ldrELFRelocatable.cpp.h@ 45968

Last change on this file since 45968 was 45968, checked in by vboxsync, 12 years ago
Ldr,Dbg: DWARF and ELF hacking in progress.
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1	/* $Id: ldrELFRelocatable.cpp.h 45968 2013-05-09 17:12:13Z vboxsync $ */
2	/** @file
3	* IPRT - Binary Image Loader, Template for ELF Relocatable Images.
4	*/
5
6	/*
7	* Copyright (C) 2006-2012 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.215389.xyz. 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	* The contents of this file may alternatively be used under the terms
18	* of the Common Development and Distribution License Version 1.0
19	* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20	* VirtualBox OSE distribution, in which case the provisions of the
21	* CDDL are applicable instead of those of the GPL.
22	*
23	* You may elect to license modified versions of this file under the
24	* terms and conditions of either the GPL or the CDDL or both.
25	*/
26
27
28	/*******************************************************************************
29	* Defined Constants And Macros *
30	*******************************************************************************/
31	#if ELF_MODE == 32
32	#define RTLDRELF_NAME(name) rtldrELF32##name
33	#define RTLDRELF_SUFF(name) name##32
34	#define RTLDRELF_MID(pre,suff) pre##32##suff
35	#define FMT_ELF_ADDR "%08RX32"
36	#define FMT_ELF_HALF "%04RX16"
37	#define FMT_ELF_OFF "%08RX32"
38	#define FMT_ELF_SIZE "%08RX32"
39	#define FMT_ELF_SWORD "%RI32"
40	#define FMT_ELF_WORD "%08RX32"
41	#define FMT_ELF_XWORD "%08RX32"
42	#define FMT_ELF_SXWORD "%RI32"
43
44	#elif ELF_MODE == 64
45	#define RTLDRELF_NAME(name) rtldrELF64##name
46	#define RTLDRELF_SUFF(name) name##64
47	#define RTLDRELF_MID(pre,suff) pre##64##suff
48	#define FMT_ELF_ADDR "%016RX64"
49	#define FMT_ELF_HALF "%04RX16"
50	#define FMT_ELF_SHALF "%RI16"
51	#define FMT_ELF_OFF "%016RX64"
52	#define FMT_ELF_SIZE "%016RX64"
53	#define FMT_ELF_SWORD "%RI32"
54	#define FMT_ELF_WORD "%08RX32"
55	#define FMT_ELF_XWORD "%016RX64"
56	#define FMT_ELF_SXWORD "%RI64"
57	#endif
58
59	#define Elf_Ehdr RTLDRELF_MID(Elf,_Ehdr)
60	#define Elf_Phdr RTLDRELF_MID(Elf,_Phdr)
61	#define Elf_Shdr RTLDRELF_MID(Elf,_Shdr)
62	#define Elf_Sym RTLDRELF_MID(Elf,_Sym)
63	#define Elf_Rel RTLDRELF_MID(Elf,_Rel)
64	#define Elf_Rela RTLDRELF_MID(Elf,_Rela)
65	#define Elf_Nhdr RTLDRELF_MID(Elf,_Nhdr)
66	#define Elf_Dyn RTLDRELF_MID(Elf,_Dyn)
67	#define Elf_Addr RTLDRELF_MID(Elf,_Addr)
68	#define Elf_Half RTLDRELF_MID(Elf,_Half)
69	#define Elf_Off RTLDRELF_MID(Elf,_Off)
70	#define Elf_Size RTLDRELF_MID(Elf,_Size)
71	#define Elf_Sword RTLDRELF_MID(Elf,_Sword)
72	#define Elf_Word RTLDRELF_MID(Elf,_Word)
73
74	#define RTLDRMODELF RTLDRELF_MID(RTLDRMODELF,RT_NOTHING)
75	#define PRTLDRMODELF RTLDRELF_MID(PRTLDRMODELF,RT_NOTHING)
76
77	#define ELF_R_SYM(info) RTLDRELF_MID(ELF,_R_SYM)(info)
78	#define ELF_R_TYPE(info) RTLDRELF_MID(ELF,_R_TYPE)(info)
79	#define ELF_R_INFO(sym, type) RTLDRELF_MID(ELF,_R_INFO)(sym, type)
80
81	#define ELF_ST_BIND(info) RTLDRELF_MID(ELF,_ST_BIND)(info)
82
83
84
85	/*******************************************************************************
86	* Structures and Typedefs *
87	*******************************************************************************/
88	/**
89	* The ELF loader structure.
90	*/
91	typedef struct RTLDRMODELF
92	{
93	/** Core module structure. */
94	RTLDRMODINTERNAL Core;
95	/** Pointer to the reader instance. */
96	PRTLDRREADER pReader;
97	/** Pointer to readonly mapping of the image bits.
98	* This mapping is provided by the pReader. */
99	const void *pvBits;
100
101	/** The ELF header. */
102	Elf_Ehdr Ehdr;
103	/** Pointer to our copy of the section headers.
104	* The virtual addresses in this array is the 0 based assignments we've given the image.
105	* Not valid if the image is DONE. */
106	Elf_Shdr *paShdrs;
107	/** Unmodified section headers (allocated after paShdrs, so no need to free).
108	* Not valid if the image is DONE. */
109	Elf_Shdr const *paOrgShdrs;
110	/** The size of the loaded image. */
111	size_t cbImage;
112
113	/** The symbol section index. */
114	unsigned iSymSh;
115	/** Number of symbols in the table. */
116	unsigned cSyms;
117	/** Pointer to symbol table within RTLDRMODELF::pvBits. */
118	const Elf_Sym *paSyms;
119
120	/** The string section index. */
121	unsigned iStrSh;
122	/** Size of the string table. */
123	unsigned cbStr;
124	/** Pointer to string table within RTLDRMODELF::pvBits. */
125	const char *pStr;
126	} RTLDRMODELF, *PRTLDRMODELF;
127
128
129	/**
130	* Maps the image bits into memory and resolve pointers into it.
131	*
132	* @returns iprt status code.
133	* @param pModElf The ELF loader module instance data.
134	* @param fNeedsBits Set if we actually need the pvBits member.
135	* If we don't, we can simply read the string and symbol sections, thus saving memory.
136	*/
137	static int RTLDRELF_NAME(MapBits)(PRTLDRMODELF pModElf, bool fNeedsBits)
138	{
139	NOREF(fNeedsBits);
140	if (pModElf->pvBits)
141	return VINF_SUCCESS;
142	int rc = pModElf->pReader->pfnMap(pModElf->pReader, &pModElf->pvBits);
143	if (RT_SUCCESS(rc))
144	{
145	const uint8_t pu8 = (const uint8_t )pModElf->pvBits;
146	if (pModElf->iSymSh != ~0U)
147	pModElf->paSyms = (const Elf_Sym *)(pu8 + pModElf->paShdrs[pModElf->iSymSh].sh_offset);
148	if (pModElf->iStrSh != ~0U)
149	pModElf->pStr = (const char *)(pu8 + pModElf->paShdrs[pModElf->iStrSh].sh_offset);
150	}
151	return rc;
152	}
153
154
155	/**
156	* Get the symbol and symbol value.
157	*
158	* @returns iprt status code.
159	* @param pModElf The ELF loader module instance data.
160	* @param BaseAddr The base address which the module is being fixedup to.
161	* @param pfnGetImport The callback function to use to resolve imports (aka unresolved externals).
162	* @param pvUser User argument to pass to the callback.
163	* @param iSym The symbol to get.
164	* @param ppSym Where to store the symbol pointer on success. (read only)
165	* @param pSymValue Where to store the symbol value on success.
166	*/
167	static int RTLDRELF_NAME(Symbol)(PRTLDRMODELF pModElf, Elf_Addr BaseAddr, PFNRTLDRIMPORT pfnGetImport, void *pvUser,
168	Elf_Size iSym, const Elf_Sym *ppSym, Elf_Addr pSymValue)
169	{
170	/*
171	* Validate and find the symbol.
172	*/
173	if (iSym >= pModElf->cSyms)
174	{
175	AssertMsgFailed(("iSym=%d is an invalid symbol index!\n", iSym));
176	return VERR_LDRELF_INVALID_SYMBOL_INDEX;
177	}
178	const Elf_Sym *pSym = &pModElf->paSyms[iSym];
179	*ppSym = pSym;
180
181	if (pSym->st_name >= pModElf->cbStr)
182	{
183	AssertMsgFailed(("iSym=%d st_name=%d str sh_size=%d\n", iSym, pSym->st_name, pModElf->cbStr));
184	return VERR_LDRELF_INVALID_SYMBOL_NAME_OFFSET;
185	}
186	const char *pszName = ELF_STR(pModElf, pSym->st_name);
187
188	/*
189	* Determine the symbol value.
190	*
191	* Symbols needs different treatment depending on which section their are in.
192	* Undefined and absolute symbols goes into special non-existing sections.
193	*/
194	switch (pSym->st_shndx)
195	{
196	/*
197	* Undefined symbol, needs resolving.
198	*
199	* Since ELF has no generic concept of importing from specific module (the OS/2 ELF format
200	* has but that's a OS extension and only applies to programs and dlls), we'll have to ask
201	* the resolver callback to do a global search.
202	*/
203	case SHN_UNDEF:
204	{
205	/* Try to resolve the symbol. */
206	RTUINTPTR Value;
207	int rc = pfnGetImport(&pModElf->Core, "", pszName, ~0, &Value, pvUser);
208	if (RT_FAILURE(rc))
209	{
210	AssertMsgFailed(("Failed to resolve '%s' rc=%Rrc\n", pszName, rc));
211	return rc;
212	}
213	*pSymValue = (Elf_Addr)Value;
214	if ((RTUINTPTR)*pSymValue != Value)
215	{
216	AssertMsgFailed(("Symbol value overflowed! '%s'\n", pszName));
217	return VERR_SYMBOL_VALUE_TOO_BIG;
218	}
219
220	Log2(("rtldrELF: #%-3d - UNDEF " FMT_ELF_ADDR " '%s'\n", iSym, *pSymValue, pszName));
221	break;
222	}
223
224	/*
225	* Absolute symbols needs no fixing since they are, well, absolute.
226	*/
227	case SHN_ABS:
228	*pSymValue = pSym->st_value;
229	Log2(("rtldrELF: #%-3d - ABS " FMT_ELF_ADDR " '%s'\n", iSym, *pSymValue, pszName));
230	break;
231
232	/*
233	* All other symbols are addressed relative to their section and need to be fixed up.
234	*/
235	default:
236	if (pSym->st_shndx >= pModElf->Ehdr.e_shnum)
237	{
238	/* what about common symbols? */
239	AssertMsg(pSym->st_shndx < pModElf->Ehdr.e_shnum,
240	("iSym=%d st_shndx=%d e_shnum=%d pszName=%s\n", iSym, pSym->st_shndx, pModElf->Ehdr.e_shnum, pszName));
241	return VERR_BAD_EXE_FORMAT;
242	}
243	*pSymValue = pSym->st_value + pModElf->paShdrs[pSym->st_shndx].sh_addr + BaseAddr;
244	Log2(("rtldrELF: #%-3d - %5d " FMT_ELF_ADDR " '%s'\n", iSym, pSym->st_shndx, *pSymValue, pszName));
245	break;
246	}
247
248	return VINF_SUCCESS;
249	}
250
251
252	/**
253	* Applies the fixups for a sections.
254	*
255	* @returns iprt status code.
256	* @param pModElf The ELF loader module instance data.
257	* @param BaseAddr The base address which the module is being fixedup to.
258	* @param pfnGetImport The callback function to use to resolve imports (aka unresolved externals).
259	* @param pvUser User argument to pass to the callback.
260	* @param SecAddr The section address. This is the address the relocations are relative to.
261	* @param cbSec The section size. The relocations must be inside this.
262	* @param pu8SecBaseR Where we read section bits from.
263	* @param pu8SecBaseW Where we write section bits to.
264	* @param pvRelocs Pointer to where we read the relocations from.
265	* @param cbRelocs Size of the relocations.
266	*/
267	static int RTLDRELF_NAME(RelocateSection)(PRTLDRMODELF pModElf, Elf_Addr BaseAddr, PFNRTLDRIMPORT pfnGetImport, void *pvUser,
268	const Elf_Addr SecAddr, Elf_Size cbSec, const uint8_t pu8SecBaseR, uint8_t pu8SecBaseW,
269	const void *pvRelocs, Elf_Size cbRelocs)
270	{
271	#if ELF_MODE != 32
272	NOREF(pu8SecBaseR);
273	#endif
274
275	/*
276	* Iterate the relocations.
277	* The relocations are stored in an array of Elf32_Rel records and covers the entire relocation section.
278	*/
279	const Elf_Reloc paRels = (const Elf_Reloc )pvRelocs;
280	const unsigned iRelMax = (unsigned)(cbRelocs / sizeof(paRels[0]));
281	AssertMsgReturn(iRelMax == cbRelocs / sizeof(paRels[0]), (FMT_ELF_SIZE "\n", cbRelocs / sizeof(paRels[0])), VERR_IMAGE_TOO_BIG);
282	for (unsigned iRel = 0; iRel < iRelMax; iRel++)
283	{
284	/*
285	* Get the symbol.
286	*/
287	const Elf_Sym pSym = NULL; / shut up gcc */
288	Elf_Addr SymValue = 0; /* shut up gcc-4 */
289	int rc = RTLDRELF_NAME(Symbol)(pModElf, BaseAddr, pfnGetImport, pvUser, ELF_R_SYM(paRels[iRel].r_info), &pSym, &SymValue);
290	if (RT_FAILURE(rc))
291	return rc;
292
293	Log3(("rtldrELF: " FMT_ELF_ADDR " %02x %06x - " FMT_ELF_ADDR " %3d %02x %s\n",
294	paRels[iRel].r_offset, ELF_R_TYPE(paRels[iRel].r_info), (unsigned)ELF_R_SYM(paRels[iRel].r_info),
295	SymValue, (unsigned)pSym->st_shndx, pSym->st_info, ELF_STR(pModElf, pSym->st_name)));
296
297	/*
298	* Apply the fixup.
299	*/
300	AssertMsgReturn(paRels[iRel].r_offset < cbSec, (FMT_ELF_ADDR " " FMT_ELF_SIZE "\n", paRels[iRel].r_offset, cbSec), VERR_LDRELF_INVALID_RELOCATION_OFFSET);
301	#if ELF_MODE == 32
302	const Elf_Addr pAddrR = (const Elf_Addr )(pu8SecBaseR + paRels[iRel].r_offset); /* Where to read the addend. */
303	#endif
304	Elf_Addr pAddrW = (Elf_Addr )(pu8SecBaseW + paRels[iRel].r_offset); /* Where to write the fixup. */
305	switch (ELF_R_TYPE(paRels[iRel].r_info))
306	{
307	#if ELF_MODE == 32
308	/*
309	* Absolute addressing.
310	*/
311	case R_386_32:
312	{
313	const Elf_Addr Value = SymValue + *pAddrR;
314	(uint32_t )pAddrW = Value;
315	Log4((FMT_ELF_ADDR": R_386_32 Value=" FMT_ELF_ADDR " SymValue=" FMT_ELF_ADDR "\n",
316	SecAddr + paRels[iRel].r_offset + BaseAddr, Value, SymValue));
317	break;
318	}
319
320	/*
321	* PC relative addressing.
322	*/
323	case R_386_PC32:
324	{
325	const Elf_Addr SourceAddr = SecAddr + paRels[iRel].r_offset + BaseAddr; /* Where the source really is. */
326	const Elf_Addr Value = SymValue + (uint32_t )pAddrR - SourceAddr;
327	(uint32_t )pAddrW = Value;
328	Log4((FMT_ELF_ADDR": R_386_PC32 Value=" FMT_ELF_ADDR " SymValue=" FMT_ELF_ADDR "\n",
329	SourceAddr, Value, SymValue));
330	break;
331	}
332
333	/* ignore */
334	case R_386_NONE:
335	break;
336
337	#elif ELF_MODE == 64
338
339	/*
340	* Absolute addressing
341	*/
342	case R_X86_64_64:
343	{
344	const Elf_Addr Value = SymValue + paRels[iRel].r_addend;
345	(uint64_t )pAddrW = Value;
346	Log4((FMT_ELF_ADDR": R_X86_64_64 Value=" FMT_ELF_ADDR " SymValue=" FMT_ELF_ADDR "\n",
347	SecAddr + paRels[iRel].r_offset + BaseAddr, Value, SymValue));
348	break;
349	}
350
351	/*
352	* Truncated 32-bit value (zero-extendedable to the 64-bit value).
353	*/
354	case R_X86_64_32:
355	{
356	const Elf_Addr Value = SymValue + paRels[iRel].r_addend;
357	(uint32_t )pAddrW = (uint32_t)Value;
358	Log4((FMT_ELF_ADDR": R_X86_64_32 Value=" FMT_ELF_ADDR " SymValue=" FMT_ELF_ADDR "\n",
359	SecAddr + paRels[iRel].r_offset + BaseAddr, Value, SymValue));
360	AssertMsgReturn((Elf_Addr)(uint32_t )pAddrW == Value, ("Value=" FMT_ELF_ADDR "\n", Value), VERR_SYMBOL_VALUE_TOO_BIG);
361	break;
362	}
363
364	/*
365	* Truncated 32-bit value (sign-extendedable to the 64-bit value).
366	*/
367	case R_X86_64_32S:
368	{
369	const Elf_Addr Value = SymValue + paRels[iRel].r_addend;
370	(int32_t )pAddrW = (int32_t)Value;
371	Log4((FMT_ELF_ADDR": R_X86_64_32S Value=" FMT_ELF_ADDR " SymValue=" FMT_ELF_ADDR "\n",
372	SecAddr + paRels[iRel].r_offset + BaseAddr, Value, SymValue));
373	AssertMsgReturn((Elf_Addr)(int32_t )pAddrW == Value, ("Value=" FMT_ELF_ADDR "\n", Value), VERR_SYMBOL_VALUE_TOO_BIG); /** @todo check the sign-extending here. */
374	break;
375	}
376
377	/*
378	* PC relative addressing.
379	*/
380	case R_X86_64_PC32:
381	{
382	const Elf_Addr SourceAddr = SecAddr + paRels[iRel].r_offset + BaseAddr; /* Where the source really is. */
383	const Elf_Addr Value = SymValue + paRels[iRel].r_addend - SourceAddr;
384	(int32_t )pAddrW = (int32_t)Value;
385	Log4((FMT_ELF_ADDR": R_X86_64_PC32 Value=" FMT_ELF_ADDR " SymValue=" FMT_ELF_ADDR "\n",
386	SourceAddr, Value, SymValue));
387	AssertMsgReturn((Elf_Addr)(int32_t )pAddrW == Value, ("Value=" FMT_ELF_ADDR "\n", Value), VERR_SYMBOL_VALUE_TOO_BIG); /** @todo check the sign-extending here. */
388	break;
389	}
390
391	/* ignore */
392	case R_X86_64_NONE:
393	break;
394	#endif
395
396	default:
397	AssertMsgFailed(("Unknown relocation type: %d (iRel=%d iRelMax=%d)\n",
398	ELF_R_TYPE(paRels[iRel].r_info), iRel, iRelMax));
399	return VERR_LDRELF_RELOCATION_NOT_SUPPORTED;
400	}
401	}
402
403	return VINF_SUCCESS;
404	}
405
406
407
408	/** @copydoc RTLDROPS::pfnClose */
409	static DECLCALLBACK(int) RTLDRELF_NAME(Close)(PRTLDRMODINTERNAL pMod)
410	{
411	PRTLDRMODELF pModElf = (PRTLDRMODELF)pMod;
412
413	if (pModElf->paShdrs)
414	{
415	RTMemFree(pModElf->paShdrs);
416	pModElf->paShdrs = NULL;
417	}
418
419	if (pModElf->pReader)
420	{
421	pModElf->pReader->pfnDestroy(pModElf->pReader);
422	pModElf->pReader = NULL;
423	}
424
425	pModElf->pvBits = NULL;
426
427	return VINF_SUCCESS;
428	}
429
430
431	/** @copydoc RTLDROPS::Done */
432	static DECLCALLBACK(int) RTLDRELF_NAME(Done)(PRTLDRMODINTERNAL pMod)
433	{
434	NOREF(pMod); /PRTLDRMODELF pModElf = (PRTLDRMODELF)pMod;/
435	/** @todo Have to think more about this .... */
436	return -1;
437	}
438
439
440	/** @copydoc RTLDROPS::EnumSymbols */
441	static DECLCALLBACK(int) RTLDRELF_NAME(EnumSymbols)(PRTLDRMODINTERNAL pMod, unsigned fFlags, const void *pvBits, RTUINTPTR BaseAddress,
442	PFNRTLDRENUMSYMS pfnCallback, void *pvUser)
443	{
444	PRTLDRMODELF pModElf = (PRTLDRMODELF)pMod;
445	NOREF(pvBits);
446
447	/*
448	* Validate the input.
449	*/
450	Elf_Addr BaseAddr = (Elf_Addr)BaseAddress;
451	AssertMsgReturn((RTUINTPTR)BaseAddr == BaseAddress, ("#RTptr", BaseAddress), VERR_IMAGE_BASE_TOO_HIGH);
452
453	/*
454	* Make sure we've got the string and symbol tables. (We don't need the pvBits.)
455	*/
456	int rc = RTLDRELF_NAME(MapBits)(pModElf, false);
457	if (RT_FAILURE(rc))
458	return rc;
459
460	/*
461	* Enumerate the symbol table.
462	*/
463	const Elf_Sym *paSyms = pModElf->paSyms;
464	unsigned cSyms = pModElf->cSyms;
465	for (unsigned iSym = 1; iSym < cSyms; iSym++)
466	{
467	/*
468	* Skip imports (undefined).
469	*/
470	if (paSyms[iSym].st_shndx != SHN_UNDEF)
471	{
472	/*
473	* Calc value and get name.
474	*/
475	Elf_Addr Value;
476	if (paSyms[iSym].st_shndx == SHN_ABS)
477	/* absolute symbols are not subject to any relocation. */
478	Value = paSyms[iSym].st_value;
479	else if (paSyms[iSym].st_shndx < pModElf->Ehdr.e_shnum)
480	/* relative to the section. */
481	Value = BaseAddr + paSyms[iSym].st_value + pModElf->paShdrs[paSyms[iSym].st_shndx].sh_addr;
482	else
483	{
484	AssertMsgFailed(("Arg! paSyms[%u].st_shndx=" FMT_ELF_HALF "\n", iSym, paSyms[iSym].st_shndx));
485	return VERR_BAD_EXE_FORMAT;
486	}
487	const char *pszName = ELF_STR(pModElf, paSyms[iSym].st_name);
488	if ( (pszName && *pszName)
489	&& ( (fFlags & RTLDR_ENUM_SYMBOL_FLAGS_ALL)
490	\|\| ELF_ST_BIND(paSyms[iSym].st_info) == STB_GLOBAL)
491	)
492	{
493	/*
494	* Call back.
495	*/
496	AssertMsgReturn(Value == (RTUINTPTR)Value, (FMT_ELF_ADDR "\n", Value), VERR_SYMBOL_VALUE_TOO_BIG);
497	rc = pfnCallback(pMod, pszName, ~0, (RTUINTPTR)Value, pvUser);
498	if (rc)
499	return rc;
500	}
501	}
502	}
503
504	return VINF_SUCCESS;
505	}
506
507
508	/** @copydoc RTLDROPS::GetImageSize */
509	static DECLCALLBACK(size_t) RTLDRELF_NAME(GetImageSize)(PRTLDRMODINTERNAL pMod)
510	{
511	PRTLDRMODELF pModElf = (PRTLDRMODELF)pMod;
512
513	return pModElf->cbImage;
514	}
515
516
517	/** @copydoc RTLDROPS::GetBits */
518	static DECLCALLBACK(int) RTLDRELF_NAME(GetBits)(PRTLDRMODINTERNAL pMod, void pvBits, RTUINTPTR BaseAddress, PFNRTLDRIMPORT pfnGetImport, void pvUser)
519	{
520	PRTLDRMODELF pModElf = (PRTLDRMODELF)pMod;
521
522	/*
523	* This operation is currently only available on relocatable images.
524	*/
525	switch (pModElf->Ehdr.e_type)
526	{
527	case ET_REL:
528	break;
529	case ET_EXEC:
530	Log(("RTLdrELF: %s: Executable images are not supported yet!\n", pModElf->pReader->pfnLogName(pModElf->pReader)));
531	return VERR_LDRELF_EXEC;
532	case ET_DYN:
533	Log(("RTLdrELF: %s: Dynamic images are not supported yet!\n", pModElf->pReader->pfnLogName(pModElf->pReader)));
534	return VERR_LDRELF_DYN;
535	default: AssertFailedReturn(VERR_BAD_EXE_FORMAT);
536	}
537
538	/*
539	* Load the bits into pvBits.
540	*/
541	const Elf_Shdr *paShdrs = pModElf->paShdrs;
542	for (unsigned iShdr = 0; iShdr < pModElf->Ehdr.e_shnum; iShdr++)
543	{
544	if (paShdrs[iShdr].sh_flags & SHF_ALLOC)
545	{
546	AssertMsgReturn((size_t)paShdrs[iShdr].sh_size == (size_t)paShdrs[iShdr].sh_size, (FMT_ELF_SIZE "\n", paShdrs[iShdr].sh_size), VERR_IMAGE_TOO_BIG);
547	switch (paShdrs[iShdr].sh_type)
548	{
549	case SHT_NOBITS:
550	memset((uint8_t *)pvBits + paShdrs[iShdr].sh_addr, 0, (size_t)paShdrs[iShdr].sh_size);
551	break;
552
553	case SHT_PROGBITS:
554	default:
555	{
556	int rc = pModElf->pReader->pfnRead(pModElf->pReader, (uint8_t *)pvBits + paShdrs[iShdr].sh_addr,
557	(size_t)paShdrs[iShdr].sh_size, paShdrs[iShdr].sh_offset);
558	if (RT_FAILURE(rc))
559	{
560	Log(("RTLdrELF: %s: Read error when reading " FMT_ELF_SIZE " bytes at " FMT_ELF_OFF ", iShdr=%d\n",
561	pModElf->pReader->pfnLogName(pModElf->pReader),
562	paShdrs[iShdr].sh_size, paShdrs[iShdr].sh_offset, iShdr));
563	return rc;
564	}
565	}
566	}
567	}
568	}
569
570	/*
571	* Relocate the image.
572	*/
573	return pModElf->Core.pOps->pfnRelocate(pMod, pvBits, BaseAddress, ~(RTUINTPTR)0, pfnGetImport, pvUser);
574	}
575
576
577	/** @copydoc RTLDROPS::Relocate */
578	static DECLCALLBACK(int) RTLDRELF_NAME(Relocate)(PRTLDRMODINTERNAL pMod, void *pvBits, RTUINTPTR NewBaseAddress,
579	RTUINTPTR OldBaseAddress, PFNRTLDRIMPORT pfnGetImport, void *pvUser)
580	{
581	PRTLDRMODELF pModElf = (PRTLDRMODELF)pMod;
582	#ifdef LOG_ENABLED
583	const char *pszLogName = pModElf->pReader->pfnLogName(pModElf->pReader);
584	#endif
585	NOREF(OldBaseAddress);
586
587	/*
588	* This operation is currently only available on relocatable images.
589	*/
590	switch (pModElf->Ehdr.e_type)
591	{
592	case ET_REL:
593	break;
594	case ET_EXEC:
595	Log(("RTLdrELF: %s: Executable images are not supported yet!\n", pszLogName));
596	return VERR_LDRELF_EXEC;
597	case ET_DYN:
598	Log(("RTLdrELF: %s: Dynamic images are not supported yet!\n", pszLogName));
599	return VERR_LDRELF_DYN;
600	default: AssertFailedReturn(VERR_BAD_EXE_FORMAT);
601	}
602
603	/*
604	* Validate the input.
605	*/
606	Elf_Addr BaseAddr = (Elf_Addr)NewBaseAddress;
607	AssertMsgReturn((RTUINTPTR)BaseAddr == NewBaseAddress, ("#RTptr", NewBaseAddress), VERR_IMAGE_BASE_TOO_HIGH);
608
609	/*
610	* Map the image bits if not already done and setup pointer into it.
611	*/
612	int rc = RTLDRELF_NAME(MapBits)(pModElf, true);
613	if (RT_FAILURE(rc))
614	return rc;
615
616	/*
617	* Iterate the sections looking for interesting SHT_REL[A] sections.
618	* SHT_REL[A] sections have the section index of the section they contain fixups
619	* for in the sh_info member.
620	*/
621	const Elf_Shdr *paShdrs = pModElf->paShdrs;
622	Log2(("rtLdrElf: %s: Fixing up image\n", pszLogName));
623	for (unsigned iShdr = 0; iShdr < pModElf->Ehdr.e_shnum; iShdr++)
624	{
625	const Elf_Shdr *pShdrRel = &paShdrs[iShdr];
626
627	/*
628	* Skip sections without interest to us.
629	*/
630	#if ELF_MODE == 32
631	if (pShdrRel->sh_type != SHT_REL)
632	#else
633	if (pShdrRel->sh_type != SHT_RELA)
634	#endif
635	continue;
636	if (pShdrRel->sh_info >= pModElf->Ehdr.e_shnum)
637	continue;
638	const Elf_Shdr pShdr = &paShdrs[pShdrRel->sh_info]; / the section to fixup. */
639	if (!(pShdr->sh_flags & SHF_ALLOC))
640	continue;
641
642	/*
643	* Relocate the section.
644	*/
645	Log2(("rtldrELF: %s: Relocation records for #%d [%s] (sh_info=%d sh_link=%d) found in #%d [%s] (sh_info=%d sh_link=%d)\n",
646	pszLogName, (int)pShdrRel->sh_info, ELF_STR(pModElf, pShdr->sh_name), (int)pShdr->sh_info, (int)pShdr->sh_link,
647	iShdr, ELF_STR(pModElf, pShdrRel->sh_name), (int)pShdrRel->sh_info, (int)pShdrRel->sh_link));
648
649	/** @todo Make RelocateSection a function pointer so we can select the one corresponding to the machine when opening the image. */
650	rc = RTLDRELF_NAME(RelocateSection)(pModElf, BaseAddr, pfnGetImport, pvUser,
651	pShdr->sh_addr,
652	pShdr->sh_size,
653	(const uint8_t *)pModElf->pvBits + pShdr->sh_offset,
654	(uint8_t *)pvBits + pShdr->sh_addr,
655	(const uint8_t *)pModElf->pvBits + pShdrRel->sh_offset,
656	pShdrRel->sh_size);
657	if (RT_FAILURE(rc))
658	return rc;
659	}
660	return VINF_SUCCESS;
661	}
662
663
664	/** @copydoc RTLDROPS::pfnGetSymbolEx */
665	static DECLCALLBACK(int) RTLDRELF_NAME(GetSymbolEx)(PRTLDRMODINTERNAL pMod, const void pvBits, RTUINTPTR BaseAddress, const char pszSymbol, RTUINTPTR *pValue)
666	{
667	PRTLDRMODELF pModElf = (PRTLDRMODELF)pMod;
668	NOREF(pvBits);
669
670	/*
671	* Validate the input.
672	*/
673	Elf_Addr BaseAddr = (Elf_Addr)BaseAddress;
674	AssertMsgReturn((RTUINTPTR)BaseAddr == BaseAddress, ("#RTptr", BaseAddress), VERR_IMAGE_BASE_TOO_HIGH);
675
676	/*
677	* Map the image bits if not already done and setup pointer into it.
678	*/
679	int rc = RTLDRELF_NAME(MapBits)(pModElf, true);
680	if (RT_FAILURE(rc))
681	return rc;
682
683	/*
684	* Calc all kinds of pointers before we start iterating the symbol table.
685	*/
686	const char *pStr = pModElf->pStr;
687	const Elf_Sym *paSyms = pModElf->paSyms;
688	unsigned cSyms = pModElf->cSyms;
689	for (unsigned iSym = 1; iSym < cSyms; iSym++)
690	{
691	/* Undefined symbols are not exports, they are imports. */
692	if ( paSyms[iSym].st_shndx != SHN_UNDEF
693	&& ( ELF_ST_BIND(paSyms[iSym].st_info) == STB_GLOBAL
694	\|\| ELF_ST_BIND(paSyms[iSym].st_info) == STB_WEAK))
695	{
696	/* Validate the name string and try match with it. */
697	if (paSyms[iSym].st_name < pModElf->cbStr)
698	{
699	if (!strcmp(pszSymbol, pStr + paSyms[iSym].st_name))
700	{
701	/* matched! */
702	Elf_Addr Value;
703	if (paSyms[iSym].st_shndx == SHN_ABS)
704	/* absolute symbols are not subject to any relocation. */
705	Value = paSyms[iSym].st_value;
706	else if (paSyms[iSym].st_shndx < pModElf->Ehdr.e_shnum)
707	/* relative to the section. */
708	Value = BaseAddr + paSyms[iSym].st_value + pModElf->paShdrs[paSyms[iSym].st_shndx].sh_addr;
709	else
710	{
711	AssertMsgFailed(("Arg. paSyms[iSym].st_shndx=%d\n", paSyms[iSym].st_shndx));
712	return VERR_BAD_EXE_FORMAT;
713	}
714	AssertMsgReturn(Value == (RTUINTPTR)Value, (FMT_ELF_ADDR "\n", Value), VERR_SYMBOL_VALUE_TOO_BIG);
715	*pValue = (RTUINTPTR)Value;
716	return VINF_SUCCESS;
717	}
718	}
719	else
720	{
721	AssertMsgFailed(("String outside string table! iSym=%d paSyms[iSym].st_name=%#x\n", iSym, paSyms[iSym].st_name));
722	return VERR_LDRELF_INVALID_SYMBOL_NAME_OFFSET;
723	}
724	}
725	}
726
727	return VERR_SYMBOL_NOT_FOUND;
728	}
729
730
731	/** @copydoc RTLDROPS::pfnEnumDbgInfo */
732	static DECLCALLBACK(int) RTLDRELF_NAME(EnumDbgInfo)(PRTLDRMODINTERNAL pMod, const void *pvBits,
733	PFNRTLDRENUMDBG pfnCallback, void *pvUser)
734	{
735	PRTLDRMODELF pModElf = (PRTLDRMODELF)pMod;
736
737	/*
738	* Map the image bits if not already done and setup pointer into it.
739	*/
740	int rc = RTLDRELF_NAME(MapBits)(pModElf, true);
741	if (RT_FAILURE(rc))
742	return rc;
743
744	/*
745	* Do the enumeration.
746	*/
747	const Elf_Shdr *paShdrs = pModElf->paOrgShdrs;
748	for (unsigned iShdr = 0; iShdr < pModElf->Ehdr.e_shnum; iShdr++)
749	{
750	/* Debug sections are expected to be PROGBITS and not allocated. */
751	if (paShdrs[iShdr].sh_type != SHT_PROGBITS)
752	continue;
753	if (paShdrs[iShdr].sh_flags & SHF_ALLOC)
754	continue;
755
756	const char *pszSectName = ELF_STR(pModElf, paShdrs[iShdr].sh_name);
757	if ( !strncmp(pszSectName, RT_STR_TUPLE(".debug_"))
758	\|\| !strcmp(pszSectName, ".WATCOM_references") )
759	{
760	int rc = pfnCallback(pMod, iShdr - 1, RTLDRDBGINFOTYPE_DWARF, 0, 0, pszSectName,
761	paShdrs[iShdr].sh_offset,
762	paShdrs[iShdr].sh_addr,
763	paShdrs[iShdr].sh_size,
764	NULL, pvUser);
765	if (rc != VINF_SUCCESS)
766	return rc;
767	}
768	else if (!strcmp(pszSectName, ".gnu_debuglink"))
769	{
770	if ((paShdrs[iShdr].sh_size & 3) \|\| paShdrs[iShdr].sh_size < 8)
771	return VERR_BAD_EXE_FORMAT;
772	const char pszExtFile = (const char )((uintptr_t)pModElf->pvBits + paShdrs[iShdr].sh_offset);
773	if (!RTStrEnd(pszExtFile, paShdrs[iShdr].sh_size))
774	return VERR_BAD_EXE_FORMAT;
775
776	uint32_t uCrc32 = (uint32_t )((uintptr_t)pszExtFile + paShdrs[iShdr].sh_size - sizeof(uint32_t));
777	char szCrc32[16];
778	RTStrPrintf(szCrc32, sizeof(szCrc32), "%#010x", uCrc32);
779
780	int rc = pfnCallback(pMod, iShdr - 1, RTLDRDBGINFOTYPE_DWARF, 0, 0, szCrc32,
781	paShdrs[iShdr].sh_offset,
782	paShdrs[iShdr].sh_addr,
783	paShdrs[iShdr].sh_size,
784	pszExtFile, pvUser);
785	if (rc != VINF_SUCCESS)
786	return rc;
787	}
788	}
789
790	return VINF_SUCCESS;
791	}
792
793
794	/**
795	* Helper that locates the first allocated section.
796	*
797	* @returns Pointer to the section header if found, NULL if none.
798	* @param pShdr The section header to start searching at.
799	* @param cLeft The number of section headers left to search. Can be 0.
800	*/
801	static const Elf_Shdr RTLDRELF_NAME(GetFirstAllocatedSection)(const Elf_Shdr pShdr, unsigned cLeft)
802	{
803	while (cLeft-- > 0)
804	{
805	if (pShdr->sh_flags & SHF_ALLOC)
806	return pShdr;
807	pShdr++;
808	}
809	return NULL;
810	}
811
812	/** @copydoc RTLDROPS::pfnEnumSegments. */
813	static DECLCALLBACK(int) RTLDRELF_NAME(EnumSegments)(PRTLDRMODINTERNAL pMod, PFNRTLDRENUMSEGS pfnCallback, void *pvUser)
814	{
815	PRTLDRMODELF pModElf = (PRTLDRMODELF)pMod;
816
817	/*
818	* Map the image bits if not already done and setup pointer into it.
819	*/
820	int rc = RTLDRELF_NAME(MapBits)(pModElf, true);
821	if (RT_FAILURE(rc))
822	return rc;
823
824	/*
825	* Do the enumeration.
826	*/
827	const Elf_Shdr *paShdrs = pModElf->paShdrs;
828	const Elf_Shdr *paOrgShdrs = pModElf->paOrgShdrs;
829	for (unsigned iShdr = 1; iShdr < pModElf->Ehdr.e_shnum; iShdr++)
830	{
831	RTLDRSEG Seg;
832	Seg.pchName = ELF_STR(pModElf, paShdrs[iShdr].sh_name);
833	Seg.cchName = (uint32_t)strlen(Seg.pchName);
834	Seg.SelFlat = 0;
835	Seg.Sel16bit = 0;
836	Seg.fFlags = 0;
837	Seg.fProt = RTMEM_PROT_READ;
838	if (paShdrs[iShdr].sh_flags & SHF_WRITE)
839	Seg.fProt \|= RTMEM_PROT_WRITE;
840	if (paShdrs[iShdr].sh_flags & SHF_EXECINSTR)
841	Seg.fProt \|= RTMEM_PROT_EXEC;
842	Seg.cb = paShdrs[iShdr].sh_size;
843	Seg.Alignment = paShdrs[iShdr].sh_addralign;
844	if (paShdrs[iShdr].sh_flags & SHF_ALLOC)
845	{
846	Seg.LinkAddress = paOrgShdrs[iShdr].sh_addr;
847	Seg.RVA = paShdrs[iShdr].sh_addr;
848	const Elf_Shdr *pShdr2 = RTLDRELF_NAME(GetFirstAllocatedSection)(&paShdrs[iShdr + 1],
849	pModElf->Ehdr.e_shnum - iShdr - 1);
850	Seg.cbMapped = pShdr2 ? pShdr2->sh_addr - paShdrs[iShdr].sh_addr : paShdrs[iShdr].sh_size;
851	}
852	else
853	{
854	Seg.LinkAddress = NIL_RTLDRADDR;
855	Seg.RVA = NIL_RTLDRADDR;
856	Seg.cbMapped = NIL_RTLDRADDR;
857	}
858	if (paShdrs[iShdr].sh_type != SHT_NOBITS)
859	{
860	Seg.offFile = paShdrs[iShdr].sh_offset;
861	Seg.cbFile = paShdrs[iShdr].sh_size;
862	}
863	else
864	{
865	Seg.offFile = -1;
866	Seg.cbFile = 0;
867	}
868
869	int rc = pfnCallback(pMod, &Seg, pvUser);
870	if (rc != VINF_SUCCESS)
871	return rc;
872	}
873
874	return VINF_SUCCESS;
875	}
876
877
878	/** @copydoc RTLDROPS::pfnLinkAddressToSegOffset. */
879	static DECLCALLBACK(int) RTLDRELF_NAME(LinkAddressToSegOffset)(PRTLDRMODINTERNAL pMod, RTLDRADDR LinkAddress,
880	uint32_t *piSeg, PRTLDRADDR poffSeg)
881	{
882	PRTLDRMODELF pModElf = (PRTLDRMODELF)pMod;
883
884	const Elf_Shdr *pShdrEnd = NULL;
885	unsigned cLeft = pModElf->Ehdr.e_shnum - 1;
886	const Elf_Shdr *pShdr = &pModElf->paOrgShdrs[cLeft];
887	while (cLeft-- > 0)
888	{
889	pShdr--;
890	if (pShdr->sh_flags & SHF_ALLOC)
891	{
892	RTLDRADDR offSeg = LinkAddress - pShdr->sh_addr;
893	if (offSeg < pShdr->sh_size)
894	{
895	*poffSeg = offSeg;
896	*piSeg = cLeft;
897	return VINF_SUCCESS;
898	}
899	if (offSeg == pShdr->sh_size)
900	pShdrEnd = pShdr;
901	}
902	}
903
904	if (pShdrEnd)
905	{
906	*poffSeg = pShdrEnd->sh_size;
907	*piSeg = pShdrEnd - pModElf->paOrgShdrs - 1;
908	return VINF_SUCCESS;
909	}
910
911	return VERR_LDR_INVALID_LINK_ADDRESS;
912	}
913
914
915	/** @copydoc RTLDROPS::pfnLinkAddressToRva. */
916	static DECLCALLBACK(int) RTLDRELF_NAME(LinkAddressToRva)(PRTLDRMODINTERNAL pMod, RTLDRADDR LinkAddress, PRTLDRADDR pRva)
917	{
918	PRTLDRMODELF pModElf = (PRTLDRMODELF)pMod;
919	uint32_t iSeg;
920	RTLDRADDR offSeg;
921	int rc = RTLDRELF_NAME(LinkAddressToSegOffset)(pMod, LinkAddress, &iSeg, &offSeg);
922	if (RT_SUCCESS(rc))
923	*pRva = pModElf->paShdrs[iSeg].sh_addr + offSeg;
924	return rc;
925	}
926
927
928	/** @copydoc RTLDROPS::pfnSegOffsetToRva. */
929	static DECLCALLBACK(int) RTLDRELF_NAME(SegOffsetToRva)(PRTLDRMODINTERNAL pMod, uint32_t iSeg, RTLDRADDR offSeg,
930	PRTLDRADDR pRva)
931	{
932	PRTLDRMODELF pModElf = (PRTLDRMODELF)pMod;
933	if (iSeg >= pModElf->Ehdr.e_shnum - 1U)
934	return VERR_LDR_INVALID_SEG_OFFSET;
935
936	iSeg++; /* skip section 0 */
937	if (offSeg > pModElf->paShdrs[iSeg].sh_size)
938	{
939	const Elf_Shdr *pShdr2 = RTLDRELF_NAME(GetFirstAllocatedSection)(&pModElf->paShdrs[iSeg + 1],
940	pModElf->Ehdr.e_shnum - iSeg - 1);
941	if ( !pShdr2
942	\|\| offSeg > (pShdr2->sh_addr - pModElf->paShdrs[iSeg].sh_addr))
943	return VERR_LDR_INVALID_SEG_OFFSET;
944	}
945
946	if (!(pModElf->paShdrs[iSeg].sh_flags & SHF_ALLOC))
947	return VERR_LDR_INVALID_SEG_OFFSET;
948
949	*pRva = pModElf->paShdrs[iSeg].sh_addr;
950	return VINF_SUCCESS;
951	}
952
953
954	/** @copydoc RTLDROPS::pfnRvaToSegOffset. */
955	static DECLCALLBACK(int) RTLDRELF_NAME(RvaToSegOffset)(PRTLDRMODINTERNAL pMod, RTLDRADDR Rva,
956	uint32_t *piSeg, PRTLDRADDR poffSeg)
957	{
958	PRTLDRMODELF pModElf = (PRTLDRMODELF)pMod;
959
960	Elf_Addr PrevAddr = 0;
961	unsigned cLeft = pModElf->Ehdr.e_shnum - 1;
962	const Elf_Shdr *pShdr = &pModElf->paShdrs[cLeft];
963	while (cLeft-- > 0)
964	{
965	pShdr--;
966	if (pShdr->sh_flags & SHF_ALLOC)
967	{
968	Elf_Addr cbSeg = PrevAddr ? PrevAddr - pShdr->sh_addr : pShdr->sh_size;
969	RTLDRADDR offSeg = Rva - pShdr->sh_addr;
970	if (offSeg <= cbSeg)
971	{
972	*poffSeg = offSeg;
973	*piSeg = cLeft;
974	return VINF_SUCCESS;
975	}
976	PrevAddr = pShdr->sh_addr;
977	}
978	}
979
980	return VERR_LDR_INVALID_RVA;
981	}
982
983
984
985	/**
986	* The ELF module operations.
987	*/
988	static RTLDROPS RTLDRELF_MID(s_rtldrElf,Ops) =
989	{
990	#if ELF_MODE == 32
991	"elf32",
992	#elif ELF_MODE == 64
993	"elf64",
994	#endif
995	RTLDRELF_NAME(Close),
996	NULL, /* Get Symbol */
997	RTLDRELF_NAME(Done),
998	RTLDRELF_NAME(EnumSymbols),
999	/* ext: */
1000	RTLDRELF_NAME(GetImageSize),
1001	RTLDRELF_NAME(GetBits),
1002	RTLDRELF_NAME(Relocate),
1003	RTLDRELF_NAME(GetSymbolEx),
1004	RTLDRELF_NAME(EnumDbgInfo),
1005	RTLDRELF_NAME(EnumSegments),
1006	RTLDRELF_NAME(LinkAddressToSegOffset),
1007	RTLDRELF_NAME(LinkAddressToRva),
1008	RTLDRELF_NAME(SegOffsetToRva),
1009	RTLDRELF_NAME(RvaToSegOffset),
1010	42
1011	};
1012
1013
1014
1015	/**
1016	* Validates the ELF header.
1017	*
1018	* @returns iprt status code.
1019	* @param pEhdr Pointer to the ELF header.
1020	* @param pszLogName The log name.
1021	* @param cbRawImage The size of the raw image.
1022	*/
1023	static int RTLDRELF_NAME(ValidateElfHeader)(const Elf_Ehdr pEhdr, const char pszLogName, uint64_t cbRawImage,
1024	PRTLDRARCH penmArch)
1025	{
1026	Log3(("RTLdrELF: e_ident: %.*Rhxs\n"
1027	"RTLdrELF: e_type: " FMT_ELF_HALF "\n"
1028	"RTLdrELF: e_version: " FMT_ELF_HALF "\n"
1029	"RTLdrELF: e_entry: " FMT_ELF_ADDR "\n"
1030	"RTLdrELF: e_phoff: " FMT_ELF_OFF "\n"
1031	"RTLdrELF: e_shoff: " FMT_ELF_OFF "\n"
1032	"RTLdrELF: e_flags: " FMT_ELF_WORD "\n"
1033	"RTLdrELF: e_ehsize: " FMT_ELF_HALF "\n"
1034	"RTLdrELF: e_phentsize: " FMT_ELF_HALF "\n"
1035	"RTLdrELF: e_phnum: " FMT_ELF_HALF "\n"
1036	"RTLdrELF: e_shentsize: " FMT_ELF_HALF "\n"
1037	"RTLdrELF: e_shnum: " FMT_ELF_HALF "\n"
1038	"RTLdrELF: e_shstrndx: " FMT_ELF_HALF "\n",
1039	RT_ELEMENTS(pEhdr->e_ident), &pEhdr->e_ident[0], pEhdr->e_type, pEhdr->e_version,
1040	pEhdr->e_entry, pEhdr->e_phoff, pEhdr->e_shoff,pEhdr->e_flags, pEhdr->e_ehsize, pEhdr->e_phentsize,
1041	pEhdr->e_phnum, pEhdr->e_shentsize, pEhdr->e_shnum, pEhdr->e_shstrndx));
1042
1043	if ( pEhdr->e_ident[EI_MAG0] != ELFMAG0
1044	\|\| pEhdr->e_ident[EI_MAG1] != ELFMAG1
1045	\|\| pEhdr->e_ident[EI_MAG2] != ELFMAG2
1046	\|\| pEhdr->e_ident[EI_MAG3] != ELFMAG3
1047	)
1048	{
1049	Log(("RTLdrELF: %s: Invalid ELF magic (%.*Rhxs)\n", pszLogName, sizeof(pEhdr->e_ident), pEhdr->e_ident)); NOREF(pszLogName);
1050	return VERR_BAD_EXE_FORMAT;
1051	}
1052	if (pEhdr->e_ident[EI_CLASS] != RTLDRELF_SUFF(ELFCLASS))
1053	{
1054	Log(("RTLdrELF: %s: Invalid ELF class (%.*Rhxs)\n", pszLogName, sizeof(pEhdr->e_ident), pEhdr->e_ident));
1055	return VERR_BAD_EXE_FORMAT;
1056	}
1057	if (pEhdr->e_ident[EI_DATA] != ELFDATA2LSB)
1058	{
1059	Log(("RTLdrELF: %s: ELF endian %x is unsupported\n", pEhdr->e_ident[EI_DATA]));
1060	return VERR_LDRELF_ODD_ENDIAN;
1061	}
1062	if (pEhdr->e_version != EV_CURRENT)
1063	{
1064	Log(("RTLdrELF: %s: ELF version %x is unsupported\n", pEhdr->e_version));
1065	return VERR_LDRELF_VERSION;
1066	}
1067
1068	if (sizeof(Elf_Ehdr) != pEhdr->e_ehsize)
1069	{
1070	Log(("RTLdrELF: %s: Elf header e_ehsize is %d expected %d!\n",
1071	pszLogName, pEhdr->e_ehsize, sizeof(Elf_Ehdr)));
1072	return VERR_BAD_EXE_FORMAT;
1073	}
1074	if ( sizeof(Elf_Phdr) != pEhdr->e_phentsize
1075	&& ( pEhdr->e_phnum != 0
1076	\|\| pEhdr->e_type == ET_DYN))
1077	{
1078	Log(("RTLdrELF: %s: Elf header e_phentsize is %d expected %d!\n",
1079	pszLogName, pEhdr->e_phentsize, sizeof(Elf_Phdr)));
1080	return VERR_BAD_EXE_FORMAT;
1081	}
1082	if (sizeof(Elf_Shdr) != pEhdr->e_shentsize)
1083	{
1084	Log(("RTLdrELF: %s: Elf header e_shentsize is %d expected %d!\n",
1085	pszLogName, pEhdr->e_shentsize, sizeof(Elf_Shdr)));
1086	return VERR_BAD_EXE_FORMAT;
1087	}
1088
1089	switch (pEhdr->e_type)
1090	{
1091	case ET_REL:
1092	case ET_EXEC:
1093	case ET_DYN:
1094	break;
1095	default:
1096	Log(("RTLdrELF: %s: image type %#x is not supported!\n", pszLogName, pEhdr->e_type));
1097	return VERR_BAD_EXE_FORMAT;
1098	}
1099
1100	switch (pEhdr->e_machine)
1101	{
1102	#if ELF_MODE == 32
1103	case EM_386:
1104	case EM_486:
1105	*penmArch = RTLDRARCH_X86_32;
1106	break;
1107	#elif ELF_MODE == 64
1108	case EM_X86_64:
1109	*penmArch = RTLDRARCH_AMD64;
1110	break;
1111	#endif
1112	default:
1113	Log(("RTLdrELF: %s: machine type %u is not supported!\n", pEhdr->e_machine));
1114	return VERR_LDRELF_MACHINE;
1115	}
1116
1117	if ( pEhdr->e_phoff < pEhdr->e_ehsize
1118	&& !(pEhdr->e_phoff && pEhdr->e_phnum)
1119	&& pEhdr->e_phnum)
1120	{
1121	Log(("RTLdrELF: %s: The program headers overlap with the ELF header! e_phoff=" FMT_ELF_OFF "\n",
1122	pszLogName, pEhdr->e_phoff));
1123	return VERR_BAD_EXE_FORMAT;
1124	}
1125	if ( pEhdr->e_phoff + pEhdr->e_phnum * pEhdr->e_phentsize > cbRawImage
1126	\|\| pEhdr->e_phoff + pEhdr->e_phnum * pEhdr->e_phentsize < pEhdr->e_phoff)
1127	{
1128	Log(("RTLdrELF: %s: The program headers extends beyond the file! e_phoff=" FMT_ELF_OFF " e_phnum=" FMT_ELF_HALF "\n",
1129	pszLogName, pEhdr->e_phoff, pEhdr->e_phnum));
1130	return VERR_BAD_EXE_FORMAT;
1131	}
1132
1133
1134	if ( pEhdr->e_shoff < pEhdr->e_ehsize
1135	&& !(pEhdr->e_shoff && pEhdr->e_shnum))
1136	{
1137	Log(("RTLdrELF: %s: The section headers overlap with the ELF header! e_shoff=" FMT_ELF_OFF "\n",
1138	pszLogName, pEhdr->e_shoff));
1139	return VERR_BAD_EXE_FORMAT;
1140	}
1141	if ( pEhdr->e_shoff + pEhdr->e_shnum * pEhdr->e_shentsize > cbRawImage
1142	\|\| pEhdr->e_shoff + pEhdr->e_shnum * pEhdr->e_shentsize < pEhdr->e_shoff)
1143	{
1144	Log(("RTLdrELF: %s: The section headers extends beyond the file! e_shoff=" FMT_ELF_OFF " e_shnum=" FMT_ELF_HALF "\n",
1145	pszLogName, pEhdr->e_shoff, pEhdr->e_shnum));
1146	return VERR_BAD_EXE_FORMAT;
1147	}
1148
1149	return VINF_SUCCESS;
1150	}
1151
1152	/**
1153	* Gets the section header name.
1154	*
1155	* @returns pszName.
1156	* @param pReader The loader reader instance.
1157	* @param pEhdr The elf header.
1158	* @param offName The offset of the section header name.
1159	* @param pszName Where to store the name.
1160	* @param cbName The size of the buffer pointed to by pszName.
1161	*/
1162	const char RTLDRELF_NAME(GetSHdrName)(PRTLDRMODELF pModElf, Elf_Word offName, char pszName, size_t cbName)
1163	{
1164	RTFOFF off = pModElf->paShdrs[pModElf->Ehdr.e_shstrndx].sh_offset + offName;
1165	int rc = pModElf->pReader->pfnRead(pModElf->pReader, pszName, cbName - 1, off);
1166	if (RT_FAILURE(rc))
1167	{
1168	/* read by for byte. */
1169	for (unsigned i = 0; i < cbName; i++, off++)
1170	{
1171	rc = pModElf->pReader->pfnRead(pModElf->pReader, pszName + i, 1, off);
1172	if (RT_FAILURE(rc))
1173	{
1174	pszName[i] = '\0';
1175	break;
1176	}
1177	}
1178	}
1179
1180	pszName[cbName - 1] = '\0';
1181	return pszName;
1182	}
1183
1184
1185	/**
1186	* Validates a section header.
1187	*
1188	* @returns iprt status code.
1189	* @param pModElf Pointer to the module structure.
1190	* @param iShdr The index of section header which should be validated.
1191	* The section headers are found in the pModElf->paShdrs array.
1192	* @param pszLogName The log name.
1193	* @param cbRawImage The size of the raw image.
1194	*/
1195	static int RTLDRELF_NAME(ValidateSectionHeader)(PRTLDRMODELF pModElf, unsigned iShdr, const char *pszLogName, RTFOFF cbRawImage)
1196	{
1197	const Elf_Shdr *pShdr = &pModElf->paShdrs[iShdr];
1198	char szSectionName[80]; NOREF(szSectionName);
1199	Log3(("RTLdrELF: Section Header #%d:\n"
1200	"RTLdrELF: sh_name: " FMT_ELF_WORD " - %s\n"
1201	"RTLdrELF: sh_type: " FMT_ELF_WORD " (%s)\n"
1202	"RTLdrELF: sh_flags: " FMT_ELF_XWORD "\n"
1203	"RTLdrELF: sh_addr: " FMT_ELF_ADDR "\n"
1204	"RTLdrELF: sh_offset: " FMT_ELF_OFF "\n"
1205	"RTLdrELF: sh_size: " FMT_ELF_XWORD "\n"
1206	"RTLdrELF: sh_link: " FMT_ELF_WORD "\n"
1207	"RTLdrELF: sh_info: " FMT_ELF_WORD "\n"
1208	"RTLdrELF: sh_addralign: " FMT_ELF_XWORD "\n"
1209	"RTLdrELF: sh_entsize: " FMT_ELF_XWORD "\n",
1210	iShdr,
1211	pShdr->sh_name, RTLDRELF_NAME(GetSHdrName)(pModElf, pShdr->sh_name, szSectionName, sizeof(szSectionName)),
1212	pShdr->sh_type, rtldrElfGetShdrType(pShdr->sh_type), pShdr->sh_flags, pShdr->sh_addr,
1213	pShdr->sh_offset, pShdr->sh_size, pShdr->sh_link, pShdr->sh_info, pShdr->sh_addralign,
1214	pShdr->sh_entsize));
1215
1216	if (iShdr == 0)
1217	{
1218	if ( pShdr->sh_name != 0
1219	\|\| pShdr->sh_type != SHT_NULL
1220	\|\| pShdr->sh_flags != 0
1221	\|\| pShdr->sh_addr != 0
1222	\|\| pShdr->sh_size != 0
1223	\|\| pShdr->sh_offset != 0
1224	\|\| pShdr->sh_link != SHN_UNDEF
1225	\|\| pShdr->sh_addralign != 0
1226	\|\| pShdr->sh_entsize != 0 )
1227	{
1228	Log(("RTLdrELF: %s: Bad #0 section: %.Rhxs\n", pszLogName, sizeof(pShdr), pShdr ));
1229	return VERR_BAD_EXE_FORMAT;
1230	}
1231	return VINF_SUCCESS;
1232	}
1233
1234	if (pShdr->sh_link >= pModElf->Ehdr.e_shnum)
1235	{
1236	Log(("RTLdrELF: %s: Shdr #%d: sh_link (%d) is beyond the end of the section table (%d)!\n",
1237	pszLogName, iShdr, pShdr->sh_link, pModElf->Ehdr.e_shnum)); NOREF(pszLogName);
1238	return VERR_BAD_EXE_FORMAT;
1239	}
1240
1241	switch (pShdr->sh_type)
1242	{
1243	/** @todo find specs and check up which sh_info fields indicates section table entries */
1244	case 12301230:
1245	if (pShdr->sh_info >= pModElf->Ehdr.e_shnum)
1246	{
1247	Log(("RTLdrELF: %s: Shdr #%d: sh_info (%d) is beyond the end of the section table (%d)!\n",
1248	pszLogName, iShdr, pShdr->sh_link, pModElf->Ehdr.e_shnum));
1249	return VERR_BAD_EXE_FORMAT;
1250	}
1251	break;
1252
1253	case SHT_NULL:
1254	break;
1255	case SHT_PROGBITS:
1256	case SHT_SYMTAB:
1257	case SHT_STRTAB:
1258	case SHT_RELA:
1259	case SHT_HASH:
1260	case SHT_DYNAMIC:
1261	case SHT_NOTE:
1262	case SHT_NOBITS:
1263	case SHT_REL:
1264	case SHT_SHLIB:
1265	case SHT_DYNSYM:
1266	/*
1267	* For these types sh_info doesn't have any special meaning, or anything which
1268	* we need/can validate now.
1269	*/
1270	break;
1271
1272
1273	default:
1274	Log(("RTLdrELF: %s: Warning, unknown type %d!\n", pszLogName, pShdr->sh_type));
1275	break;
1276	}
1277
1278	if ( pShdr->sh_type != SHT_NOBITS
1279	&& pShdr->sh_size)
1280	{
1281	RTFOFF offEnd = pShdr->sh_offset + pShdr->sh_size;
1282	if ( offEnd > cbRawImage
1283	\|\| offEnd < (RTFOFF)pShdr->sh_offset)
1284	{
1285	Log(("RTLdrELF: %s: Shdr #%d: sh_offset (" FMT_ELF_OFF ") + sh_size (" FMT_ELF_XWORD " = %RTfoff) is beyond the end of the file (%RTfoff)!\n",
1286	pszLogName, iShdr, pShdr->sh_offset, pShdr->sh_size, offEnd, cbRawImage));
1287	return VERR_BAD_EXE_FORMAT;
1288	}
1289	if (pShdr->sh_offset < sizeof(Elf_Ehdr))
1290	{
1291	Log(("RTLdrELF: %s: Shdr #%d: sh_offset (" FMT_ELF_OFF ") + sh_size (" FMT_ELF_XWORD ") is starting in the ELF header!\n",
1292	pszLogName, iShdr, pShdr->sh_offset, pShdr->sh_size, cbRawImage));
1293	return VERR_BAD_EXE_FORMAT;
1294	}
1295	}
1296
1297	return VINF_SUCCESS;
1298	}
1299
1300
1301
1302	/**
1303	* Opens an ELF image, fixed bitness.
1304	*
1305	* @returns iprt status code.
1306	* @param pReader The loader reader instance which will provide the raw image bits.
1307	* @param fFlags Reserved, MBZ.
1308	* @param enmArch Architecture specifier.
1309	* @param phLdrMod Where to store the handle.
1310	*/
1311	static int RTLDRELF_NAME(Open)(PRTLDRREADER pReader, uint32_t fFlags, RTLDRARCH enmArch, PRTLDRMOD phLdrMod)
1312	{
1313	const char *pszLogName = pReader->pfnLogName(pReader);
1314	RTFOFF cbRawImage = pReader->pfnSize(pReader);
1315	AssertReturn(!fFlags, VERR_INVALID_PARAMETER);
1316
1317	/*
1318	* Create the loader module instance.
1319	*/
1320	PRTLDRMODELF pModElf = (PRTLDRMODELF)RTMemAllocZ(sizeof(*pModElf));
1321	if (!pModElf)
1322	return VERR_NO_MEMORY;
1323
1324	pModElf->Core.u32Magic = RTLDRMOD_MAGIC;
1325	pModElf->Core.eState = LDR_STATE_INVALID;
1326	pModElf->pReader = pReader;
1327	//pModElf->pvBits = NULL;
1328	//pModElf->Ehdr = {0};
1329	//pModElf->paShdrs = NULL;
1330	//pModElf->paSyms = NULL;
1331	pModElf->iSymSh = ~0U;
1332	pModElf->cSyms = 0;
1333	pModElf->iStrSh = ~0U;
1334	pModElf->cbStr = 0;
1335	pModElf->cbImage = 0;
1336	//pModElf->pStr = NULL;
1337
1338	/*
1339	* Read and validate the ELF header and match up the CPU architecture.
1340	*/
1341	int rc = pReader->pfnRead(pReader, &pModElf->Ehdr, sizeof(pModElf->Ehdr), 0);
1342	if (RT_SUCCESS(rc))
1343	{
1344	RTLDRARCH enmArchImage = RTLDRARCH_INVALID; /* shut up gcc */
1345	rc = RTLDRELF_NAME(ValidateElfHeader)(&pModElf->Ehdr, pszLogName, cbRawImage, &enmArchImage);
1346	if (RT_SUCCESS(rc))
1347	{
1348	if ( enmArch != RTLDRARCH_WHATEVER
1349	&& enmArch != enmArchImage)
1350	rc = VERR_LDR_ARCH_MISMATCH;
1351	}
1352	}
1353	if (RT_SUCCESS(rc))
1354	{
1355	/*
1356	* Read the section headers, keeping a prestine copy for the module
1357	* introspection methods.
1358	*/
1359	size_t const cbShdrs = pModElf->Ehdr.e_shnum * sizeof(Elf_Shdr);
1360	Elf_Shdr paShdrs = (Elf_Shdr )RTMemAlloc(cbShdrs * 2);
1361	if (paShdrs)
1362	{
1363	pModElf->paShdrs = paShdrs;
1364	rc = pReader->pfnRead(pReader, paShdrs, cbShdrs, pModElf->Ehdr.e_shoff);
1365	if (RT_SUCCESS(rc))
1366	{
1367	memcpy(&paShdrs[pModElf->Ehdr.e_shnum], paShdrs, cbShdrs);
1368	pModElf->paOrgShdrs = &paShdrs[pModElf->Ehdr.e_shnum];
1369
1370	/*
1371	* Validate the section headers, allocate memory for the sections (determine the image size),
1372	* and find relevant sections.
1373	*/
1374	for (unsigned i = 0; i < pModElf->Ehdr.e_shnum; i++)
1375	{
1376	rc = RTLDRELF_NAME(ValidateSectionHeader)(pModElf, i, pszLogName, cbRawImage);
1377	if (RT_FAILURE(rc))
1378	break;
1379
1380	/* Allocate memory addresses for the section. */
1381	if (paShdrs[i].sh_flags & SHF_ALLOC)
1382	{
1383	paShdrs[i].sh_addr = paShdrs[i].sh_addralign
1384	? RT_ALIGN_T(pModElf->cbImage, paShdrs[i].sh_addralign, Elf_Addr)
1385	: (Elf_Addr)pModElf->cbImage;
1386	pModElf->cbImage = (size_t)paShdrs[i].sh_addr + (size_t)paShdrs[i].sh_size;
1387	AssertMsgReturn(pModElf->cbImage == paShdrs[i].sh_addr + paShdrs[i].sh_size,
1388	(FMT_ELF_ADDR "\n", paShdrs[i].sh_addr + paShdrs[i].sh_size),
1389	VERR_IMAGE_TOO_BIG);
1390	Log2(("RTLdrElf: %s: Assigned " FMT_ELF_ADDR " to section #%d\n", pszLogName, paShdrs[i].sh_addr, i));
1391	}
1392
1393	/* We're looking for symbol tables. */
1394	if (paShdrs[i].sh_type == SHT_SYMTAB)
1395	{
1396	if (pModElf->iSymSh != ~0U)
1397	{
1398	Log(("RTLdrElf: %s: Multiple symbol tabs! iSymSh=%d i=%d\n", pszLogName, pModElf->iSymSh, i));
1399	rc = VERR_LDRELF_MULTIPLE_SYMTABS;
1400	break;
1401	}
1402	pModElf->iSymSh = i;
1403	pModElf->cSyms = (unsigned)(paShdrs[i].sh_size / sizeof(Elf_Sym));
1404	AssertReturn(pModElf->cSyms == paShdrs[i].sh_size / sizeof(Elf_Sym), VERR_IMAGE_TOO_BIG);
1405	pModElf->iStrSh = paShdrs[i].sh_link;
1406	pModElf->cbStr = (unsigned)paShdrs[pModElf->iStrSh].sh_size;
1407	AssertReturn(pModElf->cbStr == paShdrs[pModElf->iStrSh].sh_size, VERR_IMAGE_TOO_BIG);
1408	}
1409	else if (paShdrs[i].sh_type == SHT_STRTAB)
1410	{
1411	pModElf->iStrSh = i;
1412	pModElf->cbStr = (unsigned)paShdrs[i].sh_size;
1413	AssertReturn(pModElf->cbStr == paShdrs[i].sh_size, VERR_IMAGE_TOO_BIG);
1414	}
1415
1416	} /* for each section header */
1417
1418	Log2(("RTLdrElf: iSymSh=%u cSyms=%u iStrSh=%u cbStr=%u rc=%Rrc cbImage=%#zx\n",
1419	pModElf->iSymSh, pModElf->cSyms, pModElf->iStrSh, pModElf->cbStr, rc, pModElf->cbImage));
1420	#if 0
1421	/*
1422	* Are the section headers fine?
1423	* We require there to be symbol & string tables (at least for the time being).
1424	*/
1425	if ( pModElf->iSymSh == ~0U
1426	\|\| pModElf->iStrSh == ~0U)
1427	rc = VERR_LDRELF_NO_SYMBOL_OR_NO_STRING_TABS;
1428	#endif
1429	if (RT_SUCCESS(rc))
1430	{
1431	pModElf->Core.pOps = &RTLDRELF_MID(s_rtldrElf,Ops);
1432	pModElf->Core.eState = LDR_STATE_OPENED;
1433	*phLdrMod = &pModElf->Core;
1434
1435	LogFlow(("%s: %s: returns VINF_SUCCESS phLdrMod=%p\n", __FUNCTION__, pszLogName, phLdrMod));
1436	return VINF_SUCCESS;
1437	}
1438	}
1439
1440	RTMemFree(paShdrs);
1441	}
1442	else
1443	rc = VERR_NO_MEMORY;
1444	}
1445
1446	RTMemFree(pModElf);
1447	LogFlow(("%s: returns %Rrc\n", __FUNCTION__, rc));
1448	return rc;
1449	}
1450
1451
1452
1453
1454	/*******************************************************************************
1455	* Cleanup Constants And Macros *
1456	*******************************************************************************/
1457	#undef RTLDRELF_NAME
1458	#undef RTLDRELF_SUFF
1459	#undef RTLDRELF_MID
1460
1461	#undef FMT_ELF_ADDR
1462	#undef FMT_ELF_HALF
1463	#undef FMT_ELF_SHALF
1464	#undef FMT_ELF_OFF
1465	#undef FMT_ELF_SIZE
1466	#undef FMT_ELF_SWORD
1467	#undef FMT_ELF_WORD
1468	#undef FMT_ELF_XWORD
1469	#undef FMT_ELF_SXWORD
1470
1471	#undef Elf_Ehdr
1472	#undef Elf_Phdr
1473	#undef Elf_Shdr
1474	#undef Elf_Sym
1475	#undef Elf_Rel
1476	#undef Elf_Rela
1477	#undef Elf_Reloc
1478	#undef Elf_Nhdr
1479	#undef Elf_Dyn
1480
1481	#undef Elf_Addr
1482	#undef Elf_Half
1483	#undef Elf_Off
1484	#undef Elf_Size
1485	#undef Elf_Sword
1486	#undef Elf_Word
1487
1488	#undef RTLDRMODELF
1489	#undef PRTLDRMODELF
1490
1491	#undef ELF_R_SYM
1492	#undef ELF_R_TYPE
1493	#undef ELF_R_INFO
1494
1495	#undef ELF_ST_BIND
1496

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source: vbox/trunk/src/VBox/Runtime/common/ldr/ldrELFRelocatable.cpp.h@ 45968

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