Subject: Re: linux-next: build warning after merge of the rcu tree

From: Jonathan Corbet <[email-masked]>
Date: Mon, 7 Dec 2020 10:48:51 -0700

On Mon, 7 Dec 2020 08:47:04 -0800
"Paul E. McKenney" <[email-masked]> wrote:

> I freely confess that I have absolutely no idea what it doesn't like.
> It is complaining about this header comment, correct?
> 
> /**
>  * kmem_last_alloc_stack - Get return address and stack for last allocation
>  * @object: object for which to find last-allocation return address.
>  * @stackp: %NULL or pointer to location to place return-address stack.
>  * @nstackp: maximum number of return addresses that may be stored.
>  *
>  * If the pointer references a slab-allocated object and if sufficient
>  * debugging is enabled, return the return address for the corresponding
>  * allocation.  If stackp is non-%NULL in %CONFIG_STACKTRACE kernels running
>  * the slub allocator, also copy the return-address stack into @stackp,
>  * limited by @nstackp.  Otherwise, return %NULL or an appropriate error
>  * code using %ERR_PTR().
>  *
>  * Return: return address from last allocation, %NULL or negative error code.
>  */

The problem is the %ERR_PTR().  I'm honestly not quite sure why, Sphinx is
being a little weird there.  But in any case the % notation is supposed to
mark a constant, which is not the case here.  I'd just take the % signs
out.

jon