A new warning in Clang 22 [1] complains that @clidr passed to get_clidr_el1() is an uninitialized const pointer. get_clidr_el1() doesn't really care since it casts away the const-ness anyways -- it is a false positive.
| ../arch/arm64/kvm/sys_regs.c:2838:23: warning: variable 'clidr' is uninitialized when passed as a const pointer argument here [-Wuninitialized-const-pointer] | 2838 | get_clidr_el1(NULL, &clidr); /* Ugly... */ | | ^~~~~
This patch isn't needed for anything past 6.1 as this code section was reworked in Commit 7af0c2534f4c ("KVM: arm64: Normalize cache configuration"). Since there is no upstream equivalent, this patch just needs to be applied to 5.15.
Disable this warning for sys_regs.o with an iron fist as it doesn't make sense to waste maintainer's time or potentially break builds by backporting large changelists from 6.2+.
Cc: stable@vger.kernel.org Fixes: 7c8c5e6a9101e ("arm64: KVM: system register handling") Link: https://github.com/llvm/llvm-project/commit/00dacf8c22f065cb52efb14cd091d441... [1] Reviewed-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Justin Stitt justinstitt@google.com --- Resending this with Nathan's RB tag, an updated commit log and better recipients from checkpatch.pl.
I'm also sending a similar patch resend for 6.1. --- arch/arm64/kvm/Makefile | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 989bb5dad2c8..109cca425d3e 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -25,3 +25,6 @@ kvm-y := $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o \ vgic/vgic-its.o vgic/vgic-debug.o
kvm-$(CONFIG_HW_PERF_EVENTS) += pmu-emul.o + +# Work around a false positive Clang 22 -Wuninitialized-const-pointer warning +CFLAGS_sys_regs.o := $(call cc-disable-warning, uninitialized-const-pointer)
--- base-commit: 8bb7eca972ad531c9b149c0a51ab43a417385813 change-id: 20250728-b4-stable-disable-uninit-ptr-warn-5-15-c0c9db3df206
Best regards, -- Justin Stitt justinstitt@google.com