DBGPlugInLinux.cpp@ 71930

Last change on this file since 71930 was 69820, checked in by vboxsync, 7 years ago
Debugger/Linux: Cope with KASLR being used when probing for a Linux guest
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1	/* $Id: DBGPlugInLinux.cpp 69820 2017-11-24 11:43:38Z vboxsync $ */
2	/** @file
3	* DBGPlugInLinux - Debugger and Guest OS Digger Plugin For Linux.
4	*/
5
6	/*
7	* Copyright (C) 2008-2017 Oracle Corporation
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
18
19	/*********************************************************************************************************************************
20	* Header Files *
21	*********************************************************************************************************************************/
22	#define LOG_GROUP LOG_GROUP_DBGF /// @todo add new log group.
23	#include "DBGPlugIns.h"
24	#include "DBGPlugInCommonELF.h"
25	#include <VBox/vmm/dbgf.h>
26	#include <VBox/dis.h>
27	#include <iprt/file.h>
28	#include <iprt/string.h>
29	#include <iprt/mem.h>
30	#include <iprt/stream.h>
31	#include <iprt/ctype.h>
32	#include <iprt/vfs.h>
33	#include <iprt/zip.h>
34
35
36	/*********************************************************************************************************************************
37	* Structures and Typedefs *
38	*********************************************************************************************************************************/
39
40	/** @name InternalLinux structures
41	* @{ */
42
43
44	/** @} */
45
46
47	/**
48	* Config item type.
49	*/
50	typedef enum DBGDIGGERLINUXCFGITEMTYPE
51	{
52	/** Invalid type. */
53	DBGDIGGERLINUXCFGITEMTYPE_INVALID = 0,
54	/** String. */
55	DBGDIGGERLINUXCFGITEMTYPE_STRING,
56	/** Number. */
57	DBGDIGGERLINUXCFGITEMTYPE_NUMBER,
58	/** Flag whether this feature is included in the
59	* kernel or as a module. */
60	DBGDIGGERLINUXCFGITEMTYPE_FLAG
61	} DBGDIGGERLINUXCFGITEMTYPE;
62
63	/**
64	* Item in the config database.
65	*/
66	typedef struct DBGDIGGERLINUXCFGITEM
67	{
68	/** String space core. */
69	RTSTRSPACECORE Core;
70	/** Config item type. */
71	DBGDIGGERLINUXCFGITEMTYPE enmType;
72	/** Data based on the type. */
73	union
74	{
75	/** Number. */
76	int64_t i64Num;
77	/** Flag. */
78	bool fModule;
79	/** String - variable in size. */
80	char aszString[1];
81	} u;
82	} DBGDIGGERLINUXCFGITEM;
83	/** Pointer to a config database item. */
84	typedef DBGDIGGERLINUXCFGITEM *PDBGDIGGERLINUXCFGITEM;
85	/** Pointer to a const config database item. */
86	typedef const DBGDIGGERLINUXCFGITEM *PCDBGDIGGERLINUXCFGITEM;
87
88	/**
89	* Linux guest OS digger instance data.
90	*/
91	typedef struct DBGDIGGERLINUX
92	{
93	/** Whether the information is valid or not.
94	* (For fending off illegal interface method calls.) */
95	bool fValid;
96	/** Set if 64-bit, clear if 32-bit. */
97	bool f64Bit;
98	/** Set if the kallsyms table uses relative addressing, clear
99	* if absolute addresses are used. */
100	bool fRelKrnlAddr;
101	/** The relative base when kernel symbols use offsets rather than
102	* absolute addresses. */
103	RTGCUINTPTR uKernelRelativeBase;
104
105	/** The address of the linux banner.
106	* This is set during probing. */
107	DBGFADDRESS AddrLinuxBanner;
108	/** Kernel base address.
109	* This is set during probing, refined during kallsyms parsing. */
110	DBGFADDRESS AddrKernelBase;
111	/** The kernel size. */
112	uint32_t cbKernel;
113
114	/** The number of kernel symbols (kallsyms_num_syms).
115	* This is set during init. */
116	uint32_t cKernelSymbols;
117	/** The size of the kernel name table (sizeof(kallsyms_names)). */
118	uint32_t cbKernelNames;
119	/** Number of entries in the kernel_markers table. */
120	uint32_t cKernelNameMarkers;
121	/** The size of the kernel symbol token table. */
122	uint32_t cbKernelTokenTable;
123	/** The address of the encoded kernel symbol names (kallsyms_names). */
124	DBGFADDRESS AddrKernelNames;
125	/** The address of the kernel symbol addresses (kallsyms_addresses). */
126	DBGFADDRESS AddrKernelAddresses;
127	/** The address of the kernel symbol name markers (kallsyms_markers). */
128	DBGFADDRESS AddrKernelNameMarkers;
129	/** The address of the kernel symbol token table (kallsyms_token_table). */
130	DBGFADDRESS AddrKernelTokenTable;
131	/** The address of the kernel symbol token index table (kallsyms_token_index). */
132	DBGFADDRESS AddrKernelTokenIndex;
133
134	/** The kernel message log interface. */
135	DBGFOSIDMESG IDmesg;
136
137	/** The config database root. */
138	RTSTRSPACE hCfgDb;
139	} DBGDIGGERLINUX;
140	/** Pointer to the linux guest OS digger instance data. */
141	typedef DBGDIGGERLINUX *PDBGDIGGERLINUX;
142
143
144	/**
145	* The current printk_log structure.
146	*/
147	typedef struct LNXPRINTKHDR
148	{
149	/** Monotonic timestamp. */
150	uint64_t nsTimestamp;
151	/** The total size of this message record. */
152	uint16_t cbTotal;
153	/** The size of the text part (immediately follows the header). */
154	uint16_t cbText;
155	/** The size of the optional dictionary part (follows the text). */
156	uint16_t cbDict;
157	/** The syslog facility number. */
158	uint8_t bFacility;
159	/** First 5 bits are internal flags, next 3 bits are log level. */
160	uint8_t fFlagsAndLevel;
161	} LNXPRINTKHDR;
162	AssertCompileSize(LNXPRINTKHDR, 2*sizeof(uint64_t));
163	/** Pointer to linux printk_log header. */
164	typedef LNXPRINTKHDR *PLNXPRINTKHDR;
165	/** Pointer to linux const printk_log header. */
166	typedef LNXPRINTKHDR const *PCLNXPRINTKHDR;
167
168
169	/*********************************************************************************************************************************
170	* Defined Constants And Macros *
171	*********************************************************************************************************************************/
172	/** First kernel map address for 32bit Linux hosts (__START_KERNEL_map). */
173	#define LNX32_KERNEL_ADDRESS_START UINT32_C(0xc0000000)
174	/** First kernel map address for 64bit Linux hosts (__START_KERNEL_map). */
175	#define LNX64_KERNEL_ADDRESS_START UINT64_C(0xffffffff80000000)
176	/** Validates a 32-bit linux kernel address */
177	#define LNX32_VALID_ADDRESS(Addr) ((Addr) > UINT32_C(0x80000000) && (Addr) < UINT32_C(0xfffff000))
178	/** Validates a 64-bit linux kernel address */
179	#define LNX64_VALID_ADDRESS(Addr) ((Addr) > UINT64_C(0xffff800000000000) && (Addr) < UINT64_C(0xfffffffffffff000))
180
181	/** The max kernel size. */
182	#define LNX_MAX_KERNEL_SIZE UINT32_C(0x0f000000)
183
184	/** The maximum size we expect for kallsyms_names. */
185	#define LNX_MAX_KALLSYMS_NAMES_SIZE UINT32_C(0x200000)
186	/** The maximum size we expect for kallsyms_token_table. */
187	#define LNX_MAX_KALLSYMS_TOKEN_TABLE_SIZE UINT32_C(0x10000)
188	/** The minimum number of symbols we expect in kallsyms_num_syms. */
189	#define LNX_MIN_KALLSYMS_SYMBOLS UINT32_C(2048)
190	/** The maximum number of symbols we expect in kallsyms_num_syms. */
191	#define LNX_MAX_KALLSYMS_SYMBOLS UINT32_C(1048576)
192	/** The min length an encoded symbol in kallsyms_names is expected to have. */
193	#define LNX_MIN_KALLSYMS_ENC_LENGTH UINT8_C(1)
194	/** The max length an encoded symbol in kallsyms_names is expected to have.
195	* @todo check real life here. */
196	#define LNX_MAX_KALLSYMS_ENC_LENGTH UINT8_C(28)
197	/** The approximate maximum length of a string token. */
198	#define LNX_MAX_KALLSYMS_TOKEN_LEN UINT16_C(32)
199	/** Maximum compressed config size expected. */
200	#define LNX_MAX_COMPRESSED_CFG_SIZE _1M
201
202	/** Module tag for linux ('linuxmod' on little endian ASCII systems). */
203	#define DIG_LNX_MOD_TAG UINT64_C(0x545f5d78758e898c)
204
205
206	/*********************************************************************************************************************************
207	* Internal Functions *
208	*********************************************************************************************************************************/
209	static DECLCALLBACK(int) dbgDiggerLinuxInit(PUVM pUVM, void *pvData);
210
211
212	/*********************************************************************************************************************************
213	* Global Variables *
214	*********************************************************************************************************************************/
215	/** Table of common linux kernel addresses. */
216	static uint64_t g_au64LnxKernelAddresses[] =
217	{
218	UINT64_C(0xc0100000),
219	UINT64_C(0x90100000),
220	UINT64_C(0xffffffff80200000)
221	};
222
223	static const uint8_t g_abLinuxVersion[] = "Linux version ";
224
225	/**
226	* Converts a given offset into an absolute address if relative kernel offsets are used for
227	* kallsyms.
228	*
229	* @returns The absolute kernel address.
230	* @param pThis The Linux digger data.
231	* @param uOffset The offset to convert.
232	*/
233	DECLINLINE(RTGCUINTPTR) dbgDiggerLinuxConvOffsetToAddr(PDBGDIGGERLINUX pThis, int32_t uOffset)
234	{
235	RTGCUINTPTR uAddr;
236
237	/*
238	* How the absolute address is calculated from the offset depends on the
239	* CONFIG_KALLSYMS_ABSOLUTE_PERCPU config which is only set for 64bit
240	* SMP kernels (we assume that all 64bit kernels always have SMP enabled too).
241	*/
242	if (pThis->f64Bit)
243	{
244	if (uOffset >= 0)
245	uAddr = uOffset;
246	else
247	uAddr = pThis->uKernelRelativeBase - 1 - uOffset;
248	}
249	else
250	uAddr = pThis->uKernelRelativeBase + (uint32_t)uOffset;
251
252	return uAddr;
253	}
254
255	/**
256	* Disassembles a simple getter returning the value for it.
257	*
258	* @returns VBox status code.
259	* @param pThis The Linux digger data.
260	* @param pUVM The VM handle.
261	* @param hMod The module to use.
262	* @param pszSymbol The symbol of the getter.
263	* @param pvVal Where to store the value on success.
264	* @param cbVal Size of the value in bytes.
265	*/
266	static int dbgDiggerLinuxDisassembleSimpleGetter(PDBGDIGGERLINUX pThis, PUVM pUVM, RTDBGMOD hMod,
267	const char pszSymbol, void pvVal, uint32_t cbVal)
268	{
269	int rc = VINF_SUCCESS;
270
271	RTDBGSYMBOL SymInfo;
272	rc = RTDbgModSymbolByName(hMod, pszSymbol, &SymInfo);
273	if (RT_SUCCESS(rc))
274	{
275	/*
276	* Do the diassembling. Disassemble until a ret instruction is encountered
277	* or a limit is reached (don't want to disassemble for too long as the getter
278	* should be short).
279	* push and pop instructions are skipped as well as any mov instructions not
280	* touching the rax or eax register (depending on the size of the value).
281	*/
282	unsigned cInstrDisassembled = 0;
283	uint32_t offInstr = 0;
284	bool fRet = false;
285	DISSTATE DisState;
286	RT_ZERO(DisState);
287
288	do
289	{
290	DBGFADDRESS Addr;
291	RTGCPTR GCPtrCur = (RTGCPTR)SymInfo.Value + pThis->AddrKernelBase.FlatPtr + offInstr;
292	DBGFR3AddrFromFlat(pUVM, &Addr, GCPtrCur);
293
294	/* Prefetch the instruction. */
295	uint8_t abInstr[32];
296	rc = DBGFR3MemRead(pUVM, 0 /idCpu/, &Addr, &abInstr[0], sizeof(abInstr));
297	if (RT_SUCCESS(rc))
298	{
299	uint32_t cbInstr = 0;
300
301	rc = DISInstr(&abInstr[0], pThis->f64Bit ? DISCPUMODE_64BIT : DISCPUMODE_32BIT, &DisState, &cbInstr);
302	if (RT_SUCCESS(rc))
303	{
304	switch (DisState.pCurInstr->uOpcode)
305	{
306	case OP_PUSH:
307	case OP_POP:
308	case OP_NOP:
309	case OP_LEA:
310	break;
311	case OP_RETN:
312	/* Getter returned, abort disassembling. */
313	fRet = true;
314	break;
315	case OP_MOV:
316	/*
317	* Check that the destination is either rax or eax depending on the
318	* value size.
319	*
320	* Param1 is the destination and Param2 the source.
321	*/
322	if ( ( ( (DisState.Param1.fUse & (DISUSE_BASE \| DISUSE_REG_GEN32))
323	&& cbVal == sizeof(uint32_t))
324	\|\| ( (DisState.Param1.fUse & (DISUSE_BASE \| DISUSE_REG_GEN64))
325	&& cbVal == sizeof(uint64_t)))
326	&& DisState.Param1.Base.idxGenReg == DISGREG_RAX)
327	{
328	/* Parse the source. */
329	if (DisState.Param2.fUse & (DISUSE_IMMEDIATE32 \| DISUSE_IMMEDIATE64))
330	memcpy(pvVal, &DisState.Param2.uValue, cbVal);
331	else if (DisState.Param2.fUse & (DISUSE_RIPDISPLACEMENT32\|DISUSE_DISPLACEMENT32\|DISUSE_DISPLACEMENT64))
332	{
333	RTGCPTR GCPtrVal = 0;
334
335	if (DisState.Param2.fUse & DISUSE_RIPDISPLACEMENT32)
336	GCPtrVal = GCPtrCur + DisState.Param2.uDisp.i32 + cbInstr;
337	else if (DisState.Param2.fUse & DISUSE_DISPLACEMENT32)
338	GCPtrVal = (RTGCPTR)DisState.Param2.uDisp.u32;
339	else if (DisState.Param2.fUse & DISUSE_DISPLACEMENT64)
340	GCPtrVal = (RTGCPTR)DisState.Param2.uDisp.u64;
341	else
342	AssertMsgFailedBreakStmt(("Invalid displacement\n"), rc = VERR_INVALID_STATE);
343
344	DBGFADDRESS AddrVal;
345	rc = DBGFR3MemRead(pUVM, 0 /idCpu/,
346	DBGFR3AddrFromFlat(pUVM, &AddrVal, GCPtrVal),
347	pvVal, cbVal);
348	}
349	}
350	break;
351	default:
352	/* All other instructions will cause an error for now (playing safe here). */
353	rc = VERR_INVALID_PARAMETER;
354	break;
355	}
356	cInstrDisassembled++;
357	offInstr += cbInstr;
358	}
359	}
360	} while ( RT_SUCCESS(rc)
361	&& cInstrDisassembled < 20
362	&& !fRet);
363	}
364
365	return rc;
366	}
367
368	/**
369	* Try to get at the log buffer starting address and size by disassembling emit_log_char.
370	*
371	* @returns VBox status code.
372	* @param pThis The Linux digger data.
373	* @param pUVM The VM handle.
374	* @param hMod The module to use.
375	* @param pGCPtrLogBuf Where to store the log buffer pointer on success.
376	* @param pcbLogBuf Where to store the size of the log buffer on success.
377	*/
378	static int dbgDiggerLinuxQueryAsciiLogBufferPtrs(PDBGDIGGERLINUX pThis, PUVM pUVM, RTDBGMOD hMod,
379	RTGCPTR pGCPtrLogBuf, uint32_t pcbLogBuf)
380	{
381	int rc = VINF_SUCCESS;
382
383	/**
384	* We disassemble emit_log_char to get at the log buffer address and size.
385	* This is used in case the symbols are not exported in kallsyms.
386	*
387	* This is what it typically looks like:
388	* vmlinux!emit_log_char:
389	* %00000000c01204a1 56 push esi
390	* %00000000c01204a2 8b 35 d0 1c 34 c0 mov esi, dword [0c0341cd0h]
391	* %00000000c01204a8 53 push ebx
392	* %00000000c01204a9 8b 1d 74 3b 3e c0 mov ebx, dword [0c03e3b74h]
393	* %00000000c01204af 8b 0d d8 1c 34 c0 mov ecx, dword [0c0341cd8h]
394	* %00000000c01204b5 8d 56 ff lea edx, [esi-001h]
395	* %00000000c01204b8 21 da and edx, ebx
396	* %00000000c01204ba 88 04 11 mov byte [ecx+edx], al
397	* %00000000c01204bd 8d 53 01 lea edx, [ebx+001h]
398	* %00000000c01204c0 89 d0 mov eax, edx
399	* [...]
400	*/
401	RTDBGSYMBOL SymInfo;
402	rc = RTDbgModSymbolByName(hMod, "emit_log_char", &SymInfo);
403	if (RT_SUCCESS(rc))
404	{
405	/*
406	* Do the diassembling. Disassemble until a ret instruction is encountered
407	* or a limit is reached (don't want to disassemble for too long as the getter
408	* should be short). Certain instructions found are ignored (push, nop, etc.).
409	*/
410	unsigned cInstrDisassembled = 0;
411	uint32_t offInstr = 0;
412	bool fRet = false;
413	DISSTATE DisState;
414	unsigned cAddressesUsed = 0;
415	struct { size_t cb; RTGCPTR GCPtrOrigSrc; } aAddresses[5];
416	RT_ZERO(DisState);
417	RT_ZERO(aAddresses);
418
419	do
420	{
421	DBGFADDRESS Addr;
422	RTGCPTR GCPtrCur = (RTGCPTR)SymInfo.Value + pThis->AddrKernelBase.FlatPtr + offInstr;
423	DBGFR3AddrFromFlat(pUVM, &Addr, GCPtrCur);
424
425	/* Prefetch the instruction. */
426	uint8_t abInstr[32];
427	rc = DBGFR3MemRead(pUVM, 0 /idCpu/, &Addr, &abInstr[0], sizeof(abInstr));
428	if (RT_SUCCESS(rc))
429	{
430	uint32_t cbInstr = 0;
431
432	rc = DISInstr(&abInstr[0], pThis->f64Bit ? DISCPUMODE_64BIT : DISCPUMODE_32BIT, &DisState, &cbInstr);
433	if (RT_SUCCESS(rc))
434	{
435	switch (DisState.pCurInstr->uOpcode)
436	{
437	case OP_PUSH:
438	case OP_POP:
439	case OP_NOP:
440	case OP_LEA:
441	case OP_AND:
442	case OP_CBW:
443	break;
444	case OP_RETN:
445	/* emit_log_char returned, abort disassembling. */
446	rc = VERR_NOT_FOUND;
447	fRet = true;
448	break;
449	case OP_MOV:
450	case OP_MOVSXD:
451	/*
452	* If a mov is encountered writing to memory with al (or dil for amd64) being the source the
453	* character is stored and we can infer the base address and size of the log buffer from
454	* the source addresses.
455	*/
456	if ( (DisState.Param2.fUse & DISUSE_REG_GEN8)
457	&& ( (DisState.Param2.Base.idxGenReg == DISGREG_AL && !pThis->f64Bit)
458	\|\| (DisState.Param2.Base.idxGenReg == DISGREG_DIL && pThis->f64Bit))
459	&& DISUSE_IS_EFFECTIVE_ADDR(DisState.Param1.fUse))
460	{
461	RTGCPTR GCPtrLogBuf = 0;
462	uint32_t cbLogBuf = 0;
463
464	/*
465	* We can stop disassembling now and inspect all registers, look for a valid kernel address first.
466	* Only one of the accessed registers should hold a valid kernel address.
467	* For the log size look for the biggest non kernel address.
468	*/
469	for (unsigned i = 0; i < cAddressesUsed; i++)
470	{
471	DBGFADDRESS AddrVal;
472	union { uint8_t abVal[8]; uint32_t u32Val; uint64_t u64Val; } Val;
473
474	rc = DBGFR3MemRead(pUVM, 0 /idCpu/,
475	DBGFR3AddrFromFlat(pUVM, &AddrVal, aAddresses[i].GCPtrOrigSrc),
476	&Val.abVal[0], aAddresses[i].cb);
477	if (RT_SUCCESS(rc))
478	{
479	if (pThis->f64Bit && aAddresses[i].cb == sizeof(uint64_t))
480	{
481	if (LNX64_VALID_ADDRESS(Val.u64Val))
482	{
483	if (GCPtrLogBuf == 0)
484	GCPtrLogBuf = Val.u64Val;
485	else
486	{
487	rc = VERR_NOT_FOUND;
488	break;
489	}
490	}
491	}
492	else
493	{
494	AssertMsgBreakStmt(aAddresses[i].cb == sizeof(uint32_t),
495	("Invalid value size\n"), rc = VERR_INVALID_STATE);
496
497	/* Might be a kernel address or a size indicator. */
498	if (!pThis->f64Bit && LNX32_VALID_ADDRESS(Val.u32Val))
499	{
500	if (GCPtrLogBuf == 0)
501	GCPtrLogBuf = Val.u32Val;
502	else
503	{
504	rc = VERR_NOT_FOUND;
505	break;
506	}
507	}
508	else
509	{
510	/*
511	* The highest value will be the log buffer because the other
512	* accessed variables are indexes into the buffer and hence
513	* always smaller than the size.
514	*/
515	if (cbLogBuf < Val.u32Val)
516	cbLogBuf = Val.u32Val;
517	}
518	}
519	}
520	}
521
522	if ( RT_SUCCESS(rc)
523	&& GCPtrLogBuf != 0
524	&& cbLogBuf != 0)
525	{
526	*pGCPtrLogBuf = GCPtrLogBuf;
527	*pcbLogBuf = cbLogBuf;
528	}
529	else if (RT_SUCCESS(rc))
530	rc = VERR_NOT_FOUND;
531
532	fRet = true;
533	break;
534	}
535	else
536	{
537	/*
538	* In case of a memory to register move store the destination register index and the
539	* source address in the relation table for later processing.
540	*/
541	if ( (DisState.Param1.fUse & (DISUSE_BASE \| DISUSE_REG_GEN32 \| DISUSE_REG_GEN64))
542	&& (DisState.Param2.cb == sizeof(uint32_t) \|\| DisState.Param2.cb == sizeof(uint64_t))
543	&& (DisState.Param2.fUse & (DISUSE_RIPDISPLACEMENT32\|DISUSE_DISPLACEMENT32\|DISUSE_DISPLACEMENT64)))
544	{
545	RTGCPTR GCPtrVal = 0;
546
547	if (DisState.Param2.fUse & DISUSE_RIPDISPLACEMENT32)
548	GCPtrVal = GCPtrCur + DisState.Param2.uDisp.i32 + cbInstr;
549	else if (DisState.Param2.fUse & DISUSE_DISPLACEMENT32)
550	GCPtrVal = (RTGCPTR)DisState.Param2.uDisp.u32;
551	else if (DisState.Param2.fUse & DISUSE_DISPLACEMENT64)
552	GCPtrVal = (RTGCPTR)DisState.Param2.uDisp.u64;
553	else
554	AssertMsgFailedBreakStmt(("Invalid displacement\n"), rc = VERR_INVALID_STATE);
555
556	if (cAddressesUsed < RT_ELEMENTS(aAddresses))
557	{
558	/* movsxd reads always 32bits. */
559	if (DisState.pCurInstr->uOpcode == OP_MOVSXD)
560	aAddresses[cAddressesUsed].cb = sizeof(uint32_t);
561	else
562	aAddresses[cAddressesUsed].cb = DisState.Param2.cb;
563	aAddresses[cAddressesUsed].GCPtrOrigSrc = GCPtrVal;
564	cAddressesUsed++;
565	}
566	else
567	{
568	rc = VERR_INVALID_PARAMETER;
569	break;
570	}
571	}
572	}
573	break;
574	default:
575	/* All other instructions will cause an error for now (playing safe here). */
576	rc = VERR_INVALID_PARAMETER;
577	break;
578	}
579	cInstrDisassembled++;
580	offInstr += cbInstr;
581	}
582	}
583	} while ( RT_SUCCESS(rc)
584	&& cInstrDisassembled < 20
585	&& !fRet);
586	}
587
588	return rc;
589	}
590
591	/**
592	* Try to get at the log buffer starting address and size by disassembling some exposed helpers.
593	*
594	* @returns VBox status code.
595	* @param pThis The Linux digger data.
596	* @param pUVM The VM handle.
597	* @param hMod The module to use.
598	* @param pGCPtrLogBuf Where to store the log buffer pointer on success.
599	* @param pcbLogBuf Where to store the size of the log buffer on success.
600	*/
601	static int dbgDiggerLinuxQueryLogBufferPtrs(PDBGDIGGERLINUX pThis, PUVM pUVM, RTDBGMOD hMod,
602	RTGCPTR pGCPtrLogBuf, uint32_t pcbLogBuf)
603	{
604	int rc = VINF_SUCCESS;
605
606	struct { void pvVar; uint32_t cbHost, cbGuest; const char pszSymbol; } aSymbols[] =
607	{
608	{ pGCPtrLogBuf, (uint32_t)sizeof(RTGCPTR), (uint32_t)(pThis->f64Bit ? sizeof(uint64_t) : sizeof(uint32_t)), "log_buf_addr_get" },
609	{ pcbLogBuf, (uint32_t)sizeof(uint32_t), (uint32_t)sizeof(uint32_t), "log_buf_len_get" }
610	};
611	for (uint32_t i = 0; i < RT_ELEMENTS(aSymbols) && RT_SUCCESS(rc); i++)
612	{
613	RT_BZERO(aSymbols[i].pvVar, aSymbols[i].cbHost);
614	Assert(aSymbols[i].cbHost >= aSymbols[i].cbGuest);
615	rc = dbgDiggerLinuxDisassembleSimpleGetter(pThis, pUVM, hMod, aSymbols[i].pszSymbol,
616	aSymbols[i].pvVar, aSymbols[i].cbGuest);
617	}
618
619	return rc;
620	}
621
622	/**
623	* Returns whether the log buffer is a simple ascii buffer or a record based implementation
624	* based on the kernel version found.
625	*
626	* @returns Flag whether the log buffer is the simple ascii buffer.
627	* @param pThis The Linux digger data.
628	* @param pUVM The user mode VM handle.
629	*/
630	static bool dbgDiggerLinuxLogBufferIsAsciiBuffer(PDBGDIGGERLINUX pThis, PUVM pUVM)
631	{
632	char szTmp[128];
633	char const *pszVer = &szTmp[sizeof(g_abLinuxVersion) - 1];
634
635	RT_ZERO(szTmp);
636	int rc = DBGFR3MemReadString(pUVM, 0, &pThis->AddrLinuxBanner, szTmp, sizeof(szTmp) - 1);
637	if ( RT_SUCCESS(rc)
638	&& RTStrVersionCompare(pszVer, "3.4") == -1)
639	return true;
640
641	return false;
642	}
643
644	/**
645	* Worker to get at the kernel log for pre 3.4 kernels where the log buffer was just a char buffer.
646	*
647	* @returns VBox status code.
648	* @param pThis The Linux digger data.
649	* @param pUVM The VM user mdoe handle.
650	* @param hMod The debug module handle.
651	* @param fFlags Flags reserved for future use, MBZ.
652	* @param cMessages The number of messages to retrieve, counting from the
653	* end of the log (i.e. like tail), use UINT32_MAX for all.
654	* @param pszBuf The output buffer.
655	* @param cbBuf The buffer size.
656	* @param pcbActual Where to store the number of bytes actually returned,
657	* including zero terminator. On VERR_BUFFER_OVERFLOW this
658	* holds the necessary buffer size. Optional.
659	*/
660	static int dbgDiggerLinuxLogBufferQueryAscii(PDBGDIGGERLINUX pThis, PUVM pUVM, RTDBGMOD hMod,
661	uint32_t fFlags, uint32_t cMessages,
662	char pszBuf, size_t cbBuf, size_t pcbActual)
663	{
664	RT_NOREF2(fFlags, cMessages);
665	int rc = VINF_SUCCESS;
666	RTGCPTR GCPtrLogBuf;
667	uint32_t cbLogBuf;
668
669	struct { void pvVar; size_t cbHost, cbGuest; const char pszSymbol; } aSymbols[] =
670	{
671	{ &GCPtrLogBuf, sizeof(GCPtrLogBuf), pThis->f64Bit ? sizeof(uint64_t) : sizeof(uint32_t), "log_buf" },
672	{ &cbLogBuf, sizeof(cbLogBuf), sizeof(cbLogBuf), "log_buf_len" },
673	};
674	for (uint32_t i = 0; i < RT_ELEMENTS(aSymbols); i++)
675	{
676	RTDBGSYMBOL SymInfo;
677	rc = RTDbgModSymbolByName(hMod, aSymbols[i].pszSymbol, &SymInfo);
678	if (RT_SUCCESS(rc))
679	{
680	RT_BZERO(aSymbols[i].pvVar, aSymbols[i].cbHost);
681	Assert(aSymbols[i].cbHost >= aSymbols[i].cbGuest);
682	DBGFADDRESS Addr;
683	rc = DBGFR3MemRead(pUVM, 0 /idCpu/,
684	DBGFR3AddrFromFlat(pUVM, &Addr, (RTGCPTR)SymInfo.Value + pThis->AddrKernelBase.FlatPtr),
685	aSymbols[i].pvVar, aSymbols[i].cbGuest);
686	if (RT_SUCCESS(rc))
687	continue;
688	Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: Reading '%s' at %RGv: %Rrc\n", aSymbols[i].pszSymbol, Addr.FlatPtr, rc));
689	}
690	else
691	Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: Error looking up '%s': %Rrc\n", aSymbols[i].pszSymbol, rc));
692	rc = VERR_NOT_FOUND;
693	break;
694	}
695
696	/*
697	* Some kernels don't expose the variables in kallsyms so we have to try disassemble
698	* some public helpers to get at the addresses.
699	*
700	* @todo: Maybe cache those values so we don't have to do the heavy work every time?
701	*/
702	if (rc == VERR_NOT_FOUND)
703	{
704	rc = dbgDiggerLinuxQueryAsciiLogBufferPtrs(pThis, pUVM, hMod, &GCPtrLogBuf, &cbLogBuf);
705	if (RT_FAILURE(rc))
706	return rc;
707	}
708
709	/*
710	* Check if the values make sense.
711	*/
712	if (pThis->f64Bit ? !LNX64_VALID_ADDRESS(GCPtrLogBuf) : !LNX32_VALID_ADDRESS(GCPtrLogBuf))
713	{
714	Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: 'log_buf' value %RGv is not valid.\n", GCPtrLogBuf));
715	return VERR_NOT_FOUND;
716	}
717	if ( cbLogBuf < 4096
718	\|\| !RT_IS_POWER_OF_TWO(cbLogBuf)
719	\|\| cbLogBuf > 16*_1M)
720	{
721	Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: 'log_buf_len' value %#x is not valid.\n", cbLogBuf));
722	return VERR_NOT_FOUND;
723	}
724
725	/*
726	* Read the whole log buffer.
727	*/
728	uint8_t pbLogBuf = (uint8_t )RTMemAlloc(cbLogBuf);
729	if (!pbLogBuf)
730	{
731	Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: Failed to allocate %#x bytes for log buffer\n", cbLogBuf));
732	return VERR_NO_MEMORY;
733	}
734	DBGFADDRESS Addr;
735	rc = DBGFR3MemRead(pUVM, 0 /idCpu/, DBGFR3AddrFromFlat(pUVM, &Addr, GCPtrLogBuf), pbLogBuf, cbLogBuf);
736	if (RT_FAILURE(rc))
737	{
738	Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: Error reading %#x bytes of log buffer at %RGv: %Rrc\n",
739	cbLogBuf, Addr.FlatPtr, rc));
740	RTMemFree(pbLogBuf);
741	return VERR_NOT_FOUND;
742	}
743
744	/** @todo Try to parse where the single messages start to make use of cMessages. */
745	size_t cchLength = RTStrNLen((const char *)pbLogBuf, cbLogBuf);
746	memcpy(&pszBuf[0], pbLogBuf, RT_MIN(cbBuf, cchLength));
747
748	/* Done with the buffer. */
749	RTMemFree(pbLogBuf);
750
751	/* Set return size value. */
752	if (pcbActual)
753	*pcbActual = RT_MIN(cbBuf, cchLength);
754
755	return cbBuf <= cchLength ? VERR_BUFFER_OVERFLOW : VINF_SUCCESS;
756	}
757
758	/**
759	* Worker to get at the kernel log for post 3.4 kernels where the log buffer contains records.
760	*
761	* @returns VBox status code.
762	* @param pThis The Linux digger data.
763	* @param pUVM The VM user mdoe handle.
764	* @param hMod The debug module handle.
765	* @param fFlags Flags reserved for future use, MBZ.
766	* @param cMessages The number of messages to retrieve, counting from the
767	* end of the log (i.e. like tail), use UINT32_MAX for all.
768	* @param pszBuf The output buffer.
769	* @param cbBuf The buffer size.
770	* @param pcbActual Where to store the number of bytes actually returned,
771	* including zero terminator. On VERR_BUFFER_OVERFLOW this
772	* holds the necessary buffer size. Optional.
773	*/
774	static int dbgDiggerLinuxLogBufferQueryRecords(PDBGDIGGERLINUX pThis, PUVM pUVM, RTDBGMOD hMod,
775	uint32_t fFlags, uint32_t cMessages,
776	char pszBuf, size_t cbBuf, size_t pcbActual)
777	{
778	RT_NOREF1(fFlags);
779	int rc = VINF_SUCCESS;
780	RTGCPTR GCPtrLogBuf;
781	uint32_t cbLogBuf;
782	uint32_t idxFirst;
783	uint32_t idxNext;
784
785	struct { void pvVar; size_t cbHost, cbGuest; const char pszSymbol; } aSymbols[] =
786	{
787	{ &GCPtrLogBuf, sizeof(GCPtrLogBuf), pThis->f64Bit ? sizeof(uint64_t) : sizeof(uint32_t), "log_buf" },
788	{ &cbLogBuf, sizeof(cbLogBuf), sizeof(cbLogBuf), "log_buf_len" },
789	{ &idxFirst, sizeof(idxFirst), sizeof(idxFirst), "log_first_idx" },
790	{ &idxNext, sizeof(idxNext), sizeof(idxNext), "log_next_idx" },
791	};
792	for (uint32_t i = 0; i < RT_ELEMENTS(aSymbols); i++)
793	{
794	RTDBGSYMBOL SymInfo;
795	rc = RTDbgModSymbolByName(hMod, aSymbols[i].pszSymbol, &SymInfo);
796	if (RT_SUCCESS(rc))
797	{
798	RT_BZERO(aSymbols[i].pvVar, aSymbols[i].cbHost);
799	Assert(aSymbols[i].cbHost >= aSymbols[i].cbGuest);
800	DBGFADDRESS Addr;
801	rc = DBGFR3MemRead(pUVM, 0 /idCpu/,
802	DBGFR3AddrFromFlat(pUVM, &Addr, (RTGCPTR)SymInfo.Value + pThis->AddrKernelBase.FlatPtr),
803	aSymbols[i].pvVar, aSymbols[i].cbGuest);
804	if (RT_SUCCESS(rc))
805	continue;
806	Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: Reading '%s' at %RGv: %Rrc\n", aSymbols[i].pszSymbol, Addr.FlatPtr, rc));
807	}
808	else
809	Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: Error looking up '%s': %Rrc\n", aSymbols[i].pszSymbol, rc));
810	rc = VERR_NOT_FOUND;
811	break;
812	}
813
814	/*
815	* Some kernels don't expose the variables in kallsyms so we have to try disassemble
816	* some public helpers to get at the addresses.
817	*
818	* @todo: Maybe cache those values so we don't have to do the heavy work every time?
819	*/
820	if (rc == VERR_NOT_FOUND)
821	{
822	idxFirst = 0;
823	idxNext = 0;
824	rc = dbgDiggerLinuxQueryLogBufferPtrs(pThis, pUVM, hMod, &GCPtrLogBuf, &cbLogBuf);
825	if (RT_FAILURE(rc))
826	return rc;
827	}
828
829	/*
830	* Check if the values make sense.
831	*/
832	if (pThis->f64Bit ? !LNX64_VALID_ADDRESS(GCPtrLogBuf) : !LNX32_VALID_ADDRESS(GCPtrLogBuf))
833	{
834	Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: 'log_buf' value %RGv is not valid.\n", GCPtrLogBuf));
835	return VERR_NOT_FOUND;
836	}
837	if ( cbLogBuf < 4096
838	\|\| !RT_IS_POWER_OF_TWO(cbLogBuf)
839	\|\| cbLogBuf > 16*_1M)
840	{
841	Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: 'log_buf_len' value %#x is not valid.\n", cbLogBuf));
842	return VERR_NOT_FOUND;
843	}
844	uint32_t const cbLogAlign = 4;
845	if ( idxFirst > cbLogBuf - sizeof(LNXPRINTKHDR)
846	\|\| (idxFirst & (cbLogAlign - 1)) != 0)
847	{
848	Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: 'log_first_idx' value %#x is not valid.\n", idxFirst));
849	return VERR_NOT_FOUND;
850	}
851	if ( idxNext > cbLogBuf - sizeof(LNXPRINTKHDR)
852	\|\| (idxNext & (cbLogAlign - 1)) != 0)
853	{
854	Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: 'log_next_idx' value %#x is not valid.\n", idxNext));
855	return VERR_NOT_FOUND;
856	}
857
858	/*
859	* Read the whole log buffer.
860	*/
861	uint8_t pbLogBuf = (uint8_t )RTMemAlloc(cbLogBuf);
862	if (!pbLogBuf)
863	{
864	Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: Failed to allocate %#x bytes for log buffer\n", cbLogBuf));
865	return VERR_NO_MEMORY;
866	}
867	DBGFADDRESS Addr;
868	rc = DBGFR3MemRead(pUVM, 0 /idCpu/, DBGFR3AddrFromFlat(pUVM, &Addr, GCPtrLogBuf), pbLogBuf, cbLogBuf);
869	if (RT_FAILURE(rc))
870	{
871	Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: Error reading %#x bytes of log buffer at %RGv: %Rrc\n",
872	cbLogBuf, Addr.FlatPtr, rc));
873	RTMemFree(pbLogBuf);
874	return VERR_NOT_FOUND;
875	}
876
877	/*
878	* Count the messages in the buffer while doing some basic validation.
879	*/
880	uint32_t const cbUsed = idxFirst == idxNext ? cbLogBuf /* could be empty... */
881	: idxFirst < idxNext ? idxNext - idxFirst : cbLogBuf - idxFirst + idxNext;
882	uint32_t cbLeft = cbUsed;
883	uint32_t offCur = idxFirst;
884	uint32_t cLogMsgs = 0;
885
886	while (cbLeft > 0)
887	{
888	PCLNXPRINTKHDR pHdr = (PCLNXPRINTKHDR)&pbLogBuf[offCur];
889	if (!pHdr->cbTotal)
890	{
891	/* Wrap around packet, most likely... */
892	if (cbLogBuf - offCur >= cbLeft)
893	break;
894	offCur = 0;
895	pHdr = (PCLNXPRINTKHDR)&pbLogBuf[offCur];
896	}
897	if (RT_UNLIKELY( pHdr->cbTotal > cbLogBuf - sizeof(*pHdr) - offCur
898	\|\| pHdr->cbTotal > cbLeft
899	\|\| (pHdr->cbTotal & (cbLogAlign - 1)) != 0
900	\|\| pHdr->cbTotal < (uint32_t)pHdr->cbText + (uint32_t)pHdr->cbDict + sizeof(*pHdr) ))
901	{
902	Log(("dbgDiggerLinuxIDmsg_QueryKernelLog: Invalid printk_log record at %#x: cbTotal=%#x cbText=%#x cbDict=%#x cbLogBuf=%#x cbLeft=%#x\n",
903	offCur, pHdr->cbTotal, pHdr->cbText, pHdr->cbDict, cbLogBuf, cbLeft));
904	rc = VERR_INVALID_STATE;
905	break;
906	}
907
908	if (pHdr->cbText > 0)
909	cLogMsgs++;
910
911	/* next */
912	offCur += pHdr->cbTotal;
913	cbLeft -= pHdr->cbTotal;
914	}
915	if (RT_FAILURE(rc))
916	{
917	RTMemFree(pbLogBuf);
918	return rc;
919	}
920
921	/*
922	* Copy the messages into the output buffer.
923	*/
924	offCur = idxFirst;
925	cbLeft = cbUsed;
926
927	/* Skip messages that the caller doesn't want. */
928	if (cMessages < cLogMsgs)
929	{
930	uint32_t cToSkip = cLogMsgs - cMessages;
931	while (cToSkip > 0)
932	{
933	PCLNXPRINTKHDR pHdr = (PCLNXPRINTKHDR)&pbLogBuf[offCur];
934	if (!pHdr->cbTotal)
935	{
936	offCur = 0;
937	pHdr = (PCLNXPRINTKHDR)&pbLogBuf[offCur];
938	}
939	if (pHdr->cbText > 0)
940	cToSkip--;
941
942	/* next */
943	offCur += pHdr->cbTotal;
944	cbLeft -= pHdr->cbTotal;
945	}
946	}
947
948	/* Now copy the messages. */
949	size_t offDst = 0;
950	while (cbLeft > 0)
951	{
952	PCLNXPRINTKHDR pHdr = (PCLNXPRINTKHDR)&pbLogBuf[offCur];
953	if (!pHdr->cbTotal)
954	{
955	if (cbLogBuf - offCur >= cbLeft)
956	break;
957	offCur = 0;
958	pHdr = (PCLNXPRINTKHDR)&pbLogBuf[offCur];
959	}
960
961	if (pHdr->cbText > 0)
962	{
963	char pchText = (char )(pHdr + 1);
964	size_t cchText = RTStrNLen(pchText, pHdr->cbText);
965	if (offDst + cchText < cbBuf)
966	{
967	memcpy(&pszBuf[offDst], pHdr + 1, cchText);
968	pszBuf[offDst + cchText] = '\n';
969	}
970	else if (offDst < cbBuf)
971	memcpy(&pszBuf[offDst], pHdr + 1, cbBuf - offDst);
972	offDst += cchText + 1;
973	}
974
975	/* next */
976	offCur += pHdr->cbTotal;
977	cbLeft -= pHdr->cbTotal;
978	}
979
980	/* Done with the buffer. */
981	RTMemFree(pbLogBuf);
982
983	/* Make sure we've reserved a char for the terminator. */
984	if (!offDst)
985	offDst = 1;
986
987	/* Set return size value. */
988	if (pcbActual)
989	*pcbActual = offDst;
990
991	if (offDst <= cbBuf)
992	return VINF_SUCCESS;
993	else
994	return VERR_BUFFER_OVERFLOW;
995	}
996
997	/**
998	* @interface_method_impl{DBGFOSIDMESG,pfnQueryKernelLog}
999	*/
1000	static DECLCALLBACK(int) dbgDiggerLinuxIDmsg_QueryKernelLog(PDBGFOSIDMESG pThis, PUVM pUVM, uint32_t fFlags, uint32_t cMessages,
1001	char pszBuf, size_t cbBuf, size_t pcbActual)
1002	{
1003	PDBGDIGGERLINUX pData = RT_FROM_MEMBER(pThis, DBGDIGGERLINUX, IDmesg);
1004
1005	if (cMessages < 1)
1006	return VERR_INVALID_PARAMETER;
1007
1008	/*
1009	* Resolve the symbols we need and read their values.
1010	*/
1011	RTDBGAS hAs = DBGFR3AsResolveAndRetain(pUVM, DBGF_AS_KERNEL);
1012	RTDBGMOD hMod;
1013	int rc = RTDbgAsModuleByName(hAs, "vmlinux", 0, &hMod);
1014	if (RT_FAILURE(rc))
1015	return VERR_NOT_FOUND;
1016	RTDbgAsRelease(hAs);
1017
1018	size_t cbActual;
1019	/*
1020	* Check whether the kernel log buffer is a simple char buffer or the newer
1021	* record based implementation.
1022	* The record based implementation was presumably introduced with kernel 3.4,
1023	* see: http://thread.gmane.org/gmane.linux.kernel/1284184
1024	*/
1025	if (dbgDiggerLinuxLogBufferIsAsciiBuffer(pData, pUVM))
1026	rc = dbgDiggerLinuxLogBufferQueryAscii(pData, pUVM, hMod, fFlags, cMessages, pszBuf, cbBuf, &cbActual);
1027	else
1028	rc = dbgDiggerLinuxLogBufferQueryRecords(pData, pUVM, hMod, fFlags, cMessages, pszBuf, cbBuf, &cbActual);
1029
1030	/* Release the module in any case. */
1031	RTDbgModRelease(hMod);
1032
1033	if (RT_FAILURE(rc) && rc != VERR_BUFFER_OVERFLOW)
1034	return rc;
1035
1036	if (pcbActual)
1037	*pcbActual = cbActual;
1038
1039	/*
1040	* All VBox strings are UTF-8 and bad things may in theory happen if we
1041	* pass bad UTF-8 to code which assumes it's all valid. So, we enforce
1042	* UTF-8 upon the guest kernel messages here even if they (probably) have
1043	* no defined code set in reality.
1044	*/
1045	if ( RT_SUCCESS(rc)
1046	&& cbActual <= cbBuf)
1047	{
1048	pszBuf[cbActual - 1] = '\0';
1049	RTStrPurgeEncoding(pszBuf);
1050	return VINF_SUCCESS;
1051	}
1052
1053	if (cbBuf)
1054	{
1055	pszBuf[cbBuf - 1] = '\0';
1056	RTStrPurgeEncoding(pszBuf);
1057	}
1058	return VERR_BUFFER_OVERFLOW;
1059	}
1060
1061
1062	/**
1063	* Worker destroying the config database.
1064	*/
1065	static DECLCALLBACK(int) dbgDiggerLinuxCfgDbDestroyWorker(PRTSTRSPACECORE pStr, void *pvUser)
1066	{
1067	PDBGDIGGERLINUXCFGITEM pCfgItem = (PDBGDIGGERLINUXCFGITEM)pStr;
1068	RTStrFree((char *)pCfgItem->Core.pszString);
1069	RTMemFree(pCfgItem);
1070	NOREF(pvUser);
1071	return 0;
1072	}
1073
1074
1075	/**
1076	* Destroy the config database.
1077	*
1078	* @returns nothing.
1079	* @param pThis The Linux digger data.
1080	*/
1081	static void dbgDiggerLinuxCfgDbDestroy(PDBGDIGGERLINUX pThis)
1082	{
1083	RTStrSpaceDestroy(&pThis->hCfgDb, dbgDiggerLinuxCfgDbDestroyWorker, NULL);
1084	}
1085
1086
1087	/**
1088	* @copydoc DBGFOSREG::pfnQueryInterface
1089	*/
1090	static DECLCALLBACK(void ) dbgDiggerLinuxQueryInterface(PUVM pUVM, void pvData, DBGFOSINTERFACE enmIf)
1091	{
1092	RT_NOREF1(pUVM);
1093	PDBGDIGGERLINUX pThis = (PDBGDIGGERLINUX)pvData;
1094	switch (enmIf)
1095	{
1096	case DBGFOSINTERFACE_DMESG:
1097	return &pThis->IDmesg;
1098
1099	default:
1100	return NULL;
1101	}
1102	}
1103
1104
1105	/**
1106	* @copydoc DBGFOSREG::pfnQueryVersion
1107	*/
1108	static DECLCALLBACK(int) dbgDiggerLinuxQueryVersion(PUVM pUVM, void pvData, char pszVersion, size_t cchVersion)
1109	{
1110	PDBGDIGGERLINUX pThis = (PDBGDIGGERLINUX)pvData;
1111	Assert(pThis->fValid);
1112
1113	/*
1114	* It's all in the linux banner.
1115	*/
1116	int rc = DBGFR3MemReadString(pUVM, 0, &pThis->AddrLinuxBanner, pszVersion, cchVersion);
1117	if (RT_SUCCESS(rc))
1118	{
1119	char *pszEnd = RTStrEnd(pszVersion, cchVersion);
1120	AssertReturn(pszEnd, VERR_BUFFER_OVERFLOW);
1121	while ( pszEnd > pszVersion
1122	&& RT_C_IS_SPACE(pszEnd[-1]))
1123	pszEnd--;
1124	*pszEnd = '\0';
1125	}
1126	else
1127	RTStrPrintf(pszVersion, cchVersion, "DBGFR3MemRead -> %Rrc", rc);
1128
1129	return rc;
1130	}
1131
1132
1133	/**
1134	* @copydoc DBGFOSREG::pfnTerm
1135	*/
1136	static DECLCALLBACK(void) dbgDiggerLinuxTerm(PUVM pUVM, void *pvData)
1137	{
1138	RT_NOREF1(pUVM);
1139	PDBGDIGGERLINUX pThis = (PDBGDIGGERLINUX)pvData;
1140	Assert(pThis->fValid);
1141
1142	dbgDiggerLinuxCfgDbDestroy(pThis);
1143	pThis->fValid = false;
1144	}
1145
1146
1147	/**
1148	* @copydoc DBGFOSREG::pfnRefresh
1149	*/
1150	static DECLCALLBACK(int) dbgDiggerLinuxRefresh(PUVM pUVM, void *pvData)
1151	{
1152	PDBGDIGGERLINUX pThis = (PDBGDIGGERLINUX)pvData;
1153	NOREF(pThis);
1154	Assert(pThis->fValid);
1155
1156	/*
1157	* For now we'll flush and reload everything.
1158	*/
1159	dbgDiggerLinuxTerm(pUVM, pvData);
1160	return dbgDiggerLinuxInit(pUVM, pvData);
1161	}
1162
1163
1164	/**
1165	* Worker for dbgDiggerLinuxFindStartOfNamesAndSymbolCount that update the
1166	* digger data.
1167	*
1168	* @returns VINF_SUCCESS.
1169	* @param pThis The Linux digger data to update.
1170	* @param pAddrKernelNames The kallsyms_names address.
1171	* @param cKernelSymbols The number of kernel symbol.
1172	* @param cbAddress The guest address size.
1173	*/
1174	static int dbgDiggerLinuxFoundStartOfNames(PDBGDIGGERLINUX pThis, PCDBGFADDRESS pAddrKernelNames,
1175	uint32_t cKernelSymbols, uint32_t cbAddress)
1176	{
1177	pThis->cKernelSymbols = cKernelSymbols;
1178	pThis->AddrKernelNames = *pAddrKernelNames;
1179	pThis->AddrKernelAddresses = *pAddrKernelNames;
1180	uint32_t cbSymbolsSkip = (pThis->fRelKrnlAddr ? 2 : 1) * cbAddress; /* Relative addressing introduces kallsyms_relative_base. */
1181	uint32_t cbOffsets = pThis->fRelKrnlAddr ? sizeof(int32_t) : cbAddress; /* Offsets are always 32bits wide for relative addressing. */
1182	uint32_t cbAlign = 0;
1183
1184	/*
1185	* If the number of symbols is odd there is padding to align the following guest pointer
1186	* sized data properly on 64bit systems with relative addressing.
1187	*/
1188	if ( pThis->fRelKrnlAddr
1189	&& pThis->f64Bit
1190	&& (pThis->cKernelSymbols & 1))
1191	cbAlign = sizeof(int32_t);
1192	DBGFR3AddrSub(&pThis->AddrKernelAddresses, cKernelSymbols * cbOffsets + cbSymbolsSkip + cbAlign);
1193
1194	Log(("dbgDiggerLinuxFoundStartOfNames: AddrKernelAddresses=%RGv\n"
1195	"dbgDiggerLinuxFoundStartOfNames: cKernelSymbols=%#x (at %RGv)\n"
1196	"dbgDiggerLinuxFoundStartOfNames: AddrKernelName=%RGv\n",
1197	pThis->AddrKernelAddresses.FlatPtr,
1198	pThis->cKernelSymbols, pThis->AddrKernelNames.FlatPtr - cbAddress,
1199	pThis->AddrKernelNames.FlatPtr));
1200	return VINF_SUCCESS;
1201	}
1202
1203
1204	/**
1205	* Tries to find the address of the kallsyms_names, kallsyms_num_syms and
1206	* kallsyms_addresses symbols.
1207	*
1208	* The kallsyms_num_syms is read and stored in pThis->cKernelSymbols, while the
1209	* addresses of the other two are stored as pThis->AddrKernelNames and
1210	* pThis->AddrKernelAddresses.
1211	*
1212	* @returns VBox status code, success indicating that all three variables have
1213	* been found and taken down.
1214	* @param pUVM The user mode VM handle.
1215	* @param pThis The Linux digger data.
1216	* @param pHitAddr An address we think is inside kallsyms_names.
1217	*/
1218	static int dbgDiggerLinuxFindStartOfNamesAndSymbolCount(PUVM pUVM, PDBGDIGGERLINUX pThis, PCDBGFADDRESS pHitAddr)
1219	{
1220	/*
1221	* Search backwards in chunks.
1222	*/
1223	union
1224	{
1225	uint8_t ab[0x1000];
1226	uint32_t au32[0x1000 / sizeof(uint32_t)];
1227	uint64_t au64[0x1000 / sizeof(uint64_t)];
1228	} uBuf;
1229	uint32_t cbLeft = LNX_MAX_KALLSYMS_NAMES_SIZE;
1230	uint32_t cbBuf = pHitAddr->FlatPtr & (sizeof(uBuf) - 1);
1231	DBGFADDRESS CurAddr = *pHitAddr;
1232	DBGFR3AddrSub(&CurAddr, cbBuf);
1233	cbBuf += sizeof(uint64_t) - 1; /* In case our kobj hit is in the first 4/8 bytes. */
1234	for (;;)
1235	{
1236	int rc = DBGFR3MemRead(pUVM, 0 /idCpu/, &CurAddr, &uBuf, sizeof(uBuf));
1237	if (RT_FAILURE(rc))
1238	return rc;
1239
1240	/*
1241	* Since Linux 4.6 there are two different methods to store the kallsyms addresses
1242	* in the image.
1243	*
1244	* The first and longer existing method is to store the absolute addresses in an
1245	* array starting at kallsyms_addresses followed by a field which stores the number
1246	* of kernel symbols called kallsyms_num_syms.
1247	* The newer method is to use offsets stored in kallsyms_offsets and have a base pointer
1248	* to relate the offsets to called kallsyms_relative_base. One entry in kallsyms_offsets is
1249	* always 32bit wide regardless of the guest pointer size (this halves the table on 64bit
1250	* systems) but means more work for us for the 64bit case.
1251	*
1252	* When absolute addresses are used the following assumptions hold:
1253	*
1254	* We assume that the three symbols are aligned on guest pointer boundary.
1255	*
1256	* The boundary between the two tables should be noticable as the number
1257	* is unlikely to be more than 16 millions, there will be at least one zero
1258	* byte where it is, 64-bit will have 5 zero bytes. Zero bytes aren't all
1259	* that common in the kallsyms_names table.
1260	*
1261	* Also the kallsyms_names table starts with a length byte, which means
1262	* we're likely to see a byte in the range 1..31.
1263	*
1264	* The kallsyms_addresses are mostly sorted (except for the start where the
1265	* absolute symbols are), so we'll spot a bunch of kernel addresses
1266	* immediately preceeding the kallsyms_num_syms field.
1267	*
1268	* Lazy bird: If kallsyms_num_syms is on a buffer boundrary, we skip
1269	* the check for kernel addresses preceeding it.
1270	*
1271	* For relative offsets most of the assumptions from above are true too
1272	* except that we have to distinguish between the relative base address and the offsets.
1273	* Every observed kernel has a valid kernel address fo the relative base and kallsyms_relative_base
1274	* always comes before kallsyms_num_syms and is aligned on a guest pointer boundary.
1275	* Offsets are stored before kallsyms_relative_base and don't contain valid kernel addresses.
1276	*
1277	* To distinguish between absolute and relative offsetting we check the data before a candidate
1278	* for kallsyms_num_syms. If all entries before the kallsyms_num_syms candidate are valid kernel
1279	* addresses absolute addresses are assumed. If this is not the case but the first entry before
1280	* kallsyms_num_syms is a valid kernel address we check whether the data before and the possible
1281	* relative base form a valid kernel address and assume relative offsets.
1282	*/
1283	if (pThis->f64Bit)
1284	{
1285	uint32_t i = cbBuf / sizeof(uint64_t);
1286	while (i-- > 0)
1287	if ( uBuf.au64[i] <= LNX_MAX_KALLSYMS_SYMBOLS
1288	&& uBuf.au64[i] >= LNX_MIN_KALLSYMS_SYMBOLS)
1289	{
1290	uint8_t pb = (uint8_t )&uBuf.au64[i + 1];
1291	if ( pb[0] <= LNX_MAX_KALLSYMS_ENC_LENGTH
1292	&& pb[0] >= LNX_MIN_KALLSYMS_ENC_LENGTH)
1293	{
1294	/*
1295	* Check whether we have a valid kernel address and try to distinguish
1296	* whether the kernel uses relative offsetting or absolute addresses.
1297	*/
1298	if ( (i >= 1 && LNX64_VALID_ADDRESS(uBuf.au64[i - 1]))
1299	&& (i >= 2 && !LNX64_VALID_ADDRESS(uBuf.au64[i - 2]))
1300	&& (i >= 3 && !LNX64_VALID_ADDRESS(uBuf.au64[i - 3])))
1301	{
1302	RTGCUINTPTR uKrnlRelBase = uBuf.au64[i - 1];
1303	DBGFADDRESS RelAddr = CurAddr;
1304	int32_t aiRelOff[3];
1305	rc = DBGFR3MemRead(pUVM, 0 /idCpu/, DBGFR3AddrAdd(&RelAddr, (i - 1) * sizeof(uint64_t) - sizeof(aiRelOff)),
1306	&aiRelOff[0], sizeof(aiRelOff));
1307	if ( RT_SUCCESS(rc)
1308	&& LNX64_VALID_ADDRESS(uKrnlRelBase + aiRelOff[0])
1309	&& LNX64_VALID_ADDRESS(uKrnlRelBase + aiRelOff[1])
1310	&& LNX64_VALID_ADDRESS(uKrnlRelBase + aiRelOff[2]))
1311	{
1312	Log(("dbgDiggerLinuxFindStartOfNamesAndSymbolCount: relative base %RGv (at %RGv)\n",
1313	uKrnlRelBase, CurAddr.FlatPtr + (i - 1) * sizeof(uint64_t)));
1314	pThis->fRelKrnlAddr = true;
1315	pThis->uKernelRelativeBase = uKrnlRelBase;
1316	return dbgDiggerLinuxFoundStartOfNames(pThis,
1317	DBGFR3AddrAdd(&CurAddr, (i + 1) * sizeof(uint64_t)),
1318	(uint32_t)uBuf.au64[i], sizeof(uint64_t));
1319	}
1320	}
1321
1322	if ( (i <= 0 \|\| LNX64_VALID_ADDRESS(uBuf.au64[i - 1]))
1323	&& (i <= 1 \|\| LNX64_VALID_ADDRESS(uBuf.au64[i - 2]))
1324	&& (i <= 2 \|\| LNX64_VALID_ADDRESS(uBuf.au64[i - 3])))
1325	return dbgDiggerLinuxFoundStartOfNames(pThis,
1326	DBGFR3AddrAdd(&CurAddr, (i + 1) * sizeof(uint64_t)),
1327	(uint32_t)uBuf.au64[i], sizeof(uint64_t));
1328	}
1329	}
1330	}
1331	else
1332	{
1333	uint32_t i = cbBuf / sizeof(uint32_t);
1334	while (i-- > 0)
1335	if ( uBuf.au32[i] <= LNX_MAX_KALLSYMS_SYMBOLS
1336	&& uBuf.au32[i] >= LNX_MIN_KALLSYMS_SYMBOLS)
1337	{
1338	uint8_t pb = (uint8_t )&uBuf.au32[i + 1];
1339	if ( pb[0] <= LNX_MAX_KALLSYMS_ENC_LENGTH
1340	&& pb[0] >= LNX_MIN_KALLSYMS_ENC_LENGTH)
1341	{
1342	/* Check for relative base addressing. */
1343	if (i >= 1 && LNX32_VALID_ADDRESS(uBuf.au32[i - 1]))
1344	{
1345	RTGCUINTPTR uKrnlRelBase = uBuf.au32[i - 1];
1346	if ( (i <= 1 \|\| LNX32_VALID_ADDRESS(uKrnlRelBase + uBuf.au32[i - 2]))
1347	&& (i <= 2 \|\| LNX32_VALID_ADDRESS(uKrnlRelBase + uBuf.au32[i - 3])))
1348	{
1349	Log(("dbgDiggerLinuxFindStartOfNamesAndSymbolCount: relative base %RGv (at %RGv)\n",
1350	uKrnlRelBase, CurAddr.FlatPtr + (i - 1) * sizeof(uint32_t)));
1351	pThis->fRelKrnlAddr = true;
1352	pThis->uKernelRelativeBase = uKrnlRelBase;
1353	return dbgDiggerLinuxFoundStartOfNames(pThis,
1354	DBGFR3AddrAdd(&CurAddr, (i + 1) * sizeof(uint32_t)),
1355	uBuf.au32[i], sizeof(uint32_t));
1356	}
1357	}
1358
1359	if ( (i <= 0 \|\| LNX32_VALID_ADDRESS(uBuf.au32[i - 1]))
1360	&& (i <= 1 \|\| LNX32_VALID_ADDRESS(uBuf.au32[i - 2]))
1361	&& (i <= 2 \|\| LNX32_VALID_ADDRESS(uBuf.au32[i - 3])))
1362	return dbgDiggerLinuxFoundStartOfNames(pThis,
1363	DBGFR3AddrAdd(&CurAddr, (i + 1) * sizeof(uint32_t)),
1364	uBuf.au32[i], sizeof(uint32_t));
1365	}
1366	}
1367	}
1368
1369	/*
1370	* Advance
1371	*/
1372	if (RT_UNLIKELY(cbLeft <= sizeof(uBuf)))
1373	{
1374	Log(("dbgDiggerLinuxFindStartOfNamesAndSymbolCount: failed (pHitAddr=%RGv)\n", pHitAddr->FlatPtr));
1375	return VERR_NOT_FOUND;
1376	}
1377	cbLeft -= sizeof(uBuf);
1378	DBGFR3AddrSub(&CurAddr, sizeof(uBuf));
1379	cbBuf = sizeof(uBuf);
1380	}
1381	}
1382
1383
1384	/**
1385	* Worker for dbgDiggerLinuxFindEndNames that records the findings.
1386	*
1387	* @returns VINF_SUCCESS
1388	* @param pThis The linux digger data to update.
1389	* @param pAddrMarkers The address of the marker (kallsyms_markers).
1390	* @param cbMarkerEntry The size of a marker entry (32-bit or 64-bit).
1391	*/
1392	static int dbgDiggerLinuxFoundMarkers(PDBGDIGGERLINUX pThis, PCDBGFADDRESS pAddrMarkers, uint32_t cbMarkerEntry)
1393	{
1394	pThis->cbKernelNames = pAddrMarkers->FlatPtr - pThis->AddrKernelNames.FlatPtr;
1395	pThis->AddrKernelNameMarkers = *pAddrMarkers;
1396	pThis->cKernelNameMarkers = RT_ALIGN_32(pThis->cKernelSymbols, 256) / 256;
1397	pThis->AddrKernelTokenTable = *pAddrMarkers;
1398	DBGFR3AddrAdd(&pThis->AddrKernelTokenTable, pThis->cKernelNameMarkers * cbMarkerEntry);
1399
1400	Log(("dbgDiggerLinuxFoundMarkers: AddrKernelNames=%RGv cbKernelNames=%#x\n"
1401	"dbgDiggerLinuxFoundMarkers: AddrKernelNameMarkers=%RGv cKernelNameMarkers=%#x\n"
1402	"dbgDiggerLinuxFoundMarkers: AddrKernelTokenTable=%RGv\n",
1403	pThis->AddrKernelNames.FlatPtr, pThis->cbKernelNames,
1404	pThis->AddrKernelNameMarkers.FlatPtr, pThis->cKernelNameMarkers,
1405	pThis->AddrKernelTokenTable.FlatPtr));
1406	return VINF_SUCCESS;
1407	}
1408
1409
1410	/**
1411	* Tries to find the end of kallsyms_names and thereby the start of
1412	* kallsyms_markers and kallsyms_token_table.
1413	*
1414	* The kallsyms_names size is stored in pThis->cbKernelNames, the addresses of
1415	* the two other symbols in pThis->AddrKernelNameMarkers and
1416	* pThis->AddrKernelTokenTable. The number of marker entries is stored in
1417	* pThis->cKernelNameMarkers.
1418	*
1419	* @returns VBox status code, success indicating that all three variables have
1420	* been found and taken down.
1421	* @param pUVM The user mode VM handle.
1422	* @param pThis The Linux digger data.
1423	* @param pHitAddr An address we think is inside kallsyms_names.
1424	*/
1425	static int dbgDiggerLinuxFindEndOfNamesAndMore(PUVM pUVM, PDBGDIGGERLINUX pThis, PCDBGFADDRESS pHitAddr)
1426	{
1427	/*
1428	* Search forward in chunks.
1429	*/
1430	union
1431	{
1432	uint8_t ab[0x1000];
1433	uint32_t au32[0x1000 / sizeof(uint32_t)];
1434	uint64_t au64[0x1000 / sizeof(uint64_t)];
1435	} uBuf;
1436	bool fPendingZeroHit = false;
1437	uint32_t cbLeft = LNX_MAX_KALLSYMS_NAMES_SIZE + sizeof(uBuf);
1438	uint32_t offBuf = pHitAddr->FlatPtr & (sizeof(uBuf) - 1);
1439	DBGFADDRESS CurAddr = *pHitAddr;
1440	DBGFR3AddrSub(&CurAddr, offBuf);
1441	for (;;)
1442	{
1443	int rc = DBGFR3MemRead(pUVM, 0 /idCpu/, &CurAddr, &uBuf, sizeof(uBuf));
1444	if (RT_FAILURE(rc))
1445	return rc;
1446
1447	/*
1448	* The kallsyms_names table is followed by kallsyms_markers we assume,
1449	* using sizeof(unsigned long) alignment like the preceeding symbols.
1450	*
1451	* The kallsyms_markers table has entried sizeof(unsigned long) and
1452	* contains offsets into kallsyms_names. The kallsyms_markers used to
1453	* index kallsyms_names and reduce seek time when looking up the name
1454	* of an address/symbol. Each entry in kallsyms_markers covers 256
1455	* symbol names.
1456	*
1457	* Because of this, the first entry is always zero and all the entries
1458	* are ascending. It also follows that the size of the table can be
1459	* calculated from kallsyms_num_syms.
1460	*
1461	* Note! We could also have walked kallsyms_names by skipping
1462	* kallsyms_num_syms names, but this is faster and we will
1463	* validate the encoded names later.
1464	*/
1465	if (pThis->f64Bit)
1466	{
1467	if ( RT_UNLIKELY(fPendingZeroHit)
1468	&& uBuf.au64[0] >= (LNX_MIN_KALLSYMS_ENC_LENGTH + 1) * 256
1469	&& uBuf.au64[0] <= (LNX_MAX_KALLSYMS_ENC_LENGTH + 1) * 256)
1470	return dbgDiggerLinuxFoundMarkers(pThis, DBGFR3AddrSub(&CurAddr, sizeof(uint64_t)), sizeof(uint64_t));
1471
1472	uint32_t const cEntries = sizeof(uBuf) / sizeof(uint64_t);
1473	for (uint32_t i = offBuf / sizeof(uint64_t); i < cEntries; i++)
1474	if (uBuf.au64[i] == 0)
1475	{
1476	if (RT_UNLIKELY(i + 1 >= cEntries))
1477	{
1478	fPendingZeroHit = true;
1479	break;
1480	}
1481	if ( uBuf.au64[i + 1] >= (LNX_MIN_KALLSYMS_ENC_LENGTH + 1) * 256
1482	&& uBuf.au64[i + 1] <= (LNX_MAX_KALLSYMS_ENC_LENGTH + 1) * 256)
1483	return dbgDiggerLinuxFoundMarkers(pThis, DBGFR3AddrAdd(&CurAddr, i * sizeof(uint64_t)), sizeof(uint64_t));
1484	}
1485	}
1486	else
1487	{
1488	if ( RT_UNLIKELY(fPendingZeroHit)
1489	&& uBuf.au32[0] >= (LNX_MIN_KALLSYMS_ENC_LENGTH + 1) * 256
1490	&& uBuf.au32[0] <= (LNX_MAX_KALLSYMS_ENC_LENGTH + 1) * 256)
1491	return dbgDiggerLinuxFoundMarkers(pThis, DBGFR3AddrSub(&CurAddr, sizeof(uint32_t)), sizeof(uint32_t));
1492
1493	uint32_t const cEntries = sizeof(uBuf) / sizeof(uint32_t);
1494	for (uint32_t i = offBuf / sizeof(uint32_t); i < cEntries; i++)
1495	if (uBuf.au32[i] == 0)
1496	{
1497	if (RT_UNLIKELY(i + 1 >= cEntries))
1498	{
1499	fPendingZeroHit = true;
1500	break;
1501	}
1502	if ( uBuf.au32[i + 1] >= (LNX_MIN_KALLSYMS_ENC_LENGTH + 1) * 256
1503	&& uBuf.au32[i + 1] <= (LNX_MAX_KALLSYMS_ENC_LENGTH + 1) * 256)
1504	return dbgDiggerLinuxFoundMarkers(pThis, DBGFR3AddrAdd(&CurAddr, i * sizeof(uint32_t)), sizeof(uint32_t));
1505	}
1506	}
1507
1508	/*
1509	* Advance
1510	*/
1511	if (RT_UNLIKELY(cbLeft <= sizeof(uBuf)))
1512	{
1513	Log(("dbgDiggerLinuxFindEndOfNamesAndMore: failed (pHitAddr=%RGv)\n", pHitAddr->FlatPtr));
1514	return VERR_NOT_FOUND;
1515	}
1516	cbLeft -= sizeof(uBuf);
1517	DBGFR3AddrAdd(&CurAddr, sizeof(uBuf));
1518	offBuf = 0;
1519	}
1520	}
1521
1522
1523	/**
1524	* Locates the kallsyms_token_index table.
1525	*
1526	* Storing the address in pThis->AddrKernelTokenIndex and the size of the token
1527	* table in pThis->cbKernelTokenTable.
1528	*
1529	* @returns VBox status code.
1530	* @param pUVM The user mode VM handle.
1531	* @param pThis The Linux digger data.
1532	*/
1533	static int dbgDiggerLinuxFindTokenIndex(PUVM pUVM, PDBGDIGGERLINUX pThis)
1534	{
1535	/*
1536	* The kallsyms_token_table is very much like a string table. Due to the
1537	* nature of the compression algorithm it is reasonably short (one example
1538	* here is 853 bytes), so we'll not be reading it in chunks but in full.
1539	* To be on the safe side, we read 8KB, ASSUMING we won't run into unmapped
1540	* memory or any other nasty stuff...
1541	*/
1542	union
1543	{
1544	uint8_t ab[0x2000];
1545	uint16_t au16[0x2000 / sizeof(uint16_t)];
1546	} uBuf;
1547	DBGFADDRESS CurAddr = pThis->AddrKernelTokenTable;
1548	int rc = DBGFR3MemRead(pUVM, 0 /idCpu/, &CurAddr, &uBuf, sizeof(uBuf));
1549	if (RT_FAILURE(rc))
1550	return rc;
1551
1552	/*
1553	* We've got two choices here, either walk the string table or look for
1554	* the next structure, kallsyms_token_index.
1555	*
1556	* The token index is a table of 256 uint16_t entries (index by bytes
1557	* from kallsyms_names) that gives offsets in kallsyms_token_table. It
1558	* starts with a zero entry and the following entries are sorted in
1559	* ascending order. The range of the entries are reasonably small since
1560	* kallsyms_token_table is small.
1561	*
1562	* The alignment seems to be sizeof(unsigned long), just like
1563	* kallsyms_token_table.
1564	*
1565	* So, we start by looking for a zero 16-bit entry.
1566	*/
1567	uint32_t cIncr = (pThis->f64Bit ? sizeof(uint64_t) : sizeof(uint32_t)) / sizeof(uint16_t);
1568
1569	for (uint32_t i = 0; i < sizeof(uBuf) / sizeof(uint16_t) - 16; i += cIncr)
1570	if ( uBuf.au16[i] == 0
1571	&& uBuf.au16[i + 1] > 0
1572	&& uBuf.au16[i + 1] <= LNX_MAX_KALLSYMS_TOKEN_LEN
1573	&& (uint16_t)(uBuf.au16[i + 2] - uBuf.au16[i + 1] - 1U) <= (uint16_t)LNX_MAX_KALLSYMS_TOKEN_LEN
1574	&& (uint16_t)(uBuf.au16[i + 3] - uBuf.au16[i + 2] - 1U) <= (uint16_t)LNX_MAX_KALLSYMS_TOKEN_LEN
1575	&& (uint16_t)(uBuf.au16[i + 4] - uBuf.au16[i + 3] - 1U) <= (uint16_t)LNX_MAX_KALLSYMS_TOKEN_LEN
1576	&& (uint16_t)(uBuf.au16[i + 5] - uBuf.au16[i + 4] - 1U) <= (uint16_t)LNX_MAX_KALLSYMS_TOKEN_LEN
1577	&& (uint16_t)(uBuf.au16[i + 6] - uBuf.au16[i + 5] - 1U) <= (uint16_t)LNX_MAX_KALLSYMS_TOKEN_LEN
1578	)
1579	{
1580	pThis->AddrKernelTokenIndex = CurAddr;
1581	DBGFR3AddrAdd(&pThis->AddrKernelTokenIndex, i * sizeof(uint16_t));
1582	pThis->cbKernelTokenTable = i * sizeof(uint16_t);
1583	return VINF_SUCCESS;
1584	}
1585
1586	Log(("dbgDiggerLinuxFindTokenIndex: Failed (%RGv..%RGv)\n", CurAddr.FlatPtr, CurAddr.FlatPtr + (RTGCUINTPTR)sizeof(uBuf)));
1587	return VERR_NOT_FOUND;
1588	}
1589
1590
1591	/**
1592	* Loads the kernel symbols from the given kallsyms offset table decoding the symbol names
1593	* (worker common for dbgDiggerLinuxLoadKernelSymbolsAbsolute() and dbgDiggerLinuxLoadKernelSymbolsRelative()).
1594	*
1595	* @returns VBox status code.
1596	* @param pUVM The user mode VM handle.
1597	* @param pThis The Linux digger data.
1598	* @param uKernelStart Flat kernel start address.
1599	* @param cbKernel Size of the kernel in bytes.
1600	* @param pauSymOff Pointer to the array of symbol offsets in the kallsyms table
1601	* relative to the start of the kernel.
1602	*/
1603	static int dbgDiggerLinuxLoadKernelSymbolsWorker(PUVM pUVM, PDBGDIGGERLINUX pThis, RTGCUINTPTR uKernelStart,
1604	RTGCUINTPTR cbKernel, RTGCUINTPTR *pauSymOff)
1605	{
1606	uint8_t pbNames = (uint8_t )RTMemAllocZ(pThis->cbKernelNames);
1607	int rc = DBGFR3MemRead(pUVM, 0 /idCpu/, &pThis->AddrKernelNames, pbNames, pThis->cbKernelNames);
1608	if (RT_SUCCESS(rc))
1609	{
1610	char pszzTokens = (char )RTMemAllocZ(pThis->cbKernelTokenTable);
1611	rc = DBGFR3MemRead(pUVM, 0 /idCpu/, &pThis->AddrKernelTokenTable, pszzTokens, pThis->cbKernelTokenTable);
1612	if (RT_SUCCESS(rc))
1613	{
1614	uint16_t paoffTokens = (uint16_t )RTMemAllocZ(256 * sizeof(uint16_t));
1615	rc = DBGFR3MemRead(pUVM, 0 /idCpu/, &pThis->AddrKernelTokenIndex, paoffTokens, 256 * sizeof(uint16_t));
1616	if (RT_SUCCESS(rc))
1617	{
1618	/*
1619	* Create a module for the kernel.
1620	*/
1621	RTDBGMOD hMod;
1622	rc = RTDbgModCreate(&hMod, "vmlinux", cbKernel, 0 /fFlags/);
1623	if (RT_SUCCESS(rc))
1624	{
1625	rc = RTDbgModSetTag(hMod, DIG_LNX_MOD_TAG); AssertRC(rc);
1626	rc = VINF_SUCCESS;
1627
1628	/*
1629	* Enumerate the symbols.
1630	*/
1631	uint32_t offName = 0;
1632	uint32_t cLeft = pThis->cKernelSymbols;
1633	while (cLeft-- > 0 && RT_SUCCESS(rc))
1634	{
1635	/* Decode the symbol name first. */
1636	if (RT_LIKELY(offName < pThis->cbKernelNames))
1637	{
1638	uint8_t cbName = pbNames[offName++];
1639	if (RT_LIKELY(offName + cbName <= pThis->cbKernelNames))
1640	{
1641	char szSymbol[4096];
1642	uint32_t offSymbol = 0;
1643	while (cbName-- > 0)
1644	{
1645	uint8_t bEnc = pbNames[offName++];
1646	uint16_t offToken = paoffTokens[bEnc];
1647	if (RT_LIKELY(offToken < pThis->cbKernelTokenTable))
1648	{
1649	const char *pszToken = &pszzTokens[offToken];
1650	char ch;
1651	while ((ch = *pszToken++) != '\0')
1652	if (offSymbol < sizeof(szSymbol) - 1)
1653	szSymbol[offSymbol++] = ch;
1654	}
1655	else
1656	{
1657	rc = VERR_INVALID_UTF8_ENCODING;
1658	break;
1659	}
1660	}
1661	szSymbol[offSymbol < sizeof(szSymbol) ? offSymbol : sizeof(szSymbol) - 1] = '\0';
1662
1663	/* The offset. */
1664	RTGCUINTPTR uSymOff = *pauSymOff;
1665	pauSymOff++;
1666
1667	/* Add it without the type char. */
1668	if (uSymOff <= cbKernel)
1669	{
1670	rc = RTDbgModSymbolAdd(hMod, &szSymbol[1], RTDBGSEGIDX_RVA, uSymOff,
1671	0 /cb/, 0 /fFlags/, NULL);
1672	if (RT_FAILURE(rc))
1673	{
1674	if ( rc == VERR_DBG_SYMBOL_NAME_OUT_OF_RANGE
1675	\|\| rc == VERR_DBG_INVALID_RVA
1676	\|\| rc == VERR_DBG_ADDRESS_CONFLICT
1677	\|\| rc == VERR_DBG_DUPLICATE_SYMBOL)
1678	{
1679	Log2(("dbgDiggerLinuxLoadKernelSymbols: RTDbgModSymbolAdd(,%s,) failed %Rrc (ignored)\n", szSymbol, rc));
1680	rc = VINF_SUCCESS;
1681	}
1682	else
1683	Log(("dbgDiggerLinuxLoadKernelSymbols: RTDbgModSymbolAdd(,%s,) failed %Rrc\n", szSymbol, rc));
1684	}
1685	}
1686	}
1687	else
1688	{
1689	rc = VERR_END_OF_STRING;
1690	Log(("dbgDiggerLinuxLoadKernelSymbols: offName=%#x cLeft=%#x cbName=%#x cbKernelNames=%#x\n",
1691	offName, cLeft, cbName, pThis->cbKernelNames));
1692	}
1693	}
1694	else
1695	{
1696	rc = VERR_END_OF_STRING;
1697	Log(("dbgDiggerLinuxLoadKernelSymbols: offName=%#x cLeft=%#x cbKernelNames=%#x\n",
1698	offName, cLeft, pThis->cbKernelNames));
1699	}
1700	}
1701
1702	/*
1703	* Link the module into the address space.
1704	*/
1705	if (RT_SUCCESS(rc))
1706	{
1707	RTDBGAS hAs = DBGFR3AsResolveAndRetain(pUVM, DBGF_AS_KERNEL);
1708	if (hAs != NIL_RTDBGAS)
1709	rc = RTDbgAsModuleLink(hAs, hMod, uKernelStart, RTDBGASLINK_FLAGS_REPLACE);
1710	else
1711	rc = VERR_INTERNAL_ERROR;
1712	RTDbgAsRelease(hAs);
1713	}
1714	else
1715	Log(("dbgDiggerLinuxLoadKernelSymbols: Failed: %Rrc\n", rc));
1716	RTDbgModRelease(hMod);
1717	}
1718	else
1719	Log(("dbgDiggerLinuxLoadKernelSymbols: RTDbgModCreate failed: %Rrc\n", rc));
1720	}
1721	else
1722	Log(("dbgDiggerLinuxLoadKernelSymbols: Reading token index at %RGv failed: %Rrc\n",
1723	pThis->AddrKernelTokenIndex.FlatPtr, rc));
1724	RTMemFree(paoffTokens);
1725	}
1726	else
1727	Log(("dbgDiggerLinuxLoadKernelSymbols: Reading token table at %RGv failed: %Rrc\n",
1728	pThis->AddrKernelTokenTable.FlatPtr, rc));
1729	RTMemFree(pszzTokens);
1730	}
1731	else
1732	Log(("dbgDiggerLinuxLoadKernelSymbols: Reading encoded names at %RGv failed: %Rrc\n",
1733	pThis->AddrKernelNames.FlatPtr, rc));
1734	RTMemFree(pbNames);
1735
1736	return rc;
1737	}
1738
1739	/**
1740	* Loads the kernel symbols from the kallsyms table if it contains absolute addresses
1741	*
1742	* @returns VBox status code.
1743	* @param pUVM The user mode VM handle.
1744	* @param pThis The Linux digger data.
1745	*/
1746	static int dbgDiggerLinuxLoadKernelSymbolsAbsolute(PUVM pUVM, PDBGDIGGERLINUX pThis)
1747	{
1748	/*
1749	* Allocate memory for temporary table copies, reading the tables as we go.
1750	*/
1751	uint32_t const cbGuestAddr = pThis->f64Bit ? sizeof(uint64_t) : sizeof(uint32_t);
1752	void pvAddresses = RTMemAllocZ(pThis->cKernelSymbols cbGuestAddr);
1753	int rc = DBGFR3MemRead(pUVM, 0 /idCpu/, &pThis->AddrKernelAddresses, pvAddresses, pThis->cKernelSymbols * cbGuestAddr);
1754	if (RT_SUCCESS(rc))
1755	{
1756	/*
1757	* Figure out the kernel start and end and convert the absolute addresses to relative offsets.
1758	*/
1759	RTGCUINTPTR uKernelStart = pThis->AddrKernelAddresses.FlatPtr;
1760	RTGCUINTPTR uKernelEnd = pThis->AddrKernelTokenIndex.FlatPtr + 256 * sizeof(uint16_t);
1761	RTGCUINTPTR pauSymOff = (RTGCUINTPTR )RTMemTmpAllocZ(pThis->cKernelSymbols * sizeof(RTGCUINTPTR));
1762	uint32_t i;
1763	if (cbGuestAddr == sizeof(uint64_t))
1764	{
1765	uint64_t pauAddrs = (uint64_t )pvAddresses;
1766	for (i = 0; i < pThis->cKernelSymbols; i++)
1767	if ( pauAddrs[i] < uKernelStart
1768	&& LNX64_VALID_ADDRESS(pauAddrs[i])
1769	&& uKernelStart - pauAddrs[i] < LNX_MAX_KERNEL_SIZE)
1770	uKernelStart = pauAddrs[i];
1771
1772	for (i = pThis->cKernelSymbols - 1; i > 0; i--)
1773	if ( pauAddrs[i] > uKernelEnd
1774	&& LNX64_VALID_ADDRESS(pauAddrs[i])
1775	&& pauAddrs[i] - uKernelEnd < LNX_MAX_KERNEL_SIZE)
1776	uKernelEnd = pauAddrs[i];
1777
1778	for (i = 0; i < pThis->cKernelSymbols; i++)
1779	pauSymOff[i] = pauAddrs[i] - uKernelStart;
1780	}
1781	else
1782	{
1783	uint32_t pauAddrs = (uint32_t )pvAddresses;
1784	for (i = 0; i < pThis->cKernelSymbols; i++)
1785	if ( pauAddrs[i] < uKernelStart
1786	&& LNX32_VALID_ADDRESS(pauAddrs[i])
1787	&& uKernelStart - pauAddrs[i] < LNX_MAX_KERNEL_SIZE)
1788	uKernelStart = pauAddrs[i];
1789
1790	for (i = pThis->cKernelSymbols - 1; i > 0; i--)
1791	if ( pauAddrs[i] > uKernelEnd
1792	&& LNX32_VALID_ADDRESS(pauAddrs[i])
1793	&& pauAddrs[i] - uKernelEnd < LNX_MAX_KERNEL_SIZE)
1794	uKernelEnd = pauAddrs[i];
1795
1796	for (i = 0; i < pThis->cKernelSymbols; i++)
1797	pauSymOff[i] = pauAddrs[i] - uKernelStart;
1798	}
1799
1800	RTGCUINTPTR cbKernel = uKernelEnd - uKernelStart;
1801	pThis->cbKernel = (uint32_t)cbKernel;
1802	DBGFR3AddrFromFlat(pUVM, &pThis->AddrKernelBase, uKernelStart);
1803	Log(("dbgDiggerLinuxLoadKernelSymbolsAbsolute: uKernelStart=%RGv cbKernel=%#x\n", uKernelStart, cbKernel));
1804
1805	rc = dbgDiggerLinuxLoadKernelSymbolsWorker(pUVM, pThis, uKernelStart, cbKernel, pauSymOff);
1806	if (RT_FAILURE(rc))
1807	Log(("dbgDiggerLinuxLoadKernelSymbolsAbsolute: Loading symbols from given offset table failed: %Rrc\n", rc));
1808	RTMemTmpFree(pauSymOff);
1809	}
1810	else
1811	Log(("dbgDiggerLinuxLoadKernelSymbolsAbsolute: Reading symbol addresses at %RGv failed: %Rrc\n",
1812	pThis->AddrKernelAddresses.FlatPtr, rc));
1813	RTMemFree(pvAddresses);
1814
1815	return rc;
1816	}
1817
1818
1819	/**
1820	* Loads the kernel symbols from the kallsyms table if it contains absolute addresses
1821	*
1822	* @returns VBox status code.
1823	* @param pUVM The user mode VM handle.
1824	* @param pThis The Linux digger data.
1825	*/
1826	static int dbgDiggerLinuxLoadKernelSymbolsRelative(PUVM pUVM, PDBGDIGGERLINUX pThis)
1827	{
1828	/*
1829	* Allocate memory for temporary table copies, reading the tables as we go.
1830	*/
1831	int32_t pai32Offsets = (int32_t )RTMemAllocZ(pThis->cKernelSymbols * sizeof(int32_t));
1832	int rc = DBGFR3MemRead(pUVM, 0 /idCpu/, &pThis->AddrKernelAddresses, pai32Offsets, pThis->cKernelSymbols * sizeof(int32_t));
1833	if (RT_SUCCESS(rc))
1834	{
1835	/*
1836	* Figure out the kernel start and end and convert the absolute addresses to relative offsets.
1837	*/
1838	RTGCUINTPTR uKernelStart = pThis->AddrKernelAddresses.FlatPtr;
1839	RTGCUINTPTR uKernelEnd = pThis->AddrKernelTokenIndex.FlatPtr + 256 * sizeof(uint16_t);
1840	RTGCUINTPTR pauSymOff = (RTGCUINTPTR )RTMemTmpAllocZ(pThis->cKernelSymbols * sizeof(RTGCUINTPTR));
1841	uint32_t i;
1842
1843	for (i = 0; i < pThis->cKernelSymbols; i++)
1844	{
1845	RTGCUINTPTR uSymAddr = dbgDiggerLinuxConvOffsetToAddr(pThis, pai32Offsets[i]);
1846
1847	if ( uSymAddr < uKernelStart
1848	&& (pThis->f64Bit ? LNX64_VALID_ADDRESS(uSymAddr) : LNX32_VALID_ADDRESS(uSymAddr))
1849	&& uKernelStart - uSymAddr < LNX_MAX_KERNEL_SIZE)
1850	uKernelStart = uSymAddr;
1851	}
1852
1853	for (i = pThis->cKernelSymbols - 1; i > 0; i--)
1854	{
1855	RTGCUINTPTR uSymAddr = dbgDiggerLinuxConvOffsetToAddr(pThis, pai32Offsets[i]);
1856
1857	if ( uSymAddr > uKernelEnd
1858	&& (pThis->f64Bit ? LNX64_VALID_ADDRESS(uSymAddr) : LNX32_VALID_ADDRESS(uSymAddr))
1859	&& uSymAddr - uKernelEnd < LNX_MAX_KERNEL_SIZE)
1860	uKernelEnd = uSymAddr;
1861
1862	/* Store the offset from the derived kernel start address. */
1863	pauSymOff[i] = uSymAddr - uKernelStart;
1864	}
1865
1866	RTGCUINTPTR cbKernel = uKernelEnd - uKernelStart;
1867	pThis->cbKernel = (uint32_t)cbKernel;
1868	DBGFR3AddrFromFlat(pUVM, &pThis->AddrKernelBase, uKernelStart);
1869	Log(("dbgDiggerLinuxLoadKernelSymbolsRelative: uKernelStart=%RGv cbKernel=%#x\n", uKernelStart, cbKernel));
1870
1871	rc = dbgDiggerLinuxLoadKernelSymbolsWorker(pUVM, pThis, uKernelStart, cbKernel, pauSymOff);
1872	if (RT_FAILURE(rc))
1873	Log(("dbgDiggerLinuxLoadKernelSymbolsRelative: Loading symbols from given offset table failed: %Rrc\n", rc));
1874	RTMemTmpFree(pauSymOff);
1875	}
1876	else
1877	Log(("dbgDiggerLinuxLoadKernelSymbolsRelative: Reading symbol addresses at %RGv failed: %Rrc\n",
1878	pThis->AddrKernelAddresses.FlatPtr, rc));
1879	RTMemFree(pai32Offsets);
1880
1881	return rc;
1882	}
1883
1884
1885	/**
1886	* Loads the kernel symbols.
1887	*
1888	* @returns VBox status code.
1889	* @param pUVM The user mode VM handle.
1890	* @param pThis The Linux digger data.
1891	*/
1892	static int dbgDiggerLinuxLoadKernelSymbols(PUVM pUVM, PDBGDIGGERLINUX pThis)
1893	{
1894	if (pThis->fRelKrnlAddr)
1895	return dbgDiggerLinuxLoadKernelSymbolsRelative(pUVM, pThis);
1896	else
1897	return dbgDiggerLinuxLoadKernelSymbolsAbsolute(pUVM, pThis);
1898	}
1899
1900	/**
1901	* Checks if there is a likely kallsyms_names fragment at pHitAddr.
1902	*
1903	* @returns true if it's a likely fragment, false if not.
1904	* @param pUVM The user mode VM handle.
1905	* @param pHitAddr The address where paNeedle was found.
1906	* @param pabNeedle The fragment we've been searching for.
1907	* @param cbNeedle The length of the fragment.
1908	*/
1909	static bool dbgDiggerLinuxIsLikelyNameFragment(PUVM pUVM, PCDBGFADDRESS pHitAddr, uint8_t const *pabNeedle, uint8_t cbNeedle)
1910	{
1911	/*
1912	* Examples of lead and tail bytes of our choosen needle in a randomly
1913	* picked kernel:
1914	* k o b j
1915	* 22 6b 6f 62 6a aa
1916	* fc 6b 6f 62 6a aa
1917	* 82 6b 6f 62 6a 5f - ascii trail byte (_).
1918	* ee 6b 6f 62 6a aa
1919	* fc 6b 6f 62 6a 5f - ascii trail byte (_).
1920	* 0a 74 6b 6f 62 6a 5f ea - ascii lead (t) and trail (_) bytes.
1921	* 0b 54 6b 6f 62 6a aa - ascii lead byte (T).
1922	* ... omitting 29 samples similar to the last two ...
1923	* d8 6b 6f 62 6a aa
1924	* d8 6b 6f 62 6a aa
1925	* d8 6b 6f 62 6a aa
1926	* d8 6b 6f 62 6a aa
1927	* f9 5f 6b 6f 62 6a 5f 94 - ascii lead and trail bytes (_)
1928	* f9 5f 6b 6f 62 6a 0c - ascii lead byte (_).
1929	* fd 6b 6f 62 6a 0f
1930	* ... enough.
1931	*/
1932	uint8_t abBuf[32];
1933	DBGFADDRESS ReadAddr = *pHitAddr;
1934	DBGFR3AddrSub(&ReadAddr, 2);
1935	int rc = DBGFR3MemRead(pUVM, 0 /idCpu/, &ReadAddr, abBuf, 2 + cbNeedle + 2);
1936	if (RT_SUCCESS(rc))
1937	{
1938	if (memcmp(&abBuf[2], pabNeedle, cbNeedle) == 0) /* paranoia */
1939	{
1940	uint8_t const bLead = abBuf[1] == '_' \|\| abBuf[1] == 'T' \|\| abBuf[1] == 't' ? abBuf[0] : abBuf[1];
1941	uint8_t const offTail = 2 + cbNeedle;
1942	uint8_t const bTail = abBuf[offTail] == '_' ? abBuf[offTail] : abBuf[offTail + 1];
1943	if ( bLead >= 1 && (bLead < 0x20 \|\| bLead >= 0x80)
1944	&& bTail >= 1 && (bTail < 0x20 \|\| bTail >= 0x80))
1945	return true;
1946	Log(("dbgDiggerLinuxIsLikelyNameFragment: failed at %RGv: bLead=%#x bTail=%#x (offTail=%#x)\n",
1947	pHitAddr->FlatPtr, bLead, bTail, offTail));
1948	}
1949	else
1950	Log(("dbgDiggerLinuxIsLikelyNameFragment: failed at %RGv: Needle changed!\n", pHitAddr->FlatPtr));
1951	}
1952	else
1953	Log(("dbgDiggerLinuxIsLikelyNameFragment: failed at %RGv: %Rrc\n", pHitAddr->FlatPtr, rc));
1954
1955	return false;
1956	}
1957
1958	/**
1959	* Tries to find and load the kernel symbol table with the given needle.
1960	*
1961	* @returns VBox status code.
1962	* @param pThis The Linux digger data.
1963	* @param pUVM The user mode VM handle.
1964	* @param pabNeedle The needle to use for searching.
1965	* @param cbNeedle Size of the needle in bytes.
1966	*/
1967	static int dbgDiggerLinuxFindSymbolTableFromNeedle(PDBGDIGGERLINUX pThis, PUVM pUVM, uint8_t const *pabNeedle, uint8_t cbNeedle)
1968	{
1969	int rc = VINF_SUCCESS;
1970
1971	/*
1972	* Go looking for the kallsyms table. If it's there, it will be somewhere
1973	* after the linux_banner symbol, so use it for starting the search.
1974	*/
1975	DBGFADDRESS CurAddr = pThis->AddrLinuxBanner;
1976	uint32_t cbLeft = LNX_MAX_KERNEL_SIZE;
1977	while (cbLeft > 4096)
1978	{
1979	DBGFADDRESS HitAddr;
1980	rc = DBGFR3MemScan(pUVM, 0 /idCpu/, &CurAddr, cbLeft, 1 /uAlign/,
1981	pabNeedle, cbNeedle, &HitAddr);
1982	if (RT_FAILURE(rc))
1983	break;
1984	if (dbgDiggerLinuxIsLikelyNameFragment(pUVM, &HitAddr, pabNeedle, cbNeedle))
1985	{
1986	/* There will be another hit near by. */
1987	DBGFR3AddrAdd(&HitAddr, 1);
1988	rc = DBGFR3MemScan(pUVM, 0 /idCpu/, &HitAddr, LNX_MAX_KALLSYMS_NAMES_SIZE, 1 /uAlign/,
1989	pabNeedle, cbNeedle, &HitAddr);
1990	if ( RT_SUCCESS(rc)
1991	&& dbgDiggerLinuxIsLikelyNameFragment(pUVM, &HitAddr, pabNeedle, cbNeedle))
1992	{
1993	/*
1994	* We've got a very likely candidate for a location inside kallsyms_names.
1995	* Try find the start of it, that is to say, try find kallsyms_num_syms.
1996	* kallsyms_num_syms is aligned on sizeof(unsigned long) boundrary
1997	*/
1998	rc = dbgDiggerLinuxFindStartOfNamesAndSymbolCount(pUVM, pThis, &HitAddr);
1999	if (RT_SUCCESS(rc))
2000	rc = dbgDiggerLinuxFindEndOfNamesAndMore(pUVM, pThis, &HitAddr);
2001	if (RT_SUCCESS(rc))
2002	rc = dbgDiggerLinuxFindTokenIndex(pUVM, pThis);
2003	if (RT_SUCCESS(rc))
2004	rc = dbgDiggerLinuxLoadKernelSymbols(pUVM, pThis);
2005	if (RT_SUCCESS(rc))
2006	break;
2007	}
2008	}
2009
2010	/*
2011	* Advance.
2012	*/
2013	RTGCUINTPTR cbDistance = HitAddr.FlatPtr - CurAddr.FlatPtr + cbNeedle;
2014	if (RT_UNLIKELY(cbDistance >= cbLeft))
2015	{
2016	Log(("dbgDiggerLinuxInit: Failed to find kallsyms\n"));
2017	break;
2018	}
2019	cbLeft -= cbDistance;
2020	DBGFR3AddrAdd(&CurAddr, cbDistance);
2021
2022	}
2023
2024	return rc;
2025	}
2026
2027	/**
2028	* Skips whitespace and comments in the given config returning the pointer
2029	* to the first non whitespace character.
2030	*
2031	* @returns Pointer to the first non whitespace character or NULL if the end
2032	* of the string was reached.
2033	* @param pszCfg The config string.
2034	*/
2035	static const char dbgDiggerLinuxCfgSkipWhitespace(const char pszCfg)
2036	{
2037	do
2038	{
2039	while ( *pszCfg != '\0'
2040	&& ( RT_C_IS_SPACE(*pszCfg)
2041	\|\| *pszCfg == '\n'))
2042	pszCfg++;
2043
2044	/* Do we have a comment? Skip it. */
2045	if (*pszCfg == '#')
2046	{
2047	while ( *pszCfg != '\n'
2048	&& *pszCfg != '\0')
2049	pszCfg++;
2050	}
2051	} while ( *pszCfg != '\0'
2052	&& ( RT_C_IS_SPACE(*pszCfg)
2053	\|\| *pszCfg == '\n'
2054	\|\| *pszCfg == '#'));
2055
2056	return pszCfg;
2057	}
2058
2059	/**
2060	* Parses an identifier at the given position.
2061	*
2062	* @returns VBox status code.
2063	* @param pszCfg The config data.
2064	* @param ppszCfgNext Where to store the pointer to the data following the identifier.
2065	* @param ppszIde Where to store the pointer to the identifier on success.
2066	* Free with RTStrFree().
2067	*/
2068	static int dbgDiggerLinuxCfgParseIde(const char pszCfg, const char ppszCfgNext, char *ppszIde)
2069	{
2070	int rc = VINF_SUCCESS;
2071	size_t cchIde = 0;
2072
2073	while ( *pszCfg != '\0'
2074	&& ( RT_C_IS_ALNUM(*pszCfg)
2075	\|\| *pszCfg == '_'))
2076	{
2077	cchIde++;
2078	pszCfg++;
2079	}
2080
2081	if (cchIde)
2082	{
2083	*ppszIde = RTStrDupN(pszCfg - cchIde, cchIde);
2084	if (!*ppszIde)
2085	rc = VERR_NO_STR_MEMORY;
2086	}
2087
2088	*ppszCfgNext = pszCfg;
2089	return rc;
2090	}
2091
2092	/**
2093	* Parses a value for a config item.
2094	*
2095	* @returns VBox status code.
2096	* @param pszCfg The config data.
2097	* @param ppszCfgNext Where to store the pointer to the data following the identifier.
2098	* @param ppCfgItem Where to store the created config item on success.
2099	*/
2100	static int dbgDiggerLinuxCfgParseVal(const char pszCfg, const char *ppszCfgNext,
2101	PDBGDIGGERLINUXCFGITEM *ppCfgItem)
2102	{
2103	int rc = VINF_SUCCESS;
2104	PDBGDIGGERLINUXCFGITEM pCfgItem = NULL;
2105
2106	if (RT_C_IS_DIGIT(pszCfg) \|\| pszCfg == '-')
2107	{
2108	/* Parse the number. */
2109	int64_t i64Num;
2110	rc = RTStrToInt64Ex(pszCfg, (char **)ppszCfgNext, 0, &i64Num);
2111	if ( RT_SUCCESS(rc)
2112	\|\| rc == VWRN_TRAILING_CHARS
2113	\|\| rc == VWRN_TRAILING_SPACES)
2114	{
2115	pCfgItem = (PDBGDIGGERLINUXCFGITEM)RTMemAllocZ(sizeof(DBGDIGGERLINUXCFGITEM));
2116	if (pCfgItem)
2117	{
2118	pCfgItem->enmType = DBGDIGGERLINUXCFGITEMTYPE_NUMBER;
2119	pCfgItem->u.i64Num = i64Num;
2120	}
2121	else
2122	rc = VERR_NO_MEMORY;
2123	}
2124	}
2125	else if (*pszCfg == '\"')
2126	{
2127	/* Parse a string. */
2128	const char *pszCfgCur = pszCfg + 1;
2129	while ( *pszCfgCur != '\0'
2130	&& *pszCfgCur != '\"')
2131	pszCfgCur++;
2132
2133	if (*pszCfgCur == '\"')
2134	{
2135	pCfgItem = (PDBGDIGGERLINUXCFGITEM)RTMemAllocZ(RT_OFFSETOF(DBGDIGGERLINUXCFGITEM, u.aszString[pszCfgCur - pszCfg + 1]));
2136	if (pCfgItem)
2137	{
2138	pCfgItem->enmType = DBGDIGGERLINUXCFGITEMTYPE_STRING;
2139	RTStrCopyEx(&pCfgItem->u.aszString[0], pszCfgCur - pszCfg + 1, pszCfg, pszCfgCur - pszCfg);
2140	*ppszCfgNext = pszCfgCur + 1;
2141	}
2142	else
2143	rc = VERR_NO_MEMORY;
2144	}
2145	else
2146	rc = VERR_INVALID_STATE;
2147	}
2148	else if ( *pszCfg == 'y'
2149	\|\| *pszCfg == 'm')
2150	{
2151	/* Included or module. */
2152	pCfgItem = (PDBGDIGGERLINUXCFGITEM)RTMemAllocZ(sizeof(DBGDIGGERLINUXCFGITEM));
2153	if (pCfgItem)
2154	{
2155	pCfgItem->enmType = DBGDIGGERLINUXCFGITEMTYPE_FLAG;
2156	pCfgItem->u.fModule = *pszCfg == 'm';
2157	}
2158	else
2159	rc = VERR_NO_MEMORY;
2160	pszCfg++;
2161	*ppszCfgNext = pszCfg;
2162	}
2163	else
2164	rc = VERR_INVALID_STATE;
2165
2166	if (RT_SUCCESS(rc))
2167	*ppCfgItem = pCfgItem;
2168	else if (pCfgItem)
2169	RTMemFree(pCfgItem);
2170
2171	return rc;
2172	}
2173
2174	/**
2175	* Parses the given kernel config and creates the config database.
2176	*
2177	* @returns VBox status code
2178	* @param pThis The Linux digger data.
2179	* @param pszCfg The config string.
2180	*/
2181	static int dbgDiggerLinuxCfgParse(PDBGDIGGERLINUX pThis, const char *pszCfg)
2182	{
2183	int rc = VINF_SUCCESS;
2184
2185	/*
2186	* The config is a text file with the following elements:
2187	* # starts a comment which goes till the end of the line
2188	* <Ide>=<val> where <Ide> is an identifier consisting of
2189	* alphanumerical characters (including _)
2190	* <val> denotes the value for the identifier and can have the following
2191	* formats:
2192	* (-)[0-9]* for numbers
2193	* "..." for a string value
2194	* m when a feature is enabled as a module
2195	* y when a feature is enabled
2196	* Newlines are used as a separator between values and mark the end
2197	* of a comment
2198	*/
2199	const char *pszCfgCur = pszCfg;
2200	while ( RT_SUCCESS(rc)
2201	&& *pszCfgCur != '\0')
2202	{
2203	/* Start skipping the whitespace. */
2204	pszCfgCur = dbgDiggerLinuxCfgSkipWhitespace(pszCfgCur);
2205	if ( pszCfgCur
2206	&& *pszCfgCur != '\0')
2207	{
2208	char *pszIde = NULL;
2209	/* Must be an identifier, parse it. */
2210	rc = dbgDiggerLinuxCfgParseIde(pszCfgCur, &pszCfgCur, &pszIde);
2211	if (RT_SUCCESS(rc))
2212	{
2213	/*
2214	* Skip whitespace again (shouldn't be required because = follows immediately
2215	* in the observed configs).
2216	*/
2217	pszCfgCur = dbgDiggerLinuxCfgSkipWhitespace(pszCfgCur);
2218	if ( pszCfgCur
2219	&& *pszCfgCur == '=')
2220	{
2221	pszCfgCur++;
2222	pszCfgCur = dbgDiggerLinuxCfgSkipWhitespace(pszCfgCur);
2223	if ( pszCfgCur
2224	&& *pszCfgCur != '\0')
2225	{
2226	/* Get the value. */
2227	PDBGDIGGERLINUXCFGITEM pCfgItem = NULL;
2228	rc = dbgDiggerLinuxCfgParseVal(pszCfgCur, &pszCfgCur, &pCfgItem);
2229	if (RT_SUCCESS(rc))
2230	{
2231	pCfgItem->Core.pszString = pszIde;
2232	bool fRc = RTStrSpaceInsert(&pThis->hCfgDb, &pCfgItem->Core);
2233	if (!fRc)
2234	{
2235	RTStrFree(pszIde);
2236	RTMemFree(pCfgItem);
2237	rc = VERR_INVALID_STATE;
2238	}
2239	}
2240	}
2241	else
2242	rc = VERR_EOF;
2243	}
2244	else
2245	rc = VERR_INVALID_STATE;
2246	}
2247
2248	if (RT_FAILURE(rc))
2249	RTStrFree(pszIde);
2250	}
2251	else
2252	break; /* Reached the end of the config. */
2253	}
2254
2255	if (RT_FAILURE(rc))
2256	dbgDiggerLinuxCfgDbDestroy(pThis);
2257
2258	return rc;
2259	}
2260
2261	/**
2262	* Decompresses the given config and validates the UTF-8 encoding.
2263	*
2264	* @returns VBox status code.
2265	* @param pbCfgComp The compressed config.
2266	* @param cbCfgComp Size of the compressed config.
2267	* @param ppszCfg Where to store the pointer to the decompressed config
2268	* on success.
2269	*/
2270	static int dbgDiggerLinuxCfgDecompress(const uint8_t pbCfgComp, size_t cbCfgComp, char *ppszCfg)
2271	{
2272	int rc = VINF_SUCCESS;
2273	RTVFSIOSTREAM hVfsIos = NIL_RTVFSIOSTREAM;
2274
2275	rc = RTVfsIoStrmFromBuffer(RTFILE_O_READ, pbCfgComp, cbCfgComp, &hVfsIos);
2276	if (RT_SUCCESS(rc))
2277	{
2278	RTVFSIOSTREAM hVfsIosDecomp = NIL_RTVFSIOSTREAM;
2279	rc = RTZipGzipDecompressIoStream(hVfsIos, RTZIPGZIPDECOMP_F_ALLOW_ZLIB_HDR, &hVfsIosDecomp);
2280	if (RT_SUCCESS(rc))
2281	{
2282	char *pszCfg = NULL;
2283	size_t cchCfg = 0;
2284	size_t cbRead = 0;
2285
2286	do
2287	{
2288	uint8_t abBuf[_64K];
2289	rc = RTVfsIoStrmRead(hVfsIosDecomp, abBuf, sizeof(abBuf), true /fBlocking/, &cbRead);
2290	if (rc == VINF_EOF && cbRead == 0)
2291	rc = VINF_SUCCESS;
2292	if ( RT_SUCCESS(rc)
2293	&& cbRead > 0)
2294	{
2295	/* Append data. */
2296	char *pszCfgNew = pszCfg;
2297	rc = RTStrRealloc(&pszCfgNew, cchCfg + cbRead + 1);
2298	if (RT_SUCCESS(rc))
2299	{
2300	pszCfg = pszCfgNew;
2301	memcpy(pszCfg + cchCfg, &abBuf[0], cbRead);
2302	cchCfg += cbRead;
2303	pszCfg[cchCfg] = '\0'; /* Enforce string termination. */
2304	}
2305	}
2306	} while (RT_SUCCESS(rc) && cbRead > 0);
2307
2308	if (RT_SUCCESS(rc))
2309	*ppszCfg = pszCfg;
2310	else if (RT_FAILURE(rc) && pszCfg)
2311	RTStrFree(pszCfg);
2312
2313	RTVfsIoStrmRelease(hVfsIosDecomp);
2314	}
2315	RTVfsIoStrmRelease(hVfsIos);
2316	}
2317
2318	return rc;
2319	}
2320
2321	/**
2322	* Reads and decodes the compressed kernel config.
2323	*
2324	* @returns VBox status code.
2325	* @param pThis The Linux digger data.
2326	* @param pUVM The user mode VM handle.
2327	* @param pAddrStart The start address of the compressed config.
2328	* @param cbCfgComp The size of the compressed config.
2329	*/
2330	static int dbgDiggerLinuxCfgDecode(PDBGDIGGERLINUX pThis, PUVM pUVM,
2331	PCDBGFADDRESS pAddrStart, size_t cbCfgComp)
2332	{
2333	int rc = VINF_SUCCESS;
2334	uint8_t pbCfgComp = (uint8_t )RTMemTmpAlloc(cbCfgComp);
2335	if (!pbCfgComp)
2336	return VERR_NO_MEMORY;
2337
2338	rc = DBGFR3MemRead(pUVM, 0 /idCpu/, pAddrStart, pbCfgComp, cbCfgComp);
2339	if (RT_SUCCESS(rc))
2340	{
2341	char *pszCfg = NULL;
2342	rc = dbgDiggerLinuxCfgDecompress(pbCfgComp, cbCfgComp, &pszCfg);
2343	if (RT_SUCCESS(rc))
2344	{
2345	if (RTStrIsValidEncoding(pszCfg))
2346	rc = dbgDiggerLinuxCfgParse(pThis, pszCfg);
2347	else
2348	rc = VERR_INVALID_UTF8_ENCODING;
2349	RTStrFree(pszCfg);
2350	}
2351	}
2352
2353	RTMemFree(pbCfgComp);
2354	return rc;
2355	}
2356
2357	/**
2358	* Tries to find the compressed kernel config in the kernel address space
2359	* and sets up the config database.
2360	*
2361	* @returns VBox status code.
2362	* @param pThis The Linux digger data.
2363	* @param pUVM The user mode VM handle.
2364	*/
2365	static int dbgDiggerLinuxCfgFind(PDBGDIGGERLINUX pThis, PUVM pUVM)
2366	{
2367	int rc = VINF_SUCCESS;
2368
2369	/*
2370	* Go looking for the IKCFG_ST string which indicates the start
2371	* of the compressed config file.
2372	*/
2373	static const uint8_t s_abCfgNeedleStart[] = "IKCFG_ST";
2374	static const uint8_t s_abCfgNeedleEnd[] = "IKCFG_ED";
2375	DBGFADDRESS CurAddr = pThis->AddrLinuxBanner;
2376	uint32_t cbLeft = LNX_MAX_KERNEL_SIZE;
2377	while (cbLeft > 4096)
2378	{
2379	DBGFADDRESS HitAddrStart;
2380	rc = DBGFR3MemScan(pUVM, 0 /idCpu/, &CurAddr, cbLeft, 1 /uAlign/,
2381	s_abCfgNeedleStart, sizeof(s_abCfgNeedleStart) - 1, &HitAddrStart);
2382	if (RT_FAILURE(rc))
2383	break;
2384
2385	/* Check for the end marker which shouldn't be that far away. */
2386	DBGFR3AddrAdd(&HitAddrStart, sizeof(s_abCfgNeedleStart) - 1);
2387	DBGFADDRESS HitAddrEnd;
2388	rc = DBGFR3MemScan(pUVM, 0 /* idCpu */, &HitAddrStart, LNX_MAX_COMPRESSED_CFG_SIZE,
2389	1 /* uAlign */, s_abCfgNeedleEnd, sizeof(s_abCfgNeedleEnd) - 1, &HitAddrEnd);
2390	if (RT_SUCCESS(rc))
2391	{
2392	/* Allocate a buffer to hold the compressed data between the markers and fetch it. */
2393	RTGCUINTPTR cbCfg = HitAddrEnd.FlatPtr - HitAddrStart.FlatPtr;
2394	Assert(cbCfg == (size_t)cbCfg);
2395	rc = dbgDiggerLinuxCfgDecode(pThis, pUVM, &HitAddrStart, cbCfg);
2396	if (RT_SUCCESS(rc))
2397	break;
2398	}
2399
2400	/*
2401	* Advance.
2402	*/
2403	RTGCUINTPTR cbDistance = HitAddrStart.FlatPtr - CurAddr.FlatPtr + sizeof(s_abCfgNeedleStart) - 1;
2404	if (RT_UNLIKELY(cbDistance >= cbLeft))
2405	{
2406	LogFunc(("Failed to find compressed kernel config\n"));
2407	break;
2408	}
2409	cbLeft -= cbDistance;
2410	DBGFR3AddrAdd(&CurAddr, cbDistance);
2411
2412	}
2413
2414	return rc;
2415	}
2416
2417	/**
2418	* Probes for a Linux kernel starting at the given address.
2419	*
2420	* @returns Flag whether something which looks like a valid Linux kernel was found.
2421	* @param pThis The Linux digger data.
2422	* @param pUVM The user mode VM handle.
2423	* @param uAddrStart The address to start scanning at.
2424	* @param cbScan How much to scan.
2425	*/
2426	static bool dbgDiggerLinuxProbeWithAddr(PDBGDIGGERLINUX pThis, PUVM pUVM, RTGCUINTPTR uAddrStart, size_t cbScan)
2427	{
2428	/*
2429	* Look for "Linux version " at the start of the rodata segment.
2430	* Hope that this comes before any message buffer or other similar string.
2431	*/
2432	DBGFADDRESS KernelAddr;
2433	DBGFR3AddrFromFlat(pUVM, &KernelAddr, uAddrStart);
2434	DBGFADDRESS HitAddr;
2435	int rc = DBGFR3MemScan(pUVM, 0, &KernelAddr, cbScan, 1,
2436	g_abLinuxVersion, sizeof(g_abLinuxVersion) - 1, &HitAddr);
2437	if (RT_SUCCESS(rc))
2438	{
2439	char szTmp[128];
2440	char const *pszX = &szTmp[sizeof(g_abLinuxVersion) - 1];
2441	rc = DBGFR3MemReadString(pUVM, 0, &HitAddr, szTmp, sizeof(szTmp));
2442	if ( RT_SUCCESS(rc)
2443	&& ( ( pszX[0] == '2' /* 2.x.y with x in {0..6} */
2444	&& pszX[1] == '.'
2445	&& pszX[2] >= '0'
2446	&& pszX[2] <= '6')
2447	\|\| ( pszX[0] >= '3' /* 3.x, 4.x, ... 9.x */
2448	&& pszX[0] <= '9'
2449	&& pszX[1] == '.'
2450	&& pszX[2] >= '0'
2451	&& pszX[2] <= '9')
2452	)
2453	)
2454	{
2455	pThis->AddrKernelBase = KernelAddr;
2456	pThis->AddrLinuxBanner = HitAddr;
2457	return true;
2458	}
2459	}
2460
2461	return false;
2462	}
2463
2464	/**
2465	* Probes for a Linux kernel which has KASLR enabled.
2466	*
2467	* @returns Flag whether a possible candidate location was found.
2468	* @param pThis The Linux digger data.
2469	* @param pUVM The user mode VM handle.
2470	* @param uAddrKernelStart The first address the kernel is expected at.
2471	*/
2472	static bool dbgDiggerLinuxProbeKaslr(PDBGDIGGERLINUX pThis, PUVM pUVM, RTGCUINTPTR uAddrKernelStart)
2473	{
2474	/**
2475	* With KASLR the kernel is loaded at a different address at each boot making detection
2476	* more difficult for us.
2477	*
2478	* The randomization is done in arch/x86/boot/compressed/kaslr.c:choose_random_location() (as of Nov 2017).
2479	* At the end of the method a random offset is chosen using find_random_virt_addr() which is added to the
2480	* kernel map start in the caller (the start of the kernel depends on the bit size, see LNX32_KERNEL_ADDRESS_START
2481	* and LNX64_KERNEL_ADDRESS_START for 32bit and 64bit kernels respectively).
2482	* The lowest offset possible is LOAD_PHYSICAL_ADDR which is defined in arch/x86/include/asm/boot.h
2483	* using CONFIG_PHYSICAL_START aligned to CONFIG_PHYSICAL_ALIGN.
2484	* The default CONFIG_PHYSICAL_START and CONFIG_PHYSICAL_ALIGN are both 0x1000000 no matter whether a 32bit
2485	* or a 64bit kernel is used. So the lowest offset to the kernel start address is 0x1000000.
2486	* The find_random_virt_addr() the number of possible slots where the kernel can be placed based on the image size
2487	* is calculated using the following formula:
2488	* cSlots = ((KERNEL_IMAGE_SIZE - 0x1000000 (minimum) - image_size) / 0x1000000 (CONFIG_PHYSICAL_ALIGN)) + 1
2489	*
2490	* KERNEL_IMAGE_SIZE is 1GB for 64bit kernels and 512MB for 32bit kernels, so the maximum number of slots (resulting
2491	* in the largest possible offset) can be achieved when image_size (which contains the real size of the kernel image
2492	* which is unknown for us) goes to 0 and a 1GB KERNEL_IMAGE_SIZE is assumed. With that the biggest cSlots which can be
2493	* achieved is 64. The chosen random offset is taken from a random long integer using kaslr_get_random_long() modulo the
2494	* number of slots which selects a slot between 0 and 63. The final offset is calculated using:
2495	* offAddr = random_addr * 0x1000000 (CONFIG_PHYSICAL_ALIGN) + 0x1000000 (minimum)
2496	*
2497	* So the highest offset the kernel can start is 0x40000000 which is 1GB (plus the maximum kernel size we defined).
2498	*/
2499	if (dbgDiggerLinuxProbeWithAddr(pThis, pUVM, uAddrKernelStart, _1G + LNX_MAX_KERNEL_SIZE))
2500	return true;
2501
2502	return false;
2503	}
2504
2505	/**
2506	* @copydoc DBGFOSREG::pfnInit
2507	*/
2508	static DECLCALLBACK(int) dbgDiggerLinuxInit(PUVM pUVM, void *pvData)
2509	{
2510	PDBGDIGGERLINUX pThis = (PDBGDIGGERLINUX)pvData;
2511	Assert(!pThis->fValid);
2512
2513	/*
2514	* Assume 64-bit kernels all live way beyond 32-bit address space.
2515	*/
2516	pThis->f64Bit = pThis->AddrLinuxBanner.FlatPtr > UINT32_MAX;
2517	pThis->fRelKrnlAddr = false;
2518
2519	pThis->hCfgDb = NULL;
2520
2521	/*
2522	* Try to find the compressed kernel config and parse it before we try
2523	* to get the symbol table, the config database is required to select
2524	* the method to use.
2525	*/
2526	int rc = dbgDiggerLinuxCfgFind(pThis, pUVM);
2527	if (RT_FAILURE(rc))
2528	LogFlowFunc(("Failed to find kernel config (%Rrc), no config database available\n", rc));
2529
2530	static const uint8_t s_abNeedle[] = "kobj";
2531	rc = dbgDiggerLinuxFindSymbolTableFromNeedle(pThis, pUVM, s_abNeedle, sizeof(s_abNeedle) - 1);
2532	if (RT_FAILURE(rc))
2533	{
2534	/* Try alternate needle (seen on older x86 Linux kernels). */
2535	static const uint8_t s_abNeedleAlt[] = "kobjec";
2536	rc = dbgDiggerLinuxFindSymbolTableFromNeedle(pThis, pUVM, s_abNeedleAlt, sizeof(s_abNeedleAlt) - 1);
2537	if (RT_FAILURE(rc))
2538	{
2539	static const uint8_t s_abNeedleOSuseX86[] = "nmi"; /* OpenSuSe 10.2 x86 */
2540	rc = dbgDiggerLinuxFindSymbolTableFromNeedle(pThis, pUVM, s_abNeedleOSuseX86, sizeof(s_abNeedleOSuseX86) - 1);
2541	}
2542	}
2543
2544	pThis->fValid = true;
2545	return VINF_SUCCESS;
2546	}
2547
2548
2549	/**
2550	* @copydoc DBGFOSREG::pfnProbe
2551	*/
2552	static DECLCALLBACK(bool) dbgDiggerLinuxProbe(PUVM pUVM, void *pvData)
2553	{
2554	PDBGDIGGERLINUX pThis = (PDBGDIGGERLINUX)pvData;
2555
2556	for (unsigned i = 0; i < RT_ELEMENTS(g_au64LnxKernelAddresses); i++)
2557	{
2558	if (dbgDiggerLinuxProbeWithAddr(pThis, pUVM, g_au64LnxKernelAddresses[i], LNX_MAX_KERNEL_SIZE))
2559	return true;
2560	}
2561
2562	/* Maybe the kernel uses KASLR. */
2563	if (dbgDiggerLinuxProbeKaslr(pThis, pUVM, LNX32_KERNEL_ADDRESS_START))
2564	return true;
2565
2566	if (dbgDiggerLinuxProbeKaslr(pThis, pUVM, LNX64_KERNEL_ADDRESS_START))
2567	return true;
2568
2569	return false;
2570	}
2571
2572
2573	/**
2574	* @copydoc DBGFOSREG::pfnDestruct
2575	*/
2576	static DECLCALLBACK(void) dbgDiggerLinuxDestruct(PUVM pUVM, void *pvData)
2577	{
2578	RT_NOREF2(pUVM, pvData);
2579	}
2580
2581
2582	/**
2583	* @copydoc DBGFOSREG::pfnConstruct
2584	*/
2585	static DECLCALLBACK(int) dbgDiggerLinuxConstruct(PUVM pUVM, void *pvData)
2586	{
2587	RT_NOREF1(pUVM);
2588	PDBGDIGGERLINUX pThis = (PDBGDIGGERLINUX)pvData;
2589	pThis->IDmesg.u32Magic = DBGFOSIDMESG_MAGIC;
2590	pThis->IDmesg.pfnQueryKernelLog = dbgDiggerLinuxIDmsg_QueryKernelLog;
2591	pThis->IDmesg.u32EndMagic = DBGFOSIDMESG_MAGIC;
2592
2593	return VINF_SUCCESS;
2594	}
2595
2596
2597	const DBGFOSREG g_DBGDiggerLinux =
2598	{
2599	/* .u32Magic = */ DBGFOSREG_MAGIC,
2600	/* .fFlags = */ 0,
2601	/* .cbData = */ sizeof(DBGDIGGERLINUX),
2602	/* .szName = */ "Linux",
2603	/* .pfnConstruct = */ dbgDiggerLinuxConstruct,
2604	/* .pfnDestruct = */ dbgDiggerLinuxDestruct,
2605	/* .pfnProbe = */ dbgDiggerLinuxProbe,
2606	/* .pfnInit = */ dbgDiggerLinuxInit,
2607	/* .pfnRefresh = */ dbgDiggerLinuxRefresh,
2608	/* .pfnTerm = */ dbgDiggerLinuxTerm,
2609	/* .pfnQueryVersion = */ dbgDiggerLinuxQueryVersion,
2610	/* .pfnQueryInterface = */ dbgDiggerLinuxQueryInterface,
2611	/* .u32EndMagic = */ DBGFOSREG_MAGIC
2612	};
2613

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source: vbox/trunk/src/VBox/Debugger/DBGPlugInLinux.cpp@ 71930

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