Re: crypto: hisilicon - Fix warning on printing %p with dma_addr_t

From: "Ondrej Mosnáček" <omosnacek@gmail.com>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Zhou Wang <wangzhou1@hisilicon.com>, linux-crypto@vger.kernel.org
Subject: Re: crypto: hisilicon - Fix warning on printing %p with dma_addr_t
Date: Fri, 16 Aug 2019 09:02:27 +0200	[thread overview]
Message-ID: <CAAUqJDsvG-c=svGzszE8nCXwjGSYUa9BB1Jj0srY+_rX0X-jyw@mail.gmail.com> (raw)
In-Reply-To: <20190815224207.GA3047@gondor.apana.org.au>

Hi Herbert,

pi 16. 8. 2019 o 1:52 Herbert Xu <herbert@gondor.apana.org.au> napísal(a):
> On Thu, Aug 15, 2019 at 10:17:37PM +0800, Zhou Wang wrote:
> >
> > > -   dev_dbg(&qm->pdev->dev, "QM mailbox request to q%u: %u-%pad\n", queue,
> > > -           cmd, dma_addr);
> > > +   dev_dbg(&qm->pdev->dev, "QM mailbox request to q%u: %u-%#lxad\n",
> > > +           queue, cmd, (unsigned long)dma_addr);
> >
> > Thanks. However, to be honest I can't get why we fix it like this.
> > Can you give me a clue?
>
> dma_addr_t is not a pointer.  It's an integer type and therefore
> you need to print it out as such.

According to Documentation/core-api/printk-formats.rst, %pad is the
format specifier intended specifically for dma_addr_t [1], so perhaps
the kbuild robot warning was in fact bogus?

[1] https://www.kernel.org/doc/html/latest/core-api/printk-formats.html#dma-address-types-dma-addr-t

>
> Actually my patch is buggy too, on some architectures it can be
> a long long so we need to cast is such.
>
> Cheers,
> --
> Email: Herbert Xu <herbert@gondor.apana.org.au>
> Home Page: http://gondor.apana.org.au/~herbert/
> PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt