6 Commits

Author SHA1 Message Date
Matt Morehouse
96a4167b4c [HWASan] Use page aliasing on x86_64.
Userspace page aliasing allows us to use middle pointer bits for tags
without untagging them before syscalls or accesses.  This should enable
easier experimentation with HWASan on x86_64 platforms.

Currently stack, global, and secondary heap tagging are unsupported.
Only primary heap allocations get tagged.

Note that aliasing mode will not work properly in the presence of
fork(), since heap memory will be shared between the parent and child
processes.  This mode is non-ideal; we expect Intel LAM to enable full
HWASan support on x86_64 in the future.

Reviewed By: vitalybuka, eugenis

Differential Revision: https://reviews.llvm.org/D98875
2021-03-25 07:04:14 -07:00
Matt Morehouse
c8ef98e5de Revert "[HWASan] Use page aliasing on x86_64."
This reverts commit 63f73c3eb9716256ab8dbb868e16d08a88636cba due to
breakage on aarch64 without TBI.
2021-03-24 16:18:29 -07:00
Matt Morehouse
63f73c3eb9 [HWASan] Use page aliasing on x86_64.
Userspace page aliasing allows us to use middle pointer bits for tags
without untagging them before syscalls or accesses.  This should enable
easier experimentation with HWASan on x86_64 platforms.

Currently stack, global, and secondary heap tagging are unsupported.
Only primary heap allocations get tagged.

Note that aliasing mode will not work properly in the presence of
fork(), since heap memory will be shared between the parent and child
processes.  This mode is non-ideal; we expect Intel LAM to enable full
HWASan support on x86_64 in the future.

Reviewed By: vitalybuka, eugenis

Differential Revision: https://reviews.llvm.org/D98875
2021-03-24 11:43:41 -07:00
Evgenii Stepanov
d1a6e4d2db [hwasan] Disable malloc-fill by default.
Summary: Non-zero malloc fill is causing way too many hard to debug issues.

Reviewers: kcc, pcc, hctim

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D81284
2020-06-05 11:27:16 -07:00
Peter Collingbourne
e757cadb07 hwasan: Untag global variable addresses in tests.
Once we start instrumenting globals, all addresses including those of string literals
that we pass to the operating system will start being tagged. Since we can't rely
on the operating system to be able to cope with these addresses, we need to untag
them before passing them to the operating system. This change introduces a macro
that does so and uses it everywhere it is needed.

Differential Revision: https://reviews.llvm.org/D65768

llvm-svn: 367938
2019-08-05 21:46:10 +00:00
Nico Weber
f9e0df071e compiler-rt: Rename .cc file in test/hwasan to .cpp
Like r367463, but for test/hwasan.

llvm-svn: 367849
2019-08-05 13:10:50 +00:00