Josh Rosen f340b6b306 [SPARK-22997] Add additional defenses against use of freed MemoryBlocks ... ## What changes were proposed in this pull request? This patch modifies Spark's `MemoryAllocator` implementations so that `free(MemoryBlock)` mutates the passed block to clear pointers (in the off-heap case) or null out references to backing `long[]` arrays (in the on-heap case). The goal of this change is to add an extra layer of defense against use-after-free bugs because currently it's hard to detect corruption caused by blind writes to freed memory blocks. ## How was this patch tested? New unit tests in `PlatformSuite`, including new tests for existing functionality because we did not have sufficient mutation coverage of the on-heap memory allocator's pooling logic. Author: Josh Rosen <joshrosen@databricks.com> Closes #20191 from JoshRosen/SPARK-22997-add-defenses-against-use-after-free-bugs-in-memory-allocator.		2018-01-10 00:45:47 -08:00
..
src	[SPARK-22997] Add additional defenses against use of freed MemoryBlocks	2018-01-10 00:45:47 -08:00
pom.xml	[SPARK-22066][BUILD] Update checkstyle to 8.2, enable it, fix violations	2017-09-20 10:01:46 +01:00