VirtualBox

source: vbox/trunk/src/VBox/VMM/PATM/CSAM.cpp@ 1996

Last change on this file since 1996 was 1996, checked in by vboxsync, 18 years ago

Round address to page boundary.

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1/* $Id: CSAM.cpp 1996 2007-04-09 13:36:57Z vboxsync $ */
2/** @file
3 * CSAM - Guest OS Code Scanning and Analysis Manager
4 */
5
6/*
7 * Copyright (C) 2006 InnoTek Systemberatung GmbH
8 *
9 * This file is part of VirtualBox Open Source Edition (OSE), as
10 * available from http://www.virtualbox.org. This file is free software;
11 * you can redistribute it and/or modify it under the terms of the GNU
12 * General Public License as published by the Free Software Foundation,
13 * in version 2 as it comes in the "COPYING" file of the VirtualBox OSE
14 * distribution. VirtualBox OSE is distributed in the hope that it will
15 * be useful, but WITHOUT ANY WARRANTY of any kind.
16 *
17 * If you received this file as part of a commercial VirtualBox
18 * distribution, then only the terms of your commercial VirtualBox
19 * license agreement apply instead of the previous paragraph.
20 */
21
22/*******************************************************************************
23* Header Files *
24*******************************************************************************/
25#define LOG_GROUP LOG_GROUP_CSAM
26#include <VBox/cpum.h>
27#include <VBox/stam.h>
28#include <VBox/patm.h>
29#include <VBox/csam.h>
30#include <VBox/cpumdis.h>
31#include <VBox/pgm.h>
32#include <VBox/iom.h>
33#include <VBox/sup.h>
34#include <VBox/mm.h>
35#include <VBox/em.h>
36#include <VBox/rem.h>
37#include <VBox/selm.h>
38#include <VBox/trpm.h>
39#include <VBox/cfgm.h>
40#include <VBox/param.h>
41#include <iprt/avl.h>
42#include <iprt/asm.h>
43#include <iprt/thread.h>
44#include "CSAMInternal.h"
45#include <VBox/vm.h>
46#include <VBox/dbg.h>
47#include <VBox/err.h>
48#include <VBox/ssm.h>
49#include <VBox/log.h>
50#include <iprt/assert.h>
51#include <iprt/string.h>
52#include <VBox/dis.h>
53#include <VBox/disopcode.h>
54#include <stdlib.h>
55#include <stdio.h>
56
57
58/* Enabled by default */
59#define CSAM_ENABLE
60
61/* Enable to monitor code pages for self-modifying code. */
62#define CSAM_MONITOR_CODE_PAGES
63/* Enable to monitor all scanned pages
64#define CSAM_MONITOR_CSAM_CODE_PAGES */
65/* Enable to scan beyond ret instructions.
66#define CSAM_ANALYSE_BEYOND_RET */
67
68/*******************************************************************************
69* Internal Functions *
70*******************************************************************************/
71static DECLCALLBACK(int) csamr3Save(PVM pVM, PSSMHANDLE pSSM);
72static DECLCALLBACK(int) csamr3Load(PVM pVM, PSSMHANDLE pSSM, uint32_t u32Version);
73static DECLCALLBACK(int) CSAMCodePageWriteHandler(PVM pVM, RTGCPTR GCPtr, void *pvPtr, void *pvBuf, size_t cbBuf, PGMACCESSTYPE enmAccessType, void *pvUser);
74static DECLCALLBACK(int) CSAMCodePageInvalidate(PVM pVM, RTGCPTR GCPtr);
75
76bool csamIsCodeScanned(PVM pVM, RTGCPTR pInstr, PCSAMPAGE *pPage);
77int csamR3CheckPageRecord(PVM pVM, RTGCPTR pInstr);
78static PCSAMPAGE csamCreatePageRecord(PVM pVM, RTGCPTR GCPtr, CSAMTAG enmTag, bool fCode32, bool fMonitorInvalidation = false);
79static int csamRemovePageRecord(PVM pVM, RTGCPTR GCPtr);
80static int csamReinit(PVM pVM);
81static void csamMarkCode(PVM pVM, PCSAMPAGE pPage, RTGCPTR pInstr, uint32_t opsize, bool fScanned);
82static int csamAnalyseCodeStream(PVM pVM, GCPTRTYPE(uint8_t *) pInstrGC, GCPTRTYPE(uint8_t *) pCurInstrGC, bool fCode32,
83 PFN_CSAMR3ANALYSE pfnCSAMR3Analyse, void *pUserData, PCSAMP2GLOOKUPREC pCacheRec);
84
85/** @todo Temporary for debugging. */
86static bool fInCSAMCodePageInvalidate = false;
87
88/*******************************************************************************
89* Global Variables *
90*******************************************************************************/
91#ifdef VBOX_WITH_DEBUGGER
92static DECLCALLBACK(int) csamr3CmdOn(PCDBGCCMD pCmd, PDBGCCMDHLP pCmdHlp, PVM pVM, PCDBGCVAR paArgs, unsigned cArgs, PDBGCVAR pResult);
93static DECLCALLBACK(int) csamr3CmdOff(PCDBGCCMD pCmd, PDBGCCMDHLP pCmdHlp, PVM pVM, PCDBGCVAR paArgs, unsigned cArgs, PDBGCVAR pResult);
94
95/** Command descriptors. */
96static const DBGCCMD g_aCmds[] =
97{
98 /* pszCmd, cArgsMin, cArgsMax, paArgDesc, cArgDescs, pResultDesc, fFlags, pfnHandler pszSyntax, ....pszDescription */
99 { "csamon", 0, 0, NULL, 0, NULL, 0, csamr3CmdOn, "", "Enable CSAM code scanning." },
100 { "csamoff", 0, 0, NULL, 0, NULL, 0, csamr3CmdOff, "", "Disable CSAM code scanning." },
101};
102#endif
103
104
105/**
106 * Initializes the CSAM.
107 *
108 * @returns VBox status code.
109 * @param pVM The VM to operate on.
110 */
111CSAMR3DECL(int) CSAMR3Init(PVM pVM)
112{
113 int rc;
114
115 LogFlow(("CSAMR3Init\n"));
116
117 /* Allocate bitmap for the page directory. */
118 rc = MMR3HyperAllocOnceNoRel(pVM, CSAM_PGDIRBMP_CHUNKS*sizeof(RTHCPTR), 0, MM_TAG_CSAM, (void **)&pVM->csam.s.pPDBitmapHC);
119 AssertRCReturn(rc, rc);
120 rc = MMR3HyperAllocOnceNoRel(pVM, CSAM_PGDIRBMP_CHUNKS*sizeof(RTGCPTR), 0, MM_TAG_CSAM, (void **)&pVM->csam.s.pPDGCBitmapHC);
121 AssertRCReturn(rc, rc);
122 pVM->csam.s.pPDBitmapGC = MMHyperHC2GC(pVM, pVM->csam.s.pPDGCBitmapHC);
123 pVM->csam.s.pPDHCBitmapGC = MMHyperHC2GC(pVM, pVM->csam.s.pPDBitmapHC);
124
125 rc = csamReinit(pVM);
126 AssertRCReturn(rc, rc);
127
128 /*
129 * Register save and load state notificators.
130 */
131 rc = SSMR3RegisterInternal(pVM, "CSAM", 0, CSAM_SSM_VERSION, sizeof(pVM->csam.s) + PAGE_SIZE*16,
132 NULL, csamr3Save, NULL,
133 NULL, csamr3Load, NULL);
134 AssertRCReturn(rc, rc);
135
136 STAM_REG(pVM, &pVM->csam.s.StatNrTraps, STAMTYPE_COUNTER, "/CSAM/PageTraps", STAMUNIT_OCCURENCES, "The number of CSAM page traps.");
137 STAM_REG(pVM, &pVM->csam.s.StatDangerousWrite, STAMTYPE_COUNTER, "/CSAM/DangerousWrites", STAMUNIT_OCCURENCES, "The number of dangerous writes that cause a context switch.");
138
139 STAM_REG(pVM, &pVM->csam.s.StatNrPageNPHC, STAMTYPE_COUNTER, "/CSAM/HC/PageNotPresent", STAMUNIT_OCCURENCES, "The number of CSAM pages marked not present.");
140 STAM_REG(pVM, &pVM->csam.s.StatNrPageNPGC, STAMTYPE_COUNTER, "/CSAM/GC/PageNotPresent", STAMUNIT_OCCURENCES, "The number of CSAM pages marked not present.");
141 STAM_REG(pVM, &pVM->csam.s.StatNrPages, STAMTYPE_COUNTER, "/CSAM/PageRec/AddedRW", STAMUNIT_OCCURENCES, "The number of CSAM page records (RW monitoring).");
142 STAM_REG(pVM, &pVM->csam.s.StatNrPagesInv, STAMTYPE_COUNTER, "/CSAM/PageRec/AddedRWI", STAMUNIT_OCCURENCES, "The number of CSAM page records (RW & invalidation monitoring).");
143 STAM_REG(pVM, &pVM->csam.s.StatNrRemovedPages, STAMTYPE_COUNTER, "/CSAM/PageRec/Removed", STAMUNIT_OCCURENCES, "The number of removed CSAM page records.");
144 STAM_REG(pVM, &pVM->csam.s.StatPageRemoveREMFlush,STAMTYPE_COUNTER, "/CSAM/PageRec/Removed/REMFlush", STAMUNIT_OCCURENCES, "The number of removed CSAM page records that caused a REM flush.");
145
146 STAM_REG(pVM, &pVM->csam.s.StatNrPatchPages, STAMTYPE_COUNTER, "/CSAM/PageRec/Patch", STAMUNIT_OCCURENCES, "The number of CSAM patch page records.");
147 STAM_REG(pVM, &pVM->csam.s.StatNrUserPages, STAMTYPE_COUNTER, "/CSAM/PageRec/Ignore/User", STAMUNIT_OCCURENCES, "The number of CSAM user page records (ignored).");
148 STAM_REG(pVM, &pVM->csam.s.StatPagePATM, STAMTYPE_COUNTER, "/CSAM/PageRec/Type/PATM", STAMUNIT_OCCURENCES, "The number of PATM page records.");
149 STAM_REG(pVM, &pVM->csam.s.StatPageCSAM, STAMTYPE_COUNTER, "/CSAM/PageRec/Type/CSAM", STAMUNIT_OCCURENCES, "The number of CSAM page records.");
150 STAM_REG(pVM, &pVM->csam.s.StatPageREM, STAMTYPE_COUNTER, "/CSAM/PageRec/Type/REM", STAMUNIT_OCCURENCES, "The number of REM page records.");
151 STAM_REG(pVM, &pVM->csam.s.StatPageMonitor, STAMTYPE_COUNTER, "/CSAM/PageRec/Monitored", STAMUNIT_OCCURENCES, "The number of monitored pages.");
152
153 STAM_REG(pVM, &pVM->csam.s.StatCodePageModified, STAMTYPE_COUNTER, "/CSAM/Monitor/DirtyPage", STAMUNIT_OCCURENCES, "The number of code page modifications.");
154
155 STAM_REG(pVM, &pVM->csam.s.StatNrFlushes, STAMTYPE_COUNTER, "/CSAM/PageFlushes", STAMUNIT_OCCURENCES, "The number of CSAM page flushes.");
156 STAM_REG(pVM, &pVM->csam.s.StatNrFlushesSkipped, STAMTYPE_COUNTER, "/CSAM/PageFlushesSkipped", STAMUNIT_OCCURENCES, "The number of CSAM page flushes that were skipped.");
157 STAM_REG(pVM, &pVM->csam.s.StatNrKnownPagesHC, STAMTYPE_COUNTER, "/CSAM/HC/KnownPageRecords", STAMUNIT_OCCURENCES, "The number of known CSAM page records.");
158 STAM_REG(pVM, &pVM->csam.s.StatNrKnownPagesGC, STAMTYPE_COUNTER, "/CSAM/GC/KnownPageRecords", STAMUNIT_OCCURENCES, "The number of known CSAM page records.");
159 STAM_REG(pVM, &pVM->csam.s.StatNrInstr, STAMTYPE_COUNTER, "/CSAM/ScannedInstr", STAMUNIT_OCCURENCES, "The number of scanned instructions.");
160 STAM_REG(pVM, &pVM->csam.s.StatNrBytesRead, STAMTYPE_COUNTER, "/CSAM/BytesRead", STAMUNIT_OCCURENCES, "The number of bytes read for scanning.");
161 STAM_REG(pVM, &pVM->csam.s.StatNrOpcodeRead, STAMTYPE_COUNTER, "/CSAM/OpcodeBytesRead", STAMUNIT_OCCURENCES, "The number of opcode bytes read by the recompiler.");
162
163 STAM_REG(pVM, &pVM->csam.s.StatBitmapAlloc, STAMTYPE_COUNTER, "/CSAM/Alloc/PageBitmap", STAMUNIT_OCCURENCES, "The number of page bitmap allocations.");
164
165 STAM_REG(pVM, &pVM->csam.s.StatInstrCacheHit, STAMTYPE_COUNTER, "/CSAM/Cache/Hit", STAMUNIT_OCCURENCES, "The number of dangerous instruction cache hits.");
166 STAM_REG(pVM, &pVM->csam.s.StatInstrCacheMiss, STAMTYPE_COUNTER, "/CSAM/Cache/Miss", STAMUNIT_OCCURENCES, "The number of dangerous instruction cache misses.");
167
168 STAM_REG(pVM, &pVM->csam.s.StatScanNextFunction, STAMTYPE_COUNTER, "/CSAM/Function/Scan/Success", STAMUNIT_OCCURENCES, "The number of found functions beyond the ret border.");
169 STAM_REG(pVM, &pVM->csam.s.StatScanNextFunctionFailed, STAMTYPE_COUNTER, "/CSAM/Function/Scan/Failed", STAMUNIT_OCCURENCES, "The number of refused functions beyond the ret border.");
170
171 STAM_REG(pVM, &pVM->csam.s.StatTime, STAMTYPE_PROFILE, "/PROF/CSAM/Scan", STAMUNIT_TICKS_PER_CALL, "Scanning overhead.");
172 STAM_REG(pVM, &pVM->csam.s.StatTimeCheckAddr, STAMTYPE_PROFILE, "/PROF/CSAM/CheckAddr", STAMUNIT_TICKS_PER_CALL, "Address check overhead.");
173 STAM_REG(pVM, &pVM->csam.s.StatTimeAddrConv, STAMTYPE_PROFILE, "/PROF/CSAM/AddrConv", STAMUNIT_TICKS_PER_CALL, "Address conversion overhead.");
174 STAM_REG(pVM, &pVM->csam.s.StatTimeFlushPage, STAMTYPE_PROFILE, "/PROF/CSAM/FlushPage", STAMUNIT_TICKS_PER_CALL, "Page flushing overhead.");
175 STAM_REG(pVM, &pVM->csam.s.StatTimeDisasm, STAMTYPE_PROFILE, "/PROF/CSAM/Disasm", STAMUNIT_TICKS_PER_CALL, "Disassembly overhead.");
176 STAM_REG(pVM, &pVM->csam.s.StatFlushDirtyPages, STAMTYPE_PROFILE, "/PROF/CSAM/FlushDirtyPage", STAMUNIT_TICKS_PER_CALL, "Dirty page flushing overhead.");
177 STAM_REG(pVM, &pVM->csam.s.StatCheckGates, STAMTYPE_PROFILE, "/PROF/CSAM/CheckGates", STAMUNIT_TICKS_PER_CALL, "CSAMR3CheckGates overhead.");
178
179 /*
180 * Check CFGM option and enable/disable CSAM.
181 */
182 bool fEnabled;
183 rc = CFGMR3QueryBool(CFGMR3GetRoot(pVM), "CSAMEnabled", &fEnabled);
184 if (VBOX_FAILURE(rc))
185#ifdef CSAM_ENABLE
186 fEnabled = true;
187#else
188 fEnabled = false;
189#endif
190 if (fEnabled)
191 CSAMEnableScanning(pVM);
192
193#ifdef VBOX_WITH_DEBUGGER
194 /*
195 * Debugger commands.
196 */
197 static bool fRegisteredCmds = false;
198 if (!fRegisteredCmds)
199 {
200 int rc = DBGCRegisterCommands(&g_aCmds[0], ELEMENTS(g_aCmds));
201 if (VBOX_SUCCESS(rc))
202 fRegisteredCmds = true;
203 }
204#endif
205
206 return VINF_SUCCESS;
207}
208
209/**
210 * (Re)initializes CSAM
211 *
212 * @param pVM The VM.
213 */
214static int csamReinit(PVM pVM)
215{
216 /*
217 * Assert alignment and sizes.
218 */
219 AssertRelease(!(RT_OFFSETOF(VM, csam.s) & 31));
220 AssertRelease(sizeof(pVM->csam.s) <= sizeof(pVM->csam.padding));
221
222 /*
223 * Setup any fixed pointers and offsets.
224 */
225 pVM->csam.s.offVM = RT_OFFSETOF(VM, patm);
226
227 pVM->csam.s.fGatesChecked = false;
228 pVM->csam.s.fScanningStarted = false;
229
230 VM_FF_CLEAR(pVM, VM_FF_CSAM_PENDING_ACTION);
231 pVM->csam.s.cDirtyPages = 0;
232 /* not necessary */
233 memset(pVM->csam.s.pvDirtyBasePage, 0, sizeof(pVM->csam.s.pvDirtyBasePage));
234 memset(pVM->csam.s.pvDirtyFaultPage, 0, sizeof(pVM->csam.s.pvDirtyFaultPage));
235
236 memset(&pVM->csam.s.aDangerousInstr, 0, sizeof(pVM->csam.s.aDangerousInstr));
237 pVM->csam.s.cDangerousInstr = 0;
238 pVM->csam.s.iDangerousInstr = 0;
239
240 /** @note never mess with the pgdir bitmap here! */
241 return VINF_SUCCESS;
242}
243
244/**
245 * Applies relocations to data and code managed by this
246 * component. This function will be called at init and
247 * whenever the VMM need to relocate itself inside the GC.
248 *
249 * The csam will update the addresses used by the switcher.
250 *
251 * @param pVM The VM.
252 * @param offDelta Relocation delta.
253 */
254CSAMR3DECL(void) CSAMR3Relocate(PVM pVM, RTGCINTPTR offDelta)
255{
256 if (offDelta)
257 {
258 /* Adjust pgdir and page bitmap pointers. */
259 pVM->csam.s.pPDBitmapGC = MMHyperHC2GC(pVM, pVM->csam.s.pPDGCBitmapHC);
260 pVM->csam.s.pPDHCBitmapGC = MMHyperHC2GC(pVM, pVM->csam.s.pPDBitmapHC);
261
262 for(int i=0;i<CSAM_PGDIRBMP_CHUNKS;i++)
263 {
264 if (pVM->csam.s.pPDGCBitmapHC[i])
265 {
266 pVM->csam.s.pPDGCBitmapHC[i] += offDelta;
267 }
268 }
269 }
270 return;
271}
272
273/**
274 * Terminates the csam.
275 *
276 * Termination means cleaning up and freeing all resources,
277 * the VM it self is at this point powered off or suspended.
278 *
279 * @returns VBox status code.
280 * @param pVM The VM to operate on.
281 */
282CSAMR3DECL(int) CSAMR3Term(PVM pVM)
283{
284 int rc;
285
286 rc = CSAMR3Reset(pVM);
287 AssertRC(rc);
288
289 /* @todo triggers assertion in MMHyperFree */
290#if 0
291 for(int i=0;i<CSAM_PAGEBMP_CHUNKS;i++)
292 {
293 if (pVM->csam.s.pPDBitmapHC[i])
294 MMHyperFree(pVM, pVM->csam.s.pPDBitmapHC[i]);
295 }
296#endif
297
298 return VINF_SUCCESS;
299}
300
301/**
302 * CSAM reset callback.
303 *
304 * @returns VBox status code.
305 * @param pVM The VM which is reset.
306 */
307CSAMR3DECL(int) CSAMR3Reset(PVM pVM)
308{
309 /* Clear page bitmaps. */
310 for(int i=0;i<CSAM_PGDIRBMP_CHUNKS;i++)
311 {
312 if (pVM->csam.s.pPDBitmapHC[i])
313 {
314 Assert((CSAM_PAGE_BITMAP_SIZE& 3) == 0);
315 ASMMemZero32(pVM->csam.s.pPDBitmapHC[i], CSAM_PAGE_BITMAP_SIZE);
316 }
317 }
318
319 /* Remove all CSAM page records. */
320 while(true)
321 {
322 PCSAMPAGEREC pPageRec = (PCSAMPAGEREC)RTAvlPVGetBestFit(&pVM->csam.s.pPageTree, 0, true);
323 if (pPageRec)
324 {
325 csamRemovePageRecord(pVM, pPageRec->page.pPageGC);
326 }
327 else
328 break;
329 }
330 Assert(!pVM->csam.s.pPageTree);
331
332 csamReinit(pVM);
333
334 return VINF_SUCCESS;
335}
336
337#define CSAM_SUBTRACT_PTR(a, b) *(uintptr_t *)&(a) = (uintptr_t)(a) - (uintptr_t)(b)
338#define CSAM_ADD_PTR(a, b) *(uintptr_t *)&(a) = (uintptr_t)(a) + (uintptr_t)(b)
339
340
341/**
342 * Callback function for RTAvlPVDoWithAll
343 *
344 * Counts the number of records in the tree
345 *
346 * @returns VBox status code.
347 * @param pNode Current node
348 * @param pcPatches Pointer to patch counter
349 */
350static DECLCALLBACK(int) CountRecord(PAVLPVNODECORE pNode, void *pcPatches)
351{
352 *(uint32_t *)pcPatches = *(uint32_t *)pcPatches + 1;
353 return VINF_SUCCESS;
354}
355
356/**
357 * Callback function for RTAvlPVDoWithAll
358 *
359 * Saves the state of the page record
360 *
361 * @returns VBox status code.
362 * @param pNode Current node
363 * @param pVM1 VM Handle
364 */
365static DECLCALLBACK(int) SavePageState(PAVLPVNODECORE pNode, void *pVM1)
366{
367 PVM pVM = (PVM)pVM1;
368 PCSAMPAGEREC pPage = (PCSAMPAGEREC)pNode;
369 CSAMPAGEREC page = *pPage;
370 PSSMHANDLE pSSM = pVM->csam.s.savedstate.pSSM;
371 int rc;
372
373 /* Save the page record itself */
374 rc = SSMR3PutMem(pSSM, &page, sizeof(page));
375 AssertRCReturn(rc, rc);
376
377 if (page.page.pBitmap)
378 {
379 rc = SSMR3PutMem(pSSM, page.page.pBitmap, CSAM_PAGE_BITMAP_SIZE);
380 AssertRCReturn(rc, rc);
381 }
382
383 return VINF_SUCCESS;
384}
385
386/**
387 * Execute state save operation.
388 *
389 * @returns VBox status code.
390 * @param pVM VM Handle.
391 * @param pSSM SSM operation handle.
392 */
393static DECLCALLBACK(int) csamr3Save(PVM pVM, PSSMHANDLE pSSM)
394{
395 CSAM csamInfo = pVM->csam.s;
396 int rc;
397
398 /*
399 * Count the number of page records in the tree (feeling lazy)
400 */
401 csamInfo.savedstate.cPageRecords = 0;
402 RTAvlPVDoWithAll(&pVM->csam.s.pPageTree, true, CountRecord, &csamInfo.savedstate.cPageRecords);
403
404 /*
405 * Save CSAM structure
406 */
407 pVM->csam.s.savedstate.pSSM = pSSM;
408 rc = SSMR3PutMem(pSSM, &csamInfo, sizeof(csamInfo));
409 AssertRCReturn(rc, rc);
410
411 /* Save pgdir bitmap */
412 rc = SSMR3PutMem(pSSM, csamInfo.pPDBitmapHC, CSAM_PGDIRBMP_CHUNKS*sizeof(RTHCPTR));
413 AssertRCReturn(rc, rc);
414
415 for (unsigned i=0;i<CSAM_PGDIRBMP_CHUNKS;i++)
416 {
417 if(csamInfo.pPDBitmapHC[i])
418 {
419 /* Save the page bitmap. */
420 rc = SSMR3PutMem(pSSM, csamInfo.pPDBitmapHC[i], CSAM_PAGE_BITMAP_SIZE);
421 AssertRCReturn(rc, rc);
422 }
423 }
424
425 /*
426 * Save page records
427 */
428 rc = RTAvlPVDoWithAll(&pVM->csam.s.pPageTree, true, SavePageState, pVM);
429 AssertRCReturn(rc, rc);
430
431 /** @note we don't restore aDangerousInstr; it will be recreated automatically. */
432 return VINF_SUCCESS;
433}
434
435/**
436 * Execute state load operation.
437 *
438 * @returns VBox status code.
439 * @param pVM VM Handle.
440 * @param pSSM SSM operation handle.
441 * @param u32Version Data layout version.
442 */
443static DECLCALLBACK(int) csamr3Load(PVM pVM, PSSMHANDLE pSSM, uint32_t u32Version)
444{
445 int rc;
446 CSAM csamInfo;
447
448 if (u32Version != CSAM_SSM_VERSION)
449 return VERR_SSM_UNSUPPORTED_DATA_UNIT_VERSION;
450
451 pVM->csam.s.savedstate.pSSM = pSSM;
452
453 /*
454 * Restore CSAM structure
455 */
456 rc = SSMR3GetMem(pSSM, &csamInfo, sizeof(csamInfo));
457 AssertRCReturn(rc, rc);
458
459 pVM->csam.s.fGatesChecked = csamInfo.fGatesChecked;
460 pVM->csam.s.fScanningStarted = csamInfo.fScanningStarted;
461
462 /* Restore dirty code page info. */
463 pVM->csam.s.cDirtyPages = csamInfo.cDirtyPages;
464 memcpy(pVM->csam.s.pvDirtyBasePage, csamInfo.pvDirtyBasePage, sizeof(pVM->csam.s.pvDirtyBasePage));
465 memcpy(pVM->csam.s.pvDirtyFaultPage, csamInfo.pvDirtyFaultPage, sizeof(pVM->csam.s.pvDirtyFaultPage));
466
467 /* Restore possible code page */
468 pVM->csam.s.cPossibleCodePages = csamInfo.cPossibleCodePages;
469 memcpy(pVM->csam.s.pvPossibleCodePage, csamInfo.pvPossibleCodePage, sizeof(pVM->csam.s.pvPossibleCodePage));
470
471 /* Restore pgdir bitmap (we'll change the pointers next). */
472 rc = SSMR3GetMem(pSSM, pVM->csam.s.pPDBitmapHC, CSAM_PGDIRBMP_CHUNKS*sizeof(RTHCPTR));
473 AssertRCReturn(rc, rc);
474
475 /*
476 * Restore page bitmaps
477 */
478 for (unsigned i=0;i<CSAM_PGDIRBMP_CHUNKS;i++)
479 {
480 if(pVM->csam.s.pPDBitmapHC[i])
481 {
482 rc = MMHyperAlloc(pVM, CSAM_PAGE_BITMAP_SIZE, 0, MM_TAG_CSAM, (void **)&pVM->csam.s.pPDBitmapHC[i]);
483 if (VBOX_FAILURE(rc))
484 {
485 Log(("MMR3HyperAlloc failed with %d\n", rc));
486 return rc;
487 }
488 /* Convert to GC pointer. */
489 pVM->csam.s.pPDGCBitmapHC[i] = MMHyperHC2GC(pVM, pVM->csam.s.pPDBitmapHC[i]);
490 Assert(pVM->csam.s.pPDGCBitmapHC[i]);
491
492 /* Restore the bitmap. */
493 rc = SSMR3GetMem(pSSM, pVM->csam.s.pPDBitmapHC[i], CSAM_PAGE_BITMAP_SIZE);
494 AssertRCReturn(rc, rc);
495 }
496 else
497 {
498 Assert(!pVM->csam.s.pPDGCBitmapHC[i]);
499 pVM->csam.s.pPDGCBitmapHC[i] = 0;
500 }
501 }
502
503 /*
504 * Restore page records
505 */
506 for (uint32_t i=0;i<csamInfo.savedstate.cPageRecords + csamInfo.savedstate.cPatchPageRecords;i++)
507 {
508 CSAMPAGEREC page;
509 PCSAMPAGE pPage;
510
511 rc = SSMR3GetMem(pSSM, &page, sizeof(page));
512 AssertRCReturn(rc, rc);
513
514 /*
515 * Recreate the page record
516 */
517 pPage = csamCreatePageRecord(pVM, page.page.pPageGC, page.page.enmTag, page.page.fCode32, page.page.fMonitorInvalidation);
518 AssertReturn(pPage, VERR_NO_MEMORY);
519
520 pPage->GCPhys = page.page.GCPhys;
521 pPage->fFlags = page.page.fFlags;
522 pPage->u64Hash = page.page.u64Hash;
523
524 if (page.page.pBitmap)
525 {
526 rc = SSMR3GetMem(pSSM, pPage->pBitmap, CSAM_PAGE_BITMAP_SIZE);
527 AssertRCReturn(rc, rc);
528 }
529 else
530 {
531 MMR3HeapFree(pPage->pBitmap);
532 pPage->pBitmap = 0;
533 }
534 }
535
536 /** @note we don't restore aDangerousInstr; it will be recreated automatically. */
537 memset(&pVM->csam.s.aDangerousInstr, 0, sizeof(pVM->csam.s.aDangerousInstr));
538 pVM->csam.s.cDangerousInstr = 0;
539 pVM->csam.s.iDangerousInstr = 0;
540 return VINF_SUCCESS;
541}
542
543/**
544 * Convert guest context address to host context pointer
545 *
546 * @returns VBox status code.
547 * @param pVM The VM to operate on.
548 * @param pCacheRec Address conversion cache record
549 * @param pGCPtr Guest context pointer
550 *
551 * @returns Host context pointer or NULL in case of an error
552 *
553 */
554static HCPTRTYPE(void *) CSAMGCVirtToHCVirt(PVM pVM, PCSAMP2GLOOKUPREC pCacheRec, GCPTRTYPE(uint8_t *)pGCPtr)
555{
556 int rc;
557 HCPTRTYPE(void *)pHCPtr;
558
559 STAM_PROFILE_START(&pVM->csam.s.StatTimeAddrConv, a);
560
561 pHCPtr = PATMR3GCPtrToHCPtr(pVM, pGCPtr);
562 if (pHCPtr) return pHCPtr;
563
564 if (pCacheRec->pPageLocStartHC)
565 {
566 uint32_t offset = pGCPtr & PAGE_OFFSET_MASK;
567 if (pCacheRec->pGuestLoc == (pGCPtr & PAGE_BASE_GC_MASK))
568 {
569 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeAddrConv, a);
570 return pCacheRec->pPageLocStartHC + offset;
571 }
572 }
573
574 rc = PGMPhysGCPtr2HCPtr(pVM, pGCPtr, &pHCPtr);
575 if (rc != VINF_SUCCESS)
576 {
577//// AssertMsgRC(rc, ("MMR3PhysGCVirt2HCVirtEx failed for %VGv\n", pGCPtr));
578 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeAddrConv, a);
579 return NULL;
580 }
581////invalid? Assert(sizeof(HCPTRTYPE(uint8_t*)) == sizeof(uint32_t));
582
583 pCacheRec->pPageLocStartHC = (HCPTRTYPE(uint8_t*))((RTHCUINTPTR)pHCPtr & PAGE_BASE_HC_MASK);
584 pCacheRec->pGuestLoc = pGCPtr & PAGE_BASE_GC_MASK;
585 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeAddrConv, a);
586 return pHCPtr;
587}
588
589/**
590 * Read callback for disassembly function; supports reading bytes that cross a page boundary
591 *
592 * @returns VBox status code.
593 * @param pSrc GC source pointer
594 * @param pDest HC destination pointer
595 * @param size Number of bytes to read
596 * @param dwUserdata Callback specific user data (pCpu)
597 *
598 */
599int32_t CSAMR3ReadBytes(RTHCUINTPTR pSrc, uint8_t *pDest, uint32_t size, RTHCUINTPTR dwUserdata)
600{
601 DISCPUSTATE *pCpu = (DISCPUSTATE *)dwUserdata;
602 PVM pVM = (PVM)pCpu->dwUserData[0];
603 RTHCUINTPTR pInstrHC = pCpu->dwUserData[1];
604 RTGCUINTPTR pInstrGC = pCpu->dwUserData[2];
605 int orgsize = size;
606
607 Assert(sizeof(RTHCUINTPTR) <= sizeof(pCpu->dwUserData[0]));
608 Assert(sizeof(RTGCUINTPTR) <= sizeof(pCpu->dwUserData[0]));
609
610 /* We are not interested in patched instructions, so read the original opcode bytes. */
611 /** @note single instruction patches (int3) are checked in CSAMR3AnalyseCallback */
612 for (int i=0;i<orgsize;i++)
613 {
614 int rc = PATMR3QueryOpcode(pVM, (RTGCPTR)pSrc, pDest);
615 if (VBOX_SUCCESS(rc))
616 {
617 pSrc++;
618 pDest++;
619 size--;
620 }
621 else
622 break;
623 }
624 if (size == 0)
625 return VINF_SUCCESS;
626
627 if (PAGE_ADDRESS(pInstrGC) != PAGE_ADDRESS(pSrc + size - 1) && !PATMIsPatchGCAddr(pVM, pSrc))
628 {
629 return PGMPhysReadGCPtr(pVM, pDest, pSrc, size);
630 }
631 else
632 {
633 Assert(pInstrHC);
634
635 /* pInstrHC is the base address; adjust according to the GC pointer. */
636 pInstrHC = pInstrHC + (pSrc - pInstrGC);
637
638 memcpy(pDest, (void *)pInstrHC, size);
639 }
640
641 return VINF_SUCCESS;
642}
643
644inline bool CSAMR3DISInstr(PVM pVM, DISCPUSTATE *pCpu, RTGCPTR InstrGC, uint8_t *InstrHC, uint32_t *pOpsize, char *pszOutput)
645{
646 (pCpu)->pfnReadBytes = CSAMR3ReadBytes;
647 (pCpu)->dwUserData[0] = (RTHCUINTPTR)pVM;
648 (pCpu)->dwUserData[1] = (RTHCUINTPTR)InstrHC;
649 (pCpu)->dwUserData[2] = (RTHCUINTPTR)InstrGC;
650#ifdef DEBUG
651 return DISInstrEx(pCpu, InstrGC, 0, pOpsize, pszOutput, OPTYPE_ALL);
652#else
653 /* We are interested in everything except harmless stuff */
654 return DISInstrEx(pCpu, InstrGC, 0, pOpsize, pszOutput, ~(OPTYPE_INVALID | OPTYPE_HARMLESS | OPTYPE_RRM_MASK));
655#endif
656}
657
658/**
659 * Analyses the instructions following the cli for compliance with our heuristics for cli
660 *
661 * @returns VBox status code.
662 * @param pVM The VM to operate on.
663 * @param pCpu CPU disassembly state
664 * @param pInstrGC Guest context pointer to privileged instruction
665 * @param pCurInstrGC Guest context pointer to the current instruction
666 * @param pCacheRec GC to HC cache record
667 * @param pUserData User pointer (callback specific)
668 *
669 */
670static int CSAMR3AnalyseCallback(PVM pVM, DISCPUSTATE *pCpu, GCPTRTYPE(uint8_t *) pInstrGC, GCPTRTYPE(uint8_t *) pCurInstrGC,
671 PCSAMP2GLOOKUPREC pCacheRec, void *pUserData)
672{
673 PCSAMPAGE pPage = (PCSAMPAGE)pUserData;
674 int rc;
675
676 switch(pCpu->pCurInstr->opcode)
677 {
678 case OP_INT:
679 Assert(pCpu->param1.flags & USE_IMMEDIATE8);
680 if (pCpu->param1.parval == 3)
681 {
682 //two byte int 3
683 return VINF_SUCCESS;
684 }
685 break;
686
687 case OP_ILLUD2:
688 /* This appears to be some kind of kernel panic in Linux 2.4; no point to continue. */
689 case OP_RETN:
690 case OP_INT3:
691 case OP_INVALID:
692#if 1
693 /* removing breaks win2k guests? */
694 case OP_IRET:
695#endif
696 return VINF_SUCCESS;
697 }
698
699 // Check for exit points
700 switch (pCpu->pCurInstr->opcode)
701 {
702 /* It's not a good idea to patch pushf instructions:
703 * - increases the chance of conflicts (code jumping to the next instruction)
704 * - better to patch the cli
705 * - code that branches before the cli will likely hit an int 3
706 * - in general doesn't offer any benefits as we don't allow nested patch blocks (IF is always 1)
707 */
708 case OP_PUSHF:
709 case OP_POPF:
710 break;
711
712 case OP_CLI:
713 {
714 uint32_t cbInstr = 0;
715 uint32_t opsize = pCpu->opsize;
716
717 PATMR3AddHint(pVM, pCurInstrGC, (pPage->fCode32) ? PATMFL_CODE32 : 0);
718
719 /* Make sure the instructions that follow the cli have not been encountered before. */
720 while (true)
721 {
722 DISCPUSTATE cpu;
723 uint8_t *pCurInstrHC = 0;
724 bool disret;
725
726 if (cbInstr + opsize >= SIZEOF_NEARJUMP32)
727 break;
728
729 if (csamIsCodeScanned(pVM, pCurInstrGC + opsize, &pPage) == true)
730 {
731 /* We've scanned the next instruction(s) already. This means we've followed a branch that ended up there before -> dangerous!! */
732 PATMR3DetectConflict(pVM, pCurInstrGC, pCurInstrGC + opsize);
733 break;
734 }
735 pCurInstrGC += opsize;
736 cbInstr += opsize;
737
738 pCurInstrHC = (uint8_t *)CSAMGCVirtToHCVirt(pVM, pCacheRec, pCurInstrGC);
739 if (pCurInstrHC == NULL)
740 {
741 Log(("CSAMGCVirtToHCVirt failed for %VGv\n", pCurInstrGC));
742 break;
743 }
744 Assert(VALID_PTR(pCurInstrHC));
745
746 cpu.mode = (pPage->fCode32) ? CPUMODE_32BIT : CPUMODE_16BIT;
747 disret = CSAMR3DISInstr(pVM, &cpu, pCurInstrGC, pCurInstrHC, &opsize, NULL);
748 Assert(disret == true);
749 if (disret == false)
750 break;
751 }
752 break;
753 }
754
755 case OP_PUSH:
756 if (pCpu->pCurInstr->param1 != OP_PARM_REG_CS)
757 break;
758
759 /* no break */
760 case OP_STR:
761 case OP_LSL:
762 case OP_LAR:
763 case OP_SGDT:
764 case OP_SLDT:
765 case OP_SIDT:
766 case OP_SMSW:
767 case OP_VERW:
768 case OP_VERR:
769 case OP_CPUID:
770 case OP_IRET:
771#ifdef DEBUG
772 switch(pCpu->pCurInstr->opcode)
773 {
774 case OP_STR:
775 Log(("Privileged instruction at %VGv: str!!\n", pCurInstrGC));
776 break;
777 case OP_LSL:
778 Log(("Privileged instruction at %VGv: lsl!!\n", pCurInstrGC));
779 break;
780 case OP_LAR:
781 Log(("Privileged instruction at %VGv: lar!!\n", pCurInstrGC));
782 break;
783 case OP_SGDT:
784 Log(("Privileged instruction at %VGv: sgdt!!\n", pCurInstrGC));
785 break;
786 case OP_SLDT:
787 Log(("Privileged instruction at %VGv: sldt!!\n", pCurInstrGC));
788 break;
789 case OP_SIDT:
790 Log(("Privileged instruction at %VGv: sidt!!\n", pCurInstrGC));
791 break;
792 case OP_SMSW:
793 Log(("Privileged instruction at %VGv: smsw!!\n", pCurInstrGC));
794 break;
795 case OP_VERW:
796 Log(("Privileged instruction at %VGv: verw!!\n", pCurInstrGC));
797 break;
798 case OP_VERR:
799 Log(("Privileged instruction at %VGv: verr!!\n", pCurInstrGC));
800 break;
801 case OP_CPUID:
802 Log(("Privileged instruction at %VGv: cpuid!!\n", pCurInstrGC));
803 break;
804 case OP_PUSH:
805 Log(("Privileged instruction at %VGv: push cs!!\n", pCurInstrGC));
806 break;
807 case OP_IRET:
808 Log(("Privileged instruction at %VGv: iret!!\n", pCurInstrGC));
809 break;
810 }
811#endif
812
813 if (PATMR3HasBeenPatched(pVM, pCurInstrGC) == false)
814 {
815 rc = PATMR3InstallPatch(pVM, pCurInstrGC, (pPage->fCode32) ? PATMFL_CODE32 : 0);
816 if (VBOX_FAILURE(rc))
817 {
818 Log(("PATMR3InstallPatch failed with %d\n", rc));
819 return VWRN_CONTINUE_ANALYSIS;
820 }
821 }
822 if (pCpu->pCurInstr->opcode == OP_IRET)
823 return VINF_SUCCESS; /* Look no further in this branch. */
824
825 return VWRN_CONTINUE_ANALYSIS;
826
827 case OP_JMP:
828 case OP_CALL:
829 {
830 // return or jump/call through a jump table
831 if (OP_PARM_VTYPE(pCpu->pCurInstr->param1) != OP_PARM_J)
832 {
833#ifdef DEBUG
834 switch(pCpu->pCurInstr->opcode)
835 {
836 case OP_JMP:
837 Log(("Control Flow instruction at %VGv: jmp!!\n", pCurInstrGC));
838 break;
839 case OP_CALL:
840 Log(("Control Flow instruction at %VGv: call!!\n", pCurInstrGC));
841 break;
842 }
843#endif
844 return VWRN_CONTINUE_ANALYSIS;
845 }
846 return VWRN_CONTINUE_ANALYSIS;
847 }
848
849 }
850
851 return VWRN_CONTINUE_ANALYSIS;
852}
853
854#ifdef CSAM_ANALYSE_BEYOND_RET
855/**
856 * Wrapper for csamAnalyseCodeStream for call instructions.
857 *
858 * @returns VBox status code.
859 * @param pVM The VM to operate on.
860 * @param pInstrGC Guest context pointer to privileged instruction
861 * @param pCurInstrGC Guest context pointer to the current instruction
862 * @param fCode32 16 or 32 bits code
863 * @param pfnCSAMR3Analyse Callback for testing the disassembled instruction
864 * @param pUserData User pointer (callback specific)
865 *
866 */
867static int csamAnalyseCallCodeStream(PVM pVM, GCPTRTYPE(uint8_t *) pInstrGC, GCPTRTYPE(uint8_t *) pCurInstrGC, bool fCode32,
868 PFN_CSAMR3ANALYSE pfnCSAMR3Analyse, void *pUserData, PCSAMP2GLOOKUPREC pCacheRec)
869{
870 int rc;
871 CSAMCALLEXITREC CallExitRec;
872 PCSAMCALLEXITREC pOldCallRec;
873 PCSAMPAGE pPage = 0;
874 uint32_t i;
875
876 CallExitRec.cInstrAfterRet = 0;
877
878 pOldCallRec = pCacheRec->pCallExitRec;
879 pCacheRec->pCallExitRec = &CallExitRec;
880
881 rc = csamAnalyseCodeStream(pVM, pInstrGC, pCurInstrGC, fCode32, pfnCSAMR3Analyse, pUserData, pCacheRec);
882
883 for (i=0;i<CallExitRec.cInstrAfterRet;i++)
884 {
885 PCSAMPAGE pPage = 0;
886
887 pCurInstrGC = CallExitRec.pInstrAfterRetGC[i];
888
889 /* Check if we've previously encountered the instruction after the ret. */
890 if (csamIsCodeScanned(pVM, pCurInstrGC, &pPage) == false)
891 {
892 DISCPUSTATE cpu;
893 uint32_t opsize;
894 uint8_t *pCurInstrHC = 0;
895 bool disret;
896#ifdef DEBUG
897 char szOutput[256];
898#endif
899 if (pPage == NULL)
900 {
901 /* New address; let's take a look at it. */
902 pPage = csamCreatePageRecord(pVM, pCurInstrGC, CSAM_TAG_CSAM, fCode32);
903 if (pPage == NULL)
904 {
905 rc = VERR_NO_MEMORY;
906 goto done;
907 }
908 }
909
910 /**
911 * Some generic requirements for recognizing an adjacent function:
912 * - alignment fillers that consist of:
913 * - nop
914 * - lea genregX, [genregX (+ 0)]
915 * - push ebp after the filler (can extend this later); aligned at at least a 4 byte boundary
916 */
917 for (int j=0;j<16;j++)
918 {
919 pCurInstrHC = (uint8_t *)CSAMGCVirtToHCVirt(pVM, pCacheRec, pCurInstrGC);
920 if (pCurInstrHC == NULL)
921 {
922 Log(("CSAMGCVirtToHCVirt failed for %VGv\n", pCurInstrGC));
923 goto done;
924 }
925 Assert(VALID_PTR(pCurInstrHC));
926
927 cpu.mode = (fCode32) ? CPUMODE_32BIT : CPUMODE_16BIT;
928 STAM_PROFILE_START(&pVM->csam.s.StatTimeDisasm, a);
929#ifdef DEBUG
930 disret = CSAMR3DISInstr(pVM, &cpu, pCurInstrGC, pCurInstrHC, &opsize, szOutput);
931 if (disret == true) Log(("CSAM Call Analysis: %s", szOutput));
932#else
933 disret = CSAMR3DISInstr(pVM, &cpu, pCurInstrGC, pCurInstrHC, &opsize, NULL);
934#endif
935 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeDisasm, a);
936 if (disret == false)
937 {
938 Log(("Disassembly failed at %VGv (probably page not present) -> return to caller\n", pCurInstrGC));
939 goto done;
940 }
941
942 STAM_COUNTER_ADD(&pVM->csam.s.StatNrBytesRead, opsize);
943
944 GCPTRTYPE(uint8_t *) addr = 0;
945 PCSAMPAGE pJmpPage = NULL;
946
947 if (PAGE_ADDRESS(pCurInstrGC) != PAGE_ADDRESS(pCurInstrGC + opsize - 1))
948 {
949 if (!PGMGstIsPagePresent(pVM, pCurInstrGC + opsize - 1))
950 {
951 /// @todo fault in the page
952 Log(("Page for current instruction %VGv is not present!!\n", pCurInstrGC));
953 goto done;
954 }
955 //all is fine, let's continue
956 csamR3CheckPageRecord(pVM, pCurInstrGC + opsize - 1);
957 }
958
959 switch (cpu.pCurInstr->opcode)
960 {
961 case OP_NOP:
962 case OP_INT3:
963 break; /* acceptable */
964
965 case OP_LEA:
966 /* Must be similar to:
967 *
968 * lea esi, [esi]
969 * lea esi, [esi+0]
970 * Any register is allowed as long as source and destination are identical.
971 */
972 if ( cpu.param1.flags != USE_REG_GEN32
973 || ( cpu.param2.flags != USE_REG_GEN32
974 && ( !(cpu.param2.flags & USE_REG_GEN32)
975 || !(cpu.param2.flags & (USE_DISPLACEMENT8|USE_DISPLACEMENT16|USE_DISPLACEMENT32))
976 || cpu.param2.parval != 0
977 )
978 )
979 || cpu.param1.base.reg_gen32 != cpu.param2.base.reg_gen32
980 )
981 {
982 STAM_COUNTER_INC(&pVM->csam.s.StatScanNextFunctionFailed);
983 goto next_function;
984 }
985 break;
986
987 case OP_PUSH:
988 {
989 if ( (pCurInstrGC & 0x3) != 0
990 || cpu.param1.flags != USE_REG_GEN32
991 || cpu.param1.base.reg_gen32 != USE_REG_EBP
992 )
993 {
994 STAM_COUNTER_INC(&pVM->csam.s.StatScanNextFunctionFailed);
995 goto next_function;
996 }
997
998 if (csamIsCodeScanned(pVM, pCurInstrGC, &pPage) == false)
999 {
1000 CSAMCALLEXITREC CallExitRec2;
1001 CallExitRec2.cInstrAfterRet = 0;
1002
1003 pCacheRec->pCallExitRec = &CallExitRec2;
1004
1005 /* Analyse the function. */
1006 Log(("Found new function at %VGv\n", pCurInstrGC));
1007 STAM_COUNTER_INC(&pVM->csam.s.StatScanNextFunction);
1008 csamAnalyseCallCodeStream(pVM, pInstrGC, pCurInstrGC, fCode32, pfnCSAMR3Analyse, pUserData, pCacheRec);
1009 }
1010 goto next_function;
1011 }
1012
1013 case OP_SUB:
1014 {
1015 if ( (pCurInstrGC & 0x3) != 0
1016 || cpu.param1.flags != USE_REG_GEN32
1017 || cpu.param1.base.reg_gen32 != USE_REG_ESP
1018 )
1019 {
1020 STAM_COUNTER_INC(&pVM->csam.s.StatScanNextFunctionFailed);
1021 goto next_function;
1022 }
1023
1024 if (csamIsCodeScanned(pVM, pCurInstrGC, &pPage) == false)
1025 {
1026 CSAMCALLEXITREC CallExitRec2;
1027 CallExitRec2.cInstrAfterRet = 0;
1028
1029 pCacheRec->pCallExitRec = &CallExitRec2;
1030
1031 /* Analyse the function. */
1032 Log(("Found new function at %VGv\n", pCurInstrGC));
1033 STAM_COUNTER_INC(&pVM->csam.s.StatScanNextFunction);
1034 csamAnalyseCallCodeStream(pVM, pInstrGC, pCurInstrGC, fCode32, pfnCSAMR3Analyse, pUserData, pCacheRec);
1035 }
1036 goto next_function;
1037 }
1038
1039 default:
1040 STAM_COUNTER_INC(&pVM->csam.s.StatScanNextFunctionFailed);
1041 goto next_function;
1042 }
1043 /* Mark it as scanned. */
1044 csamMarkCode(pVM, pPage, pCurInstrGC, opsize, true);
1045 pCurInstrGC += opsize;
1046 } /* for at most 16 instructions */
1047next_function:
1048 ; /* MSVC complains otherwise */
1049 }
1050 }
1051done:
1052 pCacheRec->pCallExitRec = pOldCallRec;
1053 return rc;
1054}
1055#else
1056#define csamAnalyseCallCodeStream csamAnalyseCodeStream
1057#endif
1058
1059/**
1060 * Disassembles the code stream until the callback function detects a failure or decides everything is acceptable
1061 *
1062 * @returns VBox status code.
1063 * @param pVM The VM to operate on.
1064 * @param pInstrGC Guest context pointer to privileged instruction
1065 * @param pCurInstrGC Guest context pointer to the current instruction
1066 * @param fCode32 16 or 32 bits code
1067 * @param pfnCSAMR3Analyse Callback for testing the disassembled instruction
1068 * @param pUserData User pointer (callback specific)
1069 *
1070 */
1071static int csamAnalyseCodeStream(PVM pVM, GCPTRTYPE(uint8_t *) pInstrGC, GCPTRTYPE(uint8_t *) pCurInstrGC, bool fCode32,
1072 PFN_CSAMR3ANALYSE pfnCSAMR3Analyse, void *pUserData, PCSAMP2GLOOKUPREC pCacheRec)
1073{
1074 DISCPUSTATE cpu;
1075 PCSAMPAGE pPage = (PCSAMPAGE)pUserData;
1076 int rc = VWRN_CONTINUE_ANALYSIS;
1077 uint32_t opsize;
1078 HCPTRTYPE(uint8_t *)pCurInstrHC = 0;
1079 bool disret;
1080
1081#ifdef DEBUG
1082 char szOutput[256];
1083#endif
1084
1085 LogFlow(("csamAnalyseCodeStream: code at %VGv depth=%d\n", pCurInstrGC, pCacheRec->depth));
1086
1087 pVM->csam.s.fScanningStarted = true;
1088
1089 pCacheRec->depth++;
1090 /*
1091 * Limit the call depth. (rather arbitrary upper limit; too low and we won't detect certain
1092 * cpuid instructions in Linux kernels; too high and we waste too much time scanning code)
1093 * (512 is necessary to detect cpuid instructions in Red Hat EL4; see defect 1355)
1094 * @note we are using a lot of stack here. couple of 100k when we go to the full depth (!)
1095 */
1096 if (pCacheRec->depth > 512)
1097 {
1098 LogFlow(("CSAM: maximum calldepth reached for %VGv\n", pCurInstrGC));
1099 pCacheRec->depth--;
1100 return VINF_SUCCESS; //let's not go on forever
1101 }
1102
1103 Assert(!PATMIsPatchGCAddr(pVM, pCurInstrGC));
1104 csamR3CheckPageRecord(pVM, pCurInstrGC);
1105
1106 while(rc == VWRN_CONTINUE_ANALYSIS)
1107 {
1108 if (csamIsCodeScanned(pVM, pCurInstrGC, &pPage) == false)
1109 {
1110 if (pPage == NULL)
1111 {
1112 /* New address; let's take a look at it. */
1113 pPage = csamCreatePageRecord(pVM, pCurInstrGC, CSAM_TAG_CSAM, fCode32);
1114 if (pPage == NULL)
1115 {
1116 rc = VERR_NO_MEMORY;
1117 goto done;
1118 }
1119 }
1120 }
1121 else
1122 {
1123 LogFlow(("Code at %VGv has been scanned before\n", pCurInstrGC));
1124 rc = VINF_SUCCESS;
1125 goto done;
1126 }
1127
1128 pCurInstrHC = (uint8_t *)CSAMGCVirtToHCVirt(pVM, pCacheRec, pCurInstrGC);
1129 if (pCurInstrHC == NULL)
1130 {
1131 Log(("CSAMGCVirtToHCVirt failed for %VGv\n", pCurInstrGC));
1132 rc = VERR_PATCHING_REFUSED;
1133 goto done;
1134 }
1135 Assert(VALID_PTR(pCurInstrHC));
1136
1137 cpu.mode = (fCode32) ? CPUMODE_32BIT : CPUMODE_16BIT;
1138 STAM_PROFILE_START(&pVM->csam.s.StatTimeDisasm, a);
1139#ifdef DEBUG
1140 disret = CSAMR3DISInstr(pVM, &cpu, pCurInstrGC, pCurInstrHC, &opsize, szOutput);
1141 if (disret == true) Log(("CSAM Analysis: %s", szOutput));
1142#else
1143 disret = CSAMR3DISInstr(pVM, &cpu, pCurInstrGC, pCurInstrHC, &opsize, NULL);
1144#endif
1145 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeDisasm, a);
1146 if (disret == false)
1147 {
1148 Log(("Disassembly failed at %VGv (probably page not present) -> return to caller\n", pCurInstrGC));
1149 rc = VINF_SUCCESS;
1150 goto done;
1151 }
1152
1153 STAM_COUNTER_ADD(&pVM->csam.s.StatNrBytesRead, opsize);
1154
1155 csamMarkCode(pVM, pPage, pCurInstrGC, opsize, true);
1156
1157 GCPTRTYPE(uint8_t *) addr = 0;
1158 PCSAMPAGE pJmpPage = NULL;
1159
1160 if (PAGE_ADDRESS(pCurInstrGC) != PAGE_ADDRESS(pCurInstrGC + opsize - 1))
1161 {
1162 if (!PGMGstIsPagePresent(pVM, pCurInstrGC + opsize - 1))
1163 {
1164 /// @todo fault in the page
1165 Log(("Page for current instruction %VGv is not present!!\n", pCurInstrGC));
1166 rc = VWRN_CONTINUE_ANALYSIS;
1167 goto next_please;
1168 }
1169 //all is fine, let's continue
1170 csamR3CheckPageRecord(pVM, pCurInstrGC + opsize - 1);
1171 }
1172 /*
1173 * If it's harmless, then don't bother checking it (the disasm tables had better be accurate!)
1174 */
1175 if ((cpu.pCurInstr->optype & ~OPTYPE_RRM_MASK) == OPTYPE_HARMLESS)
1176 {
1177 AssertMsg(pfnCSAMR3Analyse(pVM, &cpu, pInstrGC, pCurInstrGC, pCacheRec, (void *)pPage) == VWRN_CONTINUE_ANALYSIS, ("Instruction incorrectly marked harmless?!?!?\n"));
1178 rc = VWRN_CONTINUE_ANALYSIS;
1179 goto next_please;
1180 }
1181
1182#ifdef CSAM_ANALYSE_BEYOND_RET
1183 /* Remember the address of the instruction following the ret in case the parent instruction was a call. */
1184 if ( pCacheRec->pCallExitRec
1185 && cpu.pCurInstr->opcode == OP_RETN
1186 && pCacheRec->pCallExitRec->cInstrAfterRet < CSAM_MAX_CALLEXIT_RET)
1187 {
1188 pCacheRec->pCallExitRec->pInstrAfterRetGC[pCacheRec->pCallExitRec->cInstrAfterRet] = pCurInstrGC + opsize;
1189 pCacheRec->pCallExitRec->cInstrAfterRet++;
1190 }
1191#endif
1192
1193 rc = pfnCSAMR3Analyse(pVM, &cpu, pInstrGC, pCurInstrGC, pCacheRec, (void *)pPage);
1194 if (rc == VINF_SUCCESS)
1195 goto done;
1196
1197 // For our first attempt, we'll handle only simple relative jumps and calls (immediate offset coded in instruction)
1198 if ((cpu.pCurInstr->optype & OPTYPE_CONTROLFLOW) && (OP_PARM_VTYPE(cpu.pCurInstr->param1) == OP_PARM_J))
1199 {
1200 addr = CSAMResolveBranch(&cpu, pCurInstrGC);
1201 if (addr == 0)
1202 {
1203 Log(("We don't support far jumps here!! (%08X)\n", cpu.param1.flags));
1204 rc = VINF_SUCCESS;
1205 break;
1206 }
1207 Assert(!PATMIsPatchGCAddr(pVM, addr));
1208
1209 /* If the target address lies in a patch generated jump, then special action needs to be taken. */
1210 PATMR3DetectConflict(pVM, pCurInstrGC, addr);
1211
1212 /* Same page? */
1213 if (PAGE_ADDRESS(addr) != PAGE_ADDRESS(pCurInstrGC ))
1214 {
1215 if (!PGMGstIsPagePresent(pVM, addr))
1216 {
1217 Log(("Page for current instruction %VGv is not present!!\n", addr));
1218 rc = VWRN_CONTINUE_ANALYSIS;
1219 goto next_please;
1220 }
1221
1222 /* All is fine, let's continue. */
1223 csamR3CheckPageRecord(pVM, addr);
1224 }
1225
1226 pJmpPage = NULL;
1227 if (csamIsCodeScanned(pVM, addr, &pJmpPage) == false)
1228 {
1229 if (pJmpPage == NULL)
1230 {
1231 /* New branch target; let's take a look at it. */
1232 pJmpPage = csamCreatePageRecord(pVM, addr, CSAM_TAG_CSAM, fCode32);
1233 if (pJmpPage == NULL)
1234 {
1235 rc = VERR_NO_MEMORY;
1236 goto done;
1237 }
1238 Assert(pPage);
1239 }
1240 if (cpu.pCurInstr->opcode == OP_CALL)
1241 rc = csamAnalyseCallCodeStream(pVM, pInstrGC, addr, fCode32, pfnCSAMR3Analyse, (void *)pJmpPage, pCacheRec);
1242 else
1243 rc = csamAnalyseCodeStream(pVM, pInstrGC, addr, fCode32, pfnCSAMR3Analyse, (void *)pJmpPage, pCacheRec);
1244
1245 if (rc != VINF_SUCCESS) {
1246 goto done;
1247 }
1248 }
1249 if (cpu.pCurInstr->opcode == OP_JMP)
1250 {//unconditional jump; return to caller
1251 rc = VINF_SUCCESS;
1252 goto done;
1253 }
1254
1255 rc = VWRN_CONTINUE_ANALYSIS;
1256 } //if ((cpu.pCurInstr->optype & OPTYPE_CONTROLFLOW) && (OP_PARM_VTYPE(cpu.pCurInstr->param1) == OP_PARM_J))
1257#ifdef CSAM_SCAN_JUMP_TABLE
1258 else
1259 if ( cpu.pCurInstr->opcode == OP_JMP
1260 && (cpu.param1.flags & (USE_DISPLACEMENT32|USE_INDEX|USE_SCALE)) == (USE_DISPLACEMENT32|USE_INDEX|USE_SCALE)
1261 )
1262 {
1263 RTGCPTR pJumpTableGC = (RTGCPTR)cpu.param1.disp32;
1264 uint8_t *pJumpTableHC;
1265 int rc2;
1266
1267 Log(("Jump through jump table\n"));
1268
1269 rc2 = PGMPhysGCPtr2HCPtr(pVM, pJumpTableGC, (PRTHCPTR)&pJumpTableHC);
1270 if (rc2 == VINF_SUCCESS)
1271 {
1272 for (uint32_t i=0;i<2;i++)
1273 {
1274 uint64_t fFlags;
1275
1276 addr = pJumpTableGC + cpu.param1.scale * i;
1277 /* Same page? */
1278 if (PAGE_ADDRESS(addr) != PAGE_ADDRESS(pJumpTableGC))
1279 break;
1280
1281 addr = *(RTGCPTR *)(pJumpTableHC + cpu.param1.scale * i);
1282
1283 rc2 = PGMGstGetPage(pVM, addr, &fFlags, NULL);
1284 if ( rc2 != VINF_SUCCESS
1285 || (fFlags & X86_PTE_US)
1286 || !(fFlags & X86_PTE_P)
1287 )
1288 break;
1289
1290 Log(("Jump to %VGv\n", addr));
1291
1292 pJmpPage = NULL;
1293 if (csamIsCodeScanned(pVM, addr, &pJmpPage) == false)
1294 {
1295 if (pJmpPage == NULL)
1296 {
1297 /* New branch target; let's take a look at it. */
1298 pJmpPage = csamCreatePageRecord(pVM, addr, CSAM_TAG_CSAM, fCode32);
1299 if (pJmpPage == NULL)
1300 {
1301 rc = VERR_NO_MEMORY;
1302 goto done;
1303 }
1304 Assert(pPage);
1305 }
1306 rc = csamAnalyseCodeStream(pVM, pInstrGC, addr, fCode32, pfnCSAMR3Analyse, (void *)pJmpPage, pCacheRec);
1307 if (rc != VINF_SUCCESS) {
1308 goto done;
1309 }
1310 }
1311 }
1312 }
1313 }
1314#endif
1315 if (rc != VWRN_CONTINUE_ANALYSIS) {
1316 break; //done!
1317 }
1318next_please:
1319 if (cpu.pCurInstr->opcode == OP_JMP)
1320 {
1321 rc = VINF_SUCCESS;
1322 goto done;
1323 }
1324 pCurInstrGC += opsize;
1325 }
1326done:
1327 pCacheRec->depth--;
1328 return rc;
1329}
1330
1331
1332/**
1333 * Calculates the 64 bits hash value for the current page
1334 *
1335 * @returns hash value
1336 * @param pVM The VM to operate on.
1337 * @param pInstr Page address
1338 */
1339uint64_t csamR3CalcPageHash(PVM pVM, RTGCPTR pInstr)
1340{
1341 uint64_t hash = 0;
1342 uint32_t val[5];
1343 int rc;
1344
1345 Assert((pInstr & PAGE_OFFSET_MASK) == 0);
1346
1347 rc = PGMPhysReadGCPtr(pVM, &val[0], pInstr, sizeof(val[0]));
1348 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
1349 if (rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT)
1350 {
1351 Log(("csamR3CalcPageHash: page %VGv not present!!\n", pInstr));
1352 return ~0ULL;
1353 }
1354
1355 rc = PGMPhysReadGCPtr(pVM, &val[1], pInstr+1024, sizeof(val[0]));
1356 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
1357 if (rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT)
1358 {
1359 Log(("csamR3CalcPageHash: page %VGv not present!!\n", pInstr));
1360 return ~0ULL;
1361 }
1362
1363 rc = PGMPhysReadGCPtr(pVM, &val[2], pInstr+2048, sizeof(val[0]));
1364 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
1365 if (rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT)
1366 {
1367 Log(("csamR3CalcPageHash: page %VGv not present!!\n", pInstr));
1368 return ~0ULL;
1369 }
1370
1371 rc = PGMPhysReadGCPtr(pVM, &val[3], pInstr+3072, sizeof(val[0]));
1372 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
1373 if (rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT)
1374 {
1375 Log(("csamR3CalcPageHash: page %VGv not present!!\n", pInstr));
1376 return ~0ULL;
1377 }
1378
1379 rc = PGMPhysReadGCPtr(pVM, &val[4], pInstr+4092, sizeof(val[0]));
1380 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
1381 if (rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT)
1382 {
1383 Log(("csamR3CalcPageHash: page %VGv not present!!\n", pInstr));
1384 return ~0ULL;
1385 }
1386
1387 // don't want to get division by zero traps
1388 val[2] |= 1;
1389 val[4] |= 1;
1390
1391 hash = (uint64_t)val[0] * (uint64_t)val[1] / (uint64_t)val[2] + (val[3]%val[4]);
1392 return (hash == ~0ULL) ? hash - 1 : hash;
1393}
1394
1395
1396/**
1397 * Notify CSAM of a page flush
1398 *
1399 * @returns VBox status code
1400 * @param pVM The VM to operate on.
1401 * @param addr GC address of the page to flush
1402 * @param fRemovePage Page removal flag
1403 */
1404static int csamFlushPage(PVM pVM, RTGCPTR addr, bool fRemovePage)
1405{
1406 PCSAMPAGEREC pPageRec;
1407 int rc;
1408 RTGCPHYS GCPhys = 0;
1409 uint64_t fFlags = 0;
1410
1411 if (!CSAMIsEnabled(pVM))
1412 return VINF_SUCCESS;
1413
1414 STAM_PROFILE_START(&pVM->csam.s.StatTimeFlushPage, a);
1415
1416 addr = addr & PAGE_BASE_GC_MASK;
1417
1418 /*
1419 * Note: searching for the page in our tree first is more expensive (skipped flushes are two orders of magnitude more common)
1420 */
1421 if (pVM->csam.s.pPageTree == NULL)
1422 {
1423 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeFlushPage, a);
1424 return VWRN_CSAM_PAGE_NOT_FOUND;
1425 }
1426
1427 rc = PGMGstGetPage(pVM, addr, &fFlags, &GCPhys);
1428 /* Returned at a very early stage (no paging yet presumably). */
1429 if (rc == VERR_NOT_SUPPORTED)
1430 {
1431 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeFlushPage, a);
1432 return rc;
1433 }
1434
1435 if (VBOX_SUCCESS(rc))
1436 {
1437 if ( (fFlags & X86_PTE_US)
1438 || rc == VERR_PGM_PHYS_PAGE_RESERVED
1439 )
1440 {
1441 /* User page -> not relevant for us. */
1442 STAM_COUNTER_ADD(&pVM->csam.s.StatNrFlushesSkipped, 1);
1443 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeFlushPage, a);
1444 return VINF_SUCCESS;
1445 }
1446 }
1447 else
1448 if (rc != VERR_PAGE_NOT_PRESENT && rc != VERR_PAGE_TABLE_NOT_PRESENT)
1449 AssertMsgFailed(("PGMR3GetPage %VGv failed with %Vrc\n", addr, rc));
1450
1451 pPageRec = (PCSAMPAGEREC)RTAvlPVGet(&pVM->csam.s.pPageTree, (AVLPVKEY)addr);
1452 if (pPageRec)
1453 {
1454 if ( GCPhys == pPageRec->page.GCPhys
1455 && (fFlags & X86_PTE_P))
1456 {
1457 STAM_COUNTER_ADD(&pVM->csam.s.StatNrFlushesSkipped, 1);
1458 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeFlushPage, a);
1459 return VINF_SUCCESS;
1460 }
1461
1462 Log(("CSAMR3FlushPage: page %VGv has changed -> FLUSH (rc=%Vrc) (Phys: %VGp vs %VGp)\n", addr, rc, GCPhys, pPageRec->page.GCPhys));
1463
1464 STAM_COUNTER_ADD(&pVM->csam.s.StatNrFlushes, 1);
1465
1466 if (fRemovePage)
1467 csamRemovePageRecord(pVM, addr);
1468 else
1469 {
1470 CSAMMarkPage(pVM, addr, false);
1471 pPageRec->page.GCPhys = 0;
1472 pPageRec->page.fFlags = 0;
1473 rc = PGMGstGetPage(pVM, addr, &pPageRec->page.fFlags, &pPageRec->page.GCPhys);
1474 if (rc == VINF_SUCCESS)
1475 pPageRec->page.u64Hash = csamR3CalcPageHash(pVM, addr);
1476
1477 if (pPageRec->page.pBitmap == NULL)
1478 {
1479 pPageRec->page.pBitmap = (uint8_t *)MMR3HeapAllocZ(pVM, MM_TAG_CSAM_PATCH, CSAM_PAGE_BITMAP_SIZE);
1480 Assert(pPageRec->page.pBitmap);
1481 if (pPageRec->page.pBitmap == NULL)
1482 return VERR_NO_MEMORY;
1483 }
1484 else
1485 memset(pPageRec->page.pBitmap, 0, CSAM_PAGE_BITMAP_SIZE);
1486 }
1487
1488
1489 /*
1490 * Inform patch manager about the flush; no need to repeat the above check twice.
1491 */
1492 PATMR3FlushPage(pVM, addr);
1493
1494 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeFlushPage, a);
1495 return VINF_SUCCESS;
1496 }
1497 else
1498 {
1499 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeFlushPage, a);
1500 return VWRN_CSAM_PAGE_NOT_FOUND;
1501 }
1502}
1503
1504/**
1505 * Notify CSAM of a page flush
1506 *
1507 * @returns VBox status code
1508 * @param pVM The VM to operate on.
1509 * @param addr GC address of the page to flush
1510 */
1511CSAMR3DECL(int) CSAMR3FlushPage(PVM pVM, RTGCPTR addr)
1512{
1513 return csamFlushPage(pVM, addr, true /* remove page record */);
1514}
1515
1516/**
1517 * Remove a CSAM monitored page. Use with care!
1518 *
1519 * @returns VBox status code
1520 * @param pVM The VM to operate on.
1521 * @param addr GC address of the page to flush
1522 */
1523CSAMR3DECL(int) CSAMR3RemovePage(PVM pVM, RTGCPTR addr)
1524{
1525 PCSAMPAGEREC pPageRec;
1526 int rc;
1527
1528 addr = addr & PAGE_BASE_GC_MASK;
1529
1530 pPageRec = (PCSAMPAGEREC)RTAvlPVGet(&pVM->csam.s.pPageTree, (AVLPVKEY)addr);
1531 if (pPageRec)
1532 {
1533 rc = csamRemovePageRecord(pVM, addr);
1534 if (VBOX_SUCCESS(rc))
1535 PATMR3FlushPage(pVM, addr);
1536 return VINF_SUCCESS;
1537 }
1538 return VWRN_CSAM_PAGE_NOT_FOUND;
1539}
1540
1541/**
1542 * Check a page record in case a page has been changed
1543 *
1544 * @returns VBox status code. (trap handled or not)
1545 * @param pVM The VM to operate on.
1546 * @param pInstrGC GC instruction pointer
1547 */
1548int csamR3CheckPageRecord(PVM pVM, RTGCPTR pInstrGC)
1549{
1550 PCSAMPAGEREC pPageRec;
1551 uint64_t u64hash;
1552
1553 pInstrGC = pInstrGC & PAGE_BASE_GC_MASK;
1554
1555 pPageRec = (PCSAMPAGEREC)RTAvlPVGet(&pVM->csam.s.pPageTree, (AVLPVKEY)pInstrGC);
1556 if (pPageRec)
1557 {
1558 u64hash = csamR3CalcPageHash(pVM, pInstrGC);
1559 if (u64hash != pPageRec->page.u64Hash)
1560 csamFlushPage(pVM, pInstrGC, false /* don't remove page record */);
1561 }
1562 else
1563 return VWRN_CSAM_PAGE_NOT_FOUND;
1564
1565 return VINF_SUCCESS;
1566}
1567
1568/**
1569 * Returns monitor description based on CSAM tag
1570 *
1571 * @return description string
1572 * @param enmTag Owner tag
1573 */
1574const char *csamGetMonitorDescription(CSAMTAG enmTag)
1575{
1576 if (enmTag == CSAM_TAG_PATM)
1577 return "CSAM-PATM self-modifying code monitor handler";
1578 else
1579 if (enmTag == CSAM_TAG_REM)
1580 return "CSAM-REM self-modifying code monitor handler";
1581 Assert(enmTag == CSAM_TAG_CSAM);
1582 return "CSAM self-modifying code monitor handler";
1583}
1584
1585/**
1586 * Adds page record to our lookup tree
1587 *
1588 * @returns CSAMPAGE ptr or NULL if failure
1589 * @param pVM The VM to operate on.
1590 * @param GCPtr Page address
1591 * @param enmTag Owner tag
1592 * @param fCode32 16 or 32 bits code
1593 * @param fMonitorInvalidation Monitor page invalidation flag
1594 */
1595static PCSAMPAGE csamCreatePageRecord(PVM pVM, RTGCPTR GCPtr, CSAMTAG enmTag, bool fCode32, bool fMonitorInvalidation)
1596{
1597 PCSAMPAGEREC pPage;
1598 int rc;
1599 bool ret;
1600
1601 Log(("New page record for %VGv\n", GCPtr & PAGE_BASE_GC_MASK));
1602
1603 pPage = (PCSAMPAGEREC)MMR3HeapAllocZ(pVM, MM_TAG_CSAM_PATCH, sizeof(CSAMPAGEREC));
1604 if (pPage == NULL)
1605 {
1606 AssertMsgFailed(("csamCreatePageRecord: Out of memory!!!!\n"));
1607 return NULL;
1608 }
1609 /* Round down to page boundary. */
1610 GCPtr = (GCPtr & PAGE_BASE_GC_MASK);
1611 pPage->Core.Key = (AVLPVKEY)GCPtr;
1612 pPage->page.pPageGC = GCPtr;
1613 pPage->page.fCode32 = fCode32;
1614 pPage->page.fMonitorInvalidation = fMonitorInvalidation;
1615 pPage->page.enmTag = enmTag;
1616 pPage->page.fMonitorActive = false;
1617 pPage->page.pBitmap = (uint8_t *)MMR3HeapAllocZ(pVM, MM_TAG_CSAM_PATCH, PAGE_SIZE/sizeof(uint8_t));
1618 rc = PGMGstGetPage(pVM, GCPtr, &pPage->page.fFlags, &pPage->page.GCPhys);
1619 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
1620
1621 pPage->page.u64Hash = csamR3CalcPageHash(pVM, GCPtr);
1622 ret = RTAvlPVInsert(&pVM->csam.s.pPageTree, &pPage->Core);
1623 Assert(ret);
1624
1625#ifdef CSAM_MONITOR_CODE_PAGES
1626 AssertRelease(!fInCSAMCodePageInvalidate);
1627
1628 switch (enmTag)
1629 {
1630 case CSAM_TAG_PATM:
1631 case CSAM_TAG_REM:
1632#ifdef CSAM_MONITOR_CSAM_CODE_PAGES
1633 case CSAM_TAG_CSAM:
1634#endif
1635 {
1636 int rc = PGMR3HandlerVirtualRegister(pVM, PGMVIRTHANDLERTYPE_WRITE, GCPtr, GCPtr + (PAGE_SIZE - 1) /* inclusive! */,
1637 (fMonitorInvalidation) ? CSAMCodePageInvalidate : 0, CSAMCodePageWriteHandler, "CSAMGCCodePageWriteHandler", 0,
1638 csamGetMonitorDescription(enmTag));
1639 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PGM_HANDLER_VIRTUAL_CONFLICT, ("PGMR3HandlerVirtualRegisterEx %VGv failed with %Vrc\n", GCPtr, rc));
1640 if (VBOX_FAILURE(rc))
1641 Log(("PGMR3HandlerVirtualRegisterEx for %VGv failed with %Vrc\n", GCPtr, rc));
1642
1643 /* Could fail, because it's already monitored. Don't treat that condition as fatal. */
1644
1645 /* Prefetch it in case it's not there yet. */
1646 rc = PGMPrefetchPage(pVM, GCPtr);
1647 AssertRC(rc);
1648
1649 rc = PGMShwModifyPage(pVM, GCPtr, 1, 0, ~(uint64_t)X86_PTE_RW);
1650 Assert(rc == VINF_SUCCESS || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT);
1651
1652 pPage->page.fMonitorActive = true;
1653 STAM_COUNTER_INC(&pVM->csam.s.StatPageMonitor);
1654 break;
1655 }
1656 default:
1657 break; /* to shut up GCC */
1658 }
1659
1660 Log(("csamCreatePageRecord %VGv HCPhys=%VGp\n", GCPtr, pPage->page.GCPhys));
1661
1662#ifdef VBOX_WITH_STATISTICS
1663 switch (enmTag)
1664 {
1665 case CSAM_TAG_CSAM:
1666 STAM_COUNTER_INC(&pVM->csam.s.StatPageCSAM);
1667 break;
1668 case CSAM_TAG_PATM:
1669 STAM_COUNTER_INC(&pVM->csam.s.StatPagePATM);
1670 break;
1671 case CSAM_TAG_REM:
1672 STAM_COUNTER_INC(&pVM->csam.s.StatPageREM);
1673 break;
1674 default:
1675 break; /* to shut up GCC */
1676 }
1677#endif
1678
1679#endif
1680
1681 STAM_COUNTER_INC(&pVM->csam.s.StatNrPages);
1682 if (fMonitorInvalidation)
1683 STAM_COUNTER_INC(&pVM->csam.s.StatNrPagesInv);
1684
1685 return &pPage->page;
1686}
1687
1688/**
1689 * Monitors a code page (if not already monitored)
1690 *
1691 * @returns VBox status code
1692 * @param pVM The VM to operate on.
1693 * @param pPageAddrGC The page to monitor
1694 * @param enmTag Monitor tag
1695 */
1696CSAMR3DECL(int) CSAMR3MonitorPage(PVM pVM, RTGCPTR pPageAddrGC, CSAMTAG enmTag)
1697{
1698 PCSAMPAGEREC pPageRec = NULL;
1699 int rc;
1700 bool fMonitorInvalidation;
1701
1702 /* Dirty pages must be handled before calling this function!. */
1703 Assert(!pVM->csam.s.cDirtyPages);
1704
1705 if (pVM->csam.s.fScanningStarted == false)
1706 return VINF_SUCCESS; /* too early */
1707
1708 pPageAddrGC &= PAGE_BASE_GC_MASK;
1709
1710 Log(("CSAMR3MonitorPage %VGv %d\n", pPageAddrGC, enmTag));
1711
1712 /** @todo implicit assumption */
1713 fMonitorInvalidation = (enmTag == CSAM_TAG_PATM);
1714
1715 pPageRec = (PCSAMPAGEREC)RTAvlPVGet(&pVM->csam.s.pPageTree, (AVLPVKEY)pPageAddrGC);
1716 if (pPageRec == NULL)
1717 {
1718 uint64_t fFlags;
1719
1720 rc = PGMGstGetPage(pVM, pPageAddrGC, &fFlags, NULL);
1721 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
1722 if ( rc == VINF_SUCCESS
1723 && (fFlags & X86_PTE_US))
1724 {
1725 /* We don't care about user pages. */
1726 STAM_COUNTER_INC(&pVM->csam.s.StatNrUserPages);
1727 return VINF_SUCCESS;
1728 }
1729
1730 csamCreatePageRecord(pVM, pPageAddrGC, enmTag, true /* 32 bits code */, fMonitorInvalidation);
1731
1732 pPageRec = (PCSAMPAGEREC)RTAvlPVGet(&pVM->csam.s.pPageTree, (AVLPVKEY)pPageAddrGC);
1733 Assert(pPageRec);
1734 }
1735 /** @todo reference count */
1736
1737#ifdef CSAM_MONITOR_CSAM_CODE_PAGES
1738 Assert(pPageRec->page.fMonitorActive);
1739#endif
1740
1741#ifdef CSAM_MONITOR_CODE_PAGES
1742 if (!pPageRec->page.fMonitorActive)
1743 {
1744 Log(("CSAMR3MonitorPage: activate monitoring for %VGv\n", pPageAddrGC));
1745
1746 rc = PGMR3HandlerVirtualRegister(pVM, PGMVIRTHANDLERTYPE_WRITE, pPageAddrGC, pPageAddrGC + (PAGE_SIZE - 1) /* inclusive! */,
1747 (fMonitorInvalidation) ? CSAMCodePageInvalidate : 0, CSAMCodePageWriteHandler, "CSAMGCCodePageWriteHandler", 0,
1748 csamGetMonitorDescription(enmTag));
1749 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PGM_HANDLER_VIRTUAL_CONFLICT, ("PGMR3HandlerVirtualRegisterEx %VGv failed with %Vrc\n", pPageAddrGC, rc));
1750 if (VBOX_FAILURE(rc))
1751 Log(("PGMR3HandlerVirtualRegisterEx for %VGv failed with %Vrc\n", pPageAddrGC, rc));
1752
1753 /* Could fail, because it's already monitored. Don't treat that condition as fatal. */
1754
1755 /* Prefetch it in case it's not there yet. */
1756 rc = PGMPrefetchPage(pVM, pPageAddrGC);
1757 AssertRC(rc);
1758
1759 rc = PGMShwModifyPage(pVM, pPageAddrGC, 1, 0, ~(uint64_t)X86_PTE_RW);
1760 Assert(rc == VINF_SUCCESS || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT);
1761
1762 STAM_COUNTER_INC(&pVM->csam.s.StatPageMonitor);
1763
1764 pPageRec->page.fMonitorActive = true;
1765 pPageRec->page.fMonitorInvalidation = fMonitorInvalidation;
1766 }
1767 else
1768 if ( !pPageRec->page.fMonitorInvalidation
1769 && fMonitorInvalidation)
1770 {
1771 Assert(pPageRec->page.fMonitorActive);
1772 PGMHandlerVirtualChangeInvalidateCallback(pVM, pPageRec->page.pPageGC, CSAMCodePageInvalidate);
1773 pPageRec->page.fMonitorInvalidation = true;
1774 STAM_COUNTER_INC(&pVM->csam.s.StatNrPagesInv);
1775
1776 /* Prefetch it in case it's not there yet. */
1777 rc = PGMPrefetchPage(pVM, pPageAddrGC);
1778 AssertRC(rc);
1779
1780 /* Make sure it's readonly. Page invalidation may have modified the attributes. */
1781 rc = PGMShwModifyPage(pVM, pPageAddrGC, 1, 0, ~(uint64_t)X86_PTE_RW);
1782 Assert(rc == VINF_SUCCESS || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT);
1783 }
1784
1785#if 0 /* def VBOX_STRICT -> very annoying) */
1786 if (pPageRec->page.fMonitorActive)
1787 {
1788 uint64_t fPageShw;
1789 RTHCPHYS GCPhys;
1790 rc = PGMShwGetPage(pVM, pPageAddrGC, &fPageShw, &GCPhys);
1791// AssertMsg( (rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT)
1792// || !(fPageShw & X86_PTE_RW)
1793// || (pPageRec->page.GCPhys == 0), ("Shadow page flags for %VGv (%VHp) aren't readonly (%VX64)!!\n", pPageAddrGC, GCPhys, fPageShw));
1794 }
1795#endif
1796
1797 if (pPageRec->page.GCPhys == 0)
1798 {
1799 /* Prefetch it in case it's not there yet. */
1800 rc = PGMPrefetchPage(pVM, pPageAddrGC);
1801 AssertRC(rc);
1802 /* The page was changed behind our back. It won't be made read-only until the next SyncCR3, so force it here. */
1803 rc = PGMShwModifyPage(pVM, pPageAddrGC, 1, 0, ~(uint64_t)X86_PTE_RW);
1804 Assert(rc == VINF_SUCCESS || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT);
1805 }
1806#endif /* CSAM_MONITOR_CODE_PAGES */
1807 return VINF_SUCCESS;
1808}
1809
1810/**
1811 * Removes a page record from our lookup tree
1812 *
1813 * @returns VBox status code
1814 * @param pVM The VM to operate on.
1815 * @param GCPtr Page address
1816 */
1817static int csamRemovePageRecord(PVM pVM, RTGCPTR GCPtr)
1818{
1819 PCSAMPAGEREC pPageRec;
1820
1821 Log(("csamRemovePageRecord %VGv\n", GCPtr));
1822 pPageRec = (PCSAMPAGEREC)RTAvlPVRemove(&pVM->csam.s.pPageTree, (AVLPVKEY)GCPtr);
1823
1824 if (pPageRec)
1825 {
1826 STAM_COUNTER_INC(&pVM->csam.s.StatNrRemovedPages);
1827
1828#ifdef CSAM_MONITOR_CODE_PAGES
1829 if (pPageRec->page.fMonitorActive)
1830 {
1831 /* @todo -> this is expensive (cr3 reload)!!!
1832 * if this happens often, then reuse it instead!!!
1833 */
1834 Assert(!fInCSAMCodePageInvalidate);
1835 STAM_COUNTER_DEC(&pVM->csam.s.StatPageMonitor);
1836 PGMHandlerVirtualDeregister(pVM, GCPtr);
1837 }
1838 if (pPageRec->page.enmTag == CSAM_TAG_PATM)
1839 {
1840 /* Make sure the recompiler flushes its cache as this page is no longer monitored. */
1841 STAM_COUNTER_INC(&pVM->csam.s.StatPageRemoveREMFlush);
1842 CPUMSetChangedFlags(pVM, CPUM_CHANGED_GLOBAL_TLB_FLUSH);
1843 }
1844#endif
1845
1846#ifdef VBOX_WITH_STATISTICS
1847 switch (pPageRec->page.enmTag)
1848 {
1849 case CSAM_TAG_CSAM:
1850 STAM_COUNTER_DEC(&pVM->csam.s.StatPageCSAM);
1851 break;
1852 case CSAM_TAG_PATM:
1853 STAM_COUNTER_DEC(&pVM->csam.s.StatPagePATM);
1854 break;
1855 case CSAM_TAG_REM:
1856 STAM_COUNTER_DEC(&pVM->csam.s.StatPageREM);
1857 break;
1858 default:
1859 break; /* to shut up GCC */
1860 }
1861#endif
1862
1863 if (pPageRec->page.pBitmap) MMR3HeapFree(pPageRec->page.pBitmap);
1864 MMR3HeapFree(pPageRec);
1865 }
1866 else
1867 AssertFailed();
1868
1869 return VINF_SUCCESS;
1870}
1871
1872/**
1873 * Callback for delayed writes from non-EMT threads
1874 *
1875 * @param pVM VM Handle.
1876 * @param GCPtr The virtual address the guest is writing to. (not correct if it's an alias!)
1877 * @param cbBuf How much it's reading/writing.
1878 */
1879static DECLCALLBACK(void) CSAMDelayedWriteHandler(PVM pVM, RTGCPTR GCPtr, size_t cbBuf)
1880{
1881 int rc = PATMR3PatchWrite(pVM, GCPtr, cbBuf);
1882 AssertRC(rc);
1883}
1884
1885/**
1886 * #PF Handler callback for virtual access handler ranges.
1887 *
1888 * Important to realize that a physical page in a range can have aliases, and
1889 * for ALL and WRITE handlers these will also trigger.
1890 *
1891 * @returns VINF_SUCCESS if the handler have carried out the operation.
1892 * @returns VINF_PGM_HANDLER_DO_DEFAULT if the caller should carry out the access operation.
1893 * @param pVM VM Handle.
1894 * @param GCPtr The virtual address the guest is writing to. (not correct if it's an alias!)
1895 * @param pvPtr The HC mapping of that address.
1896 * @param pvBuf What the guest is reading/writing.
1897 * @param cbBuf How much it's reading/writing.
1898 * @param enmAccessType The access type.
1899 * @param pvUser User argument.
1900 */
1901static DECLCALLBACK(int) CSAMCodePageWriteHandler(PVM pVM, RTGCPTR GCPtr, void *pvPtr, void *pvBuf, size_t cbBuf, PGMACCESSTYPE enmAccessType, void *pvUser)
1902{
1903 int rc;
1904
1905 Assert(enmAccessType == PGMACCESSTYPE_WRITE);
1906 Log(("CSAMCodePageWriteHandler: write to %VGv size=%d\n", GCPtr, cbBuf));
1907
1908 if (VM_IS_EMT(pVM))
1909 {
1910 rc = PATMR3PatchWrite(pVM, GCPtr, cbBuf);
1911 }
1912 else
1913 {
1914 /* Queue the write instead otherwise we'll get concurrency issues. */
1915 /** @note in theory not correct to let it write the data first before disabling a patch!
1916 * (if it writes the same data as the patch jump and we replace it with obsolete opcodes)
1917 */
1918 Log(("CSAMCodePageWriteHandler: delayed write!\n"));
1919 rc = VMR3ReqCallEx(pVM, NULL, 0, VMREQFLAGS_NO_WAIT | VMREQFLAGS_VOID,
1920 (PFNRT)CSAMDelayedWriteHandler, 3, pVM, GCPtr, cbBuf);
1921 }
1922 AssertRC(rc);
1923
1924 return VINF_PGM_HANDLER_DO_DEFAULT;
1925}
1926
1927/**
1928 * #PF Handler callback for invalidation of virtual access handler ranges.
1929 *
1930 * @param pVM VM Handle.
1931 * @param GCPtr The virtual address the guest has changed.
1932 */
1933static DECLCALLBACK(int) CSAMCodePageInvalidate(PVM pVM, RTGCPTR GCPtr)
1934{
1935 fInCSAMCodePageInvalidate = true;
1936 LogFlow(("CSAMCodePageInvalidate %VGv\n", GCPtr));
1937 /** @todo We can't remove the page (which unregisters the virtual handler) as we are called from a DoWithAll on the virtual handler tree. Argh. */
1938 csamFlushPage(pVM, GCPtr, false /* don't remove page! */);
1939 fInCSAMCodePageInvalidate = false;
1940 return VINF_SUCCESS;
1941}
1942
1943/**
1944 * Check if the current instruction has already been checked before
1945 *
1946 * @returns VBox status code. (trap handled or not)
1947 * @param pVM The VM to operate on.
1948 * @param pInstr Instruction pointer
1949 * @param pPage CSAM patch structure pointer
1950 */
1951bool csamIsCodeScanned(PVM pVM, RTGCPTR pInstr, PCSAMPAGE *pPage)
1952{
1953 PCSAMPAGEREC pPageRec;
1954 uint32_t offset;
1955
1956 STAM_PROFILE_START(&pVM->csam.s.StatTimeCheckAddr, a);
1957
1958 offset = pInstr & PAGE_OFFSET_MASK;
1959 pInstr = pInstr & PAGE_BASE_GC_MASK;
1960
1961 Assert(pPage);
1962
1963 if (*pPage && (*pPage)->pPageGC == pInstr)
1964 {
1965 if ((*pPage)->pBitmap == NULL || ASMBitTest((*pPage)->pBitmap, offset))
1966 {
1967 STAM_COUNTER_ADD(&pVM->csam.s.StatNrKnownPagesHC, 1);
1968 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeCheckAddr, a);
1969 return true;
1970 }
1971 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeCheckAddr, a);
1972 return false;
1973 }
1974
1975 pPageRec = (PCSAMPAGEREC)RTAvlPVGet(&pVM->csam.s.pPageTree, (AVLPVKEY)pInstr);
1976 if (pPageRec)
1977 {
1978 if (pPage) *pPage= &pPageRec->page;
1979 if (pPageRec->page.pBitmap == NULL || ASMBitTest(pPageRec->page.pBitmap, offset))
1980 {
1981 STAM_COUNTER_ADD(&pVM->csam.s.StatNrKnownPagesHC, 1);
1982 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeCheckAddr, a);
1983 return true;
1984 }
1985 }
1986 else
1987 {
1988 if (pPage) *pPage = NULL;
1989 }
1990 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeCheckAddr, a);
1991 return false;
1992}
1993
1994/**
1995 * Mark an instruction in a page as scanned/not scanned
1996 *
1997 * @param pVM The VM to operate on.
1998 * @param pPage Patch structure pointer
1999 * @param pInstr Instruction pointer
2000 * @param opsize Instruction size
2001 * @param fScanned Mark as scanned or not
2002 */
2003static void csamMarkCode(PVM pVM, PCSAMPAGE pPage, RTGCPTR pInstr, uint32_t opsize, bool fScanned)
2004{
2005 LogFlow(("csamMarkCodeAsScanned %VGv opsize=%d\n", pInstr, opsize));
2006 CSAMMarkPage(pVM, pInstr, fScanned);
2007
2008 /** @todo should recreate empty bitmap if !fScanned */
2009 if (pPage->pBitmap == NULL)
2010 return;
2011
2012 if (fScanned)
2013 {
2014 // retn instructions can be scanned more than once
2015 if (ASMBitTest(pPage->pBitmap, pInstr & PAGE_OFFSET_MASK) == 0)
2016 {
2017 pPage->uSize += opsize;
2018 STAM_COUNTER_ADD(&pVM->csam.s.StatNrInstr, 1);
2019 }
2020 if (pPage->uSize >= PAGE_SIZE)
2021 {
2022 Log(("Scanned full page (%VGv) -> free bitmap\n", pInstr & PAGE_BASE_GC_MASK));
2023 MMR3HeapFree(pPage->pBitmap);
2024 pPage->pBitmap = NULL;
2025 }
2026 else
2027 ASMBitSet(pPage->pBitmap, pInstr & PAGE_OFFSET_MASK);
2028 }
2029 else
2030 ASMBitClear(pPage->pBitmap, pInstr & PAGE_OFFSET_MASK);
2031}
2032
2033/**
2034 * Mark an instruction in a page as scanned/not scanned
2035 *
2036 * @returns VBox status code.
2037 * @param pVM The VM to operate on.
2038 * @param pInstr Instruction pointer
2039 * @param opsize Instruction size
2040 * @param fScanned Mark as scanned or not
2041 */
2042CSAMR3DECL(int) CSAMR3MarkCode(PVM pVM, RTGCPTR pInstr, uint32_t opsize, bool fScanned)
2043{
2044 PCSAMPAGE pPage = 0;
2045
2046 Assert(!fScanned); /* other case not implemented. */
2047 Assert(!PATMIsPatchGCAddr(pVM, pInstr));
2048
2049 if (csamIsCodeScanned(pVM, pInstr, &pPage) == false)
2050 {
2051 Assert(fScanned == true); /* other case should not be possible */
2052 return VINF_SUCCESS;
2053 }
2054
2055 Log(("CSAMR3MarkCode: %VGv size=%d fScanned=%d\n", pInstr, opsize, fScanned));
2056 csamMarkCode(pVM, pPage, pInstr, opsize, fScanned);
2057 return VINF_SUCCESS;
2058}
2059
2060
2061/**
2062 * Scan and analyse code
2063 *
2064 * @returns VBox status code.
2065 * @param pVM The VM to operate on.
2066 * @param Sel selector
2067 * @param pHiddenSel The hidden selector register.
2068 * @param pInstrGC Instruction pointer
2069 */
2070CSAMR3DECL(int) CSAMR3CheckCodeEx(PVM pVM, RTSEL Sel, CPUMSELREGHID *pHiddenSel, RTGCPTR pInstrGC)
2071{
2072 if (EMIsRawRing0Enabled(pVM) == false || PATMIsPatchGCAddr(pVM, pInstrGC) == true)
2073 {
2074 // No use
2075 return VINF_SUCCESS;
2076 }
2077
2078 if (CSAMIsEnabled(pVM))
2079 {
2080 X86EFLAGS fakeflags;
2081
2082 /* we're not in v86 mode here */
2083 fakeflags.u32 = 0;
2084
2085 bool fCode32 = SELMIsSelector32Bit(pVM, fakeflags, Sel, pHiddenSel);
2086
2087 //assuming 32 bits code for now
2088 Assert(fCode32); NOREF(fCode32);
2089
2090 pInstrGC = SELMToFlat(pVM, fakeflags, Sel, pHiddenSel, pInstrGC);
2091
2092 return CSAMR3CheckCode(pVM, pInstrGC);
2093 }
2094 return VINF_SUCCESS;
2095}
2096
2097/**
2098 * Scan and analyse code
2099 *
2100 * @returns VBox status code.
2101 * @param pVM The VM to operate on.
2102 * @param pInstrGC Instruction pointer (0:32 virtual address)
2103 */
2104CSAMR3DECL(int) CSAMR3CheckCode(PVM pVM, RTGCPTR pInstrGC)
2105{
2106 int rc;
2107 PCSAMPAGE pPage = NULL;
2108
2109 if (EMIsRawRing0Enabled(pVM) == false || PATMIsPatchGCAddr(pVM, pInstrGC) == true)
2110 {
2111 // No use
2112 return VINF_SUCCESS;
2113 }
2114
2115 if (CSAMIsEnabled(pVM))
2116 {
2117 // Cache record for PATMGCVirtToHCVirt
2118 CSAMP2GLOOKUPREC cacheRec = {0};
2119
2120 STAM_PROFILE_START(&pVM->csam.s.StatTime, a);
2121 rc = csamAnalyseCallCodeStream(pVM, pInstrGC, pInstrGC, true /* 32 bits code */, CSAMR3AnalyseCallback, pPage, &cacheRec);
2122 STAM_PROFILE_STOP(&pVM->csam.s.StatTime, a);
2123 if (rc != VINF_SUCCESS)
2124 {
2125 Log(("csamAnalyseCodeStream failed with %d\n", rc));
2126 return rc;
2127 }
2128 }
2129 return VINF_SUCCESS;
2130}
2131
2132/**
2133 * Flush dirty code pages
2134 *
2135 * @returns VBox status code.
2136 * @param pVM The VM to operate on.
2137 */
2138static int csamR3FlushDirtyPages(PVM pVM)
2139{
2140 STAM_PROFILE_START(&pVM->csam.s.StatFlushDirtyPages, a);
2141
2142 for (uint32_t i=0;i<pVM->csam.s.cDirtyPages;i++)
2143 {
2144 int rc;
2145 PCSAMPAGEREC pPageRec;
2146 RTGCPTR GCPtr = pVM->csam.s.pvDirtyBasePage[i];
2147
2148 GCPtr = GCPtr & PAGE_BASE_GC_MASK;
2149
2150 /* Notify the recompiler that this page has been changed. */
2151 REMR3NotifyCodePageChanged(pVM, GCPtr);
2152
2153 /* Enable write protection again. (use the fault address as it might be an alias) */
2154 rc = PGMShwModifyPage(pVM, pVM->csam.s.pvDirtyFaultPage[i], 1, 0, ~(uint64_t)X86_PTE_RW);
2155 Assert(rc == VINF_SUCCESS || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT);
2156
2157 Log(("CSAMR3FlushDirtyPages: flush %VGv (modifypage rc=%Vrc)\n", pVM->csam.s.pvDirtyBasePage[i], rc));
2158
2159 pPageRec = (PCSAMPAGEREC)RTAvlPVGet(&pVM->csam.s.pPageTree, (AVLPVKEY)GCPtr);
2160 if (pPageRec && pPageRec->page.enmTag == CSAM_TAG_REM)
2161 {
2162 uint64_t fFlags;
2163
2164 rc = PGMGstGetPage(pVM, GCPtr, &fFlags, NULL);
2165 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
2166 if ( rc == VINF_SUCCESS
2167 && (fFlags & X86_PTE_US))
2168 {
2169 /* We don't care about user pages. */
2170 csamRemovePageRecord(pVM, GCPtr);
2171 STAM_COUNTER_INC(&pVM->csam.s.StatNrUserPages);
2172 }
2173 }
2174 }
2175 pVM->csam.s.cDirtyPages = 0;
2176 STAM_PROFILE_STOP(&pVM->csam.s.StatFlushDirtyPages, a);
2177 return VINF_SUCCESS;
2178}
2179
2180/**
2181 * Flush potential new code pages
2182 *
2183 * @returns VBox status code.
2184 * @param pVM The VM to operate on.
2185 */
2186static int csamR3FlushCodePages(PVM pVM)
2187{
2188 for (uint32_t i=0;i<pVM->csam.s.cPossibleCodePages;i++)
2189 {
2190 RTGCPTR GCPtr = pVM->csam.s.pvPossibleCodePage[i];
2191
2192 GCPtr = GCPtr & PAGE_BASE_GC_MASK;
2193
2194 Log(("csamR3FlushCodePages: %VGv\n", GCPtr));
2195 PGMShwSetPage(pVM, GCPtr, 1, 0);
2196 /* Resync the page to make sure instruction fetch will fault */
2197 CSAMMarkPage(pVM, GCPtr, false);
2198 }
2199 pVM->csam.s.cPossibleCodePages = 0;
2200 return VINF_SUCCESS;
2201}
2202
2203/**
2204 * Perform any pending actions
2205 *
2206 * @returns VBox status code.
2207 * @param pVM The VM to operate on.
2208 */
2209CSAMR3DECL(int) CSAMR3DoPendingAction(PVM pVM)
2210{
2211 csamR3FlushDirtyPages(pVM);
2212 csamR3FlushCodePages(pVM);
2213
2214 VM_FF_CLEAR(pVM, VM_FF_CSAM_PENDING_ACTION);
2215 return VINF_SUCCESS;
2216}
2217
2218/**
2219 * Analyse interrupt and trap gates
2220 *
2221 * @returns VBox status code.
2222 * @param pVM The VM to operate on.
2223 * @param iGate Start gate
2224 * @param cGates Number of gates to check
2225 */
2226CSAMR3DECL(int) CSAMR3CheckGates(PVM pVM, uint32_t iGate, uint32_t cGates)
2227{
2228 uint16_t cbIDT;
2229 RTGCPTR GCPtrIDT = CPUMGetGuestIDTR(pVM, &cbIDT);
2230 uint32_t iGateEnd;
2231 uint32_t maxGates;
2232 VBOXIDTE aIDT[256];
2233 PVBOXIDTE pGuestIdte;
2234 int rc;
2235
2236 if (EMIsRawRing0Enabled(pVM) == false)
2237 {
2238 /* Enabling interrupt gates only works when raw ring 0 is enabled. */
2239 //AssertFailed();
2240 return VINF_SUCCESS;
2241 }
2242
2243 /* We only check all gates once during a session */
2244 if ( !pVM->csam.s.fGatesChecked
2245 && cGates != 256)
2246 return VINF_SUCCESS; /* too early */
2247
2248 /* We only check all gates once during a session */
2249 if ( pVM->csam.s.fGatesChecked
2250 && cGates != 1)
2251 return VINF_SUCCESS; /* ignored */
2252
2253 Assert(cGates <= 256);
2254 if (!GCPtrIDT || cGates > 256)
2255 return VERR_INVALID_PARAMETER;
2256
2257 if (cGates != 1)
2258 pVM->csam.s.fGatesChecked = true;
2259
2260 /* Determine valid upper boundary. */
2261 maxGates = (cbIDT+1) / sizeof(VBOXIDTE);
2262 Assert(iGate < maxGates);
2263 if (iGate > maxGates)
2264 return VERR_INVALID_PARAMETER;
2265
2266 if (iGate + cGates > maxGates)
2267 cGates = maxGates - iGate;
2268
2269 GCPtrIDT = GCPtrIDT + iGate * sizeof(VBOXIDTE);
2270 iGateEnd = iGate + cGates;
2271
2272 STAM_PROFILE_START(&pVM->csam.s.StatCheckGates, a);
2273
2274 /*
2275 * Get IDT entries.
2276 */
2277 if (PAGE_ADDRESS(GCPtrIDT) == PAGE_ADDRESS(GCPtrIDT+cGates*sizeof(VBOXIDTE)))
2278 {
2279 /* Just convert the IDT address to a HC pointer. The whole IDT fits in one page. */
2280 rc = PGMPhysGCPtr2HCPtr(pVM, GCPtrIDT, (PRTHCPTR)&pGuestIdte);
2281 if (VBOX_FAILURE(rc))
2282 {
2283 AssertMsgRC(rc, ("Failed to read IDTE! rc=%Vrc\n", rc));
2284 STAM_PROFILE_STOP(&pVM->csam.s.StatCheckGates, a);
2285 return rc;
2286 }
2287 }
2288 else
2289 {
2290 /* Slow method when it crosses a page boundary. */
2291 rc = PGMPhysReadGCPtr(pVM, aIDT, GCPtrIDT, cGates*sizeof(VBOXIDTE));
2292 if (VBOX_FAILURE(rc))
2293 {
2294 AssertMsgRC(rc, ("Failed to read IDTE! rc=%Vrc\n", rc));
2295 STAM_PROFILE_STOP(&pVM->csam.s.StatCheckGates, a);
2296 return rc;
2297 }
2298 pGuestIdte = &aIDT[0];
2299 }
2300
2301 for (/*iGate*/; iGate<iGateEnd; iGate++, pGuestIdte++)
2302 {
2303 Assert(TRPMR3GetGuestTrapHandler(pVM, iGate) == TRPM_INVALID_HANDLER);
2304
2305 if ( pGuestIdte->Gen.u1Present
2306 && (pGuestIdte->Gen.u5Type2 == VBOX_IDTE_TYPE2_TRAP_32 || pGuestIdte->Gen.u5Type2 == VBOX_IDTE_TYPE2_INT_32)
2307 && (pGuestIdte->Gen.u2DPL == 3 || pGuestIdte->Gen.u2DPL == 0)
2308 )
2309 {
2310 RTGCPTR pHandler;
2311 CSAMP2GLOOKUPREC cacheRec = {0}; /* Cache record for PATMGCVirtToHCVirt. */
2312 PCSAMPAGE pPage = NULL;
2313 X86EFLAGS fakeflags;
2314 SELMSELINFO selInfo;
2315
2316 /* we're not in v86 mode here */
2317 fakeflags.u32 = 0;
2318
2319 pHandler = (pGuestIdte->Gen.u16OffsetHigh << 16) | pGuestIdte->Gen.u16OffsetLow;
2320 pHandler = SELMToFlat(pVM, fakeflags, pGuestIdte->Gen.u16SegSel, 0, pHandler);
2321
2322 rc = SELMR3GetSelectorInfo(pVM, pGuestIdte->Gen.u16SegSel, &selInfo);
2323 if ( VBOX_FAILURE(rc)
2324 || selInfo.GCPtrBase != 0
2325 || selInfo.cbLimit != ~0U
2326 )
2327 {
2328 /* Refuse to patch a handler whose idt cs selector isn't wide open. */
2329 Log(("CSAMCheckGates: check gate %d failed due to rc %Vrc GCPtrBase=%VGv limit=%x\n", iGate, rc, selInfo.GCPtrBase, selInfo.cbLimit));
2330 continue;
2331 }
2332
2333
2334 if (pGuestIdte->Gen.u5Type2 == VBOX_IDTE_TYPE2_TRAP_32)
2335 {
2336 Log(("CSAMCheckGates: check trap gate %d at %04X:%08X (flat %VGv)\n", iGate, pGuestIdte->Gen.u16SegSel, (pGuestIdte->Gen.u16OffsetHigh << 16) | pGuestIdte->Gen.u16OffsetLow, pHandler));
2337 }
2338 else
2339 {
2340 Log(("CSAMCheckGates: check interrupt gate %d at %04X:%08X (flat %VGv)\n", iGate, pGuestIdte->Gen.u16SegSel, (pGuestIdte->Gen.u16OffsetHigh << 16) | pGuestIdte->Gen.u16OffsetLow, pHandler));
2341 }
2342
2343 STAM_PROFILE_START(&pVM->csam.s.StatTime, a);
2344 rc = csamAnalyseCodeStream(pVM, pHandler, pHandler, true, CSAMR3AnalyseCallback, pPage, &cacheRec);
2345 STAM_PROFILE_STOP(&pVM->csam.s.StatTime, a);
2346 if (rc != VINF_SUCCESS)
2347 {
2348 Log(("CSAMCheckGates: csamAnalyseCodeStream failed with %d\n", rc));
2349 continue;
2350 }
2351 /* OpenBSD guest specific patch test. */
2352 if (iGate >= 0x20)
2353 {
2354 PCPUMCTX pCtx;
2355 DISCPUSTATE cpu;
2356 RTGCUINTPTR aOpenBsdPushCSOffset[3] = {0x03, /* OpenBSD 3.7 & 3.8 */
2357 0x2B, /* OpenBSD 4.0 installation ISO */
2358 0x2F}; /* OpenBSD 4.0 after install */
2359
2360 rc = CPUMQueryGuestCtxPtr(pVM, &pCtx);
2361 AssertRC(rc); /* can't fail */
2362
2363 for (unsigned i=0;i<ELEMENTS(aOpenBsdPushCSOffset);i++)
2364 {
2365 rc = CPUMR3DisasmInstrCPU(pVM, pCtx, pHandler - aOpenBsdPushCSOffset[i], &cpu, NULL);
2366 if ( rc == VINF_SUCCESS
2367 && cpu.pCurInstr->opcode == OP_PUSH
2368 && cpu.pCurInstr->param1 == OP_PARM_REG_CS)
2369 {
2370 rc = PATMR3InstallPatch(pVM, pHandler - aOpenBsdPushCSOffset[i], PATMFL_CODE32 | PATMFL_GUEST_SPECIFIC);
2371 if (VBOX_SUCCESS(rc))
2372 Log(("Installed OpenBSD interrupt handler prefix instruction (push cs) patch\n"));
2373 }
2374 }
2375 }
2376
2377 /* Trap gates and certain interrupt gates. */
2378 uint32_t fPatchFlags = PATMFL_CODE32 | PATMFL_IDTHANDLER;
2379
2380 if (pGuestIdte->Gen.u5Type2 == VBOX_IDTE_TYPE2_TRAP_32)
2381 fPatchFlags |= PATMFL_TRAPHANDLER;
2382 else
2383 fPatchFlags |= PATMFL_INTHANDLER;
2384
2385 switch (iGate) {
2386 case 8:
2387 case 10:
2388 case 11:
2389 case 12:
2390 case 13:
2391 case 14:
2392 case 17:
2393 fPatchFlags |= PATMFL_TRAPHANDLER_WITH_ERRORCODE;
2394 break;
2395 default:
2396 /* No error code. */
2397 break;
2398 }
2399
2400 Log(("Installing %s gate handler for 0x%X at %VGv\n", (pGuestIdte->Gen.u5Type2 == VBOX_IDTE_TYPE2_TRAP_32) ? "trap" : "intr", iGate, pHandler));
2401
2402 rc = PATMR3InstallPatch(pVM, pHandler, fPatchFlags);
2403 if (VBOX_SUCCESS(rc) || rc == VERR_PATM_ALREADY_PATCHED)
2404 {
2405 Log(("Gate handler 0x%X is SAFE!\n", iGate));
2406
2407 RTGCPTR pNewHandlerGC = PATMR3QueryPatchGCPtr(pVM, pHandler);
2408 if (pNewHandlerGC)
2409 {
2410 rc = TRPMR3SetGuestTrapHandler(pVM, iGate, pNewHandlerGC);
2411 if (VBOX_FAILURE(rc))
2412 Log(("TRPMR3SetGuestTrapHandler %d failed with %Vrc\n", iGate, rc));
2413 }
2414 }
2415 }
2416 } /* for */
2417 STAM_PROFILE_STOP(&pVM->csam.s.StatCheckGates, a);
2418 return VINF_SUCCESS;
2419}
2420
2421/**
2422 * Query CSAM state (enabled/disabled)
2423 *
2424 * @returns 0 - disabled, 1 - enabled
2425 * @param pVM The VM to operate on.
2426 */
2427CSAMR3DECL(int) CSAMR3IsEnabled(PVM pVM)
2428{
2429 return pVM->fCSAMEnabled;
2430}
2431
2432#ifdef VBOX_WITH_DEBUGGER
2433/**
2434 * The '.csamoff' command.
2435 *
2436 * @returns VBox status.
2437 * @param pCmd Pointer to the command descriptor (as registered).
2438 * @param pCmdHlp Pointer to command helper functions.
2439 * @param pVM Pointer to the current VM (if any).
2440 * @param paArgs Pointer to (readonly) array of arguments.
2441 * @param cArgs Number of arguments in the array.
2442 */
2443static DECLCALLBACK(int) csamr3CmdOff(PCDBGCCMD pCmd, PDBGCCMDHLP pCmdHlp, PVM pVM, PCDBGCVAR paArgs, unsigned cArgs, PDBGCVAR pResult)
2444{
2445 /*
2446 * Validate input.
2447 */
2448 if (!pVM)
2449 return pCmdHlp->pfnPrintf(pCmdHlp, NULL, "error: The command requires VM to be selected.\n");
2450
2451 CSAMDisableScanning(pVM);
2452 return pCmdHlp->pfnPrintf(pCmdHlp, NULL, "CSAM Scanning disabled\n");
2453}
2454
2455/**
2456 * The '.csamon' command.
2457 *
2458 * @returns VBox status.
2459 * @param pCmd Pointer to the command descriptor (as registered).
2460 * @param pCmdHlp Pointer to command helper functions.
2461 * @param pVM Pointer to the current VM (if any).
2462 * @param paArgs Pointer to (readonly) array of arguments.
2463 * @param cArgs Number of arguments in the array.
2464 */
2465static DECLCALLBACK(int) csamr3CmdOn(PCDBGCCMD pCmd, PDBGCCMDHLP pCmdHlp, PVM pVM, PCDBGCVAR paArgs, unsigned cArgs, PDBGCVAR pResult)
2466{
2467 /*
2468 * Validate input.
2469 */
2470 if (!pVM)
2471 return pCmdHlp->pfnPrintf(pCmdHlp, NULL, "error: The command requires VM to be selected.\n");
2472
2473 CSAMEnableScanning(pVM);
2474 return pCmdHlp->pfnPrintf(pCmdHlp, NULL, "CSAM Scanning enabled\n");
2475}
2476#endif
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