5 #include <libelf/libelf.h>
6 #include <libelf/gelf.h>
7 #include <libelfu/libelfu.h>
10 static int cmpScnOffs(const void *ms1, const void *ms2)
15 ElfuScn *s1 = *(ElfuScn**)ms1;
16 ElfuScn *s2 = *(ElfuScn**)ms2;
22 if (s1->shdr.sh_offset < s2->shdr.sh_offset) {
24 } else if (s1->shdr.sh_offset == s2->shdr.sh_offset) {
26 } else /* if (s1->shdr.sh_offset > s2->shdr.sh_offset) */ {
33 static ElfuPhdr* parentPhdr(ElfuElf *me, ElfuScn *ms)
40 CIRCLEQ_FOREACH(mp, &me->phdrList, elem) {
41 if (mp->phdr.p_type != PT_LOAD) {
45 if (ms->shdr.sh_addr >= mp->phdr.p_vaddr
46 && OFFS_END(ms->shdr.sh_addr, ms->shdr.sh_size) <= OFFS_END(mp->phdr.p_vaddr, mp->phdr.p_memsz)) {
48 } else if (ms->shdr.sh_offset >= mp->phdr.p_offset
49 && OFFS_END(ms->shdr.sh_offset, SCNFILESIZE(&ms->shdr)) <= OFFS_END(mp->phdr.p_offset, mp->phdr.p_filesz)
50 && OFFS_END(ms->shdr.sh_offset, ms->shdr.sh_size) <= OFFS_END(mp->phdr.p_offset, mp->phdr.p_memsz)) {
59 static ElfuPhdr* modelFromPhdr(GElf_Phdr *phdr)
65 mp = malloc(sizeof(ElfuPhdr));
67 ELFU_WARN("modelFromPhdr: malloc() failed for ElfuPhdr.\n");
73 CIRCLEQ_INIT(&mp->childScnList);
74 CIRCLEQ_INIT(&mp->childPhdrList);
80 static ElfuScn* modelFromSection(Elf_Scn *scn)
86 ms = malloc(sizeof(ElfuScn));
88 ELFU_WARN("modelFromSection: malloc() failed for ElfuScn.\n");
93 assert(gelf_getshdr(scn, &ms->shdr) == &ms->shdr);
96 /* Copy each data part in source segment */
98 ms->data.d_buf = NULL;
100 ms->data.d_type = ELF_T_BYTE;
101 ms->data.d_size = ms->shdr.sh_size;
102 ms->data.d_version = elf_version(EV_NONE);
103 if (ms->shdr.sh_type != SHT_NOBITS
104 && ms->shdr.sh_size > 0) {
107 ms->data.d_buf = malloc(ms->shdr.sh_size);
108 if (!ms->data.d_buf) {
109 ELFU_WARN("modelFromSection: malloc() failed for data buffer (%jx bytes).\n", ms->shdr.sh_size);
113 /* A non-empty section should contain at least one data block. */
114 data = elf_rawdata(scn, NULL);
117 ms->data.d_align = data->d_align;
118 ms->data.d_type = data->d_type;
119 ms->data.d_version = data->d_version;
122 if (data->d_off + data->d_size > ms->shdr.sh_size) {
123 ELFU_WARN("modelFromSection: libelf delivered a bogus data blob. Skipping\n");
125 memcpy(ms->data.d_buf + data->d_off, data->d_buf, data->d_size);
128 data = elf_rawdata(scn, data);
148 ElfuElf* elfu_mFromElf(Elf *e)
152 size_t i, numPhdr, numShdr;
153 ElfuScn **secArray = NULL;
156 if (elfu_eCheck(e)) {
160 me = malloc(sizeof(ElfuElf));
162 ELFU_WARN("elfu_mFromElf: malloc() failed for ElfuElf.\n");
168 CIRCLEQ_INIT(&me->scnList);
169 CIRCLEQ_INIT(&me->phdrList);
172 me->elfclass = gelf_getclass(e);
173 assert(me->elfclass != ELFCLASSNONE);
174 assert(gelf_getehdr(e, &me->ehdr) == &me->ehdr);
177 /* Get the section string table index */
178 if (elf_getshdrstrndx(e, &shstrndx) != 0) {
184 assert(!elf_getphdrnum(e, &numPhdr));
185 for (i = 0; i < numPhdr; i++) {
189 assert(gelf_getphdr(e, i, &phdr) == &phdr);
191 mp = modelFromPhdr(&phdr);
196 CIRCLEQ_INSERT_TAIL(&me->phdrList, mp, elem);
202 /* Find PHDR -> PHDR dependencies (needs sorted sections) */
203 CIRCLEQ_FOREACH(mp, &me->phdrList, elem) {
206 if (mp->phdr.p_type != PT_LOAD) {
210 CIRCLEQ_FOREACH(mp2, &me->phdrList, elem) {
215 if (mp->phdr.p_vaddr <= mp2->phdr.p_vaddr
216 && OFFS_END(mp2->phdr.p_vaddr, mp2->phdr.p_memsz) <= OFFS_END(mp->phdr.p_vaddr, mp->phdr.p_memsz)) {
217 CIRCLEQ_INSERT_TAIL(&mp->childPhdrList, mp2, elemChildPhdr);
225 assert(!elf_getshdrnum(e, &numShdr));
227 secArray = malloc((numShdr - 1) * sizeof(*secArray));
229 ELFU_WARN("elfu_mFromElf: malloc() failed for secArray.\n");
233 for (i = 1; i < numShdr; i++) {
237 scn = elf_getscn(e, i);
240 ms = modelFromSection(scn);
253 /* Find sh_link dependencies */
254 for (i = 0; i < numShdr - 1; i++) {
255 ElfuScn *ms = secArray[i];
257 switch (ms->shdr.sh_type) {
260 if (ms->shdr.sh_info > 0) {
261 ms->infoptr = secArray[ms->shdr.sh_info - 1];
269 case SHT_GNU_verneed:
270 if (ms->shdr.sh_link > 0) {
271 ms->linkptr = secArray[ms->shdr.sh_link - 1];
277 /* Sort sections by file offset */
278 qsort(secArray, numShdr - 1, sizeof(*secArray), cmpScnOffs);
281 /* Find PHDR -> Section dependencies (needs sorted sections) */
282 for (i = 0; i < numShdr - 1; i++) {
283 ElfuScn *ms = secArray[i];
285 ElfuPhdr *parent = parentPhdr(me, ms);
288 CIRCLEQ_INSERT_TAIL(&parent->childScnList, ms, elemChildScn);
293 /* Put sections into list of all sections */
294 for (i = 0; i < numShdr - 1; i++) {
295 CIRCLEQ_INSERT_TAIL(&me->scnList, secArray[i], elem);
308 // TODO: Free data structures
311 ELFU_WARN("elfu_mFromElf: Failed to load file.\n");