int reltype);
int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset,
- unsigned int type, struct symbol *sym, int addend)
+ unsigned int type, struct symbol *sym, long addend)
{
struct reloc *reloc;
return 0;
}
-int elf_add_reloc_to_insn(struct elf *elf, struct section *sec,
- unsigned long offset, unsigned int type,
- struct section *insn_sec, unsigned long insn_off)
+/*
+ * Ensure that any reloc section containing references to @sym is marked
+ * changed such that it will get re-generated in elf_rebuild_reloc_sections()
+ * with the new symbol index.
+ */
+static void elf_dirty_reloc_sym(struct elf *elf, struct symbol *sym)
+{
+ struct section *sec;
+
+ list_for_each_entry(sec, &elf->sections, list) {
+ struct reloc *reloc;
+
+ if (sec->changed)
+ continue;
+
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ if (reloc->sym == sym) {
+ sec->changed = true;
+ break;
+ }
+ }
+ }
+}
+
+/*
+ * Move the first global symbol, as per sh_info, into a new, higher symbol
+ * index. This fees up the shndx for a new local symbol.
+ */
+static int elf_move_global_symbol(struct elf *elf, struct section *symtab,
+ struct section *symtab_shndx)
{
+ Elf_Data *data, *shndx_data = NULL;
+ Elf32_Word first_non_local;
struct symbol *sym;
- int addend;
+ Elf_Scn *s;
- if (insn_sec->sym) {
- sym = insn_sec->sym;
- addend = insn_off;
+ first_non_local = symtab->sh.sh_info;
- } else {
- /*
- * The Clang assembler strips section symbols, so we have to
- * reference the function symbol instead:
- */
- sym = find_symbol_containing(insn_sec, insn_off);
- if (!sym) {
- /*
- * Hack alert. This happens when we need to reference
- * the NOP pad insn immediately after the function.
- */
- sym = find_symbol_containing(insn_sec, insn_off - 1);
+ sym = find_symbol_by_index(elf, first_non_local);
+ if (!sym) {
+ WARN("no non-local symbols !?");
+ return first_non_local;
+ }
+
+ s = elf_getscn(elf->elf, symtab->idx);
+ if (!s) {
+ WARN_ELF("elf_getscn");
+ return -1;
+ }
+
+ data = elf_newdata(s);
+ if (!data) {
+ WARN_ELF("elf_newdata");
+ return -1;
+ }
+
+ data->d_buf = &sym->sym;
+ data->d_size = sizeof(sym->sym);
+ data->d_align = 1;
+ data->d_type = ELF_T_SYM;
+
+ sym->idx = symtab->sh.sh_size / sizeof(sym->sym);
+ elf_dirty_reloc_sym(elf, sym);
+
+ symtab->sh.sh_info += 1;
+ symtab->sh.sh_size += data->d_size;
+ symtab->changed = true;
+
+ if (symtab_shndx) {
+ s = elf_getscn(elf->elf, symtab_shndx->idx);
+ if (!s) {
+ WARN_ELF("elf_getscn");
+ return -1;
}
- if (!sym) {
- WARN("can't find symbol containing %s+0x%lx", insn_sec->name, insn_off);
+ shndx_data = elf_newdata(s);
+ if (!shndx_data) {
+ WARN_ELF("elf_newshndx_data");
return -1;
}
- addend = insn_off - sym->offset;
+ shndx_data->d_buf = &sym->sec->idx;
+ shndx_data->d_size = sizeof(Elf32_Word);
+ shndx_data->d_align = 4;
+ shndx_data->d_type = ELF_T_WORD;
+
+ symtab_shndx->sh.sh_size += 4;
+ symtab_shndx->changed = true;
+ }
+
+ return first_non_local;
+}
+
+static struct symbol *
+elf_create_section_symbol(struct elf *elf, struct section *sec)
+{
+ struct section *symtab, *symtab_shndx;
+ Elf_Data *shndx_data = NULL;
+ struct symbol *sym;
+ Elf32_Word shndx;
+
+ symtab = find_section_by_name(elf, ".symtab");
+ if (symtab) {
+ symtab_shndx = find_section_by_name(elf, ".symtab_shndx");
+ if (symtab_shndx)
+ shndx_data = symtab_shndx->data;
+ } else {
+ WARN("no .symtab");
+ return NULL;
+ }
+
+ sym = malloc(sizeof(*sym));
+ if (!sym) {
+ perror("malloc");
+ return NULL;
+ }
+ memset(sym, 0, sizeof(*sym));
+
+ sym->idx = elf_move_global_symbol(elf, symtab, symtab_shndx);
+ if (sym->idx < 0) {
+ WARN("elf_move_global_symbol");
+ return NULL;
+ }
+
+ sym->name = sec->name;
+ sym->sec = sec;
+
+ // st_name 0
+ sym->sym.st_info = GELF_ST_INFO(STB_LOCAL, STT_SECTION);
+ // st_other 0
+ // st_value 0
+ // st_size 0
+ shndx = sec->idx;
+ if (shndx >= SHN_UNDEF && shndx < SHN_LORESERVE) {
+ sym->sym.st_shndx = shndx;
+ if (!shndx_data)
+ shndx = 0;
+ } else {
+ sym->sym.st_shndx = SHN_XINDEX;
+ if (!shndx_data) {
+ WARN("no .symtab_shndx");
+ return NULL;
+ }
+ }
+
+ if (!gelf_update_symshndx(symtab->data, shndx_data, sym->idx, &sym->sym, shndx)) {
+ WARN_ELF("gelf_update_symshndx");
+ return NULL;
+ }
+
+ elf_add_symbol(elf, sym);
+
+ return sym;
+}
+
+int elf_add_reloc_to_insn(struct elf *elf, struct section *sec,
+ unsigned long offset, unsigned int type,
+ struct section *insn_sec, unsigned long insn_off)
+{
+ struct symbol *sym = insn_sec->sym;
+ int addend = insn_off;
+
+ if (!sym) {
+ /*
+ * Due to how weak functions work, we must use section based
+ * relocations. Symbol based relocations would result in the
+ * weak and non-weak function annotations being overlaid on the
+ * non-weak function after linking.
+ */
+ sym = elf_create_section_symbol(elf, insn_sec);
+ if (!sym)
+ return -1;
+
+ insn_sec->sym = sym;
}
return elf_add_reloc(elf, sec, offset, type, sym, addend);
projects / linux-2.6-microblaze.git / blobdiff