Revision (<<< Hide revision tags) (Show revision tags >>>) Date Author Comments
Revision tags: llvmorg-18.1.8, llvmorg-18.1.7, llvmorg-18.1.6, llvmorg-18.1.5, llvmorg-18.1.4, llvmorg-18.1.3, llvmorg-18.1.2, llvmorg-18.1.1, llvmorg-18.1.0, llvmorg-18.1.0-rc4, llvmorg-18.1.0-rc3, llvmorg-18.1.0-rc2, llvmorg-18.1.0-rc1, llvmorg-19-init, llvmorg-17.0.6, llvmorg-17.0.5, llvmorg-17.0.4, llvmorg-17.0.3, llvmorg-17.0.2, llvmorg-17.0.1, llvmorg-17.0.0
# 0a1aa6cd 14-Sep-2023 Arthur Eubanks <aeubanks@google.com>

[NFC][CodeGen] Change CodeGenOpt::Level/CodeGenFileType into enum classes (#66295)

This will make it easy for callers to see issues with and fix up calls
to createTargetMachine after a future chang

[NFC][CodeGen] Change CodeGenOpt::Level/CodeGenFileType into enum classes (#66295)

This will make it easy for callers to see issues with and fix up calls
to createTargetMachine after a future change to the params of
TargetMachine.

This matches other nearby enums.

For downstream users, this should be a fairly straightforward
replacement,
e.g. s/CodeGenOpt::Aggressive/CodeGenOptLevel::Aggressive
or s/CGFT_/CodeGenFileType::

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Revision tags: llvmorg-17.0.0-rc4, llvmorg-17.0.0-rc3, llvmorg-17.0.0-rc2, llvmorg-17.0.0-rc1, llvmorg-18-init, llvmorg-16.0.6, llvmorg-16.0.5, llvmorg-16.0.4, llvmorg-16.0.3, llvmorg-16.0.2, llvmorg-16.0.1, llvmorg-16.0.0, llvmorg-16.0.0-rc4, llvmorg-16.0.0-rc3, llvmorg-16.0.0-rc2, llvmorg-16.0.0-rc1, llvmorg-17-init, llvmorg-15.0.7, llvmorg-15.0.6, llvmorg-15.0.5, llvmorg-15.0.4, llvmorg-15.0.3, working, llvmorg-15.0.2, llvmorg-15.0.1, llvmorg-15.0.0, llvmorg-15.0.0-rc3, llvmorg-15.0.0-rc2, llvmorg-15.0.0-rc1, llvmorg-16-init, llvmorg-14.0.6, llvmorg-14.0.5, llvmorg-14.0.4, llvmorg-14.0.3, llvmorg-14.0.2, llvmorg-14.0.1, llvmorg-14.0.0, llvmorg-14.0.0-rc4, llvmorg-14.0.0-rc3, llvmorg-14.0.0-rc2, llvmorg-14.0.0-rc1, llvmorg-15-init, llvmorg-13.0.1, llvmorg-13.0.1-rc3, llvmorg-13.0.1-rc2, llvmorg-13.0.1-rc1, llvmorg-13.0.0, llvmorg-13.0.0-rc4, llvmorg-13.0.0-rc3, llvmorg-13.0.0-rc2, llvmorg-13.0.0-rc1, llvmorg-14-init, llvmorg-12.0.1, llvmorg-12.0.1-rc4, llvmorg-12.0.1-rc3, llvmorg-12.0.1-rc2, llvmorg-12.0.1-rc1, llvmorg-12.0.0, llvmorg-12.0.0-rc5, llvmorg-12.0.0-rc4, llvmorg-12.0.0-rc3, llvmorg-12.0.0-rc2, llvmorg-11.1.0, llvmorg-11.1.0-rc3, llvmorg-12.0.0-rc1, llvmorg-13-init, llvmorg-11.1.0-rc2, llvmorg-11.1.0-rc1, llvmorg-11.0.1, llvmorg-11.0.1-rc2, llvmorg-11.0.1-rc1, llvmorg-11.0.0, llvmorg-11.0.0-rc6, llvmorg-11.0.0-rc5, llvmorg-11.0.0-rc4, llvmorg-11.0.0-rc3
# cd461512 16-Sep-2020 Simon Pilgrim <llvm-dev@redking.me.uk>

[X86] Assert that we've found a terminator instruction. NFCI.

Fixes clang static analayzer null dereference warning.


Revision tags: llvmorg-11.0.0-rc2, llvmorg-11.0.0-rc1, llvmorg-12-init, llvmorg-10.0.1, llvmorg-10.0.1-rc4, llvmorg-10.0.1-rc3, llvmorg-10.0.1-rc2, llvmorg-10.0.1-rc1
# 9d9e4998 13-May-2020 Zola Bridges <zbrid@google.com>

[x86][seses] Add clang flag; Use lvi-cfi with seses

This patch creates a clang flag to enable SESES. This flag also ensures that
lvi-cfi is on when using seses via clang.

SESES should use lvi-cfi t

[x86][seses] Add clang flag; Use lvi-cfi with seses

This patch creates a clang flag to enable SESES. This flag also ensures that
lvi-cfi is on when using seses via clang.

SESES should use lvi-cfi to mitigate returns and indirect branches.

The flag to enable the SESES functionality only without lvi-cfi is now
-x86-seses-enable-without-lvi-cfi to warn users part of the mitigation is not
enabled if they use this flag. This is useful in case folks want to see the
cost of SESES separate from the LVI-CFI.

Reviewed By: sconstab

Differential Revision: https://reviews.llvm.org/D79910

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# dfabffb1 17-Jun-2020 Zola Bridges <zbrid@google.com>

[x86][lvi][seses] Use SESES at O0 for LVI mitigation

Use SESES as the fallback at O0 where the optimized LVI pass isn't desired due
to its effect on build times at O0.

I updated the LVI tests since

[x86][lvi][seses] Use SESES at O0 for LVI mitigation

Use SESES as the fallback at O0 where the optimized LVI pass isn't desired due
to its effect on build times at O0.

I updated the LVI tests since this changes the code gen for the tests touched in the parent revision.

This is a follow up to the comments I made here: https://reviews.llvm.org/D80964

Hopefully we can continue the discussion here.

Also updated SESES to handle LFENCE instructions properly instead of adding
redundant LFENCEs. In particular, 1) no longer add LFENCE if the current
instruction being processed is an LFENCE and 2) no longer add LFENCE if the
instruction right before the instruction being processed is an LFENCE

Reviewed By: sconstab

Differential Revision: https://reviews.llvm.org/D82037

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# 12938749 01-Jul-2020 Wolfgang Pieb <wolfgang_pieb@playstation.sony.com>

Correct 3 spelling errors in headers and doc strings.


# bf95cf4a 11-May-2020 Zola Bridges <zbrid@google.com>

[x86][seses] Introduce SESES pass for LVI

This is an implementation of Speculative Execution Side Effect
Suppression which is intended as a last resort mitigation against Load
Value Injection, LVI,

[x86][seses] Introduce SESES pass for LVI

This is an implementation of Speculative Execution Side Effect
Suppression which is intended as a last resort mitigation against Load
Value Injection, LVI, a newly disclosed speculative execution side
channel vulnerability.

One pager:
https://software.intel.com/security-software-guidance/software-guidance/load-value-injection

Deep dive:
https://software.intel.com/security-software-guidance/insights/deep-dive-load-value-injection

The mitigation consists of a compiler pass that inserts an LFENCE before
each memory read instruction, memory write instruction, and the first
branch instruction in a group of terminators at the end of a basic
block. The goal is to prevent speculative execution, potentially based
on misspeculated conditions and/or containing secret data, from leaking
that data via side channels embedded in such instructions.

This is something of a last-resort mitigation: it is expected to have
extreme performance implications and it may not be a complete mitigation
due to trying to enumerate side channels.

In addition to the full version of the mitigation, this patch
implements three flags to turn off part of the mitigation. These flags
are disabled by default. The flags are not intended to result in a
secure variant of the mitigation. The flags are intended to be used by
users who would like to experiment with improving the performance of
the mitigation. I ran benchmarks with each of these flags enabled in
order to find if there was any room for further optimization of LFENCE
placement with respect to LVI.

Performance Testing Results

When applying this mitigation to BoringSSL, we see the following
results. These are a summary/aggregation of the performance changes when
this mitigation is applied versus when no mitigation is applied.

Fully Mitigated vs Baseline
Geometric mean
0.071 (Note: This can be read as the ops/s of the mitigated
program was 7.1% of the ops/s of the unmitigated program.)
Minimum
0.041
Quartile 1
0.060
Median
0.063
Quartile 3
0.077
Maximum
0.230

Reviewed By: george.burgess.iv

Differential Revision: https://reviews.llvm.org/D75939

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