This patch series makes it possible to use Rust together with the shadow call stack sanitizer. The first patch is intended to be backported to ensure that people don't try to use SCS with Rust on older kernel versions. The second patch makes it possible to use Rust with the shadow call stack sanitizer.
The second patch in this series depends on the next version of [1], which Miguel will send soon.
Link: https://lore.kernel.org/rust-for-linux/20240709160615.998336-12-ojeda@kernel... [1] Signed-off-by: Alice Ryhl aliceryhl@google.com --- Changes in v4: - Move `depends on` to CONFIG_RUST. - Rewrite commit messages to include more context. - Link to v3: https://lore.kernel.org/r/20240704-shadow-call-stack-v3-0-d11c7a6ebe30@googl...
Changes in v3: - Use -Zfixed-x18. - Add logic to reject unsupported rustc versions. - Also include a fix to be backported. - Link to v2: https://lore.kernel.org/rust-for-linux/20240305-shadow-call-stack-v2-1-c7b4a...
Changes in v2: - Add -Cforce-unwind-tables flag. - Link to v1: https://lore.kernel.org/rust-for-linux/20240304-shadow-call-stack-v1-1-f055e...
--- Alice Ryhl (2): rust: SHADOW_CALL_STACK is incompatible with Rust rust: support for shadow call stack sanitizer
Makefile | 1 + arch/arm64/Makefile | 3 +++ init/Kconfig | 1 + 3 files changed, 5 insertions(+) --- base-commit: 9cde54ad2f7ac3cf84f65df605570c5a00afc82f change-id: 20240304-shadow-call-stack-9c197a4361d9
Best regards,
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.
On Mon, Jul 29, 2024 at 4:23 PM Alice Ryhl aliceryhl@google.com wrote:
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.
It should not hurt, and it is useful out-of-tree just in case -- if arm64 is picking it up (which would be ideal):
Acked-by: Miguel Ojeda ojeda@kernel.org
Otherwise, please let us know. Thanks!
Cheers, Miguel
On Mon, 29 Jul 2024 14:22:48 +0000, Alice Ryhl wrote:
This patch series makes it possible to use Rust together with the shadow call stack sanitizer. The first patch is intended to be backported to ensure that people don't try to use SCS with Rust on older kernel versions. The second patch makes it possible to use Rust with the shadow call stack sanitizer.
The second patch in this series depends on the next version of [1], which Miguel will send soon.
[...]
Applied to arm64 (for-next/fixes), thanks!
[1/2] rust: SHADOW_CALL_STACK is incompatible with Rust https://git.kernel.org/arm64/c/f126745da817
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Miguel Ojeda