temporary

main.cc

@@ -333,103 +333,144 @@ static void set_isec_offsets() {
 static void scan_rels(ArrayRef<ObjectFile *> files) {
   MyTimer t("scan_rels", before_copy_timer);
 
-  tbb::parallel_for_each(files, [&](ObjectFile *file) { file->scan_relocations(); });
+  tbb::parallel_for_each(files, [&](ObjectFile *file) {
+    for (InputSection *isec : file->sections)
+      if (isec)
+        isec->scan_relocations();
+  });
+
+  tbb::parallel_for_each(files, [&](ObjectFile *file) {
+    for (Symbol *sym : file->symbols) {
+      if (sym->file != file)
+        continue;
+
+      u8 rels = sym->rels.load(std::memory_order_relaxed);
+
+      if (rels & Symbol::HAS_GOT_REL) {
+        sym->got_idx = file->num_got++;
+        file->num_reldyn++;
+        sym->needs_dynsym = true;
+      }
+
+      if (rels & Symbol::HAS_PLT_REL) {
+        sym->plt_idx = file->num_plt++;
+        sym->needs_dynsym = true;
+
+        if (sym->got_idx == -1) {
+          sym->gotplt_idx = file->num_gotplt++;
+          sym->relplt_idx = file->num_relplt++;
+        }
+      }
+
+      if (rels & Symbol::HAS_GOTGD_REL) {
+        sym->gotgd_idx = file->num_got;
+        file->num_got += 2;
+        file->num_reldyn += 2;
+        sym->needs_dynsym = true;
+      }
+
+      if (rels & Symbol::HAS_GOTLD_REL) {
+        sym->gotgd_idx = file->num_got++;
+        file->num_reldyn++;
+        sym->needs_dynsym = true;
+      }
+
+      if (rels & Symbol::HAS_GOTTP_REL)
+       sym->gottp_idx = file->num_got++;
+
+      if (sym->needs_dynsym)
+        file->num_dynsym++;
+    }
+  });
 
   for (ObjectFile *file : files) {
+
     file->got_offset = out::got->shdr.sh_size;
     out::got->shdr.sh_size += file->num_got * GOT_SIZE;
 
     file->gotplt_offset = out::gotplt->shdr.sh_size;
-    out::gotplt->shdr.sh_size += file->num_plt * GOT_SIZE;
+    out::gotplt->shdr.sh_size += file->num_gotplt * GOT_SIZE;
 
     file->plt_offset = out::plt->shdr.sh_size;
     out::plt->shdr.sh_size += file->num_plt * PLT_SIZE;
 
     file->relplt_offset = out::relplt->shdr.sh_size;
-    out::relplt->shdr.sh_size += file->num_plt * sizeof(ELF64LE::Rela);
+    out::relplt->shdr.sh_size += file->num_relplt * sizeof(ELF64LE::Rela);
 
-    if (out::dynsym) {
+    file->reldyn_offset = out::reldyn->shdr.sh_size;
-      file->dynsym_offset = out::dynsym->shdr.sh_size;
+    out::reldyn->shdr.sh_size += file->num_reldyn * sizeof(ELF64LE::Rela);
-      out::dynsym->shdr.sh_size += file->num_dynsym * sizeof(ELF64LE::Sym);
-    }
 
-    if (out::dynstr) {
+    file->dynsym_offset = out::dynsym->shdr.sh_size;
-      file->dynstr_offset = out::dynstr->shdr.sh_size;
+    out::dynsym->shdr.sh_size += file->num_dynsym * sizeof(ELF64LE::Sym);
-      out::dynstr->shdr.sh_size += file->dynstr_size;
+
-    }
+    file->dynstr_offset = out::dynstr->shdr.sh_size;
+    out::dynstr->shdr.sh_size += file->dynstr_size;
   }
 }
 
-static void assign_got_offsets(ArrayRef<ObjectFile *> files) {
+static void write_dynamic_rel(u8 *buf, u8 type, u64 offset, u64 addend) {
-  MyTimer t("assign_got_offsets", before_copy_timer);
+  ELF64LE::Rela *rel = (ELF64LE::Rela *)buf;
-
+  memset(rel, 0, sizeof(*rel));
-  tbb::parallel_for_each(files, [&](ObjectFile *file) {
+  rel->setType(type, false);
-    u32 got_offset = file->got_offset;
+  rel->r_offset = offset;
-    u32 gotplt_offset = file->gotplt_offset;
+  rel->r_addend = addend;
-    u32 plt_offset = file->plt_offset;
-    u32 relplt_offset = file->relplt_offset;
-    u32 dynsym_offset = file->dynsym_offset;
-
-    for (Symbol *sym : file->symbols) {
-      if (sym->file != file)
-        continue;
-
-      u8 flags = sym->flags.load(std::memory_order_relaxed);
-
-      if (flags & Symbol::NEEDS_GOT) {
-        sym->got_offset = got_offset;
-        got_offset += GOT_SIZE;
-      }
-
-      if (flags & Symbol::NEEDS_GOTTP) {
-        sym->gottp_offset = got_offset;
-        got_offset += GOT_SIZE;
-      }
-
-      if (flags & Symbol::NEEDS_PLT) {
-        sym->gotplt_offset = gotplt_offset;
-        gotplt_offset += GOT_SIZE;
-
-        sym->plt_offset = plt_offset;
-        plt_offset += PLT_SIZE;
-
-        sym->relplt_offset = relplt_offset;
-        relplt_offset += sizeof(ELF64LE::Rela);
-      }
-
-      if (flags & Symbol::NEEDS_DYNSYM) {
-        sym->dynsym_offset = dynsym_offset;
-        dynsym_offset += sizeof(ELF64LE::Sym);
-      }
-    }
-  });
 }
 
 static void write_got(u8 *buf, ArrayRef<ObjectFile *> files) {
   MyTimer t("write_synthetic", copy_timer);
 
-  u8 *got_buf = buf + out::got->shdr.sh_offset;
-  u8 *gotplt_buf = buf + out::gotplt->shdr.sh_offset;
-  u8 *relplt_buf = buf + out::relplt->shdr.sh_offset;
-  u8 *dynsym_buf = buf + out::dynsym->shdr.sh_offset;
-  u8 *dynstr_buf = buf + out::dynstr->shdr.sh_offset;
-
   tbb::parallel_for_each(files, [&](ObjectFile *file) {
-    u32 dynstr_offset = file->dynstr_offset;
+    u8 *got_buf = buf + out::got->shdr.sh_offset + file->got_offset;
+    u8 *gotplt_buf = buf + out::gotplt->shdr.sh_offset + file->gotplt_offset;
+    u8 *plt_buf = buf + out::plt->shdr.sh_offset + file->plt_offset;
+    u8 *relplt_buf = buf + out::relplt->shdr.sh_offset + file->relplt_offset;
+    u8 *reldyn_buf = buf + out::reldyn->shdr.sh_offset + file->reldyn_offset;
+    u8 *dynsym_buf = buf + out::dynsym->shdr.sh_offset + file->dynsym_offset;
+    u8 *dynstr_buf = buf + out::dynstr->shdr.sh_offset + file->dynstr_offset;
+
+    int reldyn_idx = 0;
 
     for (Symbol *sym : file->symbols) {
       if (sym->file != file)
         continue;
 
-      u8 flags = sym->flags.load(std::memory_order_relaxed);
+      if (got_idx != -1) {
+        *(u64 *)(got_buf + sym->got_idx * GOT_SIZE) = sym->get_addr();
+        write_dynamic_rel(reldyn_buf + reldyn_idx++ * sizeof(ELF64LE::Rela),
+                          R_X86_64_GLOB_DAT, sym->get_got_addr(), 0);
+      }
 
-      if (flags & Symbol::NEEDS_GOT)
+      if (sym->gottp_idx != -1)
+        *(u64 *)(got_buf + sym->gottp_idx * GOT_SIZE) = sym->get_addr() - out::tls_end;
+
+      if (sym->gotgd_idx != -1)
+        error("unimplemented");
+
+      if (sym->gotld_idx != -1)
+        error("unimplemented");
+
+      if (sym->plt_idx != -1)
+        out::plt->write_entry(buf, sym);
+
+      if (sym->relplt_idx != -1) {
+        if (sym->type == STT_GNU_IFUNC)
+          write_dynamic_rel(relplt_buf + sym->relplt_idx * sizeof(ELF64LE::Rela),
+                            R_X86_64_IRELATIVE, sym->get_plt_addr(), 0);
+        else
+          write_dynamic_rel(relplt_buf + sym->relplt_idx * sizeof(ELF64LE::Rela),
+                            R_X86_64_JUMP_SLOT, sym->get_plt_addr(), 0);
+      }
+
+
+      if (rels & Symbol::NEEDS_GOT)
         *(u64 *)(got_buf + sym->got_offset) = sym->get_addr();
 
-      if (flags & Symbol::NEEDS_GOTTP)
+      if (rels & Symbol::NEEDS_GOTTP)
-        *(u64 *)(got_buf + sym->gottp_offset) = sym->get_addr() - out::tls_end;
 
-      if (flags & Symbol::NEEDS_PLT) {
+
+
+
+      if (rels & Symbol::NEEDS_PLT) {
         // Write a .plt entry
         u64 S = out::gotplt->shdr.sh_addr + sym->gotplt_offset;
         u64 P = out::plt->shdr.sh_addr + sym->plt_offset;
@@ -451,7 +492,7 @@ static void write_got(u8 *buf, ArrayRef<ObjectFile *> files) {
         }
       }
 
-      if (flags & Symbol::NEEDS_DYNSYM) {
+      if (rels & Symbol::NEEDS_DYNSYM) {
         // Write to .dynsym
         auto &esym = *(ELF64LE::Sym *)(dynsym_buf + sym->dynsym_offset);
         memset(&esym, 0, sizeof(esym));
@@ -1134,9 +1175,6 @@ int main(int argc, char **argv) {
   // Assign offsets to output sections
   u64 filesize = set_osec_offsets(chunks);
 
-  // Assign symbols to GOT offsets
-  assign_got_offsets(files);
-
   // Fix linker-synthesized symbol addresses.
   fix_synthetic_symbols(chunks);
 

mold.h

@@ -187,6 +187,12 @@ public:
   }
 
   inline u64 get_addr() const;
+  inline u64 get_got_addr() const;
+  inline u64 get_gotplt_addr() const;
+  inline u64 get_gottp_addr() const;
+  inline u64 get_gotgd_addr() const;
+  inline u64 get_gotld_addr() const;
+  inline u64 get_plt_addr() const;
 
   StringRef name;
   ObjectFile *file = nullptr;
@@ -194,12 +200,15 @@ public:
   StringPieceRef piece_ref;
 
   u64 value = 0;
-  u32 got_offset = 0;
+  u32 got_idx = -1;
-  u32 gotplt_offset = 0;
+  u32 gotplt_idx = -1;
-  u32 gottp_offset = 0;
+  u32 gottp_idx = -1;
-  u32 plt_offset = 0;
+  u32 gotgd_idx = -1;
-  u32 relplt_offset = 0;
+  u32 gotld_idx = -1;
-  u32 dynsym_offset = 0;
+  u32 plt_idx = -1;
+  u32 relplt_idx = -1;
+  u32 dynsym_offset = -1;
+  bool needs_dynsym = false;
 
   u32 shndx = 0;
 
@@ -528,6 +537,36 @@ inline u64 Symbol::get_addr() const {
   return value;
 }
 
+inline u64 Symbol::get_got_addr() const {
+  assert(got_idx != -1);
+  return out::got->shdr.sh_addr + sym->file->got_offset + got_idx * GOT_SIZE;
+}
+
+inline u64 Symbol::get_gotplt_addr() const {
+  assert(gotplt_idx != -1);
+  return out::gotplt->shdr.sh_addr + sym->file->gotplt_offset + gotplt_idx * GOT_SIZE;
+}
+
+inline u64 Symbol::get_gottp_addr() const {
+  assert(gottp_idx != -1);
+  return out::got->shdr.sh_addr + sym->file->got_offset + gottp_idx * GOT_SIZE;
+}
+
+inline u64 Symbol::get_gotgd_addr() const {
+  assert(gotgd_idx != -1);
+  return out::got->shdr.sh_addr + sym->file->got_offset + gotgd_idx * GOT_SIZE;
+}
+
+inline u64 Symbol::get_gotld_addr() const {
+  assert(gotld_idx != -1);
+  return out::got->shdr.sh_addr + sym->file->got_offset + gotld_idx * GOT_SIZE;
+}
+
+inline u64 Symbol::get_plt_addr() const {
+  assert(plt_idx != -1);
+  return out::plt->shdr.sh_addr + sym->file->plt_offset + plt_idx * PLT_SIZE;
+}
+
 inline u64 StringPiece::get_addr() const {
   MergeableSection *is = isec.load();
   return is->parent.shdr.sh_addr + is->offset + output_offset;
@@ -565,7 +604,6 @@ public:
   void eliminate_duplicate_comdat_groups();
   void assign_mergeable_string_offsets();
   void convert_common_symbols();
-  void scan_relocations();
   void compute_symtab();
 
   void write_local_symtab(u8 *buf, u64 symtab_off, u64 strtab_off);
@@ -591,15 +629,19 @@ public:
   u64 global_symtab_size = 0;
   u64 global_strtab_size = 0;
 
-  std::atomic_uint32_t num_got = ATOMIC_VAR_INIT(0);
+  u32 num_got = 0;
-  std::atomic_uint32_t num_plt = ATOMIC_VAR_INIT(0);
+  u32 num_gotplt = 0;
-  std::atomic_uint32_t num_dynsym = ATOMIC_VAR_INIT(0);
+  u32 num_plt = 0;
-  std::atomic_uint32_t dynstr_size = ATOMIC_VAR_INIT(0);
+  u32 num_relplt = 0;
+  u32 num_reldyn = 0;
+  u32 num_dynsym = 0;
+  u32 dynstr_size = 0;
 
   u32 got_offset = 0;
   u32 gotplt_offset = 0;
   u32 plt_offset = 0;
   u32 relplt_offset = 0;
+  u32 reldyn_offset = 0;
   u32 dynsym_offset = 0;
   u32 dynstr_offset = 0;
 

object_file.cc

@@ -473,12 +473,6 @@ void ObjectFile::convert_common_symbols() {
   }
 }
 
-void ObjectFile::scan_relocations() {
-  for (InputSection *isec : sections)
-    if (isec)
-      isec->scan_relocations();
-}
-
 void ObjectFile::compute_symtab() {
   for (int i = first_global; i < elf_syms.size(); i++) {
     const ELF64LE::Sym &esym = elf_syms[i];

output_chunks.cc

@@ -92,19 +92,28 @@ void PltSection::initialize(u8 *buf) {
 }
 
 void PltSection::write_entry(u8 *buf, Symbol *sym) {
-  const u8 data[] = {
+  if (sym->got_idx == -1) {
-    0xff, 0x25, 0, 0, 0, 0, // jmp   *foo@GOTPLT
+    const u8 data[] = {
-    0x68, 0,    0, 0, 0,    // push  $index_in_relplt
+      0xff, 0x25, 0, 0, 0, 0, // jmp   *foo@GOTPLT
-    0xe9, 0,    0, 0, 0,    // jmp   PLT[0]
+      0x68, 0,    0, 0, 0,    // push  $index_in_relplt
-  };
+      0xe9, 0,    0, 0, 0,    // jmp   PLT[0]
+    };
 
-  u64 entry_addr = shdr.sh_addr + sym->plt_offset;
+    u8 *base = buf + shdr.sh_offset + sym->plt_offset;
+    memcpy(base, data, sizeof(data));
+    *(u32 *)(base + 2) = sym->get_gotplt_addr() - sym->get_plt_addr() - 6;
+    *(u32 *)(base + 7) = sym->relplt_idx;
+    *(u32 *)(base + 12) = shdr.sh_addr - sym->get_plt_addr() - 16;
+  } else {
+    const u8 data[] = {
+      0xff, 0x25, 0,    0,    0,    0,                  // jmp   *foo@GOTPLT
+      0x66, 0x66, 0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nop
+    };
 
-  u8 *base = buf + shdr.sh_offset + sym->plt_offset;
+    u8 *base = buf + shdr.sh_offset + sym->plt_offset;
-  memcpy(base, data, sizeof(data));
+    memcpy(base, data, sizeof(data));
-  *(u32 *)(base + 2) = out::gotplt->shdr.sh_addr + sym->gotplt_offset - entry_addr - 6;
+    *(u32 *)(base + 2) = sym->get_got_addr() - sym->get_plt_addr() - 6;
-  *(u32 *)(base + 7) = sym->plt_offset / PLT_SIZE;
+  }
-  *(u32 *)(base + 12) = shdr.sh_addr - entry_addr - 16;
 }
 
 MergedSection *