Re: oops in uevent_helper [was: mmotm 2010-01-13-12-17 uploaded]

[Jiri Slaby <jirislaby@gmail.com>]

On 02/12/2010 06:06 PM, Neil Horman wrote:
> Fix up remaining references to uevent_helper to play nice with Andi's
> uevent_helper/rcu changes.
> 
> Some changes were made recently which modified uevent_helper to be an rcu
> protected pointer, rather than a static char array.  This has led to a few
> missed points in which the sysfs path still assumed that:
> 1) the uevent_helper symbol could still be accessed safely without
> rcu_dereference
> 2) that the sysfs path could copy data to that pointer safely.
> 
> I've fixed this by chaging the sysfs path so that it duplicates the string on
> uevent_helper_store, and freeing it (only if it doesn't point to the
> CONFIG_DEFAULT_UEVENT_HELPER string), in a call_rcu post-quiescent point.  I've
> also fixed up the remaining references to the uevent_helper pointers to use
> rcu_dereference.
> 
> Signed-off-by: Neil Horman <nhorman@tuxdriver.com>

Tested-by: Jiri Slaby <jirislaby@gmail.com>

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