Messages in this thread | | | Date | Thu, 20 Jul 2017 16:45:24 +0200 (CEST) | From | Miroslav Benes <> | Subject | Re: [PATCH v2 1/2] livepatch: introduce shadow variable API |
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> > > > + * > > > > + * Note: allocates @new_size space for shadow variable data and copies > > > > + * @new_size bytes from @new_data into the shadow varaible's own @new_data > > > > + * space. If @new_data is NULL, @new_size is still allocated, but no > > > > + * copy is performed. > > > > > > I must say I'm not entirely happy with this. I don't know if this is what > > > Petr had in mind (I'm sure he'll get to the patch set soon). Calling > > > memcpy instead of a simple assignment in v1 seems worse. > > > > This change was a bit of a experiment on my part in reaction to > > adding klp_shadow_get_or_attach(). > > > > I like the simplicity of v1's pointer assignment -- in fact, moving all > > allocation responsiblity (klp_shadow meta-data and data[] area) out to > > the caller is doable, though implementing klp_shadow_get_or_attach() and > > and klp_shadow_detach_all() complicates matters, for example, adding an > > alloc/release callback. I originally attempted this for v2, but turned > > back when the API and implementation grew complicated. If the memcpy > > and gfp_flag restrictions are too ugly, I can try revisting that > > approach. Ideas welcome :) > > Well, I didn't like callbacks either :). And no, I do not have a better > idea. I still need to think about it.
Done and I agree that memcpy approach is not so bad after all :). So I'm fine with it.
Miroslav
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