Commit c0a454b9044f ("arm64/bti: Disable in kernel BTI when cross
section thunks are broken") disabled in-kernel BTI for GCC because it
omits a function's BTI landing pad when it determines that a function
can only ever reached by a direct branch. The observed failure was a
module whose init text landed far enough from its core text to need a
PLT, whose "br x16" then hit a function with no "bti c".
Note that behavior isn't GCC-specific: Clang 21 has started ommitting
landing pads as well.
Now that all the known BTI bugs have been sorted out, re-enable it for
GCC.
Signed-off-by: Josh Poimboeuf <[email protected]>
---
arch/arm64/Kconfig | 2 --
1 file changed, 2 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 2687b71438661..e150807b03016 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2114,8 +2114,6 @@ config ARM64_BTI_KERNEL
depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697
depends on !CC_IS_GCC || GCC_VERSION >= 100100
- # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671
- depends on !CC_IS_GCC
depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS)
help
Build the kernel with Branch Target Identification annotations
--
2.55.0
