From: Simon Kelley <simon@thekelleys.org.uk>
To: linux-hotplug@vger.kernel.org
Subject: Bad karma with re-entrant hotplug scripts - please advise.
Date: Thu, 05 Feb 2004 22:19:21 +0000 [thread overview]
Message-ID: <4022C169.4090502@thekelleys.org.uk> (raw)
When using the hotplug system to configure a network interface which
uses the Atmel wireless driver, the following sequence occurs.
1) Interface comes up: /sbin/hotplug is run which eventually runs
/etc/hotplug/net.agent
2) net.agent brings up interface which eventually calls open() routine
in driver.
3) open routine in driver calls request_firmware() which causes a second
invocation of /sbin/hotplug which then invokes /etc/hotplug/firmware.agent
4) Depending on the exact context, either this all works, or the
following oops happens:
Unable to handle kernel NULL pointer dereference at virtual address 00000020
printing eip:
c0162ec2
*pde = 00000000
Oops: 0000 [#1]
CPU: 0
0060:[<c0162ec2>] Not tainted
EFLAGS: 00010246
EIP is at dnotify_flush+0x12/0xa0
eax: c1ec3840 ebx: c1f0b0c0 ecx: c1f0b0c0 edx: 00000000
esi: c1e6f240 edi: c1f0b0c0 ebp: c1f6ff78 esp: c1f6ff6c
ds: 007b es: 007b ss: 0068
Process firmware.agent (pid: 500, threadinfo¡f6e000 task¡f246c0)
Stack: c1f0b0c0 00000000 c1e6f240 c1f6ff94 c0148a16 c1f0b0c0 c1e6f240
0000001
c1f6e000 c1f0bca0 c1f6ffbc c01599cb c1f0b0c0 c1e6f240 c1e6f240 c1f0b0c0
fffffff0 0000000a 0000000a 00000007 c1f6e000 c0108f97 0000000a 00000001
Call Trace:
[<c0148a16>] filp_close+0x36/0x70
[<c01599cb>] sys_dup2+0xcb/0x130
[<c0108f97>] syscall_call+0x7/0xb
Code: 66 8b 42 20 25 00 f0 00 00 3d 00 40 00 00 74 0e 8d 65 f4 5b
or all hell breaks loose and the kernel oopes over and over again before
finally dying in an interrupt handler.
Can anybody who is familiar with the code tell me is the above should
work, what the likeley problem might be, and how to try and fix it?
If I can't solve this I'll be forced to get the firmware image when the
interface is created and keep it around for the life of the interface,
rather then calling request_firmware whenever the firmware is needed,
but that kind of defeats the purpose of the firmware request interface.
Cheers,
Simon.
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next reply other threads:[~2004-02-05 22:19 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-02-05 22:19 Simon Kelley [this message]
2004-02-06 0:09 ` Bad karma with re-entrant hotplug scripts - please advise Greg KH
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