summaryrefslogtreecommitdiff
path: root/arch/Kconfig
diff options
context:
space:
mode:
authorAlice Ryhl <aliceryhl@google.com>2024-10-10 09:38:27 +0000
committerMiguel Ojeda <ojeda@kernel.org>2024-10-13 22:23:13 +0200
commit8b8ca9c25fe69c2162e3235c7d6c341127abeed6 (patch)
treedfa5000a62e26a678291c960408368b253a9e85f /arch/Kconfig
parentaf0121c2d303111d363c62e40413ffb39d5dc0f1 (diff)
cfi: fix conditions for HAVE_CFI_ICALL_NORMALIZE_INTEGERSrust-fixes-6.12-2
The HAVE_CFI_ICALL_NORMALIZE_INTEGERS option has some tricky conditions when KASAN or GCOV are turned on, as in that case we need some clang and rustc fixes [1][2] to avoid boot failures. The intent with the current setup is that you should be able to override the check and turn on the option if your clang/rustc has the fix. However, this override does not work in practice. Thus, use the new RUSTC_LLVM_VERSION to correctly implement the check for whether the fix is available. Additionally, remove KASAN_HW_TAGS from the list of incompatible options. The CFI_ICALL_NORMALIZE_INTEGERS option is incompatible with KASAN because LLVM will emit some constructors when using KASAN that are assigned incorrect CFI tags. These constructors are emitted due to use of -fsanitize=kernel-address or -fsanitize=kernel-hwaddress that are respectively passed when KASAN_GENERIC or KASAN_SW_TAGS are enabled. However, the KASAN_HW_TAGS option relies on hardware support for MTE instead and does not pass either flag. (Note also that KASAN_HW_TAGS does not `select CONSTRUCTORS`.) Link: https://github.com/llvm/llvm-project/pull/104826 [1] Link: https://github.com/rust-lang/rust/pull/129373 [2] Fixes: 4c66f8307ac0 ("cfi: encode cfi normalized integers + kasan/gcov bug in Kconfig") Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20241010-icall-detect-vers-v1-2-8f114956aa88@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Diffstat (limited to 'arch/Kconfig')
-rw-r--r--arch/Kconfig26
1 files changed, 12 insertions, 14 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index 8af374ea1adc..00163e4a237c 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -838,7 +838,7 @@ config CFI_CLANG
config CFI_ICALL_NORMALIZE_INTEGERS
bool "Normalize CFI tags for integers"
depends on CFI_CLANG
- depends on HAVE_CFI_ICALL_NORMALIZE_INTEGERS
+ depends on HAVE_CFI_ICALL_NORMALIZE_INTEGERS_CLANG
help
This option normalizes the CFI tags for integer types so that all
integer types of the same size and signedness receive the same CFI
@@ -851,21 +851,19 @@ config CFI_ICALL_NORMALIZE_INTEGERS
This option is necessary for using CFI with Rust. If unsure, say N.
-config HAVE_CFI_ICALL_NORMALIZE_INTEGERS
- def_bool !GCOV_KERNEL && !KASAN
- depends on CFI_CLANG
+config HAVE_CFI_ICALL_NORMALIZE_INTEGERS_CLANG
+ def_bool y
depends on $(cc-option,-fsanitize=kcfi -fsanitize-cfi-icall-experimental-normalize-integers)
- help
- Is CFI_ICALL_NORMALIZE_INTEGERS supported with the set of compilers
- currently in use?
+ # With GCOV/KASAN we need this fix: https://github.com/llvm/llvm-project/pull/104826
+ depends on CLANG_VERSION >= 190000 || (!GCOV_KERNEL && !KASAN_GENERIC && !KASAN_SW_TAGS)
- This option defaults to false if GCOV or KASAN is enabled, as there is
- an LLVM bug that makes normalized integers tags incompatible with
- KASAN and GCOV. Kconfig currently does not have the infrastructure to
- detect whether your rustc compiler contains the fix for this bug, so
- it is assumed that it doesn't. If your compiler has the fix, you can
- explicitly enable this option in your config file. The Kconfig logic
- needed to detect this will be added in a future kernel release.
+config HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
+ def_bool y
+ depends on HAVE_CFI_ICALL_NORMALIZE_INTEGERS_CLANG
+ depends on RUSTC_VERSION >= 107900
+ # With GCOV/KASAN we need this fix: https://github.com/rust-lang/rust/pull/129373
+ depends on (RUSTC_LLVM_VERSION >= 190000 && RUSTC_VERSION >= 108200) || \
+ (!GCOV_KERNEL && !KASAN_GENERIC && !KASAN_SW_TAGS)
config CFI_PERMISSIVE
bool "Use CFI in permissive mode"