From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga06-in.huawei.com (szxga06-in.huawei.com [45.249.212.32]) (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 8E087133408 for ; Thu, 22 Feb 2024 14:06:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.32 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708610773; cv=none; b=JeXr2YR4muqOkfS+aeSnlhPot7OlfD6gieS0iPVZkog00JU5vZZPVVctIiHDxMame8KYpX5BbodH8YULIWc0FSlX7qrWYGgpZcXj4kRD0yiO6bR39P9K2Hsz6tuuT8luqI87cz0bqP8prDGpzTBE2fzXBNWK8kEZdY+WsqhQNgY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708610773; c=relaxed/simple; bh=JMuSVzb6yFklTV1JNBRqb15YMwdN2bK9kOexARPWUDk=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=NZvETfYiz9YTZYfgGnb+gYCiUdtl1723iOrqptCr4f4188XCoc166E/N6uvkb4zeon2gM48TkdXUVAR41IKEEPcqm8t1/P68DSTdncbCdPgo56Pn/SqFbNk5elm69vATi7zCqlUrQzQNdNYyTDCEWdpplkMCM5bzoOSNT4yMWiM= 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=45.249.212.32 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 szxga06-in.huawei.com (SkyGuard) with ESMTP id 4TgZfg0TgGz1vv03; Thu, 22 Feb 2024 22:05:31 +0800 (CST) Received: from dggpemm100001.china.huawei.com (unknown [7.185.36.93]) by mail.maildlp.com (Postfix) with ESMTPS id B565D140429; Thu, 22 Feb 2024 22:06:05 +0800 (CST) Received: from [10.174.177.243] (10.174.177.243) by dggpemm100001.china.huawei.com (7.185.36.93) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Thu, 22 Feb 2024 22:06:05 +0800 Message-ID: Date: Thu, 22 Feb 2024 22:06:04 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] arm: flush: check if the folio is reserved for IMO addresses Content-Language: en-US To: Yongqiang Liu , CC: , , , , , , , , , References: <20240222140147.1880357-1-liuyongqiang13@huawei.com> From: Kefeng Wang In-Reply-To: <20240222140147.1880357-1-liuyongqiang13@huawei.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm100001.china.huawei.com (7.185.36.93) On 2024/2/22 22:01, Yongqiang Liu wrote: > 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：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 > --- > 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 这个删掉吧然后发出去 > > #include "mm.h" > > @@ -296,6 +297,9 @@ void __sync_icache_dcache(pte_t pteval) > return; > > folio = page_folio(pfn_to_page(pfn)); > + if (test_bit(PG_reserved, &folio->flags)) > + return; > + > if (cache_is_vipt_aliasing()) > mapping = folio_flush_mapping(folio); > else