am aea393c0: Merge "Remove has_DT_SYMBOLIC flag"

* commit 'aea393c096460669647acbe803617affc5bc0697':
  Remove has_DT_SYMBOLIC flag

linker/dlfcn.cpp

@@ -244,7 +244,6 @@ soinfo* get_libdl_info() {
     __libdl_info.nchain = sizeof(g_libdl_chains)/sizeof(unsigned);
     __libdl_info.bucket = g_libdl_buckets;
     __libdl_info.chain = g_libdl_chains;
-    __libdl_info.has_DT_SYMBOLIC = true;
     __libdl_info.ref_count = 1;
   }
 

linker/linker.cpp

@@ -486,50 +486,22 @@ static ElfW(Sym)* soinfo_do_lookup(soinfo* si, const char* name, soinfo** lsi) {
   ElfW(Sym)* s = nullptr;
 
   if (somain != nullptr) {
-    /*
-     * Local scope is executable scope. Just start looking into it right away
-     * for the shortcut.
-     */
-
-    if (si == somain) {
-      s = soinfo_elf_lookup(si, elf_hash, name);
-      if (s != nullptr) {
-        *lsi = si;
-        goto done;
-      }
-
-      /* Next, look for it in the preloads list */
-      for (int i = 0; g_ld_preloads[i] != NULL; i++) {
-        s = soinfo_elf_lookup(g_ld_preloads[i], elf_hash, name);
-        if (s != NULL) {
-          *lsi = g_ld_preloads[i];
-          goto done;
-        }
-      }
-    } else {
-      /* Order of symbol lookup is controlled by DT_SYMBOLIC flag */
-
-      /*
-       * If this object was built with symbolic relocations disabled, the
-       * first place to look to resolve external references is the main
-       * executable.
-       */
-
-      if (!si->has_DT_SYMBOLIC) {
     DEBUG("%s: looking up %s in executable %s",
           si->name, name, somain->name);
+
+    // 1. Look for it in the main executable
     s = soinfo_elf_lookup(somain, elf_hash, name);
     if (s != nullptr) {
       *lsi = somain;
-          goto done;
     }
 
-        /* Next, look for it in the preloads list */
+    // 2. Look for it in the ld_preloads
+    if (s == nullptr) {
       for (int i = 0; g_ld_preloads[i] != NULL; i++) {
         s = soinfo_elf_lookup(g_ld_preloads[i], elf_hash, name);
-          if (s != NULL) {
+        if (s != nullptr) {
           *lsi = g_ld_preloads[i];
-            goto done;
+          break;
         }
       }
     }
@@ -544,38 +516,15 @@ static ElfW(Sym)* soinfo_do_lookup(soinfo* si, const char* name, soinfo** lsi) {
      * and some the first non-weak definition.   This is system dependent.
      * Here we return the first definition found for simplicity.  */
 
+    if (s == nullptr) {
       s = soinfo_elf_lookup(si, elf_hash, name);
       if (s != nullptr) {
         *lsi = si;
-        goto done;
-      }
-
-      /*
-       * If this object was built with -Bsymbolic and symbol is not found
-       * in the local scope, try to find the symbol in the main executable.
-       */
-
-      if (si->has_DT_SYMBOLIC) {
-        DEBUG("%s: looking up %s in executable %s after local scope",
-              si->name, name, somain->name);
-        s = soinfo_elf_lookup(somain, elf_hash, name);
-        if (s != nullptr) {
-          *lsi = somain;
-          goto done;
-        }
-
-        /* Next, look for it in the preloads list */
-        for (int i = 0; g_ld_preloads[i] != NULL; i++) {
-          s = soinfo_elf_lookup(g_ld_preloads[i], elf_hash, name);
-          if (s != NULL) {
-            *lsi = g_ld_preloads[i];
-            goto done;
-          }
-        }
       }
     }
   }
 
+  if (s == nullptr) {
     si->get_children().visit([&](soinfo* child) {
       DEBUG("%s: looking up %s in %s", si->name, name, child->name);
       s = soinfo_elf_lookup(child, elf_hash, name);
@@ -585,18 +534,17 @@ static ElfW(Sym)* soinfo_do_lookup(soinfo* si, const char* name, soinfo** lsi) {
       }
       return true;
     });
+  }
 
-done:
   if (s != nullptr) {
     TRACE_TYPE(LOOKUP, "si %s sym %s s->st_value = %p, "
                "found in %s, base = %p, load bias = %p",
                si->name, name, reinterpret_cast<void*>(s->st_value),
                (*lsi)->name, reinterpret_cast<void*>((*lsi)->base),
                reinterpret_cast<void*>((*lsi)->load_bias));
-    return s;
   }
 
-  return nullptr;
+  return s;
 }
 
 // Each size has it's own allocator.
@@ -2026,7 +1974,7 @@ bool soinfo::PrelinkImage() {
         break;
 #endif
       case DT_SYMBOLIC:
-        has_DT_SYMBOLIC = true;
+        // ignored
         break;
       case DT_NEEDED:
         ++needed_count;
@@ -2040,9 +1988,6 @@ bool soinfo::PrelinkImage() {
           has_text_relocations = true;
 #endif
         }
-        if (d->d_un.d_val & DF_SYMBOLIC) {
-          has_DT_SYMBOLIC = true;
-        }
         break;
 #if defined(__mips__)
       case DT_STRSZ:
@@ -2076,8 +2021,10 @@ bool soinfo::PrelinkImage() {
 #endif
 
       default:
-        DEBUG("Unused DT entry: type %p arg %p",
+        if (!relocating_linker) {
+          DL_WARN("%s: unused DT entry: type %p arg %p", name,
               reinterpret_cast<void*>(d->d_tag), reinterpret_cast<void*>(d->d_un.d_val));
+        }
         break;
     }
   }

linker/linker.h

@@ -197,9 +197,7 @@ struct soinfo {
 #if !defined(__LP64__)
   bool has_text_relocations;
 #endif
-  // TODO: remove this flag, dynamic linker
-  // should not use it in any way.
-  bool has_DT_SYMBOLIC;
+  bool unused4; // DO NOT USE, maintained for compatibility
 
   soinfo(const char* name, const struct stat* file_stat, int rtld_flags);