From: hch@infradead.org (Christoph Hellwig)
Subject: [PATCH] nvme: fix 32-bit build warning
Date: Fri, 9 Oct 2015 07:42:21 -0700 [thread overview]
Message-ID: <20151009144221.GA12760@infradead.org> (raw)
In-Reply-To: <5851501.PBMrs03XFb@wuerfel>
On Tue, Oct 06, 2015@10:37:11PM +0200, Arnd Bergmann wrote:
> Compiling the nvme driver on 32-bit warns about a cast from a __u64
> variable to a pointer:
>
> drivers/block/nvme-core.c: In function 'nvme_submit_io':
> drivers/block/nvme-core.c:1847:4: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
> (void __user *)io.addr, length, NULL, 0);
>
> The cast here is intentional and safe, so we can shut up the
> gcc warning by adding an intermediate cast to 'unsigned long'.
It really should be a uintptr_t, which would also avoid the > 80
character lines. I wonder if we need a u64_to_ptr helper given these
ioctl ABIs that pass pointers as a u64 seems to be everywhere these
days.
WARNING: multiple messages have this Message-ID (diff)
From: hch@infradead.org (Christoph Hellwig)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] nvme: fix 32-bit build warning
Date: Fri, 9 Oct 2015 07:42:21 -0700 [thread overview]
Message-ID: <20151009144221.GA12760@infradead.org> (raw)
In-Reply-To: <5851501.PBMrs03XFb@wuerfel>
On Tue, Oct 06, 2015 at 10:37:11PM +0200, Arnd Bergmann wrote:
> Compiling the nvme driver on 32-bit warns about a cast from a __u64
> variable to a pointer:
>
> drivers/block/nvme-core.c: In function 'nvme_submit_io':
> drivers/block/nvme-core.c:1847:4: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
> (void __user *)io.addr, length, NULL, 0);
>
> The cast here is intentional and safe, so we can shut up the
> gcc warning by adding an intermediate cast to 'unsigned long'.
It really should be a uintptr_t, which would also avoid the > 80
character lines. I wonder if we need a u64_to_ptr helper given these
ioctl ABIs that pass pointers as a u64 seems to be everywhere these
days.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@infradead.org>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox <willy@linux.intel.com>, Jens Axboe <axboe@fb.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org,
Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH] nvme: fix 32-bit build warning
Date: Fri, 9 Oct 2015 07:42:21 -0700 [thread overview]
Message-ID: <20151009144221.GA12760@infradead.org> (raw)
In-Reply-To: <5851501.PBMrs03XFb@wuerfel>
On Tue, Oct 06, 2015 at 10:37:11PM +0200, Arnd Bergmann wrote:
> Compiling the nvme driver on 32-bit warns about a cast from a __u64
> variable to a pointer:
>
> drivers/block/nvme-core.c: In function 'nvme_submit_io':
> drivers/block/nvme-core.c:1847:4: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
> (void __user *)io.addr, length, NULL, 0);
>
> The cast here is intentional and safe, so we can shut up the
> gcc warning by adding an intermediate cast to 'unsigned long'.
It really should be a uintptr_t, which would also avoid the > 80
character lines. I wonder if we need a u64_to_ptr helper given these
ioctl ABIs that pass pointers as a u64 seems to be everywhere these
days.
next prev parent reply other threads:[~2015-10-09 14:42 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-06 20:37 [PATCH] nvme: fix 32-bit build warning Arnd Bergmann
2015-10-06 20:37 ` Arnd Bergmann
2015-10-06 20:37 ` Arnd Bergmann
2015-10-09 14:42 ` Christoph Hellwig [this message]
2015-10-09 14:42 ` Christoph Hellwig
2015-10-09 14:42 ` Christoph Hellwig
2015-10-09 18:55 ` Arnd Bergmann
2015-10-09 18:55 ` Arnd Bergmann
2015-10-09 18:55 ` Arnd Bergmann
2015-10-09 18:58 ` [PATCH v2] " Arnd Bergmann
2015-10-09 18:58 ` Arnd Bergmann
2015-10-09 18:58 ` Arnd Bergmann
2015-10-12 19:03 ` Christoph Hellwig
2015-10-12 19:03 ` Christoph Hellwig
2015-10-12 19:03 ` Christoph Hellwig
2015-10-12 19:10 ` Jens Axboe
2015-10-12 19:10 ` Jens Axboe
2015-10-12 19:10 ` Jens Axboe
2015-10-12 19:14 ` Arnd Bergmann
2015-10-12 19:14 ` Arnd Bergmann
2015-10-12 19:14 ` Arnd Bergmann
2015-10-12 19:22 ` Jens Axboe
2015-10-12 19:22 ` Jens Axboe
2015-10-12 19:22 ` Jens Axboe
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