From nobody Sun Feb 8 14:07:10 2026 Received: from szxga07-in.huawei.com (szxga07-in.huawei.com [45.249.212.35]) (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 89363134CFC for ; Thu, 22 Feb 2024 14:01:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.35 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708610520; cv=none; b=qfTA3gnAFxuO4zp03iD6DmLJwxYlmqxa0PGKSI8Ep5q1aQJLnibk7ZFBZPAN9wWScpEUiR9BChw3SnxWuw1rvgsTaI55nKjVRNJprQG779Q6GCp9YWxZkpcG9qsPgeCkOD3811KQMjWKn2siTBsmmFQLzSyJ5KMgAvk9zEIRGLM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708610520; c=relaxed/simple; bh=ewA5gH0bCylPF3H13/kbdUip8+EeXFiA5OyHZLEWf6A=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=AhvgfPCGnvJy/wE1/JY7Ze0m7SgARwFVMuGLlokaUOeNP6+c6TMxhQSJMLkO1DxV5fixKguXclzhHNXMdxnC6XE5YRqpd6CWTgE02fMhZIMSKHE8SYGIOQ76zht4YbsfjjT7ndPzpCW7ORJtXXLVnLDzBrOsyluZ4xxRipJw+Oc= 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=45.249.212.35 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 [172.19.88.234]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4TgZWt4Dprz1X3F9; Thu, 22 Feb 2024 21:59:38 +0800 (CST) Received: from dggpeml500005.china.huawei.com (unknown [7.185.36.59]) by mail.maildlp.com (Postfix) with ESMTPS id C8B2114011F; Thu, 22 Feb 2024 22:01:48 +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; Thu, 22 Feb 2024 22:01:48 +0800 From: Yongqiang Liu To: CC: , , , , , , , , , , , Subject: [PATCH] arm: flush: check if the folio is reserved for IMO addresses Date: Thu, 22 Feb 2024 22:01:47 +0800 Message-ID: <20240222140147.1880357-1-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: quoted-printable X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) 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].In Some uio case we will get a crash on a system with the following memory layout: node 0: [mem 0x00000000c0a00000-0x00000000cc8fffff] node 0: [mem 0x00000000d0000000-0x00000000da1fffff] the uio layout is=EF=BC=9A0xc0900000, 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 memo= ry map alignment") Suggested-by: Mike Rapoport Signed-off-by: Yongqiang Liu --- arch/arm/mm/flush.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c index d19d140a10c7..f2b99223a0ab 100644 --- a/arch/arm/mm/flush.c +++ b/arch/arm/mm/flush.c @@ -15,6 +15,7 @@ #include #include #include +#include =20 #include "mm.h" =20 @@ -296,6 +297,9 @@ void __sync_icache_dcache(pte_t pteval) return; =20 folio =3D page_folio(pfn_to_page(pfn)); + if (test_bit(PG_reserved, &folio->flags)) + return; + if (cache_is_vipt_aliasing()) mapping =3D folio_flush_mapping(folio); else --=20 2.25.1