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=-14.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 BB4EBC4338F for ; Mon, 23 Aug 2021 13:15:05 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 80E486126A for ; Mon, 23 Aug 2021 13:15:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 80E486126A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Knd504GbKoS1bkqiTblNyEq36iGBbVhKZTpKbFlA9Gc=; b=KDTcRfYEQM8Ddb HALP2E+rd3j9XBu3M69E6/EV8CwlpOIq7CjeyjsdQxyDpMGAUF50uNijdLdBS0zH0kJn6/5sR/oys FUSI877L8WOK+TMCLXW410Rh/VH8ObdCJxSFUzdTTQNhuV2YGlcLJvRlRrrP+Sc6Xp1uE91bCam5b 2p6tqnRQqQ4oPDfjKXTeIQ6SnSJZhDYd0lW6Wb+Ed8HW+Dln4pjaSIp2KWzEcUvoh0/3exjBtINjy wF9jEjQrdGAJr2TUPBYxx/QNbdaKaiAV97ma8bAv10ThLZ6Mr13aj53imHYJA0jpDBO0qffNTSixz ZD4YDt15QNFPKzHIGafA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mI9kn-00GyaC-F6; Mon, 23 Aug 2021 13:12:43 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mI9iN-00GxEd-IV; Mon, 23 Aug 2021 13:10:15 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 780CB6124B; Mon, 23 Aug 2021 13:09:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629724200; bh=18IORdqVvusrH0Fj0VVDXtKaaRMxUkPef6MJrsmm2qg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Zr/Om5YQvfTbx5iZSQxSvUT2T4TP0mok/H3UYcEwfBFV4uY7Wkhaa91+Q3D7RnEJr Q6q7RTdllb5TzFks6JcP2UE0M+/ejY3Qg+bxzd/ZOSxsfJnZ3VNzlKaTpW+rmufNLE D+ELrwjJX6EgXuse3vsn4/6mIUzwGzZ5UQR26icKafYCEyYmti8/9zcdo/pBzLhuT+ /Wa/AbHAnL34jRH/QzcoCyu72OfTvH8ky4A5Lrpk+M63+F6UUnTVIsu3XqLRGB2zoC NVQ7i1fp4Z2AC15e5q3E2MyAF+qjJSrq6CfOnw15O2cm+S7DTPyA7fzDAEO4FGIbQv 44kKLojONqI8Q== Date: Mon, 23 Aug 2021 16:09:47 +0300 From: Mike Rapoport To: Geert Uytterhoeven Cc: Rob Herring , Russell King , Nicolas Pitre , Ard Biesheuvel , Linus Walleij , Catalin Marinas , Will Deacon , Thomas Bogendoerfer , Nick Kossifidis , Paul Walmsley , Palmer Dabbelt , Albert Ou , Frank Rowand , Dave Young , Baoquan He , Vivek Goyal , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Linux ARM , "open list:BROADCOM NVRAM DRIVER" , linux-riscv , kexec@lists.infradead.org, Linux-Renesas , Linux Kernel Mailing List Subject: Re: [PATCH v5 1/9] MIPS: Avoid future duplicate elf core header reservation Message-ID: References: <92b6718f5618d5469f67b48fbea189cca0c12f4b.1628670468.git.geert+renesas@glider.be> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210823_061011_688896_E4504756 X-CRM114-Status: GOOD ( 40.47 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Aug 23, 2021 at 12:17:50PM +0200, Geert Uytterhoeven wrote: > Hi Mike, > > On Mon, Aug 16, 2021 at 7:52 AM Mike Rapoport wrote: > > On Wed, Aug 11, 2021 at 10:50:59AM +0200, Geert Uytterhoeven wrote: > > > Prepare for early_init_fdt_scan_reserved_mem() reserving the memory > > > occupied by an elf core header described in the device tree. > > > As arch_mem_init() calls early_init_fdt_scan_reserved_mem() before > > > mips_reserve_vmcore(), the latter needs to check if the memory has > > > already been reserved before. > > > > Doing memblock_reserve() for the same region is usually fine, did you > > encounter any issues without this patch? > > Does it also work if the same region is part of an earlier larger > reservation? I am no memblock expert, so I don't know. > I didn't run into any issues, as my MIPS platform is non-DT, but I > assume arch/arm64/mm/init.c:reserve_elfcorehdr() had the check for > a reason. The memory will be reserved regardless of the earlier reservation, the issue may appear when the reservations are made for different purpose. E.g. if there was crash kernel allocation before the reservation of elfcorehdr. The check in such case will prevent the second reservation, but, at least in arch/arm64/mm/init.c:reserve_elfcorehdr() it does not seem to prevent different users of the overlapping regions to step on each others toes. Moreover, arm64::reserve_elfcorehdr() seems buggy to me, because of there is only a partial overlap of the elfcorehdr with the previous reservation, the non-overlapping part of elfcorehdr won't get reserved at all. > Thanks! > > > > > > Note that mips_reserve_vmcore() cannot just be removed, as not all MIPS > > > systems use DT. > > > > > > Signed-off-by: Geert Uytterhoeven > > > --- > > > v5: > > > - New. > > > --- > > > arch/mips/kernel/setup.c | 3 ++- > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c > > > index 23a140327a0bac1b..4693add05743d78b 100644 > > > --- a/arch/mips/kernel/setup.c > > > +++ b/arch/mips/kernel/setup.c > > > @@ -429,7 +429,8 @@ static void __init mips_reserve_vmcore(void) > > > pr_info("Reserving %ldKB of memory at %ldKB for kdump\n", > > > (unsigned long)elfcorehdr_size >> 10, (unsigned long)elfcorehdr_addr >> 10); > > > > > > - memblock_reserve(elfcorehdr_addr, elfcorehdr_size); > > > + if (!memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size) > > > + memblock_reserve(elfcorehdr_addr, elfcorehdr_size); > > > #endif > > > } > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds -- Sincerely yours, Mike. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel