arch/x86/mm/dump_pagetables.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
printk_prot
normalize_addr
note_wx
note_page
effective_prot
walk_pte_level
kasan_page_table
kasan_page_table
walk_pmd_level
walk_pud_level
walk_p4d_level
is_hypervisor_range
ptdump_walk_pgd_level_core
ptdump_walk_pgd_level
ptdump_walk_pgd_level_debugfs
ptdump_walk_user_pgd_level_checkwx
ptdump_walk_pgd_level_checkwx
pt_dump_init
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Debug helper to dump the current kernel pagetables of the system
   4  * so that we can see what the various memory ranges are set to.
   5  *
   6  * (C) Copyright 2008 Intel Corporation
   7  *
   8  * Author: Arjan van de Ven <arjan@linux.intel.com>
   9  */
  10 
  11 #include <linux/debugfs.h>
  12 #include <linux/kasan.h>
  13 #include <linux/mm.h>
  14 #include <linux/init.h>
  15 #include <linux/sched.h>
  16 #include <linux/seq_file.h>
  17 #include <linux/highmem.h>
  18 #include <linux/pci.h>
  19 
  20 #include <asm/e820/types.h>
  21 #include <asm/pgtable.h>
  22 
  23 /*
  24  * The dumper groups pagetable entries of the same type into one, and for
  25  * that it needs to keep some state when walking, and flush this state
  26  * when a "break" in the continuity is found.
  27  */
  28 struct pg_state {
  29         int level;
  30         pgprot_t current_prot;
  31         pgprotval_t effective_prot;
  32         unsigned long start_address;
  33         unsigned long current_address;
  34         const struct addr_marker *marker;
  35         unsigned long lines;
  36         bool to_dmesg;
  37         bool check_wx;
  38         unsigned long wx_pages;
  39 };
  40 
  41 struct addr_marker {
  42         unsigned long start_address;
  43         const char *name;
  44         unsigned long max_lines;
  45 };
  46 
  47 /* Address space markers hints */
  48 
  49 #ifdef CONFIG_X86_64
  50 
  51 enum address_markers_idx {
  52         USER_SPACE_NR = 0,
  53         KERNEL_SPACE_NR,
  54 #ifdef CONFIG_MODIFY_LDT_SYSCALL
  55         LDT_NR,
  56 #endif
  57         LOW_KERNEL_NR,
  58         VMALLOC_START_NR,
  59         VMEMMAP_START_NR,
  60 #ifdef CONFIG_KASAN
  61         KASAN_SHADOW_START_NR,
  62         KASAN_SHADOW_END_NR,
  63 #endif
  64         CPU_ENTRY_AREA_NR,
  65 #ifdef CONFIG_X86_ESPFIX64
  66         ESPFIX_START_NR,
  67 #endif
  68 #ifdef CONFIG_EFI
  69         EFI_END_NR,
  70 #endif
  71         HIGH_KERNEL_NR,
  72         MODULES_VADDR_NR,
  73         MODULES_END_NR,
  74         FIXADDR_START_NR,
  75         END_OF_SPACE_NR,
  76 };
  77 
  78 static struct addr_marker address_markers[] = {
  79         [USER_SPACE_NR]         = { 0,                  "User Space" },
  80         [KERNEL_SPACE_NR]       = { (1UL << 63),        "Kernel Space" },
  81         [LOW_KERNEL_NR]         = { 0UL,                "Low Kernel Mapping" },
  82         [VMALLOC_START_NR]      = { 0UL,                "vmalloc() Area" },
  83         [VMEMMAP_START_NR]      = { 0UL,                "Vmemmap" },
  84 #ifdef CONFIG_KASAN
  85         /*
  86          * These fields get initialized with the (dynamic)
  87          * KASAN_SHADOW_{START,END} values in pt_dump_init().
  88          */
  89         [KASAN_SHADOW_START_NR] = { 0UL,                "KASAN shadow" },
  90         [KASAN_SHADOW_END_NR]   = { 0UL,                "KASAN shadow end" },
  91 #endif
  92 #ifdef CONFIG_MODIFY_LDT_SYSCALL
  93         [LDT_NR]                = { 0UL,                "LDT remap" },
  94 #endif
  95         [CPU_ENTRY_AREA_NR]     = { CPU_ENTRY_AREA_BASE,"CPU entry Area" },
  96 #ifdef CONFIG_X86_ESPFIX64
  97         [ESPFIX_START_NR]       = { ESPFIX_BASE_ADDR,   "ESPfix Area", 16 },
  98 #endif
  99 #ifdef CONFIG_EFI
 100         [EFI_END_NR]            = { EFI_VA_END,         "EFI Runtime Services" },
 101 #endif
 102         [HIGH_KERNEL_NR]        = { __START_KERNEL_map, "High Kernel Mapping" },
 103         [MODULES_VADDR_NR]      = { MODULES_VADDR,      "Modules" },
 104         [MODULES_END_NR]        = { MODULES_END,        "End Modules" },
 105         [FIXADDR_START_NR]      = { FIXADDR_START,      "Fixmap Area" },
 106         [END_OF_SPACE_NR]       = { -1,                 NULL }
 107 };
 108 
 109 #define INIT_PGD        ((pgd_t *) &init_top_pgt)
 110 
 111 #else /* CONFIG_X86_64 */
 112 
 113 enum address_markers_idx {
 114         USER_SPACE_NR = 0,
 115         KERNEL_SPACE_NR,
 116         VMALLOC_START_NR,
 117         VMALLOC_END_NR,
 118 #ifdef CONFIG_HIGHMEM
 119         PKMAP_BASE_NR,
 120 #endif
 121 #ifdef CONFIG_MODIFY_LDT_SYSCALL
 122         LDT_NR,
 123 #endif
 124         CPU_ENTRY_AREA_NR,
 125         FIXADDR_START_NR,
 126         END_OF_SPACE_NR,
 127 };
 128 
 129 static struct addr_marker address_markers[] = {
 130         [USER_SPACE_NR]         = { 0,                  "User Space" },
 131         [KERNEL_SPACE_NR]       = { PAGE_OFFSET,        "Kernel Mapping" },
 132         [VMALLOC_START_NR]      = { 0UL,                "vmalloc() Area" },
 133         [VMALLOC_END_NR]        = { 0UL,                "vmalloc() End" },
 134 #ifdef CONFIG_HIGHMEM
 135         [PKMAP_BASE_NR]         = { 0UL,                "Persistent kmap() Area" },
 136 #endif
 137 #ifdef CONFIG_MODIFY_LDT_SYSCALL
 138         [LDT_NR]                = { 0UL,                "LDT remap" },
 139 #endif
 140         [CPU_ENTRY_AREA_NR]     = { 0UL,                "CPU entry area" },
 141         [FIXADDR_START_NR]      = { 0UL,                "Fixmap area" },
 142         [END_OF_SPACE_NR]       = { -1,                 NULL }
 143 };
 144 
 145 #define INIT_PGD        (swapper_pg_dir)
 146 
 147 #endif /* !CONFIG_X86_64 */
 148 
 149 /* Multipliers for offsets within the PTEs */
 150 #define PTE_LEVEL_MULT (PAGE_SIZE)
 151 #define PMD_LEVEL_MULT (PTRS_PER_PTE * PTE_LEVEL_MULT)
 152 #define PUD_LEVEL_MULT (PTRS_PER_PMD * PMD_LEVEL_MULT)
 153 #define P4D_LEVEL_MULT (PTRS_PER_PUD * PUD_LEVEL_MULT)
 154 #define PGD_LEVEL_MULT (PTRS_PER_P4D * P4D_LEVEL_MULT)
 155 
 156 #define pt_dump_seq_printf(m, to_dmesg, fmt, args...)           \
 157 ({                                                              \
 158         if (to_dmesg)                                   \
 159                 printk(KERN_INFO fmt, ##args);                  \
 160         else                                                    \
 161                 if (m)                                          \
 162                         seq_printf(m, fmt, ##args);             \
 163 })
 164 
 165 #define pt_dump_cont_printf(m, to_dmesg, fmt, args...)          \
 166 ({                                                              \
 167         if (to_dmesg)                                   \
 168                 printk(KERN_CONT fmt, ##args);                  \
 169         else                                                    \
 170                 if (m)                                          \
 171                         seq_printf(m, fmt, ##args);             \
 172 })
 173 
 174 /*
 175  * Print a readable form of a pgprot_t to the seq_file
 176  */
 177 static void printk_prot(struct seq_file *m, pgprot_t prot, int level, bool dmsg)
 178 {
 179         pgprotval_t pr = pgprot_val(prot);
 180         static const char * const level_name[] =
 181                 { "cr3", "pgd", "p4d", "pud", "pmd", "pte" };
 182 
 183         if (!(pr & _PAGE_PRESENT)) {
 184                 /* Not present */
 185                 pt_dump_cont_printf(m, dmsg, "                              ");
 186         } else {
 187                 if (pr & _PAGE_USER)
 188                         pt_dump_cont_printf(m, dmsg, "USR ");
 189                 else
 190                         pt_dump_cont_printf(m, dmsg, "    ");
 191                 if (pr & _PAGE_RW)
 192                         pt_dump_cont_printf(m, dmsg, "RW ");
 193                 else
 194                         pt_dump_cont_printf(m, dmsg, "ro ");
 195                 if (pr & _PAGE_PWT)
 196                         pt_dump_cont_printf(m, dmsg, "PWT ");
 197                 else
 198                         pt_dump_cont_printf(m, dmsg, "    ");
 199                 if (pr & _PAGE_PCD)
 200                         pt_dump_cont_printf(m, dmsg, "PCD ");
 201                 else
 202                         pt_dump_cont_printf(m, dmsg, "    ");
 203 
 204                 /* Bit 7 has a different meaning on level 3 vs 4 */
 205                 if (level <= 4 && pr & _PAGE_PSE)
 206                         pt_dump_cont_printf(m, dmsg, "PSE ");
 207                 else
 208                         pt_dump_cont_printf(m, dmsg, "    ");
 209                 if ((level == 5 && pr & _PAGE_PAT) ||
 210                     ((level == 4 || level == 3) && pr & _PAGE_PAT_LARGE))
 211                         pt_dump_cont_printf(m, dmsg, "PAT ");
 212                 else
 213                         pt_dump_cont_printf(m, dmsg, "    ");
 214                 if (pr & _PAGE_GLOBAL)
 215                         pt_dump_cont_printf(m, dmsg, "GLB ");
 216                 else
 217                         pt_dump_cont_printf(m, dmsg, "    ");
 218                 if (pr & _PAGE_NX)
 219                         pt_dump_cont_printf(m, dmsg, "NX ");
 220                 else
 221                         pt_dump_cont_printf(m, dmsg, "x  ");
 222         }
 223         pt_dump_cont_printf(m, dmsg, "%s\n", level_name[level]);
 224 }
 225 
 226 /*
 227  * On 64 bits, sign-extend the 48 bit address to 64 bit
 228  */
 229 static unsigned long normalize_addr(unsigned long u)
 230 {
 231         int shift;
 232         if (!IS_ENABLED(CONFIG_X86_64))
 233                 return u;
 234 
 235         shift = 64 - (__VIRTUAL_MASK_SHIFT + 1);
 236         return (signed long)(u << shift) >> shift;
 237 }
 238 
 239 static void note_wx(struct pg_state *st)
 240 {
 241         unsigned long npages;
 242 
 243         npages = (st->current_address - st->start_address) / PAGE_SIZE;
 244 
 245 #ifdef CONFIG_PCI_BIOS
 246         /*
 247          * If PCI BIOS is enabled, the PCI BIOS area is forced to WX.
 248          * Inform about it, but avoid the warning.
 249          */
 250         if (pcibios_enabled && st->start_address >= PAGE_OFFSET + BIOS_BEGIN &&
 251             st->current_address <= PAGE_OFFSET + BIOS_END) {
 252                 pr_warn_once("x86/mm: PCI BIOS W+X mapping %lu pages\n", npages);
 253                 return;
 254         }
 255 #endif
 256         /* Account the WX pages */
 257         st->wx_pages += npages;
 258         WARN_ONCE(__supported_pte_mask & _PAGE_NX,
 259                   "x86/mm: Found insecure W+X mapping at address %pS\n",
 260                   (void *)st->start_address);
 261 }
 262 
 263 /*
 264  * This function gets called on a break in a continuous series
 265  * of PTE entries; the next one is different so we need to
 266  * print what we collected so far.
 267  */
 268 static void note_page(struct seq_file *m, struct pg_state *st,
 269                       pgprot_t new_prot, pgprotval_t new_eff, int level)
 270 {
 271         pgprotval_t prot, cur, eff;
 272         static const char units[] = "BKMGTPE";
 273 
 274         /*
 275          * If we have a "break" in the series, we need to flush the state that
 276          * we have now. "break" is either changing perms, levels or
 277          * address space marker.
 278          */
 279         prot = pgprot_val(new_prot);
 280         cur = pgprot_val(st->current_prot);
 281         eff = st->effective_prot;
 282 
 283         if (!st->level) {
 284                 /* First entry */
 285                 st->current_prot = new_prot;
 286                 st->effective_prot = new_eff;
 287                 st->level = level;
 288                 st->marker = address_markers;
 289                 st->lines = 0;
 290                 pt_dump_seq_printf(m, st->to_dmesg, "---[ %s ]---\n",
 291                                    st->marker->name);
 292         } else if (prot != cur || new_eff != eff || level != st->level ||
 293                    st->current_address >= st->marker[1].start_address) {
 294                 const char *unit = units;
 295                 unsigned long delta;
 296                 int width = sizeof(unsigned long) * 2;
 297 
 298                 if (st->check_wx && (eff & _PAGE_RW) && !(eff & _PAGE_NX))
 299                         note_wx(st);
 300 
 301                 /*
 302                  * Now print the actual finished series
 303                  */
 304                 if (!st->marker->max_lines ||
 305                     st->lines < st->marker->max_lines) {
 306                         pt_dump_seq_printf(m, st->to_dmesg,
 307                                            "0x%0*lx-0x%0*lx   ",
 308                                            width, st->start_address,
 309                                            width, st->current_address);
 310 
 311                         delta = st->current_address - st->start_address;
 312                         while (!(delta & 1023) && unit[1]) {
 313                                 delta >>= 10;
 314                                 unit++;
 315                         }
 316                         pt_dump_cont_printf(m, st->to_dmesg, "%9lu%c ",
 317                                             delta, *unit);
 318                         printk_prot(m, st->current_prot, st->level,
 319                                     st->to_dmesg);
 320                 }
 321                 st->lines++;
 322 
 323                 /*
 324                  * We print markers for special areas of address space,
 325                  * such as the start of vmalloc space etc.
 326                  * This helps in the interpretation.
 327                  */
 328                 if (st->current_address >= st->marker[1].start_address) {
 329                         if (st->marker->max_lines &&
 330                             st->lines > st->marker->max_lines) {
 331                                 unsigned long nskip =
 332                                         st->lines - st->marker->max_lines;
 333                                 pt_dump_seq_printf(m, st->to_dmesg,
 334                                                    "... %lu entr%s skipped ... \n",
 335                                                    nskip,
 336                                                    nskip == 1 ? "y" : "ies");
 337                         }
 338                         st->marker++;
 339                         st->lines = 0;
 340                         pt_dump_seq_printf(m, st->to_dmesg, "---[ %s ]---\n",
 341                                            st->marker->name);
 342                 }
 343 
 344                 st->start_address = st->current_address;
 345                 st->current_prot = new_prot;
 346                 st->effective_prot = new_eff;
 347                 st->level = level;
 348         }
 349 }
 350 
 351 static inline pgprotval_t effective_prot(pgprotval_t prot1, pgprotval_t prot2)
 352 {
 353         return (prot1 & prot2 & (_PAGE_USER | _PAGE_RW)) |
 354                ((prot1 | prot2) & _PAGE_NX);
 355 }
 356 
 357 static void walk_pte_level(struct seq_file *m, struct pg_state *st, pmd_t addr,
 358                            pgprotval_t eff_in, unsigned long P)
 359 {
 360         int i;
 361         pte_t *pte;
 362         pgprotval_t prot, eff;
 363 
 364         for (i = 0; i < PTRS_PER_PTE; i++) {
 365                 st->current_address = normalize_addr(P + i * PTE_LEVEL_MULT);
 366                 pte = pte_offset_map(&addr, st->current_address);
 367                 prot = pte_flags(*pte);
 368                 eff = effective_prot(eff_in, prot);
 369                 note_page(m, st, __pgprot(prot), eff, 5);
 370                 pte_unmap(pte);
 371         }
 372 }
 373 #ifdef CONFIG_KASAN
 374 
 375 /*
 376  * This is an optimization for KASAN=y case. Since all kasan page tables
 377  * eventually point to the kasan_early_shadow_page we could call note_page()
 378  * right away without walking through lower level page tables. This saves
 379  * us dozens of seconds (minutes for 5-level config) while checking for
 380  * W+X mapping or reading kernel_page_tables debugfs file.
 381  */
 382 static inline bool kasan_page_table(struct seq_file *m, struct pg_state *st,
 383                                 void *pt)
 384 {
 385         if (__pa(pt) == __pa(kasan_early_shadow_pmd) ||
 386             (pgtable_l5_enabled() &&
 387                         __pa(pt) == __pa(kasan_early_shadow_p4d)) ||
 388             __pa(pt) == __pa(kasan_early_shadow_pud)) {
 389                 pgprotval_t prot = pte_flags(kasan_early_shadow_pte[0]);
 390                 note_page(m, st, __pgprot(prot), 0, 5);
 391                 return true;
 392         }
 393         return false;
 394 }
 395 #else
 396 static inline bool kasan_page_table(struct seq_file *m, struct pg_state *st,
 397                                 void *pt)
 398 {
 399         return false;
 400 }
 401 #endif
 402 
 403 #if PTRS_PER_PMD > 1
 404 
 405 static void walk_pmd_level(struct seq_file *m, struct pg_state *st, pud_t addr,
 406                            pgprotval_t eff_in, unsigned long P)
 407 {
 408         int i;
 409         pmd_t *start, *pmd_start;
 410         pgprotval_t prot, eff;
 411 
 412         pmd_start = start = (pmd_t *)pud_page_vaddr(addr);
 413         for (i = 0; i < PTRS_PER_PMD; i++) {
 414                 st->current_address = normalize_addr(P + i * PMD_LEVEL_MULT);
 415                 if (!pmd_none(*start)) {
 416                         prot = pmd_flags(*start);
 417                         eff = effective_prot(eff_in, prot);
 418                         if (pmd_large(*start) || !pmd_present(*start)) {
 419                                 note_page(m, st, __pgprot(prot), eff, 4);
 420                         } else if (!kasan_page_table(m, st, pmd_start)) {
 421                                 walk_pte_level(m, st, *start, eff,
 422                                                P + i * PMD_LEVEL_MULT);
 423                         }
 424                 } else
 425                         note_page(m, st, __pgprot(0), 0, 4);
 426                 start++;
 427         }
 428 }
 429 
 430 #else
 431 #define walk_pmd_level(m,s,a,e,p) walk_pte_level(m,s,__pmd(pud_val(a)),e,p)
 432 #define pud_large(a) pmd_large(__pmd(pud_val(a)))
 433 #define pud_none(a)  pmd_none(__pmd(pud_val(a)))
 434 #endif
 435 
 436 #if PTRS_PER_PUD > 1
 437 
 438 static void walk_pud_level(struct seq_file *m, struct pg_state *st, p4d_t addr,
 439                            pgprotval_t eff_in, unsigned long P)
 440 {
 441         int i;
 442         pud_t *start, *pud_start;
 443         pgprotval_t prot, eff;
 444 
 445         pud_start = start = (pud_t *)p4d_page_vaddr(addr);
 446 
 447         for (i = 0; i < PTRS_PER_PUD; i++) {
 448                 st->current_address = normalize_addr(P + i * PUD_LEVEL_MULT);
 449                 if (!pud_none(*start)) {
 450                         prot = pud_flags(*start);
 451                         eff = effective_prot(eff_in, prot);
 452                         if (pud_large(*start) || !pud_present(*start)) {
 453                                 note_page(m, st, __pgprot(prot), eff, 3);
 454                         } else if (!kasan_page_table(m, st, pud_start)) {
 455                                 walk_pmd_level(m, st, *start, eff,
 456                                                P + i * PUD_LEVEL_MULT);
 457                         }
 458                 } else
 459                         note_page(m, st, __pgprot(0), 0, 3);
 460 
 461                 start++;
 462         }
 463 }
 464 
 465 #else
 466 #define walk_pud_level(m,s,a,e,p) walk_pmd_level(m,s,__pud(p4d_val(a)),e,p)
 467 #define p4d_large(a) pud_large(__pud(p4d_val(a)))
 468 #define p4d_none(a)  pud_none(__pud(p4d_val(a)))
 469 #endif
 470 
 471 static void walk_p4d_level(struct seq_file *m, struct pg_state *st, pgd_t addr,
 472                            pgprotval_t eff_in, unsigned long P)
 473 {
 474         int i;
 475         p4d_t *start, *p4d_start;
 476         pgprotval_t prot, eff;
 477 
 478         if (PTRS_PER_P4D == 1)
 479                 return walk_pud_level(m, st, __p4d(pgd_val(addr)), eff_in, P);
 480 
 481         p4d_start = start = (p4d_t *)pgd_page_vaddr(addr);
 482 
 483         for (i = 0; i < PTRS_PER_P4D; i++) {
 484                 st->current_address = normalize_addr(P + i * P4D_LEVEL_MULT);
 485                 if (!p4d_none(*start)) {
 486                         prot = p4d_flags(*start);
 487                         eff = effective_prot(eff_in, prot);
 488                         if (p4d_large(*start) || !p4d_present(*start)) {
 489                                 note_page(m, st, __pgprot(prot), eff, 2);
 490                         } else if (!kasan_page_table(m, st, p4d_start)) {
 491                                 walk_pud_level(m, st, *start, eff,
 492                                                P + i * P4D_LEVEL_MULT);
 493                         }
 494                 } else
 495                         note_page(m, st, __pgprot(0), 0, 2);
 496 
 497                 start++;
 498         }
 499 }
 500 
 501 #define pgd_large(a) (pgtable_l5_enabled() ? pgd_large(a) : p4d_large(__p4d(pgd_val(a))))
 502 #define pgd_none(a)  (pgtable_l5_enabled() ? pgd_none(a) : p4d_none(__p4d(pgd_val(a))))
 503 
 504 static inline bool is_hypervisor_range(int idx)
 505 {
 506 #ifdef CONFIG_X86_64
 507         /*
 508          * A hole in the beginning of kernel address space reserved
 509          * for a hypervisor.
 510          */
 511         return  (idx >= pgd_index(GUARD_HOLE_BASE_ADDR)) &&
 512                 (idx <  pgd_index(GUARD_HOLE_END_ADDR));
 513 #else
 514         return false;
 515 #endif
 516 }
 517 
 518 static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd,
 519                                        bool checkwx, bool dmesg)
 520 {
 521         pgd_t *start = INIT_PGD;
 522         pgprotval_t prot, eff;
 523         int i;
 524         struct pg_state st = {};
 525 
 526         if (pgd) {
 527                 start = pgd;
 528                 st.to_dmesg = dmesg;
 529         }
 530 
 531         st.check_wx = checkwx;
 532         if (checkwx)
 533                 st.wx_pages = 0;
 534 
 535         for (i = 0; i < PTRS_PER_PGD; i++) {
 536                 st.current_address = normalize_addr(i * PGD_LEVEL_MULT);
 537                 if (!pgd_none(*start) && !is_hypervisor_range(i)) {
 538                         prot = pgd_flags(*start);
 539 #ifdef CONFIG_X86_PAE
 540                         eff = _PAGE_USER | _PAGE_RW;
 541 #else
 542                         eff = prot;
 543 #endif
 544                         if (pgd_large(*start) || !pgd_present(*start)) {
 545                                 note_page(m, &st, __pgprot(prot), eff, 1);
 546                         } else {
 547                                 walk_p4d_level(m, &st, *start, eff,
 548                                                i * PGD_LEVEL_MULT);
 549                         }
 550                 } else
 551                         note_page(m, &st, __pgprot(0), 0, 1);
 552 
 553                 cond_resched();
 554                 start++;
 555         }
 556 
 557         /* Flush out the last page */
 558         st.current_address = normalize_addr(PTRS_PER_PGD*PGD_LEVEL_MULT);
 559         note_page(m, &st, __pgprot(0), 0, 0);
 560         if (!checkwx)
 561                 return;
 562         if (st.wx_pages)
 563                 pr_info("x86/mm: Checked W+X mappings: FAILED, %lu W+X pages found.\n",
 564                         st.wx_pages);
 565         else
 566                 pr_info("x86/mm: Checked W+X mappings: passed, no W+X pages found.\n");
 567 }
 568 
 569 void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd)
 570 {
 571         ptdump_walk_pgd_level_core(m, pgd, false, true);
 572 }
 573 
 574 void ptdump_walk_pgd_level_debugfs(struct seq_file *m, pgd_t *pgd, bool user)
 575 {
 576 #ifdef CONFIG_PAGE_TABLE_ISOLATION
 577         if (user && boot_cpu_has(X86_FEATURE_PTI))
 578                 pgd = kernel_to_user_pgdp(pgd);
 579 #endif
 580         ptdump_walk_pgd_level_core(m, pgd, false, false);
 581 }
 582 EXPORT_SYMBOL_GPL(ptdump_walk_pgd_level_debugfs);
 583 
 584 void ptdump_walk_user_pgd_level_checkwx(void)
 585 {
 586 #ifdef CONFIG_PAGE_TABLE_ISOLATION
 587         pgd_t *pgd = INIT_PGD;
 588 
 589         if (!(__supported_pte_mask & _PAGE_NX) ||
 590             !boot_cpu_has(X86_FEATURE_PTI))
 591                 return;
 592 
 593         pr_info("x86/mm: Checking user space page tables\n");
 594         pgd = kernel_to_user_pgdp(pgd);
 595         ptdump_walk_pgd_level_core(NULL, pgd, true, false);
 596 #endif
 597 }
 598 
 599 void ptdump_walk_pgd_level_checkwx(void)
 600 {
 601         ptdump_walk_pgd_level_core(NULL, NULL, true, false);
 602 }
 603 
 604 static int __init pt_dump_init(void)
 605 {
 606         /*
 607          * Various markers are not compile-time constants, so assign them
 608          * here.
 609          */
 610 #ifdef CONFIG_X86_64
 611         address_markers[LOW_KERNEL_NR].start_address = PAGE_OFFSET;
 612         address_markers[VMALLOC_START_NR].start_address = VMALLOC_START;
 613         address_markers[VMEMMAP_START_NR].start_address = VMEMMAP_START;
 614 #ifdef CONFIG_MODIFY_LDT_SYSCALL
 615         address_markers[LDT_NR].start_address = LDT_BASE_ADDR;
 616 #endif
 617 #ifdef CONFIG_KASAN
 618         address_markers[KASAN_SHADOW_START_NR].start_address = KASAN_SHADOW_START;
 619         address_markers[KASAN_SHADOW_END_NR].start_address = KASAN_SHADOW_END;
 620 #endif
 621 #endif
 622 #ifdef CONFIG_X86_32
 623         address_markers[VMALLOC_START_NR].start_address = VMALLOC_START;
 624         address_markers[VMALLOC_END_NR].start_address = VMALLOC_END;
 625 # ifdef CONFIG_HIGHMEM
 626         address_markers[PKMAP_BASE_NR].start_address = PKMAP_BASE;
 627 # endif
 628         address_markers[FIXADDR_START_NR].start_address = FIXADDR_START;
 629         address_markers[CPU_ENTRY_AREA_NR].start_address = CPU_ENTRY_AREA_BASE;
 630 # ifdef CONFIG_MODIFY_LDT_SYSCALL
 631         address_markers[LDT_NR].start_address = LDT_BASE_ADDR;
 632 # endif
 633 #endif
 634         return 0;
 635 }
 636 __initcall(pt_dump_init);
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root/arch/x86/mm/dump_pagetables.c

DEFINITIONS
