On Thu, Mar 23, 2017 at 3:07 PM, Rob Herring <robh@xxxxxxxxxx> wrote:
> On Thu, Mar 23, 2017 at 3:12 AM, Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx> wrote:
>> Currently we only free the allocated resource struct when error.
>> This would cause memory leak after pci_free_resource_list.
>>
>> Signed-off-by: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
>> ---
>>
>> Changes in v2:
>> Don't change the resource_list_create_entry's behavior.
>>
>> drivers/of/of_pci.c | 57 +++++++++++++++++++++++------------------------------
>> 1 file changed, 25 insertions(+), 32 deletions(-)
>>
>> diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
>> index 0ee42c3..a0ec246 100644
>> --- a/drivers/of/of_pci.c
>> +++ b/drivers/of/of_pci.c
>> @@ -190,8 +190,7 @@ int of_pci_get_host_bridge_resources(struct device_node *dev,
>> struct list_head *resources, resource_size_t *io_base)
>> {
>> struct resource_entry *window;
>> - struct resource *res;
>> - struct resource *bus_range;
>> + struct resource res;
>> struct of_pci_range range;
>> struct of_pci_range_parser parser;
>> char range_type[4];
>> @@ -200,24 +199,24 @@ int of_pci_get_host_bridge_resources(struct device_node *dev,
>> if (io_base)
>> *io_base = (resource_size_t)OF_BAD_ADDR;
>>
>> - bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL);
>> - if (!bus_range)
>> - return -ENOMEM;
>> -
>> pr_info("host bridge %s ranges:\n", dev->full_name);
>>
>> - err = of_pci_parse_bus_range(dev, bus_range);
>> + err = of_pci_parse_bus_range(dev, &res);
>> if (err) {
>> - bus_range->start = busno;
>> - bus_range->end = bus_max;
>> - bus_range->flags = IORESOURCE_BUS;
>> - pr_info(" No bus range found for %s, using %pR\n",
>> - dev->full_name, bus_range);
>> + res.start = busno;
>> + res.end = bus_max;
>> + res.flags = IORESOURCE_BUS;
>> + pr_info(" No bus range found for %s\n", dev->full_name);
>> } else {
>> - if (bus_range->end > bus_range->start + bus_max)
>> - bus_range->end = bus_range->start + bus_max;
>> + if (res.end > res.start + bus_max)
>> + res.end = res.start + bus_max;
>> + }
>> + window = pci_add_resource(resources, NULL);
>> + if (!window) {
>> + err = -ENOMEM;
>> + goto parse_failed;
>> }
>> - pci_add_resource(resources, bus_range);
>> + *window->res = res;
>
> Well, now this seems racy. You add a blank resource to the list first
> and then fill it in.
>
Huh? There is absolutely no guarantees for concurrent access here.
pcI_add_resource_offset() first adds a resource and then modifies
offset. Here we add an empty resource and then fill it in.
Thanks.
--
Dmitry
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