an ELF sharable library or a linux style of shared library. */
/* Disclaimer: I have never seen any AT&T source code for SVr4, nor have
- I ever taken any courses on internals. This program was developed using
- information available through the book "UNIX SYSTEM V RELEASE 4,
- Programmers guide: Ansi C and Programming Support Tools", which did
- a more than adequate job of explaining everything required to get this
- working. */
+ I ever taken any courses on internals. This program was developed using
+ information available through the book "UNIX SYSTEM V RELEASE 4,
+ Programmers guide: Ansi C and Programming Support Tools", which did
+ a more than adequate job of explaining everything required to get this
+ working. */
+
+/* Some SPARC opcodes we need to use for self-modifying code. */
+#define OPCODE_NOP 0x01000000 /* nop */
+#define OPCODE_CALL 0x40000000 /* call ?; add PC-rel word address */
+#define OPCODE_SETHI_G1 0x03000000 /* sethi ?, %g1; add value>>10 */
+#define OPCODE_JMP_G1 0x81c06000 /* jmp %g1+?; add lo 10 bits of value */
+#define OPCODE_SAVE_SP 0x9de3bfa8 /* save %sp, -(16+6)*4, %sp */
+#define OPCODE_BA 0x30800000 /* b,a ?; add PC-rel word address */
extern int _dl_linux_resolve(void);
-unsigned int _dl_linux_resolver(unsigned int reloc_entry, unsigned int * plt)
+unsigned long
+_dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry)
{
- int reloc_type;
- Elf32_Rela * this_reloc;
- char * strtab;
- Elf32_Sym * symtab;
- Elf32_Rela * rel_addr;
- struct elf_resolve * tpnt;
- int symtab_index;
- char * new_addr;
- char ** got_addr;
- unsigned int instr_addr;
- tpnt = (struct elf_resolve *) plt[2];
-
- rel_addr = (Elf32_Rela *)tpnt->dynamic_info[DT_JMPREL];
-
- /*
- * Generate the correct relocation index into the .rela.plt section.
- */
- reloc_entry = (reloc_entry >> 10) - 0xc;
-
- this_reloc = (Elf32_Rela *) ((char *) rel_addr + reloc_entry);
-
- reloc_type = ELF32_R_TYPE(this_reloc->r_info);
- symtab_index = ELF32_R_SYM(this_reloc->r_info);
-
- symtab = (Elf32_Sym *)tpnt->dynamic_info[DT_SYMTAB];
- strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
-
-#ifdef __SUPPORT_LD_DEBUG__
- if (_dl_debug_symbols) {
- _dl_dprintf(2, "tpnt = %x\n", tpnt);
- _dl_dprintf(2, "reloc = %x\n", this_reloc);
- _dl_dprintf(2, "symtab = %x\n", symtab);
- _dl_dprintf(2, "strtab = %x\n", strtab);
- }
+ int reloc_type;
+ ELF_RELOC *this_reloc;
+ char *strtab;
+ ElfW(Sym) *symtab;
+ int symtab_index;
+ char *rel_addr;
+ char *new_addr;
+ char **got_addr;
+ ElfW(Addr) instr_addr;
+ char *symname;
+
+ rel_addr = (char *)tpnt->dynamic_info[DT_JMPREL];
+ /*
+ * Generate the correct relocation index into the .rela.plt section.
+ */
+ reloc_entry = (reloc_entry >> 10) - 0xc;
+
+ this_reloc = (ELF_RELOC *)(rel_addr + reloc_entry);
+ reloc_type = ELF_R_TYPE(this_reloc->r_info);
+ symtab_index = ELF_R_SYM(this_reloc->r_info);
+
+ symtab = (ElfW(Sym) *)tpnt->dynamic_info[DT_SYMTAB];
+ strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
+ symname = strtab + symtab[symtab_index].st_name;
+
+ if (unlikely(reloc_type != R_SPARC_JMP_SLOT)) {
+ _dl_dprintf(2, "%s: Incorrect relocation type in jump relocations\n",
+ _dl_progname);
+ _dl_exit(1);
+ }
+
+ /* Address of the jump instruction to fix up. */
+ instr_addr = (this_reloc->r_offset + tpnt->loadaddr);
+ got_addr = (char **)instr_addr;
+
+ /* Get the address of the GOT entry */
+ new_addr = _dl_find_hash(symname, tpnt->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT);
+ if (unlikely(!new_addr)) {
+ _dl_dprintf(2, "%s: Can't resolve symbol '%s'\n", _dl_progname, symname);
+ _dl_exit(1);
+ }
+
+#if defined (__SUPPORT_LD_DEBUG__)
+ if ((unsigned long)got_addr < 0x40000000) {
+ if (_dl_debug_bindings) {
+ _dl_dprintf(_dl_debug_file, "\nresolve function: %s", symname);
+ if (_dl_debug_detail)
+ _dl_dprintf(_dl_debug_file,
+ "\tpatched: %x ==> %x @ %x\n",
+ *got_addr, new_addr, got_addr);
+ }
+ }
+ if (!_dl_debug_nofixups)
#endif
+ {
+ got_addr[1] = (char *) (0x03000000 | (((unsigned int) new_addr >> 10) & 0x3fffff));
+ got_addr[2] = (char *) (0x81c06000 | ((unsigned int) new_addr & 0x3ff));
+ }
+ return (unsigned long)new_addr;
+}
+
+static int
+_dl_parse(struct elf_resolve *tpnt, struct dyn_elf *scope,
+ unsigned long rel_addr, unsigned long rel_size,
+ int (*reloc_fnc)(struct elf_resolve *tpnt, struct dyn_elf *scope,
+ ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab))
+{
+ unsigned int i;
+ char *strtab;
+ ElfW(Sym) *symtab;
+ ELF_RELOC *rpnt;
+ int symtab_index;
- if (unlikely(reloc_type != R_SPARC_JMP_SLOT)) {
- _dl_dprintf(2, "%s: incorrect relocation type in jump relocations (%d)\n",
- _dl_progname, reloc_type);
- _dl_exit(30);
- };
+ /* Parse the relocation information. */
+ rpnt = (ELF_RELOC *)rel_addr;
+ rel_size /= sizeof(ELF_RELOC);
- /* Address of jump instruction to fix up */
- instr_addr = ((int)this_reloc->r_offset + (int)tpnt->loadaddr);
- got_addr = (char **) instr_addr;
+ symtab = (ElfW(Sym) *)tpnt->dynamic_info[DT_SYMTAB];
+ strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
-#ifdef __SUPPORT_LD_DEBUG__
- if (_dl_debug_symbols) {
- _dl_dprintf(2, "symtab_index %x\n", symtab_index);
+ for (i = 0; i < rel_size; i++, rpnt++) {
+ int res;
- _dl_dprintf(2, "Resolving symbol %s\n",
- strtab + symtab[symtab_index].st_name);
- }
-#endif
+ symtab_index = ELF_R_SYM(rpnt->r_info);
- /* Get the address of the GOT entry */
- new_addr = _dl_find_hash(strtab + symtab[symtab_index].st_name,
- tpnt->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT);
- if(unlikely(!new_addr)) {
- _dl_dprintf(2, "%s: can't resolve symbol '%s'\n",
- _dl_progname, strtab + symtab[symtab_index].st_name);
- _dl_exit(31);
- };
+ debug_sym(symtab, strtab, symtab_index);
+ debug_reloc(symtab, strtab, rpnt);
+ res = reloc_fnc(tpnt, scope, rpnt, symtab, strtab);
+
+ if (res == 0)
+ continue;
+
+ _dl_dprintf(2, "\n%s: ", _dl_progname);
+
+ if (symtab_index)
+ _dl_dprintf(2, "symbol '%s': ",
+ strtab + symtab[symtab_index].st_name);
+
+ if (unlikely(res < 0)) {
+ int reloc_type = ELF_R_TYPE(rpnt->r_info);
+
+ _dl_dprintf(2, "can't handle reloc type "
#if defined (__SUPPORT_LD_DEBUG__)
- if ((unsigned long) got_addr < 0x40000000)
- {
- if (_dl_debug_bindings)
- {
- _dl_dprintf(_dl_debug_file, "\nresolve function: %s",
- strtab + symtab[symtab_index].st_name);
- if(_dl_debug_detail) _dl_dprintf(_dl_debug_file,
- "\tpatch %x ==> %x @ %x", *got_addr, new_addr, got_addr);
+ "%s\n", _dl_reltypes(reloc_type));
+#else
+ "%x\n", reloc_type);
+#endif
+ _dl_exit(-res);
+ } else if (unlikely(res > 0)) {
+ _dl_dprintf(2, "can't resolve symbol\n");
+ return res;
}
}
- if (!_dl_debug_nofixups) {
- got_addr[1] = (char *) (0x03000000 | (((unsigned int) new_addr >> 10) & 0x3fffff));
- got_addr[2] = (char *) (0x81c06000 | ((unsigned int) new_addr & 0x3ff));
+
+ return 0;
+}
+
+static int
+_dl_do_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope,
+ ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab)
+{
+ int reloc_type;
+ int symtab_index;
+ char *symname;
+ ElfW(Sym) *sym;
+ ElfW(Addr) *reloc_addr;
+ ElfW(Addr) symbol_addr;
+#if defined (__SUPPORT_LD_DEBUG__)
+ ElfW(Addr) old_val;
+#endif
+
+ reloc_addr = (ElfW(Addr)*)(tpnt->loadaddr + (unsigned long)rpnt->r_offset);
+ reloc_type = ELF_R_TYPE(rpnt->r_info);
+ symtab_index = ELF_R_SYM(rpnt->r_info);
+ sym = &symtab[symtab_index];
+ symbol_addr = 0;
+ symname = strtab + sym->st_name;
+
+ if (symtab_index) {
+ symbol_addr = (ElfW(Addr))_dl_find_hash(symname, scope, tpnt,
+ elf_machine_type_class(reloc_type));
+ /*
+ * We want to allow undefined references to weak symbols - this
+ * might have been intentional. We should not be linking local
+ * symbols here, so all bases should be covered.
+ */
+ if (unlikely(!symbol_addr && ELF_ST_BIND(sym->st_info) != STB_WEAK)) {
+ _dl_dprintf(2, "%s: can't resolve symbol '%s'\n", _dl_progname, symname);
+ _dl_exit(1);
+ }
}
-#else
- got_addr[1] = (char *) (0x03000000 | (((unsigned int) new_addr >> 10) & 0x3fffff));
- got_addr[2] = (char *) (0x81c06000 | ((unsigned int) new_addr & 0x3ff));
+
+#if defined (__SUPPORT_LD_DEBUG__)
+ old_val = *reloc_addr;
#endif
- _dl_dprintf(2, "Address = %x\n",new_addr);
- _dl_exit(32);
+ symbol_addr += rpnt->r_addend; /* Assume copy relocs have zero addend. */
+
+ switch (reloc_type) {
+ case R_SPARC_NONE:
+ break;
+
+#if 0 /* these dont really seem to be useful */
+ case R_SPARC_8:
+ *(char *) reloc_addr = symbol_addr;
+ break;
+ case R_SPARC_16:
+ *(short *) reloc_addr = symbol_addr;
+ break;
+ case R_SPARC_DISP8:
+ *(char *) reloc_addr = (symbol_addr) - (Elf32_Addr) reloc_addr;
+ break;
+ case R_SPARC_DISP16:
+ *(short *) reloc_addr = (symbol_addr) - (Elf32_Addr) reloc_addr;
+ break;
+#endif
- return (unsigned int) new_addr;
-}
+ case R_SPARC_DISP32:
+ *reloc_addr = symbol_addr - (unsigned int) reloc_addr;
+ break;
+
+ case R_SPARC_LO10:
+ if (!symbol_addr)
+ symbol_addr = tpnt->loadaddr + rpnt->r_addend;
+ else
+ symbol_addr += rpnt->r_addend;
+ *reloc_addr = (*reloc_addr & ~0x3ff)|(symbol_addr & 0x3ff);
+ break;
+
+ case R_SPARC_GLOB_DAT:
+ case R_SPARC_32:
+ *reloc_addr = symbol_addr;
+ break;
+
+ case R_SPARC_JMP_SLOT:
+/*
+value = symbol_addr;
+value += reloc->r_addend;
+disp = value - reloc_addr;
+reloc_addr[1] = OPCODE_JMP_G1 | (value & 0x3ff);
+reloc_addr[0] = OPCODE_SETHI_G1 | (value >> 10);
+ reloc_addr[1] = OPCODE_JMP_G1 | ((symbol_addr-(Elf32_Addr)reloc_addr) & 0x3ff);
+ reloc_addr[0] = OPCODE_SETHI_G1 | ((symbol_addr-(Elf32_Addr)reloc_addr) >> 10);
+*/
+ reloc_addr[1] = 0x03000000 | ((symbol_addr >> 10) & 0x3fffff);
+ reloc_addr[2] = 0x81c06000 | (symbol_addr & 0x3ff);
+ break;
+
+ case R_SPARC_RELATIVE:
+ *reloc_addr += tpnt->loadaddr + rpnt->r_addend;
+ break;
+
+ case R_SPARC_WDISP30:
+ *reloc_addr = (*reloc_addr & 0xc0000000)|
+ ((symbol_addr - (unsigned int) reloc_addr) >> 2);
+ break;
+
+ case R_SPARC_HI22:
+ if (!symbol_addr)
+ symbol_addr = tpnt->loadaddr + rpnt->r_addend;
+ else
+ symbol_addr += rpnt->r_addend;
+ *reloc_addr = (*reloc_addr & 0xffc00000) | (symbol_addr >> 10);
+ break;
+
+ case R_SPARC_COPY:
+ if (symbol_addr) {
+#if defined (__SUPPORT_LD_DEBUG__)
+ if (_dl_debug_move)
+ _dl_dprintf(_dl_debug_file,
+ "\t%s move %d bytes from %x to %x\n",
+ symname, sym->st_size,
+ symbol_addr, reloc_addr);
+#endif
+
+ _dl_memcpy((char *)reloc_addr,
+ (char *)symbol_addr,
+ sym->st_size);
+ } else
+ _dl_dprintf(_dl_debug_file, "no symbol_addr to copy !?\n");
+ break;
+ default:
+ return -1; /* Calls _dl_exit(1). */
+ }
-void _dl_parse_lazy_relocation_information(struct dyn_elf *arg_rpnt,
- unsigned long rel_addr, unsigned long rel_size)
-{
- int i;
- char * strtab;
- int reloc_type;
- int symtab_index;
- Elf32_Sym * symtab;
- Elf32_Rela * rpnt;
- unsigned int * reloc_addr;
- struct elf_resolve * tpnt = arg_rpnt->dyn;
-
- /* Now parse the relocation information */
- rpnt = (Elf32_Rela *)rel_addr;
-
- symtab = (Elf32_Sym *)tpnt->dynamic_info[DT_SYMTAB];
- strtab = ( char *)tpnt->dynamic_info[DT_STRTAB];
-
- for(i=0; i< rel_size; i += sizeof(Elf32_Rela), rpnt++){
- reloc_addr = (int *) (tpnt->loadaddr + (int)rpnt->r_offset);
- reloc_type = ELF32_R_TYPE(rpnt->r_info);
- symtab_index = ELF32_R_SYM(rpnt->r_info);
-
- switch(reloc_type){
- case R_SPARC_NONE:
- break;
- case R_SPARC_JMP_SLOT:
- break;
- default:
- _dl_dprintf(2, "%s: (LAZY) can't handle reloc type ", _dl_progname);
#if defined (__SUPPORT_LD_DEBUG__)
- _dl_dprintf(2, "%s ", _dl_reltypes_tab[reloc_type]);
+ if (_dl_debug_reloc && _dl_debug_detail)
+ _dl_dprintf(_dl_debug_file, "\tpatched: %x ==> %x @ %x\n",
+ old_val, *reloc_addr, reloc_addr);
#endif
- if(symtab_index) _dl_dprintf(2, "'%s'\n",
- strtab + symtab[symtab_index].st_name);
- _dl_exit(33);
- };
- };
+
+ return 0;
}
-int _dl_parse_relocation_information(struct dyn_elf *arg_rpnt,
- unsigned long rel_addr, unsigned long rel_size)
+static int
+_dl_do_lazy_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope,
+ ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab)
{
- int i;
- char * strtab;
- int reloc_type;
- int goof = 0;
- Elf32_Sym * symtab;
- Elf32_Rela * rpnt;
- unsigned int * reloc_addr;
- unsigned int symbol_addr;
- int symtab_index;
- struct elf_resolve * tpnt = arg_rpnt->dyn;
- /* Now parse the relocation information */
-
- rpnt = (Elf32_Rela *)rel_addr;
-
- symtab = (Elf32_Sym *)tpnt->dynamic_info[DT_SYMTAB];
- strtab = ( char *)tpnt->dynamic_info[DT_STRTAB];
-
- for(i=0; i< rel_size; i+= sizeof(Elf32_Rela), rpnt++){
- reloc_addr = (int *) (tpnt->loadaddr + (int)rpnt->r_offset);
- reloc_type = ELF32_R_TYPE(rpnt->r_info);
- symtab_index = ELF32_R_SYM(rpnt->r_info);
- symbol_addr = 0;
-
- if(symtab_index) {
-
- symbol_addr = (unsigned int)
- _dl_find_hash(strtab + symtab[symtab_index].st_name,
- tpnt->symbol_scope, tpnt, elf_machine_type_class(reloc_type));
-
- if(!symbol_addr &&
- ELF32_ST_BIND(symtab [symtab_index].st_info) != STB_WEAK) {
- _dl_dprintf (2, "%s: can't resolve symbol '%s'\n",
- _dl_progname, strtab + symtab[symtab_index].st_name);
- _dl_exit (1);
- };
- };
- switch(reloc_type){
- case R_SPARC_NONE:
- break;
- case R_SPARC_32:
- *reloc_addr = symbol_addr + rpnt->r_addend;
- break;
- case R_SPARC_DISP32:
- *reloc_addr = symbol_addr + rpnt->r_addend - (unsigned int) reloc_addr;
- break;
- case R_SPARC_GLOB_DAT:
- *reloc_addr = symbol_addr + rpnt->r_addend;
- break;
- case R_SPARC_JMP_SLOT:
- reloc_addr[1] = 0x03000000 | ((symbol_addr >> 10) & 0x3fffff);
- reloc_addr[2] = 0x81c06000 | (symbol_addr & 0x3ff);
- break;
- case R_SPARC_RELATIVE:
- *reloc_addr += (unsigned int) tpnt->loadaddr + rpnt->r_addend;
- break;
- case R_SPARC_HI22:
- if (!symbol_addr)
- symbol_addr = tpnt->loadaddr + rpnt->r_addend;
- else
- symbol_addr += rpnt->r_addend;
- *reloc_addr = (*reloc_addr & 0xffc00000)|(symbol_addr >> 10);
- break;
- case R_SPARC_LO10:
- if (!symbol_addr)
- symbol_addr = tpnt->loadaddr + rpnt->r_addend;
- else
- symbol_addr += rpnt->r_addend;
- *reloc_addr = (*reloc_addr & ~0x3ff)|(symbol_addr & 0x3ff);
- break;
- case R_SPARC_WDISP30:
- *reloc_addr = (*reloc_addr & 0xc0000000)|
- ((symbol_addr - (unsigned int) reloc_addr) >> 2);
- break;
- case R_SPARC_COPY:
- _dl_memcpy((void *) reloc_addr, (void *) symbol_addr, symtab[symtab_index].st_size);
- break;
- default:
- _dl_dprintf(2, "%s: can't handle reloc type ", _dl_progname);
+ int reloc_type;
+ int symtab_index;
+ ElfW(Addr) *reloc_addr;
+#if defined (__SUPPORT_LD_DEBUG__)
+ ElfW(Addr) old_val;
+#endif
+
+ (void)scope;
+ symtab_index = ELF_R_SYM(rpnt->r_info);
+ (void)strtab;
+
+ reloc_addr = (ElfW(Addr)*)(tpnt->loadaddr + rpnt->r_offset);
+ reloc_type = ELF_R_TYPE(rpnt->r_info);
+
#if defined (__SUPPORT_LD_DEBUG__)
- _dl_dprintf(2, "%s ", _dl_reltypes_tab[reloc_type]);
+ old_val = *reloc_addr;
#endif
- if (symtab_index)
- _dl_dprintf(2, "'%s'\n", strtab + symtab[symtab_index].st_name);
- _dl_exit(34);
- };
- };
- return goof;
+ switch (reloc_type) {
+ case R_SPARC_NONE:
+ break;
+ case R_SPARC_JMP_SLOT:
+ break;
+ default:
+ _dl_exit(1);
+ }
+
+#if defined (__SUPPORT_LD_DEBUG__)
+ if (_dl_debug_reloc && _dl_debug_detail)
+ _dl_dprintf(_dl_debug_file, "\tpatched_lazy: %x ==> %x @ %x\n",
+ old_val, *reloc_addr, reloc_addr);
+#endif
+
+ return 0;
+}
+
+void
+_dl_parse_lazy_relocation_information(struct dyn_elf *rpnt,
+ unsigned long rel_addr,
+ unsigned long rel_size)
+{
+// (void)_dl_parse(rpnt->dyn, NULL, rel_addr, rel_size, _dl_do_lazy_reloc);
+ _dl_parse_relocation_information(rpnt, rel_addr, rel_size);
+}
+
+int
+_dl_parse_relocation_information(struct dyn_elf *rpnt,
+ unsigned long rel_addr,
+ unsigned long rel_size)
+{
+ return _dl_parse(rpnt->dyn, rpnt->dyn->symbol_scope, rel_addr, rel_size, _dl_do_reloc);
}
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