[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
diff --git a/clang/docs/ClangCommandLineReference.rst b/clang/docs/ClangCommandLineReference.rst
index 672c4ae..0b56b7a 100644
--- a/clang/docs/ClangCommandLineReference.rst
+++ b/clang/docs/ClangCommandLineReference.rst
@@ -2755,6 +2755,10 @@
Make StdCall calling convention the default
+.. option:: -mseses, -mno-seses
+
+Enable speculative execution side effect suppression (SESES). Includes LVI control flow integrity mitigations
+
.. option:: -msign-return-address=<arg>
Select return address signing scope