[PATCH] D66189: [GWP-ASan] Implement stack frame compression.

[Mitch Phillips via Phabricator via llvm-commits]

hctim created this revision.
hctim added a reviewer: vlad.tsyrklevich.
Herald added subscribers: llvm-commits, Sanitizers, mgorny.
Herald added projects: Sanitizers, LLVM.

This patch introduces stack frame compression to GWP-ASan. Each stack frame is
variable-length integer encoded as the difference between frame[i] and
frame[i - 1]. Furthermore, we use zig-zag encoding on the difference to ensure
that negative differences are also encoded into a relatively small number of
bytes.

Examples of what the compression looks like can be seen in
`gwp_asan/tests/compression.cpp`.

This compression can reduce the memory consumption cost of stack traces by
~50%.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D66189

Files:
  compiler-rt/lib/gwp_asan/CMakeLists.txt
  compiler-rt/lib/gwp_asan/guarded_pool_allocator.cpp
  compiler-rt/lib/gwp_asan/guarded_pool_allocator.h
  compiler-rt/lib/gwp_asan/options.inc
  compiler-rt/lib/gwp_asan/stack_trace_compressor.cpp
  compiler-rt/lib/gwp_asan/stack_trace_compressor.h
  compiler-rt/lib/gwp_asan/stack_trace_compressor_fuzzer.cpp
  compiler-rt/lib/gwp_asan/tests/compression.cpp

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