Kernel

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Root/kernel/kexec.c

1	/*
2	* kexec.c - kexec system call
3	* Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com>
4	*
5	* This source code is licensed under the GNU General Public License,
6	* Version 2. See the file COPYING for more details.
7	*/
8
9	#include <linux/capability.h>
10	#include <linux/mm.h>
11	#include <linux/file.h>
12	#include <linux/slab.h>
13	#include <linux/fs.h>
14	#include <linux/kexec.h>
15	#include <linux/mutex.h>
16	#include <linux/list.h>
17	#include <linux/highmem.h>
18	#include <linux/syscalls.h>
19	#include <linux/reboot.h>
20	#include <linux/ioport.h>
21	#include <linux/hardirq.h>
22	#include <linux/elf.h>
23	#include <linux/elfcore.h>
24	#include <generated/utsrelease.h>
25	#include <linux/utsname.h>
26	#include <linux/numa.h>
27	#include <linux/suspend.h>
28	#include <linux/device.h>
29	#include <linux/freezer.h>
30	#include <linux/pm.h>
31	#include <linux/cpu.h>
32	#include <linux/console.h>
33	#include <linux/vmalloc.h>
34	#include <linux/swap.h>
35	#include <linux/kmsg_dump.h>
36
37	#include <asm/page.h>
38	#include <asm/uaccess.h>
39	#include <asm/io.h>
40	#include <asm/system.h>
41	#include <asm/sections.h>
42
43	/* Per cpu memory for storing cpu states in case of system crash. */
44	note_buf_t __percpu *crash_notes;
45
46	/* vmcoreinfo stuff */
47	static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES];
48	u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
49	size_t vmcoreinfo_size;
50	size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data);
51
52	/* Location of the reserved area for the crash kernel */
53	struct resource crashk_res = {
54	.name = "Crash kernel",
55	.start = 0,
56	.end = 0,
57	.flags = IORESOURCE_BUSY \| IORESOURCE_MEM
58	};
59
60	int kexec_should_crash(struct task_struct *p)
61	{
62	if (in_interrupt() \|\| !p->pid \|\| is_global_init(p) \|\| panic_on_oops)
63	return 1;
64	return 0;
65	}
66
67	/*
68	* When kexec transitions to the new kernel there is a one-to-one
69	* mapping between physical and virtual addresses. On processors
70	* where you can disable the MMU this is trivial, and easy. For
71	* others it is still a simple predictable page table to setup.
72	*
73	* In that environment kexec copies the new kernel to its final
74	* resting place. This means I can only support memory whose
75	* physical address can fit in an unsigned long. In particular
76	* addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled.
77	* If the assembly stub has more restrictive requirements
78	* KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be
79	* defined more restrictively in <asm/kexec.h>.
80	*
81	* The code for the transition from the current kernel to the
82	* the new kernel is placed in the control_code_buffer, whose size
83	* is given by KEXEC_CONTROL_PAGE_SIZE. In the best case only a single
84	* page of memory is necessary, but some architectures require more.
85	* Because this memory must be identity mapped in the transition from
86	* virtual to physical addresses it must live in the range
87	* 0 - TASK_SIZE, as only the user space mappings are arbitrarily
88	* modifiable.
89	*
90	* The assembly stub in the control code buffer is passed a linked list
91	* of descriptor pages detailing the source pages of the new kernel,
92	* and the destination addresses of those source pages. As this data
93	* structure is not used in the context of the current OS, it must
94	* be self-contained.
95	*
96	* The code has been made to work with highmem pages and will use a
97	* destination page in its final resting place (if it happens
98	* to allocate it). The end product of this is that most of the
99	* physical address space, and most of RAM can be used.
100	*
101	* Future directions include:
102	* - allocating a page table with the control code buffer identity
103	* mapped, to simplify machine_kexec and make kexec_on_panic more
104	* reliable.
105	*/
106
107	/*
108	* KIMAGE_NO_DEST is an impossible destination address..., for
109	* allocating pages whose destination address we do not care about.
110	*/
111	#define KIMAGE_NO_DEST (-1UL)
112
113	static int kimage_is_destination_range(struct kimage *image,
114	unsigned long start, unsigned long end);
115	static struct page kimage_alloc_page(struct kimage image,
116	gfp_t gfp_mask,
117	unsigned long dest);
118
119	static int do_kimage_alloc(struct kimage **rimage, unsigned long entry,
120	unsigned long nr_segments,
121	struct kexec_segment __user *segments)
122	{
123	size_t segment_bytes;
124	struct kimage *image;
125	unsigned long i;
126	int result;
127
128	/* Allocate a controlling structure */
129	result = -ENOMEM;
130	image = kzalloc(sizeof(*image), GFP_KERNEL);
131	if (!image)
132	goto out;
133
134	image->head = 0;
135	image->entry = &image->head;
136	image->last_entry = &image->head;
137	image->control_page = ~0; /* By default this does not apply */
138	image->start = entry;
139	image->type = KEXEC_TYPE_DEFAULT;
140
141	/* Initialize the list of control pages */
142	INIT_LIST_HEAD(&image->control_pages);
143
144	/* Initialize the list of destination pages */
145	INIT_LIST_HEAD(&image->dest_pages);
146
147	/* Initialize the list of unuseable pages */
148	INIT_LIST_HEAD(&image->unuseable_pages);
149
150	/* Read in the segments */
151	image->nr_segments = nr_segments;
152	segment_bytes = nr_segments * sizeof(*segments);
153	result = copy_from_user(image->segment, segments, segment_bytes);
154	if (result) {
155	result = -EFAULT;
156	goto out;
157	}
158
159	/*
160	* Verify we have good destination addresses. The caller is
161	* responsible for making certain we don't attempt to load
162	* the new image into invalid or reserved areas of RAM. This
163	* just verifies it is an address we can use.
164	*
165	* Since the kernel does everything in page size chunks ensure
166	* the destination addresses are page aligned. Too many
167	* special cases crop of when we don't do this. The most
168	* insidious is getting overlapping destination addresses
169	* simply because addresses are changed to page size
170	* granularity.
171	*/
172	result = -EADDRNOTAVAIL;
173	for (i = 0; i < nr_segments; i++) {
174	unsigned long mstart, mend;
175
176	mstart = image->segment[i].mem;
177	mend = mstart + image->segment[i].memsz;
178	if ((mstart & ~PAGE_MASK) \|\| (mend & ~PAGE_MASK))
179	goto out;
180	if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT)
181	goto out;
182	}
183
184	/* Verify our destination addresses do not overlap.
185	* If we alloed overlapping destination addresses
186	* through very weird things can happen with no
187	* easy explanation as one segment stops on another.
188	*/
189	result = -EINVAL;
190	for (i = 0; i < nr_segments; i++) {
191	unsigned long mstart, mend;
192	unsigned long j;
193
194	mstart = image->segment[i].mem;
195	mend = mstart + image->segment[i].memsz;
196	for (j = 0; j < i; j++) {
197	unsigned long pstart, pend;
198	pstart = image->segment[j].mem;
199	pend = pstart + image->segment[j].memsz;
200	/* Do the segments overlap ? */
201	if ((mend > pstart) && (mstart < pend))
202	goto out;
203	}
204	}
205
206	/* Ensure our buffer sizes are strictly less than
207	* our memory sizes. This should always be the case,
208	* and it is easier to check up front than to be surprised
209	* later on.
210	*/
211	result = -EINVAL;
212	for (i = 0; i < nr_segments; i++) {
213	if (image->segment[i].bufsz > image->segment[i].memsz)
214	goto out;
215	}
216
217	result = 0;
218	out:
219	if (result == 0)
220	*rimage = image;
221	else
222	kfree(image);
223
224	return result;
225
226	}
227
228	static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
229	unsigned long nr_segments,
230	struct kexec_segment __user *segments)
231	{
232	int result;
233	struct kimage *image;
234
235	/* Allocate and initialize a controlling structure */
236	image = NULL;
237	result = do_kimage_alloc(&image, entry, nr_segments, segments);
238	if (result)
239	goto out;
240
241	*rimage = image;
242
243	/*
244	* Find a location for the control code buffer, and add it
245	* the vector of segments so that it's pages will also be
246	* counted as destination pages.
247	*/
248	result = -ENOMEM;
249	image->control_code_page = kimage_alloc_control_pages(image,
250	get_order(KEXEC_CONTROL_PAGE_SIZE));
251	if (!image->control_code_page) {
252	printk(KERN_ERR "Could not allocate control_code_buffer\n");
253	goto out;
254	}
255
256	image->swap_page = kimage_alloc_control_pages(image, 0);
257	if (!image->swap_page) {
258	printk(KERN_ERR "Could not allocate swap buffer\n");
259	goto out;
260	}
261
262	result = 0;
263	out:
264	if (result == 0)
265	*rimage = image;
266	else
267	kfree(image);
268
269	return result;
270	}
271
272	static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
273	unsigned long nr_segments,
274	struct kexec_segment __user *segments)
275	{
276	int result;
277	struct kimage *image;
278	unsigned long i;
279
280	image = NULL;
281	/* Verify we have a valid entry point */
282	if ((entry < crashk_res.start) \|\| (entry > crashk_res.end)) {
283	result = -EADDRNOTAVAIL;
284	goto out;
285	}
286
287	/* Allocate and initialize a controlling structure */
288	result = do_kimage_alloc(&image, entry, nr_segments, segments);
289	if (result)
290	goto out;
291
292	/* Enable the special crash kernel control page
293	* allocation policy.
294	*/
295	image->control_page = crashk_res.start;
296	image->type = KEXEC_TYPE_CRASH;
297
298	/*
299	* Verify we have good destination addresses. Normally
300	* the caller is responsible for making certain we don't
301	* attempt to load the new image into invalid or reserved
302	* areas of RAM. But crash kernels are preloaded into a
303	* reserved area of ram. We must ensure the addresses
304	* are in the reserved area otherwise preloading the
305	* kernel could corrupt things.
306	*/
307	result = -EADDRNOTAVAIL;
308	for (i = 0; i < nr_segments; i++) {
309	unsigned long mstart, mend;
310
311	mstart = image->segment[i].mem;
312	mend = mstart + image->segment[i].memsz - 1;
313	/* Ensure we are within the crash kernel limits */
314	if ((mstart < crashk_res.start) \|\| (mend > crashk_res.end))
315	goto out;
316	}
317
318	/*
319	* Find a location for the control code buffer, and add
320	* the vector of segments so that it's pages will also be
321	* counted as destination pages.
322	*/
323	result = -ENOMEM;
324	image->control_code_page = kimage_alloc_control_pages(image,
325	get_order(KEXEC_CONTROL_PAGE_SIZE));
326	if (!image->control_code_page) {
327	printk(KERN_ERR "Could not allocate control_code_buffer\n");
328	goto out;
329	}
330
331	result = 0;
332	out:
333	if (result == 0)
334	*rimage = image;
335	else
336	kfree(image);
337
338	return result;
339	}
340
341	static int kimage_is_destination_range(struct kimage *image,
342	unsigned long start,
343	unsigned long end)
344	{
345	unsigned long i;
346
347	for (i = 0; i < image->nr_segments; i++) {
348	unsigned long mstart, mend;
349
350	mstart = image->segment[i].mem;
351	mend = mstart + image->segment[i].memsz;
352	if ((end > mstart) && (start < mend))
353	return 1;
354	}
355
356	return 0;
357	}
358
359	static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order)
360	{
361	struct page *pages;
362
363	pages = alloc_pages(gfp_mask, order);
364	if (pages) {
365	unsigned int count, i;
366	pages->mapping = NULL;
367	set_page_private(pages, order);
368	count = 1 << order;
369	for (i = 0; i < count; i++)
370	SetPageReserved(pages + i);
371	}
372
373	return pages;
374	}
375
376	static void kimage_free_pages(struct page *page)
377	{
378	unsigned int order, count, i;
379
380	order = page_private(page);
381	count = 1 << order;
382	for (i = 0; i < count; i++)
383	ClearPageReserved(page + i);
384	__free_pages(page, order);
385	}
386
387	static void kimage_free_page_list(struct list_head *list)
388	{
389	struct list_head pos, next;
390
391	list_for_each_safe(pos, next, list) {
392	struct page *page;
393
394	page = list_entry(pos, struct page, lru);
395	list_del(&page->lru);
396	kimage_free_pages(page);
397	}
398	}
399
400	static struct page kimage_alloc_normal_control_pages(struct kimage image,
401	unsigned int order)
402	{
403	/* Control pages are special, they are the intermediaries
404	* that are needed while we copy the rest of the pages
405	* to their final resting place. As such they must
406	* not conflict with either the destination addresses
407	* or memory the kernel is already using.
408	*
409	* The only case where we really need more than one of
410	* these are for architectures where we cannot disable
411	* the MMU and must instead generate an identity mapped
412	* page table for all of the memory.
413	*
414	* At worst this runs in O(N) of the image size.
415	*/
416	struct list_head extra_pages;
417	struct page *pages;
418	unsigned int count;
419
420	count = 1 << order;
421	INIT_LIST_HEAD(&extra_pages);
422
423	/* Loop while I can allocate a page and the page allocated
424	* is a destination page.
425	*/
426	do {
427	unsigned long pfn, epfn, addr, eaddr;
428
429	pages = kimage_alloc_pages(GFP_KERNEL, order);
430	if (!pages)
431	break;
432	pfn = page_to_pfn(pages);
433	epfn = pfn + count;
434	addr = pfn << PAGE_SHIFT;
435	eaddr = epfn << PAGE_SHIFT;
436	if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) \|\|
437	kimage_is_destination_range(image, addr, eaddr)) {
438	list_add(&pages->lru, &extra_pages);
439	pages = NULL;
440	}
441	} while (!pages);
442
443	if (pages) {
444	/* Remember the allocated page... */
445	list_add(&pages->lru, &image->control_pages);
446
447	/* Because the page is already in it's destination
448	* location we will never allocate another page at
449	* that address. Therefore kimage_alloc_pages
450	* will not return it (again) and we don't need
451	* to give it an entry in image->segment[].
452	*/
453	}
454	/* Deal with the destination pages I have inadvertently allocated.
455	*
456	* Ideally I would convert multi-page allocations into single
457	* page allocations, and add everyting to image->dest_pages.
458	*
459	* For now it is simpler to just free the pages.
460	*/
461	kimage_free_page_list(&extra_pages);
462
463	return pages;
464	}
465
466	static struct page kimage_alloc_crash_control_pages(struct kimage image,
467	unsigned int order)
468	{
469	/* Control pages are special, they are the intermediaries
470	* that are needed while we copy the rest of the pages
471	* to their final resting place. As such they must
472	* not conflict with either the destination addresses
473	* or memory the kernel is already using.
474	*
475	* Control pages are also the only pags we must allocate
476	* when loading a crash kernel. All of the other pages
477	* are specified by the segments and we just memcpy
478	* into them directly.
479	*
480	* The only case where we really need more than one of
481	* these are for architectures where we cannot disable
482	* the MMU and must instead generate an identity mapped
483	* page table for all of the memory.
484	*
485	* Given the low demand this implements a very simple
486	* allocator that finds the first hole of the appropriate
487	* size in the reserved memory region, and allocates all
488	* of the memory up to and including the hole.
489	*/
490	unsigned long hole_start, hole_end, size;
491	struct page *pages;
492
493	pages = NULL;
494	size = (1 << order) << PAGE_SHIFT;
495	hole_start = (image->control_page + (size - 1)) & ~(size - 1);
496	hole_end = hole_start + size - 1;
497	while (hole_end <= crashk_res.end) {
498	unsigned long i;
499
500	if (hole_end > KEXEC_CONTROL_MEMORY_LIMIT)
501	break;
502	if (hole_end > crashk_res.end)
503	break;
504	/* See if I overlap any of the segments */
505	for (i = 0; i < image->nr_segments; i++) {
506	unsigned long mstart, mend;
507
508	mstart = image->segment[i].mem;
509	mend = mstart + image->segment[i].memsz - 1;
510	if ((hole_end >= mstart) && (hole_start <= mend)) {
511	/* Advance the hole to the end of the segment */
512	hole_start = (mend + (size - 1)) & ~(size - 1);
513	hole_end = hole_start + size - 1;
514	break;
515	}
516	}
517	/* If I don't overlap any segments I have found my hole! */
518	if (i == image->nr_segments) {
519	pages = pfn_to_page(hole_start >> PAGE_SHIFT);
520	break;
521	}
522	}
523	if (pages)
524	image->control_page = hole_end;
525
526	return pages;
527	}
528
529
530	struct page kimage_alloc_control_pages(struct kimage image,
531	unsigned int order)
532	{
533	struct page *pages = NULL;
534
535	switch (image->type) {
536	case KEXEC_TYPE_DEFAULT:
537	pages = kimage_alloc_normal_control_pages(image, order);
538	break;
539	case KEXEC_TYPE_CRASH:
540	pages = kimage_alloc_crash_control_pages(image, order);
541	break;
542	}
543
544	return pages;
545	}
546
547	static int kimage_add_entry(struct kimage *image, kimage_entry_t entry)
548	{
549	if (*image->entry != 0)
550	image->entry++;
551
552	if (image->entry == image->last_entry) {
553	kimage_entry_t *ind_page;
554	struct page *page;
555
556	page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST);
557	if (!page)
558	return -ENOMEM;
559
560	ind_page = page_address(page);
561	*image->entry = virt_to_phys(ind_page) \| IND_INDIRECTION;
562	image->entry = ind_page;
563	image->last_entry = ind_page +
564	((PAGE_SIZE/sizeof(kimage_entry_t)) - 1);
565	}
566	*image->entry = entry;
567	image->entry++;
568	*image->entry = 0;
569
570	return 0;
571	}
572
573	static int kimage_set_destination(struct kimage *image,
574	unsigned long destination)
575	{
576	int result;
577
578	destination &= PAGE_MASK;
579	result = kimage_add_entry(image, destination \| IND_DESTINATION);
580	if (result == 0)
581	image->destination = destination;
582
583	return result;
584	}
585
586
587	static int kimage_add_page(struct kimage *image, unsigned long page)
588	{
589	int result;
590
591	page &= PAGE_MASK;
592	result = kimage_add_entry(image, page \| IND_SOURCE);
593	if (result == 0)
594	image->destination += PAGE_SIZE;
595
596	return result;
597	}
598
599
600	static void kimage_free_extra_pages(struct kimage *image)
601	{
602	/* Walk through and free any extra destination pages I may have */
603	kimage_free_page_list(&image->dest_pages);
604
605	/* Walk through and free any unuseable pages I have cached */
606	kimage_free_page_list(&image->unuseable_pages);
607
608	}
609	static void kimage_terminate(struct kimage *image)
610	{
611	if (*image->entry != 0)
612	image->entry++;
613
614	*image->entry = IND_DONE;
615	}
616
617	#define for_each_kimage_entry(image, ptr, entry) \
618	for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \
619	ptr = (entry & IND_INDIRECTION)? \
620	phys_to_virt((entry & PAGE_MASK)): ptr +1)
621
622	static void kimage_free_entry(kimage_entry_t entry)
623	{
624	struct page *page;
625
626	page = pfn_to_page(entry >> PAGE_SHIFT);
627	kimage_free_pages(page);
628	}
629
630	static void kimage_free(struct kimage *image)
631	{
632	kimage_entry_t *ptr, entry;
633	kimage_entry_t ind = 0;
634
635	if (!image)
636	return;
637
638	kimage_free_extra_pages(image);
639	for_each_kimage_entry(image, ptr, entry) {
640	if (entry & IND_INDIRECTION) {
641	/* Free the previous indirection page */
642	if (ind & IND_INDIRECTION)
643	kimage_free_entry(ind);
644	/* Save this indirection page until we are
645	* done with it.
646	*/
647	ind = entry;
648	}
649	else if (entry & IND_SOURCE)
650	kimage_free_entry(entry);
651	}
652	/* Free the final indirection page */
653	if (ind & IND_INDIRECTION)
654	kimage_free_entry(ind);
655
656	/* Handle any machine specific cleanup */
657	machine_kexec_cleanup(image);
658
659	/* Free the kexec control pages... */
660	kimage_free_page_list(&image->control_pages);
661	kfree(image);
662	}
663
664	static kimage_entry_t kimage_dst_used(struct kimage image,
665	unsigned long page)
666	{
667	kimage_entry_t *ptr, entry;
668	unsigned long destination = 0;
669
670	for_each_kimage_entry(image, ptr, entry) {
671	if (entry & IND_DESTINATION)
672	destination = entry & PAGE_MASK;
673	else if (entry & IND_SOURCE) {
674	if (page == destination)
675	return ptr;
676	destination += PAGE_SIZE;
677	}
678	}
679
680	return NULL;
681	}
682
683	static struct page kimage_alloc_page(struct kimage image,
684	gfp_t gfp_mask,
685	unsigned long destination)
686	{
687	/*
688	* Here we implement safeguards to ensure that a source page
689	* is not copied to its destination page before the data on
690	* the destination page is no longer useful.
691	*
692	* To do this we maintain the invariant that a source page is
693	* either its own destination page, or it is not a
694	* destination page at all.
695	*
696	* That is slightly stronger than required, but the proof
697	* that no problems will not occur is trivial, and the
698	* implementation is simply to verify.
699	*
700	* When allocating all pages normally this algorithm will run
701	* in O(N) time, but in the worst case it will run in O(N^2)
702	* time. If the runtime is a problem the data structures can
703	* be fixed.
704	*/
705	struct page *page;
706	unsigned long addr;
707
708	/*
709	* Walk through the list of destination pages, and see if I
710	* have a match.
711	*/
712	list_for_each_entry(page, &image->dest_pages, lru) {
713	addr = page_to_pfn(page) << PAGE_SHIFT;
714	if (addr == destination) {
715	list_del(&page->lru);
716	return page;
717	}
718	}
719	page = NULL;
720	while (1) {
721	kimage_entry_t *old;
722
723	/* Allocate a page, if we run out of memory give up */
724	page = kimage_alloc_pages(gfp_mask, 0);
725	if (!page)
726	return NULL;
727	/* If the page cannot be used file it away */
728	if (page_to_pfn(page) >
729	(KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
730	list_add(&page->lru, &image->unuseable_pages);
731	continue;
732	}
733	addr = page_to_pfn(page) << PAGE_SHIFT;
734
735	/* If it is the destination page we want use it */
736	if (addr == destination)
737	break;
738
739	/* If the page is not a destination page use it */
740	if (!kimage_is_destination_range(image, addr,
741	addr + PAGE_SIZE))
742	break;
743
744	/*
745	* I know that the page is someones destination page.
746	* See if there is already a source page for this
747	* destination page. And if so swap the source pages.
748	*/
749	old = kimage_dst_used(image, addr);
750	if (old) {
751	/* If so move it */
752	unsigned long old_addr;
753	struct page *old_page;
754
755	old_addr = *old & PAGE_MASK;
756	old_page = pfn_to_page(old_addr >> PAGE_SHIFT);
757	copy_highpage(page, old_page);
758	old = addr \| (old & ~PAGE_MASK);
759
760	/* The old page I have found cannot be a
761	* destination page, so return it if it's
762	* gfp_flags honor the ones passed in.
763	*/
764	if (!(gfp_mask & __GFP_HIGHMEM) &&
765	PageHighMem(old_page)) {
766	kimage_free_pages(old_page);
767	continue;
768	}
769	addr = old_addr;
770	page = old_page;
771	break;
772	}
773	else {
774	/* Place the page on the destination list I
775	* will use it later.
776	*/
777	list_add(&page->lru, &image->dest_pages);
778	}
779	}
780
781	return page;
782	}
783
784	static int kimage_load_normal_segment(struct kimage *image,
785	struct kexec_segment *segment)
786	{
787	unsigned long maddr;
788	unsigned long ubytes, mbytes;
789	int result;
790	unsigned char __user *buf;
791
792	result = 0;
793	buf = segment->buf;
794	ubytes = segment->bufsz;
795	mbytes = segment->memsz;
796	maddr = segment->mem;
797
798	result = kimage_set_destination(image, maddr);
799	if (result < 0)
800	goto out;
801
802	while (mbytes) {
803	struct page *page;
804	char *ptr;
805	size_t uchunk, mchunk;
806
807	page = kimage_alloc_page(image, GFP_HIGHUSER, maddr);
808	if (!page) {
809	result = -ENOMEM;
810	goto out;
811	}
812	result = kimage_add_page(image, page_to_pfn(page)
813	<< PAGE_SHIFT);
814	if (result < 0)
815	goto out;
816
817	ptr = kmap(page);
818	/* Start with a clear page */
819	clear_page(ptr);
820	ptr += maddr & ~PAGE_MASK;
821	mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
822	if (mchunk > mbytes)
823	mchunk = mbytes;
824
825	uchunk = mchunk;
826	if (uchunk > ubytes)
827	uchunk = ubytes;
828
829	result = copy_from_user(ptr, buf, uchunk);
830	kunmap(page);
831	if (result) {
832	result = -EFAULT;
833	goto out;
834	}
835	ubytes -= uchunk;
836	maddr += mchunk;
837	buf += mchunk;
838	mbytes -= mchunk;
839	}
840	out:
841	return result;
842	}
843
844	static int kimage_load_crash_segment(struct kimage *image,
845	struct kexec_segment *segment)
846	{
847	/* For crash dumps kernels we simply copy the data from
848	* user space to it's destination.
849	* We do things a page at a time for the sake of kmap.
850	*/
851	unsigned long maddr;
852	unsigned long ubytes, mbytes;
853	int result;
854	unsigned char __user *buf;
855
856	result = 0;
857	buf = segment->buf;
858	ubytes = segment->bufsz;
859	mbytes = segment->memsz;
860	maddr = segment->mem;
861	while (mbytes) {
862	struct page *page;
863	char *ptr;
864	size_t uchunk, mchunk;
865
866	page = pfn_to_page(maddr >> PAGE_SHIFT);
867	if (!page) {
868	result = -ENOMEM;
869	goto out;
870	}
871	ptr = kmap(page);
872	ptr += maddr & ~PAGE_MASK;
873	mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
874	if (mchunk > mbytes)
875	mchunk = mbytes;
876
877	uchunk = mchunk;
878	if (uchunk > ubytes) {
879	uchunk = ubytes;
880	/* Zero the trailing part of the page */
881	memset(ptr + uchunk, 0, mchunk - uchunk);
882	}
883	result = copy_from_user(ptr, buf, uchunk);
884	kexec_flush_icache_page(page);
885	kunmap(page);
886	if (result) {
887	result = -EFAULT;
888	goto out;
889	}
890	ubytes -= uchunk;
891	maddr += mchunk;
892	buf += mchunk;
893	mbytes -= mchunk;
894	}
895	out:
896	return result;
897	}
898
899	static int kimage_load_segment(struct kimage *image,
900	struct kexec_segment *segment)
901	{
902	int result = -ENOMEM;
903
904	switch (image->type) {
905	case KEXEC_TYPE_DEFAULT:
906	result = kimage_load_normal_segment(image, segment);
907	break;
908	case KEXEC_TYPE_CRASH:
909	result = kimage_load_crash_segment(image, segment);
910	break;
911	}
912
913	return result;
914	}
915
916	/*
917	* Exec Kernel system call: for obvious reasons only root may call it.
918	*
919	* This call breaks up into three pieces.
920	* - A generic part which loads the new kernel from the current
921	* address space, and very carefully places the data in the
922	* allocated pages.
923	*
924	* - A generic part that interacts with the kernel and tells all of
925	* the devices to shut down. Preventing on-going dmas, and placing
926	* the devices in a consistent state so a later kernel can
927	* reinitialize them.
928	*
929	* - A machine specific part that includes the syscall number
930	* and the copies the image to it's final destination. And
931	* jumps into the image at entry.
932	*
933	* kexec does not sync, or unmount filesystems so if you need
934	* that to happen you need to do that yourself.
935	*/
936	struct kimage *kexec_image;
937	struct kimage *kexec_crash_image;
938
939	static DEFINE_MUTEX(kexec_mutex);
940
941	SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
942	struct kexec_segment __user *, segments, unsigned long, flags)
943	{
944	struct kimage *dest_image, image;
945	int result;
946
947	/* We only trust the superuser with rebooting the system. */
948	if (!capable(CAP_SYS_BOOT))
949	return -EPERM;
950
951	/*
952	* Verify we have a legal set of flags
953	* This leaves us room for future extensions.
954	*/
955	if ((flags & KEXEC_FLAGS) != (flags & ~KEXEC_ARCH_MASK))
956	return -EINVAL;
957
958	/* Verify we are on the appropriate architecture */
959	if (((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH) &&
960	((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT))
961	return -EINVAL;
962
963	/* Put an artificial cap on the number
964	* of segments passed to kexec_load.
965	*/
966	if (nr_segments > KEXEC_SEGMENT_MAX)
967	return -EINVAL;
968
969	image = NULL;
970	result = 0;
971
972	/* Because we write directly to the reserved memory
973	* region when loading crash kernels we need a mutex here to
974	* prevent multiple crash kernels from attempting to load
975	* simultaneously, and to prevent a crash kernel from loading
976	* over the top of a in use crash kernel.
977	*
978	* KISS: always take the mutex.
979	*/
980	if (!mutex_trylock(&kexec_mutex))
981	return -EBUSY;
982
983	dest_image = &kexec_image;
984	if (flags & KEXEC_ON_CRASH)
985	dest_image = &kexec_crash_image;
986	if (nr_segments > 0) {
987	unsigned long i;
988
989	/* Loading another kernel to reboot into */
990	if ((flags & KEXEC_ON_CRASH) == 0)
991	result = kimage_normal_alloc(&image, entry,
992	nr_segments, segments);
993	/* Loading another kernel to switch to if this one crashes */
994	else if (flags & KEXEC_ON_CRASH) {
995	/* Free any current crash dump kernel before
996	* we corrupt it.
997	*/
998	kimage_free(xchg(&kexec_crash_image, NULL));
999	result = kimage_crash_alloc(&image, entry,
1000	nr_segments, segments);
1001	}
1002	if (result)
1003	goto out;
1004
1005	if (flags & KEXEC_PRESERVE_CONTEXT)
1006	image->preserve_context = 1;
1007	result = machine_kexec_prepare(image);
1008	if (result)
1009	goto out;
1010
1011	for (i = 0; i < nr_segments; i++) {
1012	result = kimage_load_segment(image, &image->segment[i]);
1013	if (result)
1014	goto out;
1015	}
1016	kimage_terminate(image);
1017	}
1018	/* Install the new kernel, and Uninstall the old */
1019	image = xchg(dest_image, image);
1020
1021	out:
1022	mutex_unlock(&kexec_mutex);
1023	kimage_free(image);
1024
1025	return result;
1026	}
1027
1028	#ifdef CONFIG_COMPAT
1029	asmlinkage long compat_sys_kexec_load(unsigned long entry,
1030	unsigned long nr_segments,
1031	struct compat_kexec_segment __user *segments,
1032	unsigned long flags)
1033	{
1034	struct compat_kexec_segment in;
1035	struct kexec_segment out, __user *ksegments;
1036	unsigned long i, result;
1037
1038	/* Don't allow clients that don't understand the native
1039	* architecture to do anything.
1040	*/
1041	if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT)
1042	return -EINVAL;
1043
1044	if (nr_segments > KEXEC_SEGMENT_MAX)
1045	return -EINVAL;
1046
1047	ksegments = compat_alloc_user_space(nr_segments * sizeof(out));
1048	for (i=0; i < nr_segments; i++) {
1049	result = copy_from_user(&in, &segments[i], sizeof(in));
1050	if (result)
1051	return -EFAULT;
1052
1053	out.buf = compat_ptr(in.buf);
1054	out.bufsz = in.bufsz;
1055	out.mem = in.mem;
1056	out.memsz = in.memsz;
1057
1058	result = copy_to_user(&ksegments[i], &out, sizeof(out));
1059	if (result)
1060	return -EFAULT;
1061	}
1062
1063	return sys_kexec_load(entry, nr_segments, ksegments, flags);
1064	}
1065	#endif
1066
1067	void crash_kexec(struct pt_regs *regs)
1068	{
1069	/* Take the kexec_mutex here to prevent sys_kexec_load
1070	* running on one cpu from replacing the crash kernel
1071	* we are using after a panic on a different cpu.
1072	*
1073	* If the crash kernel was not located in a fixed area
1074	* of memory the xchg(&kexec_crash_image) would be
1075	* sufficient. But since I reuse the memory...
1076	*/
1077	if (mutex_trylock(&kexec_mutex)) {
1078	if (kexec_crash_image) {
1079	struct pt_regs fixed_regs;
1080
1081	kmsg_dump(KMSG_DUMP_KEXEC);
1082
1083	crash_setup_regs(&fixed_regs, regs);
1084	crash_save_vmcoreinfo();
1085	machine_crash_shutdown(&fixed_regs);
1086	machine_kexec(kexec_crash_image);
1087	}
1088	mutex_unlock(&kexec_mutex);
1089	}
1090	}
1091
1092	size_t crash_get_memory_size(void)
1093	{
1094	size_t size = 0;
1095	mutex_lock(&kexec_mutex);
1096	if (crashk_res.end != crashk_res.start)
1097	size = crashk_res.end - crashk_res.start + 1;
1098	mutex_unlock(&kexec_mutex);
1099	return size;
1100	}
1101
1102	static void free_reserved_phys_range(unsigned long begin, unsigned long end)
1103	{
1104	unsigned long addr;
1105
1106	for (addr = begin; addr < end; addr += PAGE_SIZE) {
1107	ClearPageReserved(pfn_to_page(addr >> PAGE_SHIFT));
1108	init_page_count(pfn_to_page(addr >> PAGE_SHIFT));
1109	free_page((unsigned long)__va(addr));
1110	totalram_pages++;
1111	}
1112	}
1113
1114	int crash_shrink_memory(unsigned long new_size)
1115	{
1116	int ret = 0;
1117	unsigned long start, end;
1118
1119	mutex_lock(&kexec_mutex);
1120
1121	if (kexec_crash_image) {
1122	ret = -ENOENT;
1123	goto unlock;
1124	}
1125	start = crashk_res.start;
1126	end = crashk_res.end;
1127
1128	if (new_size >= end - start + 1) {
1129	ret = -EINVAL;
1130	if (new_size == end - start + 1)
1131	ret = 0;
1132	goto unlock;
1133	}
1134
1135	start = roundup(start, PAGE_SIZE);
1136	end = roundup(start + new_size, PAGE_SIZE);
1137
1138	free_reserved_phys_range(end, crashk_res.end);
1139
1140	if ((start == end) && (crashk_res.parent != NULL))
1141	release_resource(&crashk_res);
1142	crashk_res.end = end - 1;
1143
1144	unlock:
1145	mutex_unlock(&kexec_mutex);
1146	return ret;
1147	}
1148
1149	static u32 append_elf_note(u32 buf, char name, unsigned type, void data,
1150	size_t data_len)
1151	{
1152	struct elf_note note;
1153
1154	note.n_namesz = strlen(name) + 1;
1155	note.n_descsz = data_len;
1156	note.n_type = type;
1157	memcpy(buf, &note, sizeof(note));
1158	buf += (sizeof(note) + 3)/4;
1159	memcpy(buf, name, note.n_namesz);
1160	buf += (note.n_namesz + 3)/4;
1161	memcpy(buf, data, note.n_descsz);
1162	buf += (note.n_descsz + 3)/4;
1163
1164	return buf;
1165	}
1166
1167	static void final_note(u32 *buf)
1168	{
1169	struct elf_note note;
1170
1171	note.n_namesz = 0;
1172	note.n_descsz = 0;
1173	note.n_type = 0;
1174	memcpy(buf, &note, sizeof(note));
1175	}
1176
1177	void crash_save_cpu(struct pt_regs *regs, int cpu)
1178	{
1179	struct elf_prstatus prstatus;
1180	u32 *buf;
1181
1182	if ((cpu < 0) \|\| (cpu >= nr_cpu_ids))
1183	return;
1184
1185	/* Using ELF notes here is opportunistic.
1186	* I need a well defined structure format
1187	* for the data I pass, and I need tags
1188	* on the data to indicate what information I have
1189	* squirrelled away. ELF notes happen to provide
1190	* all of that, so there is no need to invent something new.
1191	*/
1192	buf = (u32*)per_cpu_ptr(crash_notes, cpu);
1193	if (!buf)
1194	return;
1195	memset(&prstatus, 0, sizeof(prstatus));
1196	prstatus.pr_pid = current->pid;
1197	elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
1198	buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
1199	&prstatus, sizeof(prstatus));
1200	final_note(buf);
1201	}
1202
1203	static int __init crash_notes_memory_init(void)
1204	{
1205	/* Allocate memory for saving cpu registers. */
1206	crash_notes = alloc_percpu(note_buf_t);
1207	if (!crash_notes) {
1208	printk("Kexec: Memory allocation for saving cpu register"
1209	" states failed\n");
1210	return -ENOMEM;
1211	}
1212	return 0;
1213	}
1214	module_init(crash_notes_memory_init)
1215
1216
1217	/*
1218	* parsing the "crashkernel" commandline
1219	*
1220	* this code is intended to be called from architecture specific code
1221	*/
1222
1223
1224	/*
1225	* This function parses command lines in the format
1226	*
1227	* crashkernel=ramsize-range:size[,...][@offset]
1228	*
1229	* The function returns 0 on success and -EINVAL on failure.
1230	*/
1231	static int __init parse_crashkernel_mem(char *cmdline,
1232	unsigned long long system_ram,
1233	unsigned long long *crash_size,
1234	unsigned long long *crash_base)
1235	{
1236	char cur = cmdline, tmp;
1237
1238	/* for each entry of the comma-separated list */
1239	do {
1240	unsigned long long start, end = ULLONG_MAX, size;
1241
1242	/* get the start of the range */
1243	start = memparse(cur, &tmp);
1244	if (cur == tmp) {
1245	pr_warning("crashkernel: Memory value expected\n");
1246	return -EINVAL;
1247	}
1248	cur = tmp;
1249	if (*cur != '-') {
1250	pr_warning("crashkernel: '-' expected\n");
1251	return -EINVAL;
1252	}
1253	cur++;
1254
1255	/* if no ':' is here, than we read the end */
1256	if (*cur != ':') {
1257	end = memparse(cur, &tmp);
1258	if (cur == tmp) {
1259	pr_warning("crashkernel: Memory "
1260	"value expected\n");
1261	return -EINVAL;
1262	}
1263	cur = tmp;
1264	if (end <= start) {
1265	pr_warning("crashkernel: end <= start\n");
1266	return -EINVAL;
1267	}
1268	}
1269
1270	if (*cur != ':') {
1271	pr_warning("crashkernel: ':' expected\n");
1272	return -EINVAL;
1273	}
1274	cur++;
1275
1276	size = memparse(cur, &tmp);
1277	if (cur == tmp) {
1278	pr_warning("Memory value expected\n");
1279	return -EINVAL;
1280	}
1281	cur = tmp;
1282	if (size >= system_ram) {
1283	pr_warning("crashkernel: invalid size\n");
1284	return -EINVAL;
1285	}
1286
1287	/* match ? */
1288	if (system_ram >= start && system_ram < end) {
1289	*crash_size = size;
1290	break;
1291	}
1292	} while (*cur++ == ',');
1293
1294	if (*crash_size > 0) {
1295	while (cur && cur != ' ' && *cur != '@')
1296	cur++;
1297	if (*cur == '@') {
1298	cur++;
1299	*crash_base = memparse(cur, &tmp);
1300	if (cur == tmp) {
1301	pr_warning("Memory value expected "
1302	"after '@'\n");
1303	return -EINVAL;
1304	}
1305	}
1306	}
1307
1308	return 0;
1309	}
1310
1311	/*
1312	* That function parses "simple" (old) crashkernel command lines like
1313	*
1314	* crashkernel=size[@offset]
1315	*
1316	* It returns 0 on success and -EINVAL on failure.
1317	*/
1318	static int __init parse_crashkernel_simple(char *cmdline,
1319	unsigned long long *crash_size,
1320	unsigned long long *crash_base)
1321	{
1322	char *cur = cmdline;
1323
1324	*crash_size = memparse(cmdline, &cur);
1325	if (cmdline == cur) {
1326	pr_warning("crashkernel: memory value expected\n");
1327	return -EINVAL;
1328	}
1329
1330	if (*cur == '@')
1331	*crash_base = memparse(cur+1, &cur);
1332
1333	return 0;
1334	}
1335
1336	/*
1337	* That function is the entry point for command line parsing and should be
1338	* called from the arch-specific code.
1339	*/
1340	int __init parse_crashkernel(char *cmdline,
1341	unsigned long long system_ram,
1342	unsigned long long *crash_size,
1343	unsigned long long *crash_base)
1344	{
1345	char p = cmdline, ck_cmdline = NULL;
1346	char first_colon, first_space;
1347
1348	BUG_ON(!crash_size \|\| !crash_base);
1349	*crash_size = 0;
1350	*crash_base = 0;
1351
1352	/* find crashkernel and use the last one if there are more */
1353	p = strstr(p, "crashkernel=");
1354	while (p) {
1355	ck_cmdline = p;
1356	p = strstr(p+1, "crashkernel=");
1357	}
1358
1359	if (!ck_cmdline)
1360	return -EINVAL;
1361
1362	ck_cmdline += 12; /* strlen("crashkernel=") */
1363
1364	/*
1365	* if the commandline contains a ':', then that's the extended
1366	* syntax -- if not, it must be the classic syntax
1367	*/
1368	first_colon = strchr(ck_cmdline, ':');
1369	first_space = strchr(ck_cmdline, ' ');
1370	if (first_colon && (!first_space \|\| first_colon < first_space))
1371	return parse_crashkernel_mem(ck_cmdline, system_ram,
1372	crash_size, crash_base);
1373	else
1374	return parse_crashkernel_simple(ck_cmdline, crash_size,
1375	crash_base);
1376
1377	return 0;
1378	}
1379
1380
1381
1382	void crash_save_vmcoreinfo(void)
1383	{
1384	u32 *buf;
1385
1386	if (!vmcoreinfo_size)
1387	return;
1388
1389	vmcoreinfo_append_str("CRASHTIME=%ld", get_seconds());
1390
1391	buf = (u32 *)vmcoreinfo_note;
1392
1393	buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
1394	vmcoreinfo_size);
1395
1396	final_note(buf);
1397	}
1398
1399	void vmcoreinfo_append_str(const char *fmt, ...)
1400	{
1401	va_list args;
1402	char buf[0x50];
1403	int r;
1404
1405	va_start(args, fmt);
1406	r = vsnprintf(buf, sizeof(buf), fmt, args);
1407	va_end(args);
1408
1409	if (r + vmcoreinfo_size > vmcoreinfo_max_size)
1410	r = vmcoreinfo_max_size - vmcoreinfo_size;
1411
1412	memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
1413
1414	vmcoreinfo_size += r;
1415	}
1416
1417	/*
1418	* provide an empty default implementation here -- architecture
1419	* code may override this
1420	*/
1421	void __attribute__ ((weak)) arch_crash_save_vmcoreinfo(void)
1422	{}
1423
1424	unsigned long __attribute__ ((weak)) paddr_vmcoreinfo_note(void)
1425	{
1426	return __pa((unsigned long)(char *)&vmcoreinfo_note);
1427	}
1428
1429	static int __init crash_save_vmcoreinfo_init(void)
1430	{
1431	VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
1432	VMCOREINFO_PAGESIZE(PAGE_SIZE);
1433
1434	VMCOREINFO_SYMBOL(init_uts_ns);
1435	VMCOREINFO_SYMBOL(node_online_map);
1436	VMCOREINFO_SYMBOL(swapper_pg_dir);
1437	VMCOREINFO_SYMBOL(_stext);
1438	VMCOREINFO_SYMBOL(vmlist);
1439
1440	#ifndef CONFIG_NEED_MULTIPLE_NODES
1441	VMCOREINFO_SYMBOL(mem_map);
1442	VMCOREINFO_SYMBOL(contig_page_data);
1443	#endif
1444	#ifdef CONFIG_SPARSEMEM
1445	VMCOREINFO_SYMBOL(mem_section);
1446	VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
1447	VMCOREINFO_STRUCT_SIZE(mem_section);
1448	VMCOREINFO_OFFSET(mem_section, section_mem_map);
1449	#endif
1450	VMCOREINFO_STRUCT_SIZE(page);
1451	VMCOREINFO_STRUCT_SIZE(pglist_data);
1452	VMCOREINFO_STRUCT_SIZE(zone);
1453	VMCOREINFO_STRUCT_SIZE(free_area);
1454	VMCOREINFO_STRUCT_SIZE(list_head);
1455	VMCOREINFO_SIZE(nodemask_t);
1456	VMCOREINFO_OFFSET(page, flags);
1457	VMCOREINFO_OFFSET(page, _count);
1458	VMCOREINFO_OFFSET(page, mapping);
1459	VMCOREINFO_OFFSET(page, lru);
1460	VMCOREINFO_OFFSET(pglist_data, node_zones);
1461	VMCOREINFO_OFFSET(pglist_data, nr_zones);
1462	#ifdef CONFIG_FLAT_NODE_MEM_MAP
1463	VMCOREINFO_OFFSET(pglist_data, node_mem_map);
1464	#endif
1465	VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
1466	VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
1467	VMCOREINFO_OFFSET(pglist_data, node_id);
1468	VMCOREINFO_OFFSET(zone, free_area);
1469	VMCOREINFO_OFFSET(zone, vm_stat);
1470	VMCOREINFO_OFFSET(zone, spanned_pages);
1471	VMCOREINFO_OFFSET(free_area, free_list);
1472	VMCOREINFO_OFFSET(list_head, next);
1473	VMCOREINFO_OFFSET(list_head, prev);
1474	VMCOREINFO_OFFSET(vm_struct, addr);
1475	VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
1476	log_buf_kexec_setup();
1477	VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
1478	VMCOREINFO_NUMBER(NR_FREE_PAGES);
1479	VMCOREINFO_NUMBER(PG_lru);
1480	VMCOREINFO_NUMBER(PG_private);
1481	VMCOREINFO_NUMBER(PG_swapcache);
1482
1483	arch_crash_save_vmcoreinfo();
1484
1485	return 0;
1486	}
1487
1488	module_init(crash_save_vmcoreinfo_init)
1489
1490	/*
1491	* Move into place and start executing a preloaded standalone
1492	* executable. If nothing was preloaded return an error.
1493	*/
1494	int kernel_kexec(void)
1495	{
1496	int error = 0;
1497
1498	if (!mutex_trylock(&kexec_mutex))
1499	return -EBUSY;
1500	if (!kexec_image) {
1501	error = -EINVAL;
1502	goto Unlock;
1503	}
1504
1505	#ifdef CONFIG_KEXEC_JUMP
1506	if (kexec_image->preserve_context) {
1507	mutex_lock(&pm_mutex);
1508	pm_prepare_console();
1509	error = freeze_processes();
1510	if (error) {
1511	error = -EBUSY;
1512	goto Restore_console;
1513	}
1514	suspend_console();
1515	error = dpm_suspend_start(PMSG_FREEZE);
1516	if (error)
1517	goto Resume_console;
1518	/* At this point, dpm_suspend_start() has been called,
1519	* but not dpm_suspend_noirq(). We must call
1520	* dpm_suspend_noirq() now. Otherwise, drivers for
1521	* some devices (e.g. interrupt controllers) become
1522	* desynchronized with the actual state of the
1523	* hardware at resume time, and evil weirdness ensues.
1524	*/
1525	error = dpm_suspend_noirq(PMSG_FREEZE);
1526	if (error)
1527	goto Resume_devices;
1528	error = disable_nonboot_cpus();
1529	if (error)
1530	goto Enable_cpus;
1531	local_irq_disable();
1532	/* Suspend system devices */
1533	error = sysdev_suspend(PMSG_FREEZE);
1534	if (error)
1535	goto Enable_irqs;
1536	} else
1537	#endif
1538	{
1539	kernel_restart_prepare(NULL);
1540	printk(KERN_EMERG "Starting new kernel\n");
1541	machine_shutdown();
1542	}
1543
1544	machine_kexec(kexec_image);
1545
1546	#ifdef CONFIG_KEXEC_JUMP
1547	if (kexec_image->preserve_context) {
1548	sysdev_resume();
1549	Enable_irqs:
1550	local_irq_enable();
1551	Enable_cpus:
1552	enable_nonboot_cpus();
1553	dpm_resume_noirq(PMSG_RESTORE);
1554	Resume_devices:
1555	dpm_resume_end(PMSG_RESTORE);
1556	Resume_console:
1557	resume_console();
1558	thaw_processes();
1559	Restore_console:
1560	pm_restore_console();
1561	mutex_unlock(&pm_mutex);
1562	}
1563	#endif
1564
1565	Unlock:
1566	mutex_unlock(&kexec_mutex);
1567	return error;
1568	}
1569

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