Find the dlopened file using address rather than file path.

This should fix the build bot.  It was failing because the
path which we pass to dlopen is not the path that gets mmaped.

Bug: 21854739
Change-Id: I0c28c74b62743f74f9ff3ae89e6f1beb0c1113ae

diff --git a/runtime/oat_file.cc b/runtime/oat_file.cc
index e426eb3..225fee0 100644 (file)
--- a/runtime/oat_file.cc
+++ b/runtime/oat_file.cc
@@ -281,23 +281,37 @@ bool OatFile::Dlopen(const std::string& elf_filename, uint8_t* requested_base,
   struct dl_iterate_context {
     static int callback(struct dl_phdr_info *info, size_t /* size */, void *data) {
       auto* context = reinterpret_cast<dl_iterate_context*>(data);
-      if (info->dlpi_name != nullptr && info->dlpi_name == context->so_name) {
+      // See whether this callback corresponds to the file which we have just loaded.
+      bool contains_begin = false;
+      for (int i = 0; i < info->dlpi_phnum; i++) {
+        if (info->dlpi_phdr[i].p_type == PT_LOAD) {
+          uint8_t* vaddr = reinterpret_cast<uint8_t*>(info->dlpi_addr +
+                                                      info->dlpi_phdr[i].p_vaddr);
+          size_t memsz = info->dlpi_phdr[i].p_memsz;
+          if (vaddr <= context->begin_ && context->begin_ < vaddr + memsz) {
+            contains_begin = true;
+            break;
+          }
+        }
+      }
+      // Add dummy mmaps for this file.
+      if (contains_begin) {
         for (int i = 0; i < info->dlpi_phnum; i++) {
           if (info->dlpi_phdr[i].p_type == PT_LOAD) {
-            auto vaddr = reinterpret_cast<uint8_t*>(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr);
-            MemMap::MapDummy(info->dlpi_name, vaddr, info->dlpi_phdr[i].p_memsz);
-            context->found = true;
+            uint8_t* vaddr = reinterpret_cast<uint8_t*>(info->dlpi_addr +
+                                                        info->dlpi_phdr[i].p_vaddr);
+            size_t memsz = info->dlpi_phdr[i].p_memsz;
+            MemMap::MapDummy(info->dlpi_name, vaddr, memsz);
           }
         }
+        return 1;  // Stop iteration and return 1 from dl_iterate_phdr.
       }
-      return 0;
+      return 0;  // Continue iteration and return 0 from dl_iterate_phdr when finished.
     }
-    std::string so_name;
-    bool found;
-  } context = { elf_filename, false };
-  dl_iterate_phdr(dl_iterate_context::callback, &context);
+    const uint8_t* begin_;
+  } context = { begin_ };
 
-  if (!context.found) {
+  if (dl_iterate_phdr(dl_iterate_context::callback, &context) == 0) {
     PrintFileToLog("/proc/self/maps", LogSeverity::WARNING);
     LOG(ERROR) << "File " << elf_filename << " loaded with dlopen but can not find its mmaps.";
   }