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Re: [PATCH v2] powerpc/mpc5xxx: Avoid dereferencing potentially freed memory

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On Fri, 2015-10-16 at 08:20 +0200, Christophe JAILLET wrote:
> Le 15/10/2015 08:36, Michael Ellerman a écrit :
> > On Thu, 2015-10-15 at 07:56 +0200, Christophe JAILLET wrote:
> > > Use 'of_property_read_u32()' instead of
> > > 'of_get_property()'+pointer
> > > dereference in order to avoid access to potentially freed memory.
> > > 
> > > Use 'of_get_next_parent()' to simplify the while() loop and avoid
> > > the
> > > need of a temp variable.
> > > 
> > > Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> > > ---
> > > v2: Use of_property_read_u32 instead of of_get_property+pointer
> > > dereference
> > > *** Untested ***
> > Thanks.
> > 
> > Can someone with an mpc5xxx test this?
> 
> Hi,
> I don't think it is an issue, but while looking at another similar 
> patch, I noticed that the proposed patch adds a call to
> be32_to_cpup() 
> (within of_property_read_u32).
> Apparently, powerPC is a BE architecture, so this call should be a no
> -op.
> 
> Just wanted to point it out, in case of.

Hi Christoph,

I'm not sure I follow.

The device tree is always big endian, but of_property_read_u32() does
the
conversion to CPU endian for you already. That is one of the advantages
of
using it.

cheers

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[PATCH] powerpc/mpc5xxx: Use of_get_next_parent to simplify code Christophe JAILLET <christophe.jaillet@wanadoo.fr> - 2015-10-11 22:40 +0200
  Re: [PATCH] powerpc/mpc5xxx: Use of_get_next_parent to simplify  code Julia Lawall <julia.lawall@lip6.fr> - 2015-10-11 22:50 +0200
    Re: [PATCH] powerpc/mpc5xxx: Use of_get_next_parent to simplify code Christophe JAILLET <christophe.jaillet@wanadoo.fr> - 2015-10-12 07:10 +0200
  Re: powerpc/mpc5xxx: Use of_get_next_parent to simplify code Michael Ellerman <mpe@ellerman.id.au> - 2015-10-14 06:10 +0200
    [PATCH v2] powerpc/mpc5xxx: Avoid dereferencing potentially freed memory Christophe JAILLET <christophe.jaillet@wanadoo.fr> - 2015-10-15 08:00 +0200
      Re: [PATCH v2] powerpc/mpc5xxx: Avoid dereferencing potentially  freed memory Michael Ellerman <mpe@ellerman.id.au> - 2015-10-15 08:40 +0200
        Re: [PATCH v2] powerpc/mpc5xxx: Avoid dereferencing potentially freed  memory Christophe JAILLET <christophe.jaillet@wanadoo.fr> - 2015-10-16 08:30 +0200
          Re: [PATCH v2] powerpc/mpc5xxx: Avoid dereferencing potentially  freed memory Gabriel Paubert <paubert@iram.es> - 2015-10-16 09:50 +0200
          Re: [PATCH v2] powerpc/mpc5xxx: Avoid dereferencing potentially  freed memory Michael Ellerman <mpe@ellerman.id.au> - 2015-10-16 11:50 +0200
            Re: [PATCH v2] powerpc/mpc5xxx: Avoid dereferencing potentially freed  memory Christophe JAILLET <christophe.jaillet@wanadoo.fr> - 2015-10-16 22:10 +0200
  Re: powerpc/mpc5xxx: Use of_get_next_parent to simplify code Michael Ellerman <mpe@ellerman.id.au> - 2015-10-15 13:20 +0200

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