From nobody Sat Nov 15 17:18:49 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=linaro.org ARC-Seal: i=1; a=rsa-sha256; t=1595608800; cv=none; d=zohomail.com; s=zohoarc; b=ClqRtvsOaxagqslXFWN0/QX9ywginwd+WvmPEVAvvrNhYEtLAnlVtj1qc2mOWbQetsj9SdoDbgRc9bob8zzlO3u5GHcxD8Qo47RRTl0KWwqQ9OFK3QyCzjO4MAHN8RUMrEOCfaRvdnHeNLYAOtIv90fFtvOg2ZMhYkAHhQbO818= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1595608800; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=GFpd1WzRdKHPdu50aGofJzb2YYZBrwx+q9wbcazemUg=; b=QHXplo0xhf1I2ykKg0p6jubW8co3NAC13HRF/zUplqZz2WJjZwfPYytA7lMz/SV0C86h5S0vZpcxtDwBT0mXxgovrS3OMWN0xKlQtsAJneSl8npmEOpD5hbQu8XPGe9HTbUe8uN9KFBpfNJbnPVpOvXXU5Ei3PpIC+NX2jlhKfo= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1595608800856415.04388810892453; Fri, 24 Jul 2020 09:40:00 -0700 (PDT) Received: from localhost ([::1]:43202 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jz0jn-0002ID-JG for importer@patchew.org; Fri, 24 Jul 2020 12:39:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54620) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jz0it-0000c2-BU for qemu-devel@nongnu.org; Fri, 24 Jul 2020 12:39:03 -0400 Received: from mail-pf1-x442.google.com ([2607:f8b0:4864:20::442]:42564) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jz0ir-0001UI-IV for qemu-devel@nongnu.org; Fri, 24 Jul 2020 12:39:03 -0400 Received: by mail-pf1-x442.google.com with SMTP id 1so5462319pfn.9 for ; Fri, 24 Jul 2020 09:39:01 -0700 (PDT) Received: from localhost.localdomain (216-160-65-90.tukw.qwest.net. [216.160.65.90]) by smtp.gmail.com with ESMTPSA id r191sm7261663pfr.181.2020.07.24.09.38.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 24 Jul 2020 09:38:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=GFpd1WzRdKHPdu50aGofJzb2YYZBrwx+q9wbcazemUg=; b=O3G1OrLbrwLrIWePvOU2kpOAGF9r2a0c9LcWLH1ACJ0irlTLltKiyua/QusVZovhGV O1zWjY+DWvFZDzJs6/5iv9ZZ5w7w2AxL+p2zY2GO5/SDitfCZSDxi1MzJSrSeGadC83x ndem/2OVIeUA/QzvGX0RdD/yUGV3ibFyrcNB/4g/ZwMg5TSZMYPMJnvHRPG5Raj75V2f b0CEFhQfVZqfC6MB1QZIU4Qf5nIfPrYxdnmJXFF5bWa6r4vn2aNfi2e/TDiTSomp7xi1 kZHR9GGwYH6UX7JmZ6rmb3AzsCv3PLWsbGPv9tyYZ6Ux6dqnLrSiRa49C+sv1PP+ZXdL 6X3Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=GFpd1WzRdKHPdu50aGofJzb2YYZBrwx+q9wbcazemUg=; b=GcjsGDtNygYLvEGVYR8Gcoqg6ftTvlulN23BRHLeJIEpPBPl/5z8VB9Y4E+VAadzaU 2CP+bd+s6DuC4L5M1nbaKSG71VCgj+3CWp+v0nw4LPLgmzkgvQy7SgPUx8W70ydNUtKE C/zdsXzjydL9BN+tbYDEGPAxogNgsTvPy608vyVdKuKF4KqanK3KuSquSnaMeQLxBQAu +3lXmpruY30cirkPz2BZiLiCMiQS9ZYnwad1jfwH33FCycvVbUT39VFBXHPMxg6sPXAa 6RtfCmFVz/VHmdP8Xs8LQJ4cinfujTbU5s4cIa8p+Ekz5hcCqr49//8vLFHsWnvx5eVx f19g== X-Gm-Message-State: AOAM532meWS7oB6LwK2DbM9s1zGQRZD4ecWAZXjEw5364gTf3hgZmVSe c8M859Eo+HTr9tHSF3nSrzKYs9YBMoc= X-Google-Smtp-Source: ABdhPJxA+PvF2ZfbD0Upm1HIXxpoyILYwd6GnvCqIwXbYOikU+NdgWCFPHhgMrOdjiWlYsb7/3umIw== X-Received: by 2002:a65:620f:: with SMTP id d15mr9034163pgv.270.1595608739240; Fri, 24 Jul 2020 09:38:59 -0700 (PDT) From: Richard Henderson To: qemu-devel@nongnu.org Subject: [PATCH 3/3] target/arm: Improve IMPDEF algorithm for IRG Date: Fri, 24 Jul 2020 09:38:53 -0700 Message-Id: <20200724163853.504655-4-richard.henderson@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200724163853.504655-1-richard.henderson@linaro.org> References: <20200724163853.504655-1-richard.henderson@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2607:f8b0:4864:20::442; envelope-from=richard.henderson@linaro.org; helo=mail-pf1-x442.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org, vincenzo.frascino@arm.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: pass (identity @linaro.org) Content-Type: text/plain; charset="utf-8" When GCR_EL1.RRND=3D=3D1, the choosing of the random value is IMPDEF, and the kernel is not expected to have set RGSR_EL1. Force a non-zero value into SEED, so that we do not continually return the same tag. Reported-by: Vincenzo Frascino Signed-off-by: Richard Henderson --- target/arm/mte_helper.c | 37 ++++++++++++++++++++++++++++++------- 1 file changed, 30 insertions(+), 7 deletions(-) diff --git a/target/arm/mte_helper.c b/target/arm/mte_helper.c index 5ea57d487a..104752041f 100644 --- a/target/arm/mte_helper.c +++ b/target/arm/mte_helper.c @@ -24,6 +24,8 @@ #include "exec/ram_addr.h" #include "exec/cpu_ldst.h" #include "exec/helper-proto.h" +#include "qapi/error.h" +#include "qemu/guest-random.h" =20 =20 static int choose_nonexcluded_tag(int tag, int offset, uint16_t exclude) @@ -211,16 +213,37 @@ static uint8_t *allocation_tag_mem(CPUARMState *env, = int ptr_mmu_idx, =20 uint64_t HELPER(irg)(CPUARMState *env, uint64_t rn, uint64_t rm) { - int rtag; - - /* - * Our IMPDEF choice for GCR_EL1.RRND=3D=3D1 is to behave as if - * GCR_EL1.RRND=3D=3D0, always producing deterministic results. - */ uint16_t exclude =3D extract32(rm | env->cp15.gcr_el1, 0, 16); + int rrnd =3D extract32(env->cp15.gcr_el1, 16, 1); int start =3D extract32(env->cp15.rgsr_el1, 0, 4); int seed =3D extract32(env->cp15.rgsr_el1, 8, 16); - int offset, i; + int offset, i, rtag; + + /* + * Our IMPDEF choice for GCR_EL1.RRND=3D=3D1 is to continue to use the + * deterministic algorithm. Except that with RRND=3D=3D1 the kernel is + * not required to have set RGSR_EL1.SEED !=3D 0, which is required for + * the deterministic algorithm to function. So we force a non-zero + * SEED for that case. + */ + if (unlikely(seed =3D=3D 0) && rrnd) { + do { + Error *err =3D NULL; + uint16_t two; + + if (qemu_guest_getrandom(&two, sizeof(two), &err) < 0) { + /* + * Failed, for unknown reasons in the crypto subsystem. + * Best we can do is log the reason and use a constant see= d. + */ + qemu_log_mask(LOG_UNIMP, "IRG: Crypto failure: %s\n", + error_get_pretty(err)); + error_free(err); + two =3D 1; + } + seed =3D two; + } while (seed =3D=3D 0); + } =20 /* RandomTag */ for (i =3D offset =3D 0; i < 4; ++i) { --=20 2.25.1