[lkml]   [2001]   [Apr]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: module load/unload race protection?
On Sat, Apr 14, 2001 at 12:26:40PM +0200, Mikael Pettersson wrote:
> Does the kernel's module loader (kernel/module.c, not kmod)
> protect adequately against concurrent load/load or load/unload
> requests? The question applies to both 2.2 and 2.4 kernels.
> I'm trying to track down a problem where a user using a
> RedHat 2.2.17-14 SMP kernel managed to trigger a situation where
> a driver module had been unloaded while still being in use
> (as in "the kernel has pointers into it", not USE_COUNT != 0).
> I'm reviewing the driver's internal INC/DEC_USE_COUNT usage,
> but so far I've not found any obvious errors.
> /Mikael

There are race conditions while module unloading, present in both 2.2 and 2.4
kernels. Efforts are being made in handling these races by using
read-copy-update mechanism (
and by using synchronize_kernel() (from Rusty Russell, Keith Owens).


Maneesh Soni <>
IBM Linux Technology Center,
IBM Software Lab, Bangalore, India
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:25    [W:0.054 / U:1.604 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site