memsafer-r3.cpp@ 106580

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1	/* $Id: memsafer-r3.cpp 106061 2024-09-16 14:03:52Z vboxsync $ */
2	/** @file
3	* IPRT - Memory Allocate for Sensitive Data, generic heap-based implementation.
4	*/
5
6	/*
7	* Copyright (C) 2006-2024 Oracle and/or its affiliates.
8	*
9	* This file is part of VirtualBox base platform packages, as
10	* available from https://www.virtualbox.org.
11	*
12	* This program is free software; you can redistribute it and/or
13	* modify it under the terms of the GNU General Public License
14	* as published by the Free Software Foundation, in version 3 of the
15	* License.
16	*
17	* This program is distributed in the hope that it will be useful, but
18	* WITHOUT ANY WARRANTY; without even the implied warranty of
19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20	* General Public License for more details.
21	*
22	* You should have received a copy of the GNU General Public License
23	* along with this program; if not, see <https://www.gnu.org/licenses>.
24	*
25	* The contents of this file may alternatively be used under the terms
26	* of the Common Development and Distribution License Version 1.0
27	* (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
28	* in the VirtualBox distribution, in which case the provisions of the
29	* CDDL are applicable instead of those of the GPL.
30	*
31	* You may elect to license modified versions of this file under the
32	* terms and conditions of either the GPL or the CDDL or both.
33	*
34	* SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
35	*/
36
37
38	/*********************************************************************************************************************************
39	* Header Files *
40	*********************************************************************************************************************************/
41	#include "internal/iprt.h"
42	#include <iprt/memsafer.h>
43
44	#include <iprt/asm.h>
45	#include <iprt/assert.h>
46	#include <iprt/avl.h>
47	#include <iprt/critsect.h>
48	#include <iprt/err.h>
49	#include <iprt/mem.h>
50	#include <iprt/once.h>
51	#include <iprt/rand.h>
52	#include <iprt/param.h>
53	#include <iprt/string.h>
54	#include <iprt/system.h>
55	#ifdef IN_SUP_R3
56	# include <VBox/sup.h>
57	#endif
58
59
60	/*********************************************************************************************************************************
61	* Defined Constants And Macros *
62	*********************************************************************************************************************************/
63	/** Allocation size alignment (power of two). */
64	#define RTMEMSAFER_ALIGN 16
65
66
67	/*********************************************************************************************************************************
68	* Structures and Typedefs *
69	*********************************************************************************************************************************/
70	/**
71	* Allocators.
72	*/
73	typedef enum RTMEMSAFERALLOCATOR
74	{
75	/** Invalid method. */
76	RTMEMSAFERALLOCATOR_INVALID = 0,
77	/** RTMemPageAlloc. */
78	RTMEMSAFERALLOCATOR_RTMEMPAGE,
79	/** SUPR3PageAllocEx. */
80	RTMEMSAFERALLOCATOR_SUPR3
81	} RTMEMSAFERALLOCATOR;
82
83	/**
84	* Tracking node (lives on normal heap).
85	*/
86	typedef struct RTMEMSAFERNODE
87	{
88	/** Node core.
89	* The core key is a scrambled pointer the user memory. */
90	AVLPVNODECORE Core;
91	/** The allocation flags. */
92	uint32_t fFlags;
93	/** The offset into the allocation of the user memory. */
94	uint32_t offUser;
95	/** The requested allocation size. */
96	size_t cbUser;
97	/** The allocation size in pages, this includes the two guard pages. */
98	uint32_t cPages;
99	/** The allocator used for this node. */
100	RTMEMSAFERALLOCATOR enmAllocator;
101	/** XOR scrambler value for memory. */
102	uintptr_t uScramblerXor;
103	} RTMEMSAFERNODE;
104	/** Pointer to an allocation tracking node. */
105	typedef RTMEMSAFERNODE *PRTMEMSAFERNODE;
106
107
108	/*********************************************************************************************************************************
109	* Global Variables *
110	*********************************************************************************************************************************/
111	/** Init once structure for this module. */
112	static RTONCE g_MemSaferOnce = RTONCE_INITIALIZER;
113	/** Critical section protecting the allocation tree. */
114	static RTCRITSECTRW g_MemSaferCritSect;
115	/** Tree of allocation nodes. */
116	static AVLPVTREE g_pMemSaferTree;
117	/** XOR scrambler value pointers. */
118	static uintptr_t g_uMemSaferPtrScramblerXor;
119	/** Pointer rotate shift count.*/
120	static uintptr_t g_cMemSaferPtrScramblerRotate;
121
122
123	/**
124	* @callback_method_impl{FNRTONCE, Inits globals.}
125	*/
126	static DECLCALLBACK(int32_t) rtMemSaferOnceInit(void *pvUserIgnore)
127	{
128	RT_NOREF_PV(pvUserIgnore);
129
130	g_uMemSaferPtrScramblerXor = (uintptr_t)RTRandU64();
131	g_cMemSaferPtrScramblerRotate = RTRandU32Ex(0, ARCH_BITS - 1);
132	return RTCritSectRwInit(&g_MemSaferCritSect);
133	}
134
135
136	/**
137	* @callback_method_impl{PFNRTONCECLEANUP, Cleans up globals.}
138	*/
139	static DECLCALLBACK(void) rtMemSaferOnceTerm(void *pvUser, bool fLazyCleanUpOk)
140	{
141	RT_NOREF_PV(pvUser);
142
143	if (!fLazyCleanUpOk)
144	{
145	RTCritSectRwDelete(&g_MemSaferCritSect);
146	Assert(!g_pMemSaferTree);
147	}
148	}
149
150
151
152	DECLINLINE(void ) rtMemSaferScramblePointer(void pvUser)
153	{
154	uintptr_t uPtr = (uintptr_t)pvUser;
155	uPtr ^= g_uMemSaferPtrScramblerXor;
156	#if ARCH_BITS == 64
157	uPtr = ASMRotateRightU64(uPtr, g_cMemSaferPtrScramblerRotate);
158	#elif ARCH_BITS == 32
159	uPtr = ASMRotateRightU32(uPtr, g_cMemSaferPtrScramblerRotate);
160	#else
161	# error "Unsupported/missing ARCH_BITS."
162	#endif
163	return (void *)uPtr;
164	}
165
166
167	/**
168	* Inserts a tracking node into the tree.
169	*
170	* @param pThis The allocation tracking node to insert.
171	*/
172	static void rtMemSaferNodeInsert(PRTMEMSAFERNODE pThis)
173	{
174	RTCritSectRwEnterExcl(&g_MemSaferCritSect);
175	pThis->Core.Key = rtMemSaferScramblePointer(pThis->Core.Key);
176	bool fRc = RTAvlPVInsert(&g_pMemSaferTree, &pThis->Core);
177	RTCritSectRwLeaveExcl(&g_MemSaferCritSect);
178	Assert(fRc); NOREF(fRc);
179	}
180
181
182	/**
183	* Finds a tracking node into the tree.
184	*
185	* @returns The allocation tracking node for @a pvUser. NULL if not found.
186	* @param pvUser The user pointer to the allocation.
187	*/
188	static PRTMEMSAFERNODE rtMemSaferNodeLookup(void *pvUser)
189	{
190	void *pvKey = rtMemSaferScramblePointer(pvUser);
191	RTCritSectRwEnterShared(&g_MemSaferCritSect);
192	PRTMEMSAFERNODE pThis = (PRTMEMSAFERNODE)RTAvlPVGet(&g_pMemSaferTree, pvKey);
193	RTCritSectRwLeaveShared(&g_MemSaferCritSect);
194	return pThis;
195	}
196
197
198	/**
199	* Removes a tracking node from the tree.
200	*
201	* @returns The allocation tracking node for @a pvUser. NULL if not found.
202	* @param pvUser The user pointer to the allocation.
203	*/
204	static PRTMEMSAFERNODE rtMemSaferNodeRemove(void *pvUser)
205	{
206	void *pvKey = rtMemSaferScramblePointer(pvUser);
207	RTCritSectRwEnterExcl(&g_MemSaferCritSect);
208	PRTMEMSAFERNODE pThis = (PRTMEMSAFERNODE)RTAvlPVRemove(&g_pMemSaferTree, pvKey);
209	RTCritSectRwLeaveExcl(&g_MemSaferCritSect);
210	return pThis;
211	}
212
213
214	RTDECL(int) RTMemSaferScramble(void *pv, size_t cb)
215	{
216	PRTMEMSAFERNODE pThis = rtMemSaferNodeLookup(pv);
217	AssertReturn(pThis, VERR_INVALID_POINTER);
218	AssertMsgReturn(cb == pThis->cbUser, ("cb=%#zx != %#zx\n", cb, pThis->cbUser), VERR_INVALID_PARAMETER);
219
220	/* First time we get a new xor value. */
221	if (!pThis->uScramblerXor)
222	pThis->uScramblerXor = (uintptr_t)RTRandU64();
223
224	/* Note! This isn't supposed to be safe, just less obvious. */
225	uintptr_t pu = (uintptr_t )pv;
226	cb = RT_ALIGN_Z(cb, RTMEMSAFER_ALIGN);
227	while (cb > 0)
228	{
229	*pu ^= pThis->uScramblerXor;
230	pu++;
231	cb -= sizeof(*pu);
232	}
233
234	return VINF_SUCCESS;
235	}
236	RT_EXPORT_SYMBOL(RTMemSaferScramble);
237
238
239	RTDECL(int) RTMemSaferUnscramble(void *pv, size_t cb)
240	{
241	PRTMEMSAFERNODE pThis = rtMemSaferNodeLookup(pv);
242	AssertReturn(pThis, VERR_INVALID_POINTER);
243	AssertMsgReturn(cb == pThis->cbUser, ("cb=%#zx != %#zx\n", cb, pThis->cbUser), VERR_INVALID_PARAMETER);
244
245	/* Note! This isn't supposed to be safe, just less obvious. */
246	uintptr_t pu = (uintptr_t )pv;
247	cb = RT_ALIGN_Z(cb, RTMEMSAFER_ALIGN);
248	while (cb > 0)
249	{
250	*pu ^= pThis->uScramblerXor;
251	pu++;
252	cb -= sizeof(*pu);
253	}
254
255	return VINF_SUCCESS;
256	}
257	RT_EXPORT_SYMBOL(RTMemSaferUnscramble);
258
259
260	/**
261	* Initializes the pages.
262	*
263	* Fills the memory with random bytes in order to make it less obvious where the
264	* secret data starts and ends. We also zero the user memory in case the
265	* allocator does not do this.
266	*
267	* @param pThis The allocation tracer node. The Core.Key member
268	* will be set.
269	* @param pvPages The pages to initialize.
270	*/
271	static void rtMemSaferInitializePages(PRTMEMSAFERNODE pThis, void *pvPages)
272	{
273	uint32_t const cbPage = RTSystemGetPageSize();
274	RTRandBytes(pvPages, cbPage + pThis->offUser);
275
276	uint8_t pbUser = (uint8_t )pvPages + cbPage + pThis->offUser;
277	pThis->Core.Key = pbUser;
278	RT_BZERO(pbUser, pThis->cbUser); /* paranoia */
279
280	RTRandBytes(pbUser + pThis->cbUser, (size_t)pThis->cPages * cbPage - cbPage - pThis->offUser - pThis->cbUser);
281	}
282
283
284	/**
285	* Allocates and initializes pages from the support driver and initializes it.
286	*
287	* @returns VBox status code.
288	* @param pThis The allocator node. Core.Key will be set on successful
289	* return (unscrambled).
290	*/
291	static int rtMemSaferSupR3AllocPages(PRTMEMSAFERNODE pThis)
292	{
293	#ifdef IN_SUP_R3
294	/*
295	* Try allocate the memory.
296	*/
297	void *pvPages;
298	int rc = SUPR3PageAllocEx(pThis->cPages, 0 /* fFlags /, &pvPages, NULL / pR0Ptr /, NULL / paPages */);
299	if (RT_SUCCESS(rc))
300	{
301	rtMemSaferInitializePages(pThis, pvPages);
302
303	/*
304	* On darwin we cannot allocate pages without an R0 mapping and
305	* SUPR3PageAllocEx falls back to another method which is incompatible with
306	* the way SUPR3PageProtect works. Ignore changing the protection of the guard
307	* pages.
308	*/
309	#ifdef RT_OS_DARWIN
310	return VINF_SUCCESS;
311	#else
312	/*
313	* Configure the guard pages.
314	* SUPR3PageProtect isn't supported on all hosts, we ignore that.
315	*/
316	uint32_t const cbPage = RTSystemGetPageSize();
317	rc = SUPR3PageProtect(pvPages, NIL_RTR0PTR, 0, cbPage, RTMEM_PROT_NONE);
318	if (RT_SUCCESS(rc))
319	{
320	rc = SUPR3PageProtect(pvPages, NIL_RTR0PTR, (pThis->cPages - 1) * cbPage, cbPage, RTMEM_PROT_NONE);
321	if (RT_SUCCESS(rc))
322	return VINF_SUCCESS;
323	SUPR3PageProtect(pvPages, NIL_RTR0PTR, 0, cbPage, RTMEM_PROT_READ \| RTMEM_PROT_WRITE);
324	}
325	else if (rc == VERR_NOT_SUPPORTED)
326	return VINF_SUCCESS;
327
328	/* failed. */
329	int rc2 = SUPR3PageFreeEx(pvPages, pThis->cPages); AssertRC(rc2);
330	#endif
331	}
332	return rc;
333
334	#else /* !IN_SUP_R3 */
335	RT_NOREF_PV(pThis);
336	return VERR_NOT_SUPPORTED;
337	#endif /* !IN_SUP_R3 */
338	}
339
340
341	/**
342	* Allocates and initializes pages using the IPRT page allocator API.
343	*
344	* @returns VBox status code.
345	* @param pThis The allocator node. Core.Key will be set on successful
346	* return (unscrambled).
347	*/
348	static int rtMemSaferMemAllocPages(PRTMEMSAFERNODE pThis)
349	{
350	/*
351	* Try allocate the memory.
352	*/
353	uint32_t const cbPage = RTSystemGetPageSize();
354	int rc = VINF_SUCCESS;
355	void pvPages = RTMemPageAllocEx((size_t)pThis->cPages cbPage,
356	RTMEMPAGEALLOC_F_ADVISE_LOCKED \| RTMEMPAGEALLOC_F_ADVISE_NO_DUMP \| RTMEMPAGEALLOC_F_ZERO);
357	if (pvPages)
358	{
359	rtMemSaferInitializePages(pThis, pvPages);
360
361	/*
362	* Configure the guard pages.
363	*/
364	rc = RTMemProtect(pvPages, cbPage, RTMEM_PROT_NONE);
365	if (RT_SUCCESS(rc))
366	{
367	rc = RTMemProtect((uint8_t )pvPages + (size_t)(pThis->cPages - 1U) cbPage, cbPage, RTMEM_PROT_NONE);
368	if (RT_SUCCESS(rc))
369	return VINF_SUCCESS;
370	rc = RTMemProtect(pvPages, cbPage, RTMEM_PROT_READ \| RTMEM_PROT_WRITE);
371	}
372
373	/* failed. */
374	RTMemPageFree(pvPages, (size_t)pThis->cPages * cbPage);
375	}
376	else
377	rc = VERR_NO_PAGE_MEMORY;
378
379	return rc;
380	}
381
382
383	RTDECL(int) RTMemSaferAllocZExTag(void *ppvNew, size_t cb, uint32_t fFlags, const char pszTag) RT_NO_THROW_DEF
384	{
385	RT_NOREF_PV(pszTag);
386
387	/*
388	* Validate input.
389	*/
390	AssertPtrReturn(ppvNew, VERR_INVALID_PARAMETER);
391	*ppvNew = NULL;
392	AssertReturn(cb, VERR_INVALID_PARAMETER);
393	uint32_t const cbPage = RTSystemGetPageSize();
394	AssertReturn(cb <= 32U_1M - cbPage 3U, VERR_ALLOCATION_TOO_BIG); /* Max 32 MB minus padding and guard pages. */
395	AssertReturn(!(fFlags & ~RTMEMSAFER_F_VALID_MASK), VERR_INVALID_FLAGS);
396
397	/*
398	* Initialize globals.
399	*/
400	int rc = RTOnceEx(&g_MemSaferOnce, rtMemSaferOnceInit, rtMemSaferOnceTerm, NULL);
401	if (RT_SUCCESS(rc))
402	{
403	/*
404	* Allocate a tracker node first.
405	*/
406	PRTMEMSAFERNODE pThis = (PRTMEMSAFERNODE)RTMemAllocZ(sizeof(RTMEMSAFERNODE));
407	if (pThis)
408	{
409	/*
410	* Prepare the allocation.
411	*/
412	pThis->cbUser = cb;
413	pThis->offUser = (RTRandU32Ex(0, 128) * RTMEMSAFER_ALIGN) & RTSystemGetPageOffsetMask();
414
415	size_t cbNeeded = pThis->offUser + pThis->cbUser;
416	cbNeeded = RT_ALIGN_Z(cbNeeded, cbPage);
417
418	pThis->cPages = (uint32_t)(cbNeeded / cbPage) + 2; /* +2 for guard pages */
419
420	/*
421	* Try allocate the memory, using the best allocator by default and
422	* falling back on the less safe one.
423	*/
424	if (!(fFlags & RTMEMSAFER_F_NO_SUPLIB_ALLOC))
425	rc = rtMemSaferSupR3AllocPages(pThis);
426	else
427	rc = VERR_NO_PAGE_MEMORY;
428	if (RT_SUCCESS(rc))
429	pThis->enmAllocator = RTMEMSAFERALLOCATOR_SUPR3;
430	else if (!(fFlags & RTMEMSAFER_F_REQUIRE_NOT_PAGABLE))
431	{
432	rc = rtMemSaferMemAllocPages(pThis);
433	if (RT_SUCCESS(rc))
434	pThis->enmAllocator = RTMEMSAFERALLOCATOR_RTMEMPAGE;
435	}
436	if (RT_SUCCESS(rc))
437	{
438	/*
439	* Insert the node.
440	*/
441	*ppvNew = pThis->Core.Key;
442	rtMemSaferNodeInsert(pThis); /* (Scrambles Core.Key) */
443	return VINF_SUCCESS;
444	}
445
446	RTMemFree(pThis);
447	}
448	else
449	rc = VERR_NO_MEMORY;
450	}
451	return rc;
452	}
453	RT_EXPORT_SYMBOL(RTMemSaferAllocZExTag);
454
455
456	RTDECL(void) RTMemSaferFree(void *pv, size_t cb) RT_NO_THROW_DEF
457	{
458	if (pv)
459	{
460	PRTMEMSAFERNODE pThis = rtMemSaferNodeRemove(pv);
461	AssertReturnVoid(pThis);
462	if (cb == 0) /* for openssl use */
463	cb = pThis->cbUser;
464	else
465	AssertMsg(cb == pThis->cbUser, ("cb=%#zx != %#zx\n", cb, pThis->cbUser));
466
467	/*
468	* Wipe the user memory first.
469	*/
470	RTMemWipeThoroughly(pv, RT_ALIGN_Z(cb, RTMEMSAFER_ALIGN), 3);
471
472	/*
473	* Free the pages.
474	*/
475	uint32_t const cbPage = RTSystemGetPageSize();
476	uint8_t pbPages = (uint8_t )pv - pThis->offUser - cbPage;
477	size_t cbPages = (size_t)pThis->cPages * cbPage;
478	switch (pThis->enmAllocator)
479	{
480	#ifdef IN_SUP_R3
481	case RTMEMSAFERALLOCATOR_SUPR3:
482	SUPR3PageProtect(pbPages, NIL_RTR0PTR, 0, cbPage, RTMEM_PROT_READ \| RTMEM_PROT_WRITE);
483	SUPR3PageProtect(pbPages, NIL_RTR0PTR, (uint32_t)(cbPages - cbPage), cbPage, RTMEM_PROT_READ \| RTMEM_PROT_WRITE);
484	SUPR3PageFreeEx(pbPages, pThis->cPages);
485	break;
486	#endif
487	case RTMEMSAFERALLOCATOR_RTMEMPAGE:
488	RTMemProtect(pbPages, cbPage, RTMEM_PROT_READ \| RTMEM_PROT_WRITE);
489	RTMemProtect(pbPages + cbPages - cbPage, cbPage, RTMEM_PROT_READ \| RTMEM_PROT_WRITE);
490	RTMemPageFree(pbPages, cbPages);
491	break;
492
493	default:
494	AssertFailed();
495	}
496
497	/*
498	* Free the tracking node.
499	*/
500	pThis->Core.Key = NULL;
501	pThis->offUser = 0;
502	pThis->cbUser = 0;
503	RTMemFree(pThis);
504	}
505	else
506	Assert(cb == 0);
507	}
508	RT_EXPORT_SYMBOL(RTMemSaferFree);
509
510
511	RTDECL(size_t) RTMemSaferGetSize(void *pv) RT_NO_THROW_DEF
512	{
513	size_t cbRet = 0;
514	if (pv)
515	{
516	/*
517	* We use this API for testing whether pv is a safer allocation or not,
518	* so we may be called before the allocators. Thus, it's prudent to
519	* make sure initialization has taken place before attempting to enter
520	* the critical section and such.
521	*/
522	int rc = RTOnceEx(&g_MemSaferOnce, rtMemSaferOnceInit, rtMemSaferOnceTerm, NULL);
523	if (RT_SUCCESS(rc))
524	{
525	void *pvKey = rtMemSaferScramblePointer(pv);
526	RTCritSectRwEnterShared(&g_MemSaferCritSect);
527	PRTMEMSAFERNODE pThis = (PRTMEMSAFERNODE)RTAvlPVGet(&g_pMemSaferTree, pvKey);
528	if (pThis)
529	cbRet = pThis->cbUser;
530	RTCritSectRwLeaveShared(&g_MemSaferCritSect);
531	}
532	}
533	return cbRet;
534	}
535	RT_EXPORT_SYMBOL(RTMemSaferGetSize);
536
537
538	/**
539	* The simplest reallocation method: allocate new block, copy over the data,
540	* free old block.
541	*/
542	static int rtMemSaferReallocSimpler(size_t cbOld, void pvOld, size_t cbNew, void ppvNew, uint32_t fFlags, const char pszTag)
543	{
544	void *pvNew;
545	int rc = RTMemSaferAllocZExTag(&pvNew, cbNew, fFlags, pszTag);
546	if (RT_SUCCESS(rc))
547	{
548	memcpy(pvNew, pvOld, RT_MIN(cbNew, cbOld));
549	RTMemSaferFree(pvOld, cbOld);
550	*ppvNew = pvNew;
551	}
552	return rc;
553	}
554
555
556	RTDECL(int) RTMemSaferReallocZExTag(size_t cbOld, void pvOld, size_t cbNew, void ppvNew, uint32_t fFlags, const char pszTag) RT_NO_THROW_DEF
557	{
558	int rc;
559	/* Real realloc. */
560	if (cbNew && cbOld)
561	{
562	PRTMEMSAFERNODE pThis = rtMemSaferNodeLookup(pvOld);
563	AssertReturn(pThis, VERR_INVALID_POINTER);
564	AssertMsgStmt(cbOld == pThis->cbUser, ("cbOld=%#zx != %#zx\n", cbOld, pThis->cbUser), cbOld = pThis->cbUser);
565
566	if (pThis->fFlags == fFlags)
567	{
568	if (cbNew > cbOld)
569	{
570	/*
571	* Is the enough room for us to grow?
572	*/
573	size_t cbMax = (size_t)(pThis->cPages - 2) * RTSystemGetPageSize();
574	if (cbNew <= cbMax)
575	{
576	size_t const cbAdded = (cbNew - cbOld);
577	size_t const cbAfter = cbMax - pThis->offUser - cbOld;
578	if (cbAfter >= cbAdded)
579	{
580	/*
581	* Sufficient space after the current allocation.
582	*/
583	uint8_t pbNewSpace = (uint8_t )pvOld + cbOld;
584	RT_BZERO(pbNewSpace, cbAdded);
585	*ppvNew = pvOld;
586	}
587	else
588	{
589	/*
590	* Have to move the allocation to make enough room at the
591	* end. In order to make it a little less predictable and
592	* maybe avoid a relocation or two in the next call, divide
593	* the page offset by four until it it fits.
594	*/
595	AssertReturn(rtMemSaferNodeRemove(pvOld) == pThis, VERR_INTERNAL_ERROR_3);
596	uint32_t offNewUser = pThis->offUser;
597	do
598	offNewUser = offNewUser / 2;
599	while ((pThis->offUser - offNewUser) + cbAfter < cbAdded);
600	offNewUser &= ~(RTMEMSAFER_ALIGN - 1U);
601
602	uint32_t const cbMove = pThis->offUser - offNewUser;
603	uint8_t pbNew = (uint8_t )pvOld - cbMove;
604	memmove(pbNew, pvOld, cbOld);
605
606	RT_BZERO(pbNew + cbOld, cbAdded);
607	if (cbMove > cbAdded)
608	RTMemWipeThoroughly(pbNew + cbNew, cbMove - cbAdded, 3);
609
610	pThis->offUser = offNewUser;
611	pThis->Core.Key = pbNew;
612	*ppvNew = pbNew;
613
614	rtMemSaferNodeInsert(pThis);
615	}
616	Assert(((uintptr_t)*ppvNew & RTSystemGetPageOffsetMask()) == pThis->offUser);
617	pThis->cbUser = cbNew;
618	rc = VINF_SUCCESS;
619	}
620	else
621	{
622	/*
623	* Not enough space, allocate a new block and copy over the data.
624	*/
625	rc = rtMemSaferReallocSimpler(cbOld, pvOld, cbNew, ppvNew, fFlags, pszTag);
626	}
627	}
628	else
629	{
630	/*
631	* Shrinking the allocation, just wipe the memory that is no longer
632	* being used.
633	*/
634	if (cbNew != cbOld)
635	{
636	uint8_t pbAbandond = (uint8_t )pvOld + cbNew;
637	RTMemWipeThoroughly(pbAbandond, cbOld - cbNew, 3);
638	}
639	pThis->cbUser = cbNew;
640	*ppvNew = pvOld;
641	rc = VINF_SUCCESS;
642	}
643	}
644	else if (!pThis->fFlags)
645	{
646	/*
647	* New flags added. Allocate a new block and copy over the old one.
648	*/
649	rc = rtMemSaferReallocSimpler(cbOld, pvOld, cbNew, ppvNew, fFlags, pszTag);
650	}
651	else
652	{
653	/* Compatible flags. */
654	AssertMsgFailed(("fFlags=%#x old=%#x\n", fFlags, pThis->fFlags));
655	rc = VERR_INVALID_FLAGS;
656	}
657	}
658	/*
659	* First allocation. Pass it on.
660	*/
661	else if (!cbOld)
662	{
663	Assert(pvOld == NULL);
664	rc = RTMemSaferAllocZExTag(ppvNew, cbNew, fFlags, pszTag);
665	}
666	/*
667	* Free operation. Pass it on.
668	*/
669	else
670	{
671	RTMemSaferFree(pvOld, cbOld);
672	*ppvNew = NULL;
673	rc = VINF_SUCCESS;
674	}
675	return rc;
676	}
677	RT_EXPORT_SYMBOL(RTMemSaferReallocZExTag);
678
679
680	RTDECL(void ) RTMemSaferAllocZTag(size_t cb, const char pszTag) RT_NO_THROW_DEF
681	{
682	void *pvNew = NULL;
683	int rc = RTMemSaferAllocZExTag(&pvNew, cb, 0 /fFlags/, pszTag);
684	if (RT_SUCCESS(rc))
685	return pvNew;
686	return NULL;
687	}
688	RT_EXPORT_SYMBOL(RTMemSaferAllocZTag);
689
690
691	RTDECL(void ) RTMemSaferReallocZTag(size_t cbOld, void pvOld, size_t cbNew, const char *pszTag) RT_NO_THROW_DEF
692	{
693	void *pvNew = NULL;
694	int rc = RTMemSaferReallocZExTag(cbOld, pvOld, cbNew, &pvNew, 0 /fFlags/, pszTag);
695	if (RT_SUCCESS(rc))
696	return pvNew;
697	return NULL;
698	}
699	RT_EXPORT_SYMBOL(RTMemSaferReallocZTag);
700

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source: vbox/trunk/src/VBox/Runtime/r3/memsafer-r3.cpp@ 106580

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