Commit Graph

3 Commits

Author SHA1 Message Date
Evgeniy Stepanov b05d380451 [msan] Relax origin-alignment test.
Change origin-alignment test to test only the alignment of the origin
store, and not the exact instruction sequence used to compute the
address. This makes the test less fragile and, in particular, lets it
pass both with the old and new MSan ABIs.

llvm-svn: 254027
2015-11-24 21:44:16 +00:00
Evgeniy Stepanov d12212bc8c New MSan mapping layout (llvm part).
This is an implementation of
https://github.com/google/sanitizers/issues/579

It has a number of advantages over the current mapping:
* Works for non-PIE executables.
* Does not require ASLR; as a consequence, debugging MSan programs in
  gdb no longer requires "set disable-randomization off".
* Supports linux kernels >=4.1.2.
* The code is marginally faster and smaller.

This is an ABI break. We never really promised ABI stability, but
this patch includes a courtesy escape hatch: a compile-time macro
that reverts back to the old mapping layout.

llvm-svn: 249753
2015-10-08 21:35:26 +00:00
Evgeniy Stepanov d85ddee01d [msan] Avoid extra origin address realignment.
Do not realign origin address if the corresponding application
address is at least 4-byte-aligned.

Saves 2.5% code size in track-origins mode.

llvm-svn: 223464
2014-12-05 14:34:03 +00:00