Return-path: Received: from rv-out-0506.google.com ([209.85.198.231]:14354 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753324AbYIOToa (ORCPT ); Mon, 15 Sep 2008 15:44:30 -0400 Received: by rv-out-0506.google.com with SMTP id k40so2298922rvb.1 for ; Mon, 15 Sep 2008 12:44:30 -0700 (PDT) Message-ID: <45e8e6c40809151244n6c337ef4x65ecce0bcfea3e05@mail.gmail.com> (sfid-20080915_214434_871911_603FF374) Date: Mon, 15 Sep 2008 12:44:29 -0700 From: "Andrey Yurovsky" To: "Dan Williams" Subject: Re: [RFC PATCH] libertas_tf: clear current command on remove Cc: "Luis Carlos Cobo" , linux-wireless@vger.kernel.org In-Reply-To: <1221463292.27102.93.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 References: <1220906082.1618.22.camel@localhost.localdomain> <45e8e6c40809111535k153af71fga6e80e43aef6cbef@mail.gmail.com> <1221463292.27102.93.camel@localhost.localdomain> Sender: linux-wireless-owner@vger.kernel.org List-ID: Sorry, I get the same oops after that change as well. On Mon, Sep 15, 2008 at 12:21 AM, Dan Williams wrote: > On Thu, 2008-09-11 at 15:35 -0700, Andrey Yurovsky wrote: >> Hi Dan. With this patch, I get a NULL pointer dereference if I pull >> the card while scanning: > > So the USB disconnect calls lbs_remove_card(), which first calls > lbtf_free_adapter() (clearing the entire command array), and then it > calls ieee80211_unregister_hw(), which calls lbs_op_stop(), which clears > the current command node, and then ieee80211_unregister_hw() calls > flush_workqueue() on the work queue that the scan could currently be > pending in. > > The scan command, currently blocking in __lbtf_cmd() in > wait_event_interruptible(), now gets woken up because of my patch to > lbs_op_stop(). Its flow continues through __lbtf_cmd() until > __lbtf_cleanup_and_insert_cmd(), where it tries a > memset(cmdnode->cmdbuf, 0, ...). Unfortunately, cmdnode->cmdbuf is now > NULL, having been cleared in lbtf_free_cmd_buffer() already by > lbtf_free_adapter() quite early in the device removal chain. Explosion. > > About all I can think of right now is something like: > > diff --git a/drivers/net/wireless/libertas_tf/cmd.c b/drivers/net/wireless/libertas_tf/cmd.c > index fdbcf8b..481d189 100644 > --- a/drivers/net/wireless/libertas_tf/cmd.c > +++ b/drivers/net/wireless/libertas_tf/cmd.c > @@ -550,11 +550,16 @@ int __lbtf_cmd(struct lbtf_private *priv, uint16_t command, > might_sleep(); > ret = wait_event_interruptible(cmdnode->cmdwait_q, > cmdnode->cmdwaitqwoken); > - if (ret) { > + if (ret) { > printk(KERN_DEBUG > "libertastf: command 0x%04x interrupted by signal", > command); > return ret; > + } else if (priv->surpriseremoved) { > + printk(KERN_DEBUG > + "libertastf: command 0x%04x interrupted by device " > + "disconnect", command); > + return -ENODEV; > } > > spin_lock_irqsave(&priv->driver_lock, flags); > > Does that fix it for you? If so, I'll roll this one up with the > previous patch and resubmit. > > Dan > >> 6>[ 131.596162] libertastf: URB in failure status: -71 >> <6>[ 131.712016] usb 4-5: USB disconnect, address 5 >> <7>[ 131.933390] libertastf: command 0x001d failed: -2 >> <1>[ 131.933429] BUG: unable to handle kernel NULL pointer >> dereference at 00000000 >> <1>[ 131.933437] IP: [] >> :libertas_tf:__lbtf_cleanup_and_insert_cmd+0x2e/0x60 >> <4>[ 131.933452] *pde = 00000000 >> <0>[ 131.933511] Oops: 0002 [#1] SMP >> <4>[ 131.933519] Modules linked in: arc4 ecb crypto_blkcipher >> libertas_tf_usb libertas_tf mac80211 cfg80211 binfmt_misc radeon drm >> rfcomm l2cap bluetooth nfsd auth_rpcgss exportfs speedstep_lib >> cpufreq_userspace cpufreq_stats cpufreq_powersave cpufreq_ondemand >> freq_table cpufreq_conservative video output rfkill input_polldev sbs >> sbshc battery nfs lockd nfs_acl sunrpc iptable_filter ip_tables >> x_tables ac ppdev psmouse serio_raw yenta_socket rsrc_nonstatic >> container parport_pc parport pcspkr iTCO_wdt iTCO_vendor_support >> button intel_agp agpgart shpchp pci_hotplug ipv6 evdev ext3 jbd >> mbcache usbhid hid sg sr_mod sd_mod cdrom ata_piix pata_acpi b44 >> floppy ata_generic libata scsi_mod dock ssb pcmcia pcmcia_core mii >> ehci_hcd uhci_hcd usbcore thermal processor fan thermal_sys fuse >> <4>[ 131.934926] >> <4>[ 131.934931] Pid: 6090, comm: usb Not tainted (2.6.27-rc6-wl #1) >> <4>[ 131.934963] EIP: 0060:[] EFLAGS: 00010046 CPU: 0 >> <4>[ 131.934999] EIP is at __lbtf_cleanup_and_insert_cmd+0x2e/0x60 >> [libertas_tf] >> <4>[ 131.935032] EAX: 00000000 EBX: f4f372f0 ECX: 00000200 EDX: f4f372f0 >> <4>[ 131.935037] ESI: f751ee60 EDI: 00000000 EBP: f751ee60 ESP: f40efecc >> <4>[ 131.935069] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 >> <0>[ 131.935101] Process usb (pid: 6090, ti=f40ee000 task=f7530fc0 >> task.ti=f40ee000) >> <0>[ 131.935106] Stack: f751f7d4 fffffffe 00000282 f8d72133 f8d72e88 >> 0000001d fffffffe 0000001d >> <0>[ 131.935177] f4f372f0 00000000 f7530fc0 c013c580 f40efefc >> f40efefc f751e1a0 f751fb48 >> <0>[ 131.935275] f751f938 f4110480 f8d7225a 00000030 f8d725d0 >> f40eff24 00300001 c0102c05 >> <0>[ 131.935478] Call Trace: >> <0>[ 131.935509] [] __lbtf_cmd+0xd3/0x130 [libertas_tf] >> <0>[ 131.935551] [] autoremove_wake_function+0x0/0x40 >> <0>[ 131.935589] [] lbtf_set_channel+0x3a/0x40 [libertas_tf] >> <0>[ 131.935600] [] lbtf_cmd_copyback+0x0/0x50 [libertas_tf] >> <0>[ 131.935637] [] __switch_to+0xa5/x160 >> <0>[ 131.935644] [] finish_task_switch+0x1f/0xb0 >> <0>[ 131.935652] [] schedule+0x25b/0x6a0 >> <0>[ 131.935660] [] lbtf_op_config+0x26/0x0 [libertas_tf] >> <0>[ 11.935750] [ ieee80211_hw_config+056/0x70 [mac80211] >> <0[ 131.935803] [] ieee80211_sta_scn_work+0x179/0x1e0 [ma80211] >> <0>[ 131.93585] [] queue_elayed_work_on+0x84/0x0 >> <0>[ 131.935887] [c013909a>] run_workquee+0xca/0x170 >> <0>[ 131935949] []_spin_lock_irqsave+0x3/0x50 >> <0>[ 131.936036] [] ieee8021_sta_scan_work+0x0/0xe0 [mac80211] >> <0>[ 13.936085] []worker_thread+0x0/0xe0 >> 0>[ 131.936119] [] worker_thread+x80/0xe0 >> <0>[ 131.93679] [] autoemove_wake_function+0x/0x40 >> <0>[ 131.936239 [] workerthread+0x0/0xe0 >> <0>[ 31.936299] [> <0013c20>] kthread+0x0/0x70 >> <0[ 131.936392] [] kernel_thread_heper+0x7/0x10 >> <0>[ 131936453] ====================== >> <0>[ 131.93509] Code: 85 d2 89 1c24 89 d3 89 74 24 04 8 c6 89 7c 24 >> 08 74 33 c 42 0c 00 00 00 00 31 0 b9 00 02 00 00 c7 4210 00 00 00 00 >> 8b 7a 1 ab 8b 96 68 09 0 00 8d 86 64 09 00 00 9 9e 68 09 00 00 89 >> <>[ 131.937384] EIP: [f8d71d7e>] >> __lbtf_clenup_and_insert_cmd+0x2/0x60 [libertas_tf] SSESP >> 0068:f40efecc >> <4>[ 131.937384] ---[ endtrace 32fe8679f56e2101]--- >> >> >> On Mon, Sep 8, 2008 at 1:34 PM, Dan Williams wrote: >> > Ensure that the current command is torn down when cleaning up. >> > >> > Signed-off-by: Dan Williams >> > --- >> > >> > Completely untested but based on the libertas patch for the same >> > problem. Luis, can you give it a shot and make sure there aren't any >> > regressions when pulling the card or rmmod-ing the driver? >> > >> > diff --git a/drivers/net/wireless/libertas_tf/main.c b/drivers/net/wireless/libertas_tf/main.c >> > index c948021..5f7bf04 100644 >> > --- a/drivers/net/wireless/libertas_tf/main.c >> > +++ b/drivers/net/wireless/libertas_tf/main.c >> > @@ -296,8 +296,8 @@ static void lbtf_op_stop(struct ieee80211_hw *hw) >> > struct lbtf_private *priv = hw->priv; >> > unsigned long flags; >> > struct sk_buff *skb; >> > - >> > struct cmd_ctrl_node *cmdnode; >> > + >> > /* Flush pending command nodes */ >> > spin_lock_irqsave(&priv->driver_lock, flags); >> > list_for_each_entry(cmdnode, &priv->cmdpendingq, list) { >> > @@ -306,7 +306,14 @@ static void lbtf_op_stop(struct ieee80211_hw *hw) >> > wake_up_interruptible(&cmdnode->cmdwait_q); >> > } >> > >> > + /* Flush the command the card is currently processing */ >> > + if (priv->cur_cmd) { >> > + priv->cur_cmd->result = -ENOENT; >> > + priv->cur_cmd->cmdwaitqwoken = 1; >> > + wake_up_interruptible(&priv->cur_cmd->cmdwait_q); >> > + } >> > spin_unlock_irqrestore(&priv->driver_lock, flags); >> > + >> > cancel_work_sync(&priv->cmd_work); >> > cancel_work_sync(&priv->tx_work); >> > while ((skb = skb_dequeue(&priv->bc_ps_buf))) >> > >> > >> > -- >> > To unsubscribe from this list: send the line "unsubscribe linux-wireless" in >> > the body of a message to majordomo@vger.kernel.org >> > More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > >