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From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Helge Deller <deller@gmx.de>,
	linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
	linux-arch@vger.kernel.org,
	"James E.J. Bottomley" <jejb@parisc-linux.org>,
	linux-parisc@vger.kernel.org
Subject: Re: [PATCH repost 12/16] parisc/uaccess: fix sparse errors
Date: Wed, 31 Dec 2014 12:23:26 -0800	[thread overview]
Message-ID: <1420057406.2085.7.camel@HansenPartnership.com> (raw)
In-Reply-To: <20141231183824.GA32430@redhat.com>

On Wed, 2014-12-31 at 20:38 +0200, Michael S. Tsirkin wrote:
> On Wed, Dec 31, 2014 at 09:17:20AM -0800, James Bottomley wrote:
[...]
> > OK, parisc developers still being dense, but this does look like an
> > abuse of the bitwise type.
> 
> To give you another example:
> 
> 	__le16 __user *p;
> 	__le16 foo;
> 	int rc = get_user(v, p);
> 
> really should be fine, ATM this gives a warning.

OK, I think I've figured it out.  You're saying that casting __gu_val to
a bitwise annotated type is an automatic sparse failure because it has
to be a long in our assembly code to receive the load/store as a
register.  However, this is required for sparse to do the correct lvalue
type = rvalue type check in the assignment to x.  We were all thinking
the __force just killed these sparse type checks.

In that case, I think parisc is fine with this.

James



  reply	other threads:[~2014-12-31 20:23 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-25  9:28 [PATCH repost 00/16] uaccess: fix sparse warning on get_user for bitwise types Michael S. Tsirkin
2014-12-25  9:28 ` [PATCH repost 01/16] x86/uaccess: fix sparse errors Michael S. Tsirkin
2014-12-25  9:28 ` [PATCH repost 02/16] alpha/uaccess: " Michael S. Tsirkin
2014-12-25  9:28   ` Michael S. Tsirkin
2014-12-25  9:28 ` [PATCH repost 03/16] arm64/uaccess: " Michael S. Tsirkin
2015-01-23 15:33   ` Catalin Marinas
2015-01-23 15:42     ` Will Deacon
2015-01-23 16:35       ` Catalin Marinas
2015-01-23 16:35         ` Catalin Marinas
2014-12-25  9:28 ` [PATCH repost 04/16] avr32/uaccess: " Michael S. Tsirkin
2014-12-25  9:28   ` Michael S. Tsirkin
2014-12-25  9:28 ` [PATCH repost 05/16] blackfin/uaccess: " Michael S. Tsirkin
2014-12-25  9:28   ` Michael S. Tsirkin
2014-12-25  9:28 ` [PATCH repost 06/16] cris/uaccess: " Michael S. Tsirkin
2014-12-25  9:28   ` Michael S. Tsirkin
2014-12-25  9:28 ` [PATCH repost 07/16] ia64/uaccess: " Michael S. Tsirkin
2014-12-25  9:28   ` Michael S. Tsirkin
2014-12-25  9:28 ` [PATCH repost 08/16] m32r/uaccess: " Michael S. Tsirkin
2014-12-25  9:28   ` Michael S. Tsirkin
2014-12-25  9:29 ` [PATCH repost 09/16] metag/uaccess: " Michael S. Tsirkin
2014-12-25  9:29   ` Michael S. Tsirkin
2015-01-02 15:41   ` James Hogan
2015-01-02 15:41     ` James Hogan
2015-01-04 10:52     ` Michael S. Tsirkin
2015-01-05  9:44       ` James Hogan
2015-01-05  9:44         ` James Hogan
2015-01-05 13:00         ` Michael S. Tsirkin
2015-01-05 13:00           ` Michael S. Tsirkin
2015-01-05 14:47           ` James Hogan
2015-01-06 10:00             ` Michael S. Tsirkin
2014-12-25  9:29 ` [PATCH repost 10/16] microblaze/uaccess: " Michael S. Tsirkin
2014-12-25  9:29 ` [PATCH repost 11/16] openrisc/uaccess: " Michael S. Tsirkin
2014-12-25  9:29   ` Michael S. Tsirkin
2014-12-25  9:29 ` [PATCH repost 12/16] parisc/uaccess: " Michael S. Tsirkin
2014-12-25  9:29   ` Michael S. Tsirkin
2014-12-25 22:37   ` Helge Deller
2014-12-27 16:14     ` Michael S. Tsirkin
2014-12-31 17:17       ` James Bottomley
2014-12-31 18:38         ` Michael S. Tsirkin
2014-12-31 20:23           ` James Bottomley [this message]
2014-12-31 20:23             ` James Bottomley
2014-12-25  9:29 ` [PATCH repost 13/16] sh/uaccess: " Michael S. Tsirkin
2014-12-25  9:29   ` Michael S. Tsirkin
2014-12-25  9:29 ` [PATCH repost 14/16] sparc/uaccess: " Michael S. Tsirkin
2014-12-25  9:30 ` [PATCH repost 15/16] " Michael S. Tsirkin
2014-12-25 23:39   ` David Miller
2014-12-28 10:21     ` Michael S. Tsirkin
2014-12-25  9:30 ` [PATCH repost 16/16] m68k/uaccess: " Michael S. Tsirkin

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