Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79E41C433EF for ; Thu, 18 Nov 2021 14:21:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 59BB261406 for ; Thu, 18 Nov 2021 14:21:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232711AbhKROYb (ORCPT ); Thu, 18 Nov 2021 09:24:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:45364 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232554AbhKROYa (ORCPT ); Thu, 18 Nov 2021 09:24:30 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9D2B8610FB; Thu, 18 Nov 2021 14:21:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1637245290; bh=fWB+uwrmZcbW6kM5Y415Yic83y10eXZ6Qv7v9+poSe0=; h=From:To:Cc:Subject:Date:From; b=j7+frcX8se6gNR5EoEgrgNfpS9egBAE9np97ul75Q9HNWcqr3Yeadz1B4qgpeMgo9 Eqt6DOgHVFqdA77CGHEOW3vRtlxGgst94oWTv03nq85nfuK0+sbx4OI8zLreXIhBWm eo2ynjD94dxiC88outwfZ/TEBuaNOshAj02mGe9ZgRKWxJJ4XUaSCLqt/x0YkYSz0g nosDxzbHSKtzELI6GMmvJx9GIKBayxejrh+o6vcmPckAR3SWvJQYFq14fKy+N6tWNZ vxk381jVpNiEtw3qzh1LYvCZ04tlUj4F7+/ra0OZAkBTbL88He0OpG+e4KCpbzEeIr 8IpZ73s+g1afw== From: Arnd Bergmann To: Luca Coelho , Kalle Valo Cc: Arnd Bergmann , kernel test robot , Nick Desaulniers , "David S. Miller" , Jakub Kicinski , Nathan Chancellor , Johannes Berg , Yaara Baruch , Matti Gottlieb , Emmanuel Grumbach , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH] [v3] iwlwifi: pcie: fix constant-conversion warning Date: Thu, 18 Nov 2021 15:21:02 +0100 Message-Id: <20211118142124.526901-1-arnd@kernel.org> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Arnd Bergmann gcc-11 points out a potential issue with integer overflow when the iwl_dev_info_table[] array is empty: drivers/net/wireless/intel/iwlwifi/pcie/drv.c:1344:42: error: implicit conversion from 'unsigned long' to 'int' changes value from 18446744073709551615 to -1 [-Werror,-Wconstant-conversion] for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) { ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~ This is still harmless, as the loop correctly terminates, but adding an extra range check makes that obvious to both readers and to the compiler. Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()") Reported-by: kernel test robot Cc: Nick Desaulniers Signed-off-by: Arnd Bergmann --- Changes in v3: - make it actually work with gcc-11 - fix commit message s/clang/gcc-11/ Changes in v2: - replace int cast with a range check --- drivers/net/wireless/intel/iwlwifi/pcie/drv.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c index c574f041f096..395e328c6a07 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c @@ -1339,9 +1339,13 @@ iwl_pci_find_dev_info(u16 device, u16 subsystem_device, u16 mac_type, u8 mac_step, u16 rf_type, u8 cdb, u8 rf_id, u8 no_160, u8 cores) { + int num_devices = ARRAY_SIZE(iwl_dev_info_table); int i; - for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) { + if (!num_devices) + return NULL; + + for (i = num_devices - 1; i >= 0; i--) { const struct iwl_dev_info *dev_info = &iwl_dev_info_table[i]; if (dev_info->device != (u16)IWL_CFG_ANY && -- 2.29.2