Revert "Enable patchoat to write image relocation files"

This reverts commit fbe5f2f85244bf57707afb5520b2f9aa189d9d55.

Test is failing very often on the buildbots.

Bug: 66697305

Change-Id: I9be7471b1c988bdddeca732c39b9323125e4384d

4 files changed, 62 insertions, 546 deletions

diff --git a/patchoat/Android.bp b/patchoat/Android.bp
index 0e8e517cd4..0902823644 100644
--- a/patchoat/Android.bp
+++ b/patchoat/Android.bp
@@ -26,7 +26,6 @@ cc_defaults {
     },
     shared_libs: [
         "libbase",
-        "libcrypto", // For computing the digest of image file
     ],
 }
 
@@ -59,6 +58,5 @@ art_cc_test {
     ],
     shared_libs: [
         "libartd",
-        "libcrypto", // For computing the digest of image file
     ],
 }
diff --git a/patchoat/patchoat.cc b/patchoat/patchoat.cc
index 6c9cf864b3..eb648cba18 100644
--- a/patchoat/patchoat.cc
+++ b/patchoat/patchoat.cc
@@ -15,7 +15,6 @@
  */
 #include "patchoat.h"
 
-#include <openssl/sha.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/file.h>
@@ -43,7 +42,6 @@
 #include "gc/space/image_space.h"
 #include "image-inl.h"
 #include "intern_table.h"
-#include "leb128.h"
 #include "mirror/dex_cache.h"
 #include "mirror/executable.h"
 #include "mirror/method.h"
@@ -60,8 +58,6 @@
 
 namespace art {
 
-using android::base::StringPrintf;
-
 static const OatHeader* GetOatHeader(const ElfFile* elf_file) {
   uint64_t off = 0;
   if (!elf_file->GetSectionOffsetAndSize(".rodata", &off, nullptr)) {
@@ -124,134 +120,11 @@ static bool SymlinkFile(const std::string& input_filename, const std::string& ou
   return true;
 }
 
-bool PatchOat::GeneratePatch(
-    const MemMap& original,
-    const MemMap& relocated,
-    std::vector<uint8_t>* output,
-    std::string* error_msg) {
-  // FORMAT of the patch (aka image relocation) file:
-  // * SHA-256 digest (32 bytes) of original/unrelocated file (e.g., the one from /system)
-  // * List of monotonically increasing offsets (max value defined by uint32_t) at which relocations
-  //   occur.
-  //   Each element is represented as the delta from the previous offset in the list (first element
-  //   is a delta from 0). Each delta is encoded using unsigned LEB128: little-endian
-  //   variable-length 7 bits per byte encoding, where all bytes have the highest bit (0x80) set
-  //   except for the final byte which does not have that bit set. For example, 0x3f is offset 0x3f,
-  //   whereas 0xbf 0x05 is offset (0x3f & 0x7f) | (0x5 << 7) which is 0x2bf. Most deltas end up
-  //   being encoding using just one byte, achieving ~4x decrease in relocation file size compared
-  //   to the encoding where offsets are stored verbatim, as uint32_t.
-
-  size_t original_size = original.Size();
-  size_t relocated_size = relocated.Size();
-  if (original_size != relocated_size) {
-    *error_msg =
-        StringPrintf(
-            "Original and relocated image sizes differ: %zu vs %zu", original_size, relocated_size);
-    return false;
-  }
-  if ((original_size % 4) != 0) {
-    *error_msg = StringPrintf("Image size not multiple of 4: %zu", original_size);
-    return false;
-  }
-  if (original_size > UINT32_MAX) {
-    *error_msg = StringPrintf("Image too large: %zu" , original_size);
-    return false;
-  }
-
-  const ImageHeader& relocated_header =
-      *reinterpret_cast<const ImageHeader*>(relocated.Begin());
-  // Offsets are supposed to differ between original and relocated by this value
-  off_t expected_diff = relocated_header.GetPatchDelta();
-  if (expected_diff == 0) {
-    // Can't identify offsets which are supposed to differ due to relocation
-    *error_msg = "Relocation delta is 0";
-    return false;
-  }
-
-  // Output the SHA-256 digest of the original
-  output->resize(SHA256_DIGEST_LENGTH);
-  const uint8_t* original_bytes = original.Begin();
-  SHA256(original_bytes, original_size, output->data());
-
-  // Output the list of offsets at which the original and patched images differ
-  size_t last_diff_offset = 0;
-  size_t diff_offset_count = 0;
-  const uint8_t* relocated_bytes = relocated.Begin();
-  for (size_t offset = 0; offset < original_size; offset += 4) {
-    uint32_t original_value = *reinterpret_cast<const uint32_t*>(original_bytes + offset);
-    uint32_t relocated_value = *reinterpret_cast<const uint32_t*>(relocated_bytes + offset);
-    off_t diff = relocated_value - original_value;
-    if (diff == 0) {
-      continue;
-    } else if (diff != expected_diff) {
-      *error_msg =
-          StringPrintf(
-              "Unexpected diff at offset %zu. Expected: %jd, but was: %jd",
-              offset,
-              (intmax_t) expected_diff,
-              (intmax_t) diff);
-      return false;
-    }
-
-    uint32_t offset_diff = offset - last_diff_offset;
-    last_diff_offset = offset;
-    diff_offset_count++;
-
-    EncodeUnsignedLeb128(output, offset_diff);
-  }
-
-  if (diff_offset_count == 0) {
-    *error_msg = "Original and patched images are identical";
-    return false;
-  }
-
-  return true;
-}
-
-static bool WriteRelFile(
-    const MemMap& original,
-    const MemMap& relocated,
-    const std::string& rel_filename,
-    std::string* error_msg) {
-  std::vector<uint8_t> output;
-  if (!PatchOat::GeneratePatch(original, relocated, &output, error_msg)) {
-    return false;
-  }
-
-  std::unique_ptr<File> rel_file(OS::CreateEmptyFileWriteOnly(rel_filename.c_str()));
-  if (rel_file.get() == nullptr) {
-    *error_msg = StringPrintf("Failed to create/open output file %s", rel_filename.c_str());
-    return false;
-  }
-  if (!rel_file->WriteFully(output.data(), output.size())) {
-    *error_msg = StringPrintf("Failed to write to %s", rel_filename.c_str());
-    return false;
-  }
-  if (rel_file->FlushCloseOrErase() != 0) {
-    *error_msg = StringPrintf("Failed to flush and close %s", rel_filename.c_str());
-    return false;
-  }
-
-  return true;
-}
-
 bool PatchOat::Patch(const std::string& image_location,
                      off_t delta,
-                     const std::string& output_image_directory,
-                     const std::string& output_image_relocation_directory,
+                     const std::string& output_directory,
                      InstructionSet isa,
                      TimingLogger* timings) {
-  bool output_image = !output_image_directory.empty();
-  bool output_image_relocation = !output_image_relocation_directory.empty();
-  if ((!output_image) && (!output_image_relocation)) {
-    // Nothing to do
-    return true;
-  }
-  if ((output_image_relocation) && (delta == 0)) {
-    LOG(ERROR) << "Cannot output image relocation information when requested relocation delta is 0";
-    return false;
-  }
-
   CHECK(Runtime::Current() == nullptr);
   CHECK(!image_location.empty()) << "image file must have a filename.";
 
@@ -348,35 +221,32 @@ bool PatchOat::Patch(const std::string& image_location,
       return false;
     }
 
-    if (output_image) {
-      MaybePic is_oat_pic = IsOatPic(elf.get());
-      if (is_oat_pic >= ERROR_FIRST) {
-        // Error logged by IsOatPic
-        return false;
-      } else if (is_oat_pic == NOT_PIC) {
-        LOG(ERROR) << "patchoat cannot be used on non-PIC oat file: " << input_oat_file->GetPath();
+    MaybePic is_oat_pic = IsOatPic(elf.get());
+    if (is_oat_pic >= ERROR_FIRST) {
+      // Error logged by IsOatPic
+      return false;
+    } else if (is_oat_pic == NOT_PIC) {
+      LOG(ERROR) << "patchoat cannot be used on non-PIC oat file: " << input_oat_file->GetPath();
+      return false;
+    } else {
+      CHECK(is_oat_pic == PIC);
+
+      // Create a symlink.
+      std::string converted_image_filename = space->GetImageLocation();
+      std::replace(converted_image_filename.begin() + 1, converted_image_filename.end(), '/', '@');
+      std::string output_image_filename = output_directory +
+          (android::base::StartsWith(converted_image_filename, "/") ? "" : "/") +
+          converted_image_filename;
+      std::string output_vdex_filename =
+          ImageHeader::GetVdexLocationFromImageLocation(output_image_filename);
+      std::string output_oat_filename =
+          ImageHeader::GetOatLocationFromImageLocation(output_image_filename);
+
+      if (!ReplaceOatFileWithSymlink(input_oat_file->GetPath(),
+                                     output_oat_filename) ||
+          !SymlinkFile(input_vdex_filename, output_vdex_filename)) {
+        // Errors already logged by above call.
         return false;
-      } else {
-        CHECK(is_oat_pic == PIC);
-
-        // Create a symlink.
-        std::string converted_image_filename = space->GetImageLocation();
-        std::replace(
-            converted_image_filename.begin() + 1, converted_image_filename.end(), '/', '@');
-        std::string output_image_filename = output_image_directory +
-            (android::base::StartsWith(converted_image_filename, "/") ? "" : "/") +
-            converted_image_filename;
-        std::string output_vdex_filename =
-            ImageHeader::GetVdexLocationFromImageLocation(output_image_filename);
-        std::string output_oat_filename =
-            ImageHeader::GetOatLocationFromImageLocation(output_image_filename);
-
-        if (!ReplaceOatFileWithSymlink(input_oat_file->GetPath(),
-                                       output_oat_filename) ||
-            !SymlinkFile(input_vdex_filename, output_vdex_filename)) {
-          // Errors already logged by above call.
-          return false;
-        }
       }
     }
 
@@ -397,72 +267,28 @@ bool PatchOat::Patch(const std::string& image_location,
     }
   }
 
-  if (output_image) {
-    // Write the patched image spaces.
-    for (size_t i = 0; i < spaces.size(); ++i) {
-      gc::space::ImageSpace* space = spaces[i];
-
-      t.NewTiming("Writing image");
-      std::string converted_image_filename = space->GetImageLocation();
-      std::replace(converted_image_filename.begin() + 1, converted_image_filename.end(), '/', '@');
-      std::string output_image_filename = output_image_directory +
-          (android::base::StartsWith(converted_image_filename, "/") ? "" : "/") +
-          converted_image_filename;
-      std::unique_ptr<File> output_image_file(CreateOrOpen(output_image_filename.c_str()));
-      if (output_image_file.get() == nullptr) {
-        LOG(ERROR) << "Failed to open output image file at " << output_image_filename;
-        return false;
-      }
-
-      PatchOat& p = space_to_patchoat_map.find(space)->second;
+  // Write the patched image spaces.
+  for (size_t i = 0; i < spaces.size(); ++i) {
+    gc::space::ImageSpace* space = spaces[i];
 
-      bool success = p.WriteImage(output_image_file.get());
-      success = FinishFile(output_image_file.get(), success);
-      if (!success) {
-        return false;
-      }
+    t.NewTiming("Writing image");
+    std::string converted_image_filename = space->GetImageLocation();
+    std::replace(converted_image_filename.begin() + 1, converted_image_filename.end(), '/', '@');
+    std::string output_image_filename = output_directory +
+        (android::base::StartsWith(converted_image_filename, "/") ? "" : "/") +
+        converted_image_filename;
+    std::unique_ptr<File> output_image_file(CreateOrOpen(output_image_filename.c_str()));
+    if (output_image_file.get() == nullptr) {
+      LOG(ERROR) << "Failed to open output image file at " << output_image_filename;
+      return false;
     }
-  }
 
-  if (output_image_relocation) {
-    // Write the image relocation information for each space.
-    for (size_t i = 0; i < spaces.size(); ++i) {
-      gc::space::ImageSpace* space = spaces[i];
-
-      t.NewTiming("Writing image relocation");
-      std::string original_image_filename(space->GetImageLocation() + ".rel");
-      std::string image_relocation_filename =
-          output_image_relocation_directory
-              + (android::base::StartsWith(original_image_filename, "/") ? "" : "/")
-              + original_image_filename.substr(original_image_filename.find_last_of("/"));
-      File& input_image = *space_to_file_map.find(space)->second;
-      int64_t input_image_size = input_image.GetLength();
-      if (input_image_size < 0) {
-        LOG(ERROR) << "Error while getting input image size";
-        return false;
-      }
-      std::string error_msg;
-      std::unique_ptr<MemMap> original(MemMap::MapFile(input_image_size,
-                                                       PROT_READ,
-                                                       MAP_PRIVATE,
-                                                       input_image.Fd(),
-                                                       0,
-                                                       /*low_4gb*/false,
-                                                       input_image.GetPath().c_str(),
-                                                       &error_msg));
-      if (original.get() == nullptr) {
-        LOG(ERROR) << "Unable to map image file " << input_image.GetPath() << " : " << error_msg;
-        return false;
-      }
-
-      PatchOat& p = space_to_patchoat_map.find(space)->second;
-      const MemMap* relocated = p.image_;
+    PatchOat& p = space_to_patchoat_map.find(space)->second;
 
-      if (!WriteRelFile(*original, *relocated, image_relocation_filename, &error_msg)) {
-        LOG(ERROR) << "Failed to create image relocation file " << image_relocation_filename
-            << ": " << error_msg;
-        return false;
-      }
+    bool success = p.WriteImage(output_image_file.get());
+    success = FinishFile(output_image_file.get(), success);
+    if (!success) {
+      return false;
     }
   }
 
@@ -913,9 +739,6 @@ NO_RETURN static void Usage(const char *fmt, ...) {
   UsageError("  --output-image-file=<file.art>: Specifies the exact file to write the patched");
   UsageError("      image file to.");
   UsageError("");
-  UsageError("  --output-image-relocation-file=<file.art.rel>: Specifies the exact file to write");
-  UsageError("      the image relocation information to.");
-  UsageError("");
   UsageError("  --base-offset-delta=<delta>: Specify the amount to change the old base-offset by.");
   UsageError("      This value may be negative.");
   UsageError("");
@@ -931,13 +754,12 @@ static int patchoat_image(TimingLogger& timings,
                           InstructionSet isa,
                           const std::string& input_image_location,
                           const std::string& output_image_filename,
-                          const std::string& output_image_relocation_filename,
                           off_t base_delta,
                           bool base_delta_set,
                           bool debug) {
   CHECK(!input_image_location.empty());
-  if ((output_image_filename.empty()) && (output_image_relocation_filename.empty())) {
-    Usage("Image patching requires --output-image-file or --output-image-relocation-file");
+  if (output_image_filename.empty()) {
+    Usage("Image patching requires --output-image-file");
   }
 
   if (!base_delta_set) {
@@ -956,19 +778,9 @@ static int patchoat_image(TimingLogger& timings,
 
   TimingLogger::ScopedTiming pt("patch image and oat", &timings);
 
-  std::string output_image_directory =
+  std::string output_directory =
       output_image_filename.substr(0, output_image_filename.find_last_of('/'));
-  std::string output_image_relocation_directory =
-      output_image_relocation_filename.substr(
-          0, output_image_relocation_filename.find_last_of('/'));
-  bool ret =
-      PatchOat::Patch(
-          input_image_location,
-          base_delta,
-          output_image_directory,
-          output_image_relocation_directory,
-          isa,
-          &timings);
+  bool ret = PatchOat::Patch(input_image_location, base_delta, output_directory, isa, &timings);
 
   if (kIsDebugBuild) {
     LOG(INFO) << "Exiting with return ... " << ret;
@@ -999,7 +811,6 @@ static int patchoat(int argc, char **argv) {
   InstructionSet isa = InstructionSet::kNone;
   std::string input_image_location;
   std::string output_image_filename;
-  std::string output_image_relocation_filename;
   off_t base_delta = 0;
   bool base_delta_set = false;
   bool dump_timings = kIsDebugBuild;
@@ -1021,9 +832,6 @@ static int patchoat(int argc, char **argv) {
       input_image_location = option.substr(strlen("--input-image-location=")).data();
     } else if (option.starts_with("--output-image-file=")) {
       output_image_filename = option.substr(strlen("--output-image-file=")).data();
-    } else if (option.starts_with("--output-image-relocation-file=")) {
-      output_image_relocation_filename =
-          option.substr(strlen("--output-image-relocation-file=")).data();
     } else if (option.starts_with("--base-offset-delta=")) {
       const char* base_delta_str = option.substr(strlen("--base-offset-delta=")).data();
       base_delta_set = true;
@@ -1048,7 +856,6 @@ static int patchoat(int argc, char **argv) {
                            isa,
                            input_image_location,
                            output_image_filename,
-                           output_image_relocation_filename,
                            base_delta,
                            base_delta_set,
                            debug);
diff --git a/patchoat/patchoat.h b/patchoat/patchoat.h
index 1033a2e5e1..83516845d8 100644
--- a/patchoat/patchoat.h
+++ b/patchoat/patchoat.h
@@ -44,25 +44,12 @@ class Class;
 
 class PatchOat {
  public:
-  // Relocates the provided image by the specified offset. If output_image_directory is non-empty,
-  // outputs the relocated image into that directory. If output_image_relocation_directory is
-  // non-empty, outputs image relocation files (see GeneratePatch) into that directory.
   static bool Patch(const std::string& image_location,
                     off_t delta,
-                    const std::string& output_image_directory,
-                    const std::string& output_image_relocation_directory,
+                    const std::string& output_directory,
                     InstructionSet isa,
                     TimingLogger* timings);
 
-  // Generates a patch which can be used to efficiently relocate the original file or to check that
-  // a relocated file matches the original. The patch is generated from the difference of the
-  // |original| and the already |relocated| image, and written to |output| in the form of unsigned
-  // LEB128 for each relocation position.
-  static bool GeneratePatch(const MemMap& original,
-                            const MemMap& relocated,
-                            std::vector<uint8_t>* output,
-                            std::string* error_msg);
-
   ~PatchOat() {}
   PatchOat(PatchOat&&) = default;
 
diff --git a/patchoat/patchoat_test.cc b/patchoat/patchoat_test.cc
index fdd8fc4291..86e851c72b 100644
--- a/patchoat/patchoat_test.cc
+++ b/patchoat/patchoat_test.cc
@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 
-#include <openssl/sha.h>
 #include <dirent.h>
 #include <sys/types.h>
 
@@ -138,21 +137,6 @@ class PatchoatTest : public DexoptTest {
     return RunDex2OatOrPatchoat(argv, error_msg);
   }
 
-  bool GenerateBootImageRelFile(const std::string& input_image_location,
-                                const std::string& output_rel_filename,
-                                off_t base_offset_delta,
-                                std::string* error_msg) {
-    Runtime* const runtime = Runtime::Current();
-    std::vector<std::string> argv;
-    argv.push_back(runtime->GetPatchoatExecutable());
-    argv.push_back("--input-image-location=" + input_image_location);
-    argv.push_back("--output-image-relocation-file=" + output_rel_filename);
-    argv.push_back(StringPrintf("--base-offset-delta=0x%jx", (intmax_t) base_offset_delta));
-    argv.push_back(StringPrintf("--instruction-set=%s", GetInstructionSetString(kRuntimeISA)));
-
-    return RunDex2OatOrPatchoat(argv, error_msg);
-  }
-
   bool RunDex2OatOrPatchoat(const std::vector<std::string>& args, std::string* error_msg) {
     int link[2];
 
@@ -279,34 +263,6 @@ class PatchoatTest : public DexoptTest {
   }
 
   bool BinaryDiff(
-      const std::string& filename1,
-      const std::vector<uint8_t>& data1,
-      const std::string& filename2,
-      const std::vector<uint8_t>& data2,
-      std::string* error_msg) {
-    if (data1.size() != data1.size()) {
-      *error_msg =
-          StringPrintf(
-              "%s and %s are of different size: %zu vs %zu",
-              filename1.c_str(),
-              filename2.c_str(),
-              data1.size(),
-              data2.size());
-      return true;
-    }
-    size_t size = data1.size();
-    for (size_t i = 0; i < size; i++) {
-      if (data1[i] != data2[i]) {
-        *error_msg =
-            StringPrintf("%s and %s differ at offset %zu", filename1.c_str(), filename2.c_str(), i);
-        return true;
-      }
-    }
-
-    return false;
-  }
-
-  bool BinaryDiff(
       const std::string& filename1, const std::string& filename2, std::string* error_msg) {
     std::string read_error_msg;
     std::vector<uint8_t> image1;
@@ -319,127 +275,26 @@ class PatchoatTest : public DexoptTest {
       *error_msg = StringPrintf("Failed to read %s: %s", filename2.c_str(), read_error_msg.c_str());
       return true;
     }
-    return BinaryDiff(filename1, image1, filename2, image2, error_msg);
-  }
-
-  bool IsImageIdenticalToOriginalExceptForRelocation(
-      const std::string& relocated_filename,
-      const std::string& original_filename,
-      const std::string& rel_filename,
-      std::string* error_msg) {
-    *error_msg = "";
-    std::string read_error_msg;
-    std::vector<uint8_t> rel;
-    if (!ReadFully(rel_filename, &rel, &read_error_msg)) {
-      *error_msg =
-          StringPrintf("Failed to read %s: %s", rel_filename.c_str(), read_error_msg.c_str());
-      return false;
-    }
-    std::vector<uint8_t> relocated;
-    if (!ReadFully(relocated_filename, &relocated, &read_error_msg)) {
-      *error_msg =
-          StringPrintf("Failed to read %s: %s", relocated_filename.c_str(), read_error_msg.c_str());
-      return false;
-    }
-
-    size_t image_size = relocated.size();
-    if ((image_size % 4) != 0) {
-      *error_msg =
-          StringPrintf(
-              "Relocated image file %s size not multiple of 4: %zu",
-                  relocated_filename.c_str(), image_size);
-      return false;
-    }
-    if (image_size > UINT32_MAX) {
+    if (image1.size() != image2.size()) {
       *error_msg =
           StringPrintf(
-              "Relocated image file %s too large: %zu" , relocated_filename.c_str(), image_size);
-      return false;
+              "%s and %s are of different size: %zu vs %zu",
+              filename1.c_str(),
+              filename2.c_str(),
+              image1.size(),
+              image2.size());
+      return true;
     }
-
-    const ImageHeader& relocated_header = *reinterpret_cast<const ImageHeader*>(relocated.data());
-    off_t expected_diff = relocated_header.GetPatchDelta();
-
-    if (expected_diff != 0) {
-      // Relocated image is expected to differ from the original due to relocation.
-      // Unrelocate the image in memory to compensate.
-      uint8_t* image_start = relocated.data();
-      const uint8_t* rel_start = rel.data();
-      const uint8_t* rel_end = &rel[rel.size()];
-      if (rel.size() < SHA256_DIGEST_LENGTH) {
+    size_t size = image1.size();
+    for (size_t i = 0; i < size; i++) {
+      if (image1[i] != image2[i]) {
         *error_msg =
-            StringPrintf("Malformed image relocation file %s: too short", rel_filename.c_str());
-        return false;
-      }
-      const uint8_t* rel_ptr = &rel[SHA256_DIGEST_LENGTH];
-      // The remaining .rel file consists of offsets at which relocation should've occurred.
-      // For each offset, we "unrelocate" the image by subtracting the expected relocation
-      // diff value (as specified in the image header).
-      //
-      // Each offset is encoded as a delta/diff relative to the previous offset. With the
-      // very first offset being encoded relative to offset 0.
-      // Deltas are encoded using little-endian 7 bits per byte encoding, with all bytes except
-      // the last one having the highest bit set.
-      uint32_t offset = 0;
-      while (rel_ptr != rel_end) {
-        size_t offset_offset_in_rel = rel_ptr - rel_start;
-        uint32_t offset_delta = 0;
-        uint32_t shift = 0;
-        while (true) {
-          uint8_t b = *rel_ptr;
-          rel_ptr++;
-          offset_delta |= (b & 0x7f) << shift;
-          shift += 7;
-          if ((b & 0x80) == 0) {
-            // This is the last byte of the encoded offset delta
-            break;
-          }
-          // There are more bytes encoding this offset delta
-          if (rel_ptr == rel_end) {
-            *error_msg =
-                StringPrintf(
-                      "Malformed image relocation file %s: truncated delta at %zu",
-                          rel_filename.c_str(), offset_offset_in_rel);
-            return false;
-          }
-          if (shift > 22) {
-            *error_msg =
-                StringPrintf(
-                      "Malformed image relocation file %s: delta encoding too long at %zu",
-                      rel_filename.c_str(), offset_offset_in_rel);
-            return false;
-          }
-        }
-        offset += offset_delta;
-        if (offset >= image_size) {
-          *error_msg =
-              StringPrintf(
-                  "Malformed image relocation file %s: offset at %zu (%" PRIu32
-                      ") >= image size (%zu)",
-                  rel_filename.c_str(),
-                  offset_offset_in_rel,
-                  offset,
-                  image_size);
-          return false;
-        }
-        uint32_t *image_value = reinterpret_cast<uint32_t*>(image_start + offset);
-        *image_value -= expected_diff;
+            StringPrintf("%s and %s differ at offset %zu", filename1.c_str(), filename2.c_str(), i);
+        return true;
       }
     }
 
-    // Image in memory is now supposed to be identical to the original. Compare it to the original.
-    std::vector<uint8_t> original;
-    if (!ReadFully(original_filename, &original, &read_error_msg)) {
-      *error_msg =
-          StringPrintf("Failed to read %s: %s", original_filename.c_str(), read_error_msg.c_str());
-      return false;
-    }
-    if (BinaryDiff(relocated_filename, relocated, original_filename, original, error_msg)) {
-      return false;
-    }
-
-    // Relocated image is identical to the original, once relocations are taken into account
-    return true;
+    return false;
   }
 };
 
@@ -553,135 +408,4 @@ TEST_F(PatchoatTest, PatchoatRelocationSameAsDex2oatRelocation) {
 #endif
 }
 
-TEST_F(PatchoatTest, RelFileSufficientToUnpatch) {
-  // This test checks that a boot image relocated using patchoat can be unrelocated using the .rel
-  // file created by patchoat.
-
-  // Compile boot image into a random directory using dex2oat
-  ScratchFile dex2oat_orig_scratch;
-  dex2oat_orig_scratch.Unlink();
-  std::string dex2oat_orig_dir = dex2oat_orig_scratch.GetFilename();
-  ASSERT_EQ(0, mkdir(dex2oat_orig_dir.c_str(), 0700));
-  const uint32_t orig_base_addr = 0x60000000;
-  std::vector<std::string> dex2oat_extra_args;
-  std::string error_msg;
-  if (!CompileBootImageToDir(dex2oat_orig_dir, dex2oat_extra_args, orig_base_addr, &error_msg)) {
-    FAIL() << "CompileBootImage1 failed: " << error_msg;
-  }
-
-  // Generate image relocation file for the original boot image
-  ScratchFile rel_scratch;
-  rel_scratch.Unlink();
-  std::string rel_dir = rel_scratch.GetFilename();
-  ASSERT_EQ(0, mkdir(rel_dir.c_str(), 0700));
-  std::string dex2oat_orig_with_arch_dir =
-      dex2oat_orig_dir + "/" + GetInstructionSetString(kRuntimeISA);
-  // The arch-including symlink is needed by patchoat
-  ASSERT_EQ(0, symlink(dex2oat_orig_dir.c_str(), dex2oat_orig_with_arch_dir.c_str()));
-  off_t base_addr_delta = 0x100000;
-  if (!GenerateBootImageRelFile(
-      dex2oat_orig_dir + "/boot.art",
-      rel_dir + "/boot.art.rel",
-      base_addr_delta,
-      &error_msg)) {
-    FAIL() << "RelocateBootImage failed: " << error_msg;
-  }
-
-  // Relocate the original boot image using patchoat
-  ScratchFile relocated_scratch;
-  relocated_scratch.Unlink();
-  std::string relocated_dir = relocated_scratch.GetFilename();
-  ASSERT_EQ(0, mkdir(relocated_dir.c_str(), 0700));
-  // Use a different relocation delta from the one used when generating .rel files above. This is
-  // to make sure .rel files are not specific to a particular relocation delta.
-  base_addr_delta -= 0x10000;
-  if (!RelocateBootImage(
-      dex2oat_orig_dir + "/boot.art",
-      relocated_dir + "/boot.art",
-      base_addr_delta,
-      &error_msg)) {
-    FAIL() << "RelocateBootImage failed: " << error_msg;
-  }
-
-  // Assert that patchoat created the same set of .art and .art.rel files
-  std::vector<std::string> rel_basenames;
-  std::vector<std::string> relocated_image_basenames;
-  if (!ListDirFilesEndingWith(rel_dir, "", &rel_basenames, &error_msg)) {
-    FAIL() << "Failed to list *.art.rel files in " << rel_dir << ": " << error_msg;
-  }
-  if (!ListDirFilesEndingWith(relocated_dir, ".art", &relocated_image_basenames, &error_msg)) {
-    FAIL() << "Failed to list *.art files in " << relocated_dir << ": " << error_msg;
-  }
-  std::sort(rel_basenames.begin(), rel_basenames.end());
-  std::sort(relocated_image_basenames.begin(), relocated_image_basenames.end());
-
-  // .art and .art.rel file names output by patchoat look like
-  // tmp@art-data-<random>-<random>@boot*.art, encoding the name of the directory in their name.
-  // To compare these with each other, we retain only the part of the file name after the last @,
-  // and we also drop the extension.
-  std::vector<std::string> rel_shortened_basenames(rel_basenames.size());
-  std::vector<std::string> relocated_image_shortened_basenames(relocated_image_basenames.size());
-  for (size_t i = 0; i < rel_basenames.size(); i++) {
-    rel_shortened_basenames[i] = rel_basenames[i].substr(rel_basenames[i].find_last_of("@") + 1);
-    rel_shortened_basenames[i] =
-        rel_shortened_basenames[i].substr(0, rel_shortened_basenames[i].find("."));
-  }
-  for (size_t i = 0; i < relocated_image_basenames.size(); i++) {
-    relocated_image_shortened_basenames[i] =
-        relocated_image_basenames[i].substr(relocated_image_basenames[i].find_last_of("@") + 1);
-    relocated_image_shortened_basenames[i] =
-        relocated_image_shortened_basenames[i].substr(
-            0, relocated_image_shortened_basenames[i].find("."));
-  }
-  ASSERT_EQ(rel_shortened_basenames, relocated_image_shortened_basenames);
-
-  // For each image file, assert that unrelocating the image produces its original version
-  for (size_t i = 0; i < relocated_image_basenames.size(); i++) {
-    const std::string& original_image_filename =
-        dex2oat_orig_dir + "/" + relocated_image_shortened_basenames[i] + ".art";
-    const std::string& relocated_image_filename =
-        relocated_dir + "/" + relocated_image_basenames[i];
-    const std::string& rel_filename = rel_dir + "/" + rel_basenames[i];
-
-    // Assert that relocated image differs from the original
-    if (!BinaryDiff(original_image_filename, relocated_image_filename, &error_msg)) {
-      FAIL() << "Relocated image " << relocated_image_filename
-          << " identical to the original image " << original_image_filename;
-    }
-
-    // Assert that relocated image is identical to the original except for relocations described in
-    // the .rel file
-    if (!IsImageIdenticalToOriginalExceptForRelocation(
-        relocated_image_filename, original_image_filename, rel_filename, &error_msg)) {
-      FAIL() << "Unrelocating " << relocated_image_filename << " using " << rel_filename
-          << " did not produce the same output as " << original_image_filename << ": " << error_msg;
-    }
-
-    // Assert that the digest of original image in .rel file is as expected
-    std::vector<uint8_t> original;
-    if (!ReadFully(original_image_filename, &original, &error_msg)) {
-      FAIL() << "Failed to read original image " << original_image_filename;
-    }
-    std::vector<uint8_t> rel;
-    if (!ReadFully(rel_filename, &rel, &error_msg)) {
-      FAIL() << "Failed to read image relocation file " << rel_filename;
-    }
-    uint8_t original_image_digest[SHA256_DIGEST_LENGTH];
-    SHA256(original.data(), original.size(), original_image_digest);
-    const uint8_t* original_image_digest_in_rel_file = rel.data();
-    if (memcmp(original_image_digest_in_rel_file, original_image_digest, SHA256_DIGEST_LENGTH)) {
-      FAIL() << "Digest of original image in " << rel_filename << " does not match the original"
-          " image " << original_image_filename;
-    }
-  }
-
-  ClearDirectory(dex2oat_orig_dir.c_str(), /*recursive*/ true);
-  ClearDirectory(rel_dir.c_str(), /*recursive*/ true);
-  ClearDirectory(relocated_dir.c_str(), /*recursive*/ true);
-
-  rmdir(dex2oat_orig_dir.c_str());
-  rmdir(rel_dir.c_str());
-  rmdir(relocated_dir.c_str());
-}
-
 }  // namespace art