linux/arch/um/kernel/tlb.c
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   1/*
   2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3 * Licensed under the GPL
   4 */
   5
   6#include <linux/mm.h>
   7#include <linux/module.h>
   8#include <linux/sched.h>
   9#include <asm/pgtable.h>
  10#include <asm/tlbflush.h>
  11#include "as-layout.h"
  12#include "mem_user.h"
  13#include "os.h"
  14#include "skas.h"
  15
  16struct host_vm_change {
  17        struct host_vm_op {
  18                enum { NONE, MMAP, MUNMAP, MPROTECT } type;
  19                union {
  20                        struct {
  21                                unsigned long addr;
  22                                unsigned long len;
  23                                unsigned int prot;
  24                                int fd;
  25                                __u64 offset;
  26                        } mmap;
  27                        struct {
  28                                unsigned long addr;
  29                                unsigned long len;
  30                        } munmap;
  31                        struct {
  32                                unsigned long addr;
  33                                unsigned long len;
  34                                unsigned int prot;
  35                        } mprotect;
  36                } u;
  37        } ops[1];
  38        int index;
  39        struct mm_id *id;
  40        void *data;
  41        int force;
  42};
  43
  44#define INIT_HVC(mm, force) \
  45        ((struct host_vm_change) \
  46         { .ops         = { { .type = NONE } }, \
  47           .id          = &mm->context.id, \
  48           .data        = NULL, \
  49           .index       = 0, \
  50           .force       = force })
  51
  52static int do_ops(struct host_vm_change *hvc, int end,
  53                  int finished)
  54{
  55        struct host_vm_op *op;
  56        int i, ret = 0;
  57
  58        for (i = 0; i < end && !ret; i++) {
  59                op = &hvc->ops[i];
  60                switch (op->type) {
  61                case MMAP:
  62                        ret = map(hvc->id, op->u.mmap.addr, op->u.mmap.len,
  63                                  op->u.mmap.prot, op->u.mmap.fd,
  64                                  op->u.mmap.offset, finished, &hvc->data);
  65                        break;
  66                case MUNMAP:
  67                        ret = unmap(hvc->id, op->u.munmap.addr,
  68                                    op->u.munmap.len, finished, &hvc->data);
  69                        break;
  70                case MPROTECT:
  71                        ret = protect(hvc->id, op->u.mprotect.addr,
  72                                      op->u.mprotect.len, op->u.mprotect.prot,
  73                                      finished, &hvc->data);
  74                        break;
  75                default:
  76                        printk(KERN_ERR "Unknown op type %d in do_ops\n",
  77                               op->type);
  78                        break;
  79                }
  80        }
  81
  82        return ret;
  83}
  84
  85static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
  86                    unsigned int prot, struct host_vm_change *hvc)
  87{
  88        __u64 offset;
  89        struct host_vm_op *last;
  90        int fd, ret = 0;
  91
  92        fd = phys_mapping(phys, &offset);
  93        if (hvc->index != 0) {
  94                last = &hvc->ops[hvc->index - 1];
  95                if ((last->type == MMAP) &&
  96                   (last->u.mmap.addr + last->u.mmap.len == virt) &&
  97                   (last->u.mmap.prot == prot) && (last->u.mmap.fd == fd) &&
  98                   (last->u.mmap.offset + last->u.mmap.len == offset)) {
  99                        last->u.mmap.len += len;
 100                        return 0;
 101                }
 102        }
 103
 104        if (hvc->index == ARRAY_SIZE(hvc->ops)) {
 105                ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
 106                hvc->index = 0;
 107        }
 108
 109        hvc->ops[hvc->index++] = ((struct host_vm_op)
 110                                  { .type       = MMAP,
 111                                    .u = { .mmap = { .addr      = virt,
 112                                                     .len       = len,
 113                                                     .prot      = prot,
 114                                                     .fd        = fd,
 115                                                     .offset    = offset }
 116                           } });
 117        return ret;
 118}
 119
 120static int add_munmap(unsigned long addr, unsigned long len,
 121                      struct host_vm_change *hvc)
 122{
 123        struct host_vm_op *last;
 124        int ret = 0;
 125
 126        if (hvc->index != 0) {
 127                last = &hvc->ops[hvc->index - 1];
 128                if ((last->type == MUNMAP) &&
 129                   (last->u.munmap.addr + last->u.mmap.len == addr)) {
 130                        last->u.munmap.len += len;
 131                        return 0;
 132                }
 133        }
 134
 135        if (hvc->index == ARRAY_SIZE(hvc->ops)) {
 136                ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
 137                hvc->index = 0;
 138        }
 139
 140        hvc->ops[hvc->index++] = ((struct host_vm_op)
 141                                  { .type       = MUNMAP,
 142                                    .u = { .munmap = { .addr    = addr,
 143                                                       .len     = len } } });
 144        return ret;
 145}
 146
 147static int add_mprotect(unsigned long addr, unsigned long len,
 148                        unsigned int prot, struct host_vm_change *hvc)
 149{
 150        struct host_vm_op *last;
 151        int ret = 0;
 152
 153        if (hvc->index != 0) {
 154                last = &hvc->ops[hvc->index - 1];
 155                if ((last->type == MPROTECT) &&
 156                   (last->u.mprotect.addr + last->u.mprotect.len == addr) &&
 157                   (last->u.mprotect.prot == prot)) {
 158                        last->u.mprotect.len += len;
 159                        return 0;
 160                }
 161        }
 162
 163        if (hvc->index == ARRAY_SIZE(hvc->ops)) {
 164                ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
 165                hvc->index = 0;
 166        }
 167
 168        hvc->ops[hvc->index++] = ((struct host_vm_op)
 169                                  { .type       = MPROTECT,
 170                                    .u = { .mprotect = { .addr  = addr,
 171                                                         .len   = len,
 172                                                         .prot  = prot } } });
 173        return ret;
 174}
 175
 176#define ADD_ROUND(n, inc) (((n) + (inc)) & ~((inc) - 1))
 177
 178static inline int update_pte_range(pmd_t *pmd, unsigned long addr,
 179                                   unsigned long end,
 180                                   struct host_vm_change *hvc)
 181{
 182        pte_t *pte;
 183        int r, w, x, prot, ret = 0;
 184
 185        pte = pte_offset_kernel(pmd, addr);
 186        do {
 187                if ((addr >= STUB_START) && (addr < STUB_END))
 188                        continue;
 189
 190                r = pte_read(*pte);
 191                w = pte_write(*pte);
 192                x = pte_exec(*pte);
 193                if (!pte_young(*pte)) {
 194                        r = 0;
 195                        w = 0;
 196                } else if (!pte_dirty(*pte))
 197                        w = 0;
 198
 199                prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
 200                        (x ? UM_PROT_EXEC : 0));
 201                if (hvc->force || pte_newpage(*pte)) {
 202                        if (pte_present(*pte))
 203                                ret = add_mmap(addr, pte_val(*pte) & PAGE_MASK,
 204                                               PAGE_SIZE, prot, hvc);
 205                        else
 206                                ret = add_munmap(addr, PAGE_SIZE, hvc);
 207                } else if (pte_newprot(*pte))
 208                        ret = add_mprotect(addr, PAGE_SIZE, prot, hvc);
 209                *pte = pte_mkuptodate(*pte);
 210        } while (pte++, addr += PAGE_SIZE, ((addr < end) && !ret));
 211        return ret;
 212}
 213
 214static inline int update_pmd_range(pud_t *pud, unsigned long addr,
 215                                   unsigned long end,
 216                                   struct host_vm_change *hvc)
 217{
 218        pmd_t *pmd;
 219        unsigned long next;
 220        int ret = 0;
 221
 222        pmd = pmd_offset(pud, addr);
 223        do {
 224                next = pmd_addr_end(addr, end);
 225                if (!pmd_present(*pmd)) {
 226                        if (hvc->force || pmd_newpage(*pmd)) {
 227                                ret = add_munmap(addr, next - addr, hvc);
 228                                pmd_mkuptodate(*pmd);
 229                        }
 230                }
 231                else ret = update_pte_range(pmd, addr, next, hvc);
 232        } while (pmd++, addr = next, ((addr < end) && !ret));
 233        return ret;
 234}
 235
 236static inline int update_pud_range(pgd_t *pgd, unsigned long addr,
 237                                   unsigned long end,
 238                                   struct host_vm_change *hvc)
 239{
 240        pud_t *pud;
 241        unsigned long next;
 242        int ret = 0;
 243
 244        pud = pud_offset(pgd, addr);
 245        do {
 246                next = pud_addr_end(addr, end);
 247                if (!pud_present(*pud)) {
 248                        if (hvc->force || pud_newpage(*pud)) {
 249                                ret = add_munmap(addr, next - addr, hvc);
 250                                pud_mkuptodate(*pud);
 251                        }
 252                }
 253                else ret = update_pmd_range(pud, addr, next, hvc);
 254        } while (pud++, addr = next, ((addr < end) && !ret));
 255        return ret;
 256}
 257
 258void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
 259                      unsigned long end_addr, int force)
 260{
 261        pgd_t *pgd;
 262        struct host_vm_change hvc;
 263        unsigned long addr = start_addr, next;
 264        int ret = 0;
 265
 266        hvc = INIT_HVC(mm, force);
 267        pgd = pgd_offset(mm, addr);
 268        do {
 269                next = pgd_addr_end(addr, end_addr);
 270                if (!pgd_present(*pgd)) {
 271                        if (force || pgd_newpage(*pgd)) {
 272                                ret = add_munmap(addr, next - addr, &hvc);
 273                                pgd_mkuptodate(*pgd);
 274                        }
 275                }
 276                else ret = update_pud_range(pgd, addr, next, &hvc);
 277        } while (pgd++, addr = next, ((addr < end_addr) && !ret));
 278
 279        if (!ret)
 280                ret = do_ops(&hvc, hvc.index, 1);
 281
 282        /* This is not an else because ret is modified above */
 283        if (ret) {
 284                printk(KERN_ERR "fix_range_common: failed, killing current "
 285                       "process\n");
 286                force_sig(SIGKILL, current);
 287        }
 288}
 289
 290static int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
 291{
 292        struct mm_struct *mm;
 293        pgd_t *pgd;
 294        pud_t *pud;
 295        pmd_t *pmd;
 296        pte_t *pte;
 297        unsigned long addr, last;
 298        int updated = 0, err;
 299
 300        mm = &init_mm;
 301        for (addr = start; addr < end;) {
 302                pgd = pgd_offset(mm, addr);
 303                if (!pgd_present(*pgd)) {
 304                        last = ADD_ROUND(addr, PGDIR_SIZE);
 305                        if (last > end)
 306                                last = end;
 307                        if (pgd_newpage(*pgd)) {
 308                                updated = 1;
 309                                err = os_unmap_memory((void *) addr,
 310                                                      last - addr);
 311                                if (err < 0)
 312                                        panic("munmap failed, errno = %d\n",
 313                                              -err);
 314                        }
 315                        addr = last;
 316                        continue;
 317                }
 318
 319                pud = pud_offset(pgd, addr);
 320                if (!pud_present(*pud)) {
 321                        last = ADD_ROUND(addr, PUD_SIZE);
 322                        if (last > end)
 323                                last = end;
 324                        if (pud_newpage(*pud)) {
 325                                updated = 1;
 326                                err = os_unmap_memory((void *) addr,
 327                                                      last - addr);
 328                                if (err < 0)
 329                                        panic("munmap failed, errno = %d\n",
 330                                              -err);
 331                        }
 332                        addr = last;
 333                        continue;
 334                }
 335
 336                pmd = pmd_offset(pud, addr);
 337                if (!pmd_present(*pmd)) {
 338                        last = ADD_ROUND(addr, PMD_SIZE);
 339                        if (last > end)
 340                                last = end;
 341                        if (pmd_newpage(*pmd)) {
 342                                updated = 1;
 343                                err = os_unmap_memory((void *) addr,
 344                                                      last - addr);
 345                                if (err < 0)
 346                                        panic("munmap failed, errno = %d\n",
 347                                              -err);
 348                        }
 349                        addr = last;
 350                        continue;
 351                }
 352
 353                pte = pte_offset_kernel(pmd, addr);
 354                if (!pte_present(*pte) || pte_newpage(*pte)) {
 355                        updated = 1;
 356                        err = os_unmap_memory((void *) addr,
 357                                              PAGE_SIZE);
 358                        if (err < 0)
 359                                panic("munmap failed, errno = %d\n",
 360                                      -err);
 361                        if (pte_present(*pte))
 362                                map_memory(addr,
 363                                           pte_val(*pte) & PAGE_MASK,
 364                                           PAGE_SIZE, 1, 1, 1);
 365                }
 366                else if (pte_newprot(*pte)) {
 367                        updated = 1;
 368                        os_protect_memory((void *) addr, PAGE_SIZE, 1, 1, 1);
 369                }
 370                addr += PAGE_SIZE;
 371        }
 372        return updated;
 373}
 374
 375void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
 376{
 377        pgd_t *pgd;
 378        pud_t *pud;
 379        pmd_t *pmd;
 380        pte_t *pte;
 381        struct mm_struct *mm = vma->vm_mm;
 382        void *flush = NULL;
 383        int r, w, x, prot, err = 0;
 384        struct mm_id *mm_id;
 385
 386        address &= PAGE_MASK;
 387        pgd = pgd_offset(mm, address);
 388        if (!pgd_present(*pgd))
 389                goto kill;
 390
 391        pud = pud_offset(pgd, address);
 392        if (!pud_present(*pud))
 393                goto kill;
 394
 395        pmd = pmd_offset(pud, address);
 396        if (!pmd_present(*pmd))
 397                goto kill;
 398
 399        pte = pte_offset_kernel(pmd, address);
 400
 401        r = pte_read(*pte);
 402        w = pte_write(*pte);
 403        x = pte_exec(*pte);
 404        if (!pte_young(*pte)) {
 405                r = 0;
 406                w = 0;
 407        } else if (!pte_dirty(*pte)) {
 408                w = 0;
 409        }
 410
 411        mm_id = &mm->context.id;
 412        prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
 413                (x ? UM_PROT_EXEC : 0));
 414        if (pte_newpage(*pte)) {
 415                if (pte_present(*pte)) {
 416                        unsigned long long offset;
 417                        int fd;
 418
 419                        fd = phys_mapping(pte_val(*pte) & PAGE_MASK, &offset);
 420                        err = map(mm_id, address, PAGE_SIZE, prot, fd, offset,
 421                                  1, &flush);
 422                }
 423                else err = unmap(mm_id, address, PAGE_SIZE, 1, &flush);
 424        }
 425        else if (pte_newprot(*pte))
 426                err = protect(mm_id, address, PAGE_SIZE, prot, 1, &flush);
 427
 428        if (err)
 429                goto kill;
 430
 431        *pte = pte_mkuptodate(*pte);
 432
 433        return;
 434
 435kill:
 436        printk(KERN_ERR "Failed to flush page for address 0x%lx\n", address);
 437        force_sig(SIGKILL, current);
 438}
 439
 440pgd_t *pgd_offset_proc(struct mm_struct *mm, unsigned long address)
 441{
 442        return pgd_offset(mm, address);
 443}
 444
 445pud_t *pud_offset_proc(pgd_t *pgd, unsigned long address)
 446{
 447        return pud_offset(pgd, address);
 448}
 449
 450pmd_t *pmd_offset_proc(pud_t *pud, unsigned long address)
 451{
 452        return pmd_offset(pud, address);
 453}
 454
 455pte_t *pte_offset_proc(pmd_t *pmd, unsigned long address)
 456{
 457        return pte_offset_kernel(pmd, address);
 458}
 459
 460pte_t *addr_pte(struct task_struct *task, unsigned long addr)
 461{
 462        pgd_t *pgd = pgd_offset(task->mm, addr);
 463        pud_t *pud = pud_offset(pgd, addr);
 464        pmd_t *pmd = pmd_offset(pud, addr);
 465
 466        return pte_offset_map(pmd, addr);
 467}
 468
 469void flush_tlb_all(void)
 470{
 471        flush_tlb_mm(current->mm);
 472}
 473
 474void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 475{
 476        flush_tlb_kernel_range_common(start, end);
 477}
 478
 479void flush_tlb_kernel_vm(void)
 480{
 481        flush_tlb_kernel_range_common(start_vm, end_vm);
 482}
 483
 484void __flush_tlb_one(unsigned long addr)
 485{
 486        flush_tlb_kernel_range_common(addr, addr + PAGE_SIZE);
 487}
 488
 489static void fix_range(struct mm_struct *mm, unsigned long start_addr,
 490                      unsigned long end_addr, int force)
 491{
 492        fix_range_common(mm, start_addr, end_addr, force);
 493}
 494
 495void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 496                     unsigned long end)
 497{
 498        if (vma->vm_mm == NULL)
 499                flush_tlb_kernel_range_common(start, end);
 500        else fix_range(vma->vm_mm, start, end, 0);
 501}
 502EXPORT_SYMBOL(flush_tlb_range);
 503
 504void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
 505                        unsigned long end)
 506{
 507        /*
 508         * Don't bother flushing if this address space is about to be
 509         * destroyed.
 510         */
 511        if (atomic_read(&mm->mm_users) == 0)
 512                return;
 513
 514        fix_range(mm, start, end, 0);
 515}
 516
 517void flush_tlb_mm(struct mm_struct *mm)
 518{
 519        struct vm_area_struct *vma = mm->mmap;
 520
 521        while (vma != NULL) {
 522                fix_range(mm, vma->vm_start, vma->vm_end, 0);
 523                vma = vma->vm_next;
 524        }
 525}
 526
 527void force_flush_all(void)
 528{
 529        struct mm_struct *mm = current->mm;
 530        struct vm_area_struct *vma = mm->mmap;
 531
 532        while (vma != NULL) {
 533                fix_range(mm, vma->vm_start, vma->vm_end, 1);
 534                vma = vma->vm_next;
 535        }
 536}
 537
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