From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Kroah-Hartman Subject: [PATCH 5.0 057/246] mm/resource: Return real error codes from walk failures Date: Thu, 4 Apr 2019 10:45:57 +0200 Message-ID: <20190404084621.174666333@linuxfoundation.org> References: <20190404084619.236418459@linuxfoundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190404084619.236418459-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Michal Hocko , Takashi Iwai , Benjamin Herrenschmidt , Dave Hansen , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Paul Mackerras , Yaowei Bai , Ross Zwisler , Sasha Levin , linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, Huang Ying , Borislav Petkov , Tom Lendacky , Jerome Glisse , Bjorn Helgaas , Greg Kroah-Hartman , stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Michael Ellerman , Andrew Morton , Fengguang Wu , linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org List-Id: linux-nvdimm@lists.01.org 5.0-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 5cd401ace914dc68556c6d2fcae0c349444d5f86 ] 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. 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-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.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-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Cc: Keith Busch Signed-off-by: Dan Williams Signed-off-by: Sasha Levin --- kernel/resource.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index 915c02e8e5dd..ca7ed5158cff 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -382,7 +382,7 @@ static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end, 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 start_pfn, unsigned long nr_pages, 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; -- 2.19.1