From patchwork Tue May 23 08:58:07 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arend Van Spriel X-Patchwork-Id: 9742171 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id D154060380 for ; Tue, 23 May 2017 08:58:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C558D2876A for ; Tue, 23 May 2017 08:58:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B9FBD287B6; Tue, 23 May 2017 08:58:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DC26C2876A for ; Tue, 23 May 2017 08:58:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967110AbdEWI6Z (ORCPT ); Tue, 23 May 2017 04:58:25 -0400 Received: from lpdvrndsmtp01.broadcom.com ([192.19.229.170]:45763 "EHLO rnd-relay.smtp.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967082AbdEWI6U (ORCPT ); Tue, 23 May 2017 04:58:20 -0400 Received: from mail-irv-17.broadcom.com (mail-irv-17.lvn.broadcom.net [10.75.224.233]) by rnd-relay.smtp.broadcom.com (Postfix) with ESMTP id 7E7D430C027; Tue, 23 May 2017 01:58:18 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.10.3 rnd-relay.smtp.broadcom.com 7E7D430C027 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=broadcom.com; s=dkimrelay; t=1495529898; bh=SeIKPRVEp0L3o12b8lNK85KQV0z+SjW2y+ln/MqkOAg=; h=From:To:Cc:Subject:Date:From; b=oyYN4bU+/OuRpuEafd6trXDPv733M8TxV7jeo/ICng1r8ck8ipE5L/IGZORJZ/7ic VOeocKRw+FXVIyVRtUBzibIMzd/Wq4c13ea5Sg5E1UOVkFXXkqB7ZTjqorfVIj3wGi dDGmNZOiWWAx0Ia9qY5iXAbb7HgINjdM6/oAHuTg= Received: from jenkins-cam-14.cam.broadcom.com (jenkins-cam-14.cam.broadcom.com [10.177.128.77]) by mail-irv-17.broadcom.com (Postfix) with ESMTP id EAAC181EE7; Tue, 23 May 2017 01:58:17 -0700 (PDT) Received: by jenkins-cam-14.cam.broadcom.com (Postfix, from userid 25152) id CBC54B82856; Tue, 23 May 2017 09:58:09 +0100 (BST) From: Arend van Spriel To: Johannes Berg Cc: linux-wireless@vger.kernel.org, Arend van Spriel Subject: [PATCH] cfg80211: make cfg80211_sched_scan_results() work from atomic context Date: Tue, 23 May 2017 09:58:07 +0100 Message-Id: <1495529887-14542-1-git-send-email-arend.vanspriel@broadcom.com> X-Mailer: git-send-email 1.9.1 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Drivers should be able to call cfg80211_sched_scan_results() from atomic context. However, with the introduction of multiple scheduled scan feature this requirement was not taken into account resulting in regression shown below. [ 119.021594] BUG: scheduling while atomic: irq/47-iwlwifi/517/0x00000200 [ 119.021604] Modules linked in: xt_tcpudp ip6t_rpfilter ipt_REJECT nf_reject_ipv4 ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_raw ip6table_security ip6table_mangle iptable_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_security iptable_mangle ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter ip_tables x_tables rfcomm bnep binfmt_misc arc4 iTCO_wdt iTCO_vendor_support uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core videodev intel_rapl cdc_mbim iwlmvm x86_pkg_temp_thermal intel_powerclamp mac80211 media cdc_wdm btusb coretemp cdc_ncm kvm_intel usbnet mii cdc_acm iwlwifi kvm btintel joydev pcspkr serio_raw cfg80211 snd_hda_codec_hdmi [ 119.021701] bluetooth lpc_ich snd_hda_codec_realtek snd_hda_codec_generic shpchp sg ecdh_generic snd_hda_intel thinkpad_acpi snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer nvram snd soundcore evdev tpm_tis tpm_tis_core tpm algif_skcipher af_alg crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel rtsx_pci_sdmmc mmc_core aesni_intel aes_x86_64 crypto_simd cryptd glue_helper psmouse i2c_i801 sd_mod ehci_pci ehci_hcd e1000e rtsx_pci mfd_core ptp xhci_pci pps_core xhci_hcd [ 119.021759] CPU: 1 PID: 517 Comm: irq/47-iwlwifi Not tainted 4.12.0-rc2-t440s-20170522+ #1 [ 119.021763] Hardware name: LENOVO 20AQS03H00/20AQS03H00, BIOS GJET91WW (2.41 ) 09/21/2016 [ 119.021766] Call Trace: [ 119.021778] ? dump_stack+0x5c/0x84 [ 119.021784] ? __schedule_bug+0x4c/0x70 [ 119.021792] ? __schedule+0x496/0x5c0 [ 119.021798] ? schedule+0x2d/0x80 [ 119.021804] ? schedule_preempt_disabled+0x5/0x10 [ 119.021810] ? __mutex_lock.isra.0+0x18e/0x4c0 [ 119.021817] ? __wake_up+0x2f/0x50 [ 119.021833] ? cfg80211_sched_scan_results+0x19/0x60 [cfg80211] [ 119.021844] ? cfg80211_sched_scan_results+0x19/0x60 [cfg80211] [ 119.021859] ? iwl_mvm_rx_lmac_scan_iter_complete_notif+0x17/0x30 [iwlmvm] [ 119.021869] ? iwl_pcie_rx_handle+0x2a9/0x7e0 [iwlwifi] [ 119.021878] ? iwl_pcie_irq_handler+0x17c/0x730 [iwlwifi] [ 119.021884] ? irq_forced_thread_fn+0x60/0x60 [ 119.021887] ? irq_thread_fn+0x16/0x40 [ 119.021892] ? irq_thread+0x109/0x180 [ 119.021896] ? wake_threads_waitq+0x30/0x30 [ 119.021901] ? kthread+0xf2/0x130 [ 119.021905] ? irq_thread_dtor+0x90/0x90 [ 119.021910] ? kthread_create_on_node+0x40/0x40 [ 119.021915] ? ret_from_fork+0x26/0x40 Fixes: b34939b98369 ("cfg80211: add request id to cfg80211_sched_scan_*() api") Reported-by: Sander Eikelenboom Signed-off-by: Arend van Spriel --- net/wireless/scan.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 14d5f0c..9f0901f 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -322,9 +322,9 @@ static void cfg80211_del_sched_scan_req(struct cfg80211_registered_device *rdev, { struct cfg80211_sched_scan_request *pos; - ASSERT_RTNL(); + WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held()); - list_for_each_entry(pos, &rdev->sched_scan_req_list, list) { + list_for_each_entry_rcu(pos, &rdev->sched_scan_req_list, list) { if (pos->reqid == reqid) return pos; } @@ -398,13 +398,13 @@ void cfg80211_sched_scan_results(struct wiphy *wiphy, u64 reqid) trace_cfg80211_sched_scan_results(wiphy, reqid); /* ignore if we're not scanning */ - rtnl_lock(); + rcu_read_lock(); request = cfg80211_find_sched_scan_req(rdev, reqid); if (request) { request->report_results = true; queue_work(cfg80211_wq, &rdev->sched_scan_res_wk); } - rtnl_unlock(); + rcu_read_unlock(); } EXPORT_SYMBOL(cfg80211_sched_scan_results);