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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,T_DKIMWL_WL_HIGH, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id 376B7C5CFF1 for ; Tue, 12 Jun 2018 16:48:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E1779208BA for ; Tue, 12 Jun 2018 16:48:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="JgGA+IXO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E1779208BA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933779AbeFLQsN (ORCPT ); Tue, 12 Jun 2018 12:48:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:34058 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934947AbeFLQsF (ORCPT ); Tue, 12 Jun 2018 12:48:05 -0400 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9B565208B7; Tue, 12 Jun 2018 16:48:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1528822085; bh=w72pDsf1zlgltY+4KdYrsYI7usLj0Exu/QM9ZIFClSE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JgGA+IXOYHuDJoJFAz5mWJ6qUes+68okNbfKcyCtGE43EPvk7wAyNpSRDNzNAO8Kt 53cSxq1hnRwx4zz9yPPLQ8pMlEpceWVWZ4ntxc3yNL48GKVytvgif/dZJRrXXsXQW6 hzvqxLDlK2FpTUsTPM2xDyZheoke3X4l9JP8B81A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Arnd Bergmann , Mike Snitzer , Nathan Chancellor Subject: [PATCH 4.9 29/31] dm bufio: avoid false-positive Wmaybe-uninitialized warning Date: Tue, 12 Jun 2018 18:46:32 +0200 Message-Id: <20180612164621.948353741@linuxfoundation.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180612164620.797338191@linuxfoundation.org> References: <20180612164620.797338191@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arnd Bergmann commit 590347e4000356f55eb10b03ced2686bd74dab40 upstream. gcc-6.3 and earlier show a new warning after a seemingly unrelated change to the arm64 PAGE_KERNEL definition: In file included from drivers/md/dm-bufio.c:14:0: drivers/md/dm-bufio.c: In function 'alloc_buffer': include/linux/sched/mm.h:182:56: warning: 'noio_flag' may be used uninitialized in this function [-Wmaybe-uninitialized] current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags; ^ The same warning happened earlier on linux-3.18 for MIPS and I did a workaround for that, but now it's come back. gcc-7 and newer are apparently smart enough to figure this out, and other architectures don't show it, so the best I could come up with is to rework the caller slightly in a way that makes it obvious enough to all arm64 compilers what is happening here. Fixes: 41acec624087 ("arm64: kpti: Make use of nG dependent on arm64_kernel_unmapped_at_el0()") Link: https://patchwork.kernel.org/patch/9692829/ Cc: stable@vger.kernel.org Signed-off-by: Arnd Bergmann [snitzer: moved declarations inside conditional, altered vmalloc return] Signed-off-by: Mike Snitzer [nc: Backport to 4.9, adjust context for lack of 19809c2da28a] Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-bufio.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -373,9 +373,6 @@ static void __cache_size_refresh(void) static void *alloc_buffer_data(struct dm_bufio_client *c, gfp_t gfp_mask, enum data_mode *data_mode) { - unsigned noio_flag; - void *ptr; - if (c->block_size <= DM_BUFIO_BLOCK_SIZE_SLAB_LIMIT) { *data_mode = DATA_MODE_SLAB; return kmem_cache_alloc(DM_BUFIO_CACHE(c), gfp_mask); @@ -399,16 +396,16 @@ static void *alloc_buffer_data(struct dm * all allocations done by this process (including pagetables) are done * as if GFP_NOIO was specified. */ + if (gfp_mask & __GFP_NORETRY) { + unsigned noio_flag = memalloc_noio_save(); + void *ptr = __vmalloc(c->block_size, gfp_mask | __GFP_HIGHMEM, + PAGE_KERNEL); - if (gfp_mask & __GFP_NORETRY) - noio_flag = memalloc_noio_save(); - - ptr = __vmalloc(c->block_size, gfp_mask | __GFP_HIGHMEM, PAGE_KERNEL); - - if (gfp_mask & __GFP_NORETRY) memalloc_noio_restore(noio_flag); + return ptr; + } - return ptr; + return __vmalloc(c->block_size, gfp_mask | __GFP_HIGHMEM, PAGE_KERNEL); } /*