From patchwork Fri Nov 22 08:00:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Markus Armbruster X-Patchwork-Id: 1199345 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="EeA5fkRC"; dkim-atps=neutral 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 ozlabs.org (Postfix) with ESMTPS id 47K8BY5XsSz9sPT for ; Fri, 22 Nov 2019 19:05:57 +1100 (AEDT) Received: from localhost ([::1]:48162 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iY3wx-0008JR-2t for incoming@patchwork.ozlabs.org; Fri, 22 Nov 2019 03:05:55 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:42019) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iY3s5-0002yK-8x for qemu-devel@nongnu.org; Fri, 22 Nov 2019 03:00:54 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iY3rz-00007h-Oo for qemu-devel@nongnu.org; Fri, 22 Nov 2019 03:00:51 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:55858 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iY3rx-00006b-PN for qemu-devel@nongnu.org; Fri, 22 Nov 2019 03:00:45 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1574409644; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=MuSq9iiujh0gUMipQQgmryW+wdqp2u+B8YzVdrLvwVo=; b=EeA5fkRCOqbU7mIqpohX+Wk8YNN0h5lD+Etd7F9n1xk2jyCjIfMrkGzYwlfiD/0FC780q0 6bjyNIfWAuwfecYlKHVD8mFBEuuirBz4n2kaBQGimoTegdiOBqMkDMULXZtHFGaubk4LRi 3GFd9Pw2fms5AcL71l/562iTX2o6MBw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-354-NrROnIlyPFGHrE8PUpNcuA-1; Fri, 22 Nov 2019 03:00:42 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5B5F1801E58; Fri, 22 Nov 2019 08:00:41 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-134.ams2.redhat.com [10.36.116.134]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 143536E713; Fri, 22 Nov 2019 08:00:41 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 8C44B11385C7; Fri, 22 Nov 2019 09:00:39 +0100 (CET) From: Markus Armbruster To: qemu-devel@nongnu.org Subject: [PATCH v3 1/2] migration: Fix incorrect integer->float conversion caught by clang Date: Fri, 22 Nov 2019 09:00:38 +0100 Message-Id: <20191122080039.12771-2-armbru@redhat.com> In-Reply-To: <20191122080039.12771-1-armbru@redhat.com> References: <20191122080039.12771-1-armbru@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: NrROnIlyPFGHrE8PUpNcuA-1 X-Mimecast-Spam-Score: 0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 205.139.110.120 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: Fangrui Song , richard.henderson@linaro.org, dgilbert@redhat.com, quintela@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Fangrui Song Clang does not like qmp_migrate_set_downtime()'s code to clamp double @value to 0..INT64_MAX: qemu/migration/migration.c:2038:24: error: implicit conversion from 'long' to 'double' changes value from 9223372036854775807 to 9223372036854775808 [-Werror,-Wimplicit-int-float-conversion] The warning will be enabled by default in clang 10. It is not available for clang <= 9. The clamp is actually useless; @value is checked to be within 0..MAX_MIGRATE_DOWNTIME_SECONDS immediately before. Delete it. While there, make the conversion from double to int64_t explicit. Signed-off-by: Fangrui Song Reviewed-by: Markus Armbruster [Patch split, commit message improved] Signed-off-by: Markus Armbruster Reviewed-by: Richard Henderson Reviewed-by: Juan Quintela Reviewed-by: Philippe Mathieu-Daudé --- migration/migration.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 354ad072fa..09b150663f 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2035,11 +2035,10 @@ void qmp_migrate_set_downtime(double value, Error **errp) } value *= 1000; /* Convert to milliseconds */ - value = MAX(0, MIN(INT64_MAX, value)); MigrateSetParameters p = { .has_downtime_limit = true, - .downtime_limit = value, + .downtime_limit = (int64_t)value, }; qmp_migrate_set_parameters(&p, errp); From patchwork Fri Nov 22 08:00:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Markus Armbruster X-Patchwork-Id: 1199344 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; 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Fri, 22 Nov 2019 03:00:42 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 70195DC23; Fri, 22 Nov 2019 08:00:41 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-134.ams2.redhat.com [10.36.116.134]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 190C976FE5; Fri, 22 Nov 2019 08:00:41 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 8F43511366CC; Fri, 22 Nov 2019 09:00:39 +0100 (CET) From: Markus Armbruster To: qemu-devel@nongnu.org Subject: [PATCH v3 2/2] util/cutils: Fix incorrect integer->float conversion caught by clang Date: Fri, 22 Nov 2019 09:00:39 +0100 Message-Id: <20191122080039.12771-3-armbru@redhat.com> In-Reply-To: <20191122080039.12771-1-armbru@redhat.com> References: <20191122080039.12771-1-armbru@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-MC-Unique: _QR7sY5NOaap47YNikMrUw-1 X-Mimecast-Spam-Score: 0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 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: Fangrui Song , richard.henderson@linaro.org, dgilbert@redhat.com, quintela@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Fangrui Song Clang does not like do_strtosz()'s code to guard against overflow: qemu/util/cutils.c:245:23: error: implicit conversion from 'unsigned long' to 'double' changes value from 18446744073709550592 to 18446744073709551616 [-Werror,-Wimplicit-int-float-conversion] The warning will be enabled by default in clang 10. It is not available for clang <= 9. val * mul >= 0xfffffffffffffc00 is indeed wrong. 0xfffffffffffffc00 is not representable exactly as double. It's half-way between the representable values 0xfffffffffffff800 and 0x10000000000000000. Which one we get is implementation-defined. Bad. We want val * mul > (the largest uint64_t exactly representable as double). That's 0xfffffffffffff800. Write it as nextafter(0x1p64, 0) with a suitable comment. Signed-off-by: Fangrui Song Reviewed-by: Markus Armbruster [Patch split, commit message improved] Signed-off-by: Markus Armbruster Reviewed-by: Richard Henderson Reviewed-by: Juan Quintela --- util/cutils.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/util/cutils.c b/util/cutils.c index fd591cadf0..77acadc70a 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -239,10 +239,12 @@ static int do_strtosz(const char *nptr, const char **end, goto out; } /* - * Values >= 0xfffffffffffffc00 overflow uint64_t after their trip - * through double (53 bits of precision). + * Values near UINT64_MAX overflow to 2**64 when converting to double + * precision. Compare against the maximum representable double precision + * value below 2**64, computed as "the next value after 2**64 (0x1p64) in + * the direction of 0". */ - if ((val * mul >= 0xfffffffffffffc00) || val < 0) { + if ((val * mul > nextafter(0x1p64, 0)) || val < 0) { retval = -ERANGE; goto out; }