SAFE public projects git trees. - safe/jmp/linux-2.6/blob - arch/um/kernel/tlb.c

   1 /*
   2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/mm.h"
   7 #include "asm/page.h"
   8 #include "asm/pgalloc.h"
   9 #include "asm/pgtable.h"
  10 #include "asm/tlbflush.h"
  11 #include "as-layout.h"
  12 #include "tlb.h"
  13 #include "mem.h"
  14 #include "mem_user.h"
  15 #include "os.h"
  16 #include "skas.h"
  17
  18 static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
  19                     unsigned int prot, struct host_vm_op *ops, int *index,
  20                     int last_filled, union mm_context *mmu, void **flush,
  21                     int (*do_ops)(union mm_context *, struct host_vm_op *,
  22                                   int, int, void **))
  23 {
  24         __u64 offset;
  25         struct host_vm_op *last;
  26         int fd, ret = 0;
  27
  28         fd = phys_mapping(phys, &offset);
  29         if(*index != -1){
  30                 last = &ops[*index];
  31                 if((last->type == MMAP) &&
  32                    (last->u.mmap.addr + last->u.mmap.len == virt) &&
  33                    (last->u.mmap.prot == prot) && (last->u.mmap.fd == fd) &&
  34                    (last->u.mmap.offset + last->u.mmap.len == offset)){
  35                         last->u.mmap.len += len;
  36                         return 0;
  37                 }
  38         }
  39
  40         if(*index == last_filled){
  41                 ret = (*do_ops)(mmu, ops, last_filled, 0, flush);
  42                 *index = -1;
  43         }
  44
  45         ops[++*index] = ((struct host_vm_op) { .type    = MMAP,
  46                                                 .u = { .mmap = {
  47                                                        .addr    = virt,
  48                                                        .len     = len,
  49                                                        .prot    = prot,
  50                                                        .fd      = fd,
  51                                                        .offset  = offset }
  52                            } });
  53         return ret;
  54 }
  55
  56 static int add_munmap(unsigned long addr, unsigned long len,
  57                       struct host_vm_op *ops, int *index, int last_filled,
  58                       union mm_context *mmu, void **flush,
  59                       int (*do_ops)(union mm_context *, struct host_vm_op *,
  60                                     int, int, void **))
  61 {
  62         struct host_vm_op *last;
  63         int ret = 0;
  64
  65         if(*index != -1){
  66                 last = &ops[*index];
  67                 if((last->type == MUNMAP) &&
  68                    (last->u.munmap.addr + last->u.mmap.len == addr)){
  69                         last->u.munmap.len += len;
  70                         return 0;
  71                 }
  72         }
  73
  74         if(*index == last_filled){
  75                 ret = (*do_ops)(mmu, ops, last_filled, 0, flush);
  76                 *index = -1;
  77         }
  78
  79         ops[++*index] = ((struct host_vm_op) { .type    = MUNMAP,
  80                                                .u = { .munmap = {
  81                                                         .addr   = addr,
  82                                                         .len    = len } } });
  83         return ret;
  84 }
  85
  86 static int add_mprotect(unsigned long addr, unsigned long len,
  87                         unsigned int prot, struct host_vm_op *ops, int *index,
  88                         int last_filled, union mm_context *mmu, void **flush,
  89                         int (*do_ops)(union mm_context *, struct host_vm_op *,
  90                                       int, int, void **))
  91 {
  92         struct host_vm_op *last;
  93         int ret = 0;
  94
  95         if(*index != -1){
  96                 last = &ops[*index];
  97                 if((last->type == MPROTECT) &&
  98                    (last->u.mprotect.addr + last->u.mprotect.len == addr) &&
  99                    (last->u.mprotect.prot == prot)){
 100                         last->u.mprotect.len += len;
 101                         return 0;
 102                 }
 103         }
 104
 105         if(*index == last_filled){
 106                 ret = (*do_ops)(mmu, ops, last_filled, 0, flush);
 107                 *index = -1;
 108         }
 109
 110         ops[++*index] = ((struct host_vm_op) { .type    = MPROTECT,
 111                                                .u = { .mprotect = {
 112                                                        .addr    = addr,
 113                                                        .len     = len,
 114                                                        .prot    = prot } } });
 115         return ret;
 116 }
 117
 118 #define ADD_ROUND(n, inc) (((n) + (inc)) & ~((inc) - 1))
 119
 120 static inline int update_pte_range(pmd_t *pmd, unsigned long addr,
 121                                    unsigned long end, struct host_vm_op *ops,
 122                                    int last_op, int *op_index, int force,
 123                                    union mm_context *mmu, void **flush,
 124                                    int (*do_ops)(union mm_context *,
 125                                                  struct host_vm_op *, int, int,
 126                                                  void **))
 127 {
 128         pte_t *pte;
 129         int r, w, x, prot, ret = 0;
 130
 131         pte = pte_offset_kernel(pmd, addr);
 132         do {
 133                 r = pte_read(*pte);
 134                 w = pte_write(*pte);
 135                 x = pte_exec(*pte);
 136                 if (!pte_young(*pte)) {
 137                         r = 0;
 138                         w = 0;
 139                 } else if (!pte_dirty(*pte)) {
 140                         w = 0;
 141                 }
 142                 prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
 143                         (x ? UM_PROT_EXEC : 0));
 144                 if(force || pte_newpage(*pte)){
 145                         if(pte_present(*pte))
 146                                 ret = add_mmap(addr, pte_val(*pte) & PAGE_MASK,
 147                                                PAGE_SIZE, prot, ops, op_index,
 148                                                last_op, mmu, flush, do_ops);
 149                         else ret = add_munmap(addr, PAGE_SIZE, ops, op_index,
 150                                               last_op, mmu, flush, do_ops);
 151                 }
 152                 else if(pte_newprot(*pte))
 153                         ret = add_mprotect(addr, PAGE_SIZE, prot, ops, op_index,
 154                                            last_op, mmu, flush, do_ops);
 155                 *pte = pte_mkuptodate(*pte);
 156         } while (pte++, addr += PAGE_SIZE, ((addr != end) && !ret));
 157         return ret;
 158 }
 159
 160 static inline int update_pmd_range(pud_t *pud, unsigned long addr,
 161                                    unsigned long end, struct host_vm_op *ops,
 162                                    int last_op, int *op_index, int force,
 163                                    union mm_context *mmu, void **flush,
 164                                    int (*do_ops)(union mm_context *,
 165                                                  struct host_vm_op *, int, int,
 166                                                  void **))
 167 {
 168         pmd_t *pmd;
 169         unsigned long next;
 170         int ret = 0;
 171
 172         pmd = pmd_offset(pud, addr);
 173         do {
 174                 next = pmd_addr_end(addr, end);
 175                 if(!pmd_present(*pmd)){
 176                         if(force || pmd_newpage(*pmd)){
 177                                 ret = add_munmap(addr, next - addr, ops,
 178                                                  op_index, last_op, mmu,
 179                                                  flush, do_ops);
 180                                 pmd_mkuptodate(*pmd);
 181                         }
 182                 }
 183                 else ret = update_pte_range(pmd, addr, next, ops, last_op,
 184                                             op_index, force, mmu, flush,
 185                                             do_ops);
 186         } while (pmd++, addr = next, ((addr != end) && !ret));
 187         return ret;
 188 }
 189
 190 static inline int update_pud_range(pgd_t *pgd, unsigned long addr,
 191                                    unsigned long end, struct host_vm_op *ops,
 192                                    int last_op, int *op_index, int force,
 193                                    union mm_context *mmu, void **flush,
 194                                    int (*do_ops)(union mm_context *,
 195                                                  struct host_vm_op *, int, int,
 196                                                  void **))
 197 {
 198         pud_t *pud;
 199         unsigned long next;
 200         int ret = 0;
 201
 202         pud = pud_offset(pgd, addr);
 203         do {
 204                 next = pud_addr_end(addr, end);
 205                 if(!pud_present(*pud)){
 206                         if(force || pud_newpage(*pud)){
 207                                 ret = add_munmap(addr, next - addr, ops,
 208                                                  op_index, last_op, mmu,
 209                                                  flush, do_ops);
 210                                 pud_mkuptodate(*pud);
 211                         }
 212                 }
 213                 else ret = update_pmd_range(pud, addr, next, ops, last_op,
 214                                             op_index, force, mmu, flush,
 215                                             do_ops);
 216         } while (pud++, addr = next, ((addr != end) && !ret));
 217         return ret;
 218 }
 219
 220 void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
 221                       unsigned long end_addr, int force,
 222                       int (*do_ops)(union mm_context *, struct host_vm_op *,
 223                                     int, int, void **))
 224 {
 225         pgd_t *pgd;
 226         union mm_context *mmu = &mm->context;
 227         struct host_vm_op ops[1];
 228         unsigned long addr = start_addr, next;
 229         int ret = 0, last_op = ARRAY_SIZE(ops) - 1, op_index = -1;
 230         void *flush = NULL;
 231
 232         ops[0].type = NONE;
 233         pgd = pgd_offset(mm, addr);
 234         do {
 235                 next = pgd_addr_end(addr, end_addr);
 236                 if(!pgd_present(*pgd)){
 237                         if (force || pgd_newpage(*pgd)){
 238                                 ret = add_munmap(addr, next - addr, ops,
 239                                                  &op_index, last_op, mmu,
 240                                                  &flush, do_ops);
 241                                 pgd_mkuptodate(*pgd);
 242                         }
 243                 }
 244                 else ret = update_pud_range(pgd, addr, next, ops, last_op,
 245                                             &op_index, force, mmu, &flush,
 246                                             do_ops);
 247         } while (pgd++, addr = next, ((addr != end_addr) && !ret));
 248
 249         if(!ret)
 250                 ret = (*do_ops)(mmu, ops, op_index, 1, &flush);
 251
 252         /* This is not an else because ret is modified above */
 253         if(ret) {
 254                 printk("fix_range_common: failed, killing current process\n");
 255                 force_sig(SIGKILL, current);
 256         }
 257 }
 258
 259 int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
 260 {
 261         struct mm_struct *mm;
 262         pgd_t *pgd;
 263         pud_t *pud;
 264         pmd_t *pmd;
 265         pte_t *pte;
 266         unsigned long addr, last;
 267         int updated = 0, err;
 268
 269         mm = &init_mm;
 270         for(addr = start; addr < end;){
 271                 pgd = pgd_offset(mm, addr);
 272                 if(!pgd_present(*pgd)){
 273                         last = ADD_ROUND(addr, PGDIR_SIZE);
 274                         if(last > end)
 275                                 last = end;
 276                         if(pgd_newpage(*pgd)){
 277                                 updated = 1;
 278                                 err = os_unmap_memory((void *) addr,
 279                                                       last - addr);
 280                                 if(err < 0)
 281                                         panic("munmap failed, errno = %d\n",
 282                                               -err);
 283                         }
 284                         addr = last;
 285                         continue;
 286                 }
 287
 288                 pud = pud_offset(pgd, addr);
 289                 if(!pud_present(*pud)){
 290                         last = ADD_ROUND(addr, PUD_SIZE);
 291                         if(last > end)
 292                                 last = end;
 293                         if(pud_newpage(*pud)){
 294                                 updated = 1;
 295                                 err = os_unmap_memory((void *) addr,
 296                                                       last - addr);
 297                                 if(err < 0)
 298                                         panic("munmap failed, errno = %d\n",
 299                                               -err);
 300                         }
 301                         addr = last;
 302                         continue;
 303                 }
 304
 305                 pmd = pmd_offset(pud, addr);
 306                 if(!pmd_present(*pmd)){
 307                         last = ADD_ROUND(addr, PMD_SIZE);
 308                         if(last > end)
 309                                 last = end;
 310                         if(pmd_newpage(*pmd)){
 311                                 updated = 1;
 312                                 err = os_unmap_memory((void *) addr,
 313                                                       last - addr);
 314                                 if(err < 0)
 315                                         panic("munmap failed, errno = %d\n",
 316                                               -err);
 317                         }
 318                         addr = last;
 319                         continue;
 320                 }
 321
 322                 pte = pte_offset_kernel(pmd, addr);
 323                 if(!pte_present(*pte) || pte_newpage(*pte)){
 324                         updated = 1;
 325                         err = os_unmap_memory((void *) addr,
 326                                               PAGE_SIZE);
 327                         if(err < 0)
 328                                 panic("munmap failed, errno = %d\n",
 329                                       -err);
 330                         if(pte_present(*pte))
 331                                 map_memory(addr,
 332                                            pte_val(*pte) & PAGE_MASK,
 333                                            PAGE_SIZE, 1, 1, 1);
 334                 }
 335                 else if(pte_newprot(*pte)){
 336                         updated = 1;
 337                         os_protect_memory((void *) addr, PAGE_SIZE, 1, 1, 1);
 338                 }
 339                 addr += PAGE_SIZE;
 340         }
 341         return(updated);
 342 }
 343
 344 void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
 345 {
 346         pgd_t *pgd;
 347         pud_t *pud;
 348         pmd_t *pmd;
 349         pte_t *pte;
 350         struct mm_struct *mm = vma->vm_mm;
 351         void *flush = NULL;
 352         int r, w, x, prot, err = 0;
 353         struct mm_id *mm_id;
 354
 355         address &= PAGE_MASK;
 356         pgd = pgd_offset(mm, address);
 357         if(!pgd_present(*pgd))
 358                 goto kill;
 359
 360         pud = pud_offset(pgd, address);
 361         if(!pud_present(*pud))
 362                 goto kill;
 363
 364         pmd = pmd_offset(pud, address);
 365         if(!pmd_present(*pmd))
 366                 goto kill;
 367
 368         pte = pte_offset_kernel(pmd, address);
 369
 370         r = pte_read(*pte);
 371         w = pte_write(*pte);
 372         x = pte_exec(*pte);
 373         if (!pte_young(*pte)) {
 374                 r = 0;
 375                 w = 0;
 376         } else if (!pte_dirty(*pte)) {
 377                 w = 0;
 378         }
 379
 380         mm_id = &mm->context.skas.id;
 381         prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
 382                 (x ? UM_PROT_EXEC : 0));
 383         if(pte_newpage(*pte)){
 384                 if(pte_present(*pte)){
 385                         unsigned long long offset;
 386                         int fd;
 387
 388                         fd = phys_mapping(pte_val(*pte) & PAGE_MASK, &offset);
 389                         err = map(mm_id, address, PAGE_SIZE, prot, fd, offset,
 390                                   1, &flush);
 391                 }
 392                 else err = unmap(mm_id, address, PAGE_SIZE, 1, &flush);
 393         }
 394         else if(pte_newprot(*pte))
 395                 err = protect(mm_id, address, PAGE_SIZE, prot, 1, &flush);
 396
 397         if(err)
 398                 goto kill;
 399
 400         *pte = pte_mkuptodate(*pte);
 401
 402         return;
 403
 404 kill:
 405         printk("Failed to flush page for address 0x%lx\n", address);
 406         force_sig(SIGKILL, current);
 407 }
 408
 409 pgd_t *pgd_offset_proc(struct mm_struct *mm, unsigned long address)
 410 {
 411         return(pgd_offset(mm, address));
 412 }
 413
 414 pud_t *pud_offset_proc(pgd_t *pgd, unsigned long address)
 415 {
 416         return(pud_offset(pgd, address));
 417 }
 418
 419 pmd_t *pmd_offset_proc(pud_t *pud, unsigned long address)
 420 {
 421         return(pmd_offset(pud, address));
 422 }
 423
 424 pte_t *pte_offset_proc(pmd_t *pmd, unsigned long address)
 425 {
 426         return(pte_offset_kernel(pmd, address));
 427 }
 428
 429 pte_t *addr_pte(struct task_struct *task, unsigned long addr)
 430 {
 431         pgd_t *pgd = pgd_offset(task->mm, addr);
 432         pud_t *pud = pud_offset(pgd, addr);
 433         pmd_t *pmd = pmd_offset(pud, addr);
 434
 435         return(pte_offset_map(pmd, addr));
 436 }
 437
 438 void flush_tlb_all(void)
 439 {
 440         flush_tlb_mm(current->mm);
 441 }
 442
 443 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 444 {
 445         flush_tlb_kernel_range_common(start, end);
 446 }
 447
 448 void flush_tlb_kernel_vm(void)
 449 {
 450         flush_tlb_kernel_range_common(start_vm, end_vm);
 451 }
 452
 453 void __flush_tlb_one(unsigned long addr)
 454 {
 455         flush_tlb_kernel_range_common(addr, addr + PAGE_SIZE);
 456 }
 457
 458 static int do_ops(union mm_context *mmu, struct host_vm_op *ops, int last,
 459                   int finished, void **flush)
 460 {
 461         struct host_vm_op *op;
 462         int i, ret = 0;
 463
 464         for(i = 0; i <= last && !ret; i++){
 465                 op = &ops[i];
 466                 switch(op->type){
 467                 case MMAP:
 468                         ret = map(&mmu->skas.id, op->u.mmap.addr,
 469                                   op->u.mmap.len, op->u.mmap.prot,
 470                                   op->u.mmap.fd, op->u.mmap.offset, finished,
 471                                   flush);
 472                         break;
 473                 case MUNMAP:
 474                         ret = unmap(&mmu->skas.id, op->u.munmap.addr,
 475                                     op->u.munmap.len, finished, flush);
 476                         break;
 477                 case MPROTECT:
 478                         ret = protect(&mmu->skas.id, op->u.mprotect.addr,
 479                                       op->u.mprotect.len, op->u.mprotect.prot,
 480                                       finished, flush);
 481                         break;
 482                 default:
 483                         printk("Unknown op type %d in do_ops\n", op->type);
 484                         break;
 485                 }
 486         }
 487
 488         return ret;
 489 }
 490
 491 static void fix_range(struct mm_struct *mm, unsigned long start_addr,
 492                       unsigned long end_addr, int force)
 493 {
 494         if(!proc_mm && (end_addr > CONFIG_STUB_START))
 495                 end_addr = CONFIG_STUB_START;
 496
 497         fix_range_common(mm, start_addr, end_addr, force, do_ops);
 498 }
 499
 500 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 501                      unsigned long end)
 502 {
 503         if(vma->vm_mm == NULL)
 504                 flush_tlb_kernel_range_common(start, end);
 505         else fix_range(vma->vm_mm, start, end, 0);
 506 }
 507
 508 void flush_tlb_mm(struct mm_struct *mm)
 509 {
 510         unsigned long end;
 511
 512         /* Don't bother flushing if this address space is about to be
 513          * destroyed.
 514          */
 515         if(atomic_read(&mm->mm_users) == 0)
 516                 return;
 517
 518         end = proc_mm ? task_size : CONFIG_STUB_START;
 519         fix_range(mm, 0, end, 0);
 520 }
 521
 522 void force_flush_all(void)
 523 {
 524         struct mm_struct *mm = current->mm;
 525         struct vm_area_struct *vma = mm->mmap;
 526
 527         while(vma != NULL) {
 528                 fix_range(mm, vma->vm_start, vma->vm_end, 1);
 529                 vma = vma->vm_next;
 530         }
 531 }