Re: [PATCH v2 1/2] uio: provide vm access to UIO_MEM_PHYS maps

Re: [PATCH v2 1/2] uio: provide vm access to UIO_MEM_PHYS maps

[Uwe Kleine-König]

[expanding Cc: to also include akpm and linux-mm]

Hello,

On Mon, Jul 29, 2013 at 01:09:14PM -0700, Greg Kroah-Hartman wrote:
> On Sun, Jul 28, 2013 at 12:09:37AM +0200, Uwe Kleine-Konig wrote:
> > This makes it possible to let gdb access mappings of the process that is
> > being debugged.
> > 
> > uio_mmap_logical was moved and uio_vm_ops renamed to group related code
> > and differentiate to new stuff.
> > 
> > Signed-off-by: Uwe Kleine-Konig <u.kleine-koenig@pengutronix.de>
> > ---
> > Changes since v1:
> >     - only use generic_access_phys ifdef CONFIG_HAVE_IOREMAP_PROT
> >     - fix all users of renamed struct
> 
> I still get a build error with this patch:
> 
>   MODPOST 384 modules
> ERROR: "generic_access_phys" [drivers/uio/uio.ko] undefined!
> 
> So something isn't quite right.
Ah, you built as a module and generic_access_phys isn't exported. The
other users of generic_access_phys (arch/x86/pci/i386.c and
drivers/char/mem.c) can only be builtin.

So the IMHO best option is to add an EXPORT_SYMBOL(generic_access_phys)
to mm/memory.c.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-Konig            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

Re: [PATCH v2 1/2] uio: provide vm access to UIO_MEM_PHYS maps

[Greg Kroah-Hartman]

On Tue, Jul 30, 2013 at 09:52:39AM +0200, Uwe Kleine-Konig wrote:
> [expanding Cc: to also include akpm and linux-mm]
> 
> Hello,
> 
> On Mon, Jul 29, 2013 at 01:09:14PM -0700, Greg Kroah-Hartman wrote:
> > On Sun, Jul 28, 2013 at 12:09:37AM +0200, Uwe Kleine-Konig wrote:
> > > This makes it possible to let gdb access mappings of the process that is
> > > being debugged.
> > > 
> > > uio_mmap_logical was moved and uio_vm_ops renamed to group related code
> > > and differentiate to new stuff.
> > > 
> > > Signed-off-by: Uwe Kleine-Konig <u.kleine-koenig@pengutronix.de>
> > > ---
> > > Changes since v1:
> > >     - only use generic_access_phys ifdef CONFIG_HAVE_IOREMAP_PROT
> > >     - fix all users of renamed struct
> > 
> > I still get a build error with this patch:
> > 
> >   MODPOST 384 modules
> > ERROR: "generic_access_phys" [drivers/uio/uio.ko] undefined!
> > 
> > So something isn't quite right.
> Ah, you built as a module and generic_access_phys isn't exported. The
> other users of generic_access_phys (arch/x86/pci/i386.c and
> drivers/char/mem.c) can only be builtin.
> 
> So the IMHO best option is to add an EXPORT_SYMBOL(generic_access_phys)
> to mm/memory.c.

EXPORT_SYMBOL_GPL() perhaps?

And why all of a sudden does the uio driver need this change?  It is
working just fine right now without it, right?

thanks,

greg k-h

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

Re: [PATCH v2 1/2] uio: provide vm access to UIO_MEM_PHYS maps

[Uwe Kleine-König]

Hello Greg,

On Tue, Jul 30, 2013 at 06:49:50AM -0700, Greg Kroah-Hartman wrote:
> On Tue, Jul 30, 2013 at 09:52:39AM +0200, Uwe Kleine-Konig wrote:
> > [expanding Cc: to also include akpm and linux-mm]
> > 
> > Hello,
> > 
> > On Mon, Jul 29, 2013 at 01:09:14PM -0700, Greg Kroah-Hartman wrote:
> > > On Sun, Jul 28, 2013 at 12:09:37AM +0200, Uwe Kleine-Konig wrote:
> > > > This makes it possible to let gdb access mappings of the process that is
> > > > being debugged.
> > > > 
> > > > uio_mmap_logical was moved and uio_vm_ops renamed to group related code
> > > > and differentiate to new stuff.
> > > > 
> > > > Signed-off-by: Uwe Kleine-Konig <u.kleine-koenig@pengutronix.de>
> > > > ---
> > > > Changes since v1:
> > > >     - only use generic_access_phys ifdef CONFIG_HAVE_IOREMAP_PROT
> > > >     - fix all users of renamed struct
> > > 
> > > I still get a build error with this patch:
> > > 
> > >   MODPOST 384 modules
> > > ERROR: "generic_access_phys" [drivers/uio/uio.ko] undefined!
> > > 
> > > So something isn't quite right.
> > Ah, you built as a module and generic_access_phys isn't exported. The
> > other users of generic_access_phys (arch/x86/pci/i386.c and
> > drivers/char/mem.c) can only be builtin.
> > 
> > So the IMHO best option is to add an EXPORT_SYMBOL(generic_access_phys)
> > to mm/memory.c.
> 
> EXPORT_SYMBOL_GPL() perhaps?
Yeah, that would work just fine, too. Who takes care for mm/memory.c,
Andrew? Should I send a separate patch or is it ok to do it in the patch
making use of it and let it go in via Greg?
 
> And why all of a sudden does the uio driver need this change?  It is
> working just fine right now without it, right?
Yeah it works. But if you gdb your userspace driver, gdb cannot access
the mappings without my patch.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-Konig            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

Re: [PATCH v2 1/2] uio: provide vm access to UIO_MEM_PHYS maps

[Greg Kroah-Hartman]

On Tue, Jul 30, 2013 at 04:32:37PM +0200, Uwe Kleine-Konig wrote:
> Hello Greg,
> 
> On Tue, Jul 30, 2013 at 06:49:50AM -0700, Greg Kroah-Hartman wrote:
> > On Tue, Jul 30, 2013 at 09:52:39AM +0200, Uwe Kleine-Konig wrote:
> > > [expanding Cc: to also include akpm and linux-mm]
> > > 
> > > Hello,
> > > 
> > > On Mon, Jul 29, 2013 at 01:09:14PM -0700, Greg Kroah-Hartman wrote:
> > > > On Sun, Jul 28, 2013 at 12:09:37AM +0200, Uwe Kleine-Konig wrote:
> > > > > This makes it possible to let gdb access mappings of the process that is
> > > > > being debugged.
> > > > > 
> > > > > uio_mmap_logical was moved and uio_vm_ops renamed to group related code
> > > > > and differentiate to new stuff.
> > > > > 
> > > > > Signed-off-by: Uwe Kleine-Konig <u.kleine-koenig@pengutronix.de>
> > > > > ---
> > > > > Changes since v1:
> > > > >     - only use generic_access_phys ifdef CONFIG_HAVE_IOREMAP_PROT
> > > > >     - fix all users of renamed struct
> > > > 
> > > > I still get a build error with this patch:
> > > > 
> > > >   MODPOST 384 modules
> > > > ERROR: "generic_access_phys" [drivers/uio/uio.ko] undefined!
> > > > 
> > > > So something isn't quite right.
> > > Ah, you built as a module and generic_access_phys isn't exported. The
> > > other users of generic_access_phys (arch/x86/pci/i386.c and
> > > drivers/char/mem.c) can only be builtin.
> > > 
> > > So the IMHO best option is to add an EXPORT_SYMBOL(generic_access_phys)
> > > to mm/memory.c.
> > 
> > EXPORT_SYMBOL_GPL() perhaps?
> Yeah, that would work just fine, too. Who takes care for mm/memory.c,
> Andrew? Should I send a separate patch or is it ok to do it in the patch
> making use of it and let it go in via Greg?

I can take it, in a patch before this one, if I get the acks from Andrew
and anyone else who "owns" that file (use get_maintainer.pl to determine
the proper people please.)

> > And why all of a sudden does the uio driver need this change?  It is
> > working just fine right now without it, right?
> Yeah it works. But if you gdb your userspace driver, gdb cannot access
> the mappings without my patch.

Ah, but who needs to use a debugger... :)

thanks,

greg k-h

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>