commit f823839eaac3dceaa728a0e4e956df213faca9f8
author Elliott Hughes <enh@google.com> Mon Aug 17 12:37:25 2020 -0700
committer Anis Assi <anisassi@google.com> Thu Sep 10 13:50:20 2020 -0700
tree 342a84b24ecc63ff74aa0d6b4a70ac07d6892892
parent c30ee682ce3d681bb240b87fa13ebfb6f2933045

FileMap::create: remove duplicate addition.

The previous change was intended to detect the overflow, but
accidentally retained the existing addition, so we'd abort before
getting to the explicit check.

Also reformat slightly to better match the current code in qt-dev and
beyond, to reduce merge conflicts.

Bug: 156997193
Test: treehugger
Change-Id: I73a3a4e75f0aad00888e8f2b49a07b7e8b4eda05
Merged-In: I73a3a4e75f0aad00888e8f2b49a07b7e8b4eda05
(cherry picked from commit 54794ac613d50bf4072174476f60527e2b0b4cdf)

libutils/FileMap.cpp

diff --git a/libutils/FileMap.cpp b/libutils/FileMap.cpp
index b9f411e..45ca853 100644
--- a/libutils/FileMap.cpp
+++ b/libutils/FileMap.cpp
@@ -160,12 +160,6 @@
         return false;
     }
 #else // !defined(__MINGW32__)
-    int     prot, flags, adjust;
-    off64_t adjOffset;
-    size_t  adjLength;
-
-    void* ptr;
-
     assert(fd >= 0);
     assert(offset >= 0);
     assert(length > 0);
@@ -179,20 +173,19 @@
         }
     }
 
-    adjust = offset % mPageSize;
-    adjOffset = offset - adjust;
-    adjLength = length + adjust;
+    int adjust = offset % mPageSize;
+    off64_t adjOffset = offset - adjust;
+    size_t adjLength;
     if (__builtin_add_overflow(length, adjust, &adjLength)) {
         ALOGE("adjusted length overflow: length %zu adjust %d", length, adjust);
         return false;
     }
 
-    flags = MAP_SHARED;
-    prot = PROT_READ;
-    if (!readOnly)
-        prot |= PROT_WRITE;
+    int flags = MAP_SHARED;
+    int prot = PROT_READ;
+    if (!readOnly) prot |= PROT_WRITE;
 
-    ptr = mmap(NULL, adjLength, prot, flags, fd, adjOffset);
+    void* ptr = mmap(nullptr, adjLength, prot, flags, fd, adjOffset);
     if (ptr == MAP_FAILED) {
         ALOGE("mmap(%lld,%zu) failed: %s\n",
             (long long)adjOffset, adjLength, strerror(errno));