From: Nathan Chancellor Date: Thu, 12 Jun 2025 19:57:01 +0000 (-0700) Subject: riscv: Require clang-17 or newer for kCFI X-Git-Tag: v6.16-rc5~16^2^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6f49743af42ca43ef6d5487fc6d32f6184909430;p=thirdparty%2Flinux.git riscv: Require clang-17 or newer for kCFI After the combination of commit c217157bcd1d ("riscv: Implement HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS"), which starts using '-fpatchable-function-entry=M,N', and commit d0262e907e29 ("riscv: ftrace: support PREEMPT"), which allows CONFIG_DYNAMIC_FTRACE to be enabled by allmodconfig, allmodconfig builds with clang-16 begin crashing in the generic LLVM kCFI pass (see [1] for the stack trace). clang-17 avoids this crash by moving to target-specific lowering of the kCFI operand bundles [2]. Require clang-17 to select CONFIG_CFI_CLANG to avoid this crash. Fixes: c217157bcd1d ("riscv: Implement HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS") Link: https://godbolt.org/z/xG39Pn16o [1] Link: https://github.com/llvm/llvm-project/commit/62fa708ceb027713b386c7e0efda994f8bdc27e2 [2] Signed-off-by: Nathan Chancellor Reviewed-by: Sami Tolvanen Link: https://lore.kernel.org/r/20250612-riscv-require-clang-17-for-kcfi-v1-1-216f7cd7d87f@kernel.org Signed-off-by: Alexandre Ghiti --- diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 36061f4732b74..d71ea0f4466fc 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -63,7 +63,8 @@ config RISCV select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT select ARCH_STACKWALK select ARCH_SUPPORTS_ATOMIC_RMW - select ARCH_SUPPORTS_CFI_CLANG + # clang >= 17: https://github.com/llvm/llvm-project/commit/62fa708ceb027713b386c7e0efda994f8bdc27e2 + select ARCH_SUPPORTS_CFI_CLANG if CLANG_VERSION >= 170000 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE select ARCH_SUPPORTS_HUGETLBFS if MMU