5 #include <libelfu/libelfu.h>
8 static void parseSymtab(ElfuElf *me, ElfuScn *ms, ElfuScn**origScnArr)
17 /* Parse symbols from their elfclass-specific format */
18 if (me->elfclass == ELFCLASS32) {
19 for (i = 1; (i + 1) * sizeof(Elf32_Sym) <= ms->shdr.sh_size; i++) {
20 Elf32_Sym *cursym = ((Elf32_Sym*)ms->databuf) + i;
21 ElfuSym *newsym = malloc(sizeof(*sym));
24 newsym->name = cursym->st_name;
25 newsym->value = cursym->st_value;
26 newsym->size = cursym->st_size;
27 newsym->bind = ELF32_ST_BIND(cursym->st_info);
28 newsym->type = ELF32_ST_TYPE(cursym->st_info);
29 newsym->other = cursym->st_other;
30 newsym->shndx = cursym->st_shndx;
32 CIRCLEQ_INSERT_TAIL(&ms->symtab.syms, newsym, elem);
34 } else if (me->elfclass == ELFCLASS64) {
35 for (i = 1; (i + 1) * sizeof(Elf64_Sym) <= ms->shdr.sh_size; i++) {
36 Elf64_Sym *cursym = ((Elf64_Sym*)ms->databuf) + i;
37 ElfuSym *newsym = malloc(sizeof(*sym));
40 newsym->name = cursym->st_name;
41 newsym->value = cursym->st_value;
42 newsym->size = cursym->st_size;
43 newsym->bind = ELF64_ST_BIND(cursym->st_info);
44 newsym->type = ELF64_ST_TYPE(cursym->st_info);
45 newsym->other = cursym->st_other;
46 newsym->shndx = cursym->st_shndx;
48 CIRCLEQ_INSERT_TAIL(&ms->symtab.syms, newsym, elem);
51 /* Unknown elfclass */
55 /* For each section, find the section it points to if any. */
56 CIRCLEQ_FOREACH(sym, &ms->symtab.syms, elem) {
64 sym->scnptr = origScnArr[sym->shndx - 1];
71 static void parseReltab(ElfuElf *me, ElfuScn *ms)
78 if (me->elfclass == ELFCLASS32) {
79 for (i = 0; (i + 1) * sizeof(Elf32_Rel) <= ms->shdr.sh_size; i++) {
80 Elf32_Rel *currel = &(((Elf32_Rel*)ms->databuf)[i]);
83 rel = malloc(sizeof(*rel));
86 rel->offset = currel->r_offset;
87 rel->sym = ELF32_R_SYM(currel->r_info);
88 rel->type = ELF32_R_TYPE(currel->r_info);
92 CIRCLEQ_INSERT_TAIL(&ms->reltab.rels, rel, elem);
94 } else if (me->elfclass == ELFCLASS64) {
95 for (i = 0; (i + 1) * sizeof(Elf64_Rel) <= ms->shdr.sh_size; i++) {
96 Elf64_Rel *currel = &(((Elf64_Rel*)ms->databuf)[i]);
99 rel = malloc(sizeof(*rel));
102 rel->offset = currel->r_offset;
103 rel->sym = ELF64_R_SYM(currel->r_info);
104 rel->type = ELF64_R_TYPE(currel->r_info);
108 CIRCLEQ_INSERT_TAIL(&ms->reltab.rels, rel, elem);
111 /* Unknown elfclass */
117 static void parseRelatab(ElfuElf *me, ElfuScn *ms)
124 if (me->elfclass == ELFCLASS32) {
125 for (i = 0; (i + 1) * sizeof(Elf32_Rela) <= ms->shdr.sh_size; i++) {
126 Elf32_Rela *currel = &(((Elf32_Rela*)ms->databuf)[i]);
129 rel = malloc(sizeof(*rel));
132 rel->offset = currel->r_offset;
133 rel->sym = ELF32_R_SYM(currel->r_info);
134 rel->type = ELF32_R_TYPE(currel->r_info);
136 rel->addend = currel->r_addend;
138 CIRCLEQ_INSERT_TAIL(&ms->reltab.rels, rel, elem);
140 } else if (me->elfclass == ELFCLASS64) {
141 for (i = 0; (i + 1) * sizeof(Elf64_Rela) <= ms->shdr.sh_size; i++) {
142 Elf64_Rela *currel = &(((Elf64_Rela*)ms->databuf)[i]);
145 rel = malloc(sizeof(*rel));
148 rel->offset = currel->r_offset;
149 rel->sym = ELF64_R_SYM(currel->r_info);
150 rel->type = ELF64_R_TYPE(currel->r_info);
152 rel->addend = currel->r_addend;
154 CIRCLEQ_INSERT_TAIL(&ms->reltab.rels, rel, elem);
157 /* Unknown elfclass */
163 static int cmpScnOffs(const void *ms1, const void *ms2)
165 ElfuScn *s1 = *(ElfuScn**)ms1;
166 ElfuScn *s2 = *(ElfuScn**)ms2;
171 s1 = *(ElfuScn**)ms1;
172 s2 = *(ElfuScn**)ms2;
178 if (s1->shdr.sh_offset < s2->shdr.sh_offset) {
180 } else if (s1->shdr.sh_offset == s2->shdr.sh_offset) {
182 } else /* if (s1->shdr.sh_offset > s2->shdr.sh_offset) */ {
189 static ElfuPhdr* parentPhdr(ElfuElf *me, ElfuScn *ms)
196 CIRCLEQ_FOREACH(mp, &me->phdrList, elem) {
197 if (mp->phdr.p_type != PT_LOAD) {
201 if (PHDR_CONTAINS_SCN_IN_MEMORY(&mp->phdr, &ms->shdr)) {
210 static ElfuPhdr* modelFromPhdr(GElf_Phdr *phdr)
216 mp = elfu_mPhdrAlloc();
227 static ElfuScn* modelFromSection(Elf_Scn *scn)
233 ms = elfu_mScnAlloc();
239 assert(gelf_getshdr(scn, &ms->shdr) == &ms->shdr);
241 /* Copy each data part in source segment */
242 if (SCNFILESIZE(&ms->shdr) > 0) {
245 ms->databuf = malloc(ms->shdr.sh_size);
247 ELFU_WARN("modelFromSection: malloc() failed for data buffer (%x bytes).\n", (unsigned)ms->shdr.sh_size);
251 /* A non-empty section should contain at least one data block. */
252 data = elf_rawdata(scn, NULL);
255 /* elf_rawdata() always returns ELF_T_BYTE */
256 assert(data->d_type == ELF_T_BYTE);
259 if (data->d_off + data->d_size > ms->shdr.sh_size) {
260 ELFU_WARN("modelFromSection: libelf delivered a bogus data blob. Skipping\n");
262 memcpy((char*)ms->databuf + data->d_off, data->d_buf, data->d_size);
265 data = elf_rawdata(scn, data);
281 ElfuElf* elfu_mFromElf(Elf *e)
285 size_t i, numPhdr, numShdr;
286 ElfuScn **secArray = NULL;
289 if (elfu_eCheck(e)) {
293 me = elfu_mElfAlloc();
298 me->elfclass = gelf_getclass(e);
299 assert(me->elfclass != ELFCLASSNONE);
300 assert(gelf_getehdr(e, &me->ehdr) == &me->ehdr);
303 /* Get the section string table index */
304 if (elf_getshdrstrndx(e, &shstrndx) != 0) {
310 assert(!elf_getphdrnum(e, &numPhdr));
311 for (i = 0; i < numPhdr; i++) {
315 assert(gelf_getphdr(e, i, &phdr) == &phdr);
317 mp = modelFromPhdr(&phdr);
322 CIRCLEQ_INSERT_TAIL(&me->phdrList, mp, elem);
328 /* Find PHDR -> PHDR dependencies (needs sorted sections) */
329 CIRCLEQ_FOREACH(mp, &me->phdrList, elem) {
332 if (mp->phdr.p_type != PT_LOAD) {
336 CIRCLEQ_FOREACH(mp2, &me->phdrList, elem) {
341 if (mp->phdr.p_vaddr <= mp2->phdr.p_vaddr
342 && OFFS_END(mp2->phdr.p_vaddr, mp2->phdr.p_memsz) <= OFFS_END(mp->phdr.p_vaddr, mp->phdr.p_memsz)) {
343 /* Remove from the main list so only LOADs remain there */
344 CIRCLEQ_REMOVE(&me->phdrList, mp2, elem);
345 CIRCLEQ_INSERT_TAIL(&mp->childPhdrList, mp2, elemChildPhdr);
353 assert(!elf_getshdrnum(e, &numShdr));
355 secArray = malloc((numShdr - 1) * sizeof(*secArray));
357 ELFU_WARN("elfu_mFromElf: malloc() failed for secArray.\n");
361 for (i = 1; i < numShdr; i++) {
365 scn = elf_getscn(e, i);
368 ms = modelFromSection(scn);
381 /* Find sh_link and sh_info dependencies (needs sections in original order) */
382 for (i = 0; i < numShdr - 1; i++) {
383 ElfuScn *ms = secArray[i];
385 switch (ms->shdr.sh_type) {
388 if (ms->shdr.sh_info > 0) {
389 ms->infoptr = secArray[ms->shdr.sh_info - 1];
397 case SHT_GNU_verneed:
398 if (ms->shdr.sh_link > 0) {
399 ms->linkptr = secArray[ms->shdr.sh_link - 1];
405 /* Parse symtabs (needs sections in original order) */
406 for (i = 0; i < numShdr - 1; i++) {
407 ElfuScn *ms = secArray[i];
409 switch (ms->shdr.sh_type) {
413 parseSymtab(me, ms, secArray);
419 /* Parse relocations (needs sections in original order) */
420 for (i = 0; i < numShdr - 1; i++) {
421 ElfuScn *ms = secArray[i];
423 switch (ms->shdr.sh_type) {
428 parseRelatab(me, ms);
434 /* Sort sections by file offset */
435 qsort(secArray, numShdr - 1, sizeof(*secArray), cmpScnOffs);
438 /* Find PHDR -> Section dependencies (needs sorted sections) */
439 for (i = 0; i < numShdr - 1; i++) {
440 ElfuScn *ms = secArray[i];
442 ElfuPhdr *parent = parentPhdr(me, ms);
445 GElf_Off shaddr = parent->phdr.p_vaddr +
446 (ms->shdr.sh_offset - parent->phdr.p_offset);
448 if (ms->shdr.sh_addr == 0) {
449 ms->shdr.sh_addr = shaddr;
451 assert(ms->shdr.sh_addr == shaddr);
454 CIRCLEQ_INSERT_TAIL(&parent->childScnList, ms, elemChildScn);
456 CIRCLEQ_INSERT_TAIL(&me->orphanScnList, ms, elemChildScn);
470 elfu_mElfDestroy(me);
473 ELFU_WARN("elfu_mFromElf: Failed to load file.\n");