value() has undesired exception checking semantics and calls
__throw_bad_optional_access in libc++. Moreover, the API is unavailable without
_LIBCPP_NO_EXCEPTIONS on older Mach-O platforms (see
_LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS).
This fixes clang.
Only mark functions that have address-taken locals
as requiring UAR checking.
On a large internal app this reduces number of marked functions
from 78441 to 66618. Mostly small, trivial getter/setter-type
functions are unmarked, but also some amount of larger
number-crunching-type functions are unmarked as well.
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D139811
Currently per-function metadata consists of:
(start-pc, size, features)
This adds a new UAR feature and if it's set an additional element:
(start-pc, size, features, stack-args-size)
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D136078
D130887 uses a dummy empty section `sanmd_covered` (with the SHF_GNU_RETAIN flag on
ELF) to prevent `undefined symbol: __start_sanmd_covered` if all `sanmd_covered`
are discarded by `ld --gc-sections` (in `-z start-stop-gc` mode).
The dummy `sanmd_covered` does not have the SHF_LINK_ORDER flag, so mixing it
with SHF_LINK_ORDER `sanmd_covered` causes an issue to GNU ld<2.36
(https://sourceware.org/bugzilla/show_bug.cgi?id=26256).
Similar to D98903 for SanitizerCoverage, let's make encapsulation symbols
undefined weak[1]. This additionally avoids size cost due to the dummy section and
symbol.
[1]: https://maskray.me/blog/2021-01-31-metadata-sections-comdat-and-shf-link-order
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D139276
Currently per-function metadata consists of:
(start-pc, size, features)
This adds a new UAR feature and if it's set an additional element:
(start-pc, size, features, stack-args-size)
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D136078
Currently per-function metadata consists of:
(start-pc, size, features)
This adds a new UAR feature and if it's set an additional element:
(start-pc, size, features, stack-args-size)
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D136078
This reverts commit a1255dc467f7ce57a966efa76bbbb4ee91d9115a.
This patch results in:
llvm/lib/CodeGen/SanitizerBinaryMetadata.cpp:57:17: error: no member
named 'size' in 'llvm::MDTuple'
Currently per-function metadata consists of:
(start-pc, size, features)
This adds a new UAR feature and if it's set an additional element:
(start-pc, size, features, stack-args-size)
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D136078
Introduces the SanitizerBinaryMetadata instrumentation pass which uses
the new MD_pcsections metadata kinds to instrument certain types of
instructions and functions required for breakpoint-based sanitizers.
The first intended user of the binary metadata emitted will be a variant
of GWP-TSan [1]. GWP-TSan will require information about atomic
accesses; to unambiguously determine if an access is atomic or not, we
also require "covered" information which code has been compiled with
SanitizerBinaryMetadata instrumentation enabled.
[1] https://llvm.org/devmtg/2020-09/slides/Morehouse-GWP-Tsan.pdf
Reviewed By: dvyukov
Differential Revision: https://reviews.llvm.org/D130887
