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... */ | | ^~~~~
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/00dacf8c22f065cb52efb14cd091d441... [1] Signed-off-by: Justin Stitt justinstitt@google.com --- I'm sending a similar patch 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
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Summary of potential issues: ⚠️ Could not find matching upstream commit
No upstream commit was identified. Using temporary commit for testing.
Results of testing on various branches:
| Branch | Patch Apply | Build Test | |---------------------------|-------------|------------| | origin/linux-5.15.y | Success | Success |
On Mon, Jul 28, 2025 at 02:04:24PM -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: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... */ | | ^~~~~
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/00dacf8c22f065cb52efb14cd091d441... [1] Signed-off-by: Justin Stitt justinstitt@google.com
Reviewed-by: Nathan Chancellor nathan@kernel.org
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
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