From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9A401C433EF for ; Thu, 31 Mar 2022 00:27:18 +0000 (UTC) Received: from localhost ([::1]:49028 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nZiej-0005Lm-LM for qemu-devel@archiver.kernel.org; Wed, 30 Mar 2022 20:27:17 -0400 Received: from eggs.gnu.org ([209.51.188.92]:37038) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nZiVW-00064g-Uc; Wed, 30 Mar 2022 20:17:48 -0400 Received: from [2001:4860:4864:20::34] (port=39327 helo=mail-oa1-x34.google.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1nZiVV-000304-EJ; Wed, 30 Mar 2022 20:17:46 -0400 Received: by mail-oa1-x34.google.com with SMTP id 586e51a60fabf-deb9295679so16503565fac.6; Wed, 30 Mar 2022 17:17:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=sOivFOrFSTEw7stIbfEnO86R22xeQdY78hcGuIajqB0=; b=WGkkchYftdejXjUKEFxSUX/Lf6SDTnx3slCandQtZpC7ptIib2cbGgWVPPbp84LMqP 0tRZCb3EHZ3kYSx19yriOtfGwKS/cSQPy4YCjT1JDZWlMyfkavJW/jMjrcfMhTO3JTgd dnIgZ9p41ItUKzf4WDxFvS4ASt3IKWsg2fv2lB4ISOJCkhw4MxSGlqcA+0F+WtBYCJLo Lqge1lWGOP+PnWGwGjNTR0fvijc7gozcUtP8jVfvVoJ5hZx4eISqedRZ4xl+mOhlIH/I roU83AgrXAibFuyN89dCK/d5Zt/GZYb48ao0cfZjX9p+jTAxbfBY6rR618JxHNKIdQc7 9BPA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=sOivFOrFSTEw7stIbfEnO86R22xeQdY78hcGuIajqB0=; b=I1GMgOXha0tP2K+G2ToTq8pt3V0urWu3dsH+/kCwJq9jUmVdSoGKSUARq+VTQXE4s3 9G6t0DFeZc8yHsarprFhwj8UINQ31hUyPQyh/UE3DVE6BjvbuKUVOmRRzR09C+Mnneag irvx5+HGP38zsScd8JJR6ty6+i8T9gpo4EAo4dJ82opW6bwwBneJ7tfTOT81cmVkQEFr RInPjIFky9JxX6awGPb46mWvSdnuMsx0wisjS7fWcJ0gkMnoMvBUtYAS7eUfGmxEbkrj CMagY+vKibjhF2ue7BBGH5U3CcTJf9YJ6DSPpTjA2HAW9xlUfOzzrj4lRVxohG3QnDj+ sLyg== X-Gm-Message-State: AOAM531SGfageFMA3SHWM9eQmmnjAViopwPigiS32OWuP+1eWjfqXQRU MMNkSkRv4Fif2gOybD7f1PbuAW8dVYY= X-Google-Smtp-Source: ABdhPJxZEUUWqZkTd6YI9/pIhgQAx3GauLDNqC+in6H0cArrH1miTC3ec4VSJCbpDYBy02bpe8aFRg== X-Received: by 2002:a05:6870:b02a:b0:de:aa91:898c with SMTP id y42-20020a056870b02a00b000deaa91898cmr1350236oae.25.1648685863400; Wed, 30 Mar 2022 17:17:43 -0700 (PDT) Received: from rekt.ibmuc.com ([2804:431:c7c6:abe8:ed:2c78:ab0c:7946]) by smtp.gmail.com with ESMTPSA id j126-20020acab984000000b002da77222b7dsm11149190oif.22.2022.03.30.17.17.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Mar 2022 17:17:43 -0700 (PDT) From: Daniel Henrique Barboza To: qemu-devel@nongnu.org Subject: [PATCH v2 1/4] target/ppc: initialize 'val' union in kvm_get_one_spr() Date: Wed, 30 Mar 2022 21:17:14 -0300 Message-Id: <20220331001717.616938-2-danielhb413@gmail.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220331001717.616938-1-danielhb413@gmail.com> References: <20220331001717.616938-1-danielhb413@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Host-Lookup-Failed: Reverse DNS lookup failed for 2001:4860:4864:20::34 (failed) Received-SPF: pass client-ip=2001:4860:4864:20::34; envelope-from=danielhb413@gmail.com; helo=mail-oa1-x34.google.com X-Spam_score_int: -3 X-Spam_score: -0.4 X-Spam_bar: / X-Spam_report: (-0.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, PDS_HP_HELO_NORDNS=0.659, RCVD_IN_DNSWL_NONE=-0.0001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Daniel Henrique Barboza , qemu-ppc@nongnu.org, clg@kaod.org, david@gibson.dropbear.id.au Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Valgrind isn't convinced that we are initializing the values we assign to env->spr[spr] because it doesn't understand that the 'val' union is being written by the kvm_vcpu_ioctl() that follows (via struct kvm_one_reg). This results in Valgrind complaining about uninitialized values every time we use env->spr in a conditional, like this instance: ==707578== Thread 1: ==707578== Conditional jump or move depends on uninitialised value(s) ==707578== at 0xA10A40: hreg_compute_hflags_value (helper_regs.c:106) ==707578== by 0xA10C9F: hreg_compute_hflags (helper_regs.c:173) ==707578== by 0xA110F7: hreg_store_msr (helper_regs.c:262) ==707578== by 0xA051A3: ppc_cpu_reset (cpu_init.c:7168) ==707578== by 0xD4730F: device_transitional_reset (qdev.c:799) ==707578== by 0xD4A11B: resettable_phase_hold (resettable.c:182) ==707578== by 0xD49A77: resettable_assert_reset (resettable.c:60) ==707578== by 0xD4994B: resettable_reset (resettable.c:45) ==707578== by 0xD458BB: device_cold_reset (qdev.c:296) ==707578== by 0x48FBC7: cpu_reset (cpu-common.c:114) ==707578== by 0x97B5EB: spapr_reset_vcpu (spapr_cpu_core.c:38) ==707578== by 0x97BABB: spapr_cpu_core_reset (spapr_cpu_core.c:209) ==707578== Uninitialised value was created by a stack allocation ==707578== at 0xB11F08: kvm_get_one_spr (kvm.c:543) Initializing 'val' has no impact in the logic and makes Valgrind output more bearable. Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Daniel Henrique Barboza --- target/ppc/kvm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c index dc93b99189..858866ecd4 100644 --- a/target/ppc/kvm.c +++ b/target/ppc/kvm.c @@ -543,10 +543,11 @@ static void kvm_get_one_spr(CPUState *cs, uint64_t id, int spr) { PowerPCCPU *cpu = POWERPC_CPU(cs); CPUPPCState *env = &cpu->env; + /* Init 'val' to avoid "uninitialised value" Valgrind warnings */ union { uint32_t u32; uint64_t u64; - } val; + } val = { }; struct kvm_one_reg reg = { .id = id, .addr = (uintptr_t) &val, -- 2.35.1