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1da177e4 LT |
1 | /* |
2 | * linux/arch/x86_64/mm/init.c | |
3 | * | |
4 | * Copyright (C) 1995 Linus Torvalds | |
5 | * Copyright (C) 2000 Pavel Machek <pavel@suse.cz> | |
6 | * Copyright (C) 2002,2003 Andi Kleen <ak@suse.de> | |
7 | */ | |
8 | ||
9 | #include <linux/config.h> | |
10 | #include <linux/signal.h> | |
11 | #include <linux/sched.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/errno.h> | |
14 | #include <linux/string.h> | |
15 | #include <linux/types.h> | |
16 | #include <linux/ptrace.h> | |
17 | #include <linux/mman.h> | |
18 | #include <linux/mm.h> | |
19 | #include <linux/swap.h> | |
20 | #include <linux/smp.h> | |
21 | #include <linux/init.h> | |
22 | #include <linux/pagemap.h> | |
23 | #include <linux/bootmem.h> | |
24 | #include <linux/proc_fs.h> | |
25 | ||
26 | #include <asm/processor.h> | |
27 | #include <asm/system.h> | |
28 | #include <asm/uaccess.h> | |
29 | #include <asm/pgtable.h> | |
30 | #include <asm/pgalloc.h> | |
31 | #include <asm/dma.h> | |
32 | #include <asm/fixmap.h> | |
33 | #include <asm/e820.h> | |
34 | #include <asm/apic.h> | |
35 | #include <asm/tlb.h> | |
36 | #include <asm/mmu_context.h> | |
37 | #include <asm/proto.h> | |
38 | #include <asm/smp.h> | |
39 | ||
40 | #ifndef Dprintk | |
41 | #define Dprintk(x...) | |
42 | #endif | |
43 | ||
44 | #ifdef CONFIG_GART_IOMMU | |
45 | extern int swiotlb; | |
46 | #endif | |
47 | ||
48 | extern char _stext[]; | |
49 | ||
50 | DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); | |
51 | ||
52 | /* | |
53 | * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the | |
54 | * physical space so we can cache the place of the first one and move | |
55 | * around without checking the pgd every time. | |
56 | */ | |
57 | ||
58 | void show_mem(void) | |
59 | { | |
60 | int i, total = 0, reserved = 0; | |
61 | int shared = 0, cached = 0; | |
62 | pg_data_t *pgdat; | |
63 | struct page *page; | |
64 | ||
65 | printk("Mem-info:\n"); | |
66 | show_free_areas(); | |
67 | printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); | |
68 | ||
69 | for_each_pgdat(pgdat) { | |
70 | for (i = 0; i < pgdat->node_spanned_pages; ++i) { | |
71 | page = pfn_to_page(pgdat->node_start_pfn + i); | |
72 | total++; | |
73 | if (PageReserved(page)) | |
74 | reserved++; | |
75 | else if (PageSwapCache(page)) | |
76 | cached++; | |
77 | else if (page_count(page)) | |
78 | shared += page_count(page) - 1; | |
79 | } | |
80 | } | |
81 | printk("%d pages of RAM\n", total); | |
82 | printk("%d reserved pages\n",reserved); | |
83 | printk("%d pages shared\n",shared); | |
84 | printk("%d pages swap cached\n",cached); | |
85 | } | |
86 | ||
87 | /* References to section boundaries */ | |
88 | ||
89 | extern char _text, _etext, _edata, __bss_start, _end[]; | |
90 | extern char __init_begin, __init_end; | |
91 | ||
92 | int after_bootmem; | |
93 | ||
94 | static void *spp_getpage(void) | |
95 | { | |
96 | void *ptr; | |
97 | if (after_bootmem) | |
98 | ptr = (void *) get_zeroed_page(GFP_ATOMIC); | |
99 | else | |
100 | ptr = alloc_bootmem_pages(PAGE_SIZE); | |
101 | if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) | |
102 | panic("set_pte_phys: cannot allocate page data %s\n", after_bootmem?"after bootmem":""); | |
103 | ||
104 | Dprintk("spp_getpage %p\n", ptr); | |
105 | return ptr; | |
106 | } | |
107 | ||
108 | static void set_pte_phys(unsigned long vaddr, | |
109 | unsigned long phys, pgprot_t prot) | |
110 | { | |
111 | pgd_t *pgd; | |
112 | pud_t *pud; | |
113 | pmd_t *pmd; | |
114 | pte_t *pte, new_pte; | |
115 | ||
116 | Dprintk("set_pte_phys %lx to %lx\n", vaddr, phys); | |
117 | ||
118 | pgd = pgd_offset_k(vaddr); | |
119 | if (pgd_none(*pgd)) { | |
120 | printk("PGD FIXMAP MISSING, it should be setup in head.S!\n"); | |
121 | return; | |
122 | } | |
123 | pud = pud_offset(pgd, vaddr); | |
124 | if (pud_none(*pud)) { | |
125 | pmd = (pmd_t *) spp_getpage(); | |
126 | set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER)); | |
127 | if (pmd != pmd_offset(pud, 0)) { | |
128 | printk("PAGETABLE BUG #01! %p <-> %p\n", pmd, pmd_offset(pud,0)); | |
129 | return; | |
130 | } | |
131 | } | |
132 | pmd = pmd_offset(pud, vaddr); | |
133 | if (pmd_none(*pmd)) { | |
134 | pte = (pte_t *) spp_getpage(); | |
135 | set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER)); | |
136 | if (pte != pte_offset_kernel(pmd, 0)) { | |
137 | printk("PAGETABLE BUG #02!\n"); | |
138 | return; | |
139 | } | |
140 | } | |
141 | new_pte = pfn_pte(phys >> PAGE_SHIFT, prot); | |
142 | ||
143 | pte = pte_offset_kernel(pmd, vaddr); | |
144 | if (!pte_none(*pte) && | |
145 | pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask)) | |
146 | pte_ERROR(*pte); | |
147 | set_pte(pte, new_pte); | |
148 | ||
149 | /* | |
150 | * It's enough to flush this one mapping. | |
151 | * (PGE mappings get flushed as well) | |
152 | */ | |
153 | __flush_tlb_one(vaddr); | |
154 | } | |
155 | ||
156 | /* NOTE: this is meant to be run only at boot */ | |
157 | void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t prot) | |
158 | { | |
159 | unsigned long address = __fix_to_virt(idx); | |
160 | ||
161 | if (idx >= __end_of_fixed_addresses) { | |
162 | printk("Invalid __set_fixmap\n"); | |
163 | return; | |
164 | } | |
165 | set_pte_phys(address, phys, prot); | |
166 | } | |
167 | ||
168 | unsigned long __initdata table_start, table_end; | |
169 | ||
170 | extern pmd_t temp_boot_pmds[]; | |
171 | ||
172 | static struct temp_map { | |
173 | pmd_t *pmd; | |
174 | void *address; | |
175 | int allocated; | |
176 | } temp_mappings[] __initdata = { | |
177 | { &temp_boot_pmds[0], (void *)(40UL * 1024 * 1024) }, | |
178 | { &temp_boot_pmds[1], (void *)(42UL * 1024 * 1024) }, | |
179 | {} | |
180 | }; | |
181 | ||
182 | static __init void *alloc_low_page(int *index, unsigned long *phys) | |
183 | { | |
184 | struct temp_map *ti; | |
185 | int i; | |
186 | unsigned long pfn = table_end++, paddr; | |
187 | void *adr; | |
188 | ||
189 | if (pfn >= end_pfn) | |
190 | panic("alloc_low_page: ran out of memory"); | |
191 | for (i = 0; temp_mappings[i].allocated; i++) { | |
192 | if (!temp_mappings[i].pmd) | |
193 | panic("alloc_low_page: ran out of temp mappings"); | |
194 | } | |
195 | ti = &temp_mappings[i]; | |
196 | paddr = (pfn << PAGE_SHIFT) & PMD_MASK; | |
197 | set_pmd(ti->pmd, __pmd(paddr | _KERNPG_TABLE | _PAGE_PSE)); | |
198 | ti->allocated = 1; | |
199 | __flush_tlb(); | |
200 | adr = ti->address + ((pfn << PAGE_SHIFT) & ~PMD_MASK); | |
201 | *index = i; | |
202 | *phys = pfn * PAGE_SIZE; | |
203 | return adr; | |
204 | } | |
205 | ||
206 | static __init void unmap_low_page(int i) | |
207 | { | |
208 | struct temp_map *ti = &temp_mappings[i]; | |
209 | set_pmd(ti->pmd, __pmd(0)); | |
210 | ti->allocated = 0; | |
211 | } | |
212 | ||
213 | static void __init phys_pud_init(pud_t *pud, unsigned long address, unsigned long end) | |
214 | { | |
215 | long i, j; | |
216 | ||
217 | i = pud_index(address); | |
218 | pud = pud + i; | |
219 | for (; i < PTRS_PER_PUD; pud++, i++) { | |
220 | int map; | |
221 | unsigned long paddr, pmd_phys; | |
222 | pmd_t *pmd; | |
223 | ||
224 | paddr = address + i*PUD_SIZE; | |
225 | if (paddr >= end) { | |
226 | for (; i < PTRS_PER_PUD; i++, pud++) | |
227 | set_pud(pud, __pud(0)); | |
228 | break; | |
229 | } | |
230 | ||
231 | if (!e820_mapped(paddr, paddr+PUD_SIZE, 0)) { | |
232 | set_pud(pud, __pud(0)); | |
233 | continue; | |
234 | } | |
235 | ||
236 | pmd = alloc_low_page(&map, &pmd_phys); | |
237 | set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE)); | |
238 | for (j = 0; j < PTRS_PER_PMD; pmd++, j++, paddr += PMD_SIZE) { | |
239 | unsigned long pe; | |
240 | ||
241 | if (paddr >= end) { | |
242 | for (; j < PTRS_PER_PMD; j++, pmd++) | |
243 | set_pmd(pmd, __pmd(0)); | |
244 | break; | |
245 | } | |
246 | pe = _PAGE_NX|_PAGE_PSE | _KERNPG_TABLE | _PAGE_GLOBAL | paddr; | |
247 | pe &= __supported_pte_mask; | |
248 | set_pmd(pmd, __pmd(pe)); | |
249 | } | |
250 | unmap_low_page(map); | |
251 | } | |
252 | __flush_tlb(); | |
253 | } | |
254 | ||
255 | static void __init find_early_table_space(unsigned long end) | |
256 | { | |
257 | unsigned long puds, pmds, tables; | |
258 | ||
259 | puds = (end + PUD_SIZE - 1) >> PUD_SHIFT; | |
260 | pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT; | |
261 | tables = round_up(puds * sizeof(pud_t), PAGE_SIZE) + | |
262 | round_up(pmds * sizeof(pmd_t), PAGE_SIZE); | |
263 | ||
264 | table_start = find_e820_area(0x8000, __pa_symbol(&_text), tables); | |
265 | if (table_start == -1UL) | |
266 | panic("Cannot find space for the kernel page tables"); | |
267 | ||
268 | table_start >>= PAGE_SHIFT; | |
269 | table_end = table_start; | |
270 | } | |
271 | ||
272 | /* Setup the direct mapping of the physical memory at PAGE_OFFSET. | |
273 | This runs before bootmem is initialized and gets pages directly from the | |
274 | physical memory. To access them they are temporarily mapped. */ | |
275 | void __init init_memory_mapping(unsigned long start, unsigned long end) | |
276 | { | |
277 | unsigned long next; | |
278 | ||
279 | Dprintk("init_memory_mapping\n"); | |
280 | ||
281 | /* | |
282 | * Find space for the kernel direct mapping tables. | |
283 | * Later we should allocate these tables in the local node of the memory | |
284 | * mapped. Unfortunately this is done currently before the nodes are | |
285 | * discovered. | |
286 | */ | |
287 | find_early_table_space(end); | |
288 | ||
289 | start = (unsigned long)__va(start); | |
290 | end = (unsigned long)__va(end); | |
291 | ||
292 | for (; start < end; start = next) { | |
293 | int map; | |
294 | unsigned long pud_phys; | |
295 | pud_t *pud = alloc_low_page(&map, &pud_phys); | |
296 | next = start + PGDIR_SIZE; | |
297 | if (next > end) | |
298 | next = end; | |
299 | phys_pud_init(pud, __pa(start), __pa(next)); | |
300 | set_pgd(pgd_offset_k(start), mk_kernel_pgd(pud_phys)); | |
301 | unmap_low_page(map); | |
302 | } | |
303 | ||
304 | asm volatile("movq %%cr4,%0" : "=r" (mmu_cr4_features)); | |
305 | __flush_tlb_all(); | |
306 | early_printk("kernel direct mapping tables upto %lx @ %lx-%lx\n", end, | |
307 | table_start<<PAGE_SHIFT, | |
308 | table_end<<PAGE_SHIFT); | |
309 | } | |
310 | ||
311 | extern struct x8664_pda cpu_pda[NR_CPUS]; | |
312 | ||
313 | /* Assumes all CPUs still execute in init_mm */ | |
314 | void zap_low_mappings(void) | |
315 | { | |
316 | pgd_t *pgd = pgd_offset_k(0UL); | |
317 | pgd_clear(pgd); | |
318 | flush_tlb_all(); | |
319 | } | |
320 | ||
2b97690f | 321 | #ifndef CONFIG_NUMA |
1da177e4 LT |
322 | void __init paging_init(void) |
323 | { | |
324 | { | |
485761bd AK |
325 | unsigned long zones_size[MAX_NR_ZONES]; |
326 | unsigned long holes[MAX_NR_ZONES]; | |
1da177e4 LT |
327 | unsigned int max_dma; |
328 | ||
485761bd AK |
329 | memset(zones_size, 0, sizeof(zones_size)); |
330 | memset(holes, 0, sizeof(holes)); | |
331 | ||
1da177e4 LT |
332 | max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT; |
333 | ||
485761bd | 334 | if (end_pfn < max_dma) { |
1da177e4 | 335 | zones_size[ZONE_DMA] = end_pfn; |
485761bd AK |
336 | holes[ZONE_DMA] = e820_hole_size(0, end_pfn); |
337 | } else { | |
1da177e4 | 338 | zones_size[ZONE_DMA] = max_dma; |
485761bd | 339 | holes[ZONE_DMA] = e820_hole_size(0, max_dma); |
1da177e4 | 340 | zones_size[ZONE_NORMAL] = end_pfn - max_dma; |
485761bd | 341 | holes[ZONE_NORMAL] = e820_hole_size(max_dma, end_pfn); |
1da177e4 | 342 | } |
485761bd AK |
343 | free_area_init_node(0, NODE_DATA(0), zones_size, |
344 | __pa(PAGE_OFFSET) >> PAGE_SHIFT, holes); | |
1da177e4 LT |
345 | } |
346 | return; | |
347 | } | |
348 | #endif | |
349 | ||
350 | /* Unmap a kernel mapping if it exists. This is useful to avoid prefetches | |
351 | from the CPU leading to inconsistent cache lines. address and size | |
352 | must be aligned to 2MB boundaries. | |
353 | Does nothing when the mapping doesn't exist. */ | |
354 | void __init clear_kernel_mapping(unsigned long address, unsigned long size) | |
355 | { | |
356 | unsigned long end = address + size; | |
357 | ||
358 | BUG_ON(address & ~LARGE_PAGE_MASK); | |
359 | BUG_ON(size & ~LARGE_PAGE_MASK); | |
360 | ||
361 | for (; address < end; address += LARGE_PAGE_SIZE) { | |
362 | pgd_t *pgd = pgd_offset_k(address); | |
363 | pud_t *pud; | |
364 | pmd_t *pmd; | |
365 | if (pgd_none(*pgd)) | |
366 | continue; | |
367 | pud = pud_offset(pgd, address); | |
368 | if (pud_none(*pud)) | |
369 | continue; | |
370 | pmd = pmd_offset(pud, address); | |
371 | if (!pmd || pmd_none(*pmd)) | |
372 | continue; | |
373 | if (0 == (pmd_val(*pmd) & _PAGE_PSE)) { | |
374 | /* Could handle this, but it should not happen currently. */ | |
375 | printk(KERN_ERR | |
376 | "clear_kernel_mapping: mapping has been split. will leak memory\n"); | |
377 | pmd_ERROR(*pmd); | |
378 | } | |
379 | set_pmd(pmd, __pmd(0)); | |
380 | } | |
381 | __flush_tlb_all(); | |
382 | } | |
383 | ||
384 | static inline int page_is_ram (unsigned long pagenr) | |
385 | { | |
386 | int i; | |
387 | ||
388 | for (i = 0; i < e820.nr_map; i++) { | |
389 | unsigned long addr, end; | |
390 | ||
391 | if (e820.map[i].type != E820_RAM) /* not usable memory */ | |
392 | continue; | |
393 | /* | |
394 | * !!!FIXME!!! Some BIOSen report areas as RAM that | |
395 | * are not. Notably the 640->1Mb area. We need a sanity | |
396 | * check here. | |
397 | */ | |
398 | addr = (e820.map[i].addr+PAGE_SIZE-1) >> PAGE_SHIFT; | |
399 | end = (e820.map[i].addr+e820.map[i].size) >> PAGE_SHIFT; | |
400 | if ((pagenr >= addr) && (pagenr < end)) | |
401 | return 1; | |
402 | } | |
403 | return 0; | |
404 | } | |
405 | ||
1da177e4 LT |
406 | static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel, kcore_modules, |
407 | kcore_vsyscall; | |
408 | ||
409 | void __init mem_init(void) | |
410 | { | |
411 | int codesize, reservedpages, datasize, initsize; | |
412 | int tmp; | |
413 | ||
414 | #ifdef CONFIG_SWIOTLB | |
1da177e4 LT |
415 | if (!iommu_aperture && |
416 | (end_pfn >= 0xffffffff>>PAGE_SHIFT || force_iommu)) | |
417 | swiotlb = 1; | |
418 | if (swiotlb) | |
419 | swiotlb_init(); | |
420 | #endif | |
421 | ||
422 | /* How many end-of-memory variables you have, grandma! */ | |
423 | max_low_pfn = end_pfn; | |
424 | max_pfn = end_pfn; | |
425 | num_physpages = end_pfn; | |
426 | high_memory = (void *) __va(end_pfn * PAGE_SIZE); | |
427 | ||
428 | /* clear the zero-page */ | |
429 | memset(empty_zero_page, 0, PAGE_SIZE); | |
430 | ||
431 | reservedpages = 0; | |
432 | ||
433 | /* this will put all low memory onto the freelists */ | |
2b97690f | 434 | #ifdef CONFIG_NUMA |
1da177e4 LT |
435 | totalram_pages += numa_free_all_bootmem(); |
436 | tmp = 0; | |
437 | /* should count reserved pages here for all nodes */ | |
438 | #else | |
2b97690f MT |
439 | |
440 | #ifdef CONFIG_FLATMEM | |
1da177e4 LT |
441 | max_mapnr = end_pfn; |
442 | if (!mem_map) BUG(); | |
2b97690f | 443 | #endif |
1da177e4 LT |
444 | |
445 | totalram_pages += free_all_bootmem(); | |
446 | ||
447 | for (tmp = 0; tmp < end_pfn; tmp++) | |
448 | /* | |
449 | * Only count reserved RAM pages | |
450 | */ | |
451 | if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp))) | |
452 | reservedpages++; | |
453 | #endif | |
454 | ||
455 | after_bootmem = 1; | |
456 | ||
457 | codesize = (unsigned long) &_etext - (unsigned long) &_text; | |
458 | datasize = (unsigned long) &_edata - (unsigned long) &_etext; | |
459 | initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; | |
460 | ||
461 | /* Register memory areas for /proc/kcore */ | |
462 | kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); | |
463 | kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, | |
464 | VMALLOC_END-VMALLOC_START); | |
465 | kclist_add(&kcore_kernel, &_stext, _end - _stext); | |
466 | kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN); | |
467 | kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START, | |
468 | VSYSCALL_END - VSYSCALL_START); | |
469 | ||
470 | printk("Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init)\n", | |
471 | (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), | |
472 | end_pfn << (PAGE_SHIFT-10), | |
473 | codesize >> 10, | |
474 | reservedpages << (PAGE_SHIFT-10), | |
475 | datasize >> 10, | |
476 | initsize >> 10); | |
477 | ||
478 | /* | |
479 | * Subtle. SMP is doing its boot stuff late (because it has to | |
480 | * fork idle threads) - but it also needs low mappings for the | |
481 | * protected-mode entry to work. We zap these entries only after | |
482 | * the WP-bit has been tested. | |
483 | */ | |
484 | #ifndef CONFIG_SMP | |
485 | zap_low_mappings(); | |
486 | #endif | |
487 | } | |
488 | ||
489 | extern char __initdata_begin[], __initdata_end[]; | |
490 | ||
491 | void free_initmem(void) | |
492 | { | |
493 | unsigned long addr; | |
494 | ||
495 | addr = (unsigned long)(&__init_begin); | |
496 | for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) { | |
497 | ClearPageReserved(virt_to_page(addr)); | |
498 | set_page_count(virt_to_page(addr), 1); | |
499 | memset((void *)(addr & ~(PAGE_SIZE-1)), 0xcc, PAGE_SIZE); | |
500 | free_page(addr); | |
501 | totalram_pages++; | |
502 | } | |
503 | memset(__initdata_begin, 0xba, __initdata_end - __initdata_begin); | |
504 | printk ("Freeing unused kernel memory: %luk freed\n", (&__init_end - &__init_begin) >> 10); | |
505 | } | |
506 | ||
507 | #ifdef CONFIG_BLK_DEV_INITRD | |
508 | void free_initrd_mem(unsigned long start, unsigned long end) | |
509 | { | |
510 | if (start < (unsigned long)&_end) | |
511 | return; | |
512 | printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); | |
513 | for (; start < end; start += PAGE_SIZE) { | |
514 | ClearPageReserved(virt_to_page(start)); | |
515 | set_page_count(virt_to_page(start), 1); | |
516 | free_page(start); | |
517 | totalram_pages++; | |
518 | } | |
519 | } | |
520 | #endif | |
521 | ||
522 | void __init reserve_bootmem_generic(unsigned long phys, unsigned len) | |
523 | { | |
524 | /* Should check here against the e820 map to avoid double free */ | |
2b97690f | 525 | #ifdef CONFIG_NUMA |
1da177e4 LT |
526 | int nid = phys_to_nid(phys); |
527 | reserve_bootmem_node(NODE_DATA(nid), phys, len); | |
528 | #else | |
529 | reserve_bootmem(phys, len); | |
530 | #endif | |
531 | } | |
532 | ||
533 | int kern_addr_valid(unsigned long addr) | |
534 | { | |
535 | unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; | |
536 | pgd_t *pgd; | |
537 | pud_t *pud; | |
538 | pmd_t *pmd; | |
539 | pte_t *pte; | |
540 | ||
541 | if (above != 0 && above != -1UL) | |
542 | return 0; | |
543 | ||
544 | pgd = pgd_offset_k(addr); | |
545 | if (pgd_none(*pgd)) | |
546 | return 0; | |
547 | ||
548 | pud = pud_offset(pgd, addr); | |
549 | if (pud_none(*pud)) | |
550 | return 0; | |
551 | ||
552 | pmd = pmd_offset(pud, addr); | |
553 | if (pmd_none(*pmd)) | |
554 | return 0; | |
555 | if (pmd_large(*pmd)) | |
556 | return pfn_valid(pmd_pfn(*pmd)); | |
557 | ||
558 | pte = pte_offset_kernel(pmd, addr); | |
559 | if (pte_none(*pte)) | |
560 | return 0; | |
561 | return pfn_valid(pte_pfn(*pte)); | |
562 | } | |
563 | ||
564 | #ifdef CONFIG_SYSCTL | |
565 | #include <linux/sysctl.h> | |
566 | ||
567 | extern int exception_trace, page_fault_trace; | |
568 | ||
569 | static ctl_table debug_table2[] = { | |
570 | { 99, "exception-trace", &exception_trace, sizeof(int), 0644, NULL, | |
571 | proc_dointvec }, | |
572 | #ifdef CONFIG_CHECKING | |
573 | { 100, "page-fault-trace", &page_fault_trace, sizeof(int), 0644, NULL, | |
574 | proc_dointvec }, | |
575 | #endif | |
576 | { 0, } | |
577 | }; | |
578 | ||
579 | static ctl_table debug_root_table2[] = { | |
580 | { .ctl_name = CTL_DEBUG, .procname = "debug", .mode = 0555, | |
581 | .child = debug_table2 }, | |
582 | { 0 }, | |
583 | }; | |
584 | ||
585 | static __init int x8664_sysctl_init(void) | |
586 | { | |
587 | register_sysctl_table(debug_root_table2, 1); | |
588 | return 0; | |
589 | } | |
590 | __initcall(x8664_sysctl_init); | |
591 | #endif | |
592 | ||
1e014410 AK |
593 | /* A pseudo VMAs to allow ptrace access for the vsyscall page. This only |
594 | covers the 64bit vsyscall page now. 32bit has a real VMA now and does | |
595 | not need special handling anymore. */ | |
1da177e4 LT |
596 | |
597 | static struct vm_area_struct gate_vma = { | |
598 | .vm_start = VSYSCALL_START, | |
599 | .vm_end = VSYSCALL_END, | |
600 | .vm_page_prot = PAGE_READONLY | |
601 | }; | |
602 | ||
1da177e4 LT |
603 | struct vm_area_struct *get_gate_vma(struct task_struct *tsk) |
604 | { | |
605 | #ifdef CONFIG_IA32_EMULATION | |
1e014410 AK |
606 | if (test_tsk_thread_flag(tsk, TIF_IA32)) |
607 | return NULL; | |
1da177e4 LT |
608 | #endif |
609 | return &gate_vma; | |
610 | } | |
611 | ||
612 | int in_gate_area(struct task_struct *task, unsigned long addr) | |
613 | { | |
614 | struct vm_area_struct *vma = get_gate_vma(task); | |
1e014410 AK |
615 | if (!vma) |
616 | return 0; | |
1da177e4 LT |
617 | return (addr >= vma->vm_start) && (addr < vma->vm_end); |
618 | } | |
619 | ||
620 | /* Use this when you have no reliable task/vma, typically from interrupt | |
621 | * context. It is less reliable than using the task's vma and may give | |
622 | * false positives. | |
623 | */ | |
624 | int in_gate_area_no_task(unsigned long addr) | |
625 | { | |
1e014410 | 626 | return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END); |
1da177e4 | 627 | } |