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-rw-r--r--ldso/ldso/arc/elfinterp.c279
1 files changed, 279 insertions, 0 deletions
diff --git a/ldso/ldso/arc/elfinterp.c b/ldso/ldso/arc/elfinterp.c
new file mode 100644
index 000000000..a3d741b65
--- /dev/null
+++ b/ldso/ldso/arc/elfinterp.c
@@ -0,0 +1,279 @@
+/*
+ * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
+ *
+ * Lots of code copied from ../i386/elfinterp.c, so:
+ * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
+ * David Engel, Hongjiu Lu and Mitch D'Souza
+ * Copyright (C) 2001-2002, Erik Andersen
+ * All rights reserved.
+ *
+ * Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
+ */
+#include "ldso.h"
+
+#define ARC_PLT_SIZE 12
+
+unsigned long
+_dl_linux_resolver(struct elf_resolve *tpnt, unsigned int plt_pc)
+{
+ ELF_RELOC *this_reloc, *rel_base;
+ char *strtab, *symname, *new_addr;
+ ElfW(Sym) *symtab;
+ int symtab_index;
+ unsigned int *got_addr;
+ unsigned long plt_base;
+ int plt_idx;
+
+ /* start of .rela.plt */
+ rel_base = (ELF_RELOC *)(tpnt->dynamic_info[DT_JMPREL]);
+
+ /* starts of .plt (addr of PLT0) */
+ plt_base = tpnt->dynamic_info[DT_PLTGOT];
+
+ /*
+ * compute the idx of the yet-unresolved PLT entry in .plt
+ * Same idx will be used to find the relo entry in .rela.plt
+ */
+ plt_idx = (plt_pc - plt_base)/ARC_PLT_SIZE - 2; /* ignoring 2 dummy PLTs */
+
+ this_reloc = rel_base + plt_idx;
+
+ symtab_index = ELF_R_SYM(this_reloc->r_info);
+ symtab = (ElfW(Sym) *)(intptr_t) (tpnt->dynamic_info[DT_SYMTAB]);
+ strtab = (char *) (tpnt->dynamic_info[DT_STRTAB]);
+ symname= strtab + symtab[symtab_index].st_name;
+
+ /* relo-offset to fixup, shd be a .got entry */
+ got_addr = (unsigned int *)(this_reloc->r_offset + tpnt->loadaddr);
+
+ /* Get the address of the GOT entry */
+ new_addr = _dl_find_hash(symname, &_dl_loaded_modules->symbol_scope, tpnt,
+ ELF_RTYPE_CLASS_PLT, NULL);
+
+ 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 (_dl_debug_bindings) {
+ _dl_dprintf(_dl_debug_file, "\nresolve function: %s", symname);
+ if(_dl_debug_detail)
+ _dl_dprintf(_dl_debug_file, "\n\tpatched %x ==> %pc @ %pl\n",
+ *got_addr, new_addr, got_addr);
+ }
+
+ if (!_dl_debug_nofixups)
+ *got_addr = (unsigned int)new_addr;
+#else
+ /* Update the .got entry with the runtime address of symbol */
+ *got_addr = (unsigned int)new_addr;
+#endif
+
+ /*
+ * Return the new addres, where the asm trampoline will jump to
+ * after re-setting up the orig args
+ */
+ return (unsigned long) new_addr;
+}
+
+
+static int
+_dl_do_reloc(struct elf_resolve *tpnt, struct r_scope_elem *scope,
+ ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab)
+{
+ int reloc_type;
+ int symtab_index;
+ char *symname;
+ unsigned long *reloc_addr;
+ unsigned long symbol_addr;
+#if defined __SUPPORT_LD_DEBUG__
+ unsigned long old_val = 0;
+#endif
+ struct symbol_ref sym_ref;
+
+ reloc_addr = (unsigned long *)(tpnt->loadaddr + rpnt->r_offset);
+ reloc_type = ELF_R_TYPE(rpnt->r_info);
+ symtab_index = ELF_R_SYM(rpnt->r_info);
+ symbol_addr = 0;
+
+ sym_ref.sym = &symtab[symtab_index];
+ sym_ref.tpnt = NULL;
+
+#if defined __SUPPORT_LD_DEBUG__
+ if (reloc_addr)
+ old_val = *reloc_addr;
+#endif
+
+ if (symtab_index) {
+ symname = strtab + symtab[symtab_index].st_name;
+ symbol_addr = (unsigned long) _dl_find_hash(symname, scope, tpnt,
+ elf_machine_type_class(reloc_type), &sym_ref);
+
+ /*
+ * 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(symtab[symtab_index].st_info) != STB_WEAK)) {
+ /* Non-fatal if called from dlopen, hence different ret code */
+ return 1;
+ }
+ } else if (reloc_type == R_ARC_RELATIVE ) {
+ *reloc_addr += tpnt->loadaddr;
+ goto log_entry;
+ }
+
+ switch (reloc_type) {
+ case R_ARC_32:
+ *reloc_addr += symbol_addr + rpnt->r_addend;
+ break;
+ case R_ARC_PC32:
+ *reloc_addr += symbol_addr + rpnt->r_addend - (unsigned long) reloc_addr;
+ break;
+ case R_ARC_GLOB_DAT:
+ case R_ARC_JMP_SLOT:
+ *reloc_addr = symbol_addr;
+ break;
+ case R_ARC_COPY:
+ _dl_memcpy((void *) reloc_addr,(void *) symbol_addr,
+ symtab[symtab_index].st_size);
+ break;
+ default:
+ return -1;
+ }
+
+log_entry:
+#if defined __SUPPORT_LD_DEBUG__
+ if(_dl_debug_detail)
+ _dl_dprintf(_dl_debug_file,"\tpatched: %lx ==> %lx @ %pl: addend %x ",
+ old_val, *reloc_addr, reloc_addr, rpnt->r_addend);
+#endif
+
+ return 0;
+}
+
+static int
+_dl_do_lazy_reloc(struct elf_resolve *tpnt, struct r_scope_elem *scope,
+ ELF_RELOC *rpnt)
+{
+ int reloc_type;
+ unsigned long *reloc_addr;
+#if defined __SUPPORT_LD_DEBUG__
+ unsigned long old_val;
+#endif
+
+ reloc_addr = (unsigned long *)(tpnt->loadaddr + rpnt->r_offset);
+ reloc_type = ELF_R_TYPE(rpnt->r_info);
+
+#if defined __SUPPORT_LD_DEBUG__
+ old_val = *reloc_addr;
+#endif
+
+ switch (reloc_type) {
+ case R_ARC_JMP_SLOT:
+ *reloc_addr += tpnt->loadaddr;
+ break;
+ default:
+ return -1;
+ }
+
+#if defined __SUPPORT_LD_DEBUG__
+ if(_dl_debug_reloc && _dl_debug_detail)
+ _dl_dprintf(_dl_debug_file, "\tpatched: %lx ==> %lx @ %pl\n",
+ old_val, *reloc_addr, reloc_addr);
+#endif
+
+ return 0;
+}
+
+#define ___DO_LAZY 1
+#define ___DO_NOW 2
+
+static int _dl_parse(struct elf_resolve *tpnt, struct r_scope_elem *scope,
+ unsigned long rel_addr, unsigned long rel_size, int type)
+{
+ unsigned int i;
+ char *strtab;
+ ElfW(Sym) *symtab;
+ ELF_RELOC *rpnt;
+ int symtab_index;
+ int res = 0;
+
+ /* Now parse the relocation information */
+ rpnt = (ELF_RELOC *)(intptr_t) (rel_addr);
+ rel_size = rel_size / sizeof(ELF_RELOC);
+
+ symtab = (ElfW(Sym) *)(intptr_t) (tpnt->dynamic_info[DT_SYMTAB]);
+ strtab = (char *) (tpnt->dynamic_info[DT_STRTAB]);
+
+ for (i = 0; i < rel_size; i++, rpnt++) {
+
+ symtab_index = ELF_R_SYM(rpnt->r_info);
+
+ debug_sym(symtab,strtab,symtab_index);
+ debug_reloc(symtab,strtab,rpnt);
+
+ /* constant propagation subsumes the 'if' */
+ if (type == ___DO_LAZY)
+ res = _dl_do_lazy_reloc(tpnt, scope, rpnt);
+ else
+ res = _dl_do_reloc(tpnt, scope, rpnt, symtab, strtab);
+
+ if (res != 0)
+ break;
+ }
+
+ if (unlikely(res != 0)) {
+ if (res < 0) {
+ int reloc_type = ELF_R_TYPE(rpnt->r_info);
+#if defined __SUPPORT_LD_DEBUG__
+ _dl_dprintf(2, "can't handle reloc type %s\n ",
+ _dl_reltypes(reloc_type));
+#else
+ _dl_dprintf(2, "can't handle reloc type %x\n",
+ reloc_type);
+#endif
+ _dl_exit(-res);
+ } else {
+ _dl_dprintf(2, "can't resolve symbol\n");
+ /* Fall thru to return res */
+ }
+ }
+
+ return res;
+}
+
+void
+_dl_parse_lazy_relocation_information(struct dyn_elf *rpnt,
+ unsigned long rel_addr,
+ unsigned long rel_size)
+{
+ /* This func is called for processing .rela.plt of loaded module(s)
+ * The relo entries handled are JMP_SLOT type for fixing up .got slots
+ * for external function calls.
+ * This function doesn't resolve the slots: that is done lazily at
+ * runtime. The build linker (at least thats what happens for ARC) had
+ * pre-init the .got slots to point to PLT0. All that is done here is
+ * to fix them up to point to load value of PLT0 (as opposed to the
+ * build value).
+ * On ARC, the loadaddr of dyn exec is zero, thus elfaddr == loadaddr
+ * Thus there is no point in adding "0" to values and un-necessarily
+ * stir up the caches and TLB.
+ * For lsdo processing busybox binary, this skips over 380 relo entries
+ */
+ if (rpnt->dyn->loadaddr != 0)
+ _dl_parse(rpnt->dyn, NULL, rel_addr, rel_size, ___DO_LAZY);
+}
+
+int
+_dl_parse_relocation_information(struct dyn_elf *rpnt,
+ struct r_scope_elem *scope,
+ unsigned long rel_addr,
+ unsigned long rel_size)
+{
+ return _dl_parse(rpnt->dyn, scope, rel_addr, rel_size, ___DO_NOW);
+}