[PATCH v3] rust: make mutually exclusive with CFI_CLANG

[Conor Dooley]

From: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>

On RISC-V and arm64, and presumably x86, if CFI_CLANG is enabled,
loading a rust module will trigger a kernel panic. Support for
sanitisers, including kcfi (CFI_CLANG), is in the works, but for now
they're nightly-only options in rustc. Make RUST depend on !CFI_CLANG
to prevent configuring a kernel without symmetrical support for kfi.

Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support")
cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
---
Sending this one on its own, there's no explicit dep on this for the
riscv enabling patch, v3 to continue the numbering from there. Nothing
has changed since v2.

CC: Miguel Ojeda <ojeda@xxxxxxxxxx>
CC: Alex Gaynor <alex.gaynor@xxxxxxxxx>
CC: Wedson Almeida Filho <wedsonaf@xxxxxxxxx>
CC: linux-kernel@xxxxxxxxxxxxxxx (open list)
CC: rust-for-linux@xxxxxxxxxxxxxxx
CC: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
CC: Kees Cook <keescook@xxxxxxxxxxxx>
CC: Nathan Chancellor <nathan@xxxxxxxxxx>
CC: llvm@xxxxxxxxxxxxxxx
---
 init/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/init/Kconfig b/init/Kconfig
index aa02aec6aa7d..ad9a2da27dc9 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1899,6 +1899,7 @@ config RUST
 	bool "Rust support"
 	depends on HAVE_RUST
 	depends on RUST_IS_AVAILABLE
+	depends on !CFI_CLANG
 	depends on !MODVERSIONS
 	depends on !GCC_PLUGINS
 	depends on !RANDSTRUCT
-- 
2.43.0