#472: Device Driver Crashes, Kernel Panics and Locking Problems
-----------------------------------+----------------------------------------
Reporter: [EMAIL PROTECTED] | Owner: mrenzmann
Type: defect | Status: assigned
Priority: major | Milestone: version 0.9.0 - move to new
codebase
Component: madwifi: driver | Version: trunk
Resolution: | Keywords:
Patch_attached: 1 |
-----------------------------------+----------------------------------------
Comment (by [EMAIL PROTECTED]):
Sending wireless traffic through the interface is solid with Daniel Wu's
20050331 patch. My kernel is built with spinlock (and all else) debugging;
I am seeing this failure when removing the modules:
{{{
# ifdown wlan0 && rmmod ath_pci ath_rate_sample ath_hal
BUG: spinlock recursion on CPU#0, wlanconfig/6522
lock: f7b2eb94, .magic: dead4ead, .owner: wlanconfig/6522, .owner_cpu: 0
[<c01041fd>] show_trace+0xd/0x10
[<c0104217>] dump_stack+0x17/0x20
[<c01d29ee>] spin_bug+0x9e/0xc0
[<c01d2d64>] _raw_spin_lock+0x154/0x160
[<c02cd568>] _spin_lock+0x8/0x10
[<f88f104b>] acl_free_all_locked+0xb/0x40 [wlan_acl]
[<f88f10a3>] acl_detach+0x23/0x60 [wlan_acl]
[<f8959e76>] ieee80211_proto_vdetach+0x26/0x30 [wlan]
[<f8947505>] ieee80211_vap_detach+0x95/0x130 [wlan]
[<f8908f7a>] ath_vap_delete+0x10a/0x320 [ath_pci]
[<f896245c>] ieee80211_ioctl+0x9c/0x550 [wlan]
[<c0264368>] dev_ifsioc+0xe8/0x360
[<c0264867>] dev_ioctl+0x227/0x3e0
[<c025923a>] sock_ioctl+0x3a/0x270
[<c0165330>] do_ioctl+0x20/0x70
[<c01653d7>] vfs_ioctl+0x57/0x2b0
[<c0165669>] sys_ioctl+0x39/0x60
[<c0102e01>] syscall_call+0x7/0xb
}}}
From the code, it is clear that
net80211/ieee80211_acl.c::acl_free_all_locked() is taking the ACL spinlock
a second time; it is taken the first time in the call-site in
net80211/ieee80211_acl.c::acl_detach().
I updated Daniel Wu's great patch with a fix for this - further testing
has shown no load/unload and in-use problems on my 2.6.16 preempt+debug
kernel.
Perhaps this can be committed for wider testing soon, since the current
SVN head is really broken?
Signed-off-by: Daniel J Blueman <[EMAIL PROTECTED]>
--
Ticket URL: <http://madwifi.org/ticket/472>
MadWifi <http://madwifi.org/>
Multiband Atheros Driver for Wireless Fidelity
