Update the hardware CRC32 logic in scudo to support using `-mcrc32`
instead of `-msse4.2`. The CRC32 intrinsics use the former flag
in the newer compiler versions, e.g. in clang since 12fa608af4.
With these versions of clang, passing `-msse4.2` is insufficient
to enable the instructions and causes build failures when `-march` does
not enable CRC32 implicitly:
/var/tmp/portage/sys-libs/compiler-rt-sanitizers-14.0.0/work/compiler-rt/lib/scudo/scudo_crc32.cpp:20:10: error: always_inline function '_mm_crc32_u32' requires target feature 'crc32', but would be inlined into function 'computeHardwareCRC32' that is compiled without support for 'crc32'
return CRC32_INTRINSIC(Crc, Data);
^
/var/tmp/portage/sys-libs/compiler-rt-sanitizers-14.0.0/work/compiler-rt/lib/scudo/scudo_crc32.h:27:27: note: expanded from macro 'CRC32_INTRINSIC'
# define CRC32_INTRINSIC FIRST_32_SECOND_64(_mm_crc32_u32, _mm_crc32_u64)
^
/var/tmp/portage/sys-libs/compiler-rt-sanitizers-14.0.0/work/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_platform.h:132:36: note: expanded from macro 'FIRST_32_SECOND_64'
# define FIRST_32_SECOND_64(a, b) (a)
^
1 error generated.
For backwards compatibility, use `-mcrc32` when available and fall back
to `-msse4.2`. The `<smmintrin.h>` header remains in use as it still
works and is compatible with GCC, while clang's `<crc32intrin.h>`
is not.
Use __builtin_ia32*() rather than _mm_crc32*() when using `-mcrc32`
to preserve compatibility with GCC. _mm_crc32*() are aliases
to __builtin_ia32*() in both compilers but GCC requires `-msse4.2`
for the former, while both use `-mcrc32` for the latter.
Originally reported in https://bugs.gentoo.org/835870.
Differential Revision: https://reviews.llvm.org/D122789
This reverts commit 09b53121c3.
Breaks the build with GCC 11.2 on x86_64:
In file included from /home/npopov/repos/llvm-project/compiler-rt/lib/scudo/scudo_crc32.h:27,
from /home/npopov/repos/llvm-project/compiler-rt/lib/scudo/scudo_crc32.cpp:14:
/usr/lib/gcc/x86_64-redhat-linux/11/include/smmintrin.h: In function ‘__sanitizer::u32 __scudo::computeHardwareCRC32(__sanitizer::u32, __sanitizer::uptr)’:
/usr/lib/gcc/x86_64-redhat-linux/11/include/smmintrin.h:846:1: error: inlining failed in call to ‘always_inline’ ‘long long unsigned int _mm_crc32_u64(long long unsigned int, long long unsigned int)’: target specific option mismatch
846 | _mm_crc32_u64 (unsigned long long __C, unsigned long long __V)
Update the hardware CRC32 logic in scudo to support using `-mcrc32`
instead of `-msse4.2`. The CRC32 intrinsics use the former flag
in the newer compiler versions, e.g. in clang since 12fa608af4.
With these compilers, passing `-msse4.2` is insufficient to enable
the instructions and causes build failures when `-march` does not enable
CRC32:
/var/tmp/portage/sys-libs/compiler-rt-sanitizers-14.0.0/work/compiler-rt/lib/scudo/scudo_crc32.cpp:20:10: error: always_inline function '_mm_crc32_u32' requires target feature 'crc32', but would be inlined into function 'computeHardwareCRC32' that is compiled without support for 'crc32'
return CRC32_INTRINSIC(Crc, Data);
^
/var/tmp/portage/sys-libs/compiler-rt-sanitizers-14.0.0/work/compiler-rt/lib/scudo/scudo_crc32.h:27:27: note: expanded from macro 'CRC32_INTRINSIC'
# define CRC32_INTRINSIC FIRST_32_SECOND_64(_mm_crc32_u32, _mm_crc32_u64)
^
/var/tmp/portage/sys-libs/compiler-rt-sanitizers-14.0.0/work/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_platform.h:132:36: note: expanded from macro 'FIRST_32_SECOND_64'
# define FIRST_32_SECOND_64(a, b) (a)
^
1 error generated.
For backwards compatibility, use `-mcrc32` when available and fall back
to `-msse4.2`. The `<smmintrin.h>` header remains in use as it still
works and is compatible with GCC, while clang's `<crc32intrin.h>`
is not.
Originally reported in https://bugs.gentoo.org/835870.
Differential Revision: https://reviews.llvm.org/D122789
Here "memory initialization" refers to zero- or pattern-init on
non-MTE hardware, or (where possible to avoid) memory tagging on MTE
hardware. With shared TSD the per-thread memory initialization state
is stored in bit 0 of the TLS slot, similar to PointerIntPair in LLVM.
Differential Revision: https://reviews.llvm.org/D87739
Summary:
In order to be compliant with tcmalloc's extension ownership
determination function, we have to expose a function that will
say if a chunk was allocated by us.
As to whether or not this has security consequences: someone
able to call this function repeatedly could use it to determine
secrets (cookie) or craft a valid header. So this should not be
exposed directly to untrusted user input.
Add related tests.
Additionally clang-format caught a few things to change.
Reviewers: hctim, pcc, cferris, eugenis, vitalybuka
Subscribers: JDevlieghere, jfb, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D70908
The macros INLINE and COMPILER_CHECK always expand to the same thing (inline
and static_assert respectively). Both expansions are standards compliant C++
and are used consistently in the rest of LLVM, so let's improve consistency
with the rest of LLVM by replacing them with the expansions.
Differential Revision: https://reviews.llvm.org/D70793
Summary:
This introduces a bunch of small optimizations with the purpose of
making the fastpath tighter:
- tag more conditions as `LIKELY`/`UNLIKELY`: as a rule of thumb we
consider that every operation related to the secondary is unlikely
- attempt to reduce the number of potentially extraneous instructions
- reorganize the `Chunk` header to not straddle a word boundary and
use more appropriate types
Note that some `LIKELY`/`UNLIKELY` impact might be less obvious as
they are in slow paths (for example in `secondary.cc`), but at this
point I am throwing a pretty wide net, and it's consistant and doesn't
hurt.
This was mosly done for the benfit of Android, but other platforms
benefit from it too. An aarch64 Android benchmark gives:
- before:
```
BM_youtube/min_time:15.000/repeats:4/manual_time_mean 445244 us 659385 us 4
BM_youtube/min_time:15.000/repeats:4/manual_time_median 445007 us 658970 us 4
BM_youtube/min_time:15.000/repeats:4/manual_time_stddev 885 us 1332 us 4
```
- after:
```
BM_youtube/min_time:15.000/repeats:4/manual_time_mean 415697 us 621925 us 4
BM_youtube/min_time:15.000/repeats:4/manual_time_median 415913 us 622061 us 4
BM_youtube/min_time:15.000/repeats:4/manual_time_stddev 990 us 1163 us 4
```
Additional since `-Werror=conversion` is enabled on some platforms we
are built on, enable it upstream to catch things early: a few sign
conversions had slept through and needed additional casting.
Reviewers: hctim, morehouse, eugenis, vitalybuka
Reviewed By: vitalybuka
Subscribers: srhines, mgorny, javed.absar, kristof.beyls, delcypher, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D64664
llvm-svn: 366918
Summary:
A few corrections:
- rename `TransferBatch::MaxCached` to `getMaxCached` to conform with
the style guide;
- move `getBlockBegin` from `Chunk::` to `Allocator::`: I believe it
was a fallacy to have this be a `Chunk` method, as chunks'
relationship to backend blocks are up to the frontend allocator. It
makes more sense now, particularly with regard to the offset. Update
the associated chunk test as the method isn't available there
anymore;
- add a forgotten `\n` to a log string;
- for `releaseToOs`, instead of starting at `1`, start at `0` and
`continue` on `BatchClassId`: in the end it's identical but doesn't
assume a particular class id for batches;
- change a `CHECK` to a `reportOutOfMemory`: it's a clearer message
Reviewers: hctim, morehouse, eugenis, vitalybuka
Reviewed By: hctim
Subscribers: delcypher, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D64570
llvm-svn: 365816
Summary:
... and its related functions.
The structure and its functionalities are identical to existing ones.
The header stores information on a `scudo::Chunk` to be able to detect
inconsitencies or potential corruption attempts. It is checksummed for
that purpose.
Reviewers: morehouse, eugenis, vitalybuka, hctim
Reviewed By: vitalybuka
Subscribers: mgorny, delcypher, jfb, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D61654
llvm-svn: 360290
Mitch Phillips