From patchwork Wed Mar 30 21:04:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Henrique Barboza X-Patchwork-Id: 12796372 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 D669CC433F5 for ; Wed, 30 Mar 2022 21:06:27 +0000 (UTC) Received: from localhost ([::1]:49520 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nZfWM-0006WF-Mb for qemu-devel@archiver.kernel.org; Wed, 30 Mar 2022 17:06:26 -0400 Received: from eggs.gnu.org ([209.51.188.92]:57358) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nZfUv-0003HE-DK; Wed, 30 Mar 2022 17:04:57 -0400 Received: from [2607:f8b0:4864:20::32e] (port=34391 helo=mail-ot1-x32e.google.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1nZfUt-0003J1-Ny; Wed, 30 Mar 2022 17:04:57 -0400 Received: by mail-ot1-x32e.google.com with SMTP id n19-20020a9d7113000000b005cd9cff76c3so15779899otj.1; Wed, 30 Mar 2022 14:04:55 -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=p//+aQh/WyFlQZ0jwYqkJQu/+QJtwDv0P3hrdxIZ2mY=; b=cvlB7n9Hfuy9YhV0YqvjCBAj39d26C7eneFkOd7V8ANZd/8cdnCkIB93zsE+f9aUxm TM4TPjW3ZjB0MAz5Y+RMHfuTCXp//jM+b8+U8/mYU9+Te72g8XIatjj5L9lpZGo4lWVA X0+RLCV00XrXTU370GGW4ostVad7qCY9wUbw92lxGIO8xjISEFeDI3k9ZbSx6958owHF IX4q33UhTU70n/cvR7artToBKM6UjK9DgkcoFj2PvL+aLhsankOovP5Ct/zZFGNbtIqA 7wv1IgGSxgHwJWwPrB3ESWdXI36njq/+TQ5w2cvSzOVAYWT3HLku7zhwba7ku0hX/QDy hptA== 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=p//+aQh/WyFlQZ0jwYqkJQu/+QJtwDv0P3hrdxIZ2mY=; b=zpNi4SQB0cqn21jYNNoMiSaVF48ujb0bY5sZ6qqYR16JQczAGlOVQA3C+ItBB6YBk8 hcUp7ER07yFjDJhY8DBmjRar2GzUrFDd8S4MOTAG41XqAl2Wb3sX4kVTeHK24YFEKGRc L1ujEf8FHCv4EsookVhlesBSgVVqh4CGKsIu17JaVDClXbG9PC7PYHkKVToTv/BTx2B0 BmwIERF+9MiBV2AhczII9q3nu7ALjUTLfpx7ewi0SsQECx9R4xsybZTl12z2W4XXxRFl 6BkQekOozHRCSp4iGsunUpV1JfSBCP1gZaQ2iFl1YztI3GhdqIHAY1ojC0jNQ1wfV+A0 UBoQ== X-Gm-Message-State: AOAM5328I3E861nRwnQJb42th3jWA01dZYjdT+iHXXEqZ4TqVZkjKN4D f06LaslT6900gT8KjeSOsirOgAx2RM4= X-Google-Smtp-Source: ABdhPJxYf8SSZK8puC/WzTsj1bRofqJfA5Q/wLVFKn5qTXlZQTaFldNFgCxX4JicjIQfpEOJ/E9wVg== X-Received: by 2002:a9d:6e89:0:b0:5b2:4c01:2210 with SMTP id a9-20020a9d6e89000000b005b24c012210mr4263910otr.85.1648674294147; Wed, 30 Mar 2022 14:04:54 -0700 (PDT) Received: from rekt.ibmuc.com ([2804:431:c7c6:abe8:ed:2c78:ab0c:7946]) by smtp.gmail.com with ESMTPSA id t19-20020a05687044d300b000de4e33171csm9988617oai.34.2022.03.30.14.04.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Mar 2022 14:04:53 -0700 (PDT) From: Daniel Henrique Barboza To: qemu-devel@nongnu.org Subject: [PATCH 1/4] target/ppc: initialize 'reg_val' in kvm_get_one_spr() Date: Wed, 30 Mar 2022 18:04:40 -0300 Message-Id: <20220330210443.597500-2-danielhb413@gmail.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220330210443.597500-1-danielhb413@gmail.com> References: <20220330210443.597500-1-danielhb413@gmail.com> MIME-Version: 1.0 X-Host-Lookup-Failed: Reverse DNS lookup failed for 2607:f8b0:4864:20::32e (failed) Received-SPF: pass client-ip=2607:f8b0:4864:20::32e; envelope-from=danielhb413@gmail.com; helo=mail-ot1-x32e.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: 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 'reg_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 'reg_val' has no impact in the logic and makes Valgrind output more bearable. Signed-off-by: Daniel Henrique Barboza --- target/ppc/kvm.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c index dc93b99189..ce1b926e8c 100644 --- a/target/ppc/kvm.c +++ b/target/ppc/kvm.c @@ -543,10 +543,12 @@ static void kvm_get_one_spr(CPUState *cs, uint64_t id, int spr) { PowerPCCPU *cpu = POWERPC_CPU(cs); CPUPPCState *env = &cpu->env; - union { + union reg_val { uint32_t u32; uint64_t u64; - } val; + }; + /* Init reg_val to avoid "uninitialised value" Valgrind warnings */ + union reg_val val = {0}; struct kvm_one_reg reg = { .id = id, .addr = (uintptr_t) &val,