From: Russell King <rmk@arm.linux.org.uk>
To: Linux Kernel List <linux-kernel@vger.kernel.org>
Cc: Patrick Mochel <mochel@osdl.org>,
Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
Jeff Garzik <jgarzik@pobox.com>, Greg KH <greg@kroah.com>,
Rusty Russell <rusty@rustcorp.com.au>
Subject: PCI driver module unload race?
Date: Sat, 8 Mar 2003 10:47:49 +0000 [thread overview]
Message-ID: <20030308104749.A29145@flint.arm.linux.org.uk> (raw)
Hi,
What prevents the following scenario from happening? It's purely
theoretical - I haven't seen this occuring.
- Load PCI driver.
- PCI driver registers using pci_module_init(), and adds itself to sysfs.
- Hot-plugin a PCI device which uses this driver. sysfs matches the PCI
driver, and calls the PCI drivers probe function.
- The probe function calls kmalloc or some other function which sleeps
(or gets preempted, if CONFIG_PREEMPT is enabled.)
- We switch to another thread, which happens to be rmmod for this PCI
driver. We remove the driver since it has a use count of zero.
- We switch back to the PCI driver. Oops.
I've probably missed something, but I don't think so. I suspect we need
struct device_driver to include a struct module pointer which sysfs can
take before calling any driver functions.
Comments?
--
Russell King (rmk@arm.linux.org.uk) The developer of ARM Linux
http://www.arm.linux.org.uk/personal/aboutme.html
next reply other threads:[~2003-03-08 19:53 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-03-08 10:47 Russell King [this message]
2003-03-08 19:12 ` PCI driver module unload race? Greg KH
2003-03-08 19:47 ` Petr Vandrovec
2003-03-08 19:51 ` Greg KH
2003-03-09 2:33 ` Petr Vandrovec
2003-03-08 20:03 ` Russell King
2003-03-08 20:09 ` Russell King
2003-03-08 20:21 ` Greg KH
2003-03-10 21:44 ` Greg KH
2003-03-10 23:48 ` Oliver Neukum
2003-03-10 23:51 ` Greg KH
2003-03-11 1:04 ` Roman Zippel
2003-03-11 1:15 ` Greg KH
2003-03-11 9:00 ` Oliver Neukum
2003-03-11 15:06 ` Patrick Mochel
2003-03-11 16:07 ` Oliver Neukum
2003-03-16 13:13 ` Rusty Russell
2003-03-11 11:05 ` Roman Zippel
2003-03-11 15:27 ` Patrick Mochel
2003-03-11 20:09 ` Roman Zippel
2003-03-11 19:15 ` Patrick Mochel
2003-03-12 2:28 ` Roman Zippel
2003-03-16 13:05 ` Rusty Russell
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