apps/utils/pice/module/pgflt.c

   1 /*++
   2
   3 Copyright (c) 1998-2001 Klaus P. Gerlicher
   4
   5 Module Name:
   6
   7     pgflt.c
   8
   9 Abstract:
  10
  11     page fault handling on x86
  12
  13 Environment:
  14
  15     Kernel mode only
  16
  17 Author:
  18
  19     Klaus P. Gerlicher
  20
  21 Revision History:
  22
  23     25-Nov-1999:        created
  24     15-Nov-2000:    general cleanup of source files
  25
  26 Copyright notice:
  27
  28   This file may be distributed under the terms of the GNU Public License.
  29
  30 --*/
  31
  32 ////////////////////////////////////////////////////
  33 // INCLUDES
  34 ////
  35 #include "remods.h"
  36
  37 #include "precomp.h"
  38
  39 ////////////////////////////////////////////////////
  40 // GLOBALS
  41 ////
  42
  43 char tempPageFault[1024];
  44 extern void NewInt31Handler(void);
  45
  46 ULONG OldIntEHandler=0;
  47 ULONG error_code;
  48 BOOLEAN bInPageFaultHandler = FALSE;
  49 static ULONG PCR_SEL = PCR_SELECTOR;
  50 static ULONG OLD_PCR;
  51
  52 ////////////////////////////////////////////////////
  53 // FUNCTIONS
  54 ////
  55
  56 //*************************************************************************
  57 // HandleInDebuggerFault()
  58 //
  59 //*************************************************************************
  60 ULONG HandleInDebuggerFault(FRAME* ptr,ULONG address)
  61 {
  62         PEPROCESS tsk;
  63
  64     ENTER_FUNC();
  65
  66         DPRINT((0,"HandleInDebuggerFault(): ###### page fault @ %.8X while inside debugger, eip: %x\n",address, ptr->eip));
  67
  68         // fault in this page fault handler
  69         if(bInPageFaultHandler)
  70         {
  71         DPRINT((0,"HandleInDebuggerFault(): ###### page fault @ %.8X while in page fault handler\n",address));
  72
  73         DPRINT((0,"!!! machine is halted !!!\n"));
  74         __asm__ __volatile__ ("hlt");
  75
  76         LEAVE_FUNC();
  77                 return 0;
  78         }
  79
  80         bInPageFaultHandler = TRUE;
  81
  82     // when we come here from DebuggerShell() we live on a different stack
  83     // so the current task is different as well
  84     tsk = IoGetCurrentProcess();
  85
  86     DPRINT((0,"%.8X (%.4X:%.8X %.8X %s %s %s task=%.8X )\n",
  87         address,
  88         ptr->cs,
  89         ptr->eip,
  90         ptr->eflags,
  91         (ptr->error_code&1)?"PLP":"NP",
  92         (ptr->error_code&2)?"WRITE":"READ",
  93         (ptr->error_code&4)?"USER-MODE":"KERNEL-MODE",
  94         (ULONG)tsk));
  95
  96         if(!bInPrintk)
  97     {
  98         DPRINT((0,"HandleInDebuggerFault(): unexpected pagefault in command handler!\n",address));
  99     }
 100         else
 101     {
 102         DPRINT((0,"HandleInDebuggerFault(): unexpected pagefault in command handler while in PrintkCallback()!\n",address));
 103     }
 104
 105     if(tsk)
 106     {
 107             PULONG pPGD;
 108             PULONG pPTE;
 109
 110         pPGD = ADDR_TO_PDE(address);
 111
 112         DPRINT((0,"PGD for %.8X @ %.8X = %.8X\n",address,(ULONG)pPGD,(ULONG)(*pPGD) ));
 113
 114         if(pPGD && (*pPGD)&_PAGE_PRESENT)
 115         {
 116             // not large page
 117             if(!((*pPGD)&_PAGE_4M))
 118             {
 119                 pPTE = ADDR_TO_PTE(address);
 120                 if(pPTE)
 121                 {
 122                     DPRINT((0,"PTE for %.8X @ %.8X = %.8X\n",address,(ULONG)pPTE,(ULONG)(*pPTE) ));
 123                 }
 124             }
 125         }
 126     }
 127
 128     IntelStackWalk(ptr->eip,CurrentEBP,ulRealStackPtr);
 129
 130     DPRINT((0,"!!! machine is halted !!!\n"));
 131     __asm__ __volatile__ ("hlt");
 132
 133     LEAVE_FUNC();
 134
 135         return 2;
 136 }
 137
 138 //*************************************************************************
 139 // HandlePageFault()
 140 //
 141 // returns:
 142 // 0    =       let the system handle it
 143 // 1    =       call DebuggerShell()
 144 // 2    =       FATAL error inside debugger
 145 //*************************************************************************
 146 ULONG HandlePageFault(FRAME* ptr)
 147 {
 148     PVOID address;
 149         PEPROCESS tsk, tsk1;
 150         PMADDRESS_SPACE vma;
 151     PLIST_ENTRY current_entry;
 152         MEMORY_AREA* current;
 153     ULONG value;
 154         PKTHREAD CurrentThread;
 155         PETHREAD CurrentEThread;
 156
 157         // get linear address of page fault
 158         __asm__ __volatile__("movl %%cr2,%0"
 159                                               :"=r" (address));
 160
 161         DPRINT((0,"\nPageFault: bInDebShell: %d, error: %d, addr: %x\n", bInDebuggerShell, ptr->error_code, address));
 162
 163     // there's something terribly wrong if we get a fault in our command handler
 164     if(bInDebuggerShell)
 165     {
 166                 DPRINT((0,"return handleindebuggerfault\n"));
 167                 return HandleInDebuggerFault(ptr,(ULONG)address);
 168     }
 169
 170         ASSERT(IsAddressValid((ULONG)ptr));
 171     // remember error code so we can push it back on the stack
 172     error_code = ptr->error_code;
 173
 174     //ei Check IRQL here!!!
 175 /*
 176     if(in_interrupt())
 177     {
 178         Print(OUTPUT_WINDOW,"pICE: system is currently processing an interrupt!\n");
 179         return 1;
 180     }
 181 */
 182         // current process
 183     tsk = IoGetCurrentProcess();
 184         DPRINT((0,"tsk: %x\t", tsk));
 185         if( !tsk || !(IsAddressValid((ULONG)tsk))){
 186                 DPRINT((0,"tsk address not valid: tsk: %x\n", tsk));
 187                 return 0;
 188         }
 189
 190         // lookup VMA for this address
 191         if( (ULONG)address > KERNEL_BASE )
 192           vma = my_init_mm;                // use kernel mem area for kernel addresses
 193         else vma = &(tsk->AddressSpace);   // otherwise, use user memory area
 194
 195         if( !vma ){
 196                 DPRINT((0,"vma not valid: vma: %x\n", vma));
 197                 return 0;
 198         }
 199
 200         current_entry = vma->MAreaListHead.Flink;
 201         ASSERT(current_entry);
 202         DPRINT((0,"vma: %x, current_entry: %x, kernel arena: %x\n", vma, current_entry, my_init_mm));
 203         while(current_entry != &vma->MAreaListHead)
 204         {
 205                 ASSERT(current_entry);
 206                 ASSERT(IsAddressValid((ULONG)current_entry));
 207                 current = CONTAINING_RECORD(current_entry,
 208                                                 MEMORY_AREA,
 209                                                 Entry);
 210
 211
 212                 if( (address >= current->BaseAddress) && (address <= current->BaseAddress + current->Length ))
 213                 {
 214                         DPRINT((0,"address: %x    %x - %x Attrib: %x, Type: %x\n", address, current->BaseAddress, current->BaseAddress + current->Length, current->Attributes, current->Type));
 215                         //page not present
 216                         if( !(error_code & 1) ){
 217                                 //check it is in pageable area
 218                                 if( current->Type == MEMORY_AREA_SECTION_VIEW ||
 219                                         current->Type == MEMORY_AREA_VIRTUAL_MEMORY ||
 220                                         current->Type == MEMORY_AREA_PAGED_POOL ||
 221                                         current->Type == MEMORY_AREA_SHARED_DATA
 222                                                 ){
 223                         //ei too much output Print(OUTPUT_WINDOW,"pICE: VMA Pageable Section.\n");
 224                                         //ei DPRINT((0,"return 0 1\n"));
 225                                         return 0; //let the system handle this
 226                                 }
 227                                 Print(OUTPUT_WINDOW,"pICE: VMA Page not present in non-pageable Section!\n");
 228                                 //ei DPRINT((0,"Type: currenttype: %x return 1 2\n", current->Type));
 229                                 return 0;
 230                         }
 231                         else{ //access violation
 232
 233                                 if( error_code & 4 )
 234                                 {   //user mode
 235                                         if( (ULONG)address >= KERNEL_BASE )
 236                                         {
 237                                                 Print(OUTPUT_WINDOW,"pICE: User mode program trying to access kernel memory!\n");
 238                                                 //DPRINT((0,"return 0 3\n"));
 239                                                 return 1;
 240                                         }
 241                                         //DPRINT((0,"return 0 4\n"));
 242                                         return 0;
 243                                 }
 244                                 /*
 245                                 if(error_code & 2)
 246                         {
 247                                         //on write
 248                             if(!(current->Attributes & PAGE_READONLY))
 249                             {
 250                                 Print(OUTPUT_WINDOW,"pICE: virtual memory arena is not writeable!\n");
 251                                 return 1;
 252                             }
 253                         }
 254                         // READ ACCESS
 255                         else
 256                         {
 257                             // test EXT bit in error code
 258                                     if (error_code & 1)
 259                             {
 260                                 Print(OUTPUT_WINDOW,"pICE: page-level protection fault!\n");
 261                                 return 1;
 262                             }
 263                             //
 264                                 */
 265                                         /*
 266                                         if (!(current->Attributes & PAGE_EXECUTE_READ))
 267                             {
 268                                 Print(OUTPUT_WINDOW,"pICE: VMA is not readable!\n");
 269                                 return 1;
 270                             }
 271                                         */
 272
 273                         // let the system handle it
 274                                 //DPRINT((0,"return 0 5\n"));
 275                         return 0;
 276                         }
 277                 }
 278                 current_entry = current_entry->Flink;
 279         }
 280
 281     Print(OUTPUT_WINDOW,"pICE: no virtual memory arena at this address!\n");
 282         DPRINT((0,"return 0 6\n"));
 283         return 1;
 284
 285     // let the system handle it
 286 //    return 0;
 287 }
 288
 289 //*************************************************************************
 290 // NewIntEHandler()
 291 //
 292 //*************************************************************************
 293 __asm__ ("\n\t \
 294 NewIntEHandler:\n\t \
 295                 pushfl\n\t \
 296         cli\n\t \
 297         cld\n\t \
 298         pushal\n\t \
 299             pushl %ds\n\t \
 300 \n\t \
 301             // setup default data selectors\n\t \
 302             movw %ss,%ax\n\t \
 303             movw %ax,%ds\n\t \
 304 \n\t \
 305                 /*\n\t \
 306                  * Load the PCR selector.\n\t \
 307                  */\n\t \
 308                 movl    %fs, %eax\n\t \
 309                 movl    %eax, _OLD_PCR\n\t \
 310                 movl    _PCR_SEL, %eax\n\t \
 311                 movl    %eax, %fs\n\t \
 312 \n\t \
 313         // get frame ptr\n\t \
 314         lea 40(%esp),%eax\n\t \
 315         pushl %eax\n\t \
 316         call _HandlePageFault\n\t \
 317         addl $4,%esp\n\t \
 318 \n\t \
 319                 pushl   %eax\n\t \
 320                 movl    _OLD_PCR, %eax\n\t \
 321                 movl    %eax, %fs\n\t \
 322                 popl    %eax\n\t \
 323 \n\t \
 324         cmpl $0,%eax\n\t \
 325         je call_old_inte_handler\n\t \
 326 \n\t \
 327         cmpl $2,%eax\n\t \
 328         je call_handler_unknown_reason\n\t \
 329 \n\t \
 330             popl %ds\n\t \
 331         popal\n\t \
 332                 popfl\n\t \
 333         // remove error code. will be restored later when we call\n\t \
 334         // original handler again.\n\t \
 335         addl $4,%esp\n\t \
 336                 // call debugger loop\n\t \
 337         pushl $" STR(REASON_PAGEFAULT) "\n\t \
 338                 jmp NewInt31Handler\n\t \
 339 \n\t \
 340 call_old_inte_handler:\n\t \
 341             popl %ds\n\t \
 342         popal\n\t \
 343                 popfl\n\t \
 344                 // chain to old handler\n\t \
 345                 .byte 0x2e\n\t \
 346                 jmp *_OldIntEHandler\n\t \
 347 \n\t \
 348 call_handler_unknown_reason:\n\t \
 349             popl %ds\n\t \
 350         popal\n\t \
 351                 popfl\n\t \
 352         // remove error code. will be restored later when we call\n\t \
 353         // original handler again.\n\t \
 354         addl $4,%esp\n\t \
 355                 // call debugger loop\n\t \
 356         pushl $" STR(REASON_INTERNAL_ERROR) "\n\t \
 357                 jmp NewInt31Handler\n\t \
 358         ");
 359
 360
 361 //*************************************************************************
 362 // InstallIntEHook()
 363 //
 364 //*************************************************************************
 365 void InstallIntEHook(void)
 366 {
 367         ULONG LocalIntEHandler;
 368
 369         ENTER_FUNC();
 370
 371         MaskIrqs();
 372         if(!OldIntEHandler)
 373         {
 374                 __asm__ __volatile__("mov $NewIntEHandler,%0"
 375                         :"=r" (LocalIntEHandler)
 376                         :
 377                         :"eax");
 378                 OldIntEHandler=SetGlobalInt(0x0E,(ULONG)LocalIntEHandler);
 379         }
 380         UnmaskIrqs();
 381         DPRINT((0,"OldIntE @ %x\n", OldIntEHandler));
 382     LEAVE_FUNC();
 383 }
 384
 385 //*************************************************************************
 386 // DeInstallIntEHook()
 387 //
 388 //*************************************************************************
 389 void DeInstallIntEHook(void)
 390 {
 391         ENTER_FUNC();
 392
 393         MaskIrqs();
 394         if(OldIntEHandler)
 395         {
 396                 SetGlobalInt(0x0E,(ULONG)OldIntEHandler);
 397         OldIntEHandler=0;
 398         }
 399         UnmaskIrqs();
 400
 401     LEAVE_FUNC();
 402 }