Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 1 | /* |
| 2 | * kexec.c - kexec system call core code. |
| 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 | |
Minfei Huang | de90a6b | 2015-11-06 16:32:45 -0800 | [diff] [blame] | 9 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 10 | |
| 11 | #include <linux/capability.h> |
| 12 | #include <linux/mm.h> |
| 13 | #include <linux/file.h> |
| 14 | #include <linux/slab.h> |
| 15 | #include <linux/fs.h> |
| 16 | #include <linux/kexec.h> |
| 17 | #include <linux/mutex.h> |
| 18 | #include <linux/list.h> |
| 19 | #include <linux/highmem.h> |
| 20 | #include <linux/syscalls.h> |
| 21 | #include <linux/reboot.h> |
| 22 | #include <linux/ioport.h> |
| 23 | #include <linux/hardirq.h> |
| 24 | #include <linux/elf.h> |
| 25 | #include <linux/elfcore.h> |
| 26 | #include <linux/utsname.h> |
| 27 | #include <linux/numa.h> |
| 28 | #include <linux/suspend.h> |
| 29 | #include <linux/device.h> |
| 30 | #include <linux/freezer.h> |
| 31 | #include <linux/pm.h> |
| 32 | #include <linux/cpu.h> |
| 33 | #include <linux/uaccess.h> |
| 34 | #include <linux/io.h> |
| 35 | #include <linux/console.h> |
| 36 | #include <linux/vmalloc.h> |
| 37 | #include <linux/swap.h> |
| 38 | #include <linux/syscore_ops.h> |
| 39 | #include <linux/compiler.h> |
| 40 | #include <linux/hugetlb.h> |
Josh Poimboeuf | c207aee | 2017-06-28 10:11:06 -0500 | [diff] [blame] | 41 | #include <linux/frame.h> |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 42 | |
| 43 | #include <asm/page.h> |
| 44 | #include <asm/sections.h> |
| 45 | |
| 46 | #include <crypto/hash.h> |
| 47 | #include <crypto/sha.h> |
| 48 | #include "kexec_internal.h" |
| 49 | |
| 50 | DEFINE_MUTEX(kexec_mutex); |
| 51 | |
| 52 | /* Per cpu memory for storing cpu states in case of system crash. */ |
| 53 | note_buf_t __percpu *crash_notes; |
| 54 | |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 55 | /* Flag to indicate we are going to kexec a new kernel */ |
| 56 | bool kexec_in_progress = false; |
| 57 | |
| 58 | |
| 59 | /* Location of the reserved area for the crash kernel */ |
| 60 | struct resource crashk_res = { |
| 61 | .name = "Crash kernel", |
| 62 | .start = 0, |
| 63 | .end = 0, |
Toshi Kani | 1a085d0 | 2016-01-26 21:57:23 +0100 | [diff] [blame] | 64 | .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, |
| 65 | .desc = IORES_DESC_CRASH_KERNEL |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 66 | }; |
| 67 | struct resource crashk_low_res = { |
| 68 | .name = "Crash kernel", |
| 69 | .start = 0, |
| 70 | .end = 0, |
Toshi Kani | 1a085d0 | 2016-01-26 21:57:23 +0100 | [diff] [blame] | 71 | .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, |
| 72 | .desc = IORES_DESC_CRASH_KERNEL |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 73 | }; |
| 74 | |
| 75 | int kexec_should_crash(struct task_struct *p) |
| 76 | { |
| 77 | /* |
| 78 | * If crash_kexec_post_notifiers is enabled, don't run |
| 79 | * crash_kexec() here yet, which must be run after panic |
| 80 | * notifiers in panic(). |
| 81 | */ |
| 82 | if (crash_kexec_post_notifiers) |
| 83 | return 0; |
| 84 | /* |
| 85 | * There are 4 panic() calls in do_exit() path, each of which |
| 86 | * corresponds to each of these 4 conditions. |
| 87 | */ |
| 88 | if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops) |
| 89 | return 1; |
| 90 | return 0; |
| 91 | } |
| 92 | |
Petr Tesarik | 21db79e | 2016-08-02 14:06:16 -0700 | [diff] [blame] | 93 | int kexec_crash_loaded(void) |
| 94 | { |
| 95 | return !!kexec_crash_image; |
| 96 | } |
| 97 | EXPORT_SYMBOL_GPL(kexec_crash_loaded); |
| 98 | |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 99 | /* |
| 100 | * When kexec transitions to the new kernel there is a one-to-one |
| 101 | * mapping between physical and virtual addresses. On processors |
| 102 | * where you can disable the MMU this is trivial, and easy. For |
| 103 | * others it is still a simple predictable page table to setup. |
| 104 | * |
| 105 | * In that environment kexec copies the new kernel to its final |
| 106 | * resting place. This means I can only support memory whose |
| 107 | * physical address can fit in an unsigned long. In particular |
| 108 | * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled. |
| 109 | * If the assembly stub has more restrictive requirements |
| 110 | * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be |
| 111 | * defined more restrictively in <asm/kexec.h>. |
| 112 | * |
| 113 | * The code for the transition from the current kernel to the |
| 114 | * the new kernel is placed in the control_code_buffer, whose size |
| 115 | * is given by KEXEC_CONTROL_PAGE_SIZE. In the best case only a single |
| 116 | * page of memory is necessary, but some architectures require more. |
| 117 | * Because this memory must be identity mapped in the transition from |
| 118 | * virtual to physical addresses it must live in the range |
| 119 | * 0 - TASK_SIZE, as only the user space mappings are arbitrarily |
| 120 | * modifiable. |
| 121 | * |
| 122 | * The assembly stub in the control code buffer is passed a linked list |
| 123 | * of descriptor pages detailing the source pages of the new kernel, |
| 124 | * and the destination addresses of those source pages. As this data |
| 125 | * structure is not used in the context of the current OS, it must |
| 126 | * be self-contained. |
| 127 | * |
| 128 | * The code has been made to work with highmem pages and will use a |
| 129 | * destination page in its final resting place (if it happens |
| 130 | * to allocate it). The end product of this is that most of the |
| 131 | * physical address space, and most of RAM can be used. |
| 132 | * |
| 133 | * Future directions include: |
| 134 | * - allocating a page table with the control code buffer identity |
| 135 | * mapped, to simplify machine_kexec and make kexec_on_panic more |
| 136 | * reliable. |
| 137 | */ |
| 138 | |
| 139 | /* |
| 140 | * KIMAGE_NO_DEST is an impossible destination address..., for |
| 141 | * allocating pages whose destination address we do not care about. |
| 142 | */ |
| 143 | #define KIMAGE_NO_DEST (-1UL) |
zhong jiang | 1730f14 | 2016-08-02 14:06:22 -0700 | [diff] [blame] | 144 | #define PAGE_COUNT(x) (((x) + PAGE_SIZE - 1) >> PAGE_SHIFT) |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 145 | |
| 146 | static struct page *kimage_alloc_page(struct kimage *image, |
| 147 | gfp_t gfp_mask, |
| 148 | unsigned long dest); |
| 149 | |
| 150 | int sanity_check_segment_list(struct kimage *image) |
| 151 | { |
Minfei Huang | 4caf961 | 2016-08-02 14:05:45 -0700 | [diff] [blame] | 152 | int i; |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 153 | unsigned long nr_segments = image->nr_segments; |
zhong jiang | 1730f14 | 2016-08-02 14:06:22 -0700 | [diff] [blame] | 154 | unsigned long total_pages = 0; |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 155 | |
| 156 | /* |
| 157 | * Verify we have good destination addresses. The caller is |
| 158 | * responsible for making certain we don't attempt to load |
| 159 | * the new image into invalid or reserved areas of RAM. This |
| 160 | * just verifies it is an address we can use. |
| 161 | * |
| 162 | * Since the kernel does everything in page size chunks ensure |
| 163 | * the destination addresses are page aligned. Too many |
| 164 | * special cases crop of when we don't do this. The most |
| 165 | * insidious is getting overlapping destination addresses |
| 166 | * simply because addresses are changed to page size |
| 167 | * granularity. |
| 168 | */ |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 169 | for (i = 0; i < nr_segments; i++) { |
| 170 | unsigned long mstart, mend; |
| 171 | |
| 172 | mstart = image->segment[i].mem; |
| 173 | mend = mstart + image->segment[i].memsz; |
Russell King | 465d377 | 2016-08-02 14:05:57 -0700 | [diff] [blame] | 174 | if (mstart > mend) |
| 175 | return -EADDRNOTAVAIL; |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 176 | if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK)) |
Minfei Huang | 4caf961 | 2016-08-02 14:05:45 -0700 | [diff] [blame] | 177 | return -EADDRNOTAVAIL; |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 178 | if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT) |
Minfei Huang | 4caf961 | 2016-08-02 14:05:45 -0700 | [diff] [blame] | 179 | return -EADDRNOTAVAIL; |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 180 | } |
| 181 | |
| 182 | /* Verify our destination addresses do not overlap. |
| 183 | * If we alloed overlapping destination addresses |
| 184 | * through very weird things can happen with no |
| 185 | * easy explanation as one segment stops on another. |
| 186 | */ |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 187 | for (i = 0; i < nr_segments; i++) { |
| 188 | unsigned long mstart, mend; |
| 189 | unsigned long j; |
| 190 | |
| 191 | mstart = image->segment[i].mem; |
| 192 | mend = mstart + image->segment[i].memsz; |
| 193 | for (j = 0; j < i; j++) { |
| 194 | unsigned long pstart, pend; |
| 195 | |
| 196 | pstart = image->segment[j].mem; |
| 197 | pend = pstart + image->segment[j].memsz; |
| 198 | /* Do the segments overlap ? */ |
| 199 | if ((mend > pstart) && (mstart < pend)) |
Minfei Huang | 4caf961 | 2016-08-02 14:05:45 -0700 | [diff] [blame] | 200 | return -EINVAL; |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 201 | } |
| 202 | } |
| 203 | |
| 204 | /* Ensure our buffer sizes are strictly less than |
| 205 | * our memory sizes. This should always be the case, |
| 206 | * and it is easier to check up front than to be surprised |
| 207 | * later on. |
| 208 | */ |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 209 | for (i = 0; i < nr_segments; i++) { |
| 210 | if (image->segment[i].bufsz > image->segment[i].memsz) |
Minfei Huang | 4caf961 | 2016-08-02 14:05:45 -0700 | [diff] [blame] | 211 | return -EINVAL; |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 212 | } |
| 213 | |
| 214 | /* |
zhong jiang | 1730f14 | 2016-08-02 14:06:22 -0700 | [diff] [blame] | 215 | * Verify that no more than half of memory will be consumed. If the |
| 216 | * request from userspace is too large, a large amount of time will be |
| 217 | * wasted allocating pages, which can cause a soft lockup. |
| 218 | */ |
| 219 | for (i = 0; i < nr_segments; i++) { |
| 220 | if (PAGE_COUNT(image->segment[i].memsz) > totalram_pages / 2) |
| 221 | return -EINVAL; |
| 222 | |
| 223 | total_pages += PAGE_COUNT(image->segment[i].memsz); |
| 224 | } |
| 225 | |
| 226 | if (total_pages > totalram_pages / 2) |
| 227 | return -EINVAL; |
| 228 | |
| 229 | /* |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 230 | * Verify we have good destination addresses. Normally |
| 231 | * the caller is responsible for making certain we don't |
| 232 | * attempt to load the new image into invalid or reserved |
| 233 | * areas of RAM. But crash kernels are preloaded into a |
| 234 | * reserved area of ram. We must ensure the addresses |
| 235 | * are in the reserved area otherwise preloading the |
| 236 | * kernel could corrupt things. |
| 237 | */ |
| 238 | |
| 239 | if (image->type == KEXEC_TYPE_CRASH) { |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 240 | for (i = 0; i < nr_segments; i++) { |
| 241 | unsigned long mstart, mend; |
| 242 | |
| 243 | mstart = image->segment[i].mem; |
| 244 | mend = mstart + image->segment[i].memsz - 1; |
| 245 | /* Ensure we are within the crash kernel limits */ |
Russell King | 43546d8 | 2016-08-02 14:06:04 -0700 | [diff] [blame] | 246 | if ((mstart < phys_to_boot_phys(crashk_res.start)) || |
| 247 | (mend > phys_to_boot_phys(crashk_res.end))) |
Minfei Huang | 4caf961 | 2016-08-02 14:05:45 -0700 | [diff] [blame] | 248 | return -EADDRNOTAVAIL; |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 249 | } |
| 250 | } |
| 251 | |
| 252 | return 0; |
| 253 | } |
| 254 | |
| 255 | struct kimage *do_kimage_alloc_init(void) |
| 256 | { |
| 257 | struct kimage *image; |
| 258 | |
| 259 | /* Allocate a controlling structure */ |
| 260 | image = kzalloc(sizeof(*image), GFP_KERNEL); |
| 261 | if (!image) |
| 262 | return NULL; |
| 263 | |
| 264 | image->head = 0; |
| 265 | image->entry = &image->head; |
| 266 | image->last_entry = &image->head; |
| 267 | image->control_page = ~0; /* By default this does not apply */ |
| 268 | image->type = KEXEC_TYPE_DEFAULT; |
| 269 | |
| 270 | /* Initialize the list of control pages */ |
| 271 | INIT_LIST_HEAD(&image->control_pages); |
| 272 | |
| 273 | /* Initialize the list of destination pages */ |
| 274 | INIT_LIST_HEAD(&image->dest_pages); |
| 275 | |
| 276 | /* Initialize the list of unusable pages */ |
| 277 | INIT_LIST_HEAD(&image->unusable_pages); |
| 278 | |
| 279 | return image; |
| 280 | } |
| 281 | |
| 282 | int kimage_is_destination_range(struct kimage *image, |
| 283 | unsigned long start, |
| 284 | unsigned long end) |
| 285 | { |
| 286 | unsigned long i; |
| 287 | |
| 288 | for (i = 0; i < image->nr_segments; i++) { |
| 289 | unsigned long mstart, mend; |
| 290 | |
| 291 | mstart = image->segment[i].mem; |
| 292 | mend = mstart + image->segment[i].memsz; |
| 293 | if ((end > mstart) && (start < mend)) |
| 294 | return 1; |
| 295 | } |
| 296 | |
| 297 | return 0; |
| 298 | } |
| 299 | |
| 300 | static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order) |
| 301 | { |
| 302 | struct page *pages; |
| 303 | |
Tom Lendacky | bba4ed0 | 2017-07-17 16:10:28 -0500 | [diff] [blame] | 304 | pages = alloc_pages(gfp_mask & ~__GFP_ZERO, order); |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 305 | if (pages) { |
| 306 | unsigned int count, i; |
| 307 | |
| 308 | pages->mapping = NULL; |
| 309 | set_page_private(pages, order); |
| 310 | count = 1 << order; |
| 311 | for (i = 0; i < count; i++) |
| 312 | SetPageReserved(pages + i); |
Tom Lendacky | bba4ed0 | 2017-07-17 16:10:28 -0500 | [diff] [blame] | 313 | |
| 314 | arch_kexec_post_alloc_pages(page_address(pages), count, |
| 315 | gfp_mask); |
| 316 | |
| 317 | if (gfp_mask & __GFP_ZERO) |
| 318 | for (i = 0; i < count; i++) |
| 319 | clear_highpage(pages + i); |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 320 | } |
| 321 | |
| 322 | return pages; |
| 323 | } |
| 324 | |
| 325 | static void kimage_free_pages(struct page *page) |
| 326 | { |
| 327 | unsigned int order, count, i; |
| 328 | |
| 329 | order = page_private(page); |
| 330 | count = 1 << order; |
Tom Lendacky | bba4ed0 | 2017-07-17 16:10:28 -0500 | [diff] [blame] | 331 | |
| 332 | arch_kexec_pre_free_pages(page_address(page), count); |
| 333 | |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 334 | for (i = 0; i < count; i++) |
| 335 | ClearPageReserved(page + i); |
| 336 | __free_pages(page, order); |
| 337 | } |
| 338 | |
| 339 | void kimage_free_page_list(struct list_head *list) |
| 340 | { |
Geliang Tang | 2b24692 | 2016-01-20 15:00:34 -0800 | [diff] [blame] | 341 | struct page *page, *next; |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 342 | |
Geliang Tang | 2b24692 | 2016-01-20 15:00:34 -0800 | [diff] [blame] | 343 | list_for_each_entry_safe(page, next, list, lru) { |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 344 | list_del(&page->lru); |
| 345 | kimage_free_pages(page); |
| 346 | } |
| 347 | } |
| 348 | |
| 349 | static struct page *kimage_alloc_normal_control_pages(struct kimage *image, |
| 350 | unsigned int order) |
| 351 | { |
| 352 | /* Control pages are special, they are the intermediaries |
| 353 | * that are needed while we copy the rest of the pages |
| 354 | * to their final resting place. As such they must |
| 355 | * not conflict with either the destination addresses |
| 356 | * or memory the kernel is already using. |
| 357 | * |
| 358 | * The only case where we really need more than one of |
| 359 | * these are for architectures where we cannot disable |
| 360 | * the MMU and must instead generate an identity mapped |
| 361 | * page table for all of the memory. |
| 362 | * |
| 363 | * At worst this runs in O(N) of the image size. |
| 364 | */ |
| 365 | struct list_head extra_pages; |
| 366 | struct page *pages; |
| 367 | unsigned int count; |
| 368 | |
| 369 | count = 1 << order; |
| 370 | INIT_LIST_HEAD(&extra_pages); |
| 371 | |
| 372 | /* Loop while I can allocate a page and the page allocated |
| 373 | * is a destination page. |
| 374 | */ |
| 375 | do { |
| 376 | unsigned long pfn, epfn, addr, eaddr; |
| 377 | |
| 378 | pages = kimage_alloc_pages(KEXEC_CONTROL_MEMORY_GFP, order); |
| 379 | if (!pages) |
| 380 | break; |
Russell King | 43546d8 | 2016-08-02 14:06:04 -0700 | [diff] [blame] | 381 | pfn = page_to_boot_pfn(pages); |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 382 | epfn = pfn + count; |
| 383 | addr = pfn << PAGE_SHIFT; |
| 384 | eaddr = epfn << PAGE_SHIFT; |
| 385 | if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) || |
| 386 | kimage_is_destination_range(image, addr, eaddr)) { |
| 387 | list_add(&pages->lru, &extra_pages); |
| 388 | pages = NULL; |
| 389 | } |
| 390 | } while (!pages); |
| 391 | |
| 392 | if (pages) { |
| 393 | /* Remember the allocated page... */ |
| 394 | list_add(&pages->lru, &image->control_pages); |
| 395 | |
| 396 | /* Because the page is already in it's destination |
| 397 | * location we will never allocate another page at |
| 398 | * that address. Therefore kimage_alloc_pages |
| 399 | * will not return it (again) and we don't need |
| 400 | * to give it an entry in image->segment[]. |
| 401 | */ |
| 402 | } |
| 403 | /* Deal with the destination pages I have inadvertently allocated. |
| 404 | * |
| 405 | * Ideally I would convert multi-page allocations into single |
| 406 | * page allocations, and add everything to image->dest_pages. |
| 407 | * |
| 408 | * For now it is simpler to just free the pages. |
| 409 | */ |
| 410 | kimage_free_page_list(&extra_pages); |
| 411 | |
| 412 | return pages; |
| 413 | } |
| 414 | |
| 415 | static struct page *kimage_alloc_crash_control_pages(struct kimage *image, |
| 416 | unsigned int order) |
| 417 | { |
| 418 | /* Control pages are special, they are the intermediaries |
| 419 | * that are needed while we copy the rest of the pages |
| 420 | * to their final resting place. As such they must |
| 421 | * not conflict with either the destination addresses |
| 422 | * or memory the kernel is already using. |
| 423 | * |
| 424 | * Control pages are also the only pags we must allocate |
| 425 | * when loading a crash kernel. All of the other pages |
| 426 | * are specified by the segments and we just memcpy |
| 427 | * into them directly. |
| 428 | * |
| 429 | * The only case where we really need more than one of |
| 430 | * these are for architectures where we cannot disable |
| 431 | * the MMU and must instead generate an identity mapped |
| 432 | * page table for all of the memory. |
| 433 | * |
| 434 | * Given the low demand this implements a very simple |
| 435 | * allocator that finds the first hole of the appropriate |
| 436 | * size in the reserved memory region, and allocates all |
| 437 | * of the memory up to and including the hole. |
| 438 | */ |
| 439 | unsigned long hole_start, hole_end, size; |
| 440 | struct page *pages; |
| 441 | |
| 442 | pages = NULL; |
| 443 | size = (1 << order) << PAGE_SHIFT; |
| 444 | hole_start = (image->control_page + (size - 1)) & ~(size - 1); |
| 445 | hole_end = hole_start + size - 1; |
| 446 | while (hole_end <= crashk_res.end) { |
| 447 | unsigned long i; |
| 448 | |
zhong jiang | 8e53c07 | 2016-12-14 15:04:23 -0800 | [diff] [blame] | 449 | cond_resched(); |
| 450 | |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 451 | if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT) |
| 452 | break; |
| 453 | /* See if I overlap any of the segments */ |
| 454 | for (i = 0; i < image->nr_segments; i++) { |
| 455 | unsigned long mstart, mend; |
| 456 | |
| 457 | mstart = image->segment[i].mem; |
| 458 | mend = mstart + image->segment[i].memsz - 1; |
| 459 | if ((hole_end >= mstart) && (hole_start <= mend)) { |
| 460 | /* Advance the hole to the end of the segment */ |
| 461 | hole_start = (mend + (size - 1)) & ~(size - 1); |
| 462 | hole_end = hole_start + size - 1; |
| 463 | break; |
| 464 | } |
| 465 | } |
| 466 | /* If I don't overlap any segments I have found my hole! */ |
| 467 | if (i == image->nr_segments) { |
| 468 | pages = pfn_to_page(hole_start >> PAGE_SHIFT); |
Minfei Huang | 04e9949 | 2015-09-09 15:38:58 -0700 | [diff] [blame] | 469 | image->control_page = hole_end; |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 470 | break; |
| 471 | } |
| 472 | } |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 473 | |
Lianbo Jiang | 9cf38d5 | 2018-09-30 11:10:31 +0800 | [diff] [blame] | 474 | /* Ensure that these pages are decrypted if SME is enabled. */ |
| 475 | if (pages) |
| 476 | arch_kexec_post_alloc_pages(page_address(pages), 1 << order, 0); |
| 477 | |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 478 | return pages; |
| 479 | } |
| 480 | |
| 481 | |
| 482 | struct page *kimage_alloc_control_pages(struct kimage *image, |
| 483 | unsigned int order) |
| 484 | { |
| 485 | struct page *pages = NULL; |
| 486 | |
| 487 | switch (image->type) { |
| 488 | case KEXEC_TYPE_DEFAULT: |
| 489 | pages = kimage_alloc_normal_control_pages(image, order); |
| 490 | break; |
| 491 | case KEXEC_TYPE_CRASH: |
| 492 | pages = kimage_alloc_crash_control_pages(image, order); |
| 493 | break; |
| 494 | } |
| 495 | |
| 496 | return pages; |
| 497 | } |
| 498 | |
Xunlei Pang | 1229384 | 2017-07-12 14:33:21 -0700 | [diff] [blame] | 499 | int kimage_crash_copy_vmcoreinfo(struct kimage *image) |
| 500 | { |
| 501 | struct page *vmcoreinfo_page; |
| 502 | void *safecopy; |
| 503 | |
| 504 | if (image->type != KEXEC_TYPE_CRASH) |
| 505 | return 0; |
| 506 | |
| 507 | /* |
| 508 | * For kdump, allocate one vmcoreinfo safe copy from the |
| 509 | * crash memory. as we have arch_kexec_protect_crashkres() |
| 510 | * after kexec syscall, we naturally protect it from write |
| 511 | * (even read) access under kernel direct mapping. But on |
| 512 | * the other hand, we still need to operate it when crash |
| 513 | * happens to generate vmcoreinfo note, hereby we rely on |
| 514 | * vmap for this purpose. |
| 515 | */ |
| 516 | vmcoreinfo_page = kimage_alloc_control_pages(image, 0); |
| 517 | if (!vmcoreinfo_page) { |
| 518 | pr_warn("Could not allocate vmcoreinfo buffer\n"); |
| 519 | return -ENOMEM; |
| 520 | } |
| 521 | safecopy = vmap(&vmcoreinfo_page, 1, VM_MAP, PAGE_KERNEL); |
| 522 | if (!safecopy) { |
| 523 | pr_warn("Could not vmap vmcoreinfo buffer\n"); |
| 524 | return -ENOMEM; |
| 525 | } |
| 526 | |
| 527 | image->vmcoreinfo_data_copy = safecopy; |
| 528 | crash_update_vmcoreinfo_safecopy(safecopy); |
| 529 | |
| 530 | return 0; |
| 531 | } |
| 532 | |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 533 | static int kimage_add_entry(struct kimage *image, kimage_entry_t entry) |
| 534 | { |
| 535 | if (*image->entry != 0) |
| 536 | image->entry++; |
| 537 | |
| 538 | if (image->entry == image->last_entry) { |
| 539 | kimage_entry_t *ind_page; |
| 540 | struct page *page; |
| 541 | |
| 542 | page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST); |
| 543 | if (!page) |
| 544 | return -ENOMEM; |
| 545 | |
| 546 | ind_page = page_address(page); |
Russell King | 43546d8 | 2016-08-02 14:06:04 -0700 | [diff] [blame] | 547 | *image->entry = virt_to_boot_phys(ind_page) | IND_INDIRECTION; |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 548 | image->entry = ind_page; |
| 549 | image->last_entry = ind_page + |
| 550 | ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1); |
| 551 | } |
| 552 | *image->entry = entry; |
| 553 | image->entry++; |
| 554 | *image->entry = 0; |
| 555 | |
| 556 | return 0; |
| 557 | } |
| 558 | |
| 559 | static int kimage_set_destination(struct kimage *image, |
| 560 | unsigned long destination) |
| 561 | { |
| 562 | int result; |
| 563 | |
| 564 | destination &= PAGE_MASK; |
| 565 | result = kimage_add_entry(image, destination | IND_DESTINATION); |
| 566 | |
| 567 | return result; |
| 568 | } |
| 569 | |
| 570 | |
| 571 | static int kimage_add_page(struct kimage *image, unsigned long page) |
| 572 | { |
| 573 | int result; |
| 574 | |
| 575 | page &= PAGE_MASK; |
| 576 | result = kimage_add_entry(image, page | IND_SOURCE); |
| 577 | |
| 578 | return result; |
| 579 | } |
| 580 | |
| 581 | |
| 582 | static void kimage_free_extra_pages(struct kimage *image) |
| 583 | { |
| 584 | /* Walk through and free any extra destination pages I may have */ |
| 585 | kimage_free_page_list(&image->dest_pages); |
| 586 | |
| 587 | /* Walk through and free any unusable pages I have cached */ |
| 588 | kimage_free_page_list(&image->unusable_pages); |
| 589 | |
| 590 | } |
| 591 | void kimage_terminate(struct kimage *image) |
| 592 | { |
| 593 | if (*image->entry != 0) |
| 594 | image->entry++; |
| 595 | |
| 596 | *image->entry = IND_DONE; |
| 597 | } |
| 598 | |
| 599 | #define for_each_kimage_entry(image, ptr, entry) \ |
| 600 | for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \ |
| 601 | ptr = (entry & IND_INDIRECTION) ? \ |
Russell King | 43546d8 | 2016-08-02 14:06:04 -0700 | [diff] [blame] | 602 | boot_phys_to_virt((entry & PAGE_MASK)) : ptr + 1) |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 603 | |
| 604 | static void kimage_free_entry(kimage_entry_t entry) |
| 605 | { |
| 606 | struct page *page; |
| 607 | |
Russell King | 43546d8 | 2016-08-02 14:06:04 -0700 | [diff] [blame] | 608 | page = boot_pfn_to_page(entry >> PAGE_SHIFT); |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 609 | kimage_free_pages(page); |
| 610 | } |
| 611 | |
| 612 | void kimage_free(struct kimage *image) |
| 613 | { |
| 614 | kimage_entry_t *ptr, entry; |
| 615 | kimage_entry_t ind = 0; |
| 616 | |
| 617 | if (!image) |
| 618 | return; |
| 619 | |
Xunlei Pang | 1229384 | 2017-07-12 14:33:21 -0700 | [diff] [blame] | 620 | if (image->vmcoreinfo_data_copy) { |
| 621 | crash_update_vmcoreinfo_safecopy(NULL); |
| 622 | vunmap(image->vmcoreinfo_data_copy); |
| 623 | } |
| 624 | |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 625 | kimage_free_extra_pages(image); |
| 626 | for_each_kimage_entry(image, ptr, entry) { |
| 627 | if (entry & IND_INDIRECTION) { |
| 628 | /* Free the previous indirection page */ |
| 629 | if (ind & IND_INDIRECTION) |
| 630 | kimage_free_entry(ind); |
| 631 | /* Save this indirection page until we are |
| 632 | * done with it. |
| 633 | */ |
| 634 | ind = entry; |
| 635 | } else if (entry & IND_SOURCE) |
| 636 | kimage_free_entry(entry); |
| 637 | } |
| 638 | /* Free the final indirection page */ |
| 639 | if (ind & IND_INDIRECTION) |
| 640 | kimage_free_entry(ind); |
| 641 | |
| 642 | /* Handle any machine specific cleanup */ |
| 643 | machine_kexec_cleanup(image); |
| 644 | |
| 645 | /* Free the kexec control pages... */ |
| 646 | kimage_free_page_list(&image->control_pages); |
| 647 | |
| 648 | /* |
| 649 | * Free up any temporary buffers allocated. This might hit if |
| 650 | * error occurred much later after buffer allocation. |
| 651 | */ |
| 652 | if (image->file_mode) |
| 653 | kimage_file_post_load_cleanup(image); |
| 654 | |
| 655 | kfree(image); |
| 656 | } |
| 657 | |
| 658 | static kimage_entry_t *kimage_dst_used(struct kimage *image, |
| 659 | unsigned long page) |
| 660 | { |
| 661 | kimage_entry_t *ptr, entry; |
| 662 | unsigned long destination = 0; |
| 663 | |
| 664 | for_each_kimage_entry(image, ptr, entry) { |
| 665 | if (entry & IND_DESTINATION) |
| 666 | destination = entry & PAGE_MASK; |
| 667 | else if (entry & IND_SOURCE) { |
| 668 | if (page == destination) |
| 669 | return ptr; |
| 670 | destination += PAGE_SIZE; |
| 671 | } |
| 672 | } |
| 673 | |
| 674 | return NULL; |
| 675 | } |
| 676 | |
| 677 | static struct page *kimage_alloc_page(struct kimage *image, |
| 678 | gfp_t gfp_mask, |
| 679 | unsigned long destination) |
| 680 | { |
| 681 | /* |
| 682 | * Here we implement safeguards to ensure that a source page |
| 683 | * is not copied to its destination page before the data on |
| 684 | * the destination page is no longer useful. |
| 685 | * |
| 686 | * To do this we maintain the invariant that a source page is |
| 687 | * either its own destination page, or it is not a |
| 688 | * destination page at all. |
| 689 | * |
| 690 | * That is slightly stronger than required, but the proof |
| 691 | * that no problems will not occur is trivial, and the |
| 692 | * implementation is simply to verify. |
| 693 | * |
| 694 | * When allocating all pages normally this algorithm will run |
| 695 | * in O(N) time, but in the worst case it will run in O(N^2) |
| 696 | * time. If the runtime is a problem the data structures can |
| 697 | * be fixed. |
| 698 | */ |
| 699 | struct page *page; |
| 700 | unsigned long addr; |
| 701 | |
| 702 | /* |
| 703 | * Walk through the list of destination pages, and see if I |
| 704 | * have a match. |
| 705 | */ |
| 706 | list_for_each_entry(page, &image->dest_pages, lru) { |
Russell King | 43546d8 | 2016-08-02 14:06:04 -0700 | [diff] [blame] | 707 | addr = page_to_boot_pfn(page) << PAGE_SHIFT; |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 708 | if (addr == destination) { |
| 709 | list_del(&page->lru); |
| 710 | return page; |
| 711 | } |
| 712 | } |
| 713 | page = NULL; |
| 714 | while (1) { |
| 715 | kimage_entry_t *old; |
| 716 | |
| 717 | /* Allocate a page, if we run out of memory give up */ |
| 718 | page = kimage_alloc_pages(gfp_mask, 0); |
| 719 | if (!page) |
| 720 | return NULL; |
| 721 | /* If the page cannot be used file it away */ |
Russell King | 43546d8 | 2016-08-02 14:06:04 -0700 | [diff] [blame] | 722 | if (page_to_boot_pfn(page) > |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 723 | (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) { |
| 724 | list_add(&page->lru, &image->unusable_pages); |
| 725 | continue; |
| 726 | } |
Russell King | 43546d8 | 2016-08-02 14:06:04 -0700 | [diff] [blame] | 727 | addr = page_to_boot_pfn(page) << PAGE_SHIFT; |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 728 | |
| 729 | /* If it is the destination page we want use it */ |
| 730 | if (addr == destination) |
| 731 | break; |
| 732 | |
| 733 | /* If the page is not a destination page use it */ |
| 734 | if (!kimage_is_destination_range(image, addr, |
| 735 | addr + PAGE_SIZE)) |
| 736 | break; |
| 737 | |
| 738 | /* |
| 739 | * I know that the page is someones destination page. |
| 740 | * See if there is already a source page for this |
| 741 | * destination page. And if so swap the source pages. |
| 742 | */ |
| 743 | old = kimage_dst_used(image, addr); |
| 744 | if (old) { |
| 745 | /* If so move it */ |
| 746 | unsigned long old_addr; |
| 747 | struct page *old_page; |
| 748 | |
| 749 | old_addr = *old & PAGE_MASK; |
Russell King | 43546d8 | 2016-08-02 14:06:04 -0700 | [diff] [blame] | 750 | old_page = boot_pfn_to_page(old_addr >> PAGE_SHIFT); |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 751 | copy_highpage(page, old_page); |
| 752 | *old = addr | (*old & ~PAGE_MASK); |
| 753 | |
| 754 | /* The old page I have found cannot be a |
| 755 | * destination page, so return it if it's |
| 756 | * gfp_flags honor the ones passed in. |
| 757 | */ |
| 758 | if (!(gfp_mask & __GFP_HIGHMEM) && |
| 759 | PageHighMem(old_page)) { |
| 760 | kimage_free_pages(old_page); |
| 761 | continue; |
| 762 | } |
| 763 | addr = old_addr; |
| 764 | page = old_page; |
| 765 | break; |
| 766 | } |
| 767 | /* Place the page on the destination list, to be used later */ |
| 768 | list_add(&page->lru, &image->dest_pages); |
| 769 | } |
| 770 | |
| 771 | return page; |
| 772 | } |
| 773 | |
| 774 | static int kimage_load_normal_segment(struct kimage *image, |
| 775 | struct kexec_segment *segment) |
| 776 | { |
| 777 | unsigned long maddr; |
| 778 | size_t ubytes, mbytes; |
| 779 | int result; |
| 780 | unsigned char __user *buf = NULL; |
| 781 | unsigned char *kbuf = NULL; |
| 782 | |
| 783 | result = 0; |
| 784 | if (image->file_mode) |
| 785 | kbuf = segment->kbuf; |
| 786 | else |
| 787 | buf = segment->buf; |
| 788 | ubytes = segment->bufsz; |
| 789 | mbytes = segment->memsz; |
| 790 | maddr = segment->mem; |
| 791 | |
| 792 | result = kimage_set_destination(image, maddr); |
| 793 | if (result < 0) |
| 794 | goto out; |
| 795 | |
| 796 | while (mbytes) { |
| 797 | struct page *page; |
| 798 | char *ptr; |
| 799 | size_t uchunk, mchunk; |
| 800 | |
| 801 | page = kimage_alloc_page(image, GFP_HIGHUSER, maddr); |
| 802 | if (!page) { |
| 803 | result = -ENOMEM; |
| 804 | goto out; |
| 805 | } |
Russell King | 43546d8 | 2016-08-02 14:06:04 -0700 | [diff] [blame] | 806 | result = kimage_add_page(image, page_to_boot_pfn(page) |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 807 | << PAGE_SHIFT); |
| 808 | if (result < 0) |
| 809 | goto out; |
| 810 | |
| 811 | ptr = kmap(page); |
| 812 | /* Start with a clear page */ |
| 813 | clear_page(ptr); |
| 814 | ptr += maddr & ~PAGE_MASK; |
| 815 | mchunk = min_t(size_t, mbytes, |
| 816 | PAGE_SIZE - (maddr & ~PAGE_MASK)); |
| 817 | uchunk = min(ubytes, mchunk); |
| 818 | |
| 819 | /* For file based kexec, source pages are in kernel memory */ |
| 820 | if (image->file_mode) |
| 821 | memcpy(ptr, kbuf, uchunk); |
| 822 | else |
| 823 | result = copy_from_user(ptr, buf, uchunk); |
| 824 | kunmap(page); |
| 825 | if (result) { |
| 826 | result = -EFAULT; |
| 827 | goto out; |
| 828 | } |
| 829 | ubytes -= uchunk; |
| 830 | maddr += mchunk; |
| 831 | if (image->file_mode) |
| 832 | kbuf += mchunk; |
| 833 | else |
| 834 | buf += mchunk; |
| 835 | mbytes -= mchunk; |
Jarrett Farnitano | a8311f6 | 2018-06-14 15:26:31 -0700 | [diff] [blame] | 836 | |
| 837 | cond_resched(); |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 838 | } |
| 839 | out: |
| 840 | return result; |
| 841 | } |
| 842 | |
| 843 | static int kimage_load_crash_segment(struct kimage *image, |
| 844 | struct kexec_segment *segment) |
| 845 | { |
| 846 | /* For crash dumps kernels we simply copy the data from |
| 847 | * user space to it's destination. |
| 848 | * We do things a page at a time for the sake of kmap. |
| 849 | */ |
| 850 | unsigned long maddr; |
| 851 | size_t ubytes, mbytes; |
| 852 | int result; |
| 853 | unsigned char __user *buf = NULL; |
| 854 | unsigned char *kbuf = NULL; |
| 855 | |
| 856 | result = 0; |
| 857 | if (image->file_mode) |
| 858 | kbuf = segment->kbuf; |
| 859 | else |
| 860 | buf = segment->buf; |
| 861 | ubytes = segment->bufsz; |
| 862 | mbytes = segment->memsz; |
| 863 | maddr = segment->mem; |
| 864 | while (mbytes) { |
| 865 | struct page *page; |
| 866 | char *ptr; |
| 867 | size_t uchunk, mchunk; |
| 868 | |
Russell King | 43546d8 | 2016-08-02 14:06:04 -0700 | [diff] [blame] | 869 | page = boot_pfn_to_page(maddr >> PAGE_SHIFT); |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 870 | if (!page) { |
| 871 | result = -ENOMEM; |
| 872 | goto out; |
| 873 | } |
Lianbo Jiang | 9cf38d5 | 2018-09-30 11:10:31 +0800 | [diff] [blame] | 874 | arch_kexec_post_alloc_pages(page_address(page), 1, 0); |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 875 | ptr = kmap(page); |
| 876 | ptr += maddr & ~PAGE_MASK; |
| 877 | mchunk = min_t(size_t, mbytes, |
| 878 | PAGE_SIZE - (maddr & ~PAGE_MASK)); |
| 879 | uchunk = min(ubytes, mchunk); |
| 880 | if (mchunk > uchunk) { |
| 881 | /* Zero the trailing part of the page */ |
| 882 | memset(ptr + uchunk, 0, mchunk - uchunk); |
| 883 | } |
| 884 | |
| 885 | /* For file based kexec, source pages are in kernel memory */ |
| 886 | if (image->file_mode) |
| 887 | memcpy(ptr, kbuf, uchunk); |
| 888 | else |
| 889 | result = copy_from_user(ptr, buf, uchunk); |
| 890 | kexec_flush_icache_page(page); |
| 891 | kunmap(page); |
Lianbo Jiang | 9cf38d5 | 2018-09-30 11:10:31 +0800 | [diff] [blame] | 892 | arch_kexec_pre_free_pages(page_address(page), 1); |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 893 | if (result) { |
| 894 | result = -EFAULT; |
| 895 | goto out; |
| 896 | } |
| 897 | ubytes -= uchunk; |
| 898 | maddr += mchunk; |
| 899 | if (image->file_mode) |
| 900 | kbuf += mchunk; |
| 901 | else |
| 902 | buf += mchunk; |
| 903 | mbytes -= mchunk; |
Jarrett Farnitano | a8311f6 | 2018-06-14 15:26:31 -0700 | [diff] [blame] | 904 | |
| 905 | cond_resched(); |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 906 | } |
| 907 | out: |
| 908 | return result; |
| 909 | } |
| 910 | |
| 911 | int kimage_load_segment(struct kimage *image, |
| 912 | struct kexec_segment *segment) |
| 913 | { |
| 914 | int result = -ENOMEM; |
| 915 | |
| 916 | switch (image->type) { |
| 917 | case KEXEC_TYPE_DEFAULT: |
| 918 | result = kimage_load_normal_segment(image, segment); |
| 919 | break; |
| 920 | case KEXEC_TYPE_CRASH: |
| 921 | result = kimage_load_crash_segment(image, segment); |
| 922 | break; |
| 923 | } |
| 924 | |
| 925 | return result; |
| 926 | } |
| 927 | |
| 928 | struct kimage *kexec_image; |
| 929 | struct kimage *kexec_crash_image; |
| 930 | int kexec_load_disabled; |
| 931 | |
Hidehiro Kawai | 7bbee5c | 2015-12-14 11:19:11 +0100 | [diff] [blame] | 932 | /* |
| 933 | * No panic_cpu check version of crash_kexec(). This function is called |
| 934 | * only when panic_cpu holds the current CPU number; this is the only CPU |
| 935 | * which processes crash_kexec routines. |
| 936 | */ |
Josh Poimboeuf | c207aee | 2017-06-28 10:11:06 -0500 | [diff] [blame] | 937 | void __noclone __crash_kexec(struct pt_regs *regs) |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 938 | { |
| 939 | /* Take the kexec_mutex here to prevent sys_kexec_load |
| 940 | * running on one cpu from replacing the crash kernel |
| 941 | * we are using after a panic on a different cpu. |
| 942 | * |
| 943 | * If the crash kernel was not located in a fixed area |
| 944 | * of memory the xchg(&kexec_crash_image) would be |
| 945 | * sufficient. But since I reuse the memory... |
| 946 | */ |
| 947 | if (mutex_trylock(&kexec_mutex)) { |
| 948 | if (kexec_crash_image) { |
| 949 | struct pt_regs fixed_regs; |
| 950 | |
| 951 | crash_setup_regs(&fixed_regs, regs); |
| 952 | crash_save_vmcoreinfo(); |
| 953 | machine_crash_shutdown(&fixed_regs); |
| 954 | machine_kexec(kexec_crash_image); |
| 955 | } |
| 956 | mutex_unlock(&kexec_mutex); |
| 957 | } |
| 958 | } |
Josh Poimboeuf | c207aee | 2017-06-28 10:11:06 -0500 | [diff] [blame] | 959 | STACK_FRAME_NON_STANDARD(__crash_kexec); |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 960 | |
Hidehiro Kawai | 7bbee5c | 2015-12-14 11:19:11 +0100 | [diff] [blame] | 961 | void crash_kexec(struct pt_regs *regs) |
| 962 | { |
| 963 | int old_cpu, this_cpu; |
| 964 | |
| 965 | /* |
| 966 | * Only one CPU is allowed to execute the crash_kexec() code as with |
| 967 | * panic(). Otherwise parallel calls of panic() and crash_kexec() |
| 968 | * may stop each other. To exclude them, we use panic_cpu here too. |
| 969 | */ |
| 970 | this_cpu = raw_smp_processor_id(); |
| 971 | old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu); |
| 972 | if (old_cpu == PANIC_CPU_INVALID) { |
| 973 | /* This is the 1st CPU which comes here, so go ahead. */ |
Sergey Senozhatsky | f92bac3 | 2016-12-27 23:16:05 +0900 | [diff] [blame] | 974 | printk_safe_flush_on_panic(); |
Hidehiro Kawai | 7bbee5c | 2015-12-14 11:19:11 +0100 | [diff] [blame] | 975 | __crash_kexec(regs); |
| 976 | |
| 977 | /* |
| 978 | * Reset panic_cpu to allow another panic()/crash_kexec() |
| 979 | * call. |
| 980 | */ |
| 981 | atomic_set(&panic_cpu, PANIC_CPU_INVALID); |
| 982 | } |
| 983 | } |
| 984 | |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 985 | size_t crash_get_memory_size(void) |
| 986 | { |
| 987 | size_t size = 0; |
| 988 | |
| 989 | mutex_lock(&kexec_mutex); |
| 990 | if (crashk_res.end != crashk_res.start) |
| 991 | size = resource_size(&crashk_res); |
| 992 | mutex_unlock(&kexec_mutex); |
| 993 | return size; |
| 994 | } |
| 995 | |
| 996 | void __weak crash_free_reserved_phys_range(unsigned long begin, |
| 997 | unsigned long end) |
| 998 | { |
| 999 | unsigned long addr; |
| 1000 | |
| 1001 | for (addr = begin; addr < end; addr += PAGE_SIZE) |
Russell King | 43546d8 | 2016-08-02 14:06:04 -0700 | [diff] [blame] | 1002 | free_reserved_page(boot_pfn_to_page(addr >> PAGE_SHIFT)); |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 1003 | } |
| 1004 | |
| 1005 | int crash_shrink_memory(unsigned long new_size) |
| 1006 | { |
| 1007 | int ret = 0; |
| 1008 | unsigned long start, end; |
| 1009 | unsigned long old_size; |
| 1010 | struct resource *ram_res; |
| 1011 | |
| 1012 | mutex_lock(&kexec_mutex); |
| 1013 | |
| 1014 | if (kexec_crash_image) { |
| 1015 | ret = -ENOENT; |
| 1016 | goto unlock; |
| 1017 | } |
| 1018 | start = crashk_res.start; |
| 1019 | end = crashk_res.end; |
| 1020 | old_size = (end == 0) ? 0 : end - start + 1; |
| 1021 | if (new_size >= old_size) { |
| 1022 | ret = (new_size == old_size) ? 0 : -EINVAL; |
| 1023 | goto unlock; |
| 1024 | } |
| 1025 | |
| 1026 | ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL); |
| 1027 | if (!ram_res) { |
| 1028 | ret = -ENOMEM; |
| 1029 | goto unlock; |
| 1030 | } |
| 1031 | |
| 1032 | start = roundup(start, KEXEC_CRASH_MEM_ALIGN); |
| 1033 | end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN); |
| 1034 | |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 1035 | crash_free_reserved_phys_range(end, crashk_res.end); |
| 1036 | |
| 1037 | if ((start == end) && (crashk_res.parent != NULL)) |
| 1038 | release_resource(&crashk_res); |
| 1039 | |
| 1040 | ram_res->start = end; |
| 1041 | ram_res->end = crashk_res.end; |
Toshi Kani | 1a085d0 | 2016-01-26 21:57:23 +0100 | [diff] [blame] | 1042 | ram_res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM; |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 1043 | ram_res->name = "System RAM"; |
| 1044 | |
| 1045 | crashk_res.end = end - 1; |
| 1046 | |
| 1047 | insert_resource(&iomem_resource, ram_res); |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 1048 | |
| 1049 | unlock: |
| 1050 | mutex_unlock(&kexec_mutex); |
| 1051 | return ret; |
| 1052 | } |
| 1053 | |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 1054 | void crash_save_cpu(struct pt_regs *regs, int cpu) |
| 1055 | { |
| 1056 | struct elf_prstatus prstatus; |
| 1057 | u32 *buf; |
| 1058 | |
| 1059 | if ((cpu < 0) || (cpu >= nr_cpu_ids)) |
| 1060 | return; |
| 1061 | |
| 1062 | /* Using ELF notes here is opportunistic. |
| 1063 | * I need a well defined structure format |
| 1064 | * for the data I pass, and I need tags |
| 1065 | * on the data to indicate what information I have |
| 1066 | * squirrelled away. ELF notes happen to provide |
| 1067 | * all of that, so there is no need to invent something new. |
| 1068 | */ |
| 1069 | buf = (u32 *)per_cpu_ptr(crash_notes, cpu); |
| 1070 | if (!buf) |
| 1071 | return; |
| 1072 | memset(&prstatus, 0, sizeof(prstatus)); |
| 1073 | prstatus.pr_pid = current->pid; |
| 1074 | elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); |
| 1075 | buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, |
| 1076 | &prstatus, sizeof(prstatus)); |
| 1077 | final_note(buf); |
| 1078 | } |
| 1079 | |
| 1080 | static int __init crash_notes_memory_init(void) |
| 1081 | { |
| 1082 | /* Allocate memory for saving cpu registers. */ |
Baoquan He | bbb78b8 | 2015-09-09 15:39:00 -0700 | [diff] [blame] | 1083 | size_t size, align; |
| 1084 | |
| 1085 | /* |
| 1086 | * crash_notes could be allocated across 2 vmalloc pages when percpu |
| 1087 | * is vmalloc based . vmalloc doesn't guarantee 2 continuous vmalloc |
| 1088 | * pages are also on 2 continuous physical pages. In this case the |
| 1089 | * 2nd part of crash_notes in 2nd page could be lost since only the |
| 1090 | * starting address and size of crash_notes are exported through sysfs. |
| 1091 | * Here round up the size of crash_notes to the nearest power of two |
| 1092 | * and pass it to __alloc_percpu as align value. This can make sure |
| 1093 | * crash_notes is allocated inside one physical page. |
| 1094 | */ |
| 1095 | size = sizeof(note_buf_t); |
| 1096 | align = min(roundup_pow_of_two(sizeof(note_buf_t)), PAGE_SIZE); |
| 1097 | |
| 1098 | /* |
| 1099 | * Break compile if size is bigger than PAGE_SIZE since crash_notes |
| 1100 | * definitely will be in 2 pages with that. |
| 1101 | */ |
| 1102 | BUILD_BUG_ON(size > PAGE_SIZE); |
| 1103 | |
| 1104 | crash_notes = __alloc_percpu(size, align); |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 1105 | if (!crash_notes) { |
Minfei Huang | de90a6b | 2015-11-06 16:32:45 -0800 | [diff] [blame] | 1106 | pr_warn("Memory allocation for saving cpu register states failed\n"); |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 1107 | return -ENOMEM; |
| 1108 | } |
| 1109 | return 0; |
| 1110 | } |
| 1111 | subsys_initcall(crash_notes_memory_init); |
| 1112 | |
| 1113 | |
| 1114 | /* |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 1115 | * Move into place and start executing a preloaded standalone |
| 1116 | * executable. If nothing was preloaded return an error. |
| 1117 | */ |
| 1118 | int kernel_kexec(void) |
| 1119 | { |
| 1120 | int error = 0; |
| 1121 | |
| 1122 | if (!mutex_trylock(&kexec_mutex)) |
| 1123 | return -EBUSY; |
| 1124 | if (!kexec_image) { |
| 1125 | error = -EINVAL; |
| 1126 | goto Unlock; |
| 1127 | } |
| 1128 | |
| 1129 | #ifdef CONFIG_KEXEC_JUMP |
| 1130 | if (kexec_image->preserve_context) { |
| 1131 | lock_system_sleep(); |
| 1132 | pm_prepare_console(); |
| 1133 | error = freeze_processes(); |
| 1134 | if (error) { |
| 1135 | error = -EBUSY; |
| 1136 | goto Restore_console; |
| 1137 | } |
| 1138 | suspend_console(); |
| 1139 | error = dpm_suspend_start(PMSG_FREEZE); |
| 1140 | if (error) |
| 1141 | goto Resume_console; |
| 1142 | /* At this point, dpm_suspend_start() has been called, |
| 1143 | * but *not* dpm_suspend_end(). We *must* call |
| 1144 | * dpm_suspend_end() now. Otherwise, drivers for |
| 1145 | * some devices (e.g. interrupt controllers) become |
| 1146 | * desynchronized with the actual state of the |
| 1147 | * hardware at resume time, and evil weirdness ensues. |
| 1148 | */ |
| 1149 | error = dpm_suspend_end(PMSG_FREEZE); |
| 1150 | if (error) |
| 1151 | goto Resume_devices; |
| 1152 | error = disable_nonboot_cpus(); |
| 1153 | if (error) |
| 1154 | goto Enable_cpus; |
| 1155 | local_irq_disable(); |
| 1156 | error = syscore_suspend(); |
| 1157 | if (error) |
| 1158 | goto Enable_irqs; |
| 1159 | } else |
| 1160 | #endif |
| 1161 | { |
| 1162 | kexec_in_progress = true; |
| 1163 | kernel_restart_prepare(NULL); |
| 1164 | migrate_to_reboot_cpu(); |
| 1165 | |
| 1166 | /* |
| 1167 | * migrate_to_reboot_cpu() disables CPU hotplug assuming that |
| 1168 | * no further code needs to use CPU hotplug (which is true in |
| 1169 | * the reboot case). However, the kexec path depends on using |
| 1170 | * CPU hotplug again; so re-enable it here. |
| 1171 | */ |
| 1172 | cpu_hotplug_enable(); |
| 1173 | pr_emerg("Starting new kernel\n"); |
| 1174 | machine_shutdown(); |
| 1175 | } |
| 1176 | |
| 1177 | machine_kexec(kexec_image); |
| 1178 | |
| 1179 | #ifdef CONFIG_KEXEC_JUMP |
| 1180 | if (kexec_image->preserve_context) { |
| 1181 | syscore_resume(); |
| 1182 | Enable_irqs: |
| 1183 | local_irq_enable(); |
| 1184 | Enable_cpus: |
| 1185 | enable_nonboot_cpus(); |
| 1186 | dpm_resume_start(PMSG_RESTORE); |
| 1187 | Resume_devices: |
| 1188 | dpm_resume_end(PMSG_RESTORE); |
| 1189 | Resume_console: |
| 1190 | resume_console(); |
| 1191 | thaw_processes(); |
| 1192 | Restore_console: |
| 1193 | pm_restore_console(); |
| 1194 | unlock_system_sleep(); |
| 1195 | } |
| 1196 | #endif |
| 1197 | |
| 1198 | Unlock: |
| 1199 | mutex_unlock(&kexec_mutex); |
| 1200 | return error; |
| 1201 | } |
| 1202 | |
| 1203 | /* |
Xunlei Pang | 7a0058e | 2016-05-23 16:24:22 -0700 | [diff] [blame] | 1204 | * Protection mechanism for crashkernel reserved memory after |
| 1205 | * the kdump kernel is loaded. |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 1206 | * |
| 1207 | * Provide an empty default implementation here -- architecture |
| 1208 | * code may override this |
| 1209 | */ |
Xunlei Pang | 9b492cf | 2016-05-23 16:24:10 -0700 | [diff] [blame] | 1210 | void __weak arch_kexec_protect_crashkres(void) |
| 1211 | {} |
| 1212 | |
| 1213 | void __weak arch_kexec_unprotect_crashkres(void) |
| 1214 | {} |