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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 456CDC001DE for ; Sun, 2 Jul 2023 19:56:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232726AbjGBT44 (ORCPT ); Sun, 2 Jul 2023 15:56:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232844AbjGBT4Q (ORCPT ); Sun, 2 Jul 2023 15:56:16 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B865749F6; Sun, 2 Jul 2023 12:54:09 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9389060C83; Sun, 2 Jul 2023 19:51:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 42A08C433C7; Sun, 2 Jul 2023 19:51:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1688327512; bh=gMT8HbJxqnGUa9ky1Z66895M020cPGk2vYGNE6AuCb8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ka2GoSaWV7s9IsZQFy4X9wDAqvRm+8IdWefHcJ/88+QI487aa0yvoH/BV5xO8O6P+ 08aAdmsvEFms2auuJrfM9bbQzTpV/sQfDHpbkq6wrFYn1IxjgTz3kMgGbVuhJA2Rrn 3qdv1JiooPepLyHjC5toLD4UcpW2GwBK6De17mbM3luoI9ohM9Uwq2y4kCAoSDyeOa 5mZYFFsj/FegY5pH/RwSXQz+WRrkVGRUuYfvuEnfjeI0foYVQT0lYb2/TdDCzPDr9k Tv97V/j17hkGUmLDC46DVcsTumgoJcfZD2/5P9sVIR9p9e/HsiCN5TKrzcZjGUAXTB JREiiLBrnWVBg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Mark Rutland , Russell King , Steve Capper , Will Deacon , Russell King , Catalin Marinas , Sasha Levin , anshuman.khandual@arm.com, wangkefeng.wang@huawei.com, quic_zhenhuah@quicinc.com, chenfeiyang@loongson.cn, bhe@redhat.com, linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 6.3 09/11] arm64: mm: fix VA-range sanity check Date: Sun, 2 Jul 2023 15:51:25 -0400 Message-Id: <20230702195127.1787911-9-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230702195127.1787911-1-sashal@kernel.org> References: <20230702195127.1787911-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.3.11 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mark Rutland [ Upstream commit ab9b4008092c86dc12497af155a0901cc1156999 ] Both create_mapping_noalloc() and update_mapping_prot() sanity-check their 'virt' parameter, but the check itself doesn't make much sense. The condition used today appears to be a historical accident. The sanity-check condition: if ((virt >= PAGE_END) && (virt < VMALLOC_START)) { [ ... warning here ... ] return; } ... can only be true for the KASAN shadow region or the module region, and there's no reason to exclude these specifically for creating and updateing mappings. When arm64 support was first upstreamed in commit: c1cc1552616d0f35 ("arm64: MMU initialisation") ... the condition was: if (virt < VMALLOC_START) { [ ... warning here ... ] return; } At the time, VMALLOC_START was the lowest kernel address, and this was checking whether 'virt' would be translated via TTBR1. Subsequently in commit: 14c127c957c1c607 ("arm64: mm: Flip kernel VA space") ... the condition was changed to: if ((virt >= VA_START) && (virt < VMALLOC_START)) { [ ... warning here ... ] return; } This appear to have been a thinko. The commit moved the linear map to the bottom of the kernel address space, with VMALLOC_START being at the halfway point. The old condition would warn for changes to the linear map below this, and at the time VA_START was the end of the linear map. Subsequently we cleaned up the naming of VA_START in commit: 77ad4ce69321abbe ("arm64: memory: rename VA_START to PAGE_END") ... keeping the erroneous condition as: if ((virt >= PAGE_END) && (virt < VMALLOC_START)) { [ ... warning here ... ] return; } Correct the condition to check against the start of the TTBR1 address space, which is currently PAGE_OFFSET. This simplifies the logic, and more clearly matches the "outside kernel range" message in the warning. Signed-off-by: Mark Rutland Cc: Russell King Cc: Steve Capper Cc: Will Deacon Reviewed-by: Russell King (Oracle) Link: https://lore.kernel.org/r/20230615102628.1052103-1-mark.rutland@arm.com Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin --- arch/arm64/mm/mmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 6f9d8898a0251..d9a7c481fb919 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -453,7 +453,7 @@ static phys_addr_t pgd_pgtable_alloc(int shift) static void __init create_mapping_noalloc(phys_addr_t phys, unsigned long virt, phys_addr_t size, pgprot_t prot) { - if ((virt >= PAGE_END) && (virt < VMALLOC_START)) { + if (virt < PAGE_OFFSET) { pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n", &phys, virt); return; @@ -480,7 +480,7 @@ void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys, static void update_mapping_prot(phys_addr_t phys, unsigned long virt, phys_addr_t size, pgprot_t prot) { - if ((virt >= PAGE_END) && (virt < VMALLOC_START)) { + if (virt < PAGE_OFFSET) { pr_warn("BUG: not updating mapping for %pa at 0x%016lx - outside kernel range\n", &phys, virt); return; -- 2.39.2