On Wed, Dec 12, 2012 at 02:56:47AM +0100, Hans J. Koch wrote: > On Tue, Dec 11, 2012 at 03:18:16PM -0800, Greg KH wrote: > > On Wed, Dec 12, 2012 at 12:12:01AM +0100, Benedikt Spranger wrote: > > > The documentation has no clear statement to the POSIX 1003.1 mmap() > > > feature, wich allows open(), mmap(), close() while the mmaped pointer is > > > valid. > > > The release() hook inveigled driver programmer to activate owermanagement > > > functuonality in the release hook. This may harm. > > > > > > Signed-off-by: Benedikt Spranger <b.spran...@linutronix.de> > > > --- > > > Documentation/DocBook/uio-howto.tmpl | 7 ++++++- > > > 1 file changed, 6 insertions(+), 1 deletion(-) > > > > > > diff --git a/Documentation/DocBook/uio-howto.tmpl > > > b/Documentation/DocBook/uio-howto.tmpl > > > index ac3d001..59a886d 100644 > > > --- a/Documentation/DocBook/uio-howto.tmpl > > > +++ b/Documentation/DocBook/uio-howto.tmpl > > > @@ -499,8 +499,13 @@ device is actually used. > > > <listitem><para> > > > <varname>int (*release)(struct uio_info *info, struct inode *inode) > > > </varname>: Optional. If you define your own > > > -<function>open()</function>, you will probably also want a custom > > > +<function>release()</function>, you will probably also want a custom > > > <function>release()</function> function. > > > > That sentance no longer makes sense. > > > > > +</para><para>CAVE: The release hook may be processed, even if a mmap is > > > aktive. > > > > Huh? > > I think that's right. You can successfully close() a device while userspace > is still > using a mapping. If the driver doesn't prevent it, userspace will fail with a > SIGBUS > when accessing the mapping the next time.
I understand mmap(), I was referring to the language of the wording :) thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
