From patchwork Fri Dec 7 13:28:34 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tim Gardner X-Patchwork-Id: 204482 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id EB0B52C00FE for ; Sat, 8 Dec 2012 00:29:18 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030354Ab2LGN25 (ORCPT ); Fri, 7 Dec 2012 08:28:57 -0500 Received: from mail.tpi.com ([70.99.223.143]:1813 "EHLO mail.tpi.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030293Ab2LGN2z (ORCPT ); Fri, 7 Dec 2012 08:28:55 -0500 Received: from salmon.rtg.net (mail.tpi.com [70.99.223.143]) by mail.tpi.com (Postfix) with ESMTP id 6C95D32DB8F; Fri, 7 Dec 2012 05:28:46 -0800 (PST) Received: by salmon.rtg.net (Postfix, from userid 1000) id EEB46217B2; Fri, 7 Dec 2012 06:28:45 -0700 (MST) From: Tim Gardner To: linux-kernel@vger.kernel.org Cc: Tim Gardner , Johannes Berg , Wey-Yi Guy , Intel Linux Wireless , "John W. Linville" , Emmanuel Grumbach , Don Fry , linux-wireless@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH V2 wireless-next] iwlwifi: iwlagn_request_scan: Fix check for priv->scan_request Date: Fri, 7 Dec 2012 06:28:34 -0700 Message-Id: <1354886914-7822-1-git-send-email-tim.gardner@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1354830114.18211.4.camel@jlt4.sipsolutions.net> References: <1354830114.18211.4.camel@jlt4.sipsolutions.net> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The WARN_ON_ONCE() check for scan_request will not correctly detect a NULL pointer for scan_type == IWL_SCAN_NORMAL. Make it explicit that the check only applies to normal scans. Convert WARN_ON_ONCE to WARN_ON since priv->scan_request really _can't_ be NULL for normal scans. If it is then we should emit frequent warnings. This smatch warning led to scrutiny of iwlagn_request_scan(): drivers/net/wireless/iwlwifi/dvm/scan.c:894 iwlagn_request_scan() error: we previously assumed 'priv->scan_request' could be null (see line 792) Cc: Johannes Berg Cc: Wey-Yi Guy Cc: Intel Linux Wireless Cc: "John W. Linville" Cc: Emmanuel Grumbach Cc: Don Fry Cc: linux-wireless@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Tim Gardner --- This patch does apply to 3.6.y, but it doesn't fix an existing bug so I don't think it qualifies. This patch simply makes the driver more robust for future development. V2 - corrected indentation more like the rest of the source in this file. drivers/net/wireless/iwlwifi/dvm/scan.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/dvm/scan.c b/drivers/net/wireless/iwlwifi/dvm/scan.c index bb9f625..fe91c5a 100644 --- a/drivers/net/wireless/iwlwifi/dvm/scan.c +++ b/drivers/net/wireless/iwlwifi/dvm/scan.c @@ -673,8 +673,9 @@ static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif) const u8 *ssid = NULL; u8 ssid_len = 0; - if (WARN_ON_ONCE(priv->scan_request && - priv->scan_request->n_channels > MAX_SCAN_CHANNEL)) + if (WARN_ON(priv->scan_type == IWL_SCAN_NORMAL && + (!priv->scan_request || + priv->scan_request->n_channels > MAX_SCAN_CHANNEL))) return -EINVAL; lockdep_assert_held(&priv->mutex);