Adds the basic instrumentation needed for stack tagging.
Currently does not support stack short granules or TLS stack histories,
since a different code path is followed for the callback instrumentation
we use.
We may simply wait to support these two features until we switch to
a custom calling convention.
Patch By: xiangzhangllvm, morehouse
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D102901
In LAM model X86_64 will use bits 57-62 (of 0-63) as HWASAN tag.
So here we make sure the tag shift position and tag mask is correct for x86-64.
Differential Revision: https://reviews.llvm.org/D102472
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
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
Subsequent patches will implement page-aliasing mode for x86_64, which
will initially only work for the primary heap allocator. We force
callback instrumentation to simplify the initial aliasing
implementation.
Reviewed By: vitalybuka, eugenis
Differential Revision: https://reviews.llvm.org/D98069
Summary:
Porting HWASan to Linux x86-64, first of the three patches, LLVM part.
The approach is similar to ARM case, trap signal is used to communicate
memory tag check failure. int3 instruction is used to generate a signal,
access parameters are stored in nop [eax + offset] instruction immediately
following the int3 one.
One notable difference is that x86-64 has to untag the pointer before use
due to the lack of feature comparable to ARM's TBI (Top Byte Ignore).
Reviewers: eugenis
Subscribers: kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D44699
llvm-svn: 328342
Matt Morehouse