From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 280E82117B555 for ; Mon, 22 Oct 2018 13:18:37 -0700 (PDT) Subject: [PATCH 1/9] mm/resource: return real error codes from walk failures From: Dave Hansen Date: Mon, 22 Oct 2018 13:13:19 -0700 References: <20181022201317.8558C1D8@viggo.jf.intel.com> In-Reply-To: <20181022201317.8558C1D8@viggo.jf.intel.com> Message-Id: <20181022201319.471D7B85@viggo.jf.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: linux-kernel@vger.kernel.org Cc: thomas.lendacky@amd.com, mhocko@suse.com, linux-nvdimm@lists.01.org, Dave Hansen , ying.huang@intel.com, linux-mm@kvack.org, zwisler@kernel.org, fengguang.wu@intel.com, akpm@linux-foundation.org List-ID: 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 is, 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. 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 --- b/kernel/resource.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) 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 2018-10-22 13:12:21.000930395 -0700 +++ b/kernel/resource.c 2018-10-22 13:12:21.003930395 -0700 @@ -375,7 +375,7 @@ 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)) { @@ -453,7 +453,7 @@ 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; _ _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm