From nobody Sun Apr 12 22:37:38 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=quarantine dis=none) header.from=suse.com ARC-Seal: i=1; a=rsa-sha256; t=1775650343; cv=none; d=zohomail.com; s=zohoarc; b=CSY2IwWE+1jUmOg9Cow5n01fk1ya8gjiheMGaeOmkV1IYCcv7EEYWwTGeZDc07qVU2334Y+9zBNSKuUvfTDR9Jwg2peckZIhjxTxBakwBva38Vp/BdKeHHDylYsJEb1ZkX+fgO/sCnhZxv2hODCyXEU+3pl6gHYPCxVhIPxN2XE= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1775650343; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=HCmUHnX4lfLVvQXrlBVVBQ6jAhvuU7BVpCLwZlOIldo=; b=btGa9WkjtHqBLdFfVNCX5eS/Nuc3PhlAZAeyETNHdb6YRmq/0L0CAUaQEj7nijZufPtmdOEgdVi0RkGBJR9lpZHOlQDO/1wrKep1Y4X2xCwMOtEhI9t+lZx6EBv+IMfkBBh+2wAcYJA9aMwODtYPvgFYTShO2oVgB1miXTKinU4= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=quarantine dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1775650343389314.2695097267049; Wed, 8 Apr 2026 05:12:23 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.1275905.1561577 (Exim 4.92) (envelope-from ) id 1wARlQ-0001fy-Do; Wed, 08 Apr 2026 12:12:08 +0000 Received: by outflank-mailman (output) from mailman id 1275905.1561577; Wed, 08 Apr 2026 12:12:08 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1wARlQ-0001fr-An; Wed, 08 Apr 2026 12:12:08 +0000 Received: by outflank-mailman (input) for mailman id 1275905; Wed, 08 Apr 2026 12:12:06 +0000 Received: from mx.expurgate.net ([195.190.135.10]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1wARlO-0001fd-G9 for xen-devel@lists.xenproject.org; Wed, 08 Apr 2026 12:12:06 +0000 Received: from mx.expurgate.net (helo=localhost) by mx.expurgate.net with esmtp id 1wARlN-0059zL-SN for xen-devel@lists.xenproject.org; Wed, 08 Apr 2026 14:12:05 +0200 Received: from [10.42.69.9] (helo=localhost) by localhost with ESMTP (eXpurgate MTA 0.9.1) (envelope-from ) id 69d6460a-bab6-0a2a0a5309dd-0a2a4509cb86-36 for ; Wed, 08 Apr 2026 14:12:05 +0200 Received: from [209.85.128.47] (helo=mail-wm1-f47.google.com) by tlsNG-bad1c0.mxtls.expurgate.net with ESMTPS (eXpurgate 4.56.0) (envelope-from ) id 69d64615-bf79-0a2a45090019-d155802fdcce-3 for ; Wed, 08 Apr 2026 14:12:05 +0200 Received: by mail-wm1-f47.google.com with SMTP id 5b1f17b1804b1-488ba6366a7so27390915e9.0 for ; Wed, 08 Apr 2026 05:12:05 -0700 (PDT) Received: from [10.156.60.236] (ip-037-024-206-209.um08.pools.vodafone-ip.de. [37.24.206.209]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-488c55d1347sm26922435e9.4.2026.04.08.05.12.04 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 08 Apr 2026 05:12:04 -0700 (PDT) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" Authentication-Results: eu.smtp.expurgate.cloud; dkim=pass header.s=google header.d=suse.com header.i="@suse.com" header.h="Content-Transfer-Encoding:Autocrypt:Subject:From:Cc:To:Content-Language:User-Agent:MIME-Version:Date:Message-ID" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1775650325; x=1776255125; darn=lists.xenproject.org; h=content-transfer-encoding:autocrypt:subject:from:cc:to :content-language:user-agent:mime-version:date:message-id:from:to:cc :subject:date:message-id:reply-to; bh=HCmUHnX4lfLVvQXrlBVVBQ6jAhvuU7BVpCLwZlOIldo=; b=PiPFxAmJ4nWAkdaVdhwKo3Rtp/mJoYc3lE/michp2yekHOHSw81fHk9fNou0CbcJjR eEgsi/pvETw2D1E2g1qqsv1qFibsqlg3/vZjnn61q2ReIsMYft9S8/Qo3tj+gd+bc4Sr hSQXZMvt1lfoolejDJZU6Mxgw/y4QWpknWZ1Jl3SFX0bZM869QZBSFcYZBz7vydsLPt+ Pe/FG4hrN1wIrIUux3mrToPzmh4Zx2XACKa+/dYvHaorRM2M71jKWRaeqjbWaVfrZHrg f0ssmYZi6ya89D/VLFw9d8E7pFaoUj4YIFgxQou31Y0EZv6O8fp2wIAVplu5nSDHot++ Z7VA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775650325; x=1776255125; h=content-transfer-encoding:autocrypt:subject:from:cc:to :content-language:user-agent:mime-version:date:message-id:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=HCmUHnX4lfLVvQXrlBVVBQ6jAhvuU7BVpCLwZlOIldo=; b=DTn+4FTP822uYrKV31AiWy59s9aRXacgOQMRd5M4PYlb5WHXepPm4utQ8/99j69yh3 t6Pmf9gWh+D1ycrRrlNN5McZznqWygPPwCpU5cy0GLUyFczpyLMgfSN1Ha322VKCh+8a 7oajstHIjsU6YDueXTVlmaWBOyVip2roGIYQQqDT+qA3fKBN2doA2chrmDKP0hLkNxOs koW6+8XPJKWVIb3/XK4Y6pIhmeXOnGARv9rckfd4Sa2FeFXpwRl2PjA/7LOVLWUgsu+4 f8RB5/m7FVdIRcqvEjIGmx1wioghTyvoY7/MEZWdPQ1IGhOp1DaBVsPA/mOMrer4/QGB VWmg== X-Gm-Message-State: AOJu0YzIM2h1NqhJnSFrp13xCOFX2L+aLD1XfO0dbChegIt7exAKOic6 nUQyZV5TGevm91whETZ1hsgoF4mHsIq4bINCTG6AGcDIjGHMQHJkhQlTCAy5U1HTtUfQATOpTgc fU0a1PQ== X-Gm-Gg: AeBDieu35CezkAgLKbCzlohEBX2+l6nRUTrUt6bXnUlhxXLNN76d/DkLHCGs8ZCba27 AZvKRXyJOaTCGrrZ7Q85F6/jgezDFVAYVteQsZ4KunpXO2bRIJXc+2SiVqGpxi7hpo6uqJgDUpB g3jbRTGNYbnxG6MJ7lhoicH2K3/iuCtKFib6SWym42XZtgUHyA7HqUq7ve4CYmmThQzeENB67P0 mU2IBm5+noaLL4XQEEMJfN9b4M0iheg5wInejKopn51lagKR4h3HmSLefZzojOa7hi9DbvtFLZu 07uR2nH6mo5EAP1VF5VFjaxRWBL3bI4RPb4crgXppdIMD2VOeGAlK6UMuKnAl3Ogt5SoiFVZSP7 8S4oFp9HE0gq+TVIUu2gky0sfePOI+RzlNyWKpvLigffoVUc6JJf2WgsdZGdEuNxIsZc5jkYc4E 2YJZflGJX3bpuzIRRLFzNrefhkm+qSGv2bjxnHcz/1Gs7woyBVXLCozd9HKGKh8gKyByH8gG3mI WCtvsz+lAJoTUs= X-Received: by 2002:a05:600c:1553:b0:488:acbc:b2e with SMTP id 5b1f17b1804b1-488acbc0ca8mr173907175e9.17.1775650324898; Wed, 08 Apr 2026 05:12:04 -0700 (PDT) Message-ID: Date: Wed, 8 Apr 2026 14:12:03 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US To: "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= , Teddy Astie From: Jan Beulich Subject: [PATCH v10] x86: use / "support" UDB Autocrypt: addr=jbeulich@suse.com; keydata= xsDiBFk3nEQRBADAEaSw6zC/EJkiwGPXbWtPxl2xCdSoeepS07jW8UgcHNurfHvUzogEq5xk hu507c3BarVjyWCJOylMNR98Yd8VqD9UfmX0Hb8/BrA+Hl6/DB/eqGptrf4BSRwcZQM32aZK 7Pj2XbGWIUrZrd70x1eAP9QE3P79Y2oLrsCgbZJfEwCgvz9JjGmQqQkRiTVzlZVCJYcyGGsD /0tbFCzD2h20ahe8rC1gbb3K3qk+LpBtvjBu1RY9drYk0NymiGbJWZgab6t1jM7sk2vuf0Py O9Hf9XBmK0uE9IgMaiCpc32XV9oASz6UJebwkX+zF2jG5I1BfnO9g7KlotcA/v5ClMjgo6Gl MDY4HxoSRu3i1cqqSDtVlt+AOVBJBACrZcnHAUSuCXBPy0jOlBhxPqRWv6ND4c9PH1xjQ3NP nxJuMBS8rnNg22uyfAgmBKNLpLgAGVRMZGaGoJObGf72s6TeIqKJo/LtggAS9qAUiuKVnygo 3wjfkS9A3DRO+SpU7JqWdsveeIQyeyEJ/8PTowmSQLakF+3fote9ybzd880fSmFuIEJldWxp Y2ggPGpiZXVsaWNoQHN1c2UuY29tPsJgBBMRAgAgBQJZN5xEAhsDBgsJCAcDAgQVAggDBBYC AwECHgECF4AACgkQoDSui/t3IH4J+wCfQ5jHdEjCRHj23O/5ttg9r9OIruwAn3103WUITZee e7Sbg12UgcQ5lv7SzsFNBFk3nEQQCACCuTjCjFOUdi5Nm244F+78kLghRcin/awv+IrTcIWF hUpSs1Y91iQQ7KItirz5uwCPlwejSJDQJLIS+QtJHaXDXeV6NI0Uef1hP20+y8qydDiVkv6l IreXjTb7DvksRgJNvCkWtYnlS3mYvQ9NzS9PhyALWbXnH6sIJd2O9lKS1Mrfq+y0IXCP10eS FFGg+Av3IQeFatkJAyju0PPthyTqxSI4lZYuJVPknzgaeuJv/2NccrPvmeDg6Coe7ZIeQ8Yj t0ARxu2xytAkkLCel1Lz1WLmwLstV30g80nkgZf/wr+/BXJW/oIvRlonUkxv+IbBM3dX2OV8 AmRv1ySWPTP7AAMFB/9PQK/VtlNUJvg8GXj9ootzrteGfVZVVT4XBJkfwBcpC/XcPzldjv+3 HYudvpdNK3lLujXeA5fLOH+Z/G9WBc5pFVSMocI71I8bT8lIAzreg0WvkWg5V2WZsUMlnDL9 mpwIGFhlbM3gfDMs7MPMu8YQRFVdUvtSpaAs8OFfGQ0ia3LGZcjA6Ik2+xcqscEJzNH+qh8V m5jjp28yZgaqTaRbg3M/+MTbMpicpZuqF4rnB0AQD12/3BNWDR6bmh+EkYSMcEIpQmBM51qM EKYTQGybRCjpnKHGOxG0rfFY1085mBDZCH5Kx0cl0HVJuQKC+dV2ZY5AqjcKwAxpE75MLFkr wkkEGBECAAkFAlk3nEQCGwwACgkQoDSui/t3IH7nnwCfcJWUDUFKdCsBH/E5d+0ZnMQi+G0A nAuWpQkjM1ASeQwSHEeAWPgskBQL Content-Transfer-Encoding: quoted-printable X-purgate-ID: tlsNG-bad1c0/1775650325-2ED4F152-29B1A2FA/0/0 X-purgate-type: clean X-purgate-size: 2238 X-ZohoMail-DKIM: pass (identity @suse.com) X-ZM-MESSAGEID: 1775650345750154100 Content-Type: text/plain; charset="utf-8" With opcode D6h now firmly reserved as another #UD-raising one in 64-bit mode, use that instead of the two-byte UD2 for bug frame marking. While there also make a minor adjustment to the emulator. Signed-off-by: Jan Beulich --- One of the table entries in stub_selftest() uses UD1, yet in not quite an appropriate way: The 0x90 following it (presumably meant to be a NOP) really is a ModR/M byte, requiring a displacement to follow. Wouldn't we better adjust that (e.g. using 0xcc instead)? --- v10: Shrink the actual emulator change to just a comment adjustment. Extend .byte directive commentary. v9: New. --- a/xen/arch/x86/include/asm/bug.h +++ b/xen/arch/x86/include/asm/bug.h @@ -21,7 +21,7 @@ =20 #ifndef __ASSEMBLER__ =20 -#define BUG_INSTR "ud2" +#define BUG_INSTR ".byte 0xd6" /* UDB, requiring gas 2.46 */ #define BUG_ASM_CONST "c" =20 #else /* !__ASSEMBLER__ */ @@ -37,7 +37,7 @@ .error "Invalid BUGFRAME index" .endif =20 - .L\@ud: ud2a + .L\@ud: .byte 0xd6 /* UDB, requiring gas 2.46 */ =20 .pushsection .rodata.str1, "aMS", @progbits, 1 .L\@s1: .asciz "\file_str" --- a/xen/arch/x86/traps.c +++ b/xen/arch/x86/traps.c @@ -1338,7 +1338,7 @@ void asmlinkage do_trap(struct cpu_user_ =20 void asmlinkage do_invalid_op(struct cpu_user_regs *regs) { - u8 bug_insn[2]; + uint8_t bug_insn; const void *eip =3D (const void *)regs->rip; int id; =20 @@ -1350,8 +1350,8 @@ void asmlinkage do_invalid_op(struct cpu } =20 if ( !is_active_kernel_text(regs->rip) || - copy_from_unsafe(bug_insn, eip, sizeof(bug_insn)) || - memcmp(bug_insn, "\xf\xb", sizeof(bug_insn)) ) + copy_from_unsafe(&bug_insn, eip, sizeof(bug_insn)) || + bug_insn !=3D 0xd6 /* UDB */ ) goto die; =20 id =3D do_bug_frame(regs, regs->rip); --- a/xen/arch/x86/x86_emulate/decode.c +++ b/xen/arch/x86/x86_emulate/decode.c @@ -651,7 +651,7 @@ decode_onebyte(struct x86_emulate_state case 0xce: /* into */ case 0xd4: /* aam */ case 0xd5: /* aad */ - case 0xd6: /* salc */ + case 0xd6: /* salc / udb */ s->not_64bit =3D true; break;