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/bootmem.h> 15 #include <linux/mman.h> 16 #include <linux/sched/signal.h> 17 #include <linux/sched/task.h> 18 #include <linux/export.h> 19 #include <linux/nodemask.h> 20 #include <linux/initrd.h> 21 #include <linux/of_fdt.h> 22 #include <linux/highmem.h> 23 #include <linux/gfp.h> 24 #include <linux/memblock.h> 25 #include <linux/dma-contiguous.h> 26 #include <linux/sizes.h> 27 #include <linux/stop_machine.h> 28 29 #include <asm/cp15.h> 30 #include <asm/mach-types.h> 31 #include <asm/memblock.h> 32 #include <asm/memory.h> 33 #include <asm/prom.h> 34 #include <asm/sections.h> 35 #include <asm/setup.h> 36 #include <asm/system_info.h> 37 #include <asm/tlb.h> 38 #include <asm/fixmap.h> 39 #include <asm/ptdump.h> 40 41 #include <asm/mach/arch.h> 42 #include <asm/mach/map.h> 43 44 #include "mm.h" 45 46 #ifdef CONFIG_CPU_CP15_MMU 47 unsigned long __init __clear_cr(unsigned long mask) 48 { 49 cr_alignment = cr_alignment & ~mask; 50 return cr_alignment; 51 } 52 #endif 53 54 static phys_addr_t phys_initrd_start __initdata = 0; 55 static unsigned long phys_initrd_size __initdata = 0; 56 57 static int __init early_initrd(char *p) 58 { 59 phys_addr_t start; 60 unsigned long size; 61 char *endp; 62 63 start = memparse(p, &endp); 64 if (*endp == ',') { 65 size = memparse(endp + 1, NULL); 66 67 phys_initrd_start = start; 68 phys_initrd_size = size; 69 } 70 return 0; 71 } 72 early_param("initrd", early_initrd); 73 74 static int __init parse_tag_initrd(const struct tag *tag) 75 { 76 pr_warn("ATAG_INITRD is deprecated; " 77 "please update your bootloader.\n"); 78 phys_initrd_start = __virt_to_phys(tag->u.initrd.start); 79 phys_initrd_size = tag->u.initrd.size; 80 return 0; 81 } 82 83 __tagtable(ATAG_INITRD, parse_tag_initrd); 84 85 static int __init parse_tag_initrd2(const struct tag *tag) 86 { 87 phys_initrd_start = tag->u.initrd.start; 88 phys_initrd_size = tag->u.initrd.size; 89 return 0; 90 } 91 92 __tagtable(ATAG_INITRD2, parse_tag_initrd2); 93 94 static void __init find_limits(unsigned long *min, unsigned long *max_low, 95 unsigned long *max_high) 96 { 97 *max_low = PFN_DOWN(memblock_get_current_limit()); 98 *min = PFN_UP(memblock_start_of_DRAM()); 99 *max_high = PFN_DOWN(memblock_end_of_DRAM()); 100 } 101 102 #ifdef CONFIG_ZONE_DMA 103 104 phys_addr_t arm_dma_zone_size __read_mostly; 105 EXPORT_SYMBOL(arm_dma_zone_size); 106 107 /* 108 * The DMA mask corresponding to the maximum bus address allocatable 109 * using GFP_DMA. The default here places no restriction on DMA 110 * allocations. This must be the smallest DMA mask in the system, 111 * so a successful GFP_DMA allocation will always satisfy this. 112 */ 113 phys_addr_t arm_dma_limit; 114 unsigned long arm_dma_pfn_limit; 115 116 static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole, 117 unsigned long dma_size) 118 { 119 if (size[0] <= dma_size) 120 return; 121 122 size[ZONE_NORMAL] = size[0] - dma_size; 123 size[ZONE_DMA] = dma_size; 124 hole[ZONE_NORMAL] = hole[0]; 125 hole[ZONE_DMA] = 0; 126 } 127 #endif 128 129 void __init setup_dma_zone(const struct machine_desc *mdesc) 130 { 131 #ifdef CONFIG_ZONE_DMA 132 if (mdesc->dma_zone_size) { 133 arm_dma_zone_size = mdesc->dma_zone_size; 134 arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1; 135 } else 136 arm_dma_limit = 0xffffffff; 137 arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT; 138 #endif 139 } 140 141 static void __init zone_sizes_init(unsigned long min, unsigned long max_low, 142 unsigned long max_high) 143 { 144 unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES]; 145 struct memblock_region *reg; 146 147 /* 148 * initialise the zones. 149 */ 150 memset(zone_size, 0, sizeof(zone_size)); 151 152 /* 153 * The memory size has already been determined. If we need 154 * to do anything fancy with the allocation of this memory 155 * to the zones, now is the time to do it. 156 */ 157 zone_size[0] = max_low - min; 158 #ifdef CONFIG_HIGHMEM 159 zone_size[ZONE_HIGHMEM] = max_high - max_low; 160 #endif 161 162 /* 163 * Calculate the size of the holes. 164 * holes = node_size - sum(bank_sizes) 165 */ 166 memcpy(zhole_size, zone_size, sizeof(zhole_size)); 167 for_each_memblock(memory, reg) { 168 unsigned long start = memblock_region_memory_base_pfn(reg); 169 unsigned long end = memblock_region_memory_end_pfn(reg); 170 171 if (start < max_low) { 172 unsigned long low_end = min(end, max_low); 173 zhole_size[0] -= low_end - start; 174 } 175 #ifdef CONFIG_HIGHMEM 176 if (end > max_low) { 177 unsigned long high_start = max(start, max_low); 178 zhole_size[ZONE_HIGHMEM] -= end - high_start; 179 } 180 #endif 181 } 182 183 #ifdef CONFIG_ZONE_DMA 184 /* 185 * Adjust the sizes according to any special requirements for 186 * this machine type. 187 */ 188 if (arm_dma_zone_size) 189 arm_adjust_dma_zone(zone_size, zhole_size, 190 arm_dma_zone_size >> PAGE_SHIFT); 191 #endif 192 193 free_area_init_node(0, zone_size, min, zhole_size); 194 } 195 196 #ifdef CONFIG_HAVE_ARCH_PFN_VALID 197 int pfn_valid(unsigned long pfn) 198 { 199 return memblock_is_map_memory(__pfn_to_phys(pfn)); 200 } 201 EXPORT_SYMBOL(pfn_valid); 202 #endif 203 204 #ifndef CONFIG_SPARSEMEM 205 static void __init arm_memory_present(void) 206 { 207 } 208 #else 209 static void __init arm_memory_present(void) 210 { 211 struct memblock_region *reg; 212 213 for_each_memblock(memory, reg) 214 memory_present(0, memblock_region_memory_base_pfn(reg), 215 memblock_region_memory_end_pfn(reg)); 216 } 217 #endif 218 219 static bool arm_memblock_steal_permitted = true; 220 221 phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align) 222 { 223 phys_addr_t phys; 224 225 BUG_ON(!arm_memblock_steal_permitted); 226 227 phys = memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE); 228 memblock_free(phys, size); 229 memblock_remove(phys, size); 230 231 return phys; 232 } 233 234 static void __init arm_initrd_init(void) 235 { 236 #ifdef CONFIG_BLK_DEV_INITRD 237 phys_addr_t start; 238 unsigned long size; 239 240 /* FDT scan will populate initrd_start */ 241 if (initrd_start && !phys_initrd_size) { 242 phys_initrd_start = __virt_to_phys(initrd_start); 243 phys_initrd_size = initrd_end - initrd_start; 244 } 245 246 initrd_start = initrd_end = 0; 247 248 if (!phys_initrd_size) 249 return; 250 251 /* 252 * Round the memory region to page boundaries as per free_initrd_mem() 253 * This allows us to detect whether the pages overlapping the initrd 254 * are in use, but more importantly, reserves the entire set of pages 255 * as we don't want these pages allocated for other purposes. 256 */ 257 start = round_down(phys_initrd_start, PAGE_SIZE); 258 size = phys_initrd_size + (phys_initrd_start - start); 259 size = round_up(size, PAGE_SIZE); 260 261 if (!memblock_is_region_memory(start, size)) { 262 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n", 263 (u64)start, size); 264 return; 265 } 266 267 if (memblock_is_region_reserved(start, size)) { 268 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n", 269 (u64)start, size); 270 return; 271 } 272 273 memblock_reserve(start, size); 274 275 /* Now convert initrd to virtual addresses */ 276 initrd_start = __phys_to_virt(phys_initrd_start); 277 initrd_end = initrd_start + phys_initrd_size; 278 #endif 279 } 280 281 void __init arm_memblock_init(const struct machine_desc *mdesc) 282 { 283 /* Register the kernel text, kernel data and initrd with memblock. */ 284 memblock_reserve(__pa(KERNEL_START), KERNEL_END - KERNEL_START); 285 286 arm_initrd_init(); 287 288 arm_mm_memblock_reserve(); 289 290 /* reserve any platform specific memblock areas */ 291 if (mdesc->reserve) 292 mdesc->reserve(); 293 294 early_init_fdt_reserve_self(); 295 early_init_fdt_scan_reserved_mem(); 296 297 /* reserve memory for DMA contiguous allocations */ 298 dma_contiguous_reserve(arm_dma_limit); 299 300 arm_memblock_steal_permitted = false; 301 memblock_dump_all(); 302 } 303 304 void __init bootmem_init(void) 305 { 306 unsigned long min, max_low, max_high; 307 308 memblock_allow_resize(); 309 max_low = max_high = 0; 310 311 find_limits(&min, &max_low, &max_high); 312 313 early_memtest((phys_addr_t)min << PAGE_SHIFT, 314 (phys_addr_t)max_low << PAGE_SHIFT); 315 316 /* 317 * Sparsemem tries to allocate bootmem in memory_present(), 318 * so must be done after the fixed reservations 319 */ 320 arm_memory_present(); 321 322 /* 323 * sparse_init() needs the bootmem allocator up and running. 324 */ 325 sparse_init(); 326 327 /* 328 * Now free the memory - free_area_init_node needs 329 * the sparse mem_map arrays initialized by sparse_init() 330 * for memmap_init_zone(), otherwise all PFNs are invalid. 331 */ 332 zone_sizes_init(min, max_low, max_high); 333 334 /* 335 * This doesn't seem to be used by the Linux memory manager any 336 * more, but is used by ll_rw_block. If we can get rid of it, we 337 * also get rid of some of the stuff above as well. 338 */ 339 min_low_pfn = min; 340 max_low_pfn = max_low; 341 max_pfn = max_high; 342 } 343 344 /* 345 * Poison init memory with an undefined instruction (ARM) or a branch to an 346 * undefined instruction (Thumb). 347 */ 348 static inline void poison_init_mem(void *s, size_t count) 349 { 350 u32 *p = (u32 *)s; 351 for (; count != 0; count -= 4) 352 *p++ = 0xe7fddef0; 353 } 354 355 static inline void 356 free_memmap(unsigned long start_pfn, unsigned long end_pfn) 357 { 358 struct page *start_pg, *end_pg; 359 phys_addr_t pg, pgend; 360 361 /* 362 * Convert start_pfn/end_pfn to a struct page pointer. 363 */ 364 start_pg = pfn_to_page(start_pfn - 1) + 1; 365 end_pg = pfn_to_page(end_pfn - 1) + 1; 366 367 /* 368 * Convert to physical addresses, and 369 * round start upwards and end downwards. 370 */ 371 pg = PAGE_ALIGN(__pa(start_pg)); 372 pgend = __pa(end_pg) & PAGE_MASK; 373 374 /* 375 * If there are free pages between these, 376 * free the section of the memmap array. 377 */ 378 if (pg < pgend) 379 memblock_free_early(pg, pgend - pg); 380 } 381 382 /* 383 * The mem_map array can get very big. Free the unused area of the memory map. 384 */ 385 static void __init free_unused_memmap(void) 386 { 387 unsigned long start, prev_end = 0; 388 struct memblock_region *reg; 389 390 /* 391 * This relies on each bank being in address order. 392 * The banks are sorted previously in bootmem_init(). 393 */ 394 for_each_memblock(memory, reg) { 395 start = memblock_region_memory_base_pfn(reg); 396 397 #ifdef CONFIG_SPARSEMEM 398 /* 399 * Take care not to free memmap entries that don't exist 400 * due to SPARSEMEM sections which aren't present. 401 */ 402 start = min(start, 403 ALIGN(prev_end, PAGES_PER_SECTION)); 404 #else 405 /* 406 * Align down here since the VM subsystem insists that the 407 * memmap entries are valid from the bank start aligned to 408 * MAX_ORDER_NR_PAGES. 409 */ 410 start = round_down(start, MAX_ORDER_NR_PAGES); 411 #endif 412 /* 413 * If we had a previous bank, and there is a space 414 * between the current bank and the previous, free it. 415 */ 416 if (prev_end && prev_end < start) 417 free_memmap(prev_end, start); 418 419 /* 420 * Align up here since the VM subsystem insists that the 421 * memmap entries are valid from the bank end aligned to 422 * MAX_ORDER_NR_PAGES. 423 */ 424 prev_end = ALIGN(memblock_region_memory_end_pfn(reg), 425 MAX_ORDER_NR_PAGES); 426 } 427 428 #ifdef CONFIG_SPARSEMEM 429 if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION)) 430 free_memmap(prev_end, 431 ALIGN(prev_end, PAGES_PER_SECTION)); 432 #endif 433 } 434 435 #ifdef CONFIG_HIGHMEM 436 static inline void free_area_high(unsigned long pfn, unsigned long end) 437 { 438 for (; pfn < end; pfn++) 439 free_highmem_page(pfn_to_page(pfn)); 440 } 441 #endif 442 443 static void __init free_highpages(void) 444 { 445 #ifdef CONFIG_HIGHMEM 446 unsigned long max_low = max_low_pfn; 447 struct memblock_region *mem, *res; 448 449 /* set highmem page free */ 450 for_each_memblock(memory, mem) { 451 unsigned long start = memblock_region_memory_base_pfn(mem); 452 unsigned long end = memblock_region_memory_end_pfn(mem); 453 454 /* Ignore complete lowmem entries */ 455 if (end <= max_low) 456 continue; 457 458 if (memblock_is_nomap(mem)) 459 continue; 460 461 /* Truncate partial highmem entries */ 462 if (start < max_low) 463 start = max_low; 464 465 /* Find and exclude any reserved regions */ 466 for_each_memblock(reserved, res) { 467 unsigned long res_start, res_end; 468 469 res_start = memblock_region_reserved_base_pfn(res); 470 res_end = memblock_region_reserved_end_pfn(res); 471 472 if (res_end < start) 473 continue; 474 if (res_start < start) 475 res_start = start; 476 if (res_start > end) 477 res_start = end; 478 if (res_end > end) 479 res_end = end; 480 if (res_start != start) 481 free_area_high(start, res_start); 482 start = res_end; 483 if (start == end) 484 break; 485 } 486 487 /* And now free anything which remains */ 488 if (start < end) 489 free_area_high(start, end); 490 } 491 #endif 492 } 493 494 /* 495 * mem_init() marks the free areas in the mem_map and tells us how much 496 * memory is free. This is done after various parts of the system have 497 * claimed their memory after the kernel image. 498 */ 499 void __init mem_init(void) 500 { 501 #ifdef CONFIG_HAVE_TCM 502 /* These pointers are filled in on TCM detection */ 503 extern u32 dtcm_end; 504 extern u32 itcm_end; 505 #endif 506 507 set_max_mapnr(pfn_to_page(max_pfn) - mem_map); 508 509 /* this will put all unused low memory onto the freelists */ 510 free_unused_memmap(); 511 free_all_bootmem(); 512 513 #ifdef CONFIG_SA1111 514 /* now that our DMA memory is actually so designated, we can free it */ 515 free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL); 516 #endif 517 518 free_highpages(); 519 520 mem_init_print_info(NULL); 521 522 #define MLK(b, t) b, t, ((t) - (b)) >> 10 523 #define MLM(b, t) b, t, ((t) - (b)) >> 20 524 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K) 525 526 pr_notice("Virtual kernel memory layout:\n" 527 " vector : 0x%08lx - 0x%08lx (%4ld kB)\n" 528 #ifdef CONFIG_HAVE_TCM 529 " DTCM : 0x%08lx - 0x%08lx (%4ld kB)\n" 530 " ITCM : 0x%08lx - 0x%08lx (%4ld kB)\n" 531 #endif 532 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 533 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" 534 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" 535 #ifdef CONFIG_HIGHMEM 536 " pkmap : 0x%08lx - 0x%08lx (%4ld MB)\n" 537 #endif 538 #ifdef CONFIG_MODULES 539 " modules : 0x%08lx - 0x%08lx (%4ld MB)\n" 540 #endif 541 " .text : 0x%p" " - 0x%p" " (%4td kB)\n" 542 " .init : 0x%p" " - 0x%p" " (%4td kB)\n" 543 " .data : 0x%p" " - 0x%p" " (%4td kB)\n" 544 " .bss : 0x%p" " - 0x%p" " (%4td kB)\n", 545 546 MLK(VECTORS_BASE, VECTORS_BASE + PAGE_SIZE), 547 #ifdef CONFIG_HAVE_TCM 548 MLK(DTCM_OFFSET, (unsigned long) dtcm_end), 549 MLK(ITCM_OFFSET, (unsigned long) itcm_end), 550 #endif 551 MLK(FIXADDR_START, FIXADDR_END), 552 MLM(VMALLOC_START, VMALLOC_END), 553 MLM(PAGE_OFFSET, (unsigned long)high_memory), 554 #ifdef CONFIG_HIGHMEM 555 MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) * 556 (PAGE_SIZE)), 557 #endif 558 #ifdef CONFIG_MODULES 559 MLM(MODULES_VADDR, MODULES_END), 560 #endif 561 562 MLK_ROUNDUP(_text, _etext), 563 MLK_ROUNDUP(__init_begin, __init_end), 564 MLK_ROUNDUP(_sdata, _edata), 565 MLK_ROUNDUP(__bss_start, __bss_stop)); 566 567 #undef MLK 568 #undef MLM 569 #undef MLK_ROUNDUP 570 571 /* 572 * Check boundaries twice: Some fundamental inconsistencies can 573 * be detected at build time already. 574 */ 575 #ifdef CONFIG_MMU 576 BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR); 577 BUG_ON(TASK_SIZE > MODULES_VADDR); 578 #endif 579 580 #ifdef CONFIG_HIGHMEM 581 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET); 582 BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET); 583 #endif 584 } 585 586 #ifdef CONFIG_STRICT_KERNEL_RWX 587 struct section_perm { 588 const char *name; 589 unsigned long start; 590 unsigned long end; 591 pmdval_t mask; 592 pmdval_t prot; 593 pmdval_t clear; 594 }; 595 596 /* First section-aligned location at or after __start_rodata. */ 597 extern char __start_rodata_section_aligned[]; 598 599 static struct section_perm nx_perms[] = { 600 /* Make pages tables, etc before _stext RW (set NX). */ 601 { 602 .name = "pre-text NX", 603 .start = PAGE_OFFSET, 604 .end = (unsigned long)_stext, 605 .mask = ~PMD_SECT_XN, 606 .prot = PMD_SECT_XN, 607 }, 608 /* Make init RW (set NX). */ 609 { 610 .name = "init NX", 611 .start = (unsigned long)__init_begin, 612 .end = (unsigned long)_sdata, 613 .mask = ~PMD_SECT_XN, 614 .prot = PMD_SECT_XN, 615 }, 616 /* Make rodata NX (set RO in ro_perms below). */ 617 { 618 .name = "rodata NX", 619 .start = (unsigned long)__start_rodata_section_aligned, 620 .end = (unsigned long)__init_begin, 621 .mask = ~PMD_SECT_XN, 622 .prot = PMD_SECT_XN, 623 }, 624 }; 625 626 static struct section_perm ro_perms[] = { 627 /* Make kernel code and rodata RX (set RO). */ 628 { 629 .name = "text/rodata RO", 630 .start = (unsigned long)_stext, 631 .end = (unsigned long)__init_begin, 632 #ifdef CONFIG_ARM_LPAE 633 .mask = ~(L_PMD_SECT_RDONLY | PMD_SECT_AP2), 634 .prot = L_PMD_SECT_RDONLY | PMD_SECT_AP2, 635 #else 636 .mask = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE), 637 .prot = PMD_SECT_APX | PMD_SECT_AP_WRITE, 638 .clear = PMD_SECT_AP_WRITE, 639 #endif 640 }, 641 }; 642 643 /* 644 * Updates section permissions only for the current mm (sections are 645 * copied into each mm). During startup, this is the init_mm. Is only 646 * safe to be called with preemption disabled, as under stop_machine(). 647 */ 648 static inline void section_update(unsigned long addr, pmdval_t mask, 649 pmdval_t prot, struct mm_struct *mm) 650 { 651 pmd_t *pmd; 652 653 pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr); 654 655 #ifdef CONFIG_ARM_LPAE 656 pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot); 657 #else 658 if (addr & SECTION_SIZE) 659 pmd[1] = __pmd((pmd_val(pmd[1]) & mask) | prot); 660 else 661 pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot); 662 #endif 663 flush_pmd_entry(pmd); 664 local_flush_tlb_kernel_range(addr, addr + SECTION_SIZE); 665 } 666 667 /* Make sure extended page tables are in use. */ 668 static inline bool arch_has_strict_perms(void) 669 { 670 if (cpu_architecture() < CPU_ARCH_ARMv6) 671 return false; 672 673 return !!(get_cr() & CR_XP); 674 } 675 676 void set_section_perms(struct section_perm *perms, int n, bool set, 677 struct mm_struct *mm) 678 { 679 size_t i; 680 unsigned long addr; 681 682 if (!arch_has_strict_perms()) 683 return; 684 685 for (i = 0; i < n; i++) { 686 if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) || 687 !IS_ALIGNED(perms[i].end, SECTION_SIZE)) { 688 pr_err("BUG: %s section %lx-%lx not aligned to %lx\n", 689 perms[i].name, perms[i].start, perms[i].end, 690 SECTION_SIZE); 691 continue; 692 } 693 694 for (addr = perms[i].start; 695 addr < perms[i].end; 696 addr += SECTION_SIZE) 697 section_update(addr, perms[i].mask, 698 set ? perms[i].prot : perms[i].clear, mm); 699 } 700 701 } 702 703 /** 704 * update_sections_early intended to be called only through stop_machine 705 * framework and executed by only one CPU while all other CPUs will spin and 706 * wait, so no locking is required in this function. 707 */ 708 static void update_sections_early(struct section_perm perms[], int n) 709 { 710 struct task_struct *t, *s; 711 712 for_each_process(t) { 713 if (t->flags & PF_KTHREAD) 714 continue; 715 for_each_thread(t, s) 716 set_section_perms(perms, n, true, s->mm); 717 } 718 set_section_perms(perms, n, true, current->active_mm); 719 set_section_perms(perms, n, true, &init_mm); 720 } 721 722 static int __fix_kernmem_perms(void *unused) 723 { 724 update_sections_early(nx_perms, ARRAY_SIZE(nx_perms)); 725 return 0; 726 } 727 728 static void fix_kernmem_perms(void) 729 { 730 stop_machine(__fix_kernmem_perms, NULL, NULL); 731 } 732 733 static int __mark_rodata_ro(void *unused) 734 { 735 update_sections_early(ro_perms, ARRAY_SIZE(ro_perms)); 736 return 0; 737 } 738 739 static int kernel_set_to_readonly __read_mostly; 740 741 void mark_rodata_ro(void) 742 { 743 kernel_set_to_readonly = 1; 744 stop_machine(__mark_rodata_ro, NULL, NULL); 745 debug_checkwx(); 746 } 747 748 void set_kernel_text_rw(void) 749 { 750 if (!kernel_set_to_readonly) 751 return; 752 753 set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), false, 754 current->active_mm); 755 } 756 757 void set_kernel_text_ro(void) 758 { 759 if (!kernel_set_to_readonly) 760 return; 761 762 set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), true, 763 current->active_mm); 764 } 765 766 #else 767 static inline void fix_kernmem_perms(void) { } 768 #endif /* CONFIG_STRICT_KERNEL_RWX */ 769 770 void free_initmem(void) 771 { 772 fix_kernmem_perms(); 773 774 poison_init_mem(__init_begin, __init_end - __init_begin); 775 if (!machine_is_integrator() && !machine_is_cintegrator()) 776 free_initmem_default(-1); 777 } 778 779 #ifdef CONFIG_BLK_DEV_INITRD 780 781 static int keep_initrd; 782 783 void free_initrd_mem(unsigned long start, unsigned long end) 784 { 785 if (!keep_initrd) { 786 if (start == initrd_start) 787 start = round_down(start, PAGE_SIZE); 788 if (end == initrd_end) 789 end = round_up(end, PAGE_SIZE); 790 791 poison_init_mem((void *)start, PAGE_ALIGN(end) - start); 792 free_reserved_area((void *)start, (void *)end, -1, "initrd"); 793 } 794 } 795 796 static int __init keepinitrd_setup(char *__unused) 797 { 798 keep_initrd = 1; 799 return 1; 800 } 801 802 __setup("keepinitrd", keepinitrd_setup); 803 #endif 804