diff options
| author | Matthew Maurer <mmaurer@google.com> | 2024-09-12 21:00:44 +0200 |
|---|---|---|
| committer | Miguel Ojeda <ojeda@kernel.org> | 2024-09-16 17:29:58 +0200 |
| commit | ca627e636551e74b528f150d744f67d9a63f0ae7 (patch) | |
| tree | a90dfd448998e8e96fbd8a35a6cbc412ade5d48b /init | |
| parent | ce4a2620985cdf06c200ec0b6dce80374237697c (diff) | |
rust: cfi: add support for CFI_CLANG with Rust
Make it possible to use the Control Flow Integrity (CFI) sanitizer when
Rust is enabled. Enabling CFI with Rust requires that CFI is configured
to normalize integer types so that all integer types of the same size
and signedness are compatible under CFI.
Rust and C use the same LLVM backend for code generation, so Rust KCFI
is compatible with the KCFI used in the kernel for C. In the case of
FineIBT, CFI also depends on -Zpatchable-function-entry for rewriting
the function prologue, so we set that flag for Rust as well. The flag
for FineIBT requires rustc 1.80.0 or later, so include a Kconfig
requirement for that.
Enabling Rust will select CFI_ICALL_NORMALIZE_INTEGERS because the flag
is required to use Rust with CFI. Using select rather than `depends on`
avoids the case where Rust is not visible in menuconfig due to
CFI_ICALL_NORMALIZE_INTEGERS not being enabled. One disadvantage of
select is that RUST must `depends on` all of the things that
CFI_ICALL_NORMALIZE_INTEGERS depends on to avoid invalid configurations.
Alice has been using KCFI on her phone for several months, so it is
reasonably well tested on arm64.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Gatlin Newhouse <gatlin.newhouse@gmail.com>
Acked-by: Kees Cook <kees@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240801-kcfi-v2-2-c93caed3d121@google.com
[ Replaced `!FINEIBT` requirement with `!CALL_PADDING` to prevent
a build error on older Rust compilers. Fixed typo. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Diffstat (limited to 'init')
| -rw-r--r-- | init/Kconfig | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/init/Kconfig b/init/Kconfig index 9bcda3b0a20f..53f4589b7847 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1905,11 +1905,13 @@ config RUST bool "Rust support" depends on HAVE_RUST depends on RUST_IS_AVAILABLE - depends on !CFI_CLANG depends on !MODVERSIONS depends on !GCC_PLUGIN_RANDSTRUCT depends on !RANDSTRUCT depends on !DEBUG_INFO_BTF || PAHOLE_HAS_LANG_EXCLUDE + depends on !CFI_CLANG || RUSTC_VERSION >= 107900 && $(cc-option,-fsanitize=kcfi -fsanitize-cfi-icall-experimental-normalize-integers) + select CFI_ICALL_NORMALIZE_INTEGERS if CFI_CLANG + depends on !CALL_PADDING || RUSTC_VERSION >= 108000 help Enables Rust support in the kernel. |