From patchwork Mon Dec 2 06:44:07 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anshuman Khandual X-Patchwork-Id: 13890055 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D999FD4979F for ; Mon, 2 Dec 2024 06:45:35 +0000 (UTC) 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: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:In-Reply-To:References:List-Owner; bh=u0dUzbcnpc7P5pixi8+kLQtek5TdB7ZvvvQlbpg5ADI=; b=kEL3YOcjnanI5dNYfAMa245f7O 3bVlHH6T6Kon9B/LyJoN7BVQxX2qYS5rDgNnfHQAG9MtvPc3f1CrCzxywpqpRwo5v0+tk4GM4Bb6p Uuhc7BanHulmPwy1cPbZzuOCGm8Ij5kg2zp9OGsVvKmcGEP2Hq1WZZUbevUTwArfPn2nwWv9im0X0 KGG/4RdYxAJs78ng8Lhe4s0ZibiDaSafEIjtvklCednRTPt8RRKb9/YDhz4SZ3NzCfPfcRpFVt3Cb 1hmp7ktgh6umdI8F68l2BFBt4KPvQFm/8D7Fh01xqP7nxlWRIIpJkXDM9q9KgZjvPvuYIkRWKzUEA lRgy+l4w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tI0BN-00000005DUp-0cZA; Mon, 02 Dec 2024 06:45:21 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tI0AM-00000005DMl-2S6D for linux-arm-kernel@lists.infradead.org; Mon, 02 Dec 2024 06:44:20 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7CCD4497; Sun, 1 Dec 2024 22:44:44 -0800 (PST) Received: from a077893.blr.arm.com (a077893.blr.arm.com [10.162.16.41]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 4C9D33F58B; Sun, 1 Dec 2024 22:44:13 -0800 (PST) From: Anshuman Khandual To: linux-arm-kernel@lists.infradead.org Cc: Anshuman Khandual , Catalin Marinas , Will Deacon , Ard Biesheuvel , Ryan Roberts , Mark Rutland , linux-kernel@vger.kernel.org Subject: [PATCH] arm64/mm: Ensure adequate HUGE_MAX_HSTATE Date: Mon, 2 Dec 2024 12:14:07 +0530 Message-Id: <20241202064407.53807-1-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241201_224418_668828_5E376219 X-CRM114-Status: UNSURE ( 8.39 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org This asserts that HUGE_MAX_HSTATE is sufficient enough preventing potential hugetlb_max_hstate runtime overflow in hugetlb_add_hstate() thus triggering a BUG_ON() there after. Cc: Catalin Marinas Cc: Will Deacon Cc: Ard Biesheuvel Cc: Ryan Roberts Cc: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual Reviewed-by: Ryan Roberts --- This patch applies on v6.13-rc1 arch/arm64/mm/hugetlbpage.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index 3215adf48a1b..98a2a0e64e25 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -519,6 +519,18 @@ pte_t huge_ptep_clear_flush(struct vm_area_struct *vma, static int __init hugetlbpage_init(void) { + /* + * HugeTLB pages are supported on maximum four page table + * levels (PUD, CONT PMD, PMD, CONT PTE) for a given base + * page size, corresponding to hugetlb_add_hstate() calls + * here. + * + * HUGE_MAX_HSTATE should at least match maximum supported + * HugeTLB page sizes on the platform. Any new addition to + * supported HugeTLB page sizes will also require changing + * HUGE_MAX_HSTATE as well. + */ + BUILD_BUG_ON(HUGE_MAX_HSTATE < 4); if (pud_sect_supported()) hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);