[dfsan] Add origin tls/move/read APIs
authorJianzhou Zhao <jianzhouzh@google.com>
Fri, 12 Feb 2021 00:29:58 +0000 (00:29 +0000)
committerJianzhou Zhao <jianzhouzh@google.com>
Thu, 18 Feb 2021 17:48:20 +0000 (17:48 +0000)
commit063a6fa87ece8a452daba99df7fb99751ed10165
treec1130f113658e9fe41df562a533897484b0fde39
parent1b8d2ec07142d3517c0236064b1b8d281319b02a
[dfsan] Add origin tls/move/read APIs

This is a part of https://reviews.llvm.org/D95835.

Added
1) TLS storage
2) a weak global used to set by instrumented code
3) move origins

These APIs are similar to MSan's APIs
  https://github.com/llvm/llvm-project/blob/main/compiler-rt/lib/msan/msan_poisoning.cpp
We first improved MSan's by https://reviews.llvm.org/D94572 and https://reviews.llvm.org/D94552.
So the correctness has been verified by MSan.
After the DFSan instrument code is ready, we wil be adding more test
cases

4) read

To reduce origin tracking cost, some of the read APIs return only
the origin from the first taint data.

Note that we did not add origin set APIs here because they are related
to code instrumentation, will be added later with IR transformation
code.

Reviewed-by: morehouse
Differential Revision: https://reviews.llvm.org/D96564
compiler-rt/lib/dfsan/dfsan.cpp
compiler-rt/lib/dfsan/dfsan.h