Most recent kernel where this bug did not occur: n/a
Distribution: OpenZaurus (unstable)
Hardware Environment: arm (Zaurus C3100)
Software Environment: OpenZaurus distro
Problem Description: 
if a bluetooth card is inserted which is driven by the serial_cs driver, a
hciattach helper process has to be started by cardmgr in order to use the card
via rfcomm. if the card gets removed from the system the hciattach process
should vanish, because after re-insertion a new hciattach process must be
started anyway (it's not possible to reuse the old process).
unfortunately the process doesn't get killed properly via the cardmgr scripts
and if you try to kill the process after removal of the card a kernel oops
appears and the process is stuck for good (see the kernel trace below).
funny enough it is possible to kill the hciattach properly if you re-insert the
card and start a new hciattach manually afterwards.
but it seems to me that there is no proper way within the pcmcia-cs framework to
get around that race situation, i.e. killing the hciattach process _before_ the
serial_cs module gets unloaded ...

Steps to reproduce:
- you need a bluetooth card which is driven by serial_cs (billionton cf card in
my case)
- after card insertion serial_cs module gets loaded by cardmgr and a hciattach
will be spawn 
- remove the card (either by ejecting via cardctl or by removing the real card
from the cf socket)
- hciattach won't get killed (though it should be by cardmgr)
- kill the hciattach process (while the card is _NOT_ inserted)

kernel trace:

Jan 12 13:43:39 borzoi user.err kernel: serial8250: too much work for irq137
Jan 12 13:43:40 borzoi user.notice kernel: pccard: card ejected from slot 1
Jan 12 13:43:40 borzoi daemon.info cardmgr[2576]: shutting down socket 1
Jan 12 13:43:40 borzoi daemon.info cardmgr[2576]: executing: './serial stop ttyS3'
Jan 12 13:43:41 borzoi daemon.info cardmgr[2576]: + /dev/ttyS3:
Jan 12 13:43:41 borzoi daemon.info cardmgr[2576]: + /dev/ttyS3:
Jan 12 13:43:41 borzoi daemon.info cardmgr[2576]: + /dev/modem:
Jan 12 13:43:41 borzoi daemon.info cardmgr[2576]: + killall hciattach
Jan 12 13:43:43 borzoi user.alert kernel: Unable to handle kernel NULL pointer
dereference at virtual address 00000008
Jan 12 13:43:43 borzoi user.alert kernel: pgd = c0004000
Jan 12 13:43:43 borzoi user.alert kernel: [00000008] *pgd=00000000
Jan 12 13:43:43 borzoi user.warn kernel: Internal error: Oops: 817 [#1]
Jan 12 13:43:43 borzoi user.warn kernel: Modules linked in: serial_cs 8250
hci_uart ohci_hcd usbcore snd_soc_spitz snd_soc_pxa2xx_i2s snd_soc_wm8750
snd_soc_pxa2xx snd_soc_core snd_pcm_oss snd_pcm snd_timer snd_page_alloc
snd_mixer_oss snd soundcore rfcomm pxaficp_ir ircomm_tty ircomm irda ipv6 hidp
l2cap bluetooth
Jan 12 13:43:43 borzoi user.warn kernel: CPU: 0
Jan 12 13:43:43 borzoi user.warn kernel: PC is at uart_flush_buffer+0x3c/0x74
Jan 12 13:43:43 borzoi user.warn kernel: LR is at hci_uart_flush+0x88/0xb4
[hci_uart]
Jan 12 13:43:43 borzoi user.warn kernel: pc : [<c014b288>]    lr : [<bf124324>]
   Not tainted
Jan 12 13:43:43 borzoi user.warn kernel: sp : c1ac7cc0  ip : c3f42b40  fp : c1ac7cd0
Jan 12 13:43:43 borzoi user.warn kernel: r10: 00000938  r9 : c1ad8938  r8 : 00000000
Jan 12 13:43:43 borzoi user.warn kernel: r7 : 00000000  r6 : 00000000  r5 :
c1ad8000  r4 : c1ad8000
Jan 12 13:43:43 borzoi user.warn kernel: r3 : 00000000  r2 : c1ac6000  r1 :
00000000  r0 : a0000013
Jan 12 13:43:43 borzoi user.warn kernel: Flags: NzCv  IRQs off  FIQs on  Mode
SVC_32  Segment user
Jan 12 13:43:43 borzoi user.warn kernel: Control: 397F  Table: A1830000  DAC:
00000015
Jan 12 13:43:43 borzoi user.warn kernel: Process hciattach (pid: 3203, stack
limit = 0xc1ac61a4)
Jan 12 13:43:43 borzoi user.warn kernel: Stack: (0xc1ac7cc0 to 0xc1ac8000)
Jan 12 13:43:43 borzoi user.warn kernel: 7cc0: c1bc07a0 c1ac7ce8 c1ac7cd4
bf124324 c014b258 c1bc07a0 c1a25000 c1ac7cf8 
Jan 12 13:43:43 borzoi user.warn kernel: 7ce0: c1ac7cec bf12438c bf1242a8
c1ac7d10 c1ac7cfc bf124504 bf12435c c1ac6000 
Jan 12 13:43:43 borzoi user.warn kernel: 7d00: c1ad8000 c1ac7dc0 c1ac7d14
c0137b88 bf1244e4 00000930 c1ad8930 00000000 
Jan 12 13:43:43 borzoi user.warn kernel: 7d20: 00000000 00000000 00000001
00000000 c0060018 c005fa74 00000000 bee88000 
Jan 12 13:43:43 borzoi user.warn kernel: 7d40: bee88000 bee87fff c027a298
c1832fb8 c1ac7d6c c1ac7d60 c0060110 c005ff5c 
Jan 12 13:43:43 borzoi user.warn kernel: 7d60: 00000000 00000000 c1ac7d90
c1ac7d90 c1ac7d7c c009f8e0 c0113888 c3466d00 
Jan 12 13:43:43 borzoi user.warn kernel: 7d80: 00000000 c1ac7db4 c1ac7d94
c007f354 c009f8cc c3466d00 c360d6c0 00000008 
Jan 12 13:43:43 borzoi user.warn kernel: 7da0: c3ae04cc c1a6f5e0 c0334ca0
c1ac6000 00000001 c1ac7dd4 c1ac7dc4 c0138028 
Jan 12 13:43:43 borzoi user.warn kernel: 7dc0: c0137384 c360d6c0 c1ac7df8
c1ac7dd8 c007f368 c0138018 c360d6c0 c03ac040 
Jan 12 13:43:43 borzoi user.warn kernel: 7de0: 00000000 c03ac040 00000000
c1ac7e0c c1ac7dfc c007f404 c007f1ec c360d6c0 
Jan 12 13:43:43 borzoi user.warn kernel: 7e00: c1ac7e28 c1ac7e10 c007d650
c007f3a4 00000001 00000000 c03ac048 c1ac7e50 
Jan 12 13:43:43 borzoi user.warn kernel: 7e20: c1ac7e2c c003a704 c007d600
c03ac040 0000000f 00000001 0000000f c35a52e0 
Jan 12 13:43:43 borzoi user.warn kernel: 7e40: 00000005 c1ac7e70 c1ac7e54
c003aec0 c003a668 c1ac6000 00000005 c1ac7e88 
Jan 12 13:43:43 borzoi user.warn kernel: 7e60: c1ac7e6c c1ac7e88 c1ac7e74
c003bb98 c003ad6c c1860614 c1860604 c1ac7ec0 
Jan 12 13:43:43 borzoi user.warn kernel: 7e80: c1ac7e8c c0046a5c c003bae4
c35a54d4 c1ac7fb0 c1ac7f60 c001bfa4 00000000 
Jan 12 13:43:43 borzoi user.warn kernel: 7ea0: c1ac7fb0 c1ac6000 c35a54d4
c1ac6000 00000005 c1ac7f9c c1ac7ec4 c0020004 
Jan 12 13:43:43 borzoi user.warn kernel: 7ec0: c0046714 c1ac7ed0 c0033a0c
c00336f0 02c76300 c1ac7f24 c1ac7ee4 c01f7504 
Jan 12 13:43:43 borzoi user.warn kernel: 7ee0: 00000009 00000000 00000000
00000000 00000000 00000000 c1ac7f28 c1ac7f24 
Jan 12 13:43:43 borzoi user.warn kernel: 7f00: c1ac7f0c c00429e8 c0042948
a0000013 800130fe 7fffffd1 c1ac7f5c c1ac7f28 
Jan 12 13:43:43 borzoi user.warn kernel: 7f20: c01f8530 c00429c0 00000000
00200200 800130fe c004389c c35a52e0 c027fdf4 
Jan 12 13:43:43 borzoi user.warn kernel: 7f40: 00ffffff 00000000 00000000
7ffff14c 00000000 7fffffd0 00000000 bee87aa4 
Jan 12 13:43:43 borzoi user.warn kernel: 7f60: 00000008 00000000 3b9aca00
c0043a24 0147ae14 bee87bb8 00000000 00000000 
Jan 12 13:43:43 borzoi user.warn kernel: 7f80: 000000a2 c001bfa4 c1ac6000
00000005 c1ac7fac c1ac7fa0 c00206e0 c001ffac 
Jan 12 13:43:43 borzoi user.warn kernel: 7fa0: 00000000 c1ac7fb0 c001be6c
c00206bc fffffdfc bee87aa4 00000000 00000008 
Jan 12 13:43:43 borzoi user.warn kernel: 7fc0: bee87bb8 00000000 00000000
bee87b38 bee87aa4 00012e94 00000005 00000001 
Jan 12 13:43:43 borzoi user.warn kernel: 7fe0: 00000000 bee87aa0 000036fc
400b8130 40000010 bee87aa4 00000000 00000000 
Jan 12 13:43:43 borzoi user.warn kernel: Backtrace: 
Jan 12 13:43:43 borzoi user.warn kernel: [<c014b24c>]
(uart_flush_buffer+0x0/0x74) from [<bf124324>] (hci_uart_flush+0x88/0xb4 [hci_uart])
Jan 12 13:43:43 borzoi user.warn kernel:  r4 = C1BC07A0 
Jan 12 13:43:43 borzoi user.warn kernel: [<bf12429c>] (hci_uart_flush+0x0/0xb4
[hci_uart]) from [<bf12438c>] (hci_uart_close+0x3c/0x44 [hci_uart])
Jan 12 13:43:43 borzoi user.warn kernel:  r5 = C1A25000  r4 = C1BC07A0 
Jan 12 13:43:43 borzoi user.warn kernel: [<bf124350>] (hci_uart_close+0x0/0x44
[hci_uart]) from [<bf124504>] (hci_uart_tty_close+0x2c/0x78 [hci_uart])
Jan 12 13:43:43 borzoi user.warn kernel: [<bf1244d8>]
(hci_uart_tty_close+0x0/0x78 [hci_uart]) from [<c0137b88>] (release_dev+0x810/0x890)
Jan 12 13:43:43 borzoi user.warn kernel:  r5 = C1AD8000  r4 = C1AC6000 
Jan 12 13:43:43 borzoi user.warn kernel: [<c0137378>] (release_dev+0x0/0x890)
from [<c0138028>] (tty_release+0x1c/0x28)
Jan 12 13:43:43 borzoi user.warn kernel: [<c013800c>] (tty_release+0x0/0x28)
from [<c007f368>] (__fput+0x188/0x1b8)
Jan 12 13:43:43 borzoi user.warn kernel:  r4 = C360D6C0 
Jan 12 13:43:43 borzoi user.warn kernel: [<c007f1e0>] (__fput+0x0/0x1b8) from
[<c007f404>] (fput+0x6c/0x9c)
Jan 12 13:43:43 borzoi user.warn kernel:  r8 = 00000000  r7 = C03AC040  r6 =
00000000  r5 = C03AC040
Jan 12 13:43:43 borzoi user.warn kernel:  r4 = C360D6C0 
Jan 12 13:43:43 borzoi user.warn kernel: [<c007f398>] (fput+0x0/0x9c) from
[<c007d650>] (filp_close+0x5c/0x88)
Jan 12 13:43:43 borzoi user.warn kernel: 0 
Jan 12 13:43:43 borzoi user.warn kernel: [<c007d5f4>] (filp_close+0x0/0x88) from
[<c003a704>] (put_files_struct+0xa8/0xe0)
Jan 12 13:43:43 borzoi user.warn kernel:  r6 = C03AC048  r5 = 00000000  r4 =
00000001 
Jan 12 13:43:43 borzoi user.warn kernel: [<c003a65c>]
(put_files_struct+0x0/0xe0) from [<c003aec0>] (do_exit+0x160/0xd40)
Jan 12 13:43:43 borzoi user.warn kernel: [<c003ad60>] (do_exit+0x0/0xd40) from
[<c003bb98>] (do_group_exit+0xc0/0xfc)
Jan 12 13:43:43 borzoi user.warn kernel: [<c003bad8>] (do_group_exit+0x0/0xfc)
from [<c0046a5c>] (get_signal_to_deliver+0x354/0x5c4)
Jan 12 13:43:43 borzoi user.warn kernel:  r5 = C1860604  r4 = C1860614 
Jan 12 13:43:43 borzoi user.warn kernel: [<c0046708>]
(get_signal_to_deliver+0x0/0x5c4) from [<c0020004>] (do_signal+0x64/0x520)
Jan 12 13:43:43 borzoi user.warn kernel: [<c001ffa0>] (do_signal+0x0/0x520) from
[<c00206e0>] (do_notify_resume+0x30/0x34)
Jan 12 13:43:43 borzoi user.warn kernel: [<c00206b0>]
(do_notify_resume+0x0/0x34) from [<c001be6c>] (work_pending+0x1c/0x20)
Jan 12 13:43:43 borzoi user.warn kernel: Code: e2833001 e5823004 e59c1010
e3a03000 (e5813008) 
Jan 12 13:43:43 borzoi user.warn kernel:  <1>Fixing recursive fault but reboot
is needed!
Jan 12 13:43:43 borzoi user.err kernel: scheduling while atomic:
hciattach/0x00000002/3203
Jan 12 13:43:43 borzoi user.warn kernel: [<c002179c>] (dump_stack+0x0/0x14) from
[<c01f7680>] (schedule+0x620/0x6bc)
Jan 12 13:43:43 borzoi user.warn kernel: [<c01f7060>] (schedule+0x0/0x6bc) from
[<c003b968>] (do_exit+0xc08/0xd40)
Jan 12 13:43:43 borzoi user.warn kernel: [<c003ad60>] (do_exit+0x0/0xd40) from
[<c0021ad4>] (die+0x2dc/0x3ac)
Jan 12 13:43:43 borzoi user.warn kernel: [<c00217f8>] (die+0x0/0x3ac) from
[<c00241b8>] (__do_kernel_fault+0x70/0x80)
Jan 12 13:43:43 borzoi user.warn kernel: [<c0024148>]
(__do_kernel_fault+0x0/0x80) from [<c002444c>] (do_page_fault+0x1c0/0x214)
Jan 12 13:43:43 borzoi user.warn kernel:  r7 = 00000008  r6 = C0232220  r5 =
00000817  r4 = C02321B0
Jan 12 13:43:43 borzoi user.warn kernel: [<c002428c>] (do_page_fault+0x0/0x214)
from [<c00245dc>] (do_DataAbort+0x3c/0xa4)
Jan 12 13:43:43 borzoi user.warn kernel: [<c00245a0>] (do_DataAbort+0x0/0xa4)
from [<c001b9c0>] (__dabt_svc+0x40/0x60)
Jan 12 13:43:43 borzoi user.warn kernel:  r8 = 00000000  r7 = 00000000  r6 =
00000000  r5 = C1AC7CAC
Jan 12 13:43:43 borzoi user.warn kernel:  r4 = FFFFFFFF 
Jan 12 13:43:43 borzoi user.warn kernel: [<c014b24c>]
(uart_flush_buffer+0x0/0x74) from [<bf124324>] (hci_uart_flush+0x88/0xb4 [hci_uart])
Jan 12 13:43:43 borzoi user.warn kernel:  r4 = C1BC07A0 
Jan 12 13:43:43 borzoi user.warn kernel: [<bf12429c>] (hci_uart_flush+0x0/0xb4
[hci_uart]) from [<bf12438c>] (hci_uart_close+0x3c/0x44 [hci_uart])
Jan 12 13:43:43 borzoi user.warn kernel:  r5 = C1A25000  r4 = C1BC07A0 
Jan 12 13:43:43 borzoi user.warn kernel: [<bf124350>] (hci_uart_close+0x0/0x44
[hci_uart]) from [<bf124504>] (hci_uart_tty_close+0x2c/0x78 [hci_uart])
Jan 12 13:43:43 borzoi user.warn kernel: [<bf1244d8>]
(hci_uart_tty_close+0x0/0x78 [hci_uart]) from [<c0137b88>] (release_dev+0x810/0x890)
Jan 12 13:43:43 borzoi user.warn kernel:  r5 = C1AD8000  r4 = C1AC6000 
Jan 12 13:43:43 borzoi user.warn kernel: [<c0137378>] (release_dev+0x0/0x890)
from [<c0138028>] (tty_release+0x1c/0x28)
Jan 12 13:43:43 borzoi user.warn kernel: [<c013800c>] (tty_release+0x0/0x28)
from [<c007f368>] (__fput+0x188/0x1b8)
Jan 12 13:43:43 borzoi user.warn kernel:  r4 = C360D6C0 
Jan 12 13:43:43 borzoi user.warn kernel: [<c007f1e0>] (__fput+0x0/0x1b8) from
[<c007f404>] (fput+0x6c/0x9c)
Jan 12 13:43:43 borzoi user.warn kernel:  r8 = 00000000  r7 = C03AC040  r6 =
00000000  r5 = C03AC040
Jan 12 13:43:43 borzoi user.warn kernel:  r4 = C360D6C0 
Jan 12 13:43:43 borzoi user.warn kernel: [<c007f398>] (fput+0x0/0x9c) from
[<c007d650>] (filp_close+0x5c/0x88)
Jan 12 13:43:43 borzoi user.warn kernel:  r4 = C360D6C0 
Jan 12 13:43:43 borzoi user.warn kernel: [<c007d5f4>] (filp_close+0x0/0x88) from
[<c003a704>] (put_files_struct+0xa8/0xe0)
Jan 12 13:43:43 borzoi user.warn kernel:  r6 = C03AC048  r5 = 00000000  r4 =
00000001 
Jan 12 13:43:43 borzoi user.warn kernel: [<c003a65c>]
(put_files_struct+0x0/0xe0) from [<c003aec0>] (do_exit+0x160/0xd40)
Jan 12 13:43:43 borzoi user.warn kernel: [<c003ad60>] (do_exit+0x0/0xd40) from
[<c003bb98>] (do_group_exit+0xc0/0xfc)
Jan 12 13:43:43 borzoi user.warn kernel: [<c003bad8>] (do_group_exit+0x0/0xfc)
from [<c0046a5c>] (get_signal_to_deliver+0x354/0x5c4)
Jan 12 13:43:43 borzoi user.warn kernel:  r5 = C1860604  r4 = C1860614 
Jan 12 13:43:43 borzoi user.warn kernel: [<c0046708>]
(get_signal_to_deliver+0x0/0x5c4) from [<c0020004>] (do_signal+0x64/0x520)
Jan 12 13:43:43 borzoi user.warn kernel: [<c001ffa0>] (do_signal+0x0/0x520) from
[<c00206e0>] (do_notify_resume+0x30/0x34)
Jan 12 13:43:43 borzoi user.warn kernel: [<c00206b0>]
(do_notify_resume+0x0/0x34) from [<c001be6c>] (work_pending+0x1c/0x20)
Jan 12 13:43:44 borzoi daemon.info cardmgr[2576]: executing: 'modprobe -r
serial_cs'