[PATCH] powerpc/pasemi: Use of_root in pas_pci_init()

[Christophe Leroy]

Le 06/09/2022 à 03:03, Michael Ellerman a écrit :
> Currently in pas_pci_init() a reference to the root node is leaked due
> to a missing of_node_put(). Instead just use of_root directly.
> 
> Note that converting to of_find_compatible_node(NULL, ...) would
> not be entirely equivalent, because that would check the compatible
> property of the root node, whereas using of_root skips checking the root
> node and start the search at the first child of the root.
> 

That seems to simplify code. Should we do the same in all places below ?

$ git grep -n "of_find_node_by_path(\"/\");" arch/powerpc/
arch/powerpc/kernel/pci_32.c:139:       dn = of_find_node_by_path("/");
arch/powerpc/kernel/pci_32.c:214:       dn = of_find_node_by_path("/");
arch/powerpc/kernel/setup-common.c:212: root = of_find_node_by_path("/");
arch/powerpc/kernel/setup-common.c:793: np = of_find_node_by_path("/");
arch/powerpc/mm/numa.c:388:             root = of_find_node_by_path("/");
arch/powerpc/mm/numa.c:456:             root = of_find_node_by_path("/");
arch/powerpc/platforms/52xx/efika.c:77: root = of_find_node_by_path("/");
arch/powerpc/platforms/52xx/efika.c:148:        root = 
of_find_node_by_path("/");
arch/powerpc/platforms/85xx/xes_mpc85xx.c:119:  root = 
of_find_node_by_path("/");
arch/powerpc/platforms/cell/setup.c:67: root = of_find_node_by_path("/");
arch/powerpc/platforms/cell/setup.c:154:        struct device_node *root 
= of_find_node_by_path("/");
arch/powerpc/platforms/chrp/pci.c:191:  struct device_node *root = 
of_find_node_by_path("/");
arch/powerpc/platforms/chrp/pci.c:216:  struct device_node *root = 
of_find_node_by_path("/");
arch/powerpc/platforms/chrp/setup.c:105:        root = 
of_find_node_by_path("/");
arch/powerpc/platforms/chrp/setup.c:201:        root = 
of_find_node_by_path("/");
arch/powerpc/platforms/chrp/setup.c:268:        node = 
of_find_node_by_path("/");
arch/powerpc/platforms/chrp/setup.c:299:        struct device_node *root 
= of_find_node_by_path("/");
arch/powerpc/platforms/chrp/setup.c:378:        root = 
of_find_node_by_path("/");
arch/powerpc/platforms/maple/pci.c:601: root = of_find_node_by_path("/");
arch/powerpc/platforms/maple/setup.c:225:       root = 
of_find_node_by_path("/");
arch/powerpc/platforms/pasemi/pci.c:276:        root = 
of_find_node_by_path("/");
arch/powerpc/platforms/pasemi/setup.c:268:      root = 
of_find_node_by_path("/");
arch/powerpc/platforms/powermac/pci.c:910:      root = 
of_find_node_by_path("/");
arch/powerpc/platforms/powermac/setup.c:105:    np = 
of_find_node_by_path("/");
arch/powerpc/platforms/powernv/setup.c:255:     root = 
of_find_node_by_path("/");
arch/powerpc/platforms/ps3/os-area.c:676:       node = 
of_find_node_by_path("/");
arch/powerpc/platforms/ps3/os-area.c:774:       node = 
of_find_node_by_path("/");
arch/powerpc/platforms/pseries/hotplug-memory.c:166:    parent = 
of_find_node_by_path("/");
arch/powerpc/platforms/pseries/ibmebus.c:187:   root = 
of_find_node_by_path("/");
arch/powerpc/platforms/pseries/lparcfg.c:232:   root = 
of_find_node_by_path("/");
arch/powerpc/platforms/pseries/lparcfg.c:799:   rootdn = 
of_find_node_by_path("/");
arch/powerpc/platforms/pseries/setup.c:97:      root = 
of_find_node_by_path("/");
arch/powerpc/platforms/pseries/setup.c:486:     struct device_node *root 
= of_find_node_by_path("/");
arch/powerpc/sysdev/xive/spapr.c:714:   rootdn = of_find_node_by_path("/");

Christophe


> Reported-by: Liang He <windhl at 126.com>
> Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
> ---
>   arch/powerpc/platforms/pasemi/pci.c | 10 ++--------
>   1 file changed, 2 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/pasemi/pci.c b/arch/powerpc/platforms/pasemi/pci.c
> index 55f0160910bf..f27d31414737 100644
> --- a/arch/powerpc/platforms/pasemi/pci.c
> +++ b/arch/powerpc/platforms/pasemi/pci.c
> @@ -270,18 +270,12 @@ static int __init pas_add_bridge(struct device_node *dev)
>   
>   void __init pas_pci_init(void)
>   {
> -	struct device_node *np, *root;
> +	struct device_node *np;
>   	int res;
>   
> -	root = of_find_node_by_path("/");
> -	if (!root) {
> -		pr_crit("pas_pci_init: can't find root of device tree\n");
> -		return;
> -	}
> -
>   	pci_set_flags(PCI_SCAN_ALL_PCIE_DEVS);
>   
> -	np = of_find_compatible_node(root, NULL, "pasemi,rootbus");
> +	np = of_find_compatible_node(of_root, NULL, "pasemi,rootbus");
>   	if (np) {
>   		res = pas_add_bridge(np);
>   		of_node_put(np);