lkml.org 
[lkml]   [2013]   [Oct]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [tpmdd-devel] [PATCH 02/13] tpm atmel: Call request_region with the correct base
From
Date
On Wed, 2013-10-02 at 00:00 +0200, Peter Hüwe wrote:
> Am Montag, 23. September 2013, 20:14:32 schrieb Jason Gunthorpe:
>
> > Commit e0dd03caf20d040a0a86b6bd74028ec9bda545f5
>
> > changed the code path here so that ateml_get_base_addr
>
> > no longer directly altered the tpm_vendor_specific
>
> > structure, and instead placed the base address on the stack.
>
> >
>
> > The commit missed updating the request_region call, which
>
> > would have resulted in request_region being called with 0
>
> > as the base address.
>
Good catch!!

> >
>
> > I don't know if request_region(0, ..) will fail, if so the
>
> > driver has been broken since 2006 and we should remove it
>
> > from the tree as it has no users.
>
>
>
> The Atmel TPM depends on PPC64 || HAS_IOPORT
>
>
>
> So request_region is defined as
>
> #define request_region(start,n,name)
> __request_region(&ioport_resource, (start), (n), (name), 0)
>
> http://lxr.free-electrons.com/source/include/linux/ioport.h?a=powerpc#L174
>
>
>
> with the final check in
>
> __request_resource(struct resource *root, struct resource *new)
>
> ...
>
> 204 if (end < start)
>
> 205 return root;
>
> 206 if (start < root->start)
>
> 207 return root;
>
> 208 if (end > root->end)
>
> 209 return root;
>
>
>
>
>
> with root being ioport_resource, ioport_resource->start = 0 and
> new->start being 0
>
> so at least the basic check should work.
>
>
>
> Nevertheless it most probably does request and reserve the wrong
> region and if anything else has or wants to request the region it
> might cause a problem.
>
Would be interesting to see what problem this may cause. Unfortunately I
don't have a machine to test this.

>
>
> Does anyone (Ashley? IBM Fellows? Ted?) have access to one of those
> ancient tpms and maybe a machine to use test them?
>
See above. I will keep looking and will let you know if I can find one.

>
>
>
>
>
>
> I somewhat have the feeling that we should maybe begin to deprecate
> the vendor specific 1.1 tpms...
>
I agree. If we have a machine to test and it fails then we know we don't
have a user for this.

>
>
>
>
>
>
> Reviewed-by: Peter Huewe <peterhuewe@gmx.de>
>
> Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
>
>
>
> Staged here
> https://github.com/PeterHuewe/linux-tpmdd for-james
>
>
>
>
> Peter
>
>
>
> ------------------------------------------------------------------------------
> October Webinars: Code for Performance
> Free Intel webinars can help you accelerate application performance.
> Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from
> the latest Intel processors and coprocessors. See abstracts and register >
> http://pubads.g.doubleclick.net/gampad/clk?id=60134791&iu=/4140/ostg.clktrk
> _______________________________________________ tpmdd-devel mailing list tpmdd-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/tpmdd-devel


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2013-10-03 02:41    [W:0.193 / U:0.716 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site