From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga04-in.huawei.com (szxga04-in.huawei.com [45.249.212.190]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D11FA1401D for ; Fri, 23 Feb 2024 06:36:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.190 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708670176; cv=none; b=p0tT+sVkejmY6g1cdf86IPHV4nFNHICGnqnHGe3bsDxtxznmxEqntU5P2+eOjx3uDhD98aU/CAYkQKmJ3vwAN2Qgv3BNl3eir2DIGbe45o71GgbewWtdmatAg6xh4rqexs8ufijciv/t3AEbNkJhfjq2PnKGXH9mUlOXwPdD2ic= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708670176; c=relaxed/simple; bh=q8pNuWaa5hgVcuh7dvNYS+X6QeCBAHKqdX/eWVAD+oQ=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=UnNrGQpMwzw/ImXD2MHX3hstGEq14QPvzO4aY8SqEQid1GMjxIMonWfEZVjPZMMjLtgRzREPPSZN9Gvv4Z+VjjPsqnsq2VJ5T3aLs05vZGIquUufku7gGmQ606IQMGvMPYDuuu5xMR7c+W7OH1eNxrHn1ehwqVOB14r/5uBxK0o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.190 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.88.214]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4Th0bC23Vqz2BdKl; Fri, 23 Feb 2024 14:33:59 +0800 (CST) Received: from dggpeml500005.china.huawei.com (unknown [7.185.36.59]) by mail.maildlp.com (Postfix) with ESMTPS id C195B1A016B; Fri, 23 Feb 2024 14:36:09 +0800 (CST) Received: from huawei.com (10.175.112.125) by dggpeml500005.china.huawei.com (7.185.36.59) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Fri, 23 Feb 2024 14:36:09 +0800 From: Yongqiang Liu To: CC: , , , , , , , , , , , Subject: [PATCH v2] arm: flush: check if the folio is reserved for no-mapping addresses Date: Fri, 23 Feb 2024 14:36:08 +0800 Message-ID: <20240223063608.2605736-1-liuyongqiang13@huawei.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpeml500005.china.huawei.com (7.185.36.59) Since commit a4d5613c4dc6 ("arm: extend pfn_valid to take into account freed memory map alignment") changes the semantics of pfn_valid() to check presence of the memory map for a PFN. A valid page for an address which is reserved but not mapped by the kernel[1], the system crashed during some uio test with the following memory layout: node 0: [mem 0x00000000c0a00000-0x00000000cc8fffff] node 0: [mem 0x00000000d0000000-0x00000000da1fffff] the uio layout is：0xc0900000, 0x100000 the crash backtrace like: Unable to handle kernel paging request at virtual address bff00000 [...] CPU: 1 PID: 465 Comm: startapp.bin Tainted: G O 5.10.0 #1 Hardware name: Generic DT based system PC is at b15_flush_kern_dcache_area+0x24/0x3c LR is at __sync_icache_dcache+0x6c/0x98 [...] (b15_flush_kern_dcache_area) from (__sync_icache_dcache+0x6c/0x98) (__sync_icache_dcache) from (set_pte_at+0x28/0x54) (set_pte_at) from (remap_pfn_range+0x1a0/0x274) (remap_pfn_range) from (uio_mmap+0x184/0x1b8 [uio]) (uio_mmap [uio]) from (__mmap_region+0x264/0x5f4) (__mmap_region) from (__do_mmap_mm+0x3ec/0x440) (__do_mmap_mm) from (do_mmap+0x50/0x58) (do_mmap) from (vm_mmap_pgoff+0xfc/0x188) (vm_mmap_pgoff) from (ksys_mmap_pgoff+0xac/0xc4) (ksys_mmap_pgoff) from (ret_fast_syscall+0x0/0x5c) Code: e0801001 e2423001 e1c00003 f57ff04f (ee070f3e) ---[ end trace 09cf0734c3805d52 ]--- Kernel panic - not syncing: Fatal exception So check if PG_reserved was set to solve this issue. [1]: https://lore.kernel.org/lkml/Zbtdue57RO0QScJM@linux.ibm.com/ Fixes: a4d5613c4dc6 ("arm: extend pfn_valid to take into account freed memory map alignment") Suggested-by: Mike Rapoport Signed-off-by: Yongqiang Liu --- v1 -> v2 - Improve commit message - Use helpers instead of PG_reserved - drop the unnecessary include headers arch/arm/mm/flush.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c index d19d140a10c7..0749cf8a6637 100644 --- a/arch/arm/mm/flush.c +++ b/arch/arm/mm/flush.c @@ -296,6 +296,9 @@ void __sync_icache_dcache(pte_t pteval) return; folio = page_folio(pfn_to_page(pfn)); + if (folio_test_reserved(folio)) + return; + if (cache_is_vipt_aliasing()) mapping = folio_flush_mapping(folio); else -- 2.25.1