rust: make mutually exclusive with CFI_CLANG

stable inclusion
from stable-v6.6.30
commit 3a9337459645c189a692be0c78bc8a6e5649b7d2
bugzilla: https://gitee.com/openeuler/kernel/issues/I9MPZ8

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3a9337459645c189a692be0c78bc8a6e5649b7d2

--------------------------------

commit 8933cf4651e02853ca679be7b2d978dfcdcc5e0c upstream.

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.

[ Matthew Maurer writes [1]:

    This patch is fine by me - the last patch needed for KCFI to be
    functional in Rust just landed upstream last night, so we should
    revisit this (in the form of enabling it) once we move to
    `rustc-1.79.0` or later.

  Ramon de C Valle also gave feedback [2] on the status of KCFI for
  Rust and created a tracking issue [3] in upstream Rust.   - Miguel ]

Fixes: 2f7ab12 ("Kbuild: add Rust support")
Cc: [email protected]
Signed-off-by: Conor Dooley <[email protected]>
Acked-by: Nathan Chancellor <[email protected]>
Link: https://lore.kernel.org/rust-for-linux/CAGSQo024u1gHJgzsO38Xg3c4or+JupoPABQx_+0BLEpPg0cOEA@mail.gmail.com/ [1]
Link: https://lore.kernel.org/rust-for-linux/CAOcBZOS2kPyH0Dm7Fuh4GC3=v7nZhyzBj_-dKu3PfAnrHZvaxg@mail.gmail.com/ [2]
Link: rust-lang/rust#123479 [3]
Link: https://lore.kernel.org/r/20240404-providing-emporium-e652e359c711@spud
[ Added feedback from the list, links, and used Cc for the tag. ]
Signed-off-by: Miguel Ojeda <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: ZhangPeng <[email protected]>

Author: ConchuOD

init/Kconfig

@@ -2054,6 +2054,7 @@ 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