Re: [RFC][Patch 1/4] kprobe fast unregistration

[Christoph Hellwig <hch@infradead.org>]

On Fri, Mar 23, 2007 at 11:43:48PM +0900, Masami Hiramatsu wrote:
> I'd like to suggest introducing following two interfaces for this issue.
> The first interface is unregister_*probe_fast(). This removes
> breakpoint instruction from kernel code and adds specified probe
> to the unregistering list.
> The second interface is commit_kprobes(). This waits the rcu
> synchronization and clean up each probe on the unregistering list.
> This patch also adds a list_head member to the kprobe data structure
> for linking to the unregistering list.
> 
> If using these interfaces, the probe handlers of unregistering probes
> might be called after unregister_*probe_fast() is called. So, you MUST
> call commit_kprobes() after calling unregisnter_*probe_fast() for all
> probes.

Speeding up the unregistration is a very good idea, but this interface
is rather horrible.  It's almost a receipe for users to get it wrong.

Instead just changes the register and unregister functions to take
a NULL-terminated array of probes that get registered and unregisters
at the same time (and renames them from *probe* to *probes*, please)