From patchwork Wed Jun 12 16:41:05 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Berg X-Patchwork-Id: 1947032 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=srJ/bKJQ; dkim=fail reason="signature verification failed" (2048-bit key; secure) header.d=sipsolutions.net header.i=@sipsolutions.net header.a=rsa-sha256 header.s=mail header.b=x4OhydiY; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.infradead.org (client-ip=2607:7c80:54:3::133; helo=bombadil.infradead.org; envelope-from=linux-um-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org; receiver=patchwork.ozlabs.org) Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4Vzrsm4yMVz20Wq for ; Thu, 13 Jun 2024 02:41:47 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=mVdDozQhgLCHWTGkIS279cpqPxFfjKVFZDQpKU4sKrQ=; b=srJ/bKJQC5SGThIM48xj6z1jLl OkrEnGgso5XJ2KOopTrxitxXHVY1y0bEUyy9NJV5mFUgIpkMj1sFWX0xt8hoBZEL+OEmwo833z0lg oUdsAEA9zuTvdeMT/htdsq4iKJZjGrTsVSoqcn5xSohyXzmN3Nny8fz+YEUZoTu0UXQIfY3E+wHtm BQyHIZcSFues131pUBKqU0mnlZTIIBWShss5h/i5RfN2NU2zIENsWJQabN6nLI1CZhL957j1nXUJP zzIXJhdhs0oDWKLj4aGeLUlLLaclDjAwif8GAFZCAgx1aT81JW/3rgTc2a8CGIq1B3GvBwlQCUct2 zwVLBXwQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sHR2f-0000000DPvX-2S8t; Wed, 12 Jun 2024 16:41:45 +0000 Received: from s3.sipsolutions.net ([2a01:4f8:242:246e::2] helo=sipsolutions.net) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sHR2a-0000000DPsW-0FfE for linux-um@lists.infradead.org; Wed, 12 Jun 2024 16:41:44 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Content-Type:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=mVdDozQhgLCHWTGkIS279cpqPxFfjKVFZDQpKU4sKrQ=; t=1718210499; x=1719420099; b=x4OhydiYL+JCFZTUOxM5XgoyqHeB5PZ9dPMQ/3TTARtJw+J vfOn9Qc9XCi6g8FbYlVfIXE0HCQbEfocgeksvqBcswoW1Zjz+RZam+t6Mi9fFLwHUJ3A+9HGzXeBL mlPO3bQpyaZz+rTx0HjM3I/h+sPHAIMj3SnjibWFqrovaIdGPvZ4cpw8DVYoM/sM6X9oyvZ2l++LX 15Qpnl8ZdvmOTyypyNeQpjJa41X/VROdjWBZoowJB3mRDiNnaJzpe1DeLiR7xEpeKyEw6EB/x01pw 9/bUpskkn1azZTEqLcM9cpmomDJ7J0sw0mFrv7A/yXMtT58k478cyTGyD1G4rSTg==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.97) (envelope-from ) id 1sHR2X-0000000AUQy-2brp; Wed, 12 Jun 2024 18:41:38 +0200 From: benjamin@sipsolutions.net To: linux-um@lists.infradead.org Cc: Benjamin Berg Subject: [PATCH v4 2/5] um: Limit TASK_SIZE to the addressable range Date: Wed, 12 Jun 2024 18:41:05 +0200 Message-ID: <20240612164108.1742106-3-benjamin@sipsolutions.net> X-Mailer: git-send-email 2.45.1 In-Reply-To: <20240612164108.1742106-1-benjamin@sipsolutions.net> References: <20240612164108.1742106-1-benjamin@sipsolutions.net> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240612_094140_144075_16390F45 X-CRM114-Status: GOOD ( 10.06 ) X-Spam-Score: -0.2 (/) X-Spam-Report: Spam detection software, running on the system "bombadil.infradead.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: From: Benjamin Berg We may have a TASK_SIZE from the host that is bigger than UML is able to address with a three-level pagetable. Guard against that by clipping the maximum TASK_SIZE to the maximum addressable area. 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X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org From: Benjamin Berg We may have a TASK_SIZE from the host that is bigger than UML is able to address with a three-level pagetable. Guard against that by clipping the maximum TASK_SIZE to the maximum addressable area. Signed-off-by: Benjamin Berg --- arch/um/kernel/um_arch.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c index 0d8b1a73cd5b..5ab1a92b6bf7 100644 --- a/arch/um/kernel/um_arch.c +++ b/arch/um/kernel/um_arch.c @@ -337,11 +337,16 @@ int __init linux_main(int argc, char **argv) stub_start -= PAGE_SIZE; host_task_size = stub_start; + /* Limit TASK_SIZE to what is addressable by the page table */ + task_size = host_task_size; + if (task_size > PTRS_PER_PGD * PGDIR_SIZE) + task_size = PTRS_PER_PGD * PGDIR_SIZE; + /* * TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps * out */ - task_size = host_task_size & PGDIR_MASK; + task_size = task_size & PGDIR_MASK; /* OS sanity checks that need to happen before the kernel runs */ os_early_checks();