From nobody Sun Oct 26 01:42:40 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1515520219424713.1644038804744; Tue, 9 Jan 2018 09:50:19 -0800 (PST) Received: from localhost ([::1]:37177 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eYy2Q-0000xc-8h for importer@patchew.org; Tue, 09 Jan 2018 12:50:14 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42735) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eYy0I-0008N8-Uu for qemu-devel@nongnu.org; Tue, 09 Jan 2018 12:48:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eYy0E-0008Ct-2z for qemu-devel@nongnu.org; Tue, 09 Jan 2018 12:48:03 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35484) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eYy0D-0008CA-Px for qemu-devel@nongnu.org; Tue, 09 Jan 2018 12:47:58 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4B0153C92 for ; Tue, 9 Jan 2018 17:47:56 +0000 (UTC) Received: from localhost (ovpn-116-66.gru2.redhat.com [10.97.116.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id D4D3A5D9C6; Tue, 9 Jan 2018 17:47:55 +0000 (UTC) Date: Tue, 9 Jan 2018 15:47:54 -0200 From: Eduardo Habkost To: qemu-devel@nongnu.org Message-ID: <20180109174754.GR6646@localhost.localdomain> References: <20180109154519.25634-1-ehabkost@redhat.com> <20180109154519.25634-2-ehabkost@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20180109154519.25634-2-ehabkost@redhat.com> X-Fnord: you can see the fnord User-Agent: Mutt/1.9.1 (2017-09-22) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Tue, 09 Jan 2018 17:47:56 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH] fixup! i386: Change X86CPUDefinition::model_id to const char* X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , "Dr. David Alan Gilbert" Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" On Tue, Jan 09, 2018 at 01:45:13PM -0200, Eduardo Habkost wrote: > It is valid to have a 48-character model ID on CPUID, however the > definition of X86CPUDefinition::model_id is char[48], which can > make the compiler drop the null terminator from the string. >=20 > If a CPU model happens to have 48 bytes on model_id, "-cpu help" > will print garbage and the object_property_set_str() call at > x86_cpu_load_def() will read data outside the model_id array. >=20 > We could increase the array size to 49, but this would mean the > compiler would not issue a warning if a 49-char string is used by > mistake for model_id. >=20 > To make things simpler, simply change model_id to be const char*, > and validate the string length using an assert() on > x86_cpu_cpudef_class_init. >=20 > Reported-by: "Dr. David Alan Gilbert" > Signed-off-by: Eduardo Habkost Oops, this patch makes 486, pentium, pentium2, pentium3 and athlon crash because they don't have model_id explicitly set. Fixup: * Set model_id to "" explicitly on 486, pentium* and athlon (fix crash) * Change assert() to ensure model_id is not NULL * Move assert() to x86_register_cpudef_type() (closer to existing assert() that validates CPUID_EXT2_AMD_ALIASES) --- target/i386/cpu.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index ad79fbb111..170c0ecd43 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -939,6 +939,7 @@ static X86CPUDefinition builtin_x86_defs[] =3D { .features[FEAT_1_EDX] =3D I486_FEATURES, .xlevel =3D 0, + .model_id =3D "", }, { .name =3D "pentium", @@ -950,6 +951,7 @@ static X86CPUDefinition builtin_x86_defs[] =3D { .features[FEAT_1_EDX] =3D PENTIUM_FEATURES, .xlevel =3D 0, + .model_id =3D "", }, { .name =3D "pentium2", @@ -961,6 +963,7 @@ static X86CPUDefinition builtin_x86_defs[] =3D { .features[FEAT_1_EDX] =3D PENTIUM2_FEATURES, .xlevel =3D 0, + .model_id =3D "", }, { .name =3D "pentium3", @@ -972,6 +975,7 @@ static X86CPUDefinition builtin_x86_defs[] =3D { .features[FEAT_1_EDX] =3D PENTIUM3_FEATURES, .xlevel =3D 0, + .model_id =3D "", }, { .name =3D "athlon", @@ -3160,9 +3164,6 @@ static void x86_cpu_cpudef_class_init(ObjectClass *oc= , void *data) X86CPUDefinition *cpudef =3D data; X86CPUClass *xcc =3D X86_CPU_CLASS(oc); =20 - /* catch mistakes instead of silently truncating model_id when too lon= g */ - assert(!cpudef->model_id || strlen(cpudef->model_id) <=3D 48); - xcc->cpu_def =3D cpudef; xcc->migration_safe =3D true; } @@ -3181,6 +3182,9 @@ static void x86_register_cpudef_type(X86CPUDefinition= *def) * they shouldn't be set on the CPU model table. */ assert(!(def->features[FEAT_8000_0001_EDX] & CPUID_EXT2_AMD_ALIASES)); + /* catch mistakes instead of silently truncating model_id when too lon= g */ + assert(def->model_id && strlen(def->model_id) <=3D 48); + =20 type_register(&ti); g_free(typename); --=20 2.14.3 --=20 Eduardo