From de38b1a356add7b6cf863fe1b8d707525aca59cd Mon Sep 17 00:00:00 2001
From: Christopher Ferris <cferris@google.com>
Date: Wed, 6 May 2020 13:48:32 -0700
Subject: [PATCH] Change call to mmap64.

The code was using an off64_t but calling mmap. This caused the code
to abort on 32 bit.

Add a unit test that would abort on the previous version.

Bug: 155662887

Test: New unit test passes.
Change-Id: I7a6efbc0d4227403c3d08a08deea56f239382157
Merged-In: I7a6efbc0d4227403c3d08a08deea56f239382157
(cherry picked from commit 7b9f35c9de53352f915c5b5e8eb39dab09356c19)
---
 libutils/FileMap.cpp      |  2 +-
 libutils/FileMap_test.cpp | 20 ++++++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/libutils/FileMap.cpp b/libutils/FileMap.cpp
index 1202c156d..1d899ab7f 100644
--- a/libutils/FileMap.cpp
+++ b/libutils/FileMap.cpp
@@ -195,7 +195,7 @@ bool FileMap::create(const char* origFileName, int fd, off64_t offset, size_t le
     int prot = PROT_READ;
     if (!readOnly) prot |= PROT_WRITE;
 
-    void* ptr = mmap(nullptr, adjLength, prot, flags, fd, adjOffset);
+    void* ptr = mmap64(nullptr, adjLength, prot, flags, fd, adjOffset);
     if (ptr == MAP_FAILED) {
         if (errno == EINVAL && length == 0) {
             ptr = nullptr;
diff --git a/libutils/FileMap_test.cpp b/libutils/FileMap_test.cpp
index 576d89bbe..9f7ce85ca 100644
--- a/libutils/FileMap_test.cpp
+++ b/libutils/FileMap_test.cpp
@@ -32,3 +32,23 @@ TEST(FileMap, zero_length_mapping) {
     ASSERT_EQ(0u, m.getDataLength());
     ASSERT_EQ(4096, m.getDataOffset());
 }
+
+TEST(FileMap, large_offset) {
+    // Make sure that an offset > INT32_MAX will not fail the create
+    // function. See http://b/155662887.
+    TemporaryFile tf;
+    ASSERT_TRUE(tf.fd != -1);
+
+    off64_t offset = INT32_MAX + 1024LL;
+
+    // Make the temporary file large enough to pass the mmap.
+    ASSERT_EQ(offset, lseek64(tf.fd, offset, SEEK_SET));
+    char value = 0;
+    ASSERT_EQ(1, write(tf.fd, &value, 1));
+
+    android::FileMap m;
+    ASSERT_TRUE(m.create("test", tf.fd, offset, 0, true));
+    ASSERT_STREQ("test", m.getFileName());
+    ASSERT_EQ(0u, m.getDataLength());
+    ASSERT_EQ(offset, m.getDataOffset());
+}