The following commit has been merged into the x86/core branch of tip: Commit-ID: f6a2c2b2de817078ac5a7e58c10e746165e7825d Gitweb: https://git.kernel.org/tip/f6a2c2b2de817078ac5a7e58c10e746165e7825d Author: Nathan Chancellor <nathan@xxxxxxxxxx> AuthorDate: Fri, 18 Mar 2022 16:07:47 -07:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Tue, 22 Mar 2022 21:12:13 +01:00 x86/Kconfig: Only allow CONFIG_X86_KERNEL_IBT with ld.lld >= 14.0.0 With CONFIG_X86_KERNEL_IBT=y and a version of ld.lld prior to 14.0.0, there are numerous objtool warnings along the lines of: warning: objtool: .plt+0x6: indirect jump found in RETPOLINE build This is a known issue that has been resolved in ld.lld 14.0.0. Prevent CONFIG_X86_KERNEL_IBT from being selectable when using one of these problematic ld.lld versions. Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220318230747.3900772-3-nathan@xxxxxxxxxx --- arch/x86/Kconfig | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 921e4eb..8757926 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1875,6 +1875,8 @@ config X86_KERNEL_IBT prompt "Indirect Branch Tracking" bool depends on X86_64 && CC_HAS_IBT && STACK_VALIDATION + # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f + depends on !LD_IS_LLD || LLD_VERSION >= 140000 help Build the kernel with support for Indirect Branch Tracking, a hardware support course-grain forward-edge Control Flow Integrity
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