When using the shadow call stack sanitizer, all code must be compiled with the -ffixed-x18 flag, but this flag is not currently being passed to Rust. This results in crashes that are extremely difficult to debug.
To ensure that nobody else has to go through the same debugging session that I had to, prevent configurations that enable both SHADOW_CALL_STACK and RUST.
It is rather common for people to backport 724a75ac9542 ("arm64: rust: Enable Rust support for AArch64"), so I recommend applying this fix all the way back to 6.1.
Cc: stable@vger.kernel.org # 6.1 and later Fixes: 724a75ac9542 ("arm64: rust: Enable Rust support for AArch64") Signed-off-by: Alice Ryhl aliceryhl@google.com --- init/Kconfig | 1 + 1 file changed, 1 insertion(+)
diff --git a/init/Kconfig b/init/Kconfig index b0238c4b6e79..914edf51b068 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1909,6 +1909,7 @@ config RUST depends on !MODVERSIONS depends on !GCC_PLUGINS depends on !RANDSTRUCT + depends on !SHADOW_CALL_STACK depends on !DEBUG_INFO_BTF || PAHOLE_HAS_LANG_EXCLUDE help Enables Rust support in the kernel.