Re: [PATCH 1/2] state: don't keep pointers to any device tree data

[Michael Olbrich <m.olbrich@pengutronix.de>]

On Thu, Sep 15, 2016 at 10:13:36AM +0200, Sascha Hauer wrote:
> On Thu, Sep 15, 2016 at 08:10:13AM +0200, Michael Olbrich wrote:
> > Caching pointers to device tree nodes or names is not save. The barebox
> > internal device tree may be changed by loading a new device tree or through
> > fixup handlers.
> > Use local copies of the full path instead and resolve the node as needed.
> >
> 
> This should be two patches, one for backend->of_path and one
> state->root. When reviewing this I first had to understand that this
> patch has two unrelated changes.

Ok.

> > Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
> > ---
> >  common/state/backend.c |  3 ++-
> >  common/state/state.c   | 19 ++++++++++++-------
> >  common/state/state.h   |  4 ++--
> >  3 files changed, 16 insertions(+), 10 deletions(-)
> > 
> > diff --git a/common/state/backend.c b/common/state/backend.c
> > index 2f2e6dfd32d1..5235bb0283dd 100644
> > --- a/common/state/backend.c
> > +++ b/common/state/backend.c
> > @@ -164,7 +164,7 @@ int state_backend_init(struct state_backend *backend, struct device_d *dev,
> >  	if (ret)
> >  		goto out_free_format;
> >  
> > -	backend->of_path = of_path;
> > +	backend->of_path = xstrdup(of_path);
> >  
> >  	return 0;
> >  
> > @@ -185,4 +185,5 @@ void state_backend_free(struct state_backend *backend)
> >  	state_storage_free(&backend->storage);
> >  	if (backend->format)
> >  		state_format_free(backend->format);
> > +	free(backend->of_path);
> >  }
> > diff --git a/common/state/state.c b/common/state/state.c
> > index 9b1d4edef132..0c329cd67548 100644
> > --- a/common/state/state.c
> > +++ b/common/state/state.c
> > @@ -202,15 +202,19 @@ struct device_node *state_to_node(struct state *state,
> >  				  enum state_convert conv)
> >  {
> >  	struct device_node *child;
> > -	struct device_node *root;
> > +	struct device_node *root, *state_root;
> >  	int ret;
> >  
> > -	root = of_new_node(parent, state->root->name);
> > +	state_root = of_find_node_by_path(state->of_path);
> > +	if (!state_root)
> > +		return ERR_PTR(-ENODEV);
> 
> Shouldn't you create the node if it's not there in the target device
> tree?

This looks for the node in the barebox internal device tree, not the target
device tree. If this node is missing, then state does not work any more.

Michael

-- 
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