> This change instruments Metaspace for ASan. Metaspace allocates memory using > `mmap`/`munmap` which ASan is not aware of. Fortunately ASan supports > applications [manually poisoning/unpoisoning > memory](https://github.com/google/sanitizers/wiki/AddressSanitizerManualPoisoning). > ASan is able to detect poisoned memory, similar to `use-after-free`, and > will raise an error similarly called `use-after-poison`. This provides and > extra layer of defense and confidence. > > The header `sanitizers/address.h` defines macros for poisoning/unpoisoning > memory regions. These macros can be used regardless of build mode. When ASan > is not available, they are implemented using a NOOP approach which still > compiles the arguments but does so such that they will be stripped out by the > compiler due to being unreachable. This helps with maintenance. > > This also has the added benefit of making > [LSan](https://bugs.openjdk.org/browse/JDK-8298445) more accurate and > deterministic, as LSan will not look for pointers to malloc memory in > poisoned memory regions. > > IMO the benefit of doing this greatly outweighs the cost.
Justin King has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits since the last revision: - Fix typo Signed-off-by: Justin King <jck...@google.com> - Merge remote-tracking branch 'upstream/master' into jdk-8298908 - Exclude more zapping when ASan is in use Signed-off-by: Justin King <jck...@google.com> - Instrument Metaspace for ASan Signed-off-by: Justin King <jck...@google.com> ------------- Changes: - all: https://git.openjdk.org/jdk/pull/11702/files - new: https://git.openjdk.org/jdk/pull/11702/files/956fc3f5..70907916 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=11702&range=02 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11702&range=01-02 Stats: 11025 lines in 712 files changed: 5540 ins; 2906 del; 2579 mod Patch: https://git.openjdk.org/jdk/pull/11702.diff Fetch: git fetch https://git.openjdk.org/jdk pull/11702/head:pull/11702 PR: https://git.openjdk.org/jdk/pull/11702
