From patchwork Mon Apr 15 06:31:10 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anshuman Khandual X-Patchwork-Id: 13629470 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 88F36C4345F for ; Mon, 15 Apr 2024 06:31:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=Q+xb0gyc5AfOAqKlVT4fjU/NjZtaZ2TgLXAHex5BxCw=; b=eHTC5CjK+hhPsC ATXbaWnp8rmIzU4SSWe3/loPymJxDhBHm8Xwlqr5DILTOJYo57XvnUXZ6q6ZyMF+ow9jeHL6yJPmY 4vE3PjKSrUuFf8ZwGoM3URtuTKVJq4Wb8IOX79M5uy+0Ft4YlYh5P/ckeg7v2o00zyrfll+GjsB83 IcipeQjpeXPvF8ELEkB1gXtnPNV9d7MEBUozf6HSWAyjLXtLMmpRFkLt6y0YhPH0PeCXiw9vMCVWG lGxHRmGnIP385on7sVUBfaZW9V7NqFdJvi0wmSjqZd2ucunfHKhR0hwYnOpZRyWi8YF4G2nt4Okoi Aznx7nvEGGp6/R/izmpg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rwFsI-000000079dB-0gwg; Mon, 15 Apr 2024 06:31:30 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rwFsE-000000079cF-2WGO for linux-arm-kernel@lists.infradead.org; Mon, 15 Apr 2024 06:31:28 +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 650B8339; Sun, 14 Apr 2024 23:31:48 -0700 (PDT) Received: from a077893.blr.arm.com (a077893.blr.arm.com [10.162.41.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id E84B03F64C; Sun, 14 Apr 2024 23:31:16 -0700 (PDT) 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, Dev Jain Subject: [PATCH] arm64/hugetlb: Fix page table walk in huge_pte_alloc() Date: Mon, 15 Apr 2024 12:01:10 +0530 Message-Id: <20240415063110.1795707-1-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-20240414_233126_825393_3763E6F4 X-CRM114-Status: GOOD ( 11.79 ) 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 Currently normal HugeTLB fault ends up crashing the kernel, as p4dp derived from p4d_offset() is an invalid address when PGTABLE_LEVEL = 5. A p4d level entry needs to be allocated when not available while walking the page table during HugeTLB faults. Let's call p4d_alloc() to allocate such entries when required instead of current p4d_offset(). Unable to handle kernel paging request at virtual address ffffffff80000000 Mem abort info: ESR = 0x0000000096000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault Data abort info: ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 swapper pgtable: 4k pages, 52-bit VAs, pgdp=0000000081da9000 [ffffffff80000000] pgd=1000000082cec003, p4d=0000000082c32003, pud=0000000000000000 Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 108 Comm: high_addr_hugep Not tainted 6.9.0-rc4 #48 Hardware name: Foundation-v8A (DT) pstate: 01402005 (nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) pc : huge_pte_alloc+0xd4/0x334 lr : hugetlb_fault+0x1b8/0xc68 sp : ffff8000833bbc20 x29: ffff8000833bbc20 x28: fff000080080cb58 x27: ffff800082a7cc58 x26: 0000000000000000 x25: fff0000800378e40 x24: fff00008008d6c60 x23: 00000000de9dbf07 x22: fff0000800378e40 x21: 0004000000000000 x20: 0004000000000000 x19: ffffffff80000000 x18: 1ffe00010011d7a1 x17: 0000000000000001 x16: ffffffffffffffff x15: 0000000000000001 x14: 0000000000000000 x13: ffff8000816120d0 x12: ffffffffffffffff x11: 0000000000000000 x10: fff00008008ebd0c x9 : 0004000000000000 x8 : 0000000000001255 x7 : fff00008003e2000 x6 : 00000000061d54b0 x5 : 0000000000001000 x4 : ffffffff80000000 x3 : 0000000000200000 x2 : 0000000000000004 x1 : 0000000080000000 x0 : 0000000000000000 Call trace: huge_pte_alloc+0xd4/0x334 hugetlb_fault+0x1b8/0xc68 handle_mm_fault+0x260/0x29c do_page_fault+0xfc/0x47c do_translation_fault+0x68/0x74 do_mem_abort+0x44/0x94 el0_da+0x2c/0x9c el0t_64_sync_handler+0x70/0xc4 el0t_64_sync+0x190/0x194 Code: aa000084 cb010084 b24c2c84 8b130c93 (f9400260) ---[ end trace 0000000000000000 ]--- 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 Fixes: a6bbf5d4d9d1 ("arm64: mm: Add definitions to support 5 levels of paging") Reported-by: Dev Jain Signed-off-by: Anshuman Khandual Acked-by: Ard Biesheuvel Acked-by: Mark Rutland --- This patch applies on v6.9-rc4 arch/arm64/mm/hugetlbpage.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index 0f0e10bb0a95..5c819459555a 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -276,7 +276,7 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, pte_t *ptep = NULL; pgdp = pgd_offset(mm, addr); - p4dp = p4d_offset(pgdp, addr); + p4dp = p4d_alloc(mm, pgdp, addr); pudp = pud_alloc(mm, p4dp, addr); if (!pudp) return NULL;