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 early_initrd(char *p) 55 { 56 phys_addr_t start; 57 unsigned long size; 58 char *endp; 59 60 start = memparse(p, &endp); 61 if (*endp == ',') { 62 size = memparse(endp + 1, NULL); 63 64 phys_initrd_start = start; 65 phys_initrd_size = size; 66 } 67 return 0; 68 } 69 early_param("initrd", early_initrd); 70 71 static int __init parse_tag_initrd(const struct tag *tag) 72 { 73 pr_warn("ATAG_INITRD is deprecated; " 74 "please update your bootloader.\n"); 75 phys_initrd_start = __virt_to_phys(tag->u.initrd.start); 76 phys_initrd_size = tag->u.initrd.size; 77 return 0; 78 } 79 80 __tagtable(ATAG_INITRD, parse_tag_initrd); 81 82 static int __init parse_tag_initrd2(const struct tag *tag) 83 { 84 phys_initrd_start = tag->u.initrd.start; 85 phys_initrd_size = tag->u.initrd.size; 86 return 0; 87 } 88 89 __tagtable(ATAG_INITRD2, parse_tag_initrd2); 90 #endif 91 92 static void __init find_limits(unsigned long *min, unsigned long *max_low, 93 unsigned long *max_high) 94 { 95 *max_low = PFN_DOWN(memblock_get_current_limit()); 96 *min = PFN_UP(memblock_start_of_DRAM()); 97 *max_high = PFN_DOWN(memblock_end_of_DRAM()); 98 } 99 100 #ifdef CONFIG_ZONE_DMA 101 102 phys_addr_t arm_dma_zone_size __read_mostly; 103 EXPORT_SYMBOL(arm_dma_zone_size); 104 105 /* 106 * The DMA mask corresponding to the maximum bus address allocatable 107 * using GFP_DMA. The default here places no restriction on DMA 108 * allocations. This must be the smallest DMA mask in the system, 109 * so a successful GFP_DMA allocation will always satisfy this. 110 */ 111 phys_addr_t arm_dma_limit; 112 unsigned long arm_dma_pfn_limit; 113 114 static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole, 115 unsigned long dma_size) 116 { 117 if (size[0] <= dma_size) 118 return; 119 120 size[ZONE_NORMAL] = size[0] - dma_size; 121 size[ZONE_DMA] = dma_size; 122 hole[ZONE_NORMAL] = hole[0]; 123 hole[ZONE_DMA] = 0; 124 } 125 #endif 126 127 void __init setup_dma_zone(const struct machine_desc *mdesc) 128 { 129 #ifdef CONFIG_ZONE_DMA 130 if (mdesc->dma_zone_size) { 131 arm_dma_zone_size = mdesc->dma_zone_size; 132 arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1; 133 } else 134 arm_dma_limit = 0xffffffff; 135 arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT; 136 #endif 137 } 138 139 static void __init zone_sizes_init(unsigned long min, unsigned long max_low, 140 unsigned long max_high) 141 { 142 unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES]; 143 struct memblock_region *reg; 144 145 /* 146 * initialise the zones. 147 */ 148 memset(zone_size, 0, sizeof(zone_size)); 149 150 /* 151 * The memory size has already been determined. If we need 152 * to do anything fancy with the allocation of this memory 153 * to the zones, now is the time to do it. 154 */ 155 zone_size[0] = max_low - min; 156 #ifdef CONFIG_HIGHMEM 157 zone_size[ZONE_HIGHMEM] = max_high - max_low; 158 #endif 159 160 /* 161 * Calculate the size of the holes. 162 * holes = node_size - sum(bank_sizes) 163 */ 164 memcpy(zhole_size, zone_size, sizeof(zhole_size)); 165 for_each_memblock(memory, reg) { 166 unsigned long start = memblock_region_memory_base_pfn(reg); 167 unsigned long end = memblock_region_memory_end_pfn(reg); 168 169 if (start < max_low) { 170 unsigned long low_end = min(end, max_low); 171 zhole_size[0] -= low_end - start; 172 } 173 #ifdef CONFIG_HIGHMEM 174 if (end > max_low) { 175 unsigned long high_start = max(start, max_low); 176 zhole_size[ZONE_HIGHMEM] -= end - high_start; 177 } 178 #endif 179 } 180 181 #ifdef CONFIG_ZONE_DMA 182 /* 183 * Adjust the sizes according to any special requirements for 184 * this machine type. 185 */ 186 if (arm_dma_zone_size) 187 arm_adjust_dma_zone(zone_size, zhole_size, 188 arm_dma_zone_size >> PAGE_SHIFT); 189 #endif 190 191 free_area_init_node(0, zone_size, min, zhole_size); 192 } 193 194 #ifdef CONFIG_HAVE_ARCH_PFN_VALID 195 int pfn_valid(unsigned long pfn) 196 { 197 return memblock_is_map_memory(__pfn_to_phys(pfn)); 198 } 199 EXPORT_SYMBOL(pfn_valid); 200 #endif 201 202 #ifndef CONFIG_SPARSEMEM 203 static void __init arm_memory_present(void) 204 { 205 } 206 #else 207 static void __init arm_memory_present(void) 208 { 209 struct memblock_region *reg; 210 211 for_each_memblock(memory, reg) 212 memory_present(0, memblock_region_memory_base_pfn(reg), 213 memblock_region_memory_end_pfn(reg)); 214 } 215 #endif 216 217 static bool arm_memblock_steal_permitted = true; 218 219 phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align) 220 { 221 phys_addr_t phys; 222 223 BUG_ON(!arm_memblock_steal_permitted); 224 225 phys = memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE); 226 memblock_free(phys, size); 227 memblock_remove(phys, size); 228 229 return phys; 230 } 231 232 static void __init arm_initrd_init(void) 233 { 234 #ifdef CONFIG_BLK_DEV_INITRD 235 phys_addr_t start; 236 unsigned long size; 237 238 initrd_start = initrd_end = 0; 239 240 if (!phys_initrd_size) 241 return; 242 243 /* 244 * Round the memory region to page boundaries as per free_initrd_mem() 245 * This allows us to detect whether the pages overlapping the initrd 246 * are in use, but more importantly, reserves the entire set of pages 247 * as we don't want these pages allocated for other purposes. 248 */ 249 start = round_down(phys_initrd_start, PAGE_SIZE); 250 size = phys_initrd_size + (phys_initrd_start - start); 251 size = round_up(size, PAGE_SIZE); 252 253 if (!memblock_is_region_memory(start, size)) { 254 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n", 255 (u64)start, size); 256 return; 257 } 258 259 if (memblock_is_region_reserved(start, size)) { 260 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n", 261 (u64)start, size); 262 return; 263 } 264 265 memblock_reserve(start, size); 266 267 /* Now convert initrd to virtual addresses */ 268 initrd_start = __phys_to_virt(phys_initrd_start); 269 initrd_end = initrd_start + phys_initrd_size; 270 #endif 271 } 272 273 void __init arm_memblock_init(const struct machine_desc *mdesc) 274 { 275 /* Register the kernel text, kernel data and initrd with memblock. */ 276 memblock_reserve(__pa(KERNEL_START), KERNEL_END - KERNEL_START); 277 278 arm_initrd_init(); 279 280 arm_mm_memblock_reserve(); 281 282 /* reserve any platform specific memblock areas */ 283 if (mdesc->reserve) 284 mdesc->reserve(); 285 286 early_init_fdt_reserve_self(); 287 early_init_fdt_scan_reserved_mem(); 288 289 /* reserve memory for DMA contiguous allocations */ 290 dma_contiguous_reserve(arm_dma_limit); 291 292 arm_memblock_steal_permitted = false; 293 memblock_dump_all(); 294 } 295 296 void __init bootmem_init(void) 297 { 298 unsigned long min, max_low, max_high; 299 300 memblock_allow_resize(); 301 max_low = max_high = 0; 302 303 find_limits(&min, &max_low, &max_high); 304 305 early_memtest((phys_addr_t)min << PAGE_SHIFT, 306 (phys_addr_t)max_low << PAGE_SHIFT); 307 308 /* 309 * Sparsemem tries to allocate bootmem in memory_present(), 310 * so must be done after the fixed reservations 311 */ 312 arm_memory_present(); 313 314 /* 315 * sparse_init() needs the bootmem allocator up and running. 316 */ 317 sparse_init(); 318 319 /* 320 * Now free the memory - free_area_init_node needs 321 * the sparse mem_map arrays initialized by sparse_init() 322 * for memmap_init_zone(), otherwise all PFNs are invalid. 323 */ 324 zone_sizes_init(min, max_low, max_high); 325 326 /* 327 * This doesn't seem to be used by the Linux memory manager any 328 * more, but is used by ll_rw_block. If we can get rid of it, we 329 * also get rid of some of the stuff above as well. 330 */ 331 min_low_pfn = min; 332 max_low_pfn = max_low; 333 max_pfn = max_high; 334 } 335 336 /* 337 * Poison init memory with an undefined instruction (ARM) or a branch to an 338 * undefined instruction (Thumb). 339 */ 340 static inline void poison_init_mem(void *s, size_t count) 341 { 342 u32 *p = (u32 *)s; 343 for (; count != 0; count -= 4) 344 *p++ = 0xe7fddef0; 345 } 346 347 static inline void 348 free_memmap(unsigned long start_pfn, unsigned long end_pfn) 349 { 350 struct page *start_pg, *end_pg; 351 phys_addr_t pg, pgend; 352 353 /* 354 * Convert start_pfn/end_pfn to a struct page pointer. 355 */ 356 start_pg = pfn_to_page(start_pfn - 1) + 1; 357 end_pg = pfn_to_page(end_pfn - 1) + 1; 358 359 /* 360 * Convert to physical addresses, and 361 * round start upwards and end downwards. 362 */ 363 pg = PAGE_ALIGN(__pa(start_pg)); 364 pgend = __pa(end_pg) & PAGE_MASK; 365 366 /* 367 * If there are free pages between these, 368 * free the section of the memmap array. 369 */ 370 if (pg < pgend) 371 memblock_free_early(pg, pgend - pg); 372 } 373 374 /* 375 * The mem_map array can get very big. Free the unused area of the memory map. 376 */ 377 static void __init free_unused_memmap(void) 378 { 379 unsigned long start, prev_end = 0; 380 struct memblock_region *reg; 381 382 /* 383 * This relies on each bank being in address order. 384 * The banks are sorted previously in bootmem_init(). 385 */ 386 for_each_memblock(memory, reg) { 387 start = memblock_region_memory_base_pfn(reg); 388 389 #ifdef CONFIG_SPARSEMEM 390 /* 391 * Take care not to free memmap entries that don't exist 392 * due to SPARSEMEM sections which aren't present. 393 */ 394 start = min(start, 395 ALIGN(prev_end, PAGES_PER_SECTION)); 396 #else 397 /* 398 * Align down here since the VM subsystem insists that the 399 * memmap entries are valid from the bank start aligned to 400 * MAX_ORDER_NR_PAGES. 401 */ 402 start = round_down(start, MAX_ORDER_NR_PAGES); 403 #endif 404 /* 405 * If we had a previous bank, and there is a space 406 * between the current bank and the previous, free it. 407 */ 408 if (prev_end && prev_end < start) 409 free_memmap(prev_end, start); 410 411 /* 412 * Align up here since the VM subsystem insists that the 413 * memmap entries are valid from the bank end aligned to 414 * MAX_ORDER_NR_PAGES. 415 */ 416 prev_end = ALIGN(memblock_region_memory_end_pfn(reg), 417 MAX_ORDER_NR_PAGES); 418 } 419 420 #ifdef CONFIG_SPARSEMEM 421 if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION)) 422 free_memmap(prev_end, 423 ALIGN(prev_end, PAGES_PER_SECTION)); 424 #endif 425 } 426 427 #ifdef CONFIG_HIGHMEM 428 static inline void free_area_high(unsigned long pfn, unsigned long end) 429 { 430 for (; pfn < end; pfn++) 431 free_highmem_page(pfn_to_page(pfn)); 432 } 433 #endif 434 435 static void __init free_highpages(void) 436 { 437 #ifdef CONFIG_HIGHMEM 438 unsigned long max_low = max_low_pfn; 439 struct memblock_region *mem, *res; 440 441 /* set highmem page free */ 442 for_each_memblock(memory, mem) { 443 unsigned long start = memblock_region_memory_base_pfn(mem); 444 unsigned long end = memblock_region_memory_end_pfn(mem); 445 446 /* Ignore complete lowmem entries */ 447 if (end <= max_low) 448 continue; 449 450 if (memblock_is_nomap(mem)) 451 continue; 452 453 /* Truncate partial highmem entries */ 454 if (start < max_low) 455 start = max_low; 456 457 /* Find and exclude any reserved regions */ 458 for_each_memblock(reserved, res) { 459 unsigned long res_start, res_end; 460 461 res_start = memblock_region_reserved_base_pfn(res); 462 res_end = memblock_region_reserved_end_pfn(res); 463 464 if (res_end < start) 465 continue; 466 if (res_start < start) 467 res_start = start; 468 if (res_start > end) 469 res_start = end; 470 if (res_end > end) 471 res_end = end; 472 if (res_start != start) 473 free_area_high(start, res_start); 474 start = res_end; 475 if (start == end) 476 break; 477 } 478 479 /* And now free anything which remains */ 480 if (start < end) 481 free_area_high(start, end); 482 } 483 #endif 484 } 485 486 /* 487 * mem_init() marks the free areas in the mem_map and tells us how much 488 * memory is free. This is done after various parts of the system have 489 * claimed their memory after the kernel image. 490 */ 491 void __init mem_init(void) 492 { 493 #ifdef CONFIG_HAVE_TCM 494 /* These pointers are filled in on TCM detection */ 495 extern u32 dtcm_end; 496 extern u32 itcm_end; 497 #endif 498 499 set_max_mapnr(pfn_to_page(max_pfn) - mem_map); 500 501 /* this will put all unused low memory onto the freelists */ 502 free_unused_memmap(); 503 memblock_free_all(); 504 505 #ifdef CONFIG_SA1111 506 /* now that our DMA memory is actually so designated, we can free it */ 507 free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL); 508 #endif 509 510 free_highpages(); 511 512 mem_init_print_info(NULL); 513 514 #define MLK(b, t) b, t, ((t) - (b)) >> 10 515 #define MLM(b, t) b, t, ((t) - (b)) >> 20 516 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K) 517 518 pr_notice("Virtual kernel memory layout:\n" 519 " vector : 0x%08lx - 0x%08lx (%4ld kB)\n" 520 #ifdef CONFIG_HAVE_TCM 521 " DTCM : 0x%08lx - 0x%08lx (%4ld kB)\n" 522 " ITCM : 0x%08lx - 0x%08lx (%4ld kB)\n" 523 #endif 524 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 525 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" 526 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" 527 #ifdef CONFIG_HIGHMEM 528 " pkmap : 0x%08lx - 0x%08lx (%4ld MB)\n" 529 #endif 530 #ifdef CONFIG_MODULES 531 " modules : 0x%08lx - 0x%08lx (%4ld MB)\n" 532 #endif 533 " .text : 0x%p" " - 0x%p" " (%4td kB)\n" 534 " .init : 0x%p" " - 0x%p" " (%4td kB)\n" 535 " .data : 0x%p" " - 0x%p" " (%4td kB)\n" 536 " .bss : 0x%p" " - 0x%p" " (%4td kB)\n", 537 538 MLK(VECTORS_BASE, VECTORS_BASE + PAGE_SIZE), 539 #ifdef CONFIG_HAVE_TCM 540 MLK(DTCM_OFFSET, (unsigned long) dtcm_end), 541 MLK(ITCM_OFFSET, (unsigned long) itcm_end), 542 #endif 543 MLK(FIXADDR_START, FIXADDR_END), 544 MLM(VMALLOC_START, VMALLOC_END), 545 MLM(PAGE_OFFSET, (unsigned long)high_memory), 546 #ifdef CONFIG_HIGHMEM 547 MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) * 548 (PAGE_SIZE)), 549 #endif 550 #ifdef CONFIG_MODULES 551 MLM(MODULES_VADDR, MODULES_END), 552 #endif 553 554 MLK_ROUNDUP(_text, _etext), 555 MLK_ROUNDUP(__init_begin, __init_end), 556 MLK_ROUNDUP(_sdata, _edata), 557 MLK_ROUNDUP(__bss_start, __bss_stop)); 558 559 #undef MLK 560 #undef MLM 561 #undef MLK_ROUNDUP 562 563 /* 564 * Check boundaries twice: Some fundamental inconsistencies can 565 * be detected at build time already. 566 */ 567 #ifdef CONFIG_MMU 568 BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR); 569 BUG_ON(TASK_SIZE > MODULES_VADDR); 570 #endif 571 572 #ifdef CONFIG_HIGHMEM 573 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET); 574 BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET); 575 #endif 576 } 577 578 #ifdef CONFIG_STRICT_KERNEL_RWX 579 struct section_perm { 580 const char *name; 581 unsigned long start; 582 unsigned long end; 583 pmdval_t mask; 584 pmdval_t prot; 585 pmdval_t clear; 586 }; 587 588 /* First section-aligned location at or after __start_rodata. */ 589 extern char __start_rodata_section_aligned[]; 590 591 static struct section_perm nx_perms[] = { 592 /* Make pages tables, etc before _stext RW (set NX). */ 593 { 594 .name = "pre-text NX", 595 .start = PAGE_OFFSET, 596 .end = (unsigned long)_stext, 597 .mask = ~PMD_SECT_XN, 598 .prot = PMD_SECT_XN, 599 }, 600 /* Make init RW (set NX). */ 601 { 602 .name = "init NX", 603 .start = (unsigned long)__init_begin, 604 .end = (unsigned long)_sdata, 605 .mask = ~PMD_SECT_XN, 606 .prot = PMD_SECT_XN, 607 }, 608 /* Make rodata NX (set RO in ro_perms below). */ 609 { 610 .name = "rodata NX", 611 .start = (unsigned long)__start_rodata_section_aligned, 612 .end = (unsigned long)__init_begin, 613 .mask = ~PMD_SECT_XN, 614 .prot = PMD_SECT_XN, 615 }, 616 }; 617 618 static struct section_perm ro_perms[] = { 619 /* Make kernel code and rodata RX (set RO). */ 620 { 621 .name = "text/rodata RO", 622 .start = (unsigned long)_stext, 623 .end = (unsigned long)__init_begin, 624 #ifdef CONFIG_ARM_LPAE 625 .mask = ~(L_PMD_SECT_RDONLY | PMD_SECT_AP2), 626 .prot = L_PMD_SECT_RDONLY | PMD_SECT_AP2, 627 #else 628 .mask = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE), 629 .prot = PMD_SECT_APX | PMD_SECT_AP_WRITE, 630 .clear = PMD_SECT_AP_WRITE, 631 #endif 632 }, 633 }; 634 635 /* 636 * Updates section permissions only for the current mm (sections are 637 * copied into each mm). During startup, this is the init_mm. Is only 638 * safe to be called with preemption disabled, as under stop_machine(). 639 */ 640 static inline void section_update(unsigned long addr, pmdval_t mask, 641 pmdval_t prot, struct mm_struct *mm) 642 { 643 pmd_t *pmd; 644 645 pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr); 646 647 #ifdef CONFIG_ARM_LPAE 648 pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot); 649 #else 650 if (addr & SECTION_SIZE) 651 pmd[1] = __pmd((pmd_val(pmd[1]) & mask) | prot); 652 else 653 pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot); 654 #endif 655 flush_pmd_entry(pmd); 656 local_flush_tlb_kernel_range(addr, addr + SECTION_SIZE); 657 } 658 659 /* Make sure extended page tables are in use. */ 660 static inline bool arch_has_strict_perms(void) 661 { 662 if (cpu_architecture() < CPU_ARCH_ARMv6) 663 return false; 664 665 return !!(get_cr() & CR_XP); 666 } 667 668 void set_section_perms(struct section_perm *perms, int n, bool set, 669 struct mm_struct *mm) 670 { 671 size_t i; 672 unsigned long addr; 673 674 if (!arch_has_strict_perms()) 675 return; 676 677 for (i = 0; i < n; i++) { 678 if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) || 679 !IS_ALIGNED(perms[i].end, SECTION_SIZE)) { 680 pr_err("BUG: %s section %lx-%lx not aligned to %lx\n", 681 perms[i].name, perms[i].start, perms[i].end, 682 SECTION_SIZE); 683 continue; 684 } 685 686 for (addr = perms[i].start; 687 addr < perms[i].end; 688 addr += SECTION_SIZE) 689 section_update(addr, perms[i].mask, 690 set ? perms[i].prot : perms[i].clear, mm); 691 } 692 693 } 694 695 /** 696 * update_sections_early intended to be called only through stop_machine 697 * framework and executed by only one CPU while all other CPUs will spin and 698 * wait, so no locking is required in this function. 699 */ 700 static void update_sections_early(struct section_perm perms[], int n) 701 { 702 struct task_struct *t, *s; 703 704 for_each_process(t) { 705 if (t->flags & PF_KTHREAD) 706 continue; 707 for_each_thread(t, s) 708 set_section_perms(perms, n, true, s->mm); 709 } 710 set_section_perms(perms, n, true, current->active_mm); 711 set_section_perms(perms, n, true, &init_mm); 712 } 713 714 static int __fix_kernmem_perms(void *unused) 715 { 716 update_sections_early(nx_perms, ARRAY_SIZE(nx_perms)); 717 return 0; 718 } 719 720 static void fix_kernmem_perms(void) 721 { 722 stop_machine(__fix_kernmem_perms, NULL, NULL); 723 } 724 725 static int __mark_rodata_ro(void *unused) 726 { 727 update_sections_early(ro_perms, ARRAY_SIZE(ro_perms)); 728 return 0; 729 } 730 731 static int kernel_set_to_readonly __read_mostly; 732 733 void mark_rodata_ro(void) 734 { 735 kernel_set_to_readonly = 1; 736 stop_machine(__mark_rodata_ro, NULL, NULL); 737 debug_checkwx(); 738 } 739 740 void set_kernel_text_rw(void) 741 { 742 if (!kernel_set_to_readonly) 743 return; 744 745 set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), false, 746 current->active_mm); 747 } 748 749 void set_kernel_text_ro(void) 750 { 751 if (!kernel_set_to_readonly) 752 return; 753 754 set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), true, 755 current->active_mm); 756 } 757 758 #else 759 static inline void fix_kernmem_perms(void) { } 760 #endif /* CONFIG_STRICT_KERNEL_RWX */ 761 762 void free_initmem(void) 763 { 764 fix_kernmem_perms(); 765 766 poison_init_mem(__init_begin, __init_end - __init_begin); 767 if (!machine_is_integrator() && !machine_is_cintegrator()) 768 free_initmem_default(-1); 769 } 770 771 #ifdef CONFIG_BLK_DEV_INITRD 772 773 static int keep_initrd; 774 775 void free_initrd_mem(unsigned long start, unsigned long end) 776 { 777 if (!keep_initrd) { 778 if (start == initrd_start) 779 start = round_down(start, PAGE_SIZE); 780 if (end == initrd_end) 781 end = round_up(end, PAGE_SIZE); 782 783 poison_init_mem((void *)start, PAGE_ALIGN(end) - start); 784 free_reserved_area((void *)start, (void *)end, -1, "initrd"); 785 } 786 } 787 788 static int __init keepinitrd_setup(char *__unused) 789 { 790 keep_initrd = 1; 791 return 1; 792 } 793 794 __setup("keepinitrd", keepinitrd_setup); 795 #endif 796