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- static inline bool FUNC(patch_vdso)(const char *path, void *vdso)
- {
- const ELF(Ehdr) *ehdr = vdso;
- void *shdrs;
- ELF(Shdr) *shdr;
- char *shstrtab, *name;
- uint16_t sh_count, sh_entsize, i;
- unsigned int local_gotno, symtabno, gotsym;
- ELF(Dyn) *dyn = NULL;
- shdrs = vdso + FUNC(swap_uint)(ehdr->e_shoff);
- sh_count = swap_uint16(ehdr->e_shnum);
- sh_entsize = swap_uint16(ehdr->e_shentsize);
- shdr = shdrs + (sh_entsize * swap_uint16(ehdr->e_shstrndx));
- shstrtab = vdso + FUNC(swap_uint)(shdr->sh_offset);
- for (i = 0; i < sh_count; i++) {
- shdr = shdrs + (i * sh_entsize);
- name = shstrtab + swap_uint32(shdr->sh_name);
-
- switch (swap_uint32(shdr->sh_type)) {
- case SHT_REL:
- case SHT_RELA:
- fprintf(stderr,
- "%s: '%s' contains relocation sections\n",
- program_name, path);
- return false;
- case SHT_DYNAMIC:
- dyn = vdso + FUNC(swap_uint)(shdr->sh_offset);
- break;
- }
-
- if (strcmp(name, ".MIPS.abiflags") == 0) {
- fprintf(stderr,
- "%s: '%s' already contains a '.MIPS.abiflags' section\n",
- program_name, path);
- return false;
- }
- if (strcmp(name, ".mips_abiflags") == 0) {
- strcpy(name, ".MIPS.abiflags");
- shdr->sh_type = swap_uint32(SHT_MIPS_ABIFLAGS);
- shdr->sh_entsize = shdr->sh_size;
- }
- }
-
- if (dyn) {
- local_gotno = symtabno = gotsym = 0;
- while (FUNC(swap_uint)(dyn->d_tag) != DT_NULL) {
- switch (FUNC(swap_uint)(dyn->d_tag)) {
-
- case DT_MIPS_LOCAL_GOTNO:
- local_gotno = FUNC(swap_uint)(dyn->d_un.d_val);
- break;
-
- case DT_MIPS_SYMTABNO:
- symtabno = FUNC(swap_uint)(dyn->d_un.d_val);
- break;
-
- case DT_MIPS_GOTSYM:
- gotsym = FUNC(swap_uint)(dyn->d_un.d_val);
- break;
- }
- dyn++;
- }
- if (local_gotno > 2 || symtabno - gotsym) {
- fprintf(stderr,
- "%s: '%s' contains unexpected GOT entries\n",
- program_name, path);
- return false;
- }
- }
- return true;
- }
- static inline bool FUNC(get_symbols)(const char *path, void *vdso)
- {
- const ELF(Ehdr) *ehdr = vdso;
- void *shdrs, *symtab;
- ELF(Shdr) *shdr;
- const ELF(Sym) *sym;
- char *strtab, *name;
- uint16_t sh_count, sh_entsize, st_count, st_entsize, i, j;
- uint64_t offset;
- uint32_t flags;
- shdrs = vdso + FUNC(swap_uint)(ehdr->e_shoff);
- sh_count = swap_uint16(ehdr->e_shnum);
- sh_entsize = swap_uint16(ehdr->e_shentsize);
- for (i = 0; i < sh_count; i++) {
- shdr = shdrs + (i * sh_entsize);
- if (swap_uint32(shdr->sh_type) == SHT_SYMTAB)
- break;
- }
- if (i == sh_count) {
- fprintf(stderr, "%s: '%s' has no symbol table\n", program_name,
- path);
- return false;
- }
-
- flags = swap_uint32(ehdr->e_flags);
- if (elf_class == ELFCLASS64)
- elf_abi = ABI_N64;
- else if (flags & EF_MIPS_ABI2)
- elf_abi = ABI_N32;
- else
- elf_abi = ABI_O32;
-
- symtab = vdso + FUNC(swap_uint)(shdr->sh_offset);
- st_entsize = FUNC(swap_uint)(shdr->sh_entsize);
- st_count = FUNC(swap_uint)(shdr->sh_size) / st_entsize;
-
- shdr = shdrs + (swap_uint32(shdr->sh_link) * sh_entsize);
- strtab = vdso + FUNC(swap_uint)(shdr->sh_offset);
-
- for (i = 0; vdso_symbols[i].name; i++) {
- if (!(vdso_symbols[i].abis & elf_abi))
- continue;
- for (j = 0; j < st_count; j++) {
- sym = symtab + (j * st_entsize);
- name = strtab + swap_uint32(sym->st_name);
- if (!strcmp(name, vdso_symbols[i].name)) {
- offset = FUNC(swap_uint)(sym->st_value);
- fprintf(out_file,
- "\t.%s = 0x%" PRIx64 ",\n",
- vdso_symbols[i].offset_name, offset);
- break;
- }
- }
- if (j == st_count) {
- fprintf(stderr,
- "%s: '%s' is missing required symbol '%s'\n",
- program_name, path, vdso_symbols[i].name);
- return false;
- }
- }
- return true;
- }
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