> Subject: Re: [PATCHv2 2/2] of: fix of_update_property()
>
> On Wed, 22 Jan 2014 13:57:40 +0800, Xiubo Li <Li.Xiubo@xxxxxxxxxxxxx> wrote:
> > The of_update_property() is intented to update a property in a node
> > and if the property does not exist, will add it.
> >
> > The second search of the property is possibly won't be found, that
> > maybe removed by other thread just before the second search begain.
> >
> > Using the __of_find_property() and __of_add_property() instead and
> > move them into lock operations.
> >
> > Signed-off-by: Xiubo Li <Li.Xiubo@xxxxxxxxxxxxx>
> > Cc: Pantelis Antoniou <panto@xxxxxxxxxxxxxxxxxxxxxxx>
>
> I've had to revert this patch. See below...
>
> > ---
> > drivers/of/base.c | 36 ++++++++++++++----------------------
> > 1 file changed, 14 insertions(+), 22 deletions(-)
> >
> > diff --git a/drivers/of/base.c b/drivers/of/base.c
> > index b86b77a..458072d 100644
> > --- a/drivers/of/base.c
> > +++ b/drivers/of/base.c
> > @@ -1573,7 +1573,7 @@ int of_update_property(struct device_node *np, struct
> property *newprop)
> > {
> > struct property **next, *oldprop;
> > unsigned long flags;
> > - int rc, found = 0;
> > + int rc = 0;
> >
> > rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
> > if (rc)
> > @@ -1582,36 +1582,28 @@ int of_update_property(struct device_node *np,
> struct property *newprop)
> > if (!newprop->name)
> > return -EINVAL;
> >
> > - oldprop = of_find_property(np, newprop->name, NULL);
> > - if (!oldprop)
> > - return of_add_property(np, newprop);
> > -
> > raw_spin_lock_irqsave(&devtree_lock, flags);
> > - next = &np->properties;
> > - while (*next) {
> > - if (*next == oldprop) {
> > - /* found the node */
> > - newprop->next = oldprop->next;
> > - *next = newprop;
> > - oldprop->next = np->deadprops;
> > - np->deadprops = oldprop;
> > - found = 1;
> > - break;
> > - }
> > - next = &(*next)->next;
> > + oldprop = __of_find_property(np, newprop->name, NULL);
> > + if (!oldprop) {
> > + /* add the node */
> > + rc = __of_add_property(np, newprop);
> > + } else {
> > + /* replace the node */
> > + next = &oldprop;
>
> Ugh. I just looked closer and the above line is completely broken.
> &oldprop is the address of 'oldprop' on the stack, *not* the address of
> the previous item in the list. The while loop is still required to find it.
>
Yes, I'll fix this.
Thanks very much.
BRs
Xiubo
> g.
>
> > + newprop->next = oldprop->next;
> > + *next = newprop;
> > + oldprop->next = np->deadprops;
> > + np->deadprops = oldprop;
> > }
> > raw_spin_unlock_irqrestore(&devtree_lock, flags);
> >
> > - if (!found)
> > - return -ENODEV;
> > -
> > #ifdef CONFIG_PROC_DEVICETREE
> > /* try to add to proc as well if it was initialized */
> > - if (np->pde)
> > + if (!rc && np->pde)
> > proc_device_tree_update_prop(np->pde, newprop, oldprop);
> > #endif /* CONFIG_PROC_DEVICETREE */
> >
> > - return 0;
> > + return rc;
> > }
> >
> > #if defined(CONFIG_OF_DYNAMIC)
> > --
> > 1.8.4
> >
> >
>
>
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