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=-9.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 9E619C432C1 for ; Tue, 24 Sep 2019 18:23:09 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 243B920872 for ; Tue, 24 Sep 2019 18:23:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZAYHvdXr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 243B920872 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46d8gs0VMXzDqZw for ; Wed, 25 Sep 2019 04:23:05 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=kernel.org (client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=sashal@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="ZAYHvdXr"; dkim-atps=neutral Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46d6c538HWzDqFG for ; Wed, 25 Sep 2019 02:49:41 +1000 (AEST) Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8AF9F222CA; Tue, 24 Sep 2019 16:49:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569343779; bh=g9xRuuc7DPnjhhFl6TkKWWliyfayET4dSFv/+Q/uzdc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZAYHvdXres/T1y1s47ADYyOv56oW81k32eW5CZ2kKoDi9n5cGf7wQpFOT/ayBe43p DWEXEzS04sUSpetdKkvwla4Pzn+rc4Istn36RJTS+bDu/Tw7Oi0LLReNT2v3DPJhWQ EeD92q2gunqvX1z9zkbwOs7ji/HOHh9OWf/dEvuM= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 26/50] powerpc/64s/radix: Remove redundant pfn_pte bitop, add VM_BUG_ON Date: Tue, 24 Sep 2019 12:48:23 -0400 Message-Id: <20190924164847.27780-26-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190924164847.27780-1-sashal@kernel.org> References: <20190924164847.27780-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sasha Levin , "Aneesh Kumar K . V" , linuxppc-dev@lists.ozlabs.org, Nicholas Piggin Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Nicholas Piggin [ Upstream commit 6bb25170d7a44ef0ed9677814600f0785e7421d1 ] pfn_pte is never given a pte above the addressable physical memory limit, so the masking is redundant. In case of a software bug, it is not obviously better to silently truncate the pfn than to corrupt the pte (either one will result in memory corruption or crashes), so there is no reason to add this to the fast path. Add VM_BUG_ON to catch cases where the pfn is invalid. These would catch the create_section_mapping bug fixed by a previous commit. [16885.256466] ------------[ cut here ]------------ [16885.256492] kernel BUG at arch/powerpc/include/asm/book3s/64/pgtable.h:612! cpu 0x0: Vector: 700 (Program Check) at [c0000000ee0a36d0] pc: c000000000080738: __map_kernel_page+0x248/0x6f0 lr: c000000000080ac0: __map_kernel_page+0x5d0/0x6f0 sp: c0000000ee0a3960 msr: 9000000000029033 current = 0xc0000000ec63b400 paca = 0xc0000000017f0000 irqmask: 0x03 irq_happened: 0x01 pid = 85, comm = sh kernel BUG at arch/powerpc/include/asm/book3s/64/pgtable.h:612! Linux version 5.3.0-rc1-00001-g0fe93e5f3394 enter ? for help [c0000000ee0a3a00] c000000000d37378 create_physical_mapping+0x260/0x360 [c0000000ee0a3b10] c000000000d370bc create_section_mapping+0x1c/0x3c [c0000000ee0a3b30] c000000000071f54 arch_add_memory+0x74/0x130 Signed-off-by: Nicholas Piggin Reviewed-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190724084638.24982-5-npiggin@gmail.com Signed-off-by: Sasha Levin --- arch/powerpc/include/asm/book3s/64/pgtable.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h index 855dbae6d351d..a717640b7eda4 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h @@ -629,8 +629,10 @@ static inline bool pte_access_permitted(pte_t pte, bool write) */ static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot) { - return __pte((((pte_basic_t)(pfn) << PAGE_SHIFT) & PTE_RPN_MASK) | - pgprot_val(pgprot)); + VM_BUG_ON(pfn >> (64 - PAGE_SHIFT)); + VM_BUG_ON((pfn << PAGE_SHIFT) & ~PTE_RPN_MASK); + + return __pte(((pte_basic_t)pfn << PAGE_SHIFT) | pgprot_val(pgprot)); } static inline unsigned long pte_pfn(pte_t pte) -- 2.20.1