* Re: [PATCH 5.15.y RESEND] KVM: arm64: sys_regs: disable -Wuninitialized-const-pointer warning
2025-12-04 20:44 [PATCH 5.15.y RESEND] KVM: arm64: sys_regs: disable -Wuninitialized-const-pointer warning Justin Stitt
@ 2025-12-30 2:24 ` Tiffany Yang
2026-01-08 15:57 ` Patch "KVM: arm64: sys_regs: disable -Wuninitialized-const-pointer warning" has been added to the 5.10-stable tree gregkh
2026-01-08 15:58 ` Patch "KVM: arm64: sys_regs: disable -Wuninitialized-const-pointer warning" has been added to the 5.15-stable tree gregkh
2 siblings, 0 replies; 4+ messages in thread
From: Tiffany Yang @ 2025-12-30 2:24 UTC (permalink / raw)
To: Justin Stitt
Cc: Marc Zyngier, Oliver Upton, Alexandru Elisei, Joey Gouly,
Suzuki K Poulose, Catalin Marinas, Zenghui Yu, Will Deacon,
Nathan Chancellor, Christopher Covington, linux-arm-kernel,
kvmarm, linux-kernel, llvm, stable
Justin Stitt <justinstitt@google.com> writes:
> 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.
This error has also been showing up in 5.10 since KernelCI started using
clang-21.
> 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/00dacf8c22f065cb52efb14cd091d441f19b319e
> [1]
> Reviewed-by: Nathan Chancellor <nathan@kernel.org>
> Signed-off-by: Justin Stitt <justinstitt@google.com>
<snip>
Reviewed-by: Tiffany Yang <ynaffit@google.com>
--
Tiffany Y. Yang
^ permalink raw reply [flat|nested] 4+ messages in thread* Patch "KVM: arm64: sys_regs: disable -Wuninitialized-const-pointer warning" has been added to the 5.10-stable tree
2025-12-04 20:44 [PATCH 5.15.y RESEND] KVM: arm64: sys_regs: disable -Wuninitialized-const-pointer warning Justin Stitt
2025-12-30 2:24 ` Tiffany Yang
@ 2026-01-08 15:57 ` gregkh
2026-01-08 15:58 ` Patch "KVM: arm64: sys_regs: disable -Wuninitialized-const-pointer warning" has been added to the 5.15-stable tree gregkh
2 siblings, 0 replies; 4+ messages in thread
From: gregkh @ 2026-01-08 15:57 UTC (permalink / raw)
To: alexandru.elisei, catalin.marinas, cov, gregkh, joey.gouly,
justinstitt, kvmarm, linux-arm-kernel, llvm, maz, nathan,
oliver.upton, suzuki.poulose, will, yuzenghui
Cc: stable-commits
This is a note to let you know that I've just added the patch titled
KVM: arm64: sys_regs: disable -Wuninitialized-const-pointer warning
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-arm64-sys_regs-disable-wuninitialized-const-pointer-warning.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
From justinstitt@google.com Thu Jan 8 16:52:32 2026
From: Justin Stitt <justinstitt@google.com>
Date: Thu, 04 Dec 2025 12:44:48 -0800
Subject: KVM: arm64: sys_regs: disable -Wuninitialized-const-pointer warning
To: Marc Zyngier <maz@kernel.org>, Oliver Upton <oliver.upton@linux.dev>, Alexandru Elisei <alexandru.elisei@arm.com>, Joey Gouly <joey.gouly@arm.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, Zenghui Yu <yuzenghui@huawei.com>, Will Deacon <will@kernel.org>, Nathan Chancellor <nathan@kernel.org>, Christopher Covington <cov@codeaurora.org>
Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, stable@vger.kernel.org, Justin Stitt <justinstitt@google.com>
Message-ID: <20251204-b4-stable-disable-uninit-ptr-warn-5-15-v1-1-41212e2c6409@google.com>
From: Justin Stitt <justinstitt@google.com>
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/00dacf8c22f065cb52efb14cd091d441f19b319e [1]
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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>
Patches currently in stable-queue which might be from justinstitt@google.com are
queue-5.10/kvm-arm64-sys_regs-disable-wuninitialized-const-pointer-warning.patch
^ permalink raw reply related [flat|nested] 4+ messages in thread* Patch "KVM: arm64: sys_regs: disable -Wuninitialized-const-pointer warning" has been added to the 5.15-stable tree
2025-12-04 20:44 [PATCH 5.15.y RESEND] KVM: arm64: sys_regs: disable -Wuninitialized-const-pointer warning Justin Stitt
2025-12-30 2:24 ` Tiffany Yang
2026-01-08 15:57 ` Patch "KVM: arm64: sys_regs: disable -Wuninitialized-const-pointer warning" has been added to the 5.10-stable tree gregkh
@ 2026-01-08 15:58 ` gregkh
2 siblings, 0 replies; 4+ messages in thread
From: gregkh @ 2026-01-08 15:58 UTC (permalink / raw)
To: alexandru.elisei, catalin.marinas, cov, gregkh, joey.gouly,
justinstitt, kvmarm, linux-arm-kernel, llvm, maz, nathan,
oliver.upton, suzuki.poulose, will, yuzenghui
Cc: stable-commits
This is a note to let you know that I've just added the patch titled
KVM: arm64: sys_regs: disable -Wuninitialized-const-pointer warning
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-arm64-sys_regs-disable-wuninitialized-const-pointer-warning.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
From justinstitt@google.com Thu Jan 8 16:52:32 2026
From: Justin Stitt <justinstitt@google.com>
Date: Thu, 04 Dec 2025 12:44:48 -0800
Subject: KVM: arm64: sys_regs: disable -Wuninitialized-const-pointer warning
To: Marc Zyngier <maz@kernel.org>, Oliver Upton <oliver.upton@linux.dev>, Alexandru Elisei <alexandru.elisei@arm.com>, Joey Gouly <joey.gouly@arm.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, Zenghui Yu <yuzenghui@huawei.com>, Will Deacon <will@kernel.org>, Nathan Chancellor <nathan@kernel.org>, Christopher Covington <cov@codeaurora.org>
Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, stable@vger.kernel.org, Justin Stitt <justinstitt@google.com>
Message-ID: <20251204-b4-stable-disable-uninit-ptr-warn-5-15-v1-1-41212e2c6409@google.com>
From: Justin Stitt <justinstitt@google.com>
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/00dacf8c22f065cb52efb14cd091d441f19b319e [1]
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm64/kvm/Makefile | 3 +++
1 file changed, 3 insertions(+)
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -25,3 +25,6 @@ kvm-y := $(KVM)/kvm_main.o $(KVM)/coales
vgic/vgic-its.o vgic/vgic-debug.o
kvm-$(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)
Patches currently in stable-queue which might be from justinstitt@google.com are
queue-5.15/kvm-arm64-sys_regs-disable-wuninitialized-const-pointer-warning.patch
^ permalink raw reply [flat|nested] 4+ messages in thread