Re: [PATCH 6.1.y] KVM: arm64: sys_regs: disable -Wuninitialized-const-pointer warning
From: Nathan Chancellor <nathan@kernel.org>
Date: 2025-08-06 22:26:03
Also in:
kvmarm, lkml, llvm, stable
On Mon, Jul 28, 2025 at 02:07:36PM -0700, Justin Stitt wrote:
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:2978:23: warning: variable 'clidr' is uninitialized when passed as a const pointer argument here [-Wuninitialized-const-pointer]
| 2978 | get_clidr_el1(NULL, &clidr); /* Ugly... */
| | ^~~~~
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+.
This patch isn't needed for anything past 6.1 as this code section was
reworked in Commit 7af0c2534f4c ("KVM: arm64: Normalize cache
configuration").
Cc: stable@vger.kernel.org
Fixes: 7c8c5e6a9101e ("arm64: KVM: system register handling")
Link: https://github.com/llvm/llvm-project/commit/00dacf8c22f065cb52efb14cd091d441f19b319e [1]
Signed-off-by: Justin Stitt <justinstitt@google.com>
---Yes, I think this is an appropriate way to address this for stable. Reviewed-by: Nathan Chancellor <nathan@kernel.org>
quoted hunk ↗ jump to hunk
--- arch/arm64/kvm/Makefile | 3 +++ 1 file changed, 3 insertions(+)diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 5e33c2d4645a..5fdb5331bfad 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile@@ -24,6 +24,9 @@ kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \ kvm-$(CONFIG_HW_PERF_EVENTS) += pmu-emul.o pmu.o +# Work around a false positive Clang 22 -Wuninitialized-const-pointer warning +CFLAGS_sys_regs.o := $(call cc-disable-warning, uninitialized-const-pointer) + always-y := hyp_constants.h hyp-constants.s define rule_gen_hyp_constants--- base-commit: 830b3c68c1fb1e9176028d02ef86f3cf76aa2476 change-id: 20250728-stable-disable-unit-ptr-warn-281fee82539c Best regards, -- Justin Stitt [off-list ref]