From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 446CAC433E9 for ; Thu, 18 Mar 2021 19:30:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 08F9764F10 for ; Thu, 18 Mar 2021 19:30:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232920AbhCRTaD (ORCPT ); Thu, 18 Mar 2021 15:30:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35800 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230008AbhCRT3p (ORCPT ); Thu, 18 Mar 2021 15:29:45 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C835C06174A for ; Thu, 18 Mar 2021 12:29:45 -0700 (PDT) Message-Id: <20210318192819.795280387@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1616095781; 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: references:references; bh=MyrChZScikc3Vj+iBqMdUcIc5sbYRawJcbm85JMUQqg=; b=JeFfOOXrr4wTLSd56PyYMBAIzefcAU1o1J0WJA5oJQ04Q7xw4BpH7tYphZc4z8XeR6AbCM Vp4A9XEHtBc+Ysg9+kEsZ4iMG3XVtR8CsagaDbx7/5spXzlK4YZLkheAfQ1pwzCF1q/ndO i10SoVk/lpxaHTRssiqpFZlD9OeUPThQhn59ieNgvAwh1DoZxa86PBJScgDpdAyTG6COQw lQX2sPJn6K4DvGUjsQZaFiXEv2Izr43b1o7YvjWfm59A2+UZMoyNPBrgiCr7z/p6fThKsq VRahHpGJYB+RRMwTm1NFGJDbAbrYgPnFgDoG5pDMUDx+gwidyhaPuf3tXrTqcw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1616095781; 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: references:references; bh=MyrChZScikc3Vj+iBqMdUcIc5sbYRawJcbm85JMUQqg=; b=3HgKywDsBFiXcQzJ+/uMoIGv/yuspY2egZ/06mJxfCMmok3LwDmykLHvyKfaAjubNUqeoX ZVW8CHcjnXhnWjBQ== Date: Thu, 18 Mar 2021 20:26:48 +0100 From: Thomas Gleixner To: LKML Cc: x86@kernel.org, Vitaly Kuznetsov Subject: [patch 2/2] x86/vector: Add a sanity check to prevent IRQ2 allocations References: <20210318192646.868059483@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-transfer-encoding: 8-bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To prevent another incidental removal of the IRQ2 ignore logic in the IO/APIC code going unnoticed add a sanity check. Add some commentry at the other place which ignores IRQ2 while at it. Signed-off-by: Thomas Gleixner --- arch/x86/kernel/apic/vector.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -543,6 +543,14 @@ static int x86_vector_alloc_irqs(struct if ((info->flags & X86_IRQ_ALLOC_CONTIGUOUS_VECTORS) && nr_irqs > 1) return -ENOSYS; + /* + * Catch any attempt to touch the cascade interrupt on a PIC + * equipped system. + */ + if (WARN_ON_ONCE(info->flags & X86_IRQ_ALLOC_LEGACY && + virq == PIC_CASCADE_IR)) + return -EINVAL; + for (i = 0; i < nr_irqs; i++) { irqd = irq_domain_get_irq_data(domain, virq + i); BUG_ON(!irqd); @@ -745,6 +753,11 @@ void __init lapic_assign_system_vectors( /* Mark the preallocated legacy interrupts */ for (i = 0; i < nr_legacy_irqs(); i++) { + /* + * Don't touch the cascade interrupt. It's unusable + * on PIC equipped machines. See the large comment + * in the IO/APIC code. + */ if (i != PIC_CASCADE_IR) irq_matrix_assign(vector_matrix, ISA_IRQ_VECTOR(i)); }