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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 14ACBC43381 for ; Mon, 25 Feb 2019 19:04:58 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 3C54A2084D for ; Mon, 25 Feb 2019 19:04:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3C54A2084D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 447WbV47y5zDqNr for ; Tue, 26 Feb 2019 06:04:54 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=none (mailfrom) smtp.mailfrom=linux.intel.com (client-ip=192.55.52.115; helo=mga14.intel.com; envelope-from=dave.hansen@linux.intel.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.intel.com Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 447WXy6HKCzDqKS for ; Tue, 26 Feb 2019 06:02:38 +1100 (AEDT) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Feb 2019 11:02:36 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,412,1544515200"; d="scan'208";a="149861256" Received: from viggo.jf.intel.com (HELO localhost.localdomain) ([10.54.77.144]) by fmsmga001.fm.intel.com with ESMTP; 25 Feb 2019 11:02:34 -0800 Subject: [PATCH 1/5] mm/resource: return real error codes from walk failures To: linux-kernel@vger.kernel.org From: Dave Hansen Date: Mon, 25 Feb 2019 10:57:30 -0800 References: <20190225185727.BCBD768C@viggo.jf.intel.com> In-Reply-To: <20190225185727.BCBD768C@viggo.jf.intel.com> Message-Id: <20190225185730.D8AA7812@viggo.jf.intel.com> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mhocko@suse.com, tiwai@suse.de, Dave Hansen , keith.busch@intel.com, linux-mm@kvack.org, paulus@samba.org, baiyaowei@cmss.chinamobile.com, zwisler@kernel.org, dave.jiang@intel.com, linux-nvdimm@lists.01.org, ying.huang@intel.com, bp@suse.de, thomas.lendacky@amd.com, jglisse@redhat.com, bhelgaas@google.com, dan.j.williams@intel.com, vishal.l.verma@intel.com, akpm@linux-foundation.org, fengguang.wu@intel.com, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Dave Hansen walk_system_ram_range() can return an error code either becuase *it* failed, or because the 'func' that it calls returned an error. The memory hotplug does the following: ret = walk_system_ram_range(..., func); if (ret) return ret; and 'ret' makes it out to userspace, eventually. The problem s, walk_system_ram_range() failues that result from *it* failing (as opposed to 'func') return -1. That leads to a very odd -EPERM (-1) return code out to userspace. Make walk_system_ram_range() return -EINVAL for internal failures to keep userspace less confused. This return code is compatible with all the callers that I audited. This changes both the generic mm/ and powerpc-specific implementations to have the same return value. Signed-off-by: Dave Hansen Reviewed-by: Bjorn Helgaas Acked-by: Michael Ellerman (powerpc) Cc: Dan Williams Cc: Dave Jiang Cc: Ross Zwisler Cc: Vishal Verma Cc: Tom Lendacky Cc: Andrew Morton Cc: Michal Hocko Cc: linux-nvdimm@lists.01.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Huang Ying Cc: Fengguang Wu Cc: Borislav Petkov Cc: Yaowei Bai Cc: Takashi Iwai Cc: Jerome Glisse Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: linuxppc-dev@lists.ozlabs.org Cc: Keith Busch --- b/arch/powerpc/mm/mem.c | 2 +- b/kernel/resource.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff -puN arch/powerpc/mm/mem.c~memory-hotplug-walk_system_ram_range-returns-neg-1 arch/powerpc/mm/mem.c --- a/arch/powerpc/mm/mem.c~memory-hotplug-walk_system_ram_range-returns-neg-1 2019-02-25 10:56:47.452908034 -0800 +++ b/arch/powerpc/mm/mem.c 2019-02-25 10:56:47.458908034 -0800 @@ -189,7 +189,7 @@ walk_system_ram_range(unsigned long star struct memblock_region *reg; unsigned long end_pfn = start_pfn + nr_pages; unsigned long tstart, tend; - int ret = -1; + int ret = -EINVAL; for_each_memblock(memory, reg) { tstart = max(start_pfn, memblock_region_memory_base_pfn(reg)); diff -puN kernel/resource.c~memory-hotplug-walk_system_ram_range-returns-neg-1 kernel/resource.c --- a/kernel/resource.c~memory-hotplug-walk_system_ram_range-returns-neg-1 2019-02-25 10:56:47.454908034 -0800 +++ b/kernel/resource.c 2019-02-25 10:56:47.459908034 -0800 @@ -382,7 +382,7 @@ static int __walk_iomem_res_desc(resourc int (*func)(struct resource *, void *)) { struct resource res; - int ret = -1; + int ret = -EINVAL; while (start < end && !find_next_iomem_res(start, end, flags, desc, first_lvl, &res)) { @@ -462,7 +462,7 @@ int walk_system_ram_range(unsigned long unsigned long flags; struct resource res; unsigned long pfn, end_pfn; - int ret = -1; + int ret = -EINVAL; start = (u64) start_pfn << PAGE_SHIFT; end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; _