Re: [patch 1/2] debugobjects: extend debugobjects to assert that anobject is initialized

From: Thomas Gleixner
Date: Wed Sep 21 2011 - 04:28:12 EST


On Tue, 20 Sep 2011, akpm@xxxxxxxxxx wrote:

Back to LKML

> From: Christine Chan <cschan@xxxxxxxxxxxxxx>
> Subject: debugobjects: extend debugobjects to assert that an object is initialized
>
> Add new check (assert_init) to make sure objects are initialized and
> tracked by debugobjects.

When is this function to be called and what problem does it solve
which is not handled by the current code?

> + int (*fixup_assert_init)(void *addr, enum debug_obj_state state);
> };
>
> /**
> + * debug_object_assert_init - debug checks when object should be init-ed
> + * @addr: address of the object
> + * @descr: pointer to an object specific debug description structure
> + */
> +void debug_object_assert_init(void *addr, struct debug_obj_descr *descr)
> +{
> + struct debug_bucket *db;
> + struct debug_obj *obj;
> + unsigned long flags;
> +
> + if (!debug_objects_enabled)
> + return;
> +
> + db = get_bucket((unsigned long) addr);
> +
> + raw_spin_lock_irqsave(&db->lock, flags);
> +
> + obj = lookup_object(addr, db);
> + if (!obj) {
> + raw_spin_unlock_irqrestore(&db->lock, flags);
> + /*
> + * Maybe the object is static. Let the type specific
> + * code decide what to do.
> + */
> + debug_object_fixup(descr->fixup_assert_init, addr,
> + ODEBUG_STATE_NOTAVAILABLE);

So what's the point of requiring that function to return a value when
it's unchecked?

Thanks,

tglx
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