2 * kexec.c - kexec system call
3 * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com>
5 * This source code is licensed under the GNU General Public License,
6 * Version 2. See the file COPYING for more details.
9 #define pr_fmt(fmt) "kexec: " fmt
11 #include <linux/capability.h>
13 #include <linux/file.h>
14 #include <linux/slab.h>
16 #include <linux/kexec.h>
17 #include <linux/mutex.h>
18 #include <linux/list.h>
19 #include <linux/highmem.h>
20 #include <linux/syscalls.h>
21 #include <linux/reboot.h>
22 #include <linux/ioport.h>
23 #include <linux/hardirq.h>
24 #include <linux/elf.h>
25 #include <linux/elfcore.h>
26 #include <linux/utsname.h>
27 #include <linux/numa.h>
28 #include <linux/suspend.h>
29 #include <linux/device.h>
30 #include <linux/freezer.h>
32 #include <linux/cpu.h>
33 #include <linux/console.h>
34 #include <linux/vmalloc.h>
35 #include <linux/swap.h>
36 #include <linux/syscore_ops.h>
37 #include <linux/compiler.h>
38 #include <linux/hugetlb.h>
41 #include <asm/uaccess.h>
43 #include <asm/sections.h>
45 #include <crypto/hash.h>
46 #include <crypto/sha.h>
48 /* Per cpu memory for storing cpu states in case of system crash. */
49 note_buf_t __percpu *crash_notes;
51 /* vmcoreinfo stuff */
52 static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES];
53 u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
54 size_t vmcoreinfo_size;
55 size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data);
57 /* Flag to indicate we are going to kexec a new kernel */
58 bool kexec_in_progress = false;
61 * Declare these symbols weak so that if architecture provides a purgatory,
62 * these will be overridden.
64 char __weak kexec_purgatory[0];
65 size_t __weak kexec_purgatory_size = 0;
67 #ifdef CONFIG_KEXEC_FILE
68 static int kexec_calculate_store_digests(struct kimage *image);
71 /* Location of the reserved area for the crash kernel */
72 struct resource crashk_res = {
73 .name = "Crash kernel",
76 .flags = IORESOURCE_BUSY | IORESOURCE_MEM
78 struct resource crashk_low_res = {
79 .name = "Crash kernel",
82 .flags = IORESOURCE_BUSY | IORESOURCE_MEM
85 int kexec_should_crash(struct task_struct *p)
87 if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops)
93 * When kexec transitions to the new kernel there is a one-to-one
94 * mapping between physical and virtual addresses. On processors
95 * where you can disable the MMU this is trivial, and easy. For
96 * others it is still a simple predictable page table to setup.
98 * In that environment kexec copies the new kernel to its final
99 * resting place. This means I can only support memory whose
100 * physical address can fit in an unsigned long. In particular
101 * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled.
102 * If the assembly stub has more restrictive requirements
103 * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be
104 * defined more restrictively in <asm/kexec.h>.
106 * The code for the transition from the current kernel to the
107 * the new kernel is placed in the control_code_buffer, whose size
108 * is given by KEXEC_CONTROL_PAGE_SIZE. In the best case only a single
109 * page of memory is necessary, but some architectures require more.
110 * Because this memory must be identity mapped in the transition from
111 * virtual to physical addresses it must live in the range
112 * 0 - TASK_SIZE, as only the user space mappings are arbitrarily
115 * The assembly stub in the control code buffer is passed a linked list
116 * of descriptor pages detailing the source pages of the new kernel,
117 * and the destination addresses of those source pages. As this data
118 * structure is not used in the context of the current OS, it must
121 * The code has been made to work with highmem pages and will use a
122 * destination page in its final resting place (if it happens
123 * to allocate it). The end product of this is that most of the
124 * physical address space, and most of RAM can be used.
126 * Future directions include:
127 * - allocating a page table with the control code buffer identity
128 * mapped, to simplify machine_kexec and make kexec_on_panic more
133 * KIMAGE_NO_DEST is an impossible destination address..., for
134 * allocating pages whose destination address we do not care about.
136 #define KIMAGE_NO_DEST (-1UL)
138 static int kimage_is_destination_range(struct kimage *image,
139 unsigned long start, unsigned long end);
140 static struct page *kimage_alloc_page(struct kimage *image,
144 static int copy_user_segment_list(struct kimage *image,
145 unsigned long nr_segments,
146 struct kexec_segment __user *segments)
149 size_t segment_bytes;
151 /* Read in the segments */
152 image->nr_segments = nr_segments;
153 segment_bytes = nr_segments * sizeof(*segments);
154 ret = copy_from_user(image->segment, segments, segment_bytes);
161 static int sanity_check_segment_list(struct kimage *image)
164 unsigned long nr_segments = image->nr_segments;
167 * Verify we have good destination addresses. The caller is
168 * responsible for making certain we don't attempt to load
169 * the new image into invalid or reserved areas of RAM. This
170 * just verifies it is an address we can use.
172 * Since the kernel does everything in page size chunks ensure
173 * the destination addresses are page aligned. Too many
174 * special cases crop of when we don't do this. The most
175 * insidious is getting overlapping destination addresses
176 * simply because addresses are changed to page size
179 result = -EADDRNOTAVAIL;
180 for (i = 0; i < nr_segments; i++) {
181 unsigned long mstart, mend;
183 mstart = image->segment[i].mem;
184 mend = mstart + image->segment[i].memsz;
185 if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK))
187 if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT)
191 /* Verify our destination addresses do not overlap.
192 * If we alloed overlapping destination addresses
193 * through very weird things can happen with no
194 * easy explanation as one segment stops on another.
197 for (i = 0; i < nr_segments; i++) {
198 unsigned long mstart, mend;
201 mstart = image->segment[i].mem;
202 mend = mstart + image->segment[i].memsz;
203 for (j = 0; j < i; j++) {
204 unsigned long pstart, pend;
205 pstart = image->segment[j].mem;
206 pend = pstart + image->segment[j].memsz;
207 /* Do the segments overlap ? */
208 if ((mend > pstart) && (mstart < pend))
213 /* Ensure our buffer sizes are strictly less than
214 * our memory sizes. This should always be the case,
215 * and it is easier to check up front than to be surprised
219 for (i = 0; i < nr_segments; i++) {
220 if (image->segment[i].bufsz > image->segment[i].memsz)
225 * Verify we have good destination addresses. Normally
226 * the caller is responsible for making certain we don't
227 * attempt to load the new image into invalid or reserved
228 * areas of RAM. But crash kernels are preloaded into a
229 * reserved area of ram. We must ensure the addresses
230 * are in the reserved area otherwise preloading the
231 * kernel could corrupt things.
234 if (image->type == KEXEC_TYPE_CRASH) {
235 result = -EADDRNOTAVAIL;
236 for (i = 0; i < nr_segments; i++) {
237 unsigned long mstart, mend;
239 mstart = image->segment[i].mem;
240 mend = mstart + image->segment[i].memsz - 1;
241 /* Ensure we are within the crash kernel limits */
242 if ((mstart < crashk_res.start) ||
243 (mend > crashk_res.end))
251 static struct kimage *do_kimage_alloc_init(void)
253 struct kimage *image;
255 /* Allocate a controlling structure */
256 image = kzalloc(sizeof(*image), GFP_KERNEL);
261 image->entry = &image->head;
262 image->last_entry = &image->head;
263 image->control_page = ~0; /* By default this does not apply */
264 image->type = KEXEC_TYPE_DEFAULT;
266 /* Initialize the list of control pages */
267 INIT_LIST_HEAD(&image->control_pages);
269 /* Initialize the list of destination pages */
270 INIT_LIST_HEAD(&image->dest_pages);
272 /* Initialize the list of unusable pages */
273 INIT_LIST_HEAD(&image->unusable_pages);
278 static void kimage_free_page_list(struct list_head *list);
280 static int kimage_alloc_init(struct kimage **rimage, unsigned long entry,
281 unsigned long nr_segments,
282 struct kexec_segment __user *segments,
286 struct kimage *image;
287 bool kexec_on_panic = flags & KEXEC_ON_CRASH;
289 if (kexec_on_panic) {
290 /* Verify we have a valid entry point */
291 if ((entry < crashk_res.start) || (entry > crashk_res.end))
292 return -EADDRNOTAVAIL;
295 /* Allocate and initialize a controlling structure */
296 image = do_kimage_alloc_init();
300 image->start = entry;
302 ret = copy_user_segment_list(image, nr_segments, segments);
306 ret = sanity_check_segment_list(image);
310 /* Enable the special crash kernel control page allocation policy. */
311 if (kexec_on_panic) {
312 image->control_page = crashk_res.start;
313 image->type = KEXEC_TYPE_CRASH;
317 * Find a location for the control code buffer, and add it
318 * the vector of segments so that it's pages will also be
319 * counted as destination pages.
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");
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);
346 #ifdef CONFIG_KEXEC_FILE
347 static int copy_file_from_fd(int fd, void **buf, unsigned long *buf_len)
349 struct fd f = fdget(fd);
358 ret = vfs_getattr(&f.file->f_path, &stat);
362 if (stat.size > INT_MAX) {
367 /* Don't hand 0 to vmalloc, it whines. */
368 if (stat.size == 0) {
373 *buf = vmalloc(stat.size);
380 while (pos < stat.size) {
381 bytes = kernel_read(f.file, pos, (char *)(*buf) + pos,
394 if (pos != stat.size) {
406 /* Architectures can provide this probe function */
407 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
408 unsigned long buf_len)
413 void * __weak arch_kexec_kernel_image_load(struct kimage *image)
415 return ERR_PTR(-ENOEXEC);
418 void __weak arch_kimage_file_post_load_cleanup(struct kimage *image)
422 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
423 unsigned long buf_len)
425 return -EKEYREJECTED;
428 /* Apply relocations of type RELA */
430 arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
433 pr_err("RELA relocation unsupported.\n");
437 /* Apply relocations of type REL */
439 arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
442 pr_err("REL relocation unsupported.\n");
447 * Free up memory used by kernel, initrd, and command line. This is temporary
448 * memory allocation which is not needed any more after these buffers have
449 * been loaded into separate segments and have been copied elsewhere.
451 static void kimage_file_post_load_cleanup(struct kimage *image)
453 struct purgatory_info *pi = &image->purgatory_info;
455 vfree(image->kernel_buf);
456 image->kernel_buf = NULL;
458 vfree(image->initrd_buf);
459 image->initrd_buf = NULL;
461 kfree(image->cmdline_buf);
462 image->cmdline_buf = NULL;
464 vfree(pi->purgatory_buf);
465 pi->purgatory_buf = NULL;
470 /* See if architecture has anything to cleanup post load */
471 arch_kimage_file_post_load_cleanup(image);
474 * Above call should have called into bootloader to free up
475 * any data stored in kimage->image_loader_data. It should
476 * be ok now to free it up.
478 kfree(image->image_loader_data);
479 image->image_loader_data = NULL;
483 * In file mode list of segments is prepared by kernel. Copy relevant
484 * data from user space, do error checking, prepare segment list
487 kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
488 const char __user *cmdline_ptr,
489 unsigned long cmdline_len, unsigned flags)
494 ret = copy_file_from_fd(kernel_fd, &image->kernel_buf,
495 &image->kernel_buf_len);
499 /* Call arch image probe handlers */
500 ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
501 image->kernel_buf_len);
506 #ifdef CONFIG_KEXEC_VERIFY_SIG
507 ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf,
508 image->kernel_buf_len);
510 pr_debug("kernel signature verification failed.\n");
513 pr_debug("kernel signature verification successful.\n");
515 /* It is possible that there no initramfs is being loaded */
516 if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
517 ret = copy_file_from_fd(initrd_fd, &image->initrd_buf,
518 &image->initrd_buf_len);
524 image->cmdline_buf = kzalloc(cmdline_len, GFP_KERNEL);
525 if (!image->cmdline_buf) {
530 ret = copy_from_user(image->cmdline_buf, cmdline_ptr,
537 image->cmdline_buf_len = cmdline_len;
539 /* command line should be a string with last byte null */
540 if (image->cmdline_buf[cmdline_len - 1] != '\0') {
546 /* Call arch image load handlers */
547 ldata = arch_kexec_kernel_image_load(image);
550 ret = PTR_ERR(ldata);
554 image->image_loader_data = ldata;
556 /* In case of error, free up all allocated memory in this function */
558 kimage_file_post_load_cleanup(image);
563 kimage_file_alloc_init(struct kimage **rimage, int kernel_fd,
564 int initrd_fd, const char __user *cmdline_ptr,
565 unsigned long cmdline_len, unsigned long flags)
568 struct kimage *image;
569 bool kexec_on_panic = flags & KEXEC_FILE_ON_CRASH;
571 image = do_kimage_alloc_init();
575 image->file_mode = 1;
577 if (kexec_on_panic) {
578 /* Enable special crash kernel control page alloc policy. */
579 image->control_page = crashk_res.start;
580 image->type = KEXEC_TYPE_CRASH;
583 ret = kimage_file_prepare_segments(image, kernel_fd, initrd_fd,
584 cmdline_ptr, cmdline_len, flags);
588 ret = sanity_check_segment_list(image);
590 goto out_free_post_load_bufs;
593 image->control_code_page = kimage_alloc_control_pages(image,
594 get_order(KEXEC_CONTROL_PAGE_SIZE));
595 if (!image->control_code_page) {
596 pr_err("Could not allocate control_code_buffer\n");
597 goto out_free_post_load_bufs;
600 if (!kexec_on_panic) {
601 image->swap_page = kimage_alloc_control_pages(image, 0);
602 if (!image->swap_page) {
603 pr_err("Could not allocate swap buffer\n");
604 goto out_free_control_pages;
610 out_free_control_pages:
611 kimage_free_page_list(&image->control_pages);
612 out_free_post_load_bufs:
613 kimage_file_post_load_cleanup(image);
618 #else /* CONFIG_KEXEC_FILE */
619 static inline void kimage_file_post_load_cleanup(struct kimage *image) { }
620 #endif /* CONFIG_KEXEC_FILE */
622 static int kimage_is_destination_range(struct kimage *image,
628 for (i = 0; i < image->nr_segments; i++) {
629 unsigned long mstart, mend;
631 mstart = image->segment[i].mem;
632 mend = mstart + image->segment[i].memsz;
633 if ((end > mstart) && (start < mend))
640 static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order)
644 pages = alloc_pages(gfp_mask, order);
646 unsigned int count, i;
647 pages->mapping = NULL;
648 set_page_private(pages, order);
650 for (i = 0; i < count; i++)
651 SetPageReserved(pages + i);
657 static void kimage_free_pages(struct page *page)
659 unsigned int order, count, i;
661 order = page_private(page);
663 for (i = 0; i < count; i++)
664 ClearPageReserved(page + i);
665 __free_pages(page, order);
668 static void kimage_free_page_list(struct list_head *list)
670 struct list_head *pos, *next;
672 list_for_each_safe(pos, next, list) {
675 page = list_entry(pos, struct page, lru);
676 list_del(&page->lru);
677 kimage_free_pages(page);
681 static struct page *kimage_alloc_normal_control_pages(struct kimage *image,
684 /* Control pages are special, they are the intermediaries
685 * that are needed while we copy the rest of the pages
686 * to their final resting place. As such they must
687 * not conflict with either the destination addresses
688 * or memory the kernel is already using.
690 * The only case where we really need more than one of
691 * these are for architectures where we cannot disable
692 * the MMU and must instead generate an identity mapped
693 * page table for all of the memory.
695 * At worst this runs in O(N) of the image size.
697 struct list_head extra_pages;
702 INIT_LIST_HEAD(&extra_pages);
704 /* Loop while I can allocate a page and the page allocated
705 * is a destination page.
708 unsigned long pfn, epfn, addr, eaddr;
710 pages = kimage_alloc_pages(KEXEC_CONTROL_MEMORY_GFP, order);
713 pfn = page_to_pfn(pages);
715 addr = pfn << PAGE_SHIFT;
716 eaddr = epfn << PAGE_SHIFT;
717 if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) ||
718 kimage_is_destination_range(image, addr, eaddr)) {
719 list_add(&pages->lru, &extra_pages);
725 /* Remember the allocated page... */
726 list_add(&pages->lru, &image->control_pages);
728 /* Because the page is already in it's destination
729 * location we will never allocate another page at
730 * that address. Therefore kimage_alloc_pages
731 * will not return it (again) and we don't need
732 * to give it an entry in image->segment[].
735 /* Deal with the destination pages I have inadvertently allocated.
737 * Ideally I would convert multi-page allocations into single
738 * page allocations, and add everything to image->dest_pages.
740 * For now it is simpler to just free the pages.
742 kimage_free_page_list(&extra_pages);
747 static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
750 /* Control pages are special, they are the intermediaries
751 * that are needed while we copy the rest of the pages
752 * to their final resting place. As such they must
753 * not conflict with either the destination addresses
754 * or memory the kernel is already using.
756 * Control pages are also the only pags we must allocate
757 * when loading a crash kernel. All of the other pages
758 * are specified by the segments and we just memcpy
759 * into them directly.
761 * The only case where we really need more than one of
762 * these are for architectures where we cannot disable
763 * the MMU and must instead generate an identity mapped
764 * page table for all of the memory.
766 * Given the low demand this implements a very simple
767 * allocator that finds the first hole of the appropriate
768 * size in the reserved memory region, and allocates all
769 * of the memory up to and including the hole.
771 unsigned long hole_start, hole_end, size;
775 size = (1 << order) << PAGE_SHIFT;
776 hole_start = (image->control_page + (size - 1)) & ~(size - 1);
777 hole_end = hole_start + size - 1;
778 while (hole_end <= crashk_res.end) {
781 if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT)
783 /* See if I overlap any of the segments */
784 for (i = 0; i < image->nr_segments; i++) {
785 unsigned long mstart, mend;
787 mstart = image->segment[i].mem;
788 mend = mstart + image->segment[i].memsz - 1;
789 if ((hole_end >= mstart) && (hole_start <= mend)) {
790 /* Advance the hole to the end of the segment */
791 hole_start = (mend + (size - 1)) & ~(size - 1);
792 hole_end = hole_start + size - 1;
796 /* If I don't overlap any segments I have found my hole! */
797 if (i == image->nr_segments) {
798 pages = pfn_to_page(hole_start >> PAGE_SHIFT);
803 image->control_page = hole_end;
809 struct page *kimage_alloc_control_pages(struct kimage *image,
812 struct page *pages = NULL;
814 switch (image->type) {
815 case KEXEC_TYPE_DEFAULT:
816 pages = kimage_alloc_normal_control_pages(image, order);
818 case KEXEC_TYPE_CRASH:
819 pages = kimage_alloc_crash_control_pages(image, order);
826 static int kimage_add_entry(struct kimage *image, kimage_entry_t entry)
828 if (*image->entry != 0)
831 if (image->entry == image->last_entry) {
832 kimage_entry_t *ind_page;
835 page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST);
839 ind_page = page_address(page);
840 *image->entry = virt_to_phys(ind_page) | IND_INDIRECTION;
841 image->entry = ind_page;
842 image->last_entry = ind_page +
843 ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1);
845 *image->entry = entry;
852 static int kimage_set_destination(struct kimage *image,
853 unsigned long destination)
857 destination &= PAGE_MASK;
858 result = kimage_add_entry(image, destination | IND_DESTINATION);
864 static int kimage_add_page(struct kimage *image, unsigned long page)
869 result = kimage_add_entry(image, page | IND_SOURCE);
875 static void kimage_free_extra_pages(struct kimage *image)
877 /* Walk through and free any extra destination pages I may have */
878 kimage_free_page_list(&image->dest_pages);
880 /* Walk through and free any unusable pages I have cached */
881 kimage_free_page_list(&image->unusable_pages);
884 static void kimage_terminate(struct kimage *image)
886 if (*image->entry != 0)
889 *image->entry = IND_DONE;
892 #define for_each_kimage_entry(image, ptr, entry) \
893 for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \
894 ptr = (entry & IND_INDIRECTION) ? \
895 phys_to_virt((entry & PAGE_MASK)) : ptr + 1)
897 static void kimage_free_entry(kimage_entry_t entry)
901 page = pfn_to_page(entry >> PAGE_SHIFT);
902 kimage_free_pages(page);
905 static void kimage_free(struct kimage *image)
907 kimage_entry_t *ptr, entry;
908 kimage_entry_t ind = 0;
913 kimage_free_extra_pages(image);
914 for_each_kimage_entry(image, ptr, entry) {
915 if (entry & IND_INDIRECTION) {
916 /* Free the previous indirection page */
917 if (ind & IND_INDIRECTION)
918 kimage_free_entry(ind);
919 /* Save this indirection page until we are
923 } else if (entry & IND_SOURCE)
924 kimage_free_entry(entry);
926 /* Free the final indirection page */
927 if (ind & IND_INDIRECTION)
928 kimage_free_entry(ind);
930 /* Handle any machine specific cleanup */
931 machine_kexec_cleanup(image);
933 /* Free the kexec control pages... */
934 kimage_free_page_list(&image->control_pages);
937 * Free up any temporary buffers allocated. This might hit if
938 * error occurred much later after buffer allocation.
940 if (image->file_mode)
941 kimage_file_post_load_cleanup(image);
946 static kimage_entry_t *kimage_dst_used(struct kimage *image,
949 kimage_entry_t *ptr, entry;
950 unsigned long destination = 0;
952 for_each_kimage_entry(image, ptr, entry) {
953 if (entry & IND_DESTINATION)
954 destination = entry & PAGE_MASK;
955 else if (entry & IND_SOURCE) {
956 if (page == destination)
958 destination += PAGE_SIZE;
965 static struct page *kimage_alloc_page(struct kimage *image,
967 unsigned long destination)
970 * Here we implement safeguards to ensure that a source page
971 * is not copied to its destination page before the data on
972 * the destination page is no longer useful.
974 * To do this we maintain the invariant that a source page is
975 * either its own destination page, or it is not a
976 * destination page at all.
978 * That is slightly stronger than required, but the proof
979 * that no problems will not occur is trivial, and the
980 * implementation is simply to verify.
982 * When allocating all pages normally this algorithm will run
983 * in O(N) time, but in the worst case it will run in O(N^2)
984 * time. If the runtime is a problem the data structures can
991 * Walk through the list of destination pages, and see if I
994 list_for_each_entry(page, &image->dest_pages, lru) {
995 addr = page_to_pfn(page) << PAGE_SHIFT;
996 if (addr == destination) {
997 list_del(&page->lru);
1003 kimage_entry_t *old;
1005 /* Allocate a page, if we run out of memory give up */
1006 page = kimage_alloc_pages(gfp_mask, 0);
1009 /* If the page cannot be used file it away */
1010 if (page_to_pfn(page) >
1011 (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
1012 list_add(&page->lru, &image->unusable_pages);
1015 addr = page_to_pfn(page) << PAGE_SHIFT;
1017 /* If it is the destination page we want use it */
1018 if (addr == destination)
1021 /* If the page is not a destination page use it */
1022 if (!kimage_is_destination_range(image, addr,
1027 * I know that the page is someones destination page.
1028 * See if there is already a source page for this
1029 * destination page. And if so swap the source pages.
1031 old = kimage_dst_used(image, addr);
1034 unsigned long old_addr;
1035 struct page *old_page;
1037 old_addr = *old & PAGE_MASK;
1038 old_page = pfn_to_page(old_addr >> PAGE_SHIFT);
1039 copy_highpage(page, old_page);
1040 *old = addr | (*old & ~PAGE_MASK);
1042 /* The old page I have found cannot be a
1043 * destination page, so return it if it's
1044 * gfp_flags honor the ones passed in.
1046 if (!(gfp_mask & __GFP_HIGHMEM) &&
1047 PageHighMem(old_page)) {
1048 kimage_free_pages(old_page);
1055 /* Place the page on the destination list I
1056 * will use it later.
1058 list_add(&page->lru, &image->dest_pages);
1065 static int kimage_load_normal_segment(struct kimage *image,
1066 struct kexec_segment *segment)
1068 unsigned long maddr;
1069 size_t ubytes, mbytes;
1071 unsigned char __user *buf = NULL;
1072 unsigned char *kbuf = NULL;
1075 if (image->file_mode)
1076 kbuf = segment->kbuf;
1079 ubytes = segment->bufsz;
1080 mbytes = segment->memsz;
1081 maddr = segment->mem;
1083 result = kimage_set_destination(image, maddr);
1090 size_t uchunk, mchunk;
1092 page = kimage_alloc_page(image, GFP_HIGHUSER, maddr);
1097 result = kimage_add_page(image, page_to_pfn(page)
1103 /* Start with a clear page */
1105 ptr += maddr & ~PAGE_MASK;
1106 mchunk = min_t(size_t, mbytes,
1107 PAGE_SIZE - (maddr & ~PAGE_MASK));
1108 uchunk = min(ubytes, mchunk);
1110 /* For file based kexec, source pages are in kernel memory */
1111 if (image->file_mode)
1112 memcpy(ptr, kbuf, uchunk);
1114 result = copy_from_user(ptr, buf, uchunk);
1122 if (image->file_mode)
1132 static int kimage_load_crash_segment(struct kimage *image,
1133 struct kexec_segment *segment)
1135 /* For crash dumps kernels we simply copy the data from
1136 * user space to it's destination.
1137 * We do things a page at a time for the sake of kmap.
1139 unsigned long maddr;
1140 size_t ubytes, mbytes;
1142 unsigned char __user *buf = NULL;
1143 unsigned char *kbuf = NULL;
1146 if (image->file_mode)
1147 kbuf = segment->kbuf;
1150 ubytes = segment->bufsz;
1151 mbytes = segment->memsz;
1152 maddr = segment->mem;
1156 size_t uchunk, mchunk;
1158 page = pfn_to_page(maddr >> PAGE_SHIFT);
1164 ptr += maddr & ~PAGE_MASK;
1165 mchunk = min_t(size_t, mbytes,
1166 PAGE_SIZE - (maddr & ~PAGE_MASK));
1167 uchunk = min(ubytes, mchunk);
1168 if (mchunk > uchunk) {
1169 /* Zero the trailing part of the page */
1170 memset(ptr + uchunk, 0, mchunk - uchunk);
1173 /* For file based kexec, source pages are in kernel memory */
1174 if (image->file_mode)
1175 memcpy(ptr, kbuf, uchunk);
1177 result = copy_from_user(ptr, buf, uchunk);
1178 kexec_flush_icache_page(page);
1186 if (image->file_mode)
1196 static int kimage_load_segment(struct kimage *image,
1197 struct kexec_segment *segment)
1199 int result = -ENOMEM;
1201 switch (image->type) {
1202 case KEXEC_TYPE_DEFAULT:
1203 result = kimage_load_normal_segment(image, segment);
1205 case KEXEC_TYPE_CRASH:
1206 result = kimage_load_crash_segment(image, segment);
1214 * Exec Kernel system call: for obvious reasons only root may call it.
1216 * This call breaks up into three pieces.
1217 * - A generic part which loads the new kernel from the current
1218 * address space, and very carefully places the data in the
1221 * - A generic part that interacts with the kernel and tells all of
1222 * the devices to shut down. Preventing on-going dmas, and placing
1223 * the devices in a consistent state so a later kernel can
1224 * reinitialize them.
1226 * - A machine specific part that includes the syscall number
1227 * and then copies the image to it's final destination. And
1228 * jumps into the image at entry.
1230 * kexec does not sync, or unmount filesystems so if you need
1231 * that to happen you need to do that yourself.
1233 struct kimage *kexec_image;
1234 struct kimage *kexec_crash_image;
1235 int kexec_load_disabled;
1237 static DEFINE_MUTEX(kexec_mutex);
1239 SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
1240 struct kexec_segment __user *, segments, unsigned long, flags)
1242 struct kimage **dest_image, *image;
1245 /* We only trust the superuser with rebooting the system. */
1246 if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
1250 * Verify we have a legal set of flags
1251 * This leaves us room for future extensions.
1253 if ((flags & KEXEC_FLAGS) != (flags & ~KEXEC_ARCH_MASK))
1256 /* Verify we are on the appropriate architecture */
1257 if (((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH) &&
1258 ((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT))
1261 /* Put an artificial cap on the number
1262 * of segments passed to kexec_load.
1264 if (nr_segments > KEXEC_SEGMENT_MAX)
1270 /* Because we write directly to the reserved memory
1271 * region when loading crash kernels we need a mutex here to
1272 * prevent multiple crash kernels from attempting to load
1273 * simultaneously, and to prevent a crash kernel from loading
1274 * over the top of a in use crash kernel.
1276 * KISS: always take the mutex.
1278 if (!mutex_trylock(&kexec_mutex))
1281 dest_image = &kexec_image;
1282 if (flags & KEXEC_ON_CRASH)
1283 dest_image = &kexec_crash_image;
1284 if (nr_segments > 0) {
1287 if (flags & KEXEC_ON_CRASH) {
1289 * Loading another kernel to switch to if this one
1290 * crashes. Free any current crash dump kernel before
1294 kimage_free(xchg(&kexec_crash_image, NULL));
1295 result = kimage_alloc_init(&image, entry, nr_segments,
1297 crash_map_reserved_pages();
1299 /* Loading another kernel to reboot into. */
1301 result = kimage_alloc_init(&image, entry, nr_segments,
1307 if (flags & KEXEC_PRESERVE_CONTEXT)
1308 image->preserve_context = 1;
1309 result = machine_kexec_prepare(image);
1313 for (i = 0; i < nr_segments; i++) {
1314 result = kimage_load_segment(image, &image->segment[i]);
1318 kimage_terminate(image);
1319 if (flags & KEXEC_ON_CRASH)
1320 crash_unmap_reserved_pages();
1322 /* Install the new kernel, and Uninstall the old */
1323 image = xchg(dest_image, image);
1326 mutex_unlock(&kexec_mutex);
1333 * Add and remove page tables for crashkernel memory
1335 * Provide an empty default implementation here -- architecture
1336 * code may override this
1338 void __weak crash_map_reserved_pages(void)
1341 void __weak crash_unmap_reserved_pages(void)
1344 #ifdef CONFIG_COMPAT
1345 COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry,
1346 compat_ulong_t, nr_segments,
1347 struct compat_kexec_segment __user *, segments,
1348 compat_ulong_t, flags)
1350 struct compat_kexec_segment in;
1351 struct kexec_segment out, __user *ksegments;
1352 unsigned long i, result;
1354 /* Don't allow clients that don't understand the native
1355 * architecture to do anything.
1357 if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT)
1360 if (nr_segments > KEXEC_SEGMENT_MAX)
1363 ksegments = compat_alloc_user_space(nr_segments * sizeof(out));
1364 for (i = 0; i < nr_segments; i++) {
1365 result = copy_from_user(&in, &segments[i], sizeof(in));
1369 out.buf = compat_ptr(in.buf);
1370 out.bufsz = in.bufsz;
1372 out.memsz = in.memsz;
1374 result = copy_to_user(&ksegments[i], &out, sizeof(out));
1379 return sys_kexec_load(entry, nr_segments, ksegments, flags);
1383 #ifdef CONFIG_KEXEC_FILE
1384 SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
1385 unsigned long, cmdline_len, const char __user *, cmdline_ptr,
1386 unsigned long, flags)
1389 struct kimage **dest_image, *image;
1391 /* We only trust the superuser with rebooting the system. */
1392 if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
1395 /* Make sure we have a legal set of flags */
1396 if (flags != (flags & KEXEC_FILE_FLAGS))
1401 if (!mutex_trylock(&kexec_mutex))
1404 dest_image = &kexec_image;
1405 if (flags & KEXEC_FILE_ON_CRASH)
1406 dest_image = &kexec_crash_image;
1408 if (flags & KEXEC_FILE_UNLOAD)
1412 * In case of crash, new kernel gets loaded in reserved region. It is
1413 * same memory where old crash kernel might be loaded. Free any
1414 * current crash dump kernel before we corrupt it.
1416 if (flags & KEXEC_FILE_ON_CRASH)
1417 kimage_free(xchg(&kexec_crash_image, NULL));
1419 ret = kimage_file_alloc_init(&image, kernel_fd, initrd_fd, cmdline_ptr,
1420 cmdline_len, flags);
1424 ret = machine_kexec_prepare(image);
1428 ret = kexec_calculate_store_digests(image);
1432 for (i = 0; i < image->nr_segments; i++) {
1433 struct kexec_segment *ksegment;
1435 ksegment = &image->segment[i];
1436 pr_debug("Loading segment %d: buf=0x%p bufsz=0x%zx mem=0x%lx memsz=0x%zx\n",
1437 i, ksegment->buf, ksegment->bufsz, ksegment->mem,
1440 ret = kimage_load_segment(image, &image->segment[i]);
1445 kimage_terminate(image);
1448 * Free up any temporary buffers allocated which are not needed
1449 * after image has been loaded
1451 kimage_file_post_load_cleanup(image);
1453 image = xchg(dest_image, image);
1455 mutex_unlock(&kexec_mutex);
1460 #endif /* CONFIG_KEXEC_FILE */
1462 void crash_kexec(struct pt_regs *regs)
1464 /* Take the kexec_mutex here to prevent sys_kexec_load
1465 * running on one cpu from replacing the crash kernel
1466 * we are using after a panic on a different cpu.
1468 * If the crash kernel was not located in a fixed area
1469 * of memory the xchg(&kexec_crash_image) would be
1470 * sufficient. But since I reuse the memory...
1472 if (mutex_trylock(&kexec_mutex)) {
1473 if (kexec_crash_image) {
1474 struct pt_regs fixed_regs;
1476 crash_setup_regs(&fixed_regs, regs);
1477 crash_save_vmcoreinfo();
1478 machine_crash_shutdown(&fixed_regs);
1479 machine_kexec(kexec_crash_image);
1481 mutex_unlock(&kexec_mutex);
1485 size_t crash_get_memory_size(void)
1488 mutex_lock(&kexec_mutex);
1489 if (crashk_res.end != crashk_res.start)
1490 size = resource_size(&crashk_res);
1491 mutex_unlock(&kexec_mutex);
1495 void __weak crash_free_reserved_phys_range(unsigned long begin,
1500 for (addr = begin; addr < end; addr += PAGE_SIZE)
1501 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
1504 int crash_shrink_memory(unsigned long new_size)
1507 unsigned long start, end;
1508 unsigned long old_size;
1509 struct resource *ram_res;
1511 mutex_lock(&kexec_mutex);
1513 if (kexec_crash_image) {
1517 start = crashk_res.start;
1518 end = crashk_res.end;
1519 old_size = (end == 0) ? 0 : end - start + 1;
1520 if (new_size >= old_size) {
1521 ret = (new_size == old_size) ? 0 : -EINVAL;
1525 ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL);
1531 start = roundup(start, KEXEC_CRASH_MEM_ALIGN);
1532 end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN);
1534 crash_map_reserved_pages();
1535 crash_free_reserved_phys_range(end, crashk_res.end);
1537 if ((start == end) && (crashk_res.parent != NULL))
1538 release_resource(&crashk_res);
1540 ram_res->start = end;
1541 ram_res->end = crashk_res.end;
1542 ram_res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
1543 ram_res->name = "System RAM";
1545 crashk_res.end = end - 1;
1547 insert_resource(&iomem_resource, ram_res);
1548 crash_unmap_reserved_pages();
1551 mutex_unlock(&kexec_mutex);
1555 static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data,
1558 struct elf_note note;
1560 note.n_namesz = strlen(name) + 1;
1561 note.n_descsz = data_len;
1563 memcpy(buf, ¬e, sizeof(note));
1564 buf += (sizeof(note) + 3)/4;
1565 memcpy(buf, name, note.n_namesz);
1566 buf += (note.n_namesz + 3)/4;
1567 memcpy(buf, data, note.n_descsz);
1568 buf += (note.n_descsz + 3)/4;
1573 static void final_note(u32 *buf)
1575 struct elf_note note;
1580 memcpy(buf, ¬e, sizeof(note));
1583 void crash_save_cpu(struct pt_regs *regs, int cpu)
1585 struct elf_prstatus prstatus;
1588 if ((cpu < 0) || (cpu >= nr_cpu_ids))
1591 /* Using ELF notes here is opportunistic.
1592 * I need a well defined structure format
1593 * for the data I pass, and I need tags
1594 * on the data to indicate what information I have
1595 * squirrelled away. ELF notes happen to provide
1596 * all of that, so there is no need to invent something new.
1598 buf = (u32 *)per_cpu_ptr(crash_notes, cpu);
1601 memset(&prstatus, 0, sizeof(prstatus));
1602 prstatus.pr_pid = current->pid;
1603 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
1604 buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
1605 &prstatus, sizeof(prstatus));
1609 static int __init crash_notes_memory_init(void)
1611 /* Allocate memory for saving cpu registers. */
1612 crash_notes = alloc_percpu(note_buf_t);
1614 pr_warn("Kexec: Memory allocation for saving cpu register states failed\n");
1619 subsys_initcall(crash_notes_memory_init);
1623 * parsing the "crashkernel" commandline
1625 * this code is intended to be called from architecture specific code
1630 * This function parses command lines in the format
1632 * crashkernel=ramsize-range:size[,...][@offset]
1634 * The function returns 0 on success and -EINVAL on failure.
1636 static int __init parse_crashkernel_mem(char *cmdline,
1637 unsigned long long system_ram,
1638 unsigned long long *crash_size,
1639 unsigned long long *crash_base)
1641 char *cur = cmdline, *tmp;
1643 /* for each entry of the comma-separated list */
1645 unsigned long long start, end = ULLONG_MAX, size;
1647 /* get the start of the range */
1648 start = memparse(cur, &tmp);
1650 pr_warn("crashkernel: Memory value expected\n");
1655 pr_warn("crashkernel: '-' expected\n");
1660 /* if no ':' is here, than we read the end */
1662 end = memparse(cur, &tmp);
1664 pr_warn("crashkernel: Memory value expected\n");
1669 pr_warn("crashkernel: end <= start\n");
1675 pr_warn("crashkernel: ':' expected\n");
1680 size = memparse(cur, &tmp);
1682 pr_warn("Memory value expected\n");
1686 if (size >= system_ram) {
1687 pr_warn("crashkernel: invalid size\n");
1692 if (system_ram >= start && system_ram < end) {
1696 } while (*cur++ == ',');
1698 if (*crash_size > 0) {
1699 while (*cur && *cur != ' ' && *cur != '@')
1703 *crash_base = memparse(cur, &tmp);
1705 pr_warn("Memory value expected after '@'\n");
1715 * That function parses "simple" (old) crashkernel command lines like
1717 * crashkernel=size[@offset]
1719 * It returns 0 on success and -EINVAL on failure.
1721 static int __init parse_crashkernel_simple(char *cmdline,
1722 unsigned long long *crash_size,
1723 unsigned long long *crash_base)
1725 char *cur = cmdline;
1727 *crash_size = memparse(cmdline, &cur);
1728 if (cmdline == cur) {
1729 pr_warn("crashkernel: memory value expected\n");
1734 *crash_base = memparse(cur+1, &cur);
1735 else if (*cur != ' ' && *cur != '\0') {
1736 pr_warn("crashkernel: unrecognized char\n");
1743 #define SUFFIX_HIGH 0
1744 #define SUFFIX_LOW 1
1745 #define SUFFIX_NULL 2
1746 static __initdata char *suffix_tbl[] = {
1747 [SUFFIX_HIGH] = ",high",
1748 [SUFFIX_LOW] = ",low",
1749 [SUFFIX_NULL] = NULL,
1753 * That function parses "suffix" crashkernel command lines like
1755 * crashkernel=size,[high|low]
1757 * It returns 0 on success and -EINVAL on failure.
1759 static int __init parse_crashkernel_suffix(char *cmdline,
1760 unsigned long long *crash_size,
1763 char *cur = cmdline;
1765 *crash_size = memparse(cmdline, &cur);
1766 if (cmdline == cur) {
1767 pr_warn("crashkernel: memory value expected\n");
1771 /* check with suffix */
1772 if (strncmp(cur, suffix, strlen(suffix))) {
1773 pr_warn("crashkernel: unrecognized char\n");
1776 cur += strlen(suffix);
1777 if (*cur != ' ' && *cur != '\0') {
1778 pr_warn("crashkernel: unrecognized char\n");
1785 static __init char *get_last_crashkernel(char *cmdline,
1789 char *p = cmdline, *ck_cmdline = NULL;
1791 /* find crashkernel and use the last one if there are more */
1792 p = strstr(p, name);
1794 char *end_p = strchr(p, ' ');
1798 end_p = p + strlen(p);
1803 /* skip the one with any known suffix */
1804 for (i = 0; suffix_tbl[i]; i++) {
1805 q = end_p - strlen(suffix_tbl[i]);
1806 if (!strncmp(q, suffix_tbl[i],
1807 strlen(suffix_tbl[i])))
1812 q = end_p - strlen(suffix);
1813 if (!strncmp(q, suffix, strlen(suffix)))
1817 p = strstr(p+1, name);
1826 static int __init __parse_crashkernel(char *cmdline,
1827 unsigned long long system_ram,
1828 unsigned long long *crash_size,
1829 unsigned long long *crash_base,
1833 char *first_colon, *first_space;
1836 BUG_ON(!crash_size || !crash_base);
1840 ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
1845 ck_cmdline += strlen(name);
1848 return parse_crashkernel_suffix(ck_cmdline, crash_size,
1851 * if the commandline contains a ':', then that's the extended
1852 * syntax -- if not, it must be the classic syntax
1854 first_colon = strchr(ck_cmdline, ':');
1855 first_space = strchr(ck_cmdline, ' ');
1856 if (first_colon && (!first_space || first_colon < first_space))
1857 return parse_crashkernel_mem(ck_cmdline, system_ram,
1858 crash_size, crash_base);
1860 return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
1864 * That function is the entry point for command line parsing and should be
1865 * called from the arch-specific code.
1867 int __init parse_crashkernel(char *cmdline,
1868 unsigned long long system_ram,
1869 unsigned long long *crash_size,
1870 unsigned long long *crash_base)
1872 return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
1873 "crashkernel=", NULL);
1876 int __init parse_crashkernel_high(char *cmdline,
1877 unsigned long long system_ram,
1878 unsigned long long *crash_size,
1879 unsigned long long *crash_base)
1881 return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
1882 "crashkernel=", suffix_tbl[SUFFIX_HIGH]);
1885 int __init parse_crashkernel_low(char *cmdline,
1886 unsigned long long system_ram,
1887 unsigned long long *crash_size,
1888 unsigned long long *crash_base)
1890 return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
1891 "crashkernel=", suffix_tbl[SUFFIX_LOW]);
1894 static void update_vmcoreinfo_note(void)
1896 u32 *buf = vmcoreinfo_note;
1898 if (!vmcoreinfo_size)
1900 buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
1905 void crash_save_vmcoreinfo(void)
1907 vmcoreinfo_append_str("CRASHTIME=%ld\n", get_seconds());
1908 update_vmcoreinfo_note();
1911 void vmcoreinfo_append_str(const char *fmt, ...)
1917 va_start(args, fmt);
1918 r = vscnprintf(buf, sizeof(buf), fmt, args);
1921 r = min(r, vmcoreinfo_max_size - vmcoreinfo_size);
1923 memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
1925 vmcoreinfo_size += r;
1929 * provide an empty default implementation here -- architecture
1930 * code may override this
1932 void __weak arch_crash_save_vmcoreinfo(void)
1935 unsigned long __weak paddr_vmcoreinfo_note(void)
1937 return __pa((unsigned long)(char *)&vmcoreinfo_note);
1940 static int __init crash_save_vmcoreinfo_init(void)
1942 VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
1943 VMCOREINFO_PAGESIZE(PAGE_SIZE);
1945 VMCOREINFO_SYMBOL(init_uts_ns);
1946 VMCOREINFO_SYMBOL(node_online_map);
1948 VMCOREINFO_SYMBOL(swapper_pg_dir);
1950 VMCOREINFO_SYMBOL(_stext);
1951 VMCOREINFO_SYMBOL(vmap_area_list);
1953 #ifndef CONFIG_NEED_MULTIPLE_NODES
1954 VMCOREINFO_SYMBOL(mem_map);
1955 VMCOREINFO_SYMBOL(contig_page_data);
1957 #ifdef CONFIG_SPARSEMEM
1958 VMCOREINFO_SYMBOL(mem_section);
1959 VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
1960 VMCOREINFO_STRUCT_SIZE(mem_section);
1961 VMCOREINFO_OFFSET(mem_section, section_mem_map);
1963 VMCOREINFO_STRUCT_SIZE(page);
1964 VMCOREINFO_STRUCT_SIZE(pglist_data);
1965 VMCOREINFO_STRUCT_SIZE(zone);
1966 VMCOREINFO_STRUCT_SIZE(free_area);
1967 VMCOREINFO_STRUCT_SIZE(list_head);
1968 VMCOREINFO_SIZE(nodemask_t);
1969 VMCOREINFO_OFFSET(page, flags);
1970 VMCOREINFO_OFFSET(page, _count);
1971 VMCOREINFO_OFFSET(page, mapping);
1972 VMCOREINFO_OFFSET(page, lru);
1973 VMCOREINFO_OFFSET(page, _mapcount);
1974 VMCOREINFO_OFFSET(page, private);
1975 VMCOREINFO_OFFSET(pglist_data, node_zones);
1976 VMCOREINFO_OFFSET(pglist_data, nr_zones);
1977 #ifdef CONFIG_FLAT_NODE_MEM_MAP
1978 VMCOREINFO_OFFSET(pglist_data, node_mem_map);
1980 VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
1981 VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
1982 VMCOREINFO_OFFSET(pglist_data, node_id);
1983 VMCOREINFO_OFFSET(zone, free_area);
1984 VMCOREINFO_OFFSET(zone, vm_stat);
1985 VMCOREINFO_OFFSET(zone, spanned_pages);
1986 VMCOREINFO_OFFSET(free_area, free_list);
1987 VMCOREINFO_OFFSET(list_head, next);
1988 VMCOREINFO_OFFSET(list_head, prev);
1989 VMCOREINFO_OFFSET(vmap_area, va_start);
1990 VMCOREINFO_OFFSET(vmap_area, list);
1991 VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
1992 log_buf_kexec_setup();
1993 VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
1994 VMCOREINFO_NUMBER(NR_FREE_PAGES);
1995 VMCOREINFO_NUMBER(PG_lru);
1996 VMCOREINFO_NUMBER(PG_private);
1997 VMCOREINFO_NUMBER(PG_swapcache);
1998 VMCOREINFO_NUMBER(PG_slab);
1999 #ifdef CONFIG_MEMORY_FAILURE
2000 VMCOREINFO_NUMBER(PG_hwpoison);
2002 VMCOREINFO_NUMBER(PG_head_mask);
2003 VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
2004 #ifdef CONFIG_HUGETLBFS
2005 VMCOREINFO_SYMBOL(free_huge_page);
2008 arch_crash_save_vmcoreinfo();
2009 update_vmcoreinfo_note();
2014 subsys_initcall(crash_save_vmcoreinfo_init);
2016 #ifdef CONFIG_KEXEC_FILE
2017 static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
2018 struct kexec_buf *kbuf)
2020 struct kimage *image = kbuf->image;
2021 unsigned long temp_start, temp_end;
2023 temp_end = min(end, kbuf->buf_max);
2024 temp_start = temp_end - kbuf->memsz;
2027 /* align down start */
2028 temp_start = temp_start & (~(kbuf->buf_align - 1));
2030 if (temp_start < start || temp_start < kbuf->buf_min)
2033 temp_end = temp_start + kbuf->memsz - 1;
2036 * Make sure this does not conflict with any of existing
2039 if (kimage_is_destination_range(image, temp_start, temp_end)) {
2040 temp_start = temp_start - PAGE_SIZE;
2044 /* We found a suitable memory range */
2048 /* If we are here, we found a suitable memory range */
2049 kbuf->mem = temp_start;
2051 /* Success, stop navigating through remaining System RAM ranges */
2055 static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
2056 struct kexec_buf *kbuf)
2058 struct kimage *image = kbuf->image;
2059 unsigned long temp_start, temp_end;
2061 temp_start = max(start, kbuf->buf_min);
2064 temp_start = ALIGN(temp_start, kbuf->buf_align);
2065 temp_end = temp_start + kbuf->memsz - 1;
2067 if (temp_end > end || temp_end > kbuf->buf_max)
2070 * Make sure this does not conflict with any of existing
2073 if (kimage_is_destination_range(image, temp_start, temp_end)) {
2074 temp_start = temp_start + PAGE_SIZE;
2078 /* We found a suitable memory range */
2082 /* If we are here, we found a suitable memory range */
2083 kbuf->mem = temp_start;
2085 /* Success, stop navigating through remaining System RAM ranges */
2089 static int locate_mem_hole_callback(u64 start, u64 end, void *arg)
2091 struct kexec_buf *kbuf = (struct kexec_buf *)arg;
2092 unsigned long sz = end - start + 1;
2094 /* Returning 0 will take to next memory range */
2095 if (sz < kbuf->memsz)
2098 if (end < kbuf->buf_min || start > kbuf->buf_max)
2102 * Allocate memory top down with-in ram range. Otherwise bottom up
2106 return locate_mem_hole_top_down(start, end, kbuf);
2107 return locate_mem_hole_bottom_up(start, end, kbuf);
2111 * Helper function for placing a buffer in a kexec segment. This assumes
2112 * that kexec_mutex is held.
2114 int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
2115 unsigned long memsz, unsigned long buf_align,
2116 unsigned long buf_min, unsigned long buf_max,
2117 bool top_down, unsigned long *load_addr)
2120 struct kexec_segment *ksegment;
2121 struct kexec_buf buf, *kbuf;
2124 /* Currently adding segment this way is allowed only in file mode */
2125 if (!image->file_mode)
2128 if (image->nr_segments >= KEXEC_SEGMENT_MAX)
2132 * Make sure we are not trying to add buffer after allocating
2133 * control pages. All segments need to be placed first before
2134 * any control pages are allocated. As control page allocation
2135 * logic goes through list of segments to make sure there are
2136 * no destination overlaps.
2138 if (!list_empty(&image->control_pages)) {
2143 memset(&buf, 0, sizeof(struct kexec_buf));
2145 kbuf->image = image;
2146 kbuf->buffer = buffer;
2147 kbuf->bufsz = bufsz;
2149 kbuf->memsz = ALIGN(memsz, PAGE_SIZE);
2150 kbuf->buf_align = max(buf_align, PAGE_SIZE);
2151 kbuf->buf_min = buf_min;
2152 kbuf->buf_max = buf_max;
2153 kbuf->top_down = top_down;
2155 /* Walk the RAM ranges and allocate a suitable range for the buffer */
2156 if (image->type == KEXEC_TYPE_CRASH)
2157 ret = walk_iomem_res("Crash kernel",
2158 IORESOURCE_MEM | IORESOURCE_BUSY,
2159 crashk_res.start, crashk_res.end, kbuf,
2160 locate_mem_hole_callback);
2162 ret = walk_system_ram_res(0, -1, kbuf,
2163 locate_mem_hole_callback);
2165 /* A suitable memory range could not be found for buffer */
2166 return -EADDRNOTAVAIL;
2169 /* Found a suitable memory range */
2170 ksegment = &image->segment[image->nr_segments];
2171 ksegment->kbuf = kbuf->buffer;
2172 ksegment->bufsz = kbuf->bufsz;
2173 ksegment->mem = kbuf->mem;
2174 ksegment->memsz = kbuf->memsz;
2175 image->nr_segments++;
2176 *load_addr = ksegment->mem;
2180 /* Calculate and store the digest of segments */
2181 static int kexec_calculate_store_digests(struct kimage *image)
2183 struct crypto_shash *tfm;
2184 struct shash_desc *desc;
2185 int ret = 0, i, j, zero_buf_sz, sha_region_sz;
2186 size_t desc_size, nullsz;
2189 struct kexec_sha_region *sha_regions;
2190 struct purgatory_info *pi = &image->purgatory_info;
2192 zero_buf = __va(page_to_pfn(ZERO_PAGE(0)) << PAGE_SHIFT);
2193 zero_buf_sz = PAGE_SIZE;
2195 tfm = crypto_alloc_shash("sha256", 0, 0);
2201 desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
2202 desc = kzalloc(desc_size, GFP_KERNEL);
2208 sha_region_sz = KEXEC_SEGMENT_MAX * sizeof(struct kexec_sha_region);
2209 sha_regions = vzalloc(sha_region_sz);
2216 ret = crypto_shash_init(desc);
2218 goto out_free_sha_regions;
2220 digest = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
2223 goto out_free_sha_regions;
2226 for (j = i = 0; i < image->nr_segments; i++) {
2227 struct kexec_segment *ksegment;
2229 ksegment = &image->segment[i];
2231 * Skip purgatory as it will be modified once we put digest
2232 * info in purgatory.
2234 if (ksegment->kbuf == pi->purgatory_buf)
2237 ret = crypto_shash_update(desc, ksegment->kbuf,
2243 * Assume rest of the buffer is filled with zero and
2244 * update digest accordingly.
2246 nullsz = ksegment->memsz - ksegment->bufsz;
2248 unsigned long bytes = nullsz;
2250 if (bytes > zero_buf_sz)
2251 bytes = zero_buf_sz;
2252 ret = crypto_shash_update(desc, zero_buf, bytes);
2261 sha_regions[j].start = ksegment->mem;
2262 sha_regions[j].len = ksegment->memsz;
2267 ret = crypto_shash_final(desc, digest);
2269 goto out_free_digest;
2270 ret = kexec_purgatory_get_set_symbol(image, "sha_regions",
2271 sha_regions, sha_region_sz, 0);
2273 goto out_free_digest;
2275 ret = kexec_purgatory_get_set_symbol(image, "sha256_digest",
2276 digest, SHA256_DIGEST_SIZE, 0);
2278 goto out_free_digest;
2283 out_free_sha_regions:
2293 /* Actually load purgatory. Lot of code taken from kexec-tools */
2294 static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
2295 unsigned long max, int top_down)
2297 struct purgatory_info *pi = &image->purgatory_info;
2298 unsigned long align, buf_align, bss_align, buf_sz, bss_sz, bss_pad;
2299 unsigned long memsz, entry, load_addr, curr_load_addr, bss_addr, offset;
2300 unsigned char *buf_addr, *src;
2301 int i, ret = 0, entry_sidx = -1;
2302 const Elf_Shdr *sechdrs_c;
2303 Elf_Shdr *sechdrs = NULL;
2304 void *purgatory_buf = NULL;
2307 * sechdrs_c points to section headers in purgatory and are read
2308 * only. No modifications allowed.
2310 sechdrs_c = (void *)pi->ehdr + pi->ehdr->e_shoff;
2313 * We can not modify sechdrs_c[] and its fields. It is read only.
2314 * Copy it over to a local copy where one can store some temporary
2315 * data and free it at the end. We need to modify ->sh_addr and
2316 * ->sh_offset fields to keep track of permanent and temporary
2317 * locations of sections.
2319 sechdrs = vzalloc(pi->ehdr->e_shnum * sizeof(Elf_Shdr));
2323 memcpy(sechdrs, sechdrs_c, pi->ehdr->e_shnum * sizeof(Elf_Shdr));
2326 * We seem to have multiple copies of sections. First copy is which
2327 * is embedded in kernel in read only section. Some of these sections
2328 * will be copied to a temporary buffer and relocated. And these
2329 * sections will finally be copied to their final destination at
2330 * segment load time.
2332 * Use ->sh_offset to reflect section address in memory. It will
2333 * point to original read only copy if section is not allocatable.
2334 * Otherwise it will point to temporary copy which will be relocated.
2336 * Use ->sh_addr to contain final address of the section where it
2337 * will go during execution time.
2339 for (i = 0; i < pi->ehdr->e_shnum; i++) {
2340 if (sechdrs[i].sh_type == SHT_NOBITS)
2343 sechdrs[i].sh_offset = (unsigned long)pi->ehdr +
2344 sechdrs[i].sh_offset;
2348 * Identify entry point section and make entry relative to section
2351 entry = pi->ehdr->e_entry;
2352 for (i = 0; i < pi->ehdr->e_shnum; i++) {
2353 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
2356 if (!(sechdrs[i].sh_flags & SHF_EXECINSTR))
2359 /* Make entry section relative */
2360 if (sechdrs[i].sh_addr <= pi->ehdr->e_entry &&
2361 ((sechdrs[i].sh_addr + sechdrs[i].sh_size) >
2362 pi->ehdr->e_entry)) {
2364 entry -= sechdrs[i].sh_addr;
2369 /* Determine how much memory is needed to load relocatable object. */
2375 for (i = 0; i < pi->ehdr->e_shnum; i++) {
2376 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
2379 align = sechdrs[i].sh_addralign;
2380 if (sechdrs[i].sh_type != SHT_NOBITS) {
2381 if (buf_align < align)
2383 buf_sz = ALIGN(buf_sz, align);
2384 buf_sz += sechdrs[i].sh_size;
2387 if (bss_align < align)
2389 bss_sz = ALIGN(bss_sz, align);
2390 bss_sz += sechdrs[i].sh_size;
2394 /* Determine the bss padding required to align bss properly */
2396 if (buf_sz & (bss_align - 1))
2397 bss_pad = bss_align - (buf_sz & (bss_align - 1));
2399 memsz = buf_sz + bss_pad + bss_sz;
2401 /* Allocate buffer for purgatory */
2402 purgatory_buf = vzalloc(buf_sz);
2403 if (!purgatory_buf) {
2408 if (buf_align < bss_align)
2409 buf_align = bss_align;
2411 /* Add buffer to segment list */
2412 ret = kexec_add_buffer(image, purgatory_buf, buf_sz, memsz,
2413 buf_align, min, max, top_down,
2414 &pi->purgatory_load_addr);
2418 /* Load SHF_ALLOC sections */
2419 buf_addr = purgatory_buf;
2420 load_addr = curr_load_addr = pi->purgatory_load_addr;
2421 bss_addr = load_addr + buf_sz + bss_pad;
2423 for (i = 0; i < pi->ehdr->e_shnum; i++) {
2424 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
2427 align = sechdrs[i].sh_addralign;
2428 if (sechdrs[i].sh_type != SHT_NOBITS) {
2429 curr_load_addr = ALIGN(curr_load_addr, align);
2430 offset = curr_load_addr - load_addr;
2431 /* We already modifed ->sh_offset to keep src addr */
2432 src = (char *) sechdrs[i].sh_offset;
2433 memcpy(buf_addr + offset, src, sechdrs[i].sh_size);
2435 /* Store load address and source address of section */
2436 sechdrs[i].sh_addr = curr_load_addr;
2439 * This section got copied to temporary buffer. Update
2440 * ->sh_offset accordingly.
2442 sechdrs[i].sh_offset = (unsigned long)(buf_addr + offset);
2444 /* Advance to the next address */
2445 curr_load_addr += sechdrs[i].sh_size;
2447 bss_addr = ALIGN(bss_addr, align);
2448 sechdrs[i].sh_addr = bss_addr;
2449 bss_addr += sechdrs[i].sh_size;
2453 /* Update entry point based on load address of text section */
2454 if (entry_sidx >= 0)
2455 entry += sechdrs[entry_sidx].sh_addr;
2457 /* Make kernel jump to purgatory after shutdown */
2458 image->start = entry;
2460 /* Used later to get/set symbol values */
2461 pi->sechdrs = sechdrs;
2464 * Used later to identify which section is purgatory and skip it
2465 * from checksumming.
2467 pi->purgatory_buf = purgatory_buf;
2471 vfree(purgatory_buf);
2475 static int kexec_apply_relocations(struct kimage *image)
2478 struct purgatory_info *pi = &image->purgatory_info;
2479 Elf_Shdr *sechdrs = pi->sechdrs;
2481 /* Apply relocations */
2482 for (i = 0; i < pi->ehdr->e_shnum; i++) {
2483 Elf_Shdr *section, *symtab;
2485 if (sechdrs[i].sh_type != SHT_RELA &&
2486 sechdrs[i].sh_type != SHT_REL)
2490 * For section of type SHT_RELA/SHT_REL,
2491 * ->sh_link contains section header index of associated
2492 * symbol table. And ->sh_info contains section header
2493 * index of section to which relocations apply.
2495 if (sechdrs[i].sh_info >= pi->ehdr->e_shnum ||
2496 sechdrs[i].sh_link >= pi->ehdr->e_shnum)
2499 section = &sechdrs[sechdrs[i].sh_info];
2500 symtab = &sechdrs[sechdrs[i].sh_link];
2502 if (!(section->sh_flags & SHF_ALLOC))
2506 * symtab->sh_link contain section header index of associated
2509 if (symtab->sh_link >= pi->ehdr->e_shnum)
2510 /* Invalid section number? */
2514 * Respective architecture needs to provide support for applying
2515 * relocations of type SHT_RELA/SHT_REL.
2517 if (sechdrs[i].sh_type == SHT_RELA)
2518 ret = arch_kexec_apply_relocations_add(pi->ehdr,
2520 else if (sechdrs[i].sh_type == SHT_REL)
2521 ret = arch_kexec_apply_relocations(pi->ehdr,
2530 /* Load relocatable purgatory object and relocate it appropriately */
2531 int kexec_load_purgatory(struct kimage *image, unsigned long min,
2532 unsigned long max, int top_down,
2533 unsigned long *load_addr)
2535 struct purgatory_info *pi = &image->purgatory_info;
2538 if (kexec_purgatory_size <= 0)
2541 if (kexec_purgatory_size < sizeof(Elf_Ehdr))
2544 pi->ehdr = (Elf_Ehdr *)kexec_purgatory;
2546 if (memcmp(pi->ehdr->e_ident, ELFMAG, SELFMAG) != 0
2547 || pi->ehdr->e_type != ET_REL
2548 || !elf_check_arch(pi->ehdr)
2549 || pi->ehdr->e_shentsize != sizeof(Elf_Shdr))
2552 if (pi->ehdr->e_shoff >= kexec_purgatory_size
2553 || (pi->ehdr->e_shnum * sizeof(Elf_Shdr) >
2554 kexec_purgatory_size - pi->ehdr->e_shoff))
2557 ret = __kexec_load_purgatory(image, min, max, top_down);
2561 ret = kexec_apply_relocations(image);
2565 *load_addr = pi->purgatory_load_addr;
2569 vfree(pi->purgatory_buf);
2573 static Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
2582 if (!pi->sechdrs || !pi->ehdr)
2585 sechdrs = pi->sechdrs;
2588 for (i = 0; i < ehdr->e_shnum; i++) {
2589 if (sechdrs[i].sh_type != SHT_SYMTAB)
2592 if (sechdrs[i].sh_link >= ehdr->e_shnum)
2593 /* Invalid strtab section number */
2595 strtab = (char *)sechdrs[sechdrs[i].sh_link].sh_offset;
2596 syms = (Elf_Sym *)sechdrs[i].sh_offset;
2598 /* Go through symbols for a match */
2599 for (k = 0; k < sechdrs[i].sh_size/sizeof(Elf_Sym); k++) {
2600 if (ELF_ST_BIND(syms[k].st_info) != STB_GLOBAL)
2603 if (strcmp(strtab + syms[k].st_name, name) != 0)
2606 if (syms[k].st_shndx == SHN_UNDEF ||
2607 syms[k].st_shndx >= ehdr->e_shnum) {
2608 pr_debug("Symbol: %s has bad section index %d.\n",
2609 name, syms[k].st_shndx);
2613 /* Found the symbol we are looking for */
2621 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name)
2623 struct purgatory_info *pi = &image->purgatory_info;
2627 sym = kexec_purgatory_find_symbol(pi, name);
2629 return ERR_PTR(-EINVAL);
2631 sechdr = &pi->sechdrs[sym->st_shndx];
2634 * Returns the address where symbol will finally be loaded after
2635 * kexec_load_segment()
2637 return (void *)(sechdr->sh_addr + sym->st_value);
2641 * Get or set value of a symbol. If "get_value" is true, symbol value is
2642 * returned in buf otherwise symbol value is set based on value in buf.
2644 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
2645 void *buf, unsigned int size, bool get_value)
2649 struct purgatory_info *pi = &image->purgatory_info;
2652 sym = kexec_purgatory_find_symbol(pi, name);
2656 if (sym->st_size != size) {
2657 pr_err("symbol %s size mismatch: expected %lu actual %u\n",
2658 name, (unsigned long)sym->st_size, size);
2662 sechdrs = pi->sechdrs;
2664 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2665 pr_err("symbol %s is in a bss section. Cannot %s\n", name,
2666 get_value ? "get" : "set");
2670 sym_buf = (unsigned char *)sechdrs[sym->st_shndx].sh_offset +
2674 memcpy((void *)buf, sym_buf, size);
2676 memcpy((void *)sym_buf, buf, size);
2680 #endif /* CONFIG_KEXEC_FILE */
2683 * Move into place and start executing a preloaded standalone
2684 * executable. If nothing was preloaded return an error.
2686 int kernel_kexec(void)
2690 if (!mutex_trylock(&kexec_mutex))
2697 #ifdef CONFIG_KEXEC_JUMP
2698 if (kexec_image->preserve_context) {
2699 lock_system_sleep();
2700 pm_prepare_console();
2701 error = freeze_processes();
2704 goto Restore_console;
2707 error = dpm_suspend_start(PMSG_FREEZE);
2709 goto Resume_console;
2710 /* At this point, dpm_suspend_start() has been called,
2711 * but *not* dpm_suspend_end(). We *must* call
2712 * dpm_suspend_end() now. Otherwise, drivers for
2713 * some devices (e.g. interrupt controllers) become
2714 * desynchronized with the actual state of the
2715 * hardware at resume time, and evil weirdness ensues.
2717 error = dpm_suspend_end(PMSG_FREEZE);
2719 goto Resume_devices;
2720 error = disable_nonboot_cpus();
2723 local_irq_disable();
2724 error = syscore_suspend();
2730 kexec_in_progress = true;
2731 kernel_restart_prepare(NULL);
2732 migrate_to_reboot_cpu();
2735 * migrate_to_reboot_cpu() disables CPU hotplug assuming that
2736 * no further code needs to use CPU hotplug (which is true in
2737 * the reboot case). However, the kexec path depends on using
2738 * CPU hotplug again; so re-enable it here.
2740 cpu_hotplug_enable();
2741 pr_emerg("Starting new kernel\n");
2745 machine_kexec(kexec_image);
2747 #ifdef CONFIG_KEXEC_JUMP
2748 if (kexec_image->preserve_context) {
2753 enable_nonboot_cpus();
2754 dpm_resume_start(PMSG_RESTORE);
2756 dpm_resume_end(PMSG_RESTORE);
2761 pm_restore_console();
2762 unlock_system_sleep();
2767 mutex_unlock(&kexec_mutex);