Messages in this thread | | | Date | Fri, 18 Aug 2017 11:42:50 +0200 | From | Petr Mladek <> | Subject | Re: [PATCH v4] livepatch: introduce shadow variable API |
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On Thu 2017-08-17 12:01:33, Joe Lawrence wrote: > On 08/17/2017 10:05 AM, Petr Mladek wrote: > >> diff --git a/kernel/livepatch/shadow.c b/kernel/livepatch/shadow.c > >> new file mode 100644 > >> index 000000000000..0ebd4b635e4f > >> --- /dev/null > >> +++ b/kernel/livepatch/shadow.c > >> +/** > >> + * klp_shadow_match() - verify a shadow variable matches given <obj, id> > >> + * @shadow: shadow variable to match > >> + * @obj: pointer to parent object > >> + * @id: data identifier > >> + * > >> + * Return: true if the shadow variable matches. > >> + * > >> + * Callers should hold the klp_shadow_lock. > >> + */ > >> +static inline bool klp_shadow_match(struct klp_shadow *shadow, void *obj, > >> + unsigned long id) > >> +{ > >> + return shadow->obj == obj && shadow->id == id; > >> +} > > > > Do we really need this function? It is called only in situations > > where shadow->obj == obj is always true. Especially the use in > > klp_shadow_detach_all() is funny because we pass shadow->obj as > > the shadow parameter. > > Personal preference. Abstracting out all of the routines that operated > on the shadow variables (setting up, comparison) did save some code > lines and centralized these common bits.
I take this back. We actually need to check obj because different objects might have the same hash.
I think that I did the same mistake also the last time. I hope that I will be able to fix this in my mind faster than "never" vs. "newer" typo that I do for years.
Also I forgot to say that you did great work. Each version of the patch is much better than the previous one.
Best Regards, Petr
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