[PATCH 2/2] arch/powerpc/platforms/powermac/setup.c: add missing of_node_put
Julia Lawall
julia at diku.dk
Mon Aug 22 22:31:46 EST 2011
On Mon, 22 Aug 2011, walter harms wrote:
>
>
> Am 21.08.2011 18:10, schrieb Julia Lawall:
> > From: Julia Lawall <julia at diku.dk>
> >
> > np is initialized to the result of calling a function that calls
> > of_node_get, so of_node_put should be called before the pointer is dropped.
> >
> > The semantic match that finds this problem is as follows:
> > (http://coccinelle.lip6.fr/)
> >
> > // <smpl>
> > @@
> > expression e,e1,e2;
> > @@
> >
> > * e = \(of_find_node_by_type\|of_find_node_by_name\)(...)
> > ... when != of_node_put(e)
> > when != true e == NULL
> > when != e2 = e
> > e = e1
> > // </smpl>
> >
> > Signed-off-by: Julia Lawall <julia at diku.dk>
> >
> > ---
> > arch/powerpc/platforms/powermac/setup.c | 8 ++++++--
> > 1 file changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/powerpc/platforms/powermac/setup.c b/arch/powerpc/platforms/powermac/setup.c
> > index 96580b1..970ea1d 100644
> > --- a/arch/powerpc/platforms/powermac/setup.c
> > +++ b/arch/powerpc/platforms/powermac/setup.c
> > @@ -494,11 +494,15 @@ static int __init pmac_declare_of_platform_devices(void)
> > return -1;
> >
> > np = of_find_node_by_name(NULL, "valkyrie");
> > - if (np)
> > + if (np) {
> > of_platform_device_create(np, "valkyrie", NULL);
> > + of_node_put(np);
> > + }
> > np = of_find_node_by_name(NULL, "platinum");
> > - if (np)
> > + if (np) {
> > of_platform_device_create(np, "platinum", NULL);
> > + of_node_put(np);
> > + }
> > np = of_find_node_by_type(NULL, "smu");
> > if (np) {
> > of_platform_device_create(np, "smu", NULL);
> >
>
>
> hi,
> it seems save to call of_node_put(np) with np==NULL, i assume the same is true
> for of_platform_device_create().
>
> so the code collapses to:
>
> _test_node(char *name)
> {
> struct device_node *np;
> np = of_find_node_by_name(NULL, name);
> of_platform_device_create(np, name, NULL);
> of_node_put(np);
> return NULL?:0:1;
> }
>
> maybe there is already something like find_node() ?
of_platform_device_create is not much used, and one might want to use it
with other functions than of_find_node_by_name, as indeed is done here.
Is the problem just a missing else between the calls? Is it certain that
all of the cases are disjoint?
julia
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