1 /* 2 * linux/arch/arm/mm/init.c 3 * 4 * Copyright (C) 1995-2005 Russell King 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 #include <linux/kernel.h> 11 #include <linux/errno.h> 12 #include <linux/swap.h> 13 #include <linux/init.h> 14 #include <linux/mman.h> 15 #include <linux/sched/signal.h> 16 #include <linux/sched/task.h> 17 #include <linux/export.h> 18 #include <linux/nodemask.h> 19 #include <linux/initrd.h> 20 #include <linux/of_fdt.h> 21 #include <linux/highmem.h> 22 #include <linux/gfp.h> 23 #include <linux/memblock.h> 24 #include <linux/dma-contiguous.h> 25 #include <linux/sizes.h> 26 #include <linux/stop_machine.h> 27 28 #include <asm/cp15.h> 29 #include <asm/mach-types.h> 30 #include <asm/memblock.h> 31 #include <asm/memory.h> 32 #include <asm/prom.h> 33 #include <asm/sections.h> 34 #include <asm/setup.h> 35 #include <asm/system_info.h> 36 #include <asm/tlb.h> 37 #include <asm/fixmap.h> 38 #include <asm/ptdump.h> 39 40 #include <asm/mach/arch.h> 41 #include <asm/mach/map.h> 42 43 #include "mm.h" 44 45 #ifdef CONFIG_CPU_CP15_MMU 46 unsigned long __init __clear_cr(unsigned long mask) 47 { 48 cr_alignment = cr_alignment & ~mask; 49 return cr_alignment; 50 } 51 #endif 52 53 #ifdef CONFIG_BLK_DEV_INITRD 54 static int __init parse_tag_initrd(const struct tag *tag) 55 { 56 pr_warn("ATAG_INITRD is deprecated; " 57 "please update your bootloader.\n"); 58 phys_initrd_start = __virt_to_phys(tag->u.initrd.start); 59 phys_initrd_size = tag->u.initrd.size; 60 return 0; 61 } 62 63 __tagtable(ATAG_INITRD, parse_tag_initrd); 64 65 static int __init parse_tag_initrd2(const struct tag *tag) 66 { 67 phys_initrd_start = tag->u.initrd.start; 68 phys_initrd_size = tag->u.initrd.size; 69 return 0; 70 } 71 72 __tagtable(ATAG_INITRD2, parse_tag_initrd2); 73 #endif 74 75 static void __init find_limits(unsigned long *min, unsigned long *max_low, 76 unsigned long *max_high) 77 { 78 *max_low = PFN_DOWN(memblock_get_current_limit()); 79 *min = PFN_UP(memblock_start_of_DRAM()); 80 *max_high = PFN_DOWN(memblock_end_of_DRAM()); 81 } 82 83 #ifdef CONFIG_ZONE_DMA 84 85 phys_addr_t arm_dma_zone_size __read_mostly; 86 EXPORT_SYMBOL(arm_dma_zone_size); 87 88 /* 89 * The DMA mask corresponding to the maximum bus address allocatable 90 * using GFP_DMA. The default here places no restriction on DMA 91 * allocations. This must be the smallest DMA mask in the system, 92 * so a successful GFP_DMA allocation will always satisfy this. 93 */ 94 phys_addr_t arm_dma_limit; 95 unsigned long arm_dma_pfn_limit; 96 97 static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole, 98 unsigned long dma_size) 99 { 100 if (size[0] <= dma_size) 101 return; 102 103 size[ZONE_NORMAL] = size[0] - dma_size; 104 size[ZONE_DMA] = dma_size; 105 hole[ZONE_NORMAL] = hole[0]; 106 hole[ZONE_DMA] = 0; 107 } 108 #endif 109 110 void __init setup_dma_zone(const struct machine_desc *mdesc) 111 { 112 #ifdef CONFIG_ZONE_DMA 113 if (mdesc->dma_zone_size) { 114 arm_dma_zone_size = mdesc->dma_zone_size; 115 arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1; 116 } else 117 arm_dma_limit = 0xffffffff; 118 arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT; 119 #endif 120 } 121 122 static void __init zone_sizes_init(unsigned long min, unsigned long max_low, 123 unsigned long max_high) 124 { 125 unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES]; 126 struct memblock_region *reg; 127 128 /* 129 * initialise the zones. 130 */ 131 memset(zone_size, 0, sizeof(zone_size)); 132 133 /* 134 * The memory size has already been determined. If we need 135 * to do anything fancy with the allocation of this memory 136 * to the zones, now is the time to do it. 137 */ 138 zone_size[0] = max_low - min; 139 #ifdef CONFIG_HIGHMEM 140 zone_size[ZONE_HIGHMEM] = max_high - max_low; 141 #endif 142 143 /* 144 * Calculate the size of the holes. 145 * holes = node_size - sum(bank_sizes) 146 */ 147 memcpy(zhole_size, zone_size, sizeof(zhole_size)); 148 for_each_memblock(memory, reg) { 149 unsigned long start = memblock_region_memory_base_pfn(reg); 150 unsigned long end = memblock_region_memory_end_pfn(reg); 151 152 if (start < max_low) { 153 unsigned long low_end = min(end, max_low); 154 zhole_size[0] -= low_end - start; 155 } 156 #ifdef CONFIG_HIGHMEM 157 if (end > max_low) { 158 unsigned long high_start = max(start, max_low); 159 zhole_size[ZONE_HIGHMEM] -= end - high_start; 160 } 161 #endif 162 } 163 164 #ifdef CONFIG_ZONE_DMA 165 /* 166 * Adjust the sizes according to any special requirements for 167 * this machine type. 168 */ 169 if (arm_dma_zone_size) 170 arm_adjust_dma_zone(zone_size, zhole_size, 171 arm_dma_zone_size >> PAGE_SHIFT); 172 #endif 173 174 free_area_init_node(0, zone_size, min, zhole_size); 175 } 176 177 #ifdef CONFIG_HAVE_ARCH_PFN_VALID 178 int pfn_valid(unsigned long pfn) 179 { 180 return memblock_is_map_memory(__pfn_to_phys(pfn)); 181 } 182 EXPORT_SYMBOL(pfn_valid); 183 #endif 184 185 #ifndef CONFIG_SPARSEMEM 186 static void __init arm_memory_present(void) 187 { 188 } 189 #else 190 static void __init arm_memory_present(void) 191 { 192 struct memblock_region *reg; 193 194 for_each_memblock(memory, reg) 195 memory_present(0, memblock_region_memory_base_pfn(reg), 196 memblock_region_memory_end_pfn(reg)); 197 } 198 #endif 199 200 static bool arm_memblock_steal_permitted = true; 201 202 phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align) 203 { 204 phys_addr_t phys; 205 206 BUG_ON(!arm_memblock_steal_permitted); 207 208 phys = memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE); 209 memblock_free(phys, size); 210 memblock_remove(phys, size); 211 212 return phys; 213 } 214 215 static void __init arm_initrd_init(void) 216 { 217 #ifdef CONFIG_BLK_DEV_INITRD 218 phys_addr_t start; 219 unsigned long size; 220 221 initrd_start = initrd_end = 0; 222 223 if (!phys_initrd_size) 224 return; 225 226 /* 227 * Round the memory region to page boundaries as per free_initrd_mem() 228 * This allows us to detect whether the pages overlapping the initrd 229 * are in use, but more importantly, reserves the entire set of pages 230 * as we don't want these pages allocated for other purposes. 231 */ 232 start = round_down(phys_initrd_start, PAGE_SIZE); 233 size = phys_initrd_size + (phys_initrd_start - start); 234 size = round_up(size, PAGE_SIZE); 235 236 if (!memblock_is_region_memory(start, size)) { 237 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n", 238 (u64)start, size); 239 return; 240 } 241 242 if (memblock_is_region_reserved(start, size)) { 243 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n", 244 (u64)start, size); 245 return; 246 } 247 248 memblock_reserve(start, size); 249 250 /* Now convert initrd to virtual addresses */ 251 initrd_start = __phys_to_virt(phys_initrd_start); 252 initrd_end = initrd_start + phys_initrd_size; 253 #endif 254 } 255 256 void __init arm_memblock_init(const struct machine_desc *mdesc) 257 { 258 /* Register the kernel text, kernel data and initrd with memblock. */ 259 memblock_reserve(__pa(KERNEL_START), KERNEL_END - KERNEL_START); 260 261 arm_initrd_init(); 262 263 arm_mm_memblock_reserve(); 264 265 /* reserve any platform specific memblock areas */ 266 if (mdesc->reserve) 267 mdesc->reserve(); 268 269 early_init_fdt_reserve_self(); 270 early_init_fdt_scan_reserved_mem(); 271 272 /* reserve memory for DMA contiguous allocations */ 273 dma_contiguous_reserve(arm_dma_limit); 274 275 arm_memblock_steal_permitted = false; 276 memblock_dump_all(); 277 } 278 279 void __init bootmem_init(void) 280 { 281 unsigned long min, max_low, max_high; 282 283 memblock_allow_resize(); 284 max_low = max_high = 0; 285 286 find_limits(&min, &max_low, &max_high); 287 288 early_memtest((phys_addr_t)min << PAGE_SHIFT, 289 (phys_addr_t)max_low << PAGE_SHIFT); 290 291 /* 292 * Sparsemem tries to allocate bootmem in memory_present(), 293 * so must be done after the fixed reservations 294 */ 295 arm_memory_present(); 296 297 /* 298 * sparse_init() needs the bootmem allocator up and running. 299 */ 300 sparse_init(); 301 302 /* 303 * Now free the memory - free_area_init_node needs 304 * the sparse mem_map arrays initialized by sparse_init() 305 * for memmap_init_zone(), otherwise all PFNs are invalid. 306 */ 307 zone_sizes_init(min, max_low, max_high); 308 309 /* 310 * This doesn't seem to be used by the Linux memory manager any 311 * more, but is used by ll_rw_block. If we can get rid of it, we 312 * also get rid of some of the stuff above as well. 313 */ 314 min_low_pfn = min; 315 max_low_pfn = max_low; 316 max_pfn = max_high; 317 } 318 319 /* 320 * Poison init memory with an undefined instruction (ARM) or a branch to an 321 * undefined instruction (Thumb). 322 */ 323 static inline void poison_init_mem(void *s, size_t count) 324 { 325 u32 *p = (u32 *)s; 326 for (; count != 0; count -= 4) 327 *p++ = 0xe7fddef0; 328 } 329 330 static inline void 331 free_memmap(unsigned long start_pfn, unsigned long end_pfn) 332 { 333 struct page *start_pg, *end_pg; 334 phys_addr_t pg, pgend; 335 336 /* 337 * Convert start_pfn/end_pfn to a struct page pointer. 338 */ 339 start_pg = pfn_to_page(start_pfn - 1) + 1; 340 end_pg = pfn_to_page(end_pfn - 1) + 1; 341 342 /* 343 * Convert to physical addresses, and 344 * round start upwards and end downwards. 345 */ 346 pg = PAGE_ALIGN(__pa(start_pg)); 347 pgend = __pa(end_pg) & PAGE_MASK; 348 349 /* 350 * If there are free pages between these, 351 * free the section of the memmap array. 352 */ 353 if (pg < pgend) 354 memblock_free_early(pg, pgend - pg); 355 } 356 357 /* 358 * The mem_map array can get very big. Free the unused area of the memory map. 359 */ 360 static void __init free_unused_memmap(void) 361 { 362 unsigned long start, prev_end = 0; 363 struct memblock_region *reg; 364 365 /* 366 * This relies on each bank being in address order. 367 * The banks are sorted previously in bootmem_init(). 368 */ 369 for_each_memblock(memory, reg) { 370 start = memblock_region_memory_base_pfn(reg); 371 372 #ifdef CONFIG_SPARSEMEM 373 /* 374 * Take care not to free memmap entries that don't exist 375 * due to SPARSEMEM sections which aren't present. 376 */ 377 start = min(start, 378 ALIGN(prev_end, PAGES_PER_SECTION)); 379 #else 380 /* 381 * Align down here since the VM subsystem insists that the 382 * memmap entries are valid from the bank start aligned to 383 * MAX_ORDER_NR_PAGES. 384 */ 385 start = round_down(start, MAX_ORDER_NR_PAGES); 386 #endif 387 /* 388 * If we had a previous bank, and there is a space 389 * between the current bank and the previous, free it. 390 */ 391 if (prev_end && prev_end < start) 392 free_memmap(prev_end, start); 393 394 /* 395 * Align up here since the VM subsystem insists that the 396 * memmap entries are valid from the bank end aligned to 397 * MAX_ORDER_NR_PAGES. 398 */ 399 prev_end = ALIGN(memblock_region_memory_end_pfn(reg), 400 MAX_ORDER_NR_PAGES); 401 } 402 403 #ifdef CONFIG_SPARSEMEM 404 if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION)) 405 free_memmap(prev_end, 406 ALIGN(prev_end, PAGES_PER_SECTION)); 407 #endif 408 } 409 410 #ifdef CONFIG_HIGHMEM 411 static inline void free_area_high(unsigned long pfn, unsigned long end) 412 { 413 for (; pfn < end; pfn++) 414 free_highmem_page(pfn_to_page(pfn)); 415 } 416 #endif 417 418 static void __init free_highpages(void) 419 { 420 #ifdef CONFIG_HIGHMEM 421 unsigned long max_low = max_low_pfn; 422 struct memblock_region *mem, *res; 423 424 /* set highmem page free */ 425 for_each_memblock(memory, mem) { 426 unsigned long start = memblock_region_memory_base_pfn(mem); 427 unsigned long end = memblock_region_memory_end_pfn(mem); 428 429 /* Ignore complete lowmem entries */ 430 if (end <= max_low) 431 continue; 432 433 if (memblock_is_nomap(mem)) 434 continue; 435 436 /* Truncate partial highmem entries */ 437 if (start < max_low) 438 start = max_low; 439 440 /* Find and exclude any reserved regions */ 441 for_each_memblock(reserved, res) { 442 unsigned long res_start, res_end; 443 444 res_start = memblock_region_reserved_base_pfn(res); 445 res_end = memblock_region_reserved_end_pfn(res); 446 447 if (res_end < start) 448 continue; 449 if (res_start < start) 450 res_start = start; 451 if (res_start > end) 452 res_start = end; 453 if (res_end > end) 454 res_end = end; 455 if (res_start != start) 456 free_area_high(start, res_start); 457 start = res_end; 458 if (start == end) 459 break; 460 } 461 462 /* And now free anything which remains */ 463 if (start < end) 464 free_area_high(start, end); 465 } 466 #endif 467 } 468 469 /* 470 * mem_init() marks the free areas in the mem_map and tells us how much 471 * memory is free. This is done after various parts of the system have 472 * claimed their memory after the kernel image. 473 */ 474 void __init mem_init(void) 475 { 476 #ifdef CONFIG_HAVE_TCM 477 /* These pointers are filled in on TCM detection */ 478 extern u32 dtcm_end; 479 extern u32 itcm_end; 480 #endif 481 482 set_max_mapnr(pfn_to_page(max_pfn) - mem_map); 483 484 /* this will put all unused low memory onto the freelists */ 485 free_unused_memmap(); 486 memblock_free_all(); 487 488 #ifdef CONFIG_SA1111 489 /* now that our DMA memory is actually so designated, we can free it */ 490 free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL); 491 #endif 492 493 free_highpages(); 494 495 mem_init_print_info(NULL); 496 497 #define MLK(b, t) b, t, ((t) - (b)) >> 10 498 #define MLM(b, t) b, t, ((t) - (b)) >> 20 499 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K) 500 501 pr_notice("Virtual kernel memory layout:\n" 502 " vector : 0x%08lx - 0x%08lx (%4ld kB)\n" 503 #ifdef CONFIG_HAVE_TCM 504 " DTCM : 0x%08lx - 0x%08lx (%4ld kB)\n" 505 " ITCM : 0x%08lx - 0x%08lx (%4ld kB)\n" 506 #endif 507 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 508 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" 509 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" 510 #ifdef CONFIG_HIGHMEM 511 " pkmap : 0x%08lx - 0x%08lx (%4ld MB)\n" 512 #endif 513 #ifdef CONFIG_MODULES 514 " modules : 0x%08lx - 0x%08lx (%4ld MB)\n" 515 #endif 516 " .text : 0x%p" " - 0x%p" " (%4td kB)\n" 517 " .init : 0x%p" " - 0x%p" " (%4td kB)\n" 518 " .data : 0x%p" " - 0x%p" " (%4td kB)\n" 519 " .bss : 0x%p" " - 0x%p" " (%4td kB)\n", 520 521 MLK(VECTORS_BASE, VECTORS_BASE + PAGE_SIZE), 522 #ifdef CONFIG_HAVE_TCM 523 MLK(DTCM_OFFSET, (unsigned long) dtcm_end), 524 MLK(ITCM_OFFSET, (unsigned long) itcm_end), 525 #endif 526 MLK(FIXADDR_START, FIXADDR_END), 527 MLM(VMALLOC_START, VMALLOC_END), 528 MLM(PAGE_OFFSET, (unsigned long)high_memory), 529 #ifdef CONFIG_HIGHMEM 530 MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) * 531 (PAGE_SIZE)), 532 #endif 533 #ifdef CONFIG_MODULES 534 MLM(MODULES_VADDR, MODULES_END), 535 #endif 536 537 MLK_ROUNDUP(_text, _etext), 538 MLK_ROUNDUP(__init_begin, __init_end), 539 MLK_ROUNDUP(_sdata, _edata), 540 MLK_ROUNDUP(__bss_start, __bss_stop)); 541 542 #undef MLK 543 #undef MLM 544 #undef MLK_ROUNDUP 545 546 /* 547 * Check boundaries twice: Some fundamental inconsistencies can 548 * be detected at build time already. 549 */ 550 #ifdef CONFIG_MMU 551 BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR); 552 BUG_ON(TASK_SIZE > MODULES_VADDR); 553 #endif 554 555 #ifdef CONFIG_HIGHMEM 556 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET); 557 BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET); 558 #endif 559 } 560 561 #ifdef CONFIG_STRICT_KERNEL_RWX 562 struct section_perm { 563 const char *name; 564 unsigned long start; 565 unsigned long end; 566 pmdval_t mask; 567 pmdval_t prot; 568 pmdval_t clear; 569 }; 570 571 /* First section-aligned location at or after __start_rodata. */ 572 extern char __start_rodata_section_aligned[]; 573 574 static struct section_perm nx_perms[] = { 575 /* Make pages tables, etc before _stext RW (set NX). */ 576 { 577 .name = "pre-text NX", 578 .start = PAGE_OFFSET, 579 .end = (unsigned long)_stext, 580 .mask = ~PMD_SECT_XN, 581 .prot = PMD_SECT_XN, 582 }, 583 /* Make init RW (set NX). */ 584 { 585 .name = "init NX", 586 .start = (unsigned long)__init_begin, 587 .end = (unsigned long)_sdata, 588 .mask = ~PMD_SECT_XN, 589 .prot = PMD_SECT_XN, 590 }, 591 /* Make rodata NX (set RO in ro_perms below). */ 592 { 593 .name = "rodata NX", 594 .start = (unsigned long)__start_rodata_section_aligned, 595 .end = (unsigned long)__init_begin, 596 .mask = ~PMD_SECT_XN, 597 .prot = PMD_SECT_XN, 598 }, 599 }; 600 601 static struct section_perm ro_perms[] = { 602 /* Make kernel code and rodata RX (set RO). */ 603 { 604 .name = "text/rodata RO", 605 .start = (unsigned long)_stext, 606 .end = (unsigned long)__init_begin, 607 #ifdef CONFIG_ARM_LPAE 608 .mask = ~(L_PMD_SECT_RDONLY | PMD_SECT_AP2), 609 .prot = L_PMD_SECT_RDONLY | PMD_SECT_AP2, 610 #else 611 .mask = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE), 612 .prot = PMD_SECT_APX | PMD_SECT_AP_WRITE, 613 .clear = PMD_SECT_AP_WRITE, 614 #endif 615 }, 616 }; 617 618 /* 619 * Updates section permissions only for the current mm (sections are 620 * copied into each mm). During startup, this is the init_mm. Is only 621 * safe to be called with preemption disabled, as under stop_machine(). 622 */ 623 static inline void section_update(unsigned long addr, pmdval_t mask, 624 pmdval_t prot, struct mm_struct *mm) 625 { 626 pmd_t *pmd; 627 628 pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr); 629 630 #ifdef CONFIG_ARM_LPAE 631 pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot); 632 #else 633 if (addr & SECTION_SIZE) 634 pmd[1] = __pmd((pmd_val(pmd[1]) & mask) | prot); 635 else 636 pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot); 637 #endif 638 flush_pmd_entry(pmd); 639 local_flush_tlb_kernel_range(addr, addr + SECTION_SIZE); 640 } 641 642 /* Make sure extended page tables are in use. */ 643 static inline bool arch_has_strict_perms(void) 644 { 645 if (cpu_architecture() < CPU_ARCH_ARMv6) 646 return false; 647 648 return !!(get_cr() & CR_XP); 649 } 650 651 void set_section_perms(struct section_perm *perms, int n, bool set, 652 struct mm_struct *mm) 653 { 654 size_t i; 655 unsigned long addr; 656 657 if (!arch_has_strict_perms()) 658 return; 659 660 for (i = 0; i < n; i++) { 661 if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) || 662 !IS_ALIGNED(perms[i].end, SECTION_SIZE)) { 663 pr_err("BUG: %s section %lx-%lx not aligned to %lx\n", 664 perms[i].name, perms[i].start, perms[i].end, 665 SECTION_SIZE); 666 continue; 667 } 668 669 for (addr = perms[i].start; 670 addr < perms[i].end; 671 addr += SECTION_SIZE) 672 section_update(addr, perms[i].mask, 673 set ? perms[i].prot : perms[i].clear, mm); 674 } 675 676 } 677 678 /** 679 * update_sections_early intended to be called only through stop_machine 680 * framework and executed by only one CPU while all other CPUs will spin and 681 * wait, so no locking is required in this function. 682 */ 683 static void update_sections_early(struct section_perm perms[], int n) 684 { 685 struct task_struct *t, *s; 686 687 for_each_process(t) { 688 if (t->flags & PF_KTHREAD) 689 continue; 690 for_each_thread(t, s) 691 set_section_perms(perms, n, true, s->mm); 692 } 693 set_section_perms(perms, n, true, current->active_mm); 694 set_section_perms(perms, n, true, &init_mm); 695 } 696 697 static int __fix_kernmem_perms(void *unused) 698 { 699 update_sections_early(nx_perms, ARRAY_SIZE(nx_perms)); 700 return 0; 701 } 702 703 static void fix_kernmem_perms(void) 704 { 705 stop_machine(__fix_kernmem_perms, NULL, NULL); 706 } 707 708 static int __mark_rodata_ro(void *unused) 709 { 710 update_sections_early(ro_perms, ARRAY_SIZE(ro_perms)); 711 return 0; 712 } 713 714 static int kernel_set_to_readonly __read_mostly; 715 716 void mark_rodata_ro(void) 717 { 718 kernel_set_to_readonly = 1; 719 stop_machine(__mark_rodata_ro, NULL, NULL); 720 debug_checkwx(); 721 } 722 723 void set_kernel_text_rw(void) 724 { 725 if (!kernel_set_to_readonly) 726 return; 727 728 set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), false, 729 current->active_mm); 730 } 731 732 void set_kernel_text_ro(void) 733 { 734 if (!kernel_set_to_readonly) 735 return; 736 737 set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), true, 738 current->active_mm); 739 } 740 741 #else 742 static inline void fix_kernmem_perms(void) { } 743 #endif /* CONFIG_STRICT_KERNEL_RWX */ 744 745 void free_initmem(void) 746 { 747 fix_kernmem_perms(); 748 749 poison_init_mem(__init_begin, __init_end - __init_begin); 750 if (!machine_is_integrator() && !machine_is_cintegrator()) 751 free_initmem_default(-1); 752 } 753 754 #ifdef CONFIG_BLK_DEV_INITRD 755 756 static int keep_initrd; 757 758 void free_initrd_mem(unsigned long start, unsigned long end) 759 { 760 if (!keep_initrd) { 761 if (start == initrd_start) 762 start = round_down(start, PAGE_SIZE); 763 if (end == initrd_end) 764 end = round_up(end, PAGE_SIZE); 765 766 poison_init_mem((void *)start, PAGE_ALIGN(end) - start); 767 free_reserved_area((void *)start, (void *)end, -1, "initrd"); 768 } 769 } 770 771 static int __init keepinitrd_setup(char *__unused) 772 { 773 keep_initrd = 1; 774 return 1; 775 } 776 777 __setup("keepinitrd", keepinitrd_setup); 778 #endif 779