Fail explicitly on length overflow.
Instead of aborting when FileMap::create detects an overflow, detect the
overflow directly and fail the call.
Bug: 156997193
Test: Ran unit tests, including new unit test that aborted before.
Change-Id: Ie49975b8949fd12bbde14346ec9bbb774ef88a51
Merged-In: Ie49975b8949fd12bbde14346ec9bbb774ef88a51
(cherry picked from commit 68604b9c29b5bd11e2e2dbb848d6b364bf627d21)
(cherry picked from commit 4d14303653247da3922242796ab6d63123fbd004)
diff --git a/libutils/FileMap.cpp b/libutils/FileMap.cpp
index 3c4d81c..2e19d66 100644
--- a/libutils/FileMap.cpp
+++ b/libutils/FileMap.cpp
@@ -190,6 +190,10 @@
adjust = offset % mPageSize;
adjOffset = offset - adjust;
adjLength = length + adjust;
+ 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;