1 // SPDX-License-Identifier: GPL-2.0-only 1 // SPDX-License-Identifier: GPL-2.0-only
2 /* 2 /*
3 * kexec.c - kexec system call core code. 3 * kexec.c - kexec system call core code.
4 * Copyright (C) 2002-2004 Eric Biederman <eb 4 * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com>
5 */ 5 */
6 6
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8 8
9 #include <linux/btf.h> 9 #include <linux/btf.h>
10 #include <linux/capability.h> 10 #include <linux/capability.h>
11 #include <linux/mm.h> 11 #include <linux/mm.h>
12 #include <linux/file.h> 12 #include <linux/file.h>
13 #include <linux/slab.h> 13 #include <linux/slab.h>
14 #include <linux/fs.h> 14 #include <linux/fs.h>
15 #include <linux/kexec.h> 15 #include <linux/kexec.h>
16 #include <linux/mutex.h> 16 #include <linux/mutex.h>
17 #include <linux/list.h> 17 #include <linux/list.h>
18 #include <linux/highmem.h> 18 #include <linux/highmem.h>
19 #include <linux/syscalls.h> 19 #include <linux/syscalls.h>
20 #include <linux/reboot.h> 20 #include <linux/reboot.h>
21 #include <linux/ioport.h> 21 #include <linux/ioport.h>
22 #include <linux/hardirq.h> 22 #include <linux/hardirq.h>
23 #include <linux/elf.h> 23 #include <linux/elf.h>
24 #include <linux/elfcore.h> 24 #include <linux/elfcore.h>
25 #include <linux/utsname.h> 25 #include <linux/utsname.h>
26 #include <linux/numa.h> 26 #include <linux/numa.h>
27 #include <linux/suspend.h> 27 #include <linux/suspend.h>
28 #include <linux/device.h> 28 #include <linux/device.h>
29 #include <linux/freezer.h> 29 #include <linux/freezer.h>
30 #include <linux/panic_notifier.h> 30 #include <linux/panic_notifier.h>
31 #include <linux/pm.h> 31 #include <linux/pm.h>
32 #include <linux/cpu.h> 32 #include <linux/cpu.h>
33 #include <linux/uaccess.h> 33 #include <linux/uaccess.h>
34 #include <linux/io.h> 34 #include <linux/io.h>
35 #include <linux/console.h> 35 #include <linux/console.h>
36 #include <linux/vmalloc.h> 36 #include <linux/vmalloc.h>
37 #include <linux/swap.h> 37 #include <linux/swap.h>
38 #include <linux/syscore_ops.h> 38 #include <linux/syscore_ops.h>
39 #include <linux/compiler.h> 39 #include <linux/compiler.h>
40 #include <linux/hugetlb.h> 40 #include <linux/hugetlb.h>
41 #include <linux/objtool.h> 41 #include <linux/objtool.h>
42 #include <linux/kmsg_dump.h> 42 #include <linux/kmsg_dump.h>
43 43
44 #include <asm/page.h> 44 #include <asm/page.h>
45 #include <asm/sections.h> 45 #include <asm/sections.h>
46 46
47 #include <crypto/hash.h> 47 #include <crypto/hash.h>
48 #include "kexec_internal.h" 48 #include "kexec_internal.h"
49 49
50 atomic_t __kexec_lock = ATOMIC_INIT(0); 50 atomic_t __kexec_lock = ATOMIC_INIT(0);
51 51
52 /* Flag to indicate we are going to kexec a ne 52 /* Flag to indicate we are going to kexec a new kernel */
53 bool kexec_in_progress = false; 53 bool kexec_in_progress = false;
54 54
55 bool kexec_file_dbg_print; 55 bool kexec_file_dbg_print;
56 56
57 /* 57 /*
58 * When kexec transitions to the new kernel th 58 * When kexec transitions to the new kernel there is a one-to-one
59 * mapping between physical and virtual addres 59 * mapping between physical and virtual addresses. On processors
60 * where you can disable the MMU this is trivi 60 * where you can disable the MMU this is trivial, and easy. For
61 * others it is still a simple predictable pag 61 * others it is still a simple predictable page table to setup.
62 * 62 *
63 * In that environment kexec copies the new ke 63 * In that environment kexec copies the new kernel to its final
64 * resting place. This means I can only suppo 64 * resting place. This means I can only support memory whose
65 * physical address can fit in an unsigned lon 65 * physical address can fit in an unsigned long. In particular
66 * addresses where (pfn << PAGE_SHIFT) > ULONG 66 * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled.
67 * If the assembly stub has more restrictive r 67 * If the assembly stub has more restrictive requirements
68 * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_ME 68 * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be
69 * defined more restrictively in <asm/kexec.h> 69 * defined more restrictively in <asm/kexec.h>.
70 * 70 *
71 * The code for the transition from the curren 71 * The code for the transition from the current kernel to the
72 * new kernel is placed in the control_code_bu 72 * new kernel is placed in the control_code_buffer, whose size
73 * is given by KEXEC_CONTROL_PAGE_SIZE. In th 73 * is given by KEXEC_CONTROL_PAGE_SIZE. In the best case only a single
74 * page of memory is necessary, but some archi 74 * page of memory is necessary, but some architectures require more.
75 * Because this memory must be identity mapped 75 * Because this memory must be identity mapped in the transition from
76 * virtual to physical addresses it must live 76 * virtual to physical addresses it must live in the range
77 * 0 - TASK_SIZE, as only the user space mappi 77 * 0 - TASK_SIZE, as only the user space mappings are arbitrarily
78 * modifiable. 78 * modifiable.
79 * 79 *
80 * The assembly stub in the control code buffe 80 * The assembly stub in the control code buffer is passed a linked list
81 * of descriptor pages detailing the source pa 81 * of descriptor pages detailing the source pages of the new kernel,
82 * and the destination addresses of those sour 82 * and the destination addresses of those source pages. As this data
83 * structure is not used in the context of the 83 * structure is not used in the context of the current OS, it must
84 * be self-contained. 84 * be self-contained.
85 * 85 *
86 * The code has been made to work with highmem 86 * The code has been made to work with highmem pages and will use a
87 * destination page in its final resting place 87 * destination page in its final resting place (if it happens
88 * to allocate it). The end product of this i 88 * to allocate it). The end product of this is that most of the
89 * physical address space, and most of RAM can 89 * physical address space, and most of RAM can be used.
90 * 90 *
91 * Future directions include: 91 * Future directions include:
92 * - allocating a page table with the control 92 * - allocating a page table with the control code buffer identity
93 * mapped, to simplify machine_kexec and ma 93 * mapped, to simplify machine_kexec and make kexec_on_panic more
94 * reliable. 94 * reliable.
95 */ 95 */
96 96
97 /* 97 /*
98 * KIMAGE_NO_DEST is an impossible destination 98 * KIMAGE_NO_DEST is an impossible destination address..., for
99 * allocating pages whose destination address 99 * allocating pages whose destination address we do not care about.
100 */ 100 */
101 #define KIMAGE_NO_DEST (-1UL) 101 #define KIMAGE_NO_DEST (-1UL)
102 #define PAGE_COUNT(x) (((x) + PAGE_SIZE - 1) > 102 #define PAGE_COUNT(x) (((x) + PAGE_SIZE - 1) >> PAGE_SHIFT)
103 103
104 static struct page *kimage_alloc_page(struct k 104 static struct page *kimage_alloc_page(struct kimage *image,
105 gfp_t g 105 gfp_t gfp_mask,
106 unsigne 106 unsigned long dest);
107 107
108 int sanity_check_segment_list(struct kimage *i 108 int sanity_check_segment_list(struct kimage *image)
109 { 109 {
110 int i; 110 int i;
111 unsigned long nr_segments = image->nr_ 111 unsigned long nr_segments = image->nr_segments;
112 unsigned long total_pages = 0; 112 unsigned long total_pages = 0;
113 unsigned long nr_pages = totalram_page 113 unsigned long nr_pages = totalram_pages();
114 114
115 /* 115 /*
116 * Verify we have good destination add 116 * Verify we have good destination addresses. The caller is
117 * responsible for making certain we d 117 * responsible for making certain we don't attempt to load
118 * the new image into invalid or reser 118 * the new image into invalid or reserved areas of RAM. This
119 * just verifies it is an address we c 119 * just verifies it is an address we can use.
120 * 120 *
121 * Since the kernel does everything in 121 * Since the kernel does everything in page size chunks ensure
122 * the destination addresses are page 122 * the destination addresses are page aligned. Too many
123 * special cases crop of when we don't 123 * special cases crop of when we don't do this. The most
124 * insidious is getting overlapping de 124 * insidious is getting overlapping destination addresses
125 * simply because addresses are change 125 * simply because addresses are changed to page size
126 * granularity. 126 * granularity.
127 */ 127 */
128 for (i = 0; i < nr_segments; i++) { 128 for (i = 0; i < nr_segments; i++) {
129 unsigned long mstart, mend; 129 unsigned long mstart, mend;
130 130
131 mstart = image->segment[i].mem 131 mstart = image->segment[i].mem;
132 mend = mstart + image->segme 132 mend = mstart + image->segment[i].memsz;
133 if (mstart > mend) 133 if (mstart > mend)
134 return -EADDRNOTAVAIL; 134 return -EADDRNOTAVAIL;
135 if ((mstart & ~PAGE_MASK) || ( 135 if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK))
136 return -EADDRNOTAVAIL; 136 return -EADDRNOTAVAIL;
137 if (mend >= KEXEC_DESTINATION_ 137 if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT)
138 return -EADDRNOTAVAIL; 138 return -EADDRNOTAVAIL;
139 } 139 }
140 140
141 /* Verify our destination addresses do 141 /* Verify our destination addresses do not overlap.
142 * If we alloed overlapping destinatio 142 * If we alloed overlapping destination addresses
143 * through very weird things can happe 143 * through very weird things can happen with no
144 * easy explanation as one segment sto 144 * easy explanation as one segment stops on another.
145 */ 145 */
146 for (i = 0; i < nr_segments; i++) { 146 for (i = 0; i < nr_segments; i++) {
147 unsigned long mstart, mend; 147 unsigned long mstart, mend;
148 unsigned long j; 148 unsigned long j;
149 149
150 mstart = image->segment[i].mem 150 mstart = image->segment[i].mem;
151 mend = mstart + image->segme 151 mend = mstart + image->segment[i].memsz;
152 for (j = 0; j < i; j++) { 152 for (j = 0; j < i; j++) {
153 unsigned long pstart, 153 unsigned long pstart, pend;
154 154
155 pstart = image->segmen 155 pstart = image->segment[j].mem;
156 pend = pstart + imag 156 pend = pstart + image->segment[j].memsz;
157 /* Do the segments ove 157 /* Do the segments overlap ? */
158 if ((mend > pstart) && 158 if ((mend > pstart) && (mstart < pend))
159 return -EINVAL 159 return -EINVAL;
160 } 160 }
161 } 161 }
162 162
163 /* Ensure our buffer sizes are strictl 163 /* Ensure our buffer sizes are strictly less than
164 * our memory sizes. This should alwa 164 * our memory sizes. This should always be the case,
165 * and it is easier to check up front 165 * and it is easier to check up front than to be surprised
166 * later on. 166 * later on.
167 */ 167 */
168 for (i = 0; i < nr_segments; i++) { 168 for (i = 0; i < nr_segments; i++) {
169 if (image->segment[i].bufsz > 169 if (image->segment[i].bufsz > image->segment[i].memsz)
170 return -EINVAL; 170 return -EINVAL;
171 } 171 }
172 172
173 /* 173 /*
174 * Verify that no more than half of me 174 * Verify that no more than half of memory will be consumed. If the
175 * request from userspace is too large 175 * request from userspace is too large, a large amount of time will be
176 * wasted allocating pages, which can 176 * wasted allocating pages, which can cause a soft lockup.
177 */ 177 */
178 for (i = 0; i < nr_segments; i++) { 178 for (i = 0; i < nr_segments; i++) {
179 if (PAGE_COUNT(image->segment[ 179 if (PAGE_COUNT(image->segment[i].memsz) > nr_pages / 2)
180 return -EINVAL; 180 return -EINVAL;
181 181
182 total_pages += PAGE_COUNT(imag 182 total_pages += PAGE_COUNT(image->segment[i].memsz);
183 } 183 }
184 184
185 if (total_pages > nr_pages / 2) 185 if (total_pages > nr_pages / 2)
186 return -EINVAL; 186 return -EINVAL;
187 187
188 #ifdef CONFIG_CRASH_DUMP 188 #ifdef CONFIG_CRASH_DUMP
189 /* 189 /*
190 * Verify we have good destination add 190 * Verify we have good destination addresses. Normally
191 * the caller is responsible for makin 191 * the caller is responsible for making certain we don't
192 * attempt to load the new image into 192 * attempt to load the new image into invalid or reserved
193 * areas of RAM. But crash kernels ar 193 * areas of RAM. But crash kernels are preloaded into a
194 * reserved area of ram. We must ensu 194 * reserved area of ram. We must ensure the addresses
195 * are in the reserved area otherwise 195 * are in the reserved area otherwise preloading the
196 * kernel could corrupt things. 196 * kernel could corrupt things.
197 */ 197 */
198 198
199 if (image->type == KEXEC_TYPE_CRASH) { 199 if (image->type == KEXEC_TYPE_CRASH) {
200 for (i = 0; i < nr_segments; i 200 for (i = 0; i < nr_segments; i++) {
201 unsigned long mstart, 201 unsigned long mstart, mend;
202 202
203 mstart = image->segmen 203 mstart = image->segment[i].mem;
204 mend = mstart + image- 204 mend = mstart + image->segment[i].memsz - 1;
205 /* Ensure we are withi 205 /* Ensure we are within the crash kernel limits */
206 if ((mstart < phys_to_ 206 if ((mstart < phys_to_boot_phys(crashk_res.start)) ||
207 (mend > phys_to_bo 207 (mend > phys_to_boot_phys(crashk_res.end)))
208 return -EADDRN 208 return -EADDRNOTAVAIL;
209 } 209 }
210 } 210 }
211 #endif 211 #endif
212 212
213 return 0; 213 return 0;
214 } 214 }
215 215
216 struct kimage *do_kimage_alloc_init(void) 216 struct kimage *do_kimage_alloc_init(void)
217 { 217 {
218 struct kimage *image; 218 struct kimage *image;
219 219
220 /* Allocate a controlling structure */ 220 /* Allocate a controlling structure */
221 image = kzalloc(sizeof(*image), GFP_KE 221 image = kzalloc(sizeof(*image), GFP_KERNEL);
222 if (!image) 222 if (!image)
223 return NULL; 223 return NULL;
224 224
225 image->head = 0; 225 image->head = 0;
226 image->entry = &image->head; 226 image->entry = &image->head;
227 image->last_entry = &image->head; 227 image->last_entry = &image->head;
228 image->control_page = ~0; /* By defaul 228 image->control_page = ~0; /* By default this does not apply */
229 image->type = KEXEC_TYPE_DEFAULT; 229 image->type = KEXEC_TYPE_DEFAULT;
230 230
231 /* Initialize the list of control page 231 /* Initialize the list of control pages */
232 INIT_LIST_HEAD(&image->control_pages); 232 INIT_LIST_HEAD(&image->control_pages);
233 233
234 /* Initialize the list of destination 234 /* Initialize the list of destination pages */
235 INIT_LIST_HEAD(&image->dest_pages); 235 INIT_LIST_HEAD(&image->dest_pages);
236 236
237 /* Initialize the list of unusable pag 237 /* Initialize the list of unusable pages */
238 INIT_LIST_HEAD(&image->unusable_pages) 238 INIT_LIST_HEAD(&image->unusable_pages);
239 239
240 #ifdef CONFIG_CRASH_HOTPLUG 240 #ifdef CONFIG_CRASH_HOTPLUG
241 image->hp_action = KEXEC_CRASH_HP_NONE 241 image->hp_action = KEXEC_CRASH_HP_NONE;
242 image->elfcorehdr_index = -1; 242 image->elfcorehdr_index = -1;
243 image->elfcorehdr_updated = false; 243 image->elfcorehdr_updated = false;
244 #endif 244 #endif
245 245
246 return image; 246 return image;
247 } 247 }
248 248
249 int kimage_is_destination_range(struct kimage 249 int kimage_is_destination_range(struct kimage *image,
250 unsign 250 unsigned long start,
251 unsign 251 unsigned long end)
252 { 252 {
253 unsigned long i; 253 unsigned long i;
254 254
255 for (i = 0; i < image->nr_segments; i+ 255 for (i = 0; i < image->nr_segments; i++) {
256 unsigned long mstart, mend; 256 unsigned long mstart, mend;
257 257
258 mstart = image->segment[i].mem 258 mstart = image->segment[i].mem;
259 mend = mstart + image->segment 259 mend = mstart + image->segment[i].memsz - 1;
260 if ((end >= mstart) && (start 260 if ((end >= mstart) && (start <= mend))
261 return 1; 261 return 1;
262 } 262 }
263 263
264 return 0; 264 return 0;
265 } 265 }
266 266
267 static struct page *kimage_alloc_pages(gfp_t g 267 static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order)
268 { 268 {
269 struct page *pages; 269 struct page *pages;
270 270
271 if (fatal_signal_pending(current)) 271 if (fatal_signal_pending(current))
272 return NULL; 272 return NULL;
273 pages = alloc_pages(gfp_mask & ~__GFP_ 273 pages = alloc_pages(gfp_mask & ~__GFP_ZERO, order);
274 if (pages) { 274 if (pages) {
275 unsigned int count, i; 275 unsigned int count, i;
276 276
277 pages->mapping = NULL; 277 pages->mapping = NULL;
278 set_page_private(pages, order) 278 set_page_private(pages, order);
279 count = 1 << order; 279 count = 1 << order;
280 for (i = 0; i < count; i++) 280 for (i = 0; i < count; i++)
281 SetPageReserved(pages 281 SetPageReserved(pages + i);
282 282
283 arch_kexec_post_alloc_pages(pa 283 arch_kexec_post_alloc_pages(page_address(pages), count,
284 gf 284 gfp_mask);
285 285
286 if (gfp_mask & __GFP_ZERO) 286 if (gfp_mask & __GFP_ZERO)
287 for (i = 0; i < count; 287 for (i = 0; i < count; i++)
288 clear_highpage 288 clear_highpage(pages + i);
289 } 289 }
290 290
291 return pages; 291 return pages;
292 } 292 }
293 293
294 static void kimage_free_pages(struct page *pag 294 static void kimage_free_pages(struct page *page)
295 { 295 {
296 unsigned int order, count, i; 296 unsigned int order, count, i;
297 297
298 order = page_private(page); 298 order = page_private(page);
299 count = 1 << order; 299 count = 1 << order;
300 300
301 arch_kexec_pre_free_pages(page_address 301 arch_kexec_pre_free_pages(page_address(page), count);
302 302
303 for (i = 0; i < count; i++) 303 for (i = 0; i < count; i++)
304 ClearPageReserved(page + i); 304 ClearPageReserved(page + i);
305 __free_pages(page, order); 305 __free_pages(page, order);
306 } 306 }
307 307
308 void kimage_free_page_list(struct list_head *l 308 void kimage_free_page_list(struct list_head *list)
309 { 309 {
310 struct page *page, *next; 310 struct page *page, *next;
311 311
312 list_for_each_entry_safe(page, next, l 312 list_for_each_entry_safe(page, next, list, lru) {
313 list_del(&page->lru); 313 list_del(&page->lru);
314 kimage_free_pages(page); 314 kimage_free_pages(page);
315 } 315 }
316 } 316 }
317 317
318 static struct page *kimage_alloc_normal_contro 318 static struct page *kimage_alloc_normal_control_pages(struct kimage *image,
319 319 unsigned int order)
320 { 320 {
321 /* Control pages are special, they are 321 /* Control pages are special, they are the intermediaries
322 * that are needed while we copy the r 322 * that are needed while we copy the rest of the pages
323 * to their final resting place. As s 323 * to their final resting place. As such they must
324 * not conflict with either the destin 324 * not conflict with either the destination addresses
325 * or memory the kernel is already usi 325 * or memory the kernel is already using.
326 * 326 *
327 * The only case where we really need 327 * The only case where we really need more than one of
328 * these are for architectures where w 328 * these are for architectures where we cannot disable
329 * the MMU and must instead generate a 329 * the MMU and must instead generate an identity mapped
330 * page table for all of the memory. 330 * page table for all of the memory.
331 * 331 *
332 * At worst this runs in O(N) of the i 332 * At worst this runs in O(N) of the image size.
333 */ 333 */
334 struct list_head extra_pages; 334 struct list_head extra_pages;
335 struct page *pages; 335 struct page *pages;
336 unsigned int count; 336 unsigned int count;
337 337
338 count = 1 << order; 338 count = 1 << order;
339 INIT_LIST_HEAD(&extra_pages); 339 INIT_LIST_HEAD(&extra_pages);
340 340
341 /* Loop while I can allocate a page an 341 /* Loop while I can allocate a page and the page allocated
342 * is a destination page. 342 * is a destination page.
343 */ 343 */
344 do { 344 do {
345 unsigned long pfn, epfn, addr, 345 unsigned long pfn, epfn, addr, eaddr;
346 346
347 pages = kimage_alloc_pages(KEX 347 pages = kimage_alloc_pages(KEXEC_CONTROL_MEMORY_GFP, order);
348 if (!pages) 348 if (!pages)
349 break; 349 break;
350 pfn = page_to_boot_pfn(pages 350 pfn = page_to_boot_pfn(pages);
351 epfn = pfn + count; 351 epfn = pfn + count;
352 addr = pfn << PAGE_SHIFT; 352 addr = pfn << PAGE_SHIFT;
353 eaddr = (epfn << PAGE_SHIFT) - 353 eaddr = (epfn << PAGE_SHIFT) - 1;
354 if ((epfn >= (KEXEC_CONTROL_ME 354 if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) ||
355 kimage_is_destin 355 kimage_is_destination_range(image, addr, eaddr)) {
356 list_add(&pages->lru, 356 list_add(&pages->lru, &extra_pages);
357 pages = NULL; 357 pages = NULL;
358 } 358 }
359 } while (!pages); 359 } while (!pages);
360 360
361 if (pages) { 361 if (pages) {
362 /* Remember the allocated page 362 /* Remember the allocated page... */
363 list_add(&pages->lru, &image-> 363 list_add(&pages->lru, &image->control_pages);
364 364
365 /* Because the page is already 365 /* Because the page is already in it's destination
366 * location we will never allo 366 * location we will never allocate another page at
367 * that address. Therefore ki 367 * that address. Therefore kimage_alloc_pages
368 * will not return it (again) 368 * will not return it (again) and we don't need
369 * to give it an entry in imag 369 * to give it an entry in image->segment[].
370 */ 370 */
371 } 371 }
372 /* Deal with the destination pages I h 372 /* Deal with the destination pages I have inadvertently allocated.
373 * 373 *
374 * Ideally I would convert multi-page 374 * Ideally I would convert multi-page allocations into single
375 * page allocations, and add everythin 375 * page allocations, and add everything to image->dest_pages.
376 * 376 *
377 * For now it is simpler to just free 377 * For now it is simpler to just free the pages.
378 */ 378 */
379 kimage_free_page_list(&extra_pages); 379 kimage_free_page_list(&extra_pages);
380 380
381 return pages; 381 return pages;
382 } 382 }
383 383
384 #ifdef CONFIG_CRASH_DUMP 384 #ifdef CONFIG_CRASH_DUMP
385 static struct page *kimage_alloc_crash_control 385 static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
386 386 unsigned int order)
387 { 387 {
388 /* Control pages are special, they are 388 /* Control pages are special, they are the intermediaries
389 * that are needed while we copy the r 389 * that are needed while we copy the rest of the pages
390 * to their final resting place. As s 390 * to their final resting place. As such they must
391 * not conflict with either the destin 391 * not conflict with either the destination addresses
392 * or memory the kernel is already usi 392 * or memory the kernel is already using.
393 * 393 *
394 * Control pages are also the only pag 394 * Control pages are also the only pags we must allocate
395 * when loading a crash kernel. All o 395 * when loading a crash kernel. All of the other pages
396 * are specified by the segments and w 396 * are specified by the segments and we just memcpy
397 * into them directly. 397 * into them directly.
398 * 398 *
399 * The only case where we really need 399 * The only case where we really need more than one of
400 * these are for architectures where w 400 * these are for architectures where we cannot disable
401 * the MMU and must instead generate a 401 * the MMU and must instead generate an identity mapped
402 * page table for all of the memory. 402 * page table for all of the memory.
403 * 403 *
404 * Given the low demand this implement 404 * Given the low demand this implements a very simple
405 * allocator that finds the first hole 405 * allocator that finds the first hole of the appropriate
406 * size in the reserved memory region, 406 * size in the reserved memory region, and allocates all
407 * of the memory up to and including t 407 * of the memory up to and including the hole.
408 */ 408 */
409 unsigned long hole_start, hole_end, si 409 unsigned long hole_start, hole_end, size;
410 struct page *pages; 410 struct page *pages;
411 411
412 pages = NULL; 412 pages = NULL;
413 size = (1 << order) << PAGE_SHIFT; 413 size = (1 << order) << PAGE_SHIFT;
414 hole_start = ALIGN(image->control_page 414 hole_start = ALIGN(image->control_page, size);
415 hole_end = hole_start + size - 1; 415 hole_end = hole_start + size - 1;
416 while (hole_end <= crashk_res.end) { 416 while (hole_end <= crashk_res.end) {
417 unsigned long i; 417 unsigned long i;
418 418
419 cond_resched(); 419 cond_resched();
420 420
421 if (hole_end > KEXEC_CRASH_CON 421 if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT)
422 break; 422 break;
423 /* See if I overlap any of the 423 /* See if I overlap any of the segments */
424 for (i = 0; i < image->nr_segm 424 for (i = 0; i < image->nr_segments; i++) {
425 unsigned long mstart, 425 unsigned long mstart, mend;
426 426
427 mstart = image->segmen 427 mstart = image->segment[i].mem;
428 mend = mstart + imag 428 mend = mstart + image->segment[i].memsz - 1;
429 if ((hole_end >= mstar 429 if ((hole_end >= mstart) && (hole_start <= mend)) {
430 /* Advance the 430 /* Advance the hole to the end of the segment */
431 hole_start = A 431 hole_start = ALIGN(mend, size);
432 hole_end = h 432 hole_end = hole_start + size - 1;
433 break; 433 break;
434 } 434 }
435 } 435 }
436 /* If I don't overlap any segm 436 /* If I don't overlap any segments I have found my hole! */
437 if (i == image->nr_segments) { 437 if (i == image->nr_segments) {
438 pages = pfn_to_page(ho 438 pages = pfn_to_page(hole_start >> PAGE_SHIFT);
439 image->control_page = 439 image->control_page = hole_end + 1;
440 break; 440 break;
441 } 441 }
442 } 442 }
443 443
444 /* Ensure that these pages are decrypt 444 /* Ensure that these pages are decrypted if SME is enabled. */
445 if (pages) 445 if (pages)
446 arch_kexec_post_alloc_pages(pa 446 arch_kexec_post_alloc_pages(page_address(pages), 1 << order, 0);
447 447
448 return pages; 448 return pages;
449 } 449 }
450 #endif 450 #endif
451 451
452 452
453 struct page *kimage_alloc_control_pages(struct 453 struct page *kimage_alloc_control_pages(struct kimage *image,
454 unsig 454 unsigned int order)
455 { 455 {
456 struct page *pages = NULL; 456 struct page *pages = NULL;
457 457
458 switch (image->type) { 458 switch (image->type) {
459 case KEXEC_TYPE_DEFAULT: 459 case KEXEC_TYPE_DEFAULT:
460 pages = kimage_alloc_normal_co 460 pages = kimage_alloc_normal_control_pages(image, order);
461 break; 461 break;
462 #ifdef CONFIG_CRASH_DUMP 462 #ifdef CONFIG_CRASH_DUMP
463 case KEXEC_TYPE_CRASH: 463 case KEXEC_TYPE_CRASH:
464 pages = kimage_alloc_crash_con 464 pages = kimage_alloc_crash_control_pages(image, order);
465 break; 465 break;
466 #endif 466 #endif
467 } 467 }
468 468
469 return pages; 469 return pages;
470 } 470 }
471 471
472 static int kimage_add_entry(struct kimage *ima 472 static int kimage_add_entry(struct kimage *image, kimage_entry_t entry)
473 { 473 {
474 if (*image->entry != 0) 474 if (*image->entry != 0)
475 image->entry++; 475 image->entry++;
476 476
477 if (image->entry == image->last_entry) 477 if (image->entry == image->last_entry) {
478 kimage_entry_t *ind_page; 478 kimage_entry_t *ind_page;
479 struct page *page; 479 struct page *page;
480 480
481 page = kimage_alloc_page(image 481 page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST);
482 if (!page) 482 if (!page)
483 return -ENOMEM; 483 return -ENOMEM;
484 484
485 ind_page = page_address(page); 485 ind_page = page_address(page);
486 *image->entry = virt_to_boot_p 486 *image->entry = virt_to_boot_phys(ind_page) | IND_INDIRECTION;
487 image->entry = ind_page; 487 image->entry = ind_page;
488 image->last_entry = ind_page + 488 image->last_entry = ind_page +
489 ((PAGE_S 489 ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1);
490 } 490 }
491 *image->entry = entry; 491 *image->entry = entry;
492 image->entry++; 492 image->entry++;
493 *image->entry = 0; 493 *image->entry = 0;
494 494
495 return 0; 495 return 0;
496 } 496 }
497 497
498 static int kimage_set_destination(struct kimag 498 static int kimage_set_destination(struct kimage *image,
499 unsigned lo 499 unsigned long destination)
500 { 500 {
501 destination &= PAGE_MASK; 501 destination &= PAGE_MASK;
502 502
503 return kimage_add_entry(image, destina 503 return kimage_add_entry(image, destination | IND_DESTINATION);
504 } 504 }
505 505
506 506
507 static int kimage_add_page(struct kimage *imag 507 static int kimage_add_page(struct kimage *image, unsigned long page)
508 { 508 {
509 page &= PAGE_MASK; 509 page &= PAGE_MASK;
510 510
511 return kimage_add_entry(image, page | 511 return kimage_add_entry(image, page | IND_SOURCE);
512 } 512 }
513 513
514 514
515 static void kimage_free_extra_pages(struct kim 515 static void kimage_free_extra_pages(struct kimage *image)
516 { 516 {
517 /* Walk through and free any extra des 517 /* Walk through and free any extra destination pages I may have */
518 kimage_free_page_list(&image->dest_pag 518 kimage_free_page_list(&image->dest_pages);
519 519
520 /* Walk through and free any unusable 520 /* Walk through and free any unusable pages I have cached */
521 kimage_free_page_list(&image->unusable 521 kimage_free_page_list(&image->unusable_pages);
522 522
523 } 523 }
524 524
525 void kimage_terminate(struct kimage *image) 525 void kimage_terminate(struct kimage *image)
526 { 526 {
527 if (*image->entry != 0) 527 if (*image->entry != 0)
528 image->entry++; 528 image->entry++;
529 529
530 *image->entry = IND_DONE; 530 *image->entry = IND_DONE;
531 } 531 }
532 532
533 #define for_each_kimage_entry(image, ptr, entr 533 #define for_each_kimage_entry(image, ptr, entry) \
534 for (ptr = &image->head; (entry = *ptr 534 for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \
535 ptr = (entry & IND_INDIRECTION 535 ptr = (entry & IND_INDIRECTION) ? \
536 boot_phys_to_virt((ent 536 boot_phys_to_virt((entry & PAGE_MASK)) : ptr + 1)
537 537
538 static void kimage_free_entry(kimage_entry_t e 538 static void kimage_free_entry(kimage_entry_t entry)
539 { 539 {
540 struct page *page; 540 struct page *page;
541 541
542 page = boot_pfn_to_page(entry >> PAGE_ 542 page = boot_pfn_to_page(entry >> PAGE_SHIFT);
543 kimage_free_pages(page); 543 kimage_free_pages(page);
544 } 544 }
545 545
546 void kimage_free(struct kimage *image) 546 void kimage_free(struct kimage *image)
547 { 547 {
548 kimage_entry_t *ptr, entry; 548 kimage_entry_t *ptr, entry;
549 kimage_entry_t ind = 0; 549 kimage_entry_t ind = 0;
550 550
551 if (!image) 551 if (!image)
552 return; 552 return;
553 553
554 #ifdef CONFIG_CRASH_DUMP 554 #ifdef CONFIG_CRASH_DUMP
555 if (image->vmcoreinfo_data_copy) { 555 if (image->vmcoreinfo_data_copy) {
556 crash_update_vmcoreinfo_safeco 556 crash_update_vmcoreinfo_safecopy(NULL);
557 vunmap(image->vmcoreinfo_data_ 557 vunmap(image->vmcoreinfo_data_copy);
558 } 558 }
559 #endif 559 #endif
560 560
561 kimage_free_extra_pages(image); 561 kimage_free_extra_pages(image);
562 for_each_kimage_entry(image, ptr, entr 562 for_each_kimage_entry(image, ptr, entry) {
563 if (entry & IND_INDIRECTION) { 563 if (entry & IND_INDIRECTION) {
564 /* Free the previous i 564 /* Free the previous indirection page */
565 if (ind & IND_INDIRECT 565 if (ind & IND_INDIRECTION)
566 kimage_free_en 566 kimage_free_entry(ind);
567 /* Save this indirecti 567 /* Save this indirection page until we are
568 * done with it. 568 * done with it.
569 */ 569 */
570 ind = entry; 570 ind = entry;
571 } else if (entry & IND_SOURCE) 571 } else if (entry & IND_SOURCE)
572 kimage_free_entry(entr 572 kimage_free_entry(entry);
573 } 573 }
574 /* Free the final indirection page */ 574 /* Free the final indirection page */
575 if (ind & IND_INDIRECTION) 575 if (ind & IND_INDIRECTION)
576 kimage_free_entry(ind); 576 kimage_free_entry(ind);
577 577
578 /* Handle any machine specific cleanup 578 /* Handle any machine specific cleanup */
579 machine_kexec_cleanup(image); 579 machine_kexec_cleanup(image);
580 580
581 /* Free the kexec control pages... */ 581 /* Free the kexec control pages... */
582 kimage_free_page_list(&image->control_ 582 kimage_free_page_list(&image->control_pages);
583 583
584 /* 584 /*
585 * Free up any temporary buffers alloc 585 * Free up any temporary buffers allocated. This might hit if
586 * error occurred much later after buf 586 * error occurred much later after buffer allocation.
587 */ 587 */
588 if (image->file_mode) 588 if (image->file_mode)
589 kimage_file_post_load_cleanup( 589 kimage_file_post_load_cleanup(image);
590 590
591 kfree(image); 591 kfree(image);
592 } 592 }
593 593
594 static kimage_entry_t *kimage_dst_used(struct 594 static kimage_entry_t *kimage_dst_used(struct kimage *image,
595 unsign 595 unsigned long page)
596 { 596 {
597 kimage_entry_t *ptr, entry; 597 kimage_entry_t *ptr, entry;
598 unsigned long destination = 0; 598 unsigned long destination = 0;
599 599
600 for_each_kimage_entry(image, ptr, entr 600 for_each_kimage_entry(image, ptr, entry) {
601 if (entry & IND_DESTINATION) 601 if (entry & IND_DESTINATION)
602 destination = entry & 602 destination = entry & PAGE_MASK;
603 else if (entry & IND_SOURCE) { 603 else if (entry & IND_SOURCE) {
604 if (page == destinatio 604 if (page == destination)
605 return ptr; 605 return ptr;
606 destination += PAGE_SI 606 destination += PAGE_SIZE;
607 } 607 }
608 } 608 }
609 609
610 return NULL; 610 return NULL;
611 } 611 }
612 612
613 static struct page *kimage_alloc_page(struct k 613 static struct page *kimage_alloc_page(struct kimage *image,
614 gfp_t 614 gfp_t gfp_mask,
615 unsign 615 unsigned long destination)
616 { 616 {
617 /* 617 /*
618 * Here we implement safeguards to ens 618 * Here we implement safeguards to ensure that a source page
619 * is not copied to its destination pa 619 * is not copied to its destination page before the data on
620 * the destination page is no longer u 620 * the destination page is no longer useful.
621 * 621 *
622 * To do this we maintain the invarian 622 * To do this we maintain the invariant that a source page is
623 * either its own destination page, or 623 * either its own destination page, or it is not a
624 * destination page at all. 624 * destination page at all.
625 * 625 *
626 * That is slightly stronger than requ 626 * That is slightly stronger than required, but the proof
627 * that no problems will not occur is 627 * that no problems will not occur is trivial, and the
628 * implementation is simply to verify. 628 * implementation is simply to verify.
629 * 629 *
630 * When allocating all pages normally 630 * When allocating all pages normally this algorithm will run
631 * in O(N) time, but in the worst case 631 * in O(N) time, but in the worst case it will run in O(N^2)
632 * time. If the runtime is a problem 632 * time. If the runtime is a problem the data structures can
633 * be fixed. 633 * be fixed.
634 */ 634 */
635 struct page *page; 635 struct page *page;
636 unsigned long addr; 636 unsigned long addr;
637 637
638 /* 638 /*
639 * Walk through the list of destinatio 639 * Walk through the list of destination pages, and see if I
640 * have a match. 640 * have a match.
641 */ 641 */
642 list_for_each_entry(page, &image->dest 642 list_for_each_entry(page, &image->dest_pages, lru) {
643 addr = page_to_boot_pfn(page) 643 addr = page_to_boot_pfn(page) << PAGE_SHIFT;
644 if (addr == destination) { 644 if (addr == destination) {
645 list_del(&page->lru); 645 list_del(&page->lru);
646 return page; 646 return page;
647 } 647 }
648 } 648 }
649 page = NULL; 649 page = NULL;
650 while (1) { 650 while (1) {
651 kimage_entry_t *old; 651 kimage_entry_t *old;
652 652
653 /* Allocate a page, if we run 653 /* Allocate a page, if we run out of memory give up */
654 page = kimage_alloc_pages(gfp_ 654 page = kimage_alloc_pages(gfp_mask, 0);
655 if (!page) 655 if (!page)
656 return NULL; 656 return NULL;
657 /* If the page cannot be used 657 /* If the page cannot be used file it away */
658 if (page_to_boot_pfn(page) > 658 if (page_to_boot_pfn(page) >
659 (KEXEC_SOURCE_ 659 (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
660 list_add(&page->lru, & 660 list_add(&page->lru, &image->unusable_pages);
661 continue; 661 continue;
662 } 662 }
663 addr = page_to_boot_pfn(page) 663 addr = page_to_boot_pfn(page) << PAGE_SHIFT;
664 664
665 /* If it is the destination pa 665 /* If it is the destination page we want use it */
666 if (addr == destination) 666 if (addr == destination)
667 break; 667 break;
668 668
669 /* If the page is not a destin 669 /* If the page is not a destination page use it */
670 if (!kimage_is_destination_ran 670 if (!kimage_is_destination_range(image, addr,
671 671 addr + PAGE_SIZE - 1))
672 break; 672 break;
673 673
674 /* 674 /*
675 * I know that the page is som 675 * I know that the page is someones destination page.
676 * See if there is already a s 676 * See if there is already a source page for this
677 * destination page. And if s 677 * destination page. And if so swap the source pages.
678 */ 678 */
679 old = kimage_dst_used(image, a 679 old = kimage_dst_used(image, addr);
680 if (old) { 680 if (old) {
681 /* If so move it */ 681 /* If so move it */
682 unsigned long old_addr 682 unsigned long old_addr;
683 struct page *old_page; 683 struct page *old_page;
684 684
685 old_addr = *old & PAGE 685 old_addr = *old & PAGE_MASK;
686 old_page = boot_pfn_to 686 old_page = boot_pfn_to_page(old_addr >> PAGE_SHIFT);
687 copy_highpage(page, ol 687 copy_highpage(page, old_page);
688 *old = addr | (*old & 688 *old = addr | (*old & ~PAGE_MASK);
689 689
690 /* The old page I have 690 /* The old page I have found cannot be a
691 * destination page, s 691 * destination page, so return it if it's
692 * gfp_flags honor the 692 * gfp_flags honor the ones passed in.
693 */ 693 */
694 if (!(gfp_mask & __GFP 694 if (!(gfp_mask & __GFP_HIGHMEM) &&
695 PageHighMem(old_pa 695 PageHighMem(old_page)) {
696 kimage_free_pa 696 kimage_free_pages(old_page);
697 continue; 697 continue;
698 } 698 }
699 page = old_page; 699 page = old_page;
700 break; 700 break;
701 } 701 }
702 /* Place the page on the desti 702 /* Place the page on the destination list, to be used later */
703 list_add(&page->lru, &image->d 703 list_add(&page->lru, &image->dest_pages);
704 } 704 }
705 705
706 return page; 706 return page;
707 } 707 }
708 708
709 static int kimage_load_normal_segment(struct k 709 static int kimage_load_normal_segment(struct kimage *image,
710 struc 710 struct kexec_segment *segment)
711 { 711 {
712 unsigned long maddr; 712 unsigned long maddr;
713 size_t ubytes, mbytes; 713 size_t ubytes, mbytes;
714 int result; 714 int result;
715 unsigned char __user *buf = NULL; 715 unsigned char __user *buf = NULL;
716 unsigned char *kbuf = NULL; 716 unsigned char *kbuf = NULL;
717 717
718 if (image->file_mode) 718 if (image->file_mode)
719 kbuf = segment->kbuf; 719 kbuf = segment->kbuf;
720 else 720 else
721 buf = segment->buf; 721 buf = segment->buf;
722 ubytes = segment->bufsz; 722 ubytes = segment->bufsz;
723 mbytes = segment->memsz; 723 mbytes = segment->memsz;
724 maddr = segment->mem; 724 maddr = segment->mem;
725 725
726 result = kimage_set_destination(image, 726 result = kimage_set_destination(image, maddr);
727 if (result < 0) 727 if (result < 0)
728 goto out; 728 goto out;
729 729
730 while (mbytes) { 730 while (mbytes) {
731 struct page *page; 731 struct page *page;
732 char *ptr; 732 char *ptr;
733 size_t uchunk, mchunk; 733 size_t uchunk, mchunk;
734 734
735 page = kimage_alloc_page(image 735 page = kimage_alloc_page(image, GFP_HIGHUSER, maddr);
736 if (!page) { 736 if (!page) {
737 result = -ENOMEM; 737 result = -ENOMEM;
738 goto out; 738 goto out;
739 } 739 }
740 result = kimage_add_page(image 740 result = kimage_add_page(image, page_to_boot_pfn(page)
741 741 << PAGE_SHIFT);
742 if (result < 0) 742 if (result < 0)
743 goto out; 743 goto out;
744 744
745 ptr = kmap_local_page(page); 745 ptr = kmap_local_page(page);
746 /* Start with a clear page */ 746 /* Start with a clear page */
747 clear_page(ptr); 747 clear_page(ptr);
748 ptr += maddr & ~PAGE_MASK; 748 ptr += maddr & ~PAGE_MASK;
749 mchunk = min_t(size_t, mbytes, 749 mchunk = min_t(size_t, mbytes,
750 PAGE_SIZE - (m 750 PAGE_SIZE - (maddr & ~PAGE_MASK));
751 uchunk = min(ubytes, mchunk); 751 uchunk = min(ubytes, mchunk);
752 752
753 if (uchunk) { 753 if (uchunk) {
754 /* For file based kexe 754 /* For file based kexec, source pages are in kernel memory */
755 if (image->file_mode) 755 if (image->file_mode)
756 memcpy(ptr, kb 756 memcpy(ptr, kbuf, uchunk);
757 else 757 else
758 result = copy_ 758 result = copy_from_user(ptr, buf, uchunk);
759 ubytes -= uchunk; 759 ubytes -= uchunk;
760 if (image->file_mode) 760 if (image->file_mode)
761 kbuf += uchunk 761 kbuf += uchunk;
762 else 762 else
763 buf += uchunk; 763 buf += uchunk;
764 } 764 }
765 kunmap_local(ptr); 765 kunmap_local(ptr);
766 if (result) { 766 if (result) {
767 result = -EFAULT; 767 result = -EFAULT;
768 goto out; 768 goto out;
769 } 769 }
770 maddr += mchunk; 770 maddr += mchunk;
771 mbytes -= mchunk; 771 mbytes -= mchunk;
772 772
773 cond_resched(); 773 cond_resched();
774 } 774 }
775 out: 775 out:
776 return result; 776 return result;
777 } 777 }
778 778
779 #ifdef CONFIG_CRASH_DUMP 779 #ifdef CONFIG_CRASH_DUMP
780 static int kimage_load_crash_segment(struct ki 780 static int kimage_load_crash_segment(struct kimage *image,
781 struct 781 struct kexec_segment *segment)
782 { 782 {
783 /* For crash dumps kernels we simply c 783 /* For crash dumps kernels we simply copy the data from
784 * user space to it's destination. 784 * user space to it's destination.
785 * We do things a page at a time for t 785 * We do things a page at a time for the sake of kmap.
786 */ 786 */
787 unsigned long maddr; 787 unsigned long maddr;
788 size_t ubytes, mbytes; 788 size_t ubytes, mbytes;
789 int result; 789 int result;
790 unsigned char __user *buf = NULL; 790 unsigned char __user *buf = NULL;
791 unsigned char *kbuf = NULL; 791 unsigned char *kbuf = NULL;
792 792
793 result = 0; 793 result = 0;
794 if (image->file_mode) 794 if (image->file_mode)
795 kbuf = segment->kbuf; 795 kbuf = segment->kbuf;
796 else 796 else
797 buf = segment->buf; 797 buf = segment->buf;
798 ubytes = segment->bufsz; 798 ubytes = segment->bufsz;
799 mbytes = segment->memsz; 799 mbytes = segment->memsz;
800 maddr = segment->mem; 800 maddr = segment->mem;
801 while (mbytes) { 801 while (mbytes) {
802 struct page *page; 802 struct page *page;
803 char *ptr; 803 char *ptr;
804 size_t uchunk, mchunk; 804 size_t uchunk, mchunk;
805 805
806 page = boot_pfn_to_page(maddr 806 page = boot_pfn_to_page(maddr >> PAGE_SHIFT);
807 if (!page) { 807 if (!page) {
808 result = -ENOMEM; 808 result = -ENOMEM;
809 goto out; 809 goto out;
810 } 810 }
811 arch_kexec_post_alloc_pages(pa 811 arch_kexec_post_alloc_pages(page_address(page), 1, 0);
812 ptr = kmap_local_page(page); 812 ptr = kmap_local_page(page);
813 ptr += maddr & ~PAGE_MASK; 813 ptr += maddr & ~PAGE_MASK;
814 mchunk = min_t(size_t, mbytes, 814 mchunk = min_t(size_t, mbytes,
815 PAGE_SIZE - (m 815 PAGE_SIZE - (maddr & ~PAGE_MASK));
816 uchunk = min(ubytes, mchunk); 816 uchunk = min(ubytes, mchunk);
817 if (mchunk > uchunk) { 817 if (mchunk > uchunk) {
818 /* Zero the trailing p 818 /* Zero the trailing part of the page */
819 memset(ptr + uchunk, 0 819 memset(ptr + uchunk, 0, mchunk - uchunk);
820 } 820 }
821 821
822 if (uchunk) { 822 if (uchunk) {
823 /* For file based kexe 823 /* For file based kexec, source pages are in kernel memory */
824 if (image->file_mode) 824 if (image->file_mode)
825 memcpy(ptr, kb 825 memcpy(ptr, kbuf, uchunk);
826 else 826 else
827 result = copy_ 827 result = copy_from_user(ptr, buf, uchunk);
828 ubytes -= uchunk; 828 ubytes -= uchunk;
829 if (image->file_mode) 829 if (image->file_mode)
830 kbuf += uchunk 830 kbuf += uchunk;
831 else 831 else
832 buf += uchunk; 832 buf += uchunk;
833 } 833 }
834 kexec_flush_icache_page(page); 834 kexec_flush_icache_page(page);
835 kunmap_local(ptr); 835 kunmap_local(ptr);
836 arch_kexec_pre_free_pages(page 836 arch_kexec_pre_free_pages(page_address(page), 1);
837 if (result) { 837 if (result) {
838 result = -EFAULT; 838 result = -EFAULT;
839 goto out; 839 goto out;
840 } 840 }
841 maddr += mchunk; 841 maddr += mchunk;
842 mbytes -= mchunk; 842 mbytes -= mchunk;
843 843
844 cond_resched(); 844 cond_resched();
845 } 845 }
846 out: 846 out:
847 return result; 847 return result;
848 } 848 }
849 #endif 849 #endif
850 850
851 int kimage_load_segment(struct kimage *image, 851 int kimage_load_segment(struct kimage *image,
852 struct kexec_s 852 struct kexec_segment *segment)
853 { 853 {
854 int result = -ENOMEM; 854 int result = -ENOMEM;
855 855
856 switch (image->type) { 856 switch (image->type) {
857 case KEXEC_TYPE_DEFAULT: 857 case KEXEC_TYPE_DEFAULT:
858 result = kimage_load_normal_se 858 result = kimage_load_normal_segment(image, segment);
859 break; 859 break;
860 #ifdef CONFIG_CRASH_DUMP 860 #ifdef CONFIG_CRASH_DUMP
861 case KEXEC_TYPE_CRASH: 861 case KEXEC_TYPE_CRASH:
862 result = kimage_load_crash_seg 862 result = kimage_load_crash_segment(image, segment);
863 break; 863 break;
864 #endif 864 #endif
865 } 865 }
866 866
867 return result; 867 return result;
868 } 868 }
869 869
870 struct kexec_load_limit { 870 struct kexec_load_limit {
871 /* Mutex protects the limit count. */ 871 /* Mutex protects the limit count. */
872 struct mutex mutex; 872 struct mutex mutex;
873 int limit; 873 int limit;
874 }; 874 };
875 875
876 static struct kexec_load_limit load_limit_rebo 876 static struct kexec_load_limit load_limit_reboot = {
877 .mutex = __MUTEX_INITIALIZER(load_limi 877 .mutex = __MUTEX_INITIALIZER(load_limit_reboot.mutex),
878 .limit = -1, 878 .limit = -1,
879 }; 879 };
880 880
881 static struct kexec_load_limit load_limit_pani 881 static struct kexec_load_limit load_limit_panic = {
882 .mutex = __MUTEX_INITIALIZER(load_limi 882 .mutex = __MUTEX_INITIALIZER(load_limit_panic.mutex),
883 .limit = -1, 883 .limit = -1,
884 }; 884 };
885 885
886 struct kimage *kexec_image; 886 struct kimage *kexec_image;
887 struct kimage *kexec_crash_image; 887 struct kimage *kexec_crash_image;
888 static int kexec_load_disabled; 888 static int kexec_load_disabled;
889 889
890 #ifdef CONFIG_SYSCTL 890 #ifdef CONFIG_SYSCTL
891 static int kexec_limit_handler(const struct ct !! 891 static int kexec_limit_handler(struct ctl_table *table, int write,
892 void *buffer, s 892 void *buffer, size_t *lenp, loff_t *ppos)
893 { 893 {
894 struct kexec_load_limit *limit = table 894 struct kexec_load_limit *limit = table->data;
895 int val; 895 int val;
896 struct ctl_table tmp = { 896 struct ctl_table tmp = {
897 .data = &val, 897 .data = &val,
898 .maxlen = sizeof(val), 898 .maxlen = sizeof(val),
899 .mode = table->mode, 899 .mode = table->mode,
900 }; 900 };
901 int ret; 901 int ret;
902 902
903 if (write) { 903 if (write) {
904 ret = proc_dointvec(&tmp, writ 904 ret = proc_dointvec(&tmp, write, buffer, lenp, ppos);
905 if (ret) 905 if (ret)
906 return ret; 906 return ret;
907 907
908 if (val < 0) 908 if (val < 0)
909 return -EINVAL; 909 return -EINVAL;
910 910
911 mutex_lock(&limit->mutex); 911 mutex_lock(&limit->mutex);
912 if (limit->limit != -1 && val 912 if (limit->limit != -1 && val >= limit->limit)
913 ret = -EINVAL; 913 ret = -EINVAL;
914 else 914 else
915 limit->limit = val; 915 limit->limit = val;
916 mutex_unlock(&limit->mutex); 916 mutex_unlock(&limit->mutex);
917 917
918 return ret; 918 return ret;
919 } 919 }
920 920
921 mutex_lock(&limit->mutex); 921 mutex_lock(&limit->mutex);
922 val = limit->limit; 922 val = limit->limit;
923 mutex_unlock(&limit->mutex); 923 mutex_unlock(&limit->mutex);
924 924
925 return proc_dointvec(&tmp, write, buff 925 return proc_dointvec(&tmp, write, buffer, lenp, ppos);
926 } 926 }
927 927
928 static struct ctl_table kexec_core_sysctls[] = 928 static struct ctl_table kexec_core_sysctls[] = {
929 { 929 {
930 .procname = "kexec_load_ 930 .procname = "kexec_load_disabled",
931 .data = &kexec_load_ 931 .data = &kexec_load_disabled,
932 .maxlen = sizeof(int), 932 .maxlen = sizeof(int),
933 .mode = 0644, 933 .mode = 0644,
934 /* only handle a transition fr 934 /* only handle a transition from default "" to "1" */
935 .proc_handler = proc_dointve 935 .proc_handler = proc_dointvec_minmax,
936 .extra1 = SYSCTL_ONE, 936 .extra1 = SYSCTL_ONE,
937 .extra2 = SYSCTL_ONE, 937 .extra2 = SYSCTL_ONE,
938 }, 938 },
939 { 939 {
940 .procname = "kexec_load_ 940 .procname = "kexec_load_limit_panic",
941 .data = &load_limit_ 941 .data = &load_limit_panic,
942 .mode = 0644, 942 .mode = 0644,
943 .proc_handler = kexec_limit_ 943 .proc_handler = kexec_limit_handler,
944 }, 944 },
945 { 945 {
946 .procname = "kexec_load_ 946 .procname = "kexec_load_limit_reboot",
947 .data = &load_limit_ 947 .data = &load_limit_reboot,
948 .mode = 0644, 948 .mode = 0644,
949 .proc_handler = kexec_limit_ 949 .proc_handler = kexec_limit_handler,
950 }, 950 },
>> 951 { }
951 }; 952 };
952 953
953 static int __init kexec_core_sysctl_init(void) 954 static int __init kexec_core_sysctl_init(void)
954 { 955 {
955 register_sysctl_init("kernel", kexec_c 956 register_sysctl_init("kernel", kexec_core_sysctls);
956 return 0; 957 return 0;
957 } 958 }
958 late_initcall(kexec_core_sysctl_init); 959 late_initcall(kexec_core_sysctl_init);
959 #endif 960 #endif
960 961
961 bool kexec_load_permitted(int kexec_image_type 962 bool kexec_load_permitted(int kexec_image_type)
962 { 963 {
963 struct kexec_load_limit *limit; 964 struct kexec_load_limit *limit;
964 965
965 /* 966 /*
966 * Only the superuser can use the kexe 967 * Only the superuser can use the kexec syscall and if it has not
967 * been disabled. 968 * been disabled.
968 */ 969 */
969 if (!capable(CAP_SYS_BOOT) || kexec_lo 970 if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
970 return false; 971 return false;
971 972
972 /* Check limit counter and decrease it 973 /* Check limit counter and decrease it.*/
973 limit = (kexec_image_type == KEXEC_TYP 974 limit = (kexec_image_type == KEXEC_TYPE_CRASH) ?
974 &load_limit_panic : &load_limi 975 &load_limit_panic : &load_limit_reboot;
975 mutex_lock(&limit->mutex); 976 mutex_lock(&limit->mutex);
976 if (!limit->limit) { 977 if (!limit->limit) {
977 mutex_unlock(&limit->mutex); 978 mutex_unlock(&limit->mutex);
978 return false; 979 return false;
979 } 980 }
980 if (limit->limit != -1) 981 if (limit->limit != -1)
981 limit->limit--; 982 limit->limit--;
982 mutex_unlock(&limit->mutex); 983 mutex_unlock(&limit->mutex);
983 984
984 return true; 985 return true;
985 } 986 }
986 987
987 /* 988 /*
988 * Move into place and start executing a prelo 989 * Move into place and start executing a preloaded standalone
989 * executable. If nothing was preloaded retur 990 * executable. If nothing was preloaded return an error.
990 */ 991 */
991 int kernel_kexec(void) 992 int kernel_kexec(void)
992 { 993 {
993 int error = 0; 994 int error = 0;
994 995
995 if (!kexec_trylock()) 996 if (!kexec_trylock())
996 return -EBUSY; 997 return -EBUSY;
997 if (!kexec_image) { 998 if (!kexec_image) {
998 error = -EINVAL; 999 error = -EINVAL;
999 goto Unlock; 1000 goto Unlock;
1000 } 1001 }
1001 1002
1002 #ifdef CONFIG_KEXEC_JUMP 1003 #ifdef CONFIG_KEXEC_JUMP
1003 if (kexec_image->preserve_context) { 1004 if (kexec_image->preserve_context) {
1004 pm_prepare_console(); 1005 pm_prepare_console();
1005 error = freeze_processes(); 1006 error = freeze_processes();
1006 if (error) { 1007 if (error) {
1007 error = -EBUSY; 1008 error = -EBUSY;
1008 goto Restore_console; 1009 goto Restore_console;
1009 } 1010 }
1010 suspend_console(); 1011 suspend_console();
1011 error = dpm_suspend_start(PMS 1012 error = dpm_suspend_start(PMSG_FREEZE);
1012 if (error) 1013 if (error)
1013 goto Resume_console; 1014 goto Resume_console;
1014 /* At this point, dpm_suspend 1015 /* At this point, dpm_suspend_start() has been called,
1015 * but *not* dpm_suspend_end( 1016 * but *not* dpm_suspend_end(). We *must* call
1016 * dpm_suspend_end() now. Ot 1017 * dpm_suspend_end() now. Otherwise, drivers for
1017 * some devices (e.g. interru 1018 * some devices (e.g. interrupt controllers) become
1018 * desynchronized with the ac 1019 * desynchronized with the actual state of the
1019 * hardware at resume time, a 1020 * hardware at resume time, and evil weirdness ensues.
1020 */ 1021 */
1021 error = dpm_suspend_end(PMSG_ 1022 error = dpm_suspend_end(PMSG_FREEZE);
1022 if (error) 1023 if (error)
1023 goto Resume_devices; 1024 goto Resume_devices;
1024 error = suspend_disable_secon 1025 error = suspend_disable_secondary_cpus();
1025 if (error) 1026 if (error)
1026 goto Enable_cpus; 1027 goto Enable_cpus;
1027 local_irq_disable(); 1028 local_irq_disable();
1028 error = syscore_suspend(); 1029 error = syscore_suspend();
1029 if (error) 1030 if (error)
1030 goto Enable_irqs; 1031 goto Enable_irqs;
1031 } else 1032 } else
1032 #endif 1033 #endif
1033 { 1034 {
1034 kexec_in_progress = true; 1035 kexec_in_progress = true;
1035 kernel_restart_prepare("kexec 1036 kernel_restart_prepare("kexec reboot");
1036 migrate_to_reboot_cpu(); 1037 migrate_to_reboot_cpu();
1037 syscore_shutdown(); 1038 syscore_shutdown();
1038 1039
1039 /* 1040 /*
1040 * migrate_to_reboot_cpu() di 1041 * migrate_to_reboot_cpu() disables CPU hotplug assuming that
1041 * no further code needs to u 1042 * no further code needs to use CPU hotplug (which is true in
1042 * the reboot case). However, 1043 * the reboot case). However, the kexec path depends on using
1043 * CPU hotplug again; so re-e 1044 * CPU hotplug again; so re-enable it here.
1044 */ 1045 */
1045 cpu_hotplug_enable(); 1046 cpu_hotplug_enable();
1046 pr_notice("Starting new kerne 1047 pr_notice("Starting new kernel\n");
1047 machine_shutdown(); 1048 machine_shutdown();
1048 } 1049 }
1049 1050
1050 kmsg_dump(KMSG_DUMP_SHUTDOWN); 1051 kmsg_dump(KMSG_DUMP_SHUTDOWN);
1051 machine_kexec(kexec_image); 1052 machine_kexec(kexec_image);
1052 1053
1053 #ifdef CONFIG_KEXEC_JUMP 1054 #ifdef CONFIG_KEXEC_JUMP
1054 if (kexec_image->preserve_context) { 1055 if (kexec_image->preserve_context) {
1055 syscore_resume(); 1056 syscore_resume();
1056 Enable_irqs: 1057 Enable_irqs:
1057 local_irq_enable(); 1058 local_irq_enable();
1058 Enable_cpus: 1059 Enable_cpus:
1059 suspend_enable_secondary_cpus 1060 suspend_enable_secondary_cpus();
1060 dpm_resume_start(PMSG_RESTORE 1061 dpm_resume_start(PMSG_RESTORE);
1061 Resume_devices: 1062 Resume_devices:
1062 dpm_resume_end(PMSG_RESTORE); 1063 dpm_resume_end(PMSG_RESTORE);
1063 Resume_console: 1064 Resume_console:
1064 resume_console(); 1065 resume_console();
1065 thaw_processes(); 1066 thaw_processes();
1066 Restore_console: 1067 Restore_console:
1067 pm_restore_console(); 1068 pm_restore_console();
1068 } 1069 }
1069 #endif 1070 #endif
1070 1071
1071 Unlock: 1072 Unlock:
1072 kexec_unlock(); 1073 kexec_unlock();
1073 return error; 1074 return error;
1074 } 1075 }
1075 1076
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.