From: David Srbecky <dsrbecky@google.com>
Date: Wed, 17 Jun 2015 01:11:07 +0000 (+0100)
Subject: Find the dlopened file using address rather than file path.
X-Git-Tag: android-x86-7.1-r1~889^2~986^2
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=aa03870a9d3fe29fe89bd313c51a9cfb69edc775;p=android-x86%2Fart.git

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 e426eb310..225fee0a6 100644
--- 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.";
   }