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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 B0097C2BB85 for ; Thu, 16 Apr 2020 14:35:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8FD9D21D7E for ; Thu, 16 Apr 2020 14:35:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587047738; bh=jDt6vkUMyGZfura59hrrftwobQmgudUKhDGGO98R2Z4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Sv9AumUsWZhMaorZWWagc6/m/WSR6O0X630B8nFUag/MSV5/PNzkBjNurixxFaPdj AofLC5dJf8DCtadZcPENiRXNgS4cGV5XL3E8f4JGJ5HfJot/n8KLx6A+wvO21C/XPf AAdTnB65JBfXB/5l1MCXaWFZxB4b3fkUQMaq6PBI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438787AbgDPORW (ORCPT ); Thu, 16 Apr 2020 10:17:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:38956 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2440349AbgDPNwg (ORCPT ); Thu, 16 Apr 2020 09:52:36 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 D6EAE2078B; Thu, 16 Apr 2020 13:52:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587045156; bh=jDt6vkUMyGZfura59hrrftwobQmgudUKhDGGO98R2Z4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZVFJceqITjpv/OnJnO8ZS6j1X5kfsslNweMVPBsIdfN5mOCU8mICaUmii8brz9sA5 74yzfSb5oXl8f+SmoMl3IurzMFYpDvBDx7N68+/XWL8EB13baKVa0jkMcdKotPyc/v zfYvMarESzdwvF2LsxYo7jz3RlI03VAI9iI3fX64= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bart Van Assche , Chaitanya Kulkarni , Johannes Thumshirn , Hannes Reinecke , Ming Lei , Christoph Hellwig , Jens Axboe , Sasha Levin Subject: [PATCH 5.6 020/254] null_blk: Suppress an UBSAN complaint triggered when setting memory_backed Date: Thu, 16 Apr 2020 15:21:49 +0200 Message-Id: <20200416131328.342674812@linuxfoundation.org> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200416131325.804095985@linuxfoundation.org> References: <20200416131325.804095985@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Bart Van Assche [ Upstream commit b9853b4d6fb403ccb1d4d82e2d39fc17fc07519c ] Although it is not clear to me why UBSAN complains when 'memory_backed' is set, this patch suppresses the UBSAN complaint that is triggered when setting that configfs attribute. UBSAN: Undefined behaviour in drivers/block/null_blk_main.c:327:1 load of value 16 is not a valid value for type '_Bool' CPU: 2 PID: 8396 Comm: check Not tainted 5.6.0-rc1-dbg+ #14 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: dump_stack+0xa5/0xe6 ubsan_epilogue+0x9/0x26 __ubsan_handle_load_invalid_value+0x6d/0x76 nullb_device_memory_backed_store.cold+0x2c/0x38 [null_blk] configfs_write_file+0x1c4/0x250 [configfs] __vfs_write+0x4c/0x90 vfs_write+0x145/0x2c0 ksys_write+0xd7/0x180 __x64_sys_write+0x47/0x50 do_syscall_64+0x6f/0x2f0 entry_SYSCALL_64_after_hwframe+0x49/0xbe Signed-off-by: Bart Van Assche Reviewed-by: Chaitanya Kulkarni Cc: Johannes Thumshirn Cc: Hannes Reinecke Cc: Ming Lei Cc: Christoph Hellwig Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/null_blk_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c index d5b4a92033d48..2b8b4cb447cfb 100644 --- a/drivers/block/null_blk_main.c +++ b/drivers/block/null_blk_main.c @@ -276,7 +276,7 @@ nullb_device_##NAME##_store(struct config_item *item, const char *page, \ { \ int (*apply_fn)(struct nullb_device *dev, TYPE new_value) = APPLY;\ struct nullb_device *dev = to_nullb_device(item); \ - TYPE uninitialized_var(new_value); \ + TYPE new_value = 0; \ int ret; \ \ ret = nullb_device_##TYPE##_attr_store(&new_value, page, count);\ -- 2.20.1