Re: [PATCH] sysfs: Don't block indefinitely for unmapped files.

From: Tejun Heo
Date: Wed Feb 25 2009 - 04:16:22 EST


Hello, Eric.

Eric W. Biederman wrote:
> This patch modifies sysfs bin files so that we can remove
> the bin file while they are still mapped. When the kobject
> is removed we unmap the bin file and arrange for future
> accesses to the mapping to receive SIGBUS.
>
> Implementing this prevents a nasty DOS when pci devices are
> hot plugged and unplugged. Where if any of their resources
> were mmaped the kernel could not free up their pci resources
> or release their pci data structures.
>
> Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxxxxxxxx>

Heh... this is so cool. I've never thought about it. I would really
like more comments but other than that

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

--
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/