
1178 mem
->ranges
[i
].start
= 0;
1179 mem
->ranges
[i
].end
= 0;
1180 if (i
< mem
->nr_ranges
- 1) {
1181 /* Shift rest of the ranges to left */
1182 for (j
= i
; j
< mem
->nr_ranges
- 1; j
++) {
1183 mem
->ranges
[j
].start
=
1184 mem
->ranges
[j
+1].start
;
1185 mem
->ranges
[j
].end
=
1186 mem
->ranges
[j
+1].end
;
1193 if (mstart
> start
&& mend
< end
) {
1194 /* Split original range */
1195 mem
->ranges
[i
].end
= mstart
- 1;
1196 temp_range
.start
= mend
+ 1;
1197 temp_range
.end
= end
;
1198 } else if (mstart
!= start
)
1199 mem
->ranges
[i
].end
= mstart
- 1;
1201 mem
->ranges
[i
].start
= mend
+ 1;
1205 /* If a split happened, add the split to array */
1206 if (!temp_range
.end
)
1209 /* Split happened */
1210 if (i
== mem
->max_nr_ranges
- 1)
1213 /* Location where new range should go */
1215 if (j
< mem
->nr_ranges
) {
1216 /* Move over all ranges one slot towards the end */
1217 for (i
= mem
->nr_ranges
- 1; i
>= j
; i
--)
1218 mem
->ranges
[i
+ 1] = mem
->ranges
[i
];
1221 mem
->ranges
[j
].start
= temp_range
.start
;
1222 mem
->ranges
[j
].end
= temp_range
.end
;
1227 int crash_prepare_elf64_headers(struct crash_mem
*mem
, int kernel_map
,
1228 void **addr
, unsigned long *sz
)
1232 unsigned long nr_cpus
= num_possible_cpus(), nr_phdr
, elf_sz
;
1234 unsigned int cpu
, i
;
1235 unsigned long long notes_addr
;
1236 unsigned long mstart
, mend
;
1238 /* extra phdr for vmcoreinfo elf note */
1239 nr_phdr
= nr_cpus
+ 1;
1240 nr_phdr
+= mem
->nr_ranges
;
1243 * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
1244 * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64).
1245 * I think this is required by tools like gdb. So same physical
1246 * memory will be mapped in two elf headers. One will contain kernel
1247 * text virtual addresses and other will have __va(physical) addresses.
1251 elf_sz
= sizeof(Elf64_Ehdr
) + nr_phdr
* sizeof(Elf64_Phdr
);
1252 elf_sz
= ALIGN(elf_sz
, ELF_CORE_HEADER_ALIGN
);
1254 buf
= vzalloc(elf_sz
);
1258 ehdr
= (Elf64_Ehdr
*)buf
;
1259 phdr
= (Elf64_Phdr
*)(ehdr
+ 1);
1260 memcpy(ehdr
->e_ident
, ELFMAG
, SELFMAG
);
1261 ehdr
->e_ident
[EI_CLASS
] = ELFCLASS64
;
1262 ehdr
->e_ident
[EI_DATA
] = ELFDATA2LSB
;
1263 ehdr
->e_ident
[EI_VERSION
] = EV_CURRENT
;
1264 ehdr
->e_ident
[EI_OSABI
] = ELF_OSABI
;
1265 memset(ehdr
->e_ident
+ EI_PAD
, 0, EI_NIDENT
- EI_PAD
);
1266 ehdr
->e_type
= ET_CORE
;
1267 ehdr
->e_machine
= ELF_ARCH
;
1268 ehdr
->e_version
= EV_CURRENT
;
1269 ehdr
->e_phoff
= sizeof(Elf64_Ehdr
);
1270 ehdr
->e_ehsize
= sizeof(Elf64_Ehdr
);
1271 ehdr
->e_phentsize
= sizeof(Elf64_Phdr
);
1273 /* Prepare one phdr of type PT_NOTE for each present cpu */
1274 for_each_present_cpu(cpu
) {
1275 phdr
->p_type
= PT_NOTE
;
1276 notes_addr
= per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes
, cpu
));
1277 phdr
->p_offset
= phdr
->p_paddr
= notes_addr
;
1278 phdr
->p_filesz
= phdr
->p_memsz
= sizeof(note_buf_t
);
1283 /* Prepare one PT_NOTE header for vmcoreinfo */
1284 phdr
->p_type
= PT_NOTE
;
1285 phdr
->p_offset
= phdr
->p_paddr
= paddr_vmcoreinfo_note();
1286 phdr
->p_filesz
= phdr
->p_memsz
= VMCOREINFO_NOTE_SIZE
;
1290 /* Prepare PT_LOAD type program header for kernel text region */
1292 phdr
->p_type
= PT_LOAD
;
1293 phdr
->p_flags
= PF_R
|PF_W
|PF_X
;
1294 phdr
->p_vaddr
= (unsigned long) _text
;
1295 phdr
->p_filesz
= phdr
->p_memsz
= _end
- _text
;
1296 phdr
->p_offset
= phdr
->p_paddr
= __pa_symbol(_text
);
1301 /* Go through all the ranges in mem->ranges[] and prepare phdr */
1302 for (i
= 0; i
< mem
->nr_ranges
; i
++) {
1303 mstart
= mem
->ranges
[i
].start
;
1304 mend
= mem
->ranges
[i
].end
;
1306 phdr
->p_type
= PT_LOAD
;
1307 phdr
->p_flags
= PF_R
|PF_W
|PF_X
;
1308 phdr
->p_offset
= mstart
;
1310 phdr
->p_paddr
= mstart
;
1311 phdr
->p_vaddr
= (unsigned long) __va(mstart
);
1312 phdr
->p_filesz
= phdr
->p_memsz
= mend
- mstart
+ 1;
1316 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",
1317 phdr
, phdr
->p_vaddr
, phdr
->p_paddr
, phdr
->p_filesz
,
1318 ehdr
->e_phnum
, phdr
->p_offset
);