[PATCH 3/4] driver/memmap: fix generic_memmap_rw and generic_memmap_ro

[Sascha Hauer]

On Thu, Feb 10, 2011 at 12:50:14PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> On 08:12 Thu 10 Feb     , Sascha Hauer wrote:
> > On Thu, Feb 10, 2011 at 04:31:59AM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > > we check before the RW access for generic_memmap_ro instead of
> > > generic_memmap_rw
> > > 
> > > Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
> > > ---
> > >  drivers/base/driver.c |    5 +++--
> > >  1 files changed, 3 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/base/driver.c b/drivers/base/driver.c
> > > index ff92e44..bd7464e 100644
> > > --- a/drivers/base/driver.c
> > > +++ b/drivers/base/driver.c
> > > @@ -223,8 +223,6 @@ int generic_memmap_ro(struct cdev *cdev, void **map, int flags)
> > >  	if (!cdev->dev)
> > >  		return -EINVAL;
> > >  
> > > -	if (flags & PROT_WRITE)
> > > -		return -EACCES;
> > >  	*map = (void *)cdev->dev->map_base;
> > >  	return 0;
> > >  }
> > > @@ -234,6 +232,9 @@ int generic_memmap_rw(struct cdev *cdev, void **map, int flags)
> > >  	if (!cdev->dev)
> > >  		return -EINVAL;
> > >  
> > > +	if (flags & PROT_WRITE)
> > > +		return -EACCES;
> > > +
> > 
> > So instead of allowing write access in the read/write function we now
> > allow it in the readonly function? I'm afraid I don't understand this.
> PROT_WRITE means ro no?

No. The semantics are from mmap(2):

	PROT_EXEC  Pages may be executed.

	PROT_READ  Pages may be read.

	PROT_WRITE Pages may be written.

	PROT_NONE  Pages may not be accessed.

Sascha

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