Refactoring: move mips reloc to separate method
Change-Id: I712614853e3f0e515f5c2bdd8f0aaa5feeae8e55
diff --git a/linker/linker_mips.cpp b/linker/linker_mips.cpp
new file mode 100644
index 0000000..eb2ae84
--- /dev/null
+++ b/linker/linker_mips.cpp
@@ -0,0 +1,143 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "linker.h"
+#include "linker_debug.h"
+#include "linker_relocs.h"
+
+template<>
+bool soinfo::relocate(ElfW(Rel)* rel, unsigned count, const soinfo_list_t& global_group, const soinfo_list_t& local_group) {
+ for (size_t idx = 0; idx < count; ++idx, ++rel) {
+ ElfW(Word) type = ELFW(R_TYPE)(rel->r_info);
+ ElfW(Word) sym = ELFW(R_SYM)(rel->r_info);
+
+ ElfW(Addr) reloc = static_cast<ElfW(Addr)>(rel->r_offset + load_bias);
+ ElfW(Addr) sym_addr = 0;
+ const char* sym_name = nullptr;
+
+ DEBUG("Processing '%s' relocation at index %zd", this->name, idx);
+ if (type == R_GENERIC_NONE) {
+ continue;
+ }
+
+ ElfW(Sym)* s = nullptr;
+ soinfo* lsi = nullptr;
+
+ if (sym != 0) {
+ sym_name = get_string(symtab_[sym].st_name);
+ s = soinfo_do_lookup(this, sym_name, &lsi, global_group,local_group);
+ if (s == nullptr) {
+ // mips does not support relocation with weak-undefined symbols
+ DL_ERR("cannot locate symbol \"%s\" referenced by \"%s\"...", sym_name, name);
+ return false;
+ } else {
+ // We got a definition.
+ sym_addr = lsi->resolve_symbol_address(s);
+ }
+ count_relocation(kRelocSymbol);
+ }
+
+ switch (type) {
+ case R_MIPS_REL32:
+#if defined(__LP64__)
+ // MIPS Elf64_Rel entries contain compound relocations
+ // We only handle the R_MIPS_NONE|R_MIPS_64|R_MIPS_REL32 case
+ if (ELF64_R_TYPE2(rel->r_info) != R_MIPS_64 ||
+ ELF64_R_TYPE3(rel->r_info) != R_MIPS_NONE) {
+ DL_ERR("Unexpected compound relocation type:%d type2:%d type3:%d @ %p (%zu)",
+ type, (unsigned)ELF64_R_TYPE2(rel->r_info),
+ (unsigned)ELF64_R_TYPE3(rel->r_info), rel, idx);
+ return false;
+ }
+#endif
+ count_relocation(s == nullptr ? kRelocAbsolute : kRelocRelative);
+ MARK(rel->r_offset);
+ TRACE_TYPE(RELO, "RELO REL32 %08zx <- %08zx %s", static_cast<size_t>(reloc),
+ static_cast<size_t>(sym_addr), sym_name ? sym_name : "*SECTIONHDR*");
+ if (s != nullptr) {
+ *reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr;
+ } else {
+ *reinterpret_cast<ElfW(Addr)*>(reloc) += base;
+ }
+ break;
+ default:
+ DL_ERR("unknown reloc type %d @ %p (%zu)", type, rel, idx);
+ return false;
+ }
+ }
+ return true;
+}
+
+bool soinfo::mips_relocate_got(const soinfo_list_t& global_group, const soinfo_list_t& local_group) {
+ ElfW(Addr)** got = plt_got_;
+ if (got == nullptr) {
+ return true;
+ }
+
+ // got[0] is the address of the lazy resolver function.
+ // got[1] may be used for a GNU extension.
+ // Set it to a recognizable address in case someone calls it (should be _rtld_bind_start).
+ // FIXME: maybe this should be in a separate routine?
+ if ((flags_ & FLAG_LINKER) == 0) {
+ size_t g = 0;
+ got[g++] = reinterpret_cast<ElfW(Addr)*>(0xdeadbeef);
+ if (reinterpret_cast<intptr_t>(got[g]) < 0) {
+ got[g++] = reinterpret_cast<ElfW(Addr)*>(0xdeadfeed);
+ }
+ // Relocate the local GOT entries.
+ for (; g < mips_local_gotno_; g++) {
+ got[g] = reinterpret_cast<ElfW(Addr)*>(reinterpret_cast<uintptr_t>(got[g]) + load_bias);
+ }
+ }
+
+ // Now for the global GOT entries...
+ ElfW(Sym)* sym = symtab_ + mips_gotsym_;
+ got = plt_got_ + mips_local_gotno_;
+ for (size_t g = mips_gotsym_; g < mips_symtabno_; g++, sym++, got++) {
+ // This is an undefined reference... try to locate it.
+ const char* sym_name = get_string(sym->st_name);
+ soinfo* lsi = nullptr;
+ ElfW(Sym)* s = soinfo_do_lookup(this, sym_name, &lsi, global_group, local_group);
+ if (s == nullptr) {
+ // We only allow an undefined symbol if this is a weak reference.
+ s = &symtab_[g];
+ if (ELF_ST_BIND(s->st_info) != STB_WEAK) {
+ DL_ERR("cannot locate \"%s\"...", sym_name);
+ return false;
+ }
+ *got = 0;
+ } else {
+ // FIXME: is this sufficient?
+ // For reference see NetBSD link loader
+ // http://cvsweb.netbsd.org/bsdweb.cgi/src/libexec/ld.elf_so/arch/mips/mips_reloc.c?rev=1.53&content-type=text/x-cvsweb-markup
+ *got = reinterpret_cast<ElfW(Addr)*>(lsi->resolve_symbol_address(s));
+ }
+ }
+ return true;
+}
+