VirtualBox

source: vbox/trunk/src/VBox/VMM/PATM/CSAM.cpp@ 13532

Last change on this file since 13532 was 13532, checked in by vboxsync, 16 years ago

CPUMQueryGuestCtxPtr doesn't need to return a status. It can never fail.

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1/* $Id: CSAM.cpp 13532 2008-10-23 12:39:48Z vboxsync $ */
2/** @file
3 * CSAM - Guest OS Code Scanning and Analysis Manager
4 */
5
6/*
7 * Copyright (C) 2006-2007 Sun Microsystems, Inc.
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 (GPL) as published by the Free Software
13 * Foundation, in version 2 as it comes in the "COPYING" file of the
14 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16 *
17 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
18 * Clara, CA 95054 USA or visit http://www.sun.com if you need
19 * additional information or have any questions.
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, RTRCPTR pInstr, PCSAMPAGE *pPage);
77int csamR3CheckPageRecord(PVM pVM, RTRCPTR pInstr);
78static PCSAMPAGE csamCreatePageRecord(PVM pVM, RTRCPTR GCPtr, CSAMTAG enmTag, bool fCode32, bool fMonitorInvalidation = false);
79static int csamRemovePageRecord(PVM pVM, RTRCPTR GCPtr);
80static int csamReinit(PVM pVM);
81static void csamMarkCode(PVM pVM, PCSAMPAGE pPage, RTRCPTR pInstr, uint32_t opsize, bool fScanned);
82static int csamAnalyseCodeStream(PVM pVM, RCPTRTYPE(uint8_t *) pInstrGC, RCPTRTYPE(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 */
111VMMR3DECL(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(RTRCPTR), 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], RT_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 memset(pVM->csam.s.pvCallInstruction, 0, sizeof(pVM->csam.s.pvCallInstruction));
241 pVM->csam.s.iCallInstruction = 0;
242
243 /** @note never mess with the pgdir bitmap here! */
244 return VINF_SUCCESS;
245}
246
247/**
248 * Applies relocations to data and code managed by this
249 * component. This function will be called at init and
250 * whenever the VMM need to relocate itself inside the GC.
251 *
252 * The csam will update the addresses used by the switcher.
253 *
254 * @param pVM The VM.
255 * @param offDelta Relocation delta.
256 */
257VMMR3DECL(void) CSAMR3Relocate(PVM pVM, RTGCINTPTR offDelta)
258{
259 if (offDelta)
260 {
261 /* Adjust pgdir and page bitmap pointers. */
262 pVM->csam.s.pPDBitmapGC = MMHyperHC2GC(pVM, pVM->csam.s.pPDGCBitmapHC);
263 pVM->csam.s.pPDHCBitmapGC = MMHyperHC2GC(pVM, pVM->csam.s.pPDBitmapHC);
264
265 for(int i=0;i<CSAM_PGDIRBMP_CHUNKS;i++)
266 {
267 if (pVM->csam.s.pPDGCBitmapHC[i])
268 {
269 pVM->csam.s.pPDGCBitmapHC[i] += offDelta;
270 }
271 }
272 }
273 return;
274}
275
276/**
277 * Terminates the csam.
278 *
279 * Termination means cleaning up and freeing all resources,
280 * the VM it self is at this point powered off or suspended.
281 *
282 * @returns VBox status code.
283 * @param pVM The VM to operate on.
284 */
285VMMR3DECL(int) CSAMR3Term(PVM pVM)
286{
287 int rc;
288
289 rc = CSAMR3Reset(pVM);
290 AssertRC(rc);
291
292 /* @todo triggers assertion in MMHyperFree */
293#if 0
294 for(int i=0;i<CSAM_PAGEBMP_CHUNKS;i++)
295 {
296 if (pVM->csam.s.pPDBitmapHC[i])
297 MMHyperFree(pVM, pVM->csam.s.pPDBitmapHC[i]);
298 }
299#endif
300
301 return VINF_SUCCESS;
302}
303
304/**
305 * CSAM reset callback.
306 *
307 * @returns VBox status code.
308 * @param pVM The VM which is reset.
309 */
310VMMR3DECL(int) CSAMR3Reset(PVM pVM)
311{
312 /* Clear page bitmaps. */
313 for(int i=0;i<CSAM_PGDIRBMP_CHUNKS;i++)
314 {
315 if (pVM->csam.s.pPDBitmapHC[i])
316 {
317 Assert((CSAM_PAGE_BITMAP_SIZE& 3) == 0);
318 ASMMemZero32(pVM->csam.s.pPDBitmapHC[i], CSAM_PAGE_BITMAP_SIZE);
319 }
320 }
321
322 /* Remove all CSAM page records. */
323 while(true)
324 {
325 PCSAMPAGEREC pPageRec = (PCSAMPAGEREC)RTAvlPVGetBestFit(&pVM->csam.s.pPageTree, 0, true);
326 if (pPageRec)
327 {
328 csamRemovePageRecord(pVM, pPageRec->page.pPageGC);
329 }
330 else
331 break;
332 }
333 Assert(!pVM->csam.s.pPageTree);
334
335 csamReinit(pVM);
336
337 return VINF_SUCCESS;
338}
339
340#define CSAM_SUBTRACT_PTR(a, b) *(uintptr_t *)&(a) = (uintptr_t)(a) - (uintptr_t)(b)
341#define CSAM_ADD_PTR(a, b) *(uintptr_t *)&(a) = (uintptr_t)(a) + (uintptr_t)(b)
342
343
344/**
345 * Callback function for RTAvlPVDoWithAll
346 *
347 * Counts the number of records in the tree
348 *
349 * @returns VBox status code.
350 * @param pNode Current node
351 * @param pcPatches Pointer to patch counter
352 */
353static DECLCALLBACK(int) CountRecord(PAVLPVNODECORE pNode, void *pcPatches)
354{
355 *(uint32_t *)pcPatches = *(uint32_t *)pcPatches + 1;
356 return VINF_SUCCESS;
357}
358
359/**
360 * Callback function for RTAvlPVDoWithAll
361 *
362 * Saves the state of the page record
363 *
364 * @returns VBox status code.
365 * @param pNode Current node
366 * @param pVM1 VM Handle
367 */
368static DECLCALLBACK(int) SavePageState(PAVLPVNODECORE pNode, void *pVM1)
369{
370 PVM pVM = (PVM)pVM1;
371 PCSAMPAGEREC pPage = (PCSAMPAGEREC)pNode;
372 CSAMPAGEREC page = *pPage;
373 PSSMHANDLE pSSM = pVM->csam.s.savedstate.pSSM;
374 int rc;
375
376 /* Save the page record itself */
377 rc = SSMR3PutMem(pSSM, &page, sizeof(page));
378 AssertRCReturn(rc, rc);
379
380 if (page.page.pBitmap)
381 {
382 rc = SSMR3PutMem(pSSM, page.page.pBitmap, CSAM_PAGE_BITMAP_SIZE);
383 AssertRCReturn(rc, rc);
384 }
385
386 return VINF_SUCCESS;
387}
388
389/**
390 * Execute state save operation.
391 *
392 * @returns VBox status code.
393 * @param pVM VM Handle.
394 * @param pSSM SSM operation handle.
395 */
396static DECLCALLBACK(int) csamr3Save(PVM pVM, PSSMHANDLE pSSM)
397{
398 CSAM csamInfo = pVM->csam.s;
399 int rc;
400
401 /*
402 * Count the number of page records in the tree (feeling lazy)
403 */
404 csamInfo.savedstate.cPageRecords = 0;
405 RTAvlPVDoWithAll(&pVM->csam.s.pPageTree, true, CountRecord, &csamInfo.savedstate.cPageRecords);
406
407 /*
408 * Save CSAM structure
409 */
410 pVM->csam.s.savedstate.pSSM = pSSM;
411 rc = SSMR3PutMem(pSSM, &csamInfo, sizeof(csamInfo));
412 AssertRCReturn(rc, rc);
413
414 /* Save pgdir bitmap */
415 rc = SSMR3PutMem(pSSM, csamInfo.pPDBitmapHC, CSAM_PGDIRBMP_CHUNKS*sizeof(RTHCPTR));
416 AssertRCReturn(rc, rc);
417
418 for (unsigned i=0;i<CSAM_PGDIRBMP_CHUNKS;i++)
419 {
420 if(csamInfo.pPDBitmapHC[i])
421 {
422 /* Save the page bitmap. */
423 rc = SSMR3PutMem(pSSM, csamInfo.pPDBitmapHC[i], CSAM_PAGE_BITMAP_SIZE);
424 AssertRCReturn(rc, rc);
425 }
426 }
427
428 /*
429 * Save page records
430 */
431 rc = RTAvlPVDoWithAll(&pVM->csam.s.pPageTree, true, SavePageState, pVM);
432 AssertRCReturn(rc, rc);
433
434 /** @note we don't restore aDangerousInstr; it will be recreated automatically. */
435 return VINF_SUCCESS;
436}
437
438/**
439 * Execute state load operation.
440 *
441 * @returns VBox status code.
442 * @param pVM VM Handle.
443 * @param pSSM SSM operation handle.
444 * @param u32Version Data layout version.
445 */
446static DECLCALLBACK(int) csamr3Load(PVM pVM, PSSMHANDLE pSSM, uint32_t u32Version)
447{
448 int rc;
449 CSAM csamInfo;
450
451 if (u32Version != CSAM_SSM_VERSION)
452 {
453 AssertMsgFailed(("csamR3Load: Invalid version u32Version=%d!\n", u32Version));
454 return VERR_SSM_UNSUPPORTED_DATA_UNIT_VERSION;
455 }
456
457 pVM->csam.s.savedstate.pSSM = pSSM;
458
459 /*
460 * Restore CSAM structure
461 */
462 rc = SSMR3GetMem(pSSM, &csamInfo, sizeof(csamInfo));
463 AssertRCReturn(rc, rc);
464
465 pVM->csam.s.fGatesChecked = csamInfo.fGatesChecked;
466 pVM->csam.s.fScanningStarted = csamInfo.fScanningStarted;
467
468 /* Restore dirty code page info. */
469 pVM->csam.s.cDirtyPages = csamInfo.cDirtyPages;
470 memcpy(pVM->csam.s.pvDirtyBasePage, csamInfo.pvDirtyBasePage, sizeof(pVM->csam.s.pvDirtyBasePage));
471 memcpy(pVM->csam.s.pvDirtyFaultPage, csamInfo.pvDirtyFaultPage, sizeof(pVM->csam.s.pvDirtyFaultPage));
472
473 /* Restore possible code page */
474 pVM->csam.s.cPossibleCodePages = csamInfo.cPossibleCodePages;
475 memcpy(pVM->csam.s.pvPossibleCodePage, csamInfo.pvPossibleCodePage, sizeof(pVM->csam.s.pvPossibleCodePage));
476
477 /* Restore pgdir bitmap (we'll change the pointers next). */
478 rc = SSMR3GetMem(pSSM, pVM->csam.s.pPDBitmapHC, CSAM_PGDIRBMP_CHUNKS*sizeof(RTHCPTR));
479 AssertRCReturn(rc, rc);
480
481 /*
482 * Restore page bitmaps
483 */
484 for (unsigned i=0;i<CSAM_PGDIRBMP_CHUNKS;i++)
485 {
486 if(pVM->csam.s.pPDBitmapHC[i])
487 {
488 rc = MMHyperAlloc(pVM, CSAM_PAGE_BITMAP_SIZE, 0, MM_TAG_CSAM, (void **)&pVM->csam.s.pPDBitmapHC[i]);
489 if (VBOX_FAILURE(rc))
490 {
491 Log(("MMR3HyperAlloc failed with %d\n", rc));
492 return rc;
493 }
494 /* Convert to GC pointer. */
495 pVM->csam.s.pPDGCBitmapHC[i] = MMHyperHC2GC(pVM, pVM->csam.s.pPDBitmapHC[i]);
496 Assert(pVM->csam.s.pPDGCBitmapHC[i]);
497
498 /* Restore the bitmap. */
499 rc = SSMR3GetMem(pSSM, pVM->csam.s.pPDBitmapHC[i], CSAM_PAGE_BITMAP_SIZE);
500 AssertRCReturn(rc, rc);
501 }
502 else
503 {
504 Assert(!pVM->csam.s.pPDGCBitmapHC[i]);
505 pVM->csam.s.pPDGCBitmapHC[i] = 0;
506 }
507 }
508
509 /*
510 * Restore page records
511 */
512 for (uint32_t i=0;i<csamInfo.savedstate.cPageRecords + csamInfo.savedstate.cPatchPageRecords;i++)
513 {
514 CSAMPAGEREC page;
515 PCSAMPAGE pPage;
516
517 rc = SSMR3GetMem(pSSM, &page, sizeof(page));
518 AssertRCReturn(rc, rc);
519
520 /*
521 * Recreate the page record
522 */
523 pPage = csamCreatePageRecord(pVM, page.page.pPageGC, page.page.enmTag, page.page.fCode32, page.page.fMonitorInvalidation);
524 AssertReturn(pPage, VERR_NO_MEMORY);
525
526 pPage->GCPhys = page.page.GCPhys;
527 pPage->fFlags = page.page.fFlags;
528 pPage->u64Hash = page.page.u64Hash;
529
530 if (page.page.pBitmap)
531 {
532 rc = SSMR3GetMem(pSSM, pPage->pBitmap, CSAM_PAGE_BITMAP_SIZE);
533 AssertRCReturn(rc, rc);
534 }
535 else
536 {
537 MMR3HeapFree(pPage->pBitmap);
538 pPage->pBitmap = 0;
539 }
540 }
541
542 /** @note we don't restore aDangerousInstr; it will be recreated automatically. */
543 memset(&pVM->csam.s.aDangerousInstr, 0, sizeof(pVM->csam.s.aDangerousInstr));
544 pVM->csam.s.cDangerousInstr = 0;
545 pVM->csam.s.iDangerousInstr = 0;
546 return VINF_SUCCESS;
547}
548
549/**
550 * Convert guest context address to host context pointer
551 *
552 * @returns VBox status code.
553 * @param pVM The VM to operate on.
554 * @param pCacheRec Address conversion cache record
555 * @param pGCPtr Guest context pointer
556 *
557 * @returns Host context pointer or NULL in case of an error
558 *
559 */
560static R3PTRTYPE(void *) CSAMGCVirtToHCVirt(PVM pVM, PCSAMP2GLOOKUPREC pCacheRec, RCPTRTYPE(uint8_t *) pGCPtr)
561{
562 int rc;
563 R3PTRTYPE(void *) pHCPtr;
564
565 STAM_PROFILE_START(&pVM->csam.s.StatTimeAddrConv, a);
566
567 pHCPtr = PATMR3GCPtrToHCPtr(pVM, pGCPtr);
568 if (pHCPtr) return pHCPtr;
569
570 if (pCacheRec->pPageLocStartHC)
571 {
572 uint32_t offset = pGCPtr & PAGE_OFFSET_MASK;
573 if (pCacheRec->pGuestLoc == (pGCPtr & PAGE_BASE_GC_MASK))
574 {
575 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeAddrConv, a);
576 return pCacheRec->pPageLocStartHC + offset;
577 }
578 }
579
580 rc = PGMPhysGCPtr2HCPtr(pVM, pGCPtr, &pHCPtr);
581 if (rc != VINF_SUCCESS)
582 {
583//// AssertMsgRC(rc, ("MMR3PhysGCVirt2HCVirtEx failed for %VRv\n", pGCPtr));
584 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeAddrConv, a);
585 return NULL;
586 }
587////invalid? Assert(sizeof(R3PTRTYPE(uint8_t*)) == sizeof(uint32_t));
588
589 pCacheRec->pPageLocStartHC = (R3PTRTYPE(uint8_t*))((RTHCUINTPTR)pHCPtr & PAGE_BASE_HC_MASK);
590 pCacheRec->pGuestLoc = pGCPtr & PAGE_BASE_GC_MASK;
591 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeAddrConv, a);
592 return pHCPtr;
593}
594
595/**
596 * Read callback for disassembly function; supports reading bytes that cross a page boundary
597 *
598 * @returns VBox status code.
599 * @param pSrc GC source pointer
600 * @param pDest HC destination pointer
601 * @param size Number of bytes to read
602 * @param dwUserdata Callback specific user data (pCpu)
603 *
604 */
605static DECLCALLBACK(int) CSAMR3ReadBytes(RTUINTPTR pSrc, uint8_t *pDest, unsigned size, void *pvUserdata)
606{
607 DISCPUSTATE *pCpu = (DISCPUSTATE *)pvUserdata;
608 PVM pVM = (PVM)pCpu->apvUserData[0];
609 RTHCUINTPTR pInstrHC = (RTHCUINTPTR)pCpu->apvUserData[1];
610 RTGCUINTPTR32 pInstrGC = (uintptr_t)pCpu->apvUserData[2];
611 int orgsize = size;
612
613 /* We are not interested in patched instructions, so read the original opcode bytes. */
614 /** @note single instruction patches (int3) are checked in CSAMR3AnalyseCallback */
615 for (int i=0;i<orgsize;i++)
616 {
617 int rc = PATMR3QueryOpcode(pVM, (RTRCPTR)pSrc, pDest);
618 if (VBOX_SUCCESS(rc))
619 {
620 pSrc++;
621 pDest++;
622 size--;
623 }
624 else
625 break;
626 }
627 if (size == 0)
628 return VINF_SUCCESS;
629
630 if (PAGE_ADDRESS(pInstrGC) != PAGE_ADDRESS(pSrc + size - 1) && !PATMIsPatchGCAddr(pVM, pSrc))
631 {
632 return PGMPhysSimpleReadGCPtr(pVM, pDest, pSrc, size);
633 }
634 else
635 {
636 Assert(pInstrHC);
637
638 /* pInstrHC is the base address; adjust according to the GC pointer. */
639 pInstrHC = pInstrHC + (pSrc - pInstrGC);
640
641 memcpy(pDest, (void *)pInstrHC, size);
642 }
643
644 return VINF_SUCCESS;
645}
646
647inline int CSAMR3DISInstr(PVM pVM, DISCPUSTATE *pCpu, RTRCPTR InstrGC, uint8_t *InstrHC, uint32_t *pOpsize, char *pszOutput)
648{
649 (pCpu)->pfnReadBytes = CSAMR3ReadBytes;
650 (pCpu)->apvUserData[0] = pVM;
651 (pCpu)->apvUserData[1] = InstrHC;
652 (pCpu)->apvUserData[2] = (void *)InstrGC; Assert(sizeof(InstrGC) <= sizeof(pCpu->apvUserData[0]));
653#ifdef DEBUG
654 return DISInstrEx(pCpu, InstrGC, 0, pOpsize, pszOutput, OPTYPE_ALL);
655#else
656 /* We are interested in everything except harmless stuff */
657 return DISInstrEx(pCpu, InstrGC, 0, pOpsize, pszOutput, ~(OPTYPE_INVALID | OPTYPE_HARMLESS | OPTYPE_RRM_MASK));
658#endif
659}
660
661/**
662 * Analyses the instructions following the cli for compliance with our heuristics for cli
663 *
664 * @returns VBox status code.
665 * @param pVM The VM to operate on.
666 * @param pCpu CPU disassembly state
667 * @param pInstrGC Guest context pointer to privileged instruction
668 * @param pCurInstrGC Guest context pointer to the current instruction
669 * @param pCacheRec GC to HC cache record
670 * @param pUserData User pointer (callback specific)
671 *
672 */
673static int CSAMR3AnalyseCallback(PVM pVM, DISCPUSTATE *pCpu, RCPTRTYPE(uint8_t *) pInstrGC, RCPTRTYPE(uint8_t *) pCurInstrGC,
674 PCSAMP2GLOOKUPREC pCacheRec, void *pUserData)
675{
676 PCSAMPAGE pPage = (PCSAMPAGE)pUserData;
677 int rc;
678
679 switch(pCpu->pCurInstr->opcode)
680 {
681 case OP_INT:
682 Assert(pCpu->param1.flags & USE_IMMEDIATE8);
683 if (pCpu->param1.parval == 3)
684 {
685 //two byte int 3
686 return VINF_SUCCESS;
687 }
688 break;
689
690 case OP_ILLUD2:
691 /* This appears to be some kind of kernel panic in Linux 2.4; no point to continue. */
692 case OP_RETN:
693 case OP_INT3:
694 case OP_INVALID:
695#if 1
696 /* removing breaks win2k guests? */
697 case OP_IRET:
698#endif
699 return VINF_SUCCESS;
700 }
701
702 // Check for exit points
703 switch (pCpu->pCurInstr->opcode)
704 {
705 /* It's not a good idea to patch pushf instructions:
706 * - increases the chance of conflicts (code jumping to the next instruction)
707 * - better to patch the cli
708 * - code that branches before the cli will likely hit an int 3
709 * - in general doesn't offer any benefits as we don't allow nested patch blocks (IF is always 1)
710 */
711 case OP_PUSHF:
712 case OP_POPF:
713 break;
714
715 case OP_CLI:
716 {
717 uint32_t cbInstr = 0;
718 uint32_t opsize = pCpu->opsize;
719
720 PATMR3AddHint(pVM, pCurInstrGC, (pPage->fCode32) ? PATMFL_CODE32 : 0);
721
722 /* Make sure the instructions that follow the cli have not been encountered before. */
723 while (true)
724 {
725 DISCPUSTATE cpu;
726 uint8_t *pCurInstrHC = 0;
727
728 if (cbInstr + opsize >= SIZEOF_NEARJUMP32)
729 break;
730
731 if (csamIsCodeScanned(pVM, pCurInstrGC + opsize, &pPage) == true)
732 {
733 /* We've scanned the next instruction(s) already. This means we've followed a branch that ended up there before -> dangerous!! */
734 PATMR3DetectConflict(pVM, pCurInstrGC, pCurInstrGC + opsize);
735 break;
736 }
737 pCurInstrGC += opsize;
738 cbInstr += opsize;
739
740 pCurInstrHC = (uint8_t *)CSAMGCVirtToHCVirt(pVM, pCacheRec, pCurInstrGC);
741 if (pCurInstrHC == NULL)
742 {
743 Log(("CSAMGCVirtToHCVirt failed for %VRv\n", pCurInstrGC));
744 break;
745 }
746 Assert(VALID_PTR(pCurInstrHC));
747
748 cpu.mode = (pPage->fCode32) ? CPUMODE_32BIT : CPUMODE_16BIT;
749 rc = CSAMR3DISInstr(pVM, &cpu, pCurInstrGC, pCurInstrHC, &opsize, NULL);
750 Assert(VBOX_SUCCESS(rc));
751 if (VBOX_FAILURE(rc))
752 break;
753 }
754 break;
755 }
756
757 case OP_PUSH:
758 if (pCpu->pCurInstr->param1 != OP_PARM_REG_CS)
759 break;
760
761 /* no break */
762 case OP_STR:
763 case OP_LSL:
764 case OP_LAR:
765 case OP_SGDT:
766 case OP_SLDT:
767 case OP_SIDT:
768 case OP_SMSW:
769 case OP_VERW:
770 case OP_VERR:
771 case OP_CPUID:
772 case OP_IRET:
773#ifdef DEBUG
774 switch(pCpu->pCurInstr->opcode)
775 {
776 case OP_STR:
777 Log(("Privileged instruction at %VRv: str!!\n", pCurInstrGC));
778 break;
779 case OP_LSL:
780 Log(("Privileged instruction at %VRv: lsl!!\n", pCurInstrGC));
781 break;
782 case OP_LAR:
783 Log(("Privileged instruction at %VRv: lar!!\n", pCurInstrGC));
784 break;
785 case OP_SGDT:
786 Log(("Privileged instruction at %VRv: sgdt!!\n", pCurInstrGC));
787 break;
788 case OP_SLDT:
789 Log(("Privileged instruction at %VRv: sldt!!\n", pCurInstrGC));
790 break;
791 case OP_SIDT:
792 Log(("Privileged instruction at %VRv: sidt!!\n", pCurInstrGC));
793 break;
794 case OP_SMSW:
795 Log(("Privileged instruction at %VRv: smsw!!\n", pCurInstrGC));
796 break;
797 case OP_VERW:
798 Log(("Privileged instruction at %VRv: verw!!\n", pCurInstrGC));
799 break;
800 case OP_VERR:
801 Log(("Privileged instruction at %VRv: verr!!\n", pCurInstrGC));
802 break;
803 case OP_CPUID:
804 Log(("Privileged instruction at %VRv: cpuid!!\n", pCurInstrGC));
805 break;
806 case OP_PUSH:
807 Log(("Privileged instruction at %VRv: push cs!!\n", pCurInstrGC));
808 break;
809 case OP_IRET:
810 Log(("Privileged instruction at %VRv: iret!!\n", pCurInstrGC));
811 break;
812 }
813#endif
814
815 if (PATMR3HasBeenPatched(pVM, pCurInstrGC) == false)
816 {
817 rc = PATMR3InstallPatch(pVM, pCurInstrGC, (pPage->fCode32) ? PATMFL_CODE32 : 0);
818 if (VBOX_FAILURE(rc))
819 {
820 Log(("PATMR3InstallPatch failed with %d\n", rc));
821 return VWRN_CONTINUE_ANALYSIS;
822 }
823 }
824 if (pCpu->pCurInstr->opcode == OP_IRET)
825 return VINF_SUCCESS; /* Look no further in this branch. */
826
827 return VWRN_CONTINUE_ANALYSIS;
828
829 case OP_JMP:
830 case OP_CALL:
831 {
832 // return or jump/call through a jump table
833 if (OP_PARM_VTYPE(pCpu->pCurInstr->param1) != OP_PARM_J)
834 {
835#ifdef DEBUG
836 switch(pCpu->pCurInstr->opcode)
837 {
838 case OP_JMP:
839 Log(("Control Flow instruction at %VRv: jmp!!\n", pCurInstrGC));
840 break;
841 case OP_CALL:
842 Log(("Control Flow instruction at %VRv: call!!\n", pCurInstrGC));
843 break;
844 }
845#endif
846 return VWRN_CONTINUE_ANALYSIS;
847 }
848 return VWRN_CONTINUE_ANALYSIS;
849 }
850
851 }
852
853 return VWRN_CONTINUE_ANALYSIS;
854}
855
856#ifdef CSAM_ANALYSE_BEYOND_RET
857/**
858 * Wrapper for csamAnalyseCodeStream for call instructions.
859 *
860 * @returns VBox status code.
861 * @param pVM The VM to operate on.
862 * @param pInstrGC Guest context pointer to privileged instruction
863 * @param pCurInstrGC Guest context pointer to the current instruction
864 * @param fCode32 16 or 32 bits code
865 * @param pfnCSAMR3Analyse Callback for testing the disassembled instruction
866 * @param pUserData User pointer (callback specific)
867 *
868 */
869static int csamAnalyseCallCodeStream(PVM pVM, RCPTRTYPE(uint8_t *) pInstrGC, RCPTRTYPE(uint8_t *) pCurInstrGC, bool fCode32,
870 PFN_CSAMR3ANALYSE pfnCSAMR3Analyse, void *pUserData, PCSAMP2GLOOKUPREC pCacheRec)
871{
872 int rc;
873 CSAMCALLEXITREC CallExitRec;
874 PCSAMCALLEXITREC pOldCallRec;
875 PCSAMPAGE pPage = 0;
876 uint32_t i;
877
878 CallExitRec.cInstrAfterRet = 0;
879
880 pOldCallRec = pCacheRec->pCallExitRec;
881 pCacheRec->pCallExitRec = &CallExitRec;
882
883 rc = csamAnalyseCodeStream(pVM, pInstrGC, pCurInstrGC, fCode32, pfnCSAMR3Analyse, pUserData, pCacheRec);
884
885 for (i=0;i<CallExitRec.cInstrAfterRet;i++)
886 {
887 PCSAMPAGE pPage = 0;
888
889 pCurInstrGC = CallExitRec.pInstrAfterRetGC[i];
890
891 /* Check if we've previously encountered the instruction after the ret. */
892 if (csamIsCodeScanned(pVM, pCurInstrGC, &pPage) == false)
893 {
894 DISCPUSTATE cpu;
895 uint32_t opsize;
896 uint8_t *pCurInstrHC = 0;
897 int rc2;
898#ifdef DEBUG
899 char szOutput[256];
900#endif
901 if (pPage == NULL)
902 {
903 /* New address; let's take a look at it. */
904 pPage = csamCreatePageRecord(pVM, pCurInstrGC, CSAM_TAG_CSAM, fCode32);
905 if (pPage == NULL)
906 {
907 rc = VERR_NO_MEMORY;
908 goto done;
909 }
910 }
911
912 /**
913 * Some generic requirements for recognizing an adjacent function:
914 * - alignment fillers that consist of:
915 * - nop
916 * - lea genregX, [genregX (+ 0)]
917 * - push ebp after the filler (can extend this later); aligned at at least a 4 byte boundary
918 */
919 for (int j=0;j<16;j++)
920 {
921 pCurInstrHC = (uint8_t *)CSAMGCVirtToHCVirt(pVM, pCacheRec, pCurInstrGC);
922 if (pCurInstrHC == NULL)
923 {
924 Log(("CSAMGCVirtToHCVirt failed for %VRv\n", pCurInstrGC));
925 goto done;
926 }
927 Assert(VALID_PTR(pCurInstrHC));
928
929 cpu.mode = (fCode32) ? CPUMODE_32BIT : CPUMODE_16BIT;
930 STAM_PROFILE_START(&pVM->csam.s.StatTimeDisasm, a);
931#ifdef DEBUG
932 rc2 = CSAMR3DISInstr(pVM, &cpu, pCurInstrGC, pCurInstrHC, &opsize, szOutput);
933 if (VBOX_SUCCESS(rc2)) Log(("CSAM Call Analysis: %s", szOutput));
934#else
935 rc2 = CSAMR3DISInstr(pVM, &cpu, pCurInstrGC, pCurInstrHC, &opsize, NULL);
936#endif
937 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeDisasm, a);
938 if (VBOX_FAILURE(rc2))
939 {
940 Log(("Disassembly failed at %VRv with %Vrc (probably page not present) -> return to caller\n", pCurInstrGC, rc2));
941 goto done;
942 }
943
944 STAM_COUNTER_ADD(&pVM->csam.s.StatNrBytesRead, opsize);
945
946 RCPTRTYPE(uint8_t *) addr = 0;
947 PCSAMPAGE pJmpPage = NULL;
948
949 if (PAGE_ADDRESS(pCurInstrGC) != PAGE_ADDRESS(pCurInstrGC + opsize - 1))
950 {
951 if (!PGMGstIsPagePresent(pVM, pCurInstrGC + opsize - 1))
952 {
953 /// @todo fault in the page
954 Log(("Page for current instruction %VRv is not present!!\n", pCurInstrGC));
955 goto done;
956 }
957 //all is fine, let's continue
958 csamR3CheckPageRecord(pVM, pCurInstrGC + opsize - 1);
959 }
960
961 switch (cpu.pCurInstr->opcode)
962 {
963 case OP_NOP:
964 case OP_INT3:
965 break; /* acceptable */
966
967 case OP_LEA:
968 /* Must be similar to:
969 *
970 * lea esi, [esi]
971 * lea esi, [esi+0]
972 * Any register is allowed as long as source and destination are identical.
973 */
974 if ( cpu.param1.flags != USE_REG_GEN32
975 || ( cpu.param2.flags != USE_REG_GEN32
976 && ( !(cpu.param2.flags & USE_REG_GEN32)
977 || !(cpu.param2.flags & (USE_DISPLACEMENT8|USE_DISPLACEMENT16|USE_DISPLACEMENT32))
978 || cpu.param2.parval != 0
979 )
980 )
981 || cpu.param1.base.reg_gen32 != cpu.param2.base.reg_gen32
982 )
983 {
984 STAM_COUNTER_INC(&pVM->csam.s.StatScanNextFunctionFailed);
985 goto next_function;
986 }
987 break;
988
989 case OP_PUSH:
990 {
991 if ( (pCurInstrGC & 0x3) != 0
992 || cpu.param1.flags != USE_REG_GEN32
993 || cpu.param1.base.reg_gen32 != USE_REG_EBP
994 )
995 {
996 STAM_COUNTER_INC(&pVM->csam.s.StatScanNextFunctionFailed);
997 goto next_function;
998 }
999
1000 if (csamIsCodeScanned(pVM, pCurInstrGC, &pPage) == false)
1001 {
1002 CSAMCALLEXITREC CallExitRec2;
1003 CallExitRec2.cInstrAfterRet = 0;
1004
1005 pCacheRec->pCallExitRec = &CallExitRec2;
1006
1007 /* Analyse the function. */
1008 Log(("Found new function at %VRv\n", pCurInstrGC));
1009 STAM_COUNTER_INC(&pVM->csam.s.StatScanNextFunction);
1010 csamAnalyseCallCodeStream(pVM, pInstrGC, pCurInstrGC, fCode32, pfnCSAMR3Analyse, pUserData, pCacheRec);
1011 }
1012 goto next_function;
1013 }
1014
1015 case OP_SUB:
1016 {
1017 if ( (pCurInstrGC & 0x3) != 0
1018 || cpu.param1.flags != USE_REG_GEN32
1019 || cpu.param1.base.reg_gen32 != USE_REG_ESP
1020 )
1021 {
1022 STAM_COUNTER_INC(&pVM->csam.s.StatScanNextFunctionFailed);
1023 goto next_function;
1024 }
1025
1026 if (csamIsCodeScanned(pVM, pCurInstrGC, &pPage) == false)
1027 {
1028 CSAMCALLEXITREC CallExitRec2;
1029 CallExitRec2.cInstrAfterRet = 0;
1030
1031 pCacheRec->pCallExitRec = &CallExitRec2;
1032
1033 /* Analyse the function. */
1034 Log(("Found new function at %VRv\n", pCurInstrGC));
1035 STAM_COUNTER_INC(&pVM->csam.s.StatScanNextFunction);
1036 csamAnalyseCallCodeStream(pVM, pInstrGC, pCurInstrGC, fCode32, pfnCSAMR3Analyse, pUserData, pCacheRec);
1037 }
1038 goto next_function;
1039 }
1040
1041 default:
1042 STAM_COUNTER_INC(&pVM->csam.s.StatScanNextFunctionFailed);
1043 goto next_function;
1044 }
1045 /* Mark it as scanned. */
1046 csamMarkCode(pVM, pPage, pCurInstrGC, opsize, true);
1047 pCurInstrGC += opsize;
1048 } /* for at most 16 instructions */
1049next_function:
1050 ; /* MSVC complains otherwise */
1051 }
1052 }
1053done:
1054 pCacheRec->pCallExitRec = pOldCallRec;
1055 return rc;
1056}
1057#else
1058#define csamAnalyseCallCodeStream csamAnalyseCodeStream
1059#endif
1060
1061/**
1062 * Disassembles the code stream until the callback function detects a failure or decides everything is acceptable
1063 *
1064 * @returns VBox status code.
1065 * @param pVM The VM to operate on.
1066 * @param pInstrGC Guest context pointer to privileged instruction
1067 * @param pCurInstrGC Guest context pointer to the current instruction
1068 * @param fCode32 16 or 32 bits code
1069 * @param pfnCSAMR3Analyse Callback for testing the disassembled instruction
1070 * @param pUserData User pointer (callback specific)
1071 *
1072 */
1073static int csamAnalyseCodeStream(PVM pVM, RCPTRTYPE(uint8_t *) pInstrGC, RCPTRTYPE(uint8_t *) pCurInstrGC, bool fCode32,
1074 PFN_CSAMR3ANALYSE pfnCSAMR3Analyse, void *pUserData, PCSAMP2GLOOKUPREC pCacheRec)
1075{
1076 DISCPUSTATE cpu;
1077 PCSAMPAGE pPage = (PCSAMPAGE)pUserData;
1078 int rc = VWRN_CONTINUE_ANALYSIS;
1079 uint32_t opsize;
1080 R3PTRTYPE(uint8_t *) pCurInstrHC = 0;
1081 int rc2;
1082
1083#ifdef DEBUG
1084 char szOutput[256];
1085#endif
1086
1087 LogFlow(("csamAnalyseCodeStream: code at %VRv depth=%d\n", pCurInstrGC, pCacheRec->depth));
1088
1089 pVM->csam.s.fScanningStarted = true;
1090
1091 pCacheRec->depth++;
1092 /*
1093 * Limit the call depth. (rather arbitrary upper limit; too low and we won't detect certain
1094 * cpuid instructions in Linux kernels; too high and we waste too much time scanning code)
1095 * (512 is necessary to detect cpuid instructions in Red Hat EL4; see defect 1355)
1096 * @note we are using a lot of stack here. couple of 100k when we go to the full depth (!)
1097 */
1098 if (pCacheRec->depth > 512)
1099 {
1100 LogFlow(("CSAM: maximum calldepth reached for %VRv\n", pCurInstrGC));
1101 pCacheRec->depth--;
1102 return VINF_SUCCESS; //let's not go on forever
1103 }
1104
1105 Assert(!PATMIsPatchGCAddr(pVM, pCurInstrGC));
1106 csamR3CheckPageRecord(pVM, pCurInstrGC);
1107
1108 while(rc == VWRN_CONTINUE_ANALYSIS)
1109 {
1110 if (csamIsCodeScanned(pVM, pCurInstrGC, &pPage) == false)
1111 {
1112 if (pPage == NULL)
1113 {
1114 /* New address; let's take a look at it. */
1115 pPage = csamCreatePageRecord(pVM, pCurInstrGC, CSAM_TAG_CSAM, fCode32);
1116 if (pPage == NULL)
1117 {
1118 rc = VERR_NO_MEMORY;
1119 goto done;
1120 }
1121 }
1122 }
1123 else
1124 {
1125 LogFlow(("Code at %VRv has been scanned before\n", pCurInstrGC));
1126 rc = VINF_SUCCESS;
1127 goto done;
1128 }
1129
1130 pCurInstrHC = (uint8_t *)CSAMGCVirtToHCVirt(pVM, pCacheRec, pCurInstrGC);
1131 if (pCurInstrHC == NULL)
1132 {
1133 Log(("CSAMGCVirtToHCVirt failed for %VRv\n", pCurInstrGC));
1134 rc = VERR_PATCHING_REFUSED;
1135 goto done;
1136 }
1137 Assert(VALID_PTR(pCurInstrHC));
1138
1139 cpu.mode = (fCode32) ? CPUMODE_32BIT : CPUMODE_16BIT;
1140 STAM_PROFILE_START(&pVM->csam.s.StatTimeDisasm, a);
1141#ifdef DEBUG
1142 rc2 = CSAMR3DISInstr(pVM, &cpu, pCurInstrGC, pCurInstrHC, &opsize, szOutput);
1143 if (VBOX_SUCCESS(rc2)) Log(("CSAM Analysis: %s", szOutput));
1144#else
1145 rc2 = CSAMR3DISInstr(pVM, &cpu, pCurInstrGC, pCurInstrHC, &opsize, NULL);
1146#endif
1147 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeDisasm, a);
1148 if (VBOX_FAILURE(rc2))
1149 {
1150 Log(("Disassembly failed at %VRv with %Vrc (probably page not present) -> return to caller\n", pCurInstrGC, rc2));
1151 rc = VINF_SUCCESS;
1152 goto done;
1153 }
1154
1155 STAM_COUNTER_ADD(&pVM->csam.s.StatNrBytesRead, opsize);
1156
1157 csamMarkCode(pVM, pPage, pCurInstrGC, opsize, true);
1158
1159 RCPTRTYPE(uint8_t *) addr = 0;
1160 PCSAMPAGE pJmpPage = NULL;
1161
1162 if (PAGE_ADDRESS(pCurInstrGC) != PAGE_ADDRESS(pCurInstrGC + opsize - 1))
1163 {
1164 if (!PGMGstIsPagePresent(pVM, pCurInstrGC + opsize - 1))
1165 {
1166 /// @todo fault in the page
1167 Log(("Page for current instruction %VRv is not present!!\n", pCurInstrGC));
1168 rc = VWRN_CONTINUE_ANALYSIS;
1169 goto next_please;
1170 }
1171 //all is fine, let's continue
1172 csamR3CheckPageRecord(pVM, pCurInstrGC + opsize - 1);
1173 }
1174 /*
1175 * If it's harmless, then don't bother checking it (the disasm tables had better be accurate!)
1176 */
1177 if ((cpu.pCurInstr->optype & ~OPTYPE_RRM_MASK) == OPTYPE_HARMLESS)
1178 {
1179 AssertMsg(pfnCSAMR3Analyse(pVM, &cpu, pInstrGC, pCurInstrGC, pCacheRec, (void *)pPage) == VWRN_CONTINUE_ANALYSIS, ("Instruction incorrectly marked harmless?!?!?\n"));
1180 rc = VWRN_CONTINUE_ANALYSIS;
1181 goto next_please;
1182 }
1183
1184#ifdef CSAM_ANALYSE_BEYOND_RET
1185 /* Remember the address of the instruction following the ret in case the parent instruction was a call. */
1186 if ( pCacheRec->pCallExitRec
1187 && cpu.pCurInstr->opcode == OP_RETN
1188 && pCacheRec->pCallExitRec->cInstrAfterRet < CSAM_MAX_CALLEXIT_RET)
1189 {
1190 pCacheRec->pCallExitRec->pInstrAfterRetGC[pCacheRec->pCallExitRec->cInstrAfterRet] = pCurInstrGC + opsize;
1191 pCacheRec->pCallExitRec->cInstrAfterRet++;
1192 }
1193#endif
1194
1195 rc = pfnCSAMR3Analyse(pVM, &cpu, pInstrGC, pCurInstrGC, pCacheRec, (void *)pPage);
1196 if (rc == VINF_SUCCESS)
1197 goto done;
1198
1199 // For our first attempt, we'll handle only simple relative jumps and calls (immediate offset coded in instruction)
1200 if ( ((cpu.pCurInstr->optype & OPTYPE_CONTROLFLOW) && (OP_PARM_VTYPE(cpu.pCurInstr->param1) == OP_PARM_J))
1201 || (cpu.pCurInstr->opcode == OP_CALL && cpu.param1.flags == USE_DISPLACEMENT32)) /* simple indirect call (call dword ptr [address]) */
1202 {
1203 /* We need to parse 'call dword ptr [address]' type of calls to catch cpuid instructions in some recent Linux distributions (e.g. OpenSuse 10.3) */
1204 if ( cpu.pCurInstr->opcode == OP_CALL
1205 && cpu.param1.flags == USE_DISPLACEMENT32)
1206 {
1207 addr = 0;
1208 PGMPhysSimpleReadGCPtr(pVM, &addr, (RTRCUINTPTR)cpu.param1.disp32, sizeof(addr));
1209 }
1210 else
1211 addr = CSAMResolveBranch(&cpu, pCurInstrGC);
1212
1213 if (addr == 0)
1214 {
1215 Log(("We don't support far jumps here!! (%08X)\n", cpu.param1.flags));
1216 rc = VINF_SUCCESS;
1217 break;
1218 }
1219 Assert(!PATMIsPatchGCAddr(pVM, addr));
1220
1221 /* If the target address lies in a patch generated jump, then special action needs to be taken. */
1222 PATMR3DetectConflict(pVM, pCurInstrGC, addr);
1223
1224 /* Same page? */
1225 if (PAGE_ADDRESS(addr) != PAGE_ADDRESS(pCurInstrGC ))
1226 {
1227 if (!PGMGstIsPagePresent(pVM, addr))
1228 {
1229 Log(("Page for current instruction %VRv is not present!!\n", addr));
1230 rc = VWRN_CONTINUE_ANALYSIS;
1231 goto next_please;
1232 }
1233
1234 /* All is fine, let's continue. */
1235 csamR3CheckPageRecord(pVM, addr);
1236 }
1237
1238 pJmpPage = NULL;
1239 if (csamIsCodeScanned(pVM, addr, &pJmpPage) == false)
1240 {
1241 if (pJmpPage == NULL)
1242 {
1243 /* New branch target; let's take a look at it. */
1244 pJmpPage = csamCreatePageRecord(pVM, addr, CSAM_TAG_CSAM, fCode32);
1245 if (pJmpPage == NULL)
1246 {
1247 rc = VERR_NO_MEMORY;
1248 goto done;
1249 }
1250 Assert(pPage);
1251 }
1252 if (cpu.pCurInstr->opcode == OP_CALL)
1253 rc = csamAnalyseCallCodeStream(pVM, pInstrGC, addr, fCode32, pfnCSAMR3Analyse, (void *)pJmpPage, pCacheRec);
1254 else
1255 rc = csamAnalyseCodeStream(pVM, pInstrGC, addr, fCode32, pfnCSAMR3Analyse, (void *)pJmpPage, pCacheRec);
1256
1257 if (rc != VINF_SUCCESS) {
1258 goto done;
1259 }
1260 }
1261 if (cpu.pCurInstr->opcode == OP_JMP)
1262 {//unconditional jump; return to caller
1263 rc = VINF_SUCCESS;
1264 goto done;
1265 }
1266
1267 rc = VWRN_CONTINUE_ANALYSIS;
1268 } //if ((cpu.pCurInstr->optype & OPTYPE_CONTROLFLOW) && (OP_PARM_VTYPE(cpu.pCurInstr->param1) == OP_PARM_J))
1269#ifdef CSAM_SCAN_JUMP_TABLE
1270 else
1271 if ( cpu.pCurInstr->opcode == OP_JMP
1272 && (cpu.param1.flags & (USE_DISPLACEMENT32|USE_INDEX|USE_SCALE)) == (USE_DISPLACEMENT32|USE_INDEX|USE_SCALE)
1273 )
1274 {
1275 RTRCPTR pJumpTableGC = (RTRCPTR)cpu.param1.disp32;
1276 uint8_t *pJumpTableHC;
1277 int rc2;
1278
1279 Log(("Jump through jump table\n"));
1280
1281 rc2 = PGMPhysGCPtr2HCPtr(pVM, pJumpTableGC, (PRTHCPTR)&pJumpTableHC);
1282 if (rc2 == VINF_SUCCESS)
1283 {
1284 for (uint32_t i=0;i<2;i++)
1285 {
1286 uint64_t fFlags;
1287
1288 addr = pJumpTableGC + cpu.param1.scale * i;
1289 /* Same page? */
1290 if (PAGE_ADDRESS(addr) != PAGE_ADDRESS(pJumpTableGC))
1291 break;
1292
1293 addr = *(RTRCPTR *)(pJumpTableHC + cpu.param1.scale * i);
1294
1295 rc2 = PGMGstGetPage(pVM, addr, &fFlags, NULL);
1296 if ( rc2 != VINF_SUCCESS
1297 || (fFlags & X86_PTE_US)
1298 || !(fFlags & X86_PTE_P)
1299 )
1300 break;
1301
1302 Log(("Jump to %VRv\n", addr));
1303
1304 pJmpPage = NULL;
1305 if (csamIsCodeScanned(pVM, addr, &pJmpPage) == false)
1306 {
1307 if (pJmpPage == NULL)
1308 {
1309 /* New branch target; let's take a look at it. */
1310 pJmpPage = csamCreatePageRecord(pVM, addr, CSAM_TAG_CSAM, fCode32);
1311 if (pJmpPage == NULL)
1312 {
1313 rc = VERR_NO_MEMORY;
1314 goto done;
1315 }
1316 Assert(pPage);
1317 }
1318 rc = csamAnalyseCodeStream(pVM, pInstrGC, addr, fCode32, pfnCSAMR3Analyse, (void *)pJmpPage, pCacheRec);
1319 if (rc != VINF_SUCCESS) {
1320 goto done;
1321 }
1322 }
1323 }
1324 }
1325 }
1326#endif
1327 if (rc != VWRN_CONTINUE_ANALYSIS) {
1328 break; //done!
1329 }
1330next_please:
1331 if (cpu.pCurInstr->opcode == OP_JMP)
1332 {
1333 rc = VINF_SUCCESS;
1334 goto done;
1335 }
1336 pCurInstrGC += opsize;
1337 }
1338done:
1339 pCacheRec->depth--;
1340 return rc;
1341}
1342
1343
1344/**
1345 * Calculates the 64 bits hash value for the current page
1346 *
1347 * @returns hash value
1348 * @param pVM The VM to operate on.
1349 * @param pInstr Page address
1350 */
1351uint64_t csamR3CalcPageHash(PVM pVM, RTRCPTR pInstr)
1352{
1353 uint64_t hash = 0;
1354 uint32_t val[5];
1355 int rc;
1356
1357 Assert((pInstr & PAGE_OFFSET_MASK) == 0);
1358
1359 rc = PGMPhysSimpleReadGCPtr(pVM, &val[0], pInstr, sizeof(val[0]));
1360 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
1361 if (rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT)
1362 {
1363 Log(("csamR3CalcPageHash: page %VRv not present!!\n", pInstr));
1364 return ~0ULL;
1365 }
1366
1367 rc = PGMPhysSimpleReadGCPtr(pVM, &val[1], pInstr+1024, sizeof(val[0]));
1368 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
1369 if (rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT)
1370 {
1371 Log(("csamR3CalcPageHash: page %VRv not present!!\n", pInstr));
1372 return ~0ULL;
1373 }
1374
1375 rc = PGMPhysSimpleReadGCPtr(pVM, &val[2], pInstr+2048, sizeof(val[0]));
1376 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
1377 if (rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT)
1378 {
1379 Log(("csamR3CalcPageHash: page %VRv not present!!\n", pInstr));
1380 return ~0ULL;
1381 }
1382
1383 rc = PGMPhysSimpleReadGCPtr(pVM, &val[3], pInstr+3072, sizeof(val[0]));
1384 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
1385 if (rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT)
1386 {
1387 Log(("csamR3CalcPageHash: page %VRv not present!!\n", pInstr));
1388 return ~0ULL;
1389 }
1390
1391 rc = PGMPhysSimpleReadGCPtr(pVM, &val[4], pInstr+4092, sizeof(val[0]));
1392 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
1393 if (rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT)
1394 {
1395 Log(("csamR3CalcPageHash: page %VRv not present!!\n", pInstr));
1396 return ~0ULL;
1397 }
1398
1399 // don't want to get division by zero traps
1400 val[2] |= 1;
1401 val[4] |= 1;
1402
1403 hash = (uint64_t)val[0] * (uint64_t)val[1] / (uint64_t)val[2] + (val[3]%val[4]);
1404 return (hash == ~0ULL) ? hash - 1 : hash;
1405}
1406
1407
1408/**
1409 * Notify CSAM of a page flush
1410 *
1411 * @returns VBox status code
1412 * @param pVM The VM to operate on.
1413 * @param addr GC address of the page to flush
1414 * @param fRemovePage Page removal flag
1415 */
1416static int csamFlushPage(PVM pVM, RTRCPTR addr, bool fRemovePage)
1417{
1418 PCSAMPAGEREC pPageRec;
1419 int rc;
1420 RTGCPHYS GCPhys = 0;
1421 uint64_t fFlags = 0;
1422
1423 if (!CSAMIsEnabled(pVM))
1424 return VINF_SUCCESS;
1425
1426 STAM_PROFILE_START(&pVM->csam.s.StatTimeFlushPage, a);
1427
1428 addr = addr & PAGE_BASE_GC_MASK;
1429
1430 /*
1431 * Note: searching for the page in our tree first is more expensive (skipped flushes are two orders of magnitude more common)
1432 */
1433 if (pVM->csam.s.pPageTree == NULL)
1434 {
1435 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeFlushPage, a);
1436 return VWRN_CSAM_PAGE_NOT_FOUND;
1437 }
1438
1439 rc = PGMGstGetPage(pVM, addr, &fFlags, &GCPhys);
1440 /* Returned at a very early stage (no paging yet presumably). */
1441 if (rc == VERR_NOT_SUPPORTED)
1442 {
1443 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeFlushPage, a);
1444 return rc;
1445 }
1446
1447 if (VBOX_SUCCESS(rc))
1448 {
1449 if ( (fFlags & X86_PTE_US)
1450 || rc == VERR_PGM_PHYS_PAGE_RESERVED
1451 )
1452 {
1453 /* User page -> not relevant for us. */
1454 STAM_COUNTER_ADD(&pVM->csam.s.StatNrFlushesSkipped, 1);
1455 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeFlushPage, a);
1456 return VINF_SUCCESS;
1457 }
1458 }
1459 else
1460 if (rc != VERR_PAGE_NOT_PRESENT && rc != VERR_PAGE_TABLE_NOT_PRESENT)
1461 AssertMsgFailed(("PGMR3GetPage %VRv failed with %Vrc\n", addr, rc));
1462
1463 pPageRec = (PCSAMPAGEREC)RTAvlPVGet(&pVM->csam.s.pPageTree, (AVLPVKEY)addr);
1464 if (pPageRec)
1465 {
1466 if ( GCPhys == pPageRec->page.GCPhys
1467 && (fFlags & X86_PTE_P))
1468 {
1469 STAM_COUNTER_ADD(&pVM->csam.s.StatNrFlushesSkipped, 1);
1470 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeFlushPage, a);
1471 return VINF_SUCCESS;
1472 }
1473
1474 Log(("CSAMR3FlushPage: page %VRv has changed -> FLUSH (rc=%Vrc) (Phys: %VGp vs %VGp)\n", addr, rc, GCPhys, pPageRec->page.GCPhys));
1475
1476 STAM_COUNTER_ADD(&pVM->csam.s.StatNrFlushes, 1);
1477
1478 if (fRemovePage)
1479 csamRemovePageRecord(pVM, addr);
1480 else
1481 {
1482 CSAMMarkPage(pVM, addr, false);
1483 pPageRec->page.GCPhys = 0;
1484 pPageRec->page.fFlags = 0;
1485 rc = PGMGstGetPage(pVM, addr, &pPageRec->page.fFlags, &pPageRec->page.GCPhys);
1486 if (rc == VINF_SUCCESS)
1487 pPageRec->page.u64Hash = csamR3CalcPageHash(pVM, addr);
1488
1489 if (pPageRec->page.pBitmap == NULL)
1490 {
1491 pPageRec->page.pBitmap = (uint8_t *)MMR3HeapAllocZ(pVM, MM_TAG_CSAM_PATCH, CSAM_PAGE_BITMAP_SIZE);
1492 Assert(pPageRec->page.pBitmap);
1493 if (pPageRec->page.pBitmap == NULL)
1494 return VERR_NO_MEMORY;
1495 }
1496 else
1497 memset(pPageRec->page.pBitmap, 0, CSAM_PAGE_BITMAP_SIZE);
1498 }
1499
1500
1501 /*
1502 * Inform patch manager about the flush; no need to repeat the above check twice.
1503 */
1504 PATMR3FlushPage(pVM, addr);
1505
1506 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeFlushPage, a);
1507 return VINF_SUCCESS;
1508 }
1509 else
1510 {
1511 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeFlushPage, a);
1512 return VWRN_CSAM_PAGE_NOT_FOUND;
1513 }
1514}
1515
1516/**
1517 * Notify CSAM of a page flush
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 */
1523VMMR3DECL(int) CSAMR3FlushPage(PVM pVM, RTRCPTR addr)
1524{
1525 return csamFlushPage(pVM, addr, true /* remove page record */);
1526}
1527
1528/**
1529 * Remove a CSAM monitored page. Use with care!
1530 *
1531 * @returns VBox status code
1532 * @param pVM The VM to operate on.
1533 * @param addr GC address of the page to flush
1534 */
1535VMMR3DECL(int) CSAMR3RemovePage(PVM pVM, RTRCPTR addr)
1536{
1537 PCSAMPAGEREC pPageRec;
1538 int rc;
1539
1540 addr = addr & PAGE_BASE_GC_MASK;
1541
1542 pPageRec = (PCSAMPAGEREC)RTAvlPVGet(&pVM->csam.s.pPageTree, (AVLPVKEY)addr);
1543 if (pPageRec)
1544 {
1545 rc = csamRemovePageRecord(pVM, addr);
1546 if (VBOX_SUCCESS(rc))
1547 PATMR3FlushPage(pVM, addr);
1548 return VINF_SUCCESS;
1549 }
1550 return VWRN_CSAM_PAGE_NOT_FOUND;
1551}
1552
1553/**
1554 * Check a page record in case a page has been changed
1555 *
1556 * @returns VBox status code. (trap handled or not)
1557 * @param pVM The VM to operate on.
1558 * @param pInstrGC GC instruction pointer
1559 */
1560int csamR3CheckPageRecord(PVM pVM, RTRCPTR pInstrGC)
1561{
1562 PCSAMPAGEREC pPageRec;
1563 uint64_t u64hash;
1564
1565 pInstrGC = pInstrGC & PAGE_BASE_GC_MASK;
1566
1567 pPageRec = (PCSAMPAGEREC)RTAvlPVGet(&pVM->csam.s.pPageTree, (AVLPVKEY)pInstrGC);
1568 if (pPageRec)
1569 {
1570 u64hash = csamR3CalcPageHash(pVM, pInstrGC);
1571 if (u64hash != pPageRec->page.u64Hash)
1572 csamFlushPage(pVM, pInstrGC, false /* don't remove page record */);
1573 }
1574 else
1575 return VWRN_CSAM_PAGE_NOT_FOUND;
1576
1577 return VINF_SUCCESS;
1578}
1579
1580/**
1581 * Returns monitor description based on CSAM tag
1582 *
1583 * @return description string
1584 * @param enmTag Owner tag
1585 */
1586const char *csamGetMonitorDescription(CSAMTAG enmTag)
1587{
1588 if (enmTag == CSAM_TAG_PATM)
1589 return "CSAM-PATM self-modifying code monitor handler";
1590 else
1591 if (enmTag == CSAM_TAG_REM)
1592 return "CSAM-REM self-modifying code monitor handler";
1593 Assert(enmTag == CSAM_TAG_CSAM);
1594 return "CSAM self-modifying code monitor handler";
1595}
1596
1597/**
1598 * Adds page record to our lookup tree
1599 *
1600 * @returns CSAMPAGE ptr or NULL if failure
1601 * @param pVM The VM to operate on.
1602 * @param GCPtr Page address
1603 * @param enmTag Owner tag
1604 * @param fCode32 16 or 32 bits code
1605 * @param fMonitorInvalidation Monitor page invalidation flag
1606 */
1607static PCSAMPAGE csamCreatePageRecord(PVM pVM, RTRCPTR GCPtr, CSAMTAG enmTag, bool fCode32, bool fMonitorInvalidation)
1608{
1609 PCSAMPAGEREC pPage;
1610 int rc;
1611 bool ret;
1612
1613 Log(("New page record for %VRv\n", GCPtr & PAGE_BASE_GC_MASK));
1614
1615 pPage = (PCSAMPAGEREC)MMR3HeapAllocZ(pVM, MM_TAG_CSAM_PATCH, sizeof(CSAMPAGEREC));
1616 if (pPage == NULL)
1617 {
1618 AssertMsgFailed(("csamCreatePageRecord: Out of memory!!!!\n"));
1619 return NULL;
1620 }
1621 /* Round down to page boundary. */
1622 GCPtr = (GCPtr & PAGE_BASE_GC_MASK);
1623 pPage->Core.Key = (AVLPVKEY)GCPtr;
1624 pPage->page.pPageGC = GCPtr;
1625 pPage->page.fCode32 = fCode32;
1626 pPage->page.fMonitorInvalidation = fMonitorInvalidation;
1627 pPage->page.enmTag = enmTag;
1628 pPage->page.fMonitorActive = false;
1629 pPage->page.pBitmap = (uint8_t *)MMR3HeapAllocZ(pVM, MM_TAG_CSAM_PATCH, PAGE_SIZE/sizeof(uint8_t));
1630 rc = PGMGstGetPage(pVM, GCPtr, &pPage->page.fFlags, &pPage->page.GCPhys);
1631 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
1632
1633 pPage->page.u64Hash = csamR3CalcPageHash(pVM, GCPtr);
1634 ret = RTAvlPVInsert(&pVM->csam.s.pPageTree, &pPage->Core);
1635 Assert(ret);
1636
1637#ifdef CSAM_MONITOR_CODE_PAGES
1638 AssertRelease(!fInCSAMCodePageInvalidate);
1639
1640 switch (enmTag)
1641 {
1642 case CSAM_TAG_PATM:
1643 case CSAM_TAG_REM:
1644#ifdef CSAM_MONITOR_CSAM_CODE_PAGES
1645 case CSAM_TAG_CSAM:
1646#endif
1647 {
1648 int rc = PGMR3HandlerVirtualRegister(pVM, PGMVIRTHANDLERTYPE_WRITE, GCPtr, GCPtr + (PAGE_SIZE - 1) /* inclusive! */,
1649 (fMonitorInvalidation) ? CSAMCodePageInvalidate : 0, CSAMCodePageWriteHandler, "CSAMGCCodePageWriteHandler", 0,
1650 csamGetMonitorDescription(enmTag));
1651 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PGM_HANDLER_VIRTUAL_CONFLICT, ("PGMR3HandlerVirtualRegisterEx %VRv failed with %Vrc\n", GCPtr, rc));
1652 if (VBOX_FAILURE(rc))
1653 Log(("PGMR3HandlerVirtualRegisterEx for %VRv failed with %Vrc\n", GCPtr, rc));
1654
1655 /* Could fail, because it's already monitored. Don't treat that condition as fatal. */
1656
1657 /* Prefetch it in case it's not there yet. */
1658 rc = PGMPrefetchPage(pVM, GCPtr);
1659 AssertRC(rc);
1660
1661 rc = PGMShwModifyPage(pVM, GCPtr, 1, 0, ~(uint64_t)X86_PTE_RW);
1662 Assert(rc == VINF_SUCCESS || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT);
1663
1664 pPage->page.fMonitorActive = true;
1665 STAM_COUNTER_INC(&pVM->csam.s.StatPageMonitor);
1666 break;
1667 }
1668 default:
1669 break; /* to shut up GCC */
1670 }
1671
1672 Log(("csamCreatePageRecord %VRv HCPhys=%VGp\n", GCPtr, pPage->page.GCPhys));
1673
1674#ifdef VBOX_WITH_STATISTICS
1675 switch (enmTag)
1676 {
1677 case CSAM_TAG_CSAM:
1678 STAM_COUNTER_INC(&pVM->csam.s.StatPageCSAM);
1679 break;
1680 case CSAM_TAG_PATM:
1681 STAM_COUNTER_INC(&pVM->csam.s.StatPagePATM);
1682 break;
1683 case CSAM_TAG_REM:
1684 STAM_COUNTER_INC(&pVM->csam.s.StatPageREM);
1685 break;
1686 default:
1687 break; /* to shut up GCC */
1688 }
1689#endif
1690
1691#endif
1692
1693 STAM_COUNTER_INC(&pVM->csam.s.StatNrPages);
1694 if (fMonitorInvalidation)
1695 STAM_COUNTER_INC(&pVM->csam.s.StatNrPagesInv);
1696
1697 return &pPage->page;
1698}
1699
1700/**
1701 * Monitors a code page (if not already monitored)
1702 *
1703 * @returns VBox status code
1704 * @param pVM The VM to operate on.
1705 * @param pPageAddrGC The page to monitor
1706 * @param enmTag Monitor tag
1707 */
1708VMMR3DECL(int) CSAMR3MonitorPage(PVM pVM, RTRCPTR pPageAddrGC, CSAMTAG enmTag)
1709{
1710 PCSAMPAGEREC pPageRec = NULL;
1711 int rc;
1712 bool fMonitorInvalidation;
1713
1714 /* Dirty pages must be handled before calling this function!. */
1715 Assert(!pVM->csam.s.cDirtyPages);
1716
1717 if (pVM->csam.s.fScanningStarted == false)
1718 return VINF_SUCCESS; /* too early */
1719
1720 pPageAddrGC &= PAGE_BASE_GC_MASK;
1721
1722 Log(("CSAMR3MonitorPage %VRv %d\n", pPageAddrGC, enmTag));
1723
1724 /** @todo implicit assumption */
1725 fMonitorInvalidation = (enmTag == CSAM_TAG_PATM);
1726
1727 pPageRec = (PCSAMPAGEREC)RTAvlPVGet(&pVM->csam.s.pPageTree, (AVLPVKEY)pPageAddrGC);
1728 if (pPageRec == NULL)
1729 {
1730 uint64_t fFlags;
1731
1732 rc = PGMGstGetPage(pVM, pPageAddrGC, &fFlags, NULL);
1733 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
1734 if ( rc == VINF_SUCCESS
1735 && (fFlags & X86_PTE_US))
1736 {
1737 /* We don't care about user pages. */
1738 STAM_COUNTER_INC(&pVM->csam.s.StatNrUserPages);
1739 return VINF_SUCCESS;
1740 }
1741
1742 csamCreatePageRecord(pVM, pPageAddrGC, enmTag, true /* 32 bits code */, fMonitorInvalidation);
1743
1744 pPageRec = (PCSAMPAGEREC)RTAvlPVGet(&pVM->csam.s.pPageTree, (AVLPVKEY)pPageAddrGC);
1745 Assert(pPageRec);
1746 }
1747 /** @todo reference count */
1748
1749#ifdef CSAM_MONITOR_CSAM_CODE_PAGES
1750 Assert(pPageRec->page.fMonitorActive);
1751#endif
1752
1753#ifdef CSAM_MONITOR_CODE_PAGES
1754 if (!pPageRec->page.fMonitorActive)
1755 {
1756 Log(("CSAMR3MonitorPage: activate monitoring for %VRv\n", pPageAddrGC));
1757
1758 rc = PGMR3HandlerVirtualRegister(pVM, PGMVIRTHANDLERTYPE_WRITE, pPageAddrGC, pPageAddrGC + (PAGE_SIZE - 1) /* inclusive! */,
1759 (fMonitorInvalidation) ? CSAMCodePageInvalidate : 0, CSAMCodePageWriteHandler, "CSAMGCCodePageWriteHandler", 0,
1760 csamGetMonitorDescription(enmTag));
1761 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PGM_HANDLER_VIRTUAL_CONFLICT, ("PGMR3HandlerVirtualRegisterEx %VRv failed with %Vrc\n", pPageAddrGC, rc));
1762 if (VBOX_FAILURE(rc))
1763 Log(("PGMR3HandlerVirtualRegisterEx for %VRv failed with %Vrc\n", pPageAddrGC, rc));
1764
1765 /* Could fail, because it's already monitored. Don't treat that condition as fatal. */
1766
1767 /* Prefetch it in case it's not there yet. */
1768 rc = PGMPrefetchPage(pVM, pPageAddrGC);
1769 AssertRC(rc);
1770
1771 rc = PGMShwModifyPage(pVM, pPageAddrGC, 1, 0, ~(uint64_t)X86_PTE_RW);
1772 Assert(rc == VINF_SUCCESS || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT);
1773
1774 STAM_COUNTER_INC(&pVM->csam.s.StatPageMonitor);
1775
1776 pPageRec->page.fMonitorActive = true;
1777 pPageRec->page.fMonitorInvalidation = fMonitorInvalidation;
1778 }
1779 else
1780 if ( !pPageRec->page.fMonitorInvalidation
1781 && fMonitorInvalidation)
1782 {
1783 Assert(pPageRec->page.fMonitorActive);
1784 PGMHandlerVirtualChangeInvalidateCallback(pVM, pPageRec->page.pPageGC, CSAMCodePageInvalidate);
1785 pPageRec->page.fMonitorInvalidation = true;
1786 STAM_COUNTER_INC(&pVM->csam.s.StatNrPagesInv);
1787
1788 /* Prefetch it in case it's not there yet. */
1789 rc = PGMPrefetchPage(pVM, pPageAddrGC);
1790 AssertRC(rc);
1791
1792 /* Make sure it's readonly. Page invalidation may have modified the attributes. */
1793 rc = PGMShwModifyPage(pVM, pPageAddrGC, 1, 0, ~(uint64_t)X86_PTE_RW);
1794 Assert(rc == VINF_SUCCESS || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT);
1795 }
1796
1797#if 0 /* def VBOX_STRICT -> very annoying) */
1798 if (pPageRec->page.fMonitorActive)
1799 {
1800 uint64_t fPageShw;
1801 RTHCPHYS GCPhys;
1802 rc = PGMShwGetPage(pVM, pPageAddrGC, &fPageShw, &GCPhys);
1803// AssertMsg( (rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT)
1804// || !(fPageShw & X86_PTE_RW)
1805// || (pPageRec->page.GCPhys == 0), ("Shadow page flags for %VRv (%VHp) aren't readonly (%VX64)!!\n", pPageAddrGC, GCPhys, fPageShw));
1806 }
1807#endif
1808
1809 if (pPageRec->page.GCPhys == 0)
1810 {
1811 /* Prefetch it in case it's not there yet. */
1812 rc = PGMPrefetchPage(pVM, pPageAddrGC);
1813 AssertRC(rc);
1814 /* The page was changed behind our back. It won't be made read-only until the next SyncCR3, so force it here. */
1815 rc = PGMShwModifyPage(pVM, pPageAddrGC, 1, 0, ~(uint64_t)X86_PTE_RW);
1816 Assert(rc == VINF_SUCCESS || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT);
1817 }
1818#endif /* CSAM_MONITOR_CODE_PAGES */
1819 return VINF_SUCCESS;
1820}
1821
1822/**
1823 * Unmonitors a code page
1824 *
1825 * @returns VBox status code
1826 * @param pVM The VM to operate on.
1827 * @param pPageAddrGC The page to monitor
1828 * @param enmTag Monitor tag
1829 */
1830VMMR3DECL(int) CSAMR3UnmonitorPage(PVM pVM, RTRCPTR pPageAddrGC, CSAMTAG enmTag)
1831{
1832 pPageAddrGC &= PAGE_BASE_GC_MASK;
1833
1834 Log(("CSAMR3UnmonitorPage %VRv %d\n", pPageAddrGC, enmTag));
1835
1836 Assert(enmTag == CSAM_TAG_REM);
1837
1838#ifdef VBOX_STRICT
1839 PCSAMPAGEREC pPageRec;
1840
1841 pPageRec = (PCSAMPAGEREC)RTAvlPVGet(&pVM->csam.s.pPageTree, (AVLPVKEY)pPageAddrGC);
1842 Assert(pPageRec && pPageRec->page.enmTag == enmTag);
1843#endif
1844 return CSAMR3RemovePage(pVM, pPageAddrGC);
1845}
1846
1847/**
1848 * Removes a page record from our lookup tree
1849 *
1850 * @returns VBox status code
1851 * @param pVM The VM to operate on.
1852 * @param GCPtr Page address
1853 */
1854static int csamRemovePageRecord(PVM pVM, RTRCPTR GCPtr)
1855{
1856 PCSAMPAGEREC pPageRec;
1857
1858 Log(("csamRemovePageRecord %VRv\n", GCPtr));
1859 pPageRec = (PCSAMPAGEREC)RTAvlPVRemove(&pVM->csam.s.pPageTree, (AVLPVKEY)GCPtr);
1860
1861 if (pPageRec)
1862 {
1863 STAM_COUNTER_INC(&pVM->csam.s.StatNrRemovedPages);
1864
1865#ifdef CSAM_MONITOR_CODE_PAGES
1866 if (pPageRec->page.fMonitorActive)
1867 {
1868 /* @todo -> this is expensive (cr3 reload)!!!
1869 * if this happens often, then reuse it instead!!!
1870 */
1871 Assert(!fInCSAMCodePageInvalidate);
1872 STAM_COUNTER_DEC(&pVM->csam.s.StatPageMonitor);
1873 PGMHandlerVirtualDeregister(pVM, GCPtr);
1874 }
1875 if (pPageRec->page.enmTag == CSAM_TAG_PATM)
1876 {
1877 /* Make sure the recompiler flushes its cache as this page is no longer monitored. */
1878 STAM_COUNTER_INC(&pVM->csam.s.StatPageRemoveREMFlush);
1879 CPUMSetChangedFlags(pVM, CPUM_CHANGED_GLOBAL_TLB_FLUSH);
1880 }
1881#endif
1882
1883#ifdef VBOX_WITH_STATISTICS
1884 switch (pPageRec->page.enmTag)
1885 {
1886 case CSAM_TAG_CSAM:
1887 STAM_COUNTER_DEC(&pVM->csam.s.StatPageCSAM);
1888 break;
1889 case CSAM_TAG_PATM:
1890 STAM_COUNTER_DEC(&pVM->csam.s.StatPagePATM);
1891 break;
1892 case CSAM_TAG_REM:
1893 STAM_COUNTER_DEC(&pVM->csam.s.StatPageREM);
1894 break;
1895 default:
1896 break; /* to shut up GCC */
1897 }
1898#endif
1899
1900 if (pPageRec->page.pBitmap) MMR3HeapFree(pPageRec->page.pBitmap);
1901 MMR3HeapFree(pPageRec);
1902 }
1903 else
1904 AssertFailed();
1905
1906 return VINF_SUCCESS;
1907}
1908
1909/**
1910 * Callback for delayed writes from non-EMT threads
1911 *
1912 * @param pVM VM Handle.
1913 * @param GCPtr The virtual address the guest is writing to. (not correct if it's an alias!)
1914 * @param cbBuf How much it's reading/writing.
1915 */
1916static DECLCALLBACK(void) CSAMDelayedWriteHandler(PVM pVM, RTRCPTR GCPtr, size_t cbBuf)
1917{
1918 int rc = PATMR3PatchWrite(pVM, GCPtr, cbBuf);
1919 AssertRC(rc);
1920}
1921
1922/**
1923 * #PF Handler callback for virtual access handler ranges.
1924 *
1925 * Important to realize that a physical page in a range can have aliases, and
1926 * for ALL and WRITE handlers these will also trigger.
1927 *
1928 * @returns VINF_SUCCESS if the handler have carried out the operation.
1929 * @returns VINF_PGM_HANDLER_DO_DEFAULT if the caller should carry out the access operation.
1930 * @param pVM VM Handle.
1931 * @param GCPtr The virtual address the guest is writing to. (not correct if it's an alias!)
1932 * @param pvPtr The HC mapping of that address.
1933 * @param pvBuf What the guest is reading/writing.
1934 * @param cbBuf How much it's reading/writing.
1935 * @param enmAccessType The access type.
1936 * @param pvUser User argument.
1937 */
1938static DECLCALLBACK(int) CSAMCodePageWriteHandler(PVM pVM, RTGCPTR GCPtr, void *pvPtr, void *pvBuf, size_t cbBuf, PGMACCESSTYPE enmAccessType, void *pvUser)
1939{
1940 int rc;
1941
1942 Assert(enmAccessType == PGMACCESSTYPE_WRITE);
1943 Log(("CSAMCodePageWriteHandler: write to %VGv size=%d\n", GCPtr, cbBuf));
1944
1945 if (VM_IS_EMT(pVM))
1946 {
1947 rc = PATMR3PatchWrite(pVM, GCPtr, cbBuf);
1948 }
1949 else
1950 {
1951 /* Queue the write instead otherwise we'll get concurrency issues. */
1952 /** @note in theory not correct to let it write the data first before disabling a patch!
1953 * (if it writes the same data as the patch jump and we replace it with obsolete opcodes)
1954 */
1955 Log(("CSAMCodePageWriteHandler: delayed write!\n"));
1956 AssertCompileSize(RTRCPTR, 4);
1957 rc = VMR3ReqCallEx(pVM, NULL, 0, VMREQFLAGS_NO_WAIT | VMREQFLAGS_VOID,
1958 (PFNRT)CSAMDelayedWriteHandler, 3, pVM, (RTRCPTR)GCPtr, cbBuf);
1959 }
1960 AssertRC(rc);
1961
1962 return VINF_PGM_HANDLER_DO_DEFAULT;
1963}
1964
1965/**
1966 * #PF Handler callback for invalidation of virtual access handler ranges.
1967 *
1968 * @param pVM VM Handle.
1969 * @param GCPtr The virtual address the guest has changed.
1970 */
1971static DECLCALLBACK(int) CSAMCodePageInvalidate(PVM pVM, RTGCPTR GCPtr)
1972{
1973 fInCSAMCodePageInvalidate = true;
1974 LogFlow(("CSAMCodePageInvalidate %VGv\n", GCPtr));
1975 /** @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. */
1976 csamFlushPage(pVM, GCPtr, false /* don't remove page! */);
1977 fInCSAMCodePageInvalidate = false;
1978 return VINF_SUCCESS;
1979}
1980
1981/**
1982 * Check if the current instruction has already been checked before
1983 *
1984 * @returns VBox status code. (trap handled or not)
1985 * @param pVM The VM to operate on.
1986 * @param pInstr Instruction pointer
1987 * @param pPage CSAM patch structure pointer
1988 */
1989bool csamIsCodeScanned(PVM pVM, RTRCPTR pInstr, PCSAMPAGE *pPage)
1990{
1991 PCSAMPAGEREC pPageRec;
1992 uint32_t offset;
1993
1994 STAM_PROFILE_START(&pVM->csam.s.StatTimeCheckAddr, a);
1995
1996 offset = pInstr & PAGE_OFFSET_MASK;
1997 pInstr = pInstr & PAGE_BASE_GC_MASK;
1998
1999 Assert(pPage);
2000
2001 if (*pPage && (*pPage)->pPageGC == pInstr)
2002 {
2003 if ((*pPage)->pBitmap == NULL || ASMBitTest((*pPage)->pBitmap, offset))
2004 {
2005 STAM_COUNTER_ADD(&pVM->csam.s.StatNrKnownPagesHC, 1);
2006 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeCheckAddr, a);
2007 return true;
2008 }
2009 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeCheckAddr, a);
2010 return false;
2011 }
2012
2013 pPageRec = (PCSAMPAGEREC)RTAvlPVGet(&pVM->csam.s.pPageTree, (AVLPVKEY)pInstr);
2014 if (pPageRec)
2015 {
2016 if (pPage) *pPage= &pPageRec->page;
2017 if (pPageRec->page.pBitmap == NULL || ASMBitTest(pPageRec->page.pBitmap, offset))
2018 {
2019 STAM_COUNTER_ADD(&pVM->csam.s.StatNrKnownPagesHC, 1);
2020 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeCheckAddr, a);
2021 return true;
2022 }
2023 }
2024 else
2025 {
2026 if (pPage) *pPage = NULL;
2027 }
2028 STAM_PROFILE_STOP(&pVM->csam.s.StatTimeCheckAddr, a);
2029 return false;
2030}
2031
2032/**
2033 * Mark an instruction in a page as scanned/not scanned
2034 *
2035 * @param pVM The VM to operate on.
2036 * @param pPage Patch structure pointer
2037 * @param pInstr Instruction pointer
2038 * @param opsize Instruction size
2039 * @param fScanned Mark as scanned or not
2040 */
2041static void csamMarkCode(PVM pVM, PCSAMPAGE pPage, RTRCPTR pInstr, uint32_t opsize, bool fScanned)
2042{
2043 LogFlow(("csamMarkCodeAsScanned %VRv opsize=%d\n", pInstr, opsize));
2044 CSAMMarkPage(pVM, pInstr, fScanned);
2045
2046 /** @todo should recreate empty bitmap if !fScanned */
2047 if (pPage->pBitmap == NULL)
2048 return;
2049
2050 if (fScanned)
2051 {
2052 // retn instructions can be scanned more than once
2053 if (ASMBitTest(pPage->pBitmap, pInstr & PAGE_OFFSET_MASK) == 0)
2054 {
2055 pPage->uSize += opsize;
2056 STAM_COUNTER_ADD(&pVM->csam.s.StatNrInstr, 1);
2057 }
2058 if (pPage->uSize >= PAGE_SIZE)
2059 {
2060 Log(("Scanned full page (%VRv) -> free bitmap\n", pInstr & PAGE_BASE_GC_MASK));
2061 MMR3HeapFree(pPage->pBitmap);
2062 pPage->pBitmap = NULL;
2063 }
2064 else
2065 ASMBitSet(pPage->pBitmap, pInstr & PAGE_OFFSET_MASK);
2066 }
2067 else
2068 ASMBitClear(pPage->pBitmap, pInstr & PAGE_OFFSET_MASK);
2069}
2070
2071/**
2072 * Mark an instruction in a page as scanned/not scanned
2073 *
2074 * @returns VBox status code.
2075 * @param pVM The VM to operate on.
2076 * @param pInstr Instruction pointer
2077 * @param opsize Instruction size
2078 * @param fScanned Mark as scanned or not
2079 */
2080VMMR3DECL(int) CSAMR3MarkCode(PVM pVM, RTRCPTR pInstr, uint32_t opsize, bool fScanned)
2081{
2082 PCSAMPAGE pPage = 0;
2083
2084 Assert(!fScanned); /* other case not implemented. */
2085 Assert(!PATMIsPatchGCAddr(pVM, pInstr));
2086
2087 if (csamIsCodeScanned(pVM, pInstr, &pPage) == false)
2088 {
2089 Assert(fScanned == true); /* other case should not be possible */
2090 return VINF_SUCCESS;
2091 }
2092
2093 Log(("CSAMR3MarkCode: %VRv size=%d fScanned=%d\n", pInstr, opsize, fScanned));
2094 csamMarkCode(pVM, pPage, pInstr, opsize, fScanned);
2095 return VINF_SUCCESS;
2096}
2097
2098
2099/**
2100 * Scan and analyse code
2101 *
2102 * @returns VBox status code.
2103 * @param pVM The VM to operate on.
2104 * @param pCtxCore CPU context
2105 * @param pInstrGC Instruction pointer
2106 */
2107VMMR3DECL(int) CSAMR3CheckCodeEx(PVM pVM, PCPUMCTXCORE pCtxCore, RTRCPTR pInstrGC)
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 /* Assuming 32 bits code for now. */
2118 Assert(SELMGetCpuModeFromSelector(pVM, pCtxCore->eflags, pCtxCore->cs, &pCtxCore->csHid) == CPUMODE_32BIT);
2119
2120 pInstrGC = SELMToFlat(pVM, DIS_SELREG_CS, pCtxCore, pInstrGC);
2121 return CSAMR3CheckCode(pVM, pInstrGC);
2122 }
2123 return VINF_SUCCESS;
2124}
2125
2126/**
2127 * Scan and analyse code
2128 *
2129 * @returns VBox status code.
2130 * @param pVM The VM to operate on.
2131 * @param pInstrGC Instruction pointer (0:32 virtual address)
2132 */
2133VMMR3DECL(int) CSAMR3CheckCode(PVM pVM, RTRCPTR pInstrGC)
2134{
2135 int rc;
2136 PCSAMPAGE pPage = NULL;
2137
2138 if (EMIsRawRing0Enabled(pVM) == false || PATMIsPatchGCAddr(pVM, pInstrGC) == true)
2139 {
2140 // No use
2141 return VINF_SUCCESS;
2142 }
2143
2144 if (CSAMIsEnabled(pVM))
2145 {
2146 // Cache record for PATMGCVirtToHCVirt
2147 CSAMP2GLOOKUPREC cacheRec = {0};
2148
2149 STAM_PROFILE_START(&pVM->csam.s.StatTime, a);
2150 rc = csamAnalyseCallCodeStream(pVM, pInstrGC, pInstrGC, true /* 32 bits code */, CSAMR3AnalyseCallback, pPage, &cacheRec);
2151 STAM_PROFILE_STOP(&pVM->csam.s.StatTime, a);
2152 if (rc != VINF_SUCCESS)
2153 {
2154 Log(("csamAnalyseCodeStream failed with %d\n", rc));
2155 return rc;
2156 }
2157 }
2158 return VINF_SUCCESS;
2159}
2160
2161/**
2162 * Flush dirty code pages
2163 *
2164 * @returns VBox status code.
2165 * @param pVM The VM to operate on.
2166 */
2167static int csamR3FlushDirtyPages(PVM pVM)
2168{
2169 STAM_PROFILE_START(&pVM->csam.s.StatFlushDirtyPages, a);
2170
2171 for (uint32_t i=0;i<pVM->csam.s.cDirtyPages;i++)
2172 {
2173 int rc;
2174 PCSAMPAGEREC pPageRec;
2175 RTRCPTR GCPtr = pVM->csam.s.pvDirtyBasePage[i];
2176
2177 GCPtr = GCPtr & PAGE_BASE_GC_MASK;
2178
2179 /* Notify the recompiler that this page has been changed. */
2180 REMR3NotifyCodePageChanged(pVM, GCPtr);
2181
2182 /* Enable write protection again. (use the fault address as it might be an alias) */
2183 rc = PGMShwModifyPage(pVM, pVM->csam.s.pvDirtyFaultPage[i], 1, 0, ~(uint64_t)X86_PTE_RW);
2184 Assert(rc == VINF_SUCCESS || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT);
2185
2186 Log(("CSAMR3FlushDirtyPages: flush %VRv (modifypage rc=%Vrc)\n", pVM->csam.s.pvDirtyBasePage[i], rc));
2187
2188 pPageRec = (PCSAMPAGEREC)RTAvlPVGet(&pVM->csam.s.pPageTree, (AVLPVKEY)GCPtr);
2189 if (pPageRec && pPageRec->page.enmTag == CSAM_TAG_REM)
2190 {
2191 uint64_t fFlags;
2192
2193 rc = PGMGstGetPage(pVM, GCPtr, &fFlags, NULL);
2194 AssertMsg(VBOX_SUCCESS(rc) || rc == VERR_PAGE_NOT_PRESENT || rc == VERR_PAGE_TABLE_NOT_PRESENT, ("rc = %Vrc\n", rc));
2195 if ( rc == VINF_SUCCESS
2196 && (fFlags & X86_PTE_US))
2197 {
2198 /* We don't care about user pages. */
2199 csamRemovePageRecord(pVM, GCPtr);
2200 STAM_COUNTER_INC(&pVM->csam.s.StatNrUserPages);
2201 }
2202 }
2203 }
2204 pVM->csam.s.cDirtyPages = 0;
2205 STAM_PROFILE_STOP(&pVM->csam.s.StatFlushDirtyPages, a);
2206 return VINF_SUCCESS;
2207}
2208
2209/**
2210 * Flush potential new code pages
2211 *
2212 * @returns VBox status code.
2213 * @param pVM The VM to operate on.
2214 */
2215static int csamR3FlushCodePages(PVM pVM)
2216{
2217 for (uint32_t i=0;i<pVM->csam.s.cPossibleCodePages;i++)
2218 {
2219 RTRCPTR GCPtr = pVM->csam.s.pvPossibleCodePage[i];
2220
2221 GCPtr = GCPtr & PAGE_BASE_GC_MASK;
2222
2223 Log(("csamR3FlushCodePages: %VRv\n", GCPtr));
2224 PGMShwSetPage(pVM, GCPtr, 1, 0);
2225 /* Resync the page to make sure instruction fetch will fault */
2226 CSAMMarkPage(pVM, GCPtr, false);
2227 }
2228 pVM->csam.s.cPossibleCodePages = 0;
2229 return VINF_SUCCESS;
2230}
2231
2232/**
2233 * Perform any pending actions
2234 *
2235 * @returns VBox status code.
2236 * @param pVM The VM to operate on.
2237 */
2238VMMR3DECL(int) CSAMR3DoPendingAction(PVM pVM)
2239{
2240 csamR3FlushDirtyPages(pVM);
2241 csamR3FlushCodePages(pVM);
2242
2243 VM_FF_CLEAR(pVM, VM_FF_CSAM_PENDING_ACTION);
2244 return VINF_SUCCESS;
2245}
2246
2247/**
2248 * Analyse interrupt and trap gates
2249 *
2250 * @returns VBox status code.
2251 * @param pVM The VM to operate on.
2252 * @param iGate Start gate
2253 * @param cGates Number of gates to check
2254 */
2255VMMR3DECL(int) CSAMR3CheckGates(PVM pVM, uint32_t iGate, uint32_t cGates)
2256{
2257 uint16_t cbIDT;
2258 RTRCPTR GCPtrIDT = CPUMGetGuestIDTR(pVM, &cbIDT);
2259 uint32_t iGateEnd;
2260 uint32_t maxGates;
2261 VBOXIDTE aIDT[256];
2262 PVBOXIDTE pGuestIdte;
2263 int rc;
2264
2265 if (EMIsRawRing0Enabled(pVM) == false)
2266 {
2267 /* Enabling interrupt gates only works when raw ring 0 is enabled. */
2268 //AssertFailed();
2269 return VINF_SUCCESS;
2270 }
2271
2272 /* We only check all gates once during a session */
2273 if ( !pVM->csam.s.fGatesChecked
2274 && cGates != 256)
2275 return VINF_SUCCESS; /* too early */
2276
2277 /* We only check all gates once during a session */
2278 if ( pVM->csam.s.fGatesChecked
2279 && cGates != 1)
2280 return VINF_SUCCESS; /* ignored */
2281
2282 Assert(cGates <= 256);
2283 if (!GCPtrIDT || cGates > 256)
2284 return VERR_INVALID_PARAMETER;
2285
2286 if (cGates != 1)
2287 {
2288 pVM->csam.s.fGatesChecked = true;
2289 for (unsigned i=0;i<RT_ELEMENTS(pVM->csam.s.pvCallInstruction);i++)
2290 {
2291 RTRCPTR pHandler = pVM->csam.s.pvCallInstruction[i];
2292
2293 if (pHandler)
2294 {
2295 CSAMP2GLOOKUPREC cacheRec = {0}; /* Cache record for PATMGCVirtToHCVirt. */
2296 PCSAMPAGE pPage = NULL;
2297
2298 Log(("CSAMCheckGates: checking previous call instruction %VRv\n", pHandler));
2299 STAM_PROFILE_START(&pVM->csam.s.StatTime, a);
2300 rc = csamAnalyseCodeStream(pVM, pHandler, pHandler, true, CSAMR3AnalyseCallback, pPage, &cacheRec);
2301 STAM_PROFILE_STOP(&pVM->csam.s.StatTime, a);
2302 if (rc != VINF_SUCCESS)
2303 {
2304 Log(("CSAMCheckGates: csamAnalyseCodeStream failed with %d\n", rc));
2305 continue;
2306 }
2307 }
2308 }
2309 }
2310
2311 /* Determine valid upper boundary. */
2312 maxGates = (cbIDT+1) / sizeof(VBOXIDTE);
2313 Assert(iGate < maxGates);
2314 if (iGate > maxGates)
2315 return VERR_INVALID_PARAMETER;
2316
2317 if (iGate + cGates > maxGates)
2318 cGates = maxGates - iGate;
2319
2320 GCPtrIDT = GCPtrIDT + iGate * sizeof(VBOXIDTE);
2321 iGateEnd = iGate + cGates;
2322
2323 STAM_PROFILE_START(&pVM->csam.s.StatCheckGates, a);
2324
2325 /*
2326 * Get IDT entries.
2327 */
2328 if (PAGE_ADDRESS(GCPtrIDT) == PAGE_ADDRESS(GCPtrIDT+cGates*sizeof(VBOXIDTE)))
2329 {
2330 /* Just convert the IDT address to a HC pointer. The whole IDT fits in one page. */
2331 rc = PGMPhysGCPtr2HCPtr(pVM, GCPtrIDT, (PRTHCPTR)&pGuestIdte);
2332 if (VBOX_FAILURE(rc))
2333 {
2334 AssertMsgRC(rc, ("Failed to read IDTE! rc=%Vrc\n", rc));
2335 STAM_PROFILE_STOP(&pVM->csam.s.StatCheckGates, a);
2336 return rc;
2337 }
2338 }
2339 else
2340 {
2341 /* Slow method when it crosses a page boundary. */
2342 rc = PGMPhysSimpleReadGCPtr(pVM, aIDT, GCPtrIDT, cGates*sizeof(VBOXIDTE));
2343 if (VBOX_FAILURE(rc))
2344 {
2345 AssertMsgRC(rc, ("Failed to read IDTE! rc=%Vrc\n", rc));
2346 STAM_PROFILE_STOP(&pVM->csam.s.StatCheckGates, a);
2347 return rc;
2348 }
2349 pGuestIdte = &aIDT[0];
2350 }
2351
2352 for (/*iGate*/; iGate<iGateEnd; iGate++, pGuestIdte++)
2353 {
2354 Assert(TRPMR3GetGuestTrapHandler(pVM, iGate) == TRPM_INVALID_HANDLER);
2355
2356 if ( pGuestIdte->Gen.u1Present
2357 && (pGuestIdte->Gen.u5Type2 == VBOX_IDTE_TYPE2_TRAP_32 || pGuestIdte->Gen.u5Type2 == VBOX_IDTE_TYPE2_INT_32)
2358 && (pGuestIdte->Gen.u2DPL == 3 || pGuestIdte->Gen.u2DPL == 0)
2359 )
2360 {
2361 RTRCPTR pHandler;
2362 CSAMP2GLOOKUPREC cacheRec = {0}; /* Cache record for PATMGCVirtToHCVirt. */
2363 PCSAMPAGE pPage = NULL;
2364 SELMSELINFO selInfo;
2365
2366 pHandler = VBOXIDTE_OFFSET(*pGuestIdte);
2367 pHandler = SELMToFlatBySel(pVM, pGuestIdte->Gen.u16SegSel, pHandler);
2368
2369 rc = SELMR3GetSelectorInfo(pVM, pGuestIdte->Gen.u16SegSel, &selInfo);
2370 if ( VBOX_FAILURE(rc)
2371 || selInfo.GCPtrBase != 0
2372 || selInfo.cbLimit != ~0U
2373 )
2374 {
2375 /* Refuse to patch a handler whose idt cs selector isn't wide open. */
2376 Log(("CSAMCheckGates: check gate %d failed due to rc %Vrc GCPtrBase=%VRv limit=%x\n", iGate, rc, selInfo.GCPtrBase, selInfo.cbLimit));
2377 continue;
2378 }
2379
2380
2381 if (pGuestIdte->Gen.u5Type2 == VBOX_IDTE_TYPE2_TRAP_32)
2382 {
2383 Log(("CSAMCheckGates: check trap gate %d at %04X:%08X (flat %VRv)\n", iGate, pGuestIdte->Gen.u16SegSel, VBOXIDTE_OFFSET(*pGuestIdte), pHandler));
2384 }
2385 else
2386 {
2387 Log(("CSAMCheckGates: check interrupt gate %d at %04X:%08X (flat %VRv)\n", iGate, pGuestIdte->Gen.u16SegSel, VBOXIDTE_OFFSET(*pGuestIdte), pHandler));
2388 }
2389
2390 STAM_PROFILE_START(&pVM->csam.s.StatTime, a);
2391 rc = csamAnalyseCodeStream(pVM, pHandler, pHandler, true, CSAMR3AnalyseCallback, pPage, &cacheRec);
2392 STAM_PROFILE_STOP(&pVM->csam.s.StatTime, a);
2393 if (rc != VINF_SUCCESS)
2394 {
2395 Log(("CSAMCheckGates: csamAnalyseCodeStream failed with %d\n", rc));
2396 continue;
2397 }
2398 /* OpenBSD guest specific patch test. */
2399 if (iGate >= 0x20)
2400 {
2401 PCPUMCTX pCtx;
2402 DISCPUSTATE cpu;
2403 RTGCUINTPTR32 aOpenBsdPushCSOffset[3] = {0x03, /* OpenBSD 3.7 & 3.8 */
2404 0x2B, /* OpenBSD 4.0 installation ISO */
2405 0x2F}; /* OpenBSD 4.0 after install */
2406
2407 pCtx = CPUMQueryGuestCtxPtr(pVM);
2408
2409 for (unsigned i=0;i<RT_ELEMENTS(aOpenBsdPushCSOffset);i++)
2410 {
2411 rc = CPUMR3DisasmInstrCPU(pVM, pCtx, pHandler - aOpenBsdPushCSOffset[i], &cpu, NULL);
2412 if ( rc == VINF_SUCCESS
2413 && cpu.pCurInstr->opcode == OP_PUSH
2414 && cpu.pCurInstr->param1 == OP_PARM_REG_CS)
2415 {
2416 rc = PATMR3InstallPatch(pVM, pHandler - aOpenBsdPushCSOffset[i], PATMFL_CODE32 | PATMFL_GUEST_SPECIFIC);
2417 if (VBOX_SUCCESS(rc))
2418 Log(("Installed OpenBSD interrupt handler prefix instruction (push cs) patch\n"));
2419 }
2420 }
2421 }
2422
2423 /* Trap gates and certain interrupt gates. */
2424 uint32_t fPatchFlags = PATMFL_CODE32 | PATMFL_IDTHANDLER;
2425
2426 if (pGuestIdte->Gen.u5Type2 == VBOX_IDTE_TYPE2_TRAP_32)
2427 fPatchFlags |= PATMFL_TRAPHANDLER;
2428 else
2429 fPatchFlags |= PATMFL_INTHANDLER;
2430
2431 switch (iGate) {
2432 case 8:
2433 case 10:
2434 case 11:
2435 case 12:
2436 case 13:
2437 case 14:
2438 case 17:
2439 fPatchFlags |= PATMFL_TRAPHANDLER_WITH_ERRORCODE;
2440 break;
2441 default:
2442 /* No error code. */
2443 break;
2444 }
2445
2446 Log(("Installing %s gate handler for 0x%X at %VRv\n", (pGuestIdte->Gen.u5Type2 == VBOX_IDTE_TYPE2_TRAP_32) ? "trap" : "intr", iGate, pHandler));
2447
2448 rc = PATMR3InstallPatch(pVM, pHandler, fPatchFlags);
2449 if (VBOX_SUCCESS(rc) || rc == VERR_PATM_ALREADY_PATCHED)
2450 {
2451 Log(("Gate handler 0x%X is SAFE!\n", iGate));
2452
2453 RTRCPTR pNewHandlerGC = PATMR3QueryPatchGCPtr(pVM, pHandler);
2454 if (pNewHandlerGC)
2455 {
2456 rc = TRPMR3SetGuestTrapHandler(pVM, iGate, pNewHandlerGC);
2457 if (VBOX_FAILURE(rc))
2458 Log(("TRPMR3SetGuestTrapHandler %d failed with %Vrc\n", iGate, rc));
2459 }
2460 }
2461 }
2462 } /* for */
2463 STAM_PROFILE_STOP(&pVM->csam.s.StatCheckGates, a);
2464 return VINF_SUCCESS;
2465}
2466
2467/**
2468 * Record previous call instruction addresses
2469 *
2470 * @returns VBox status code.
2471 * @param pVM The VM to operate on.
2472 * @param GCPtrCall Call address
2473 */
2474VMMR3DECL(int) CSAMR3RecordCallAddress(PVM pVM, RTRCPTR GCPtrCall)
2475{
2476 for (unsigned i=0;i<RT_ELEMENTS(pVM->csam.s.pvCallInstruction);i++)
2477 {
2478 if (pVM->csam.s.pvCallInstruction[i] == GCPtrCall)
2479 return VINF_SUCCESS;
2480 }
2481
2482 Log(("CSAMR3RecordCallAddress %VRv\n", GCPtrCall));
2483
2484 pVM->csam.s.pvCallInstruction[pVM->csam.s.iCallInstruction++] = GCPtrCall;
2485 if (pVM->csam.s.iCallInstruction >= RT_ELEMENTS(pVM->csam.s.pvCallInstruction))
2486 pVM->csam.s.iCallInstruction = 0;
2487
2488 return VINF_SUCCESS;
2489}
2490
2491
2492/**
2493 * Query CSAM state (enabled/disabled)
2494 *
2495 * @returns 0 - disabled, 1 - enabled
2496 * @param pVM The VM to operate on.
2497 */
2498VMMR3DECL(int) CSAMR3IsEnabled(PVM pVM)
2499{
2500 return pVM->fCSAMEnabled;
2501}
2502
2503#ifdef VBOX_WITH_DEBUGGER
2504/**
2505 * The '.csamoff' command.
2506 *
2507 * @returns VBox status.
2508 * @param pCmd Pointer to the command descriptor (as registered).
2509 * @param pCmdHlp Pointer to command helper functions.
2510 * @param pVM Pointer to the current VM (if any).
2511 * @param paArgs Pointer to (readonly) array of arguments.
2512 * @param cArgs Number of arguments in the array.
2513 */
2514static DECLCALLBACK(int) csamr3CmdOff(PCDBGCCMD pCmd, PDBGCCMDHLP pCmdHlp, PVM pVM, PCDBGCVAR paArgs, unsigned cArgs, PDBGCVAR pResult)
2515{
2516 /*
2517 * Validate input.
2518 */
2519 if (!pVM)
2520 return pCmdHlp->pfnPrintf(pCmdHlp, NULL, "error: The command requires VM to be selected.\n");
2521
2522 CSAMDisableScanning(pVM);
2523 return pCmdHlp->pfnPrintf(pCmdHlp, NULL, "CSAM Scanning disabled\n");
2524}
2525
2526/**
2527 * The '.csamon' command.
2528 *
2529 * @returns VBox status.
2530 * @param pCmd Pointer to the command descriptor (as registered).
2531 * @param pCmdHlp Pointer to command helper functions.
2532 * @param pVM Pointer to the current VM (if any).
2533 * @param paArgs Pointer to (readonly) array of arguments.
2534 * @param cArgs Number of arguments in the array.
2535 */
2536static DECLCALLBACK(int) csamr3CmdOn(PCDBGCCMD pCmd, PDBGCCMDHLP pCmdHlp, PVM pVM, PCDBGCVAR paArgs, unsigned cArgs, PDBGCVAR pResult)
2537{
2538 /*
2539 * Validate input.
2540 */
2541 if (!pVM)
2542 return pCmdHlp->pfnPrintf(pCmdHlp, NULL, "error: The command requires VM to be selected.\n");
2543
2544 CSAMEnableScanning(pVM);
2545 return pCmdHlp->pfnPrintf(pCmdHlp, NULL, "CSAM Scanning enabled\n");
2546}
2547#endif
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