From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4F6E31EA7CE; Fri, 11 Jul 2025 07:27:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752218879; cv=none; b=YdAXktf2GZ08jOmEizWz1hWvFuteV7gqifGkct/MWiomNjSQT38Huv31XTRQcMA98BDZ8JdZ57FCpX2KVQXg5EB7o63lIwzFv8maGGHRXiClfw4kez7yddF4KmPrIj0Bh4JO/jR6WUeOXCnrDoNP69JOlm/6Zj8b9W6hiBA/0gY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752218879; c=relaxed/simple; bh=1j6zpFS1DVxWS1hxIV2/OdRNBhbPf+kJqE3FRm4cKC4=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=rvpvbsq1DapEPCK/2UH3aIEHCKXFplVaM+WxwjdSdd+TP2UxYZqv6mLNW3JLyAe+JUZ1LkLe4mD36Vq4useAErbDg0FGTyChe9geU4W6jEzN9BdAPffjQDSdeGwRDJys0UMXG1hWBk61CTAhPh5heisYpJKwqQ3dCtPyEjWrvKY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=d0OLdVU4; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="d0OLdVU4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F0814C4CEED; Fri, 11 Jul 2025 07:27:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752218877; bh=1j6zpFS1DVxWS1hxIV2/OdRNBhbPf+kJqE3FRm4cKC4=; h=From:To:Cc:Subject:Date:From; b=d0OLdVU4WW5AyI7Qx0K6WV7vTsCe8RYod5bHaEglGd68ShyZuQBsiCZKJbvDq8fG5 /3rgIEMyKy/WVzx8LSE8c6JPNA9uwUr0p6mu7IKoGE7CalIEjtnquG9JmrjiXlGJde 4kGmdSSbclD4AHFyAjRqLLHVDZI35/MEDvivwPaDcZo16v1dqpKqcBLNYnuz+iU8Gz W1JiLAd+rki6nEXs4bOzc1J8ppdazvdGKhfan6USczkBV8AqEMm4ETus9uh1Uihc7n O4xSnlwpG6n9H64HA3voGAMTgvH1zLlPva4hY+BUuS/jcbsaT+Lkq0lUN2GlxzfQJg WigyTZS+XaRaQ== From: Arnd Bergmann To: Marc Zyngier , Oliver Upton , Catalin Marinas , Will Deacon Cc: Arnd Bergmann , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Mark Brown , James Morse , Sebastian Ott , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH] KVM: arm64: fix u64_replace_bits() usage Date: Fri, 11 Jul 2025 09:27:47 +0200 Message-Id: <20250711072752.2781647-1-arnd@kernel.org> X-Mailer: git-send-email 2.39.5 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Arnd Bergmann u64_replace_bits() returns a modified word but does not actually modify its argument, as pointed out by this new warning: arch/arm64/kvm/sys_regs.c: In function 'access_mdcr': arch/arm64/kvm/sys_regs.c:2654:17: error: ignoring return value of 'u64_replace_bits' declared with attribute 'warn_unused_result' [-Werror=unused-result] 2654 | u64_replace_bits(val, hpmn, MDCR_EL2_HPMN); The intention here must have been to update 'val', so do that instead. Fixes: efff9dd2fee7 ("KVM: arm64: Handle out-of-bound write to MDCR_EL2.HPMN") Signed-off-by: Arnd Bergmann --- arch/arm64/kvm/sys_regs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 33aa4f5071b8..793fb19bebd6 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2651,7 +2651,7 @@ static bool access_mdcr(struct kvm_vcpu *vcpu, */ if (hpmn > vcpu->kvm->arch.nr_pmu_counters) { hpmn = vcpu->kvm->arch.nr_pmu_counters; - u64_replace_bits(val, hpmn, MDCR_EL2_HPMN); + val = u64_replace_bits(val, hpmn, MDCR_EL2_HPMN); } __vcpu_assign_sys_reg(vcpu, MDCR_EL2, val); -- 2.39.5