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[PATCH 2/2] of/pci: Fix memory leak in of_pci_get_host_bridge_resources
jeffy.chen at rock-chips
Mar 21, 2017, 8:20 PM
Post #1 of 4 (16 views)
Permalink
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@rock-chips.com>
---

drivers/of/of_pci.c | 48 +++++++++++++++---------------------------------
1 file changed, 15 insertions(+), 33 deletions(-)

diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
index 0ee42c3..269393bc 100644
--- a/drivers/of/of_pci.c
+++ b/drivers/of/of_pci.c
@@ -189,9 +189,7 @@ int of_pci_get_host_bridge_resources(struct device_node *dev,
unsigned char busno, unsigned char bus_max,
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 +198,19 @@ 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;
}
- pci_add_resource(resources, bus_range);
+ pci_add_resource(resources, &res);

/* Check for ranges property */
err = of_pci_range_parser_init(&parser, dev);
@@ -244,24 +237,16 @@ int of_pci_get_host_bridge_resources(struct device_node *dev,
if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
continue;

- res = kzalloc(sizeof(struct resource), GFP_KERNEL);
- if (!res) {
- err = -ENOMEM;
- goto parse_failed;
- }
-
- err = of_pci_range_to_resource(&range, dev, res);
- if (err) {
- kfree(res);
+ err = of_pci_range_to_resource(&range, dev, &res);
+ if (err)
continue;
- }

- if (resource_type(res) == IORESOURCE_IO) {
+ if (resource_type(&res) == IORESOURCE_IO) {
if (!io_base) {
pr_err("I/O range found for %s. Please provide an io_base pointer to save CPU base address\n",
dev->full_name);
err = -EINVAL;
- goto conversion_failed;
+ goto parse_failed;
}
if (*io_base != (resource_size_t)OF_BAD_ADDR)
pr_warn("More than one I/O resource converted for %s. CPU base address for old range lost!\n",
@@ -269,16 +254,13 @@ int of_pci_get_host_bridge_resources(struct device_node *dev,
*io_base = range.cpu_addr;
}

- pci_add_resource_offset(resources, res, res->start - range.pci_addr);
+ pci_add_resource_offset(resources, &res,
+ res.start - range.pci_addr);
}

return 0;

-conversion_failed:
- kfree(res);
parse_failed:
- resource_list_for_each_entry(window, resources)
- kfree(window->res);
pci_free_resource_list(resources);
return err;
}
--
2.1.4
Re: [PATCH 2/2] of/pci: Fix memory leak in of_pci_get_host_bridge_resources [ In reply to ]
robh at kernel
Mar 22, 2017, 8:20 AM
Post #2 of 4 (13 views)
Permalink
On Tue, Mar 21, 2017 at 9:25 PM, Jeffy Chen <jeffy.chen@rock-chips.com> 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@rock-chips.com>
> ---
>
> drivers/of/of_pci.c | 48 +++++++++++++++---------------------------------
> 1 file changed, 15 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
> index 0ee42c3..269393bc 100644
> --- a/drivers/of/of_pci.c
> +++ b/drivers/of/of_pci.c
> @@ -189,9 +189,7 @@ int of_pci_get_host_bridge_resources(struct device_node *dev,
> unsigned char busno, unsigned char bus_max,
> 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 +198,19 @@ 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;
> }
> - pci_add_resource(resources, bus_range);
> + pci_add_resource(resources, &res);

You are passing a stack variable to pci_add_resource and it doesn't
make a copy of it. I assume the resource needs to live after you exit
this function.

If we have a leak, can't you just add a free in the correct spot? That
would be a lot easier to review.

Rob
Re: [PATCH 2/2] of/pci: Fix memory leak in of_pci_get_host_bridge_resources [ In reply to ]
robh at kernel
Mar 22, 2017, 8:20 AM
Post #3 of 4 (13 views)
Permalink
On Wed, Mar 22, 2017 at 9:39 AM, Rob Herring <robh@kernel.org> wrote:
> On Tue, Mar 21, 2017 at 9:25 PM, Jeffy Chen <jeffy.chen@rock-chips.com> 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@rock-chips.com>
>> ---
>>
>> drivers/of/of_pci.c | 48 +++++++++++++++---------------------------------
>> 1 file changed, 15 insertions(+), 33 deletions(-)
>>
>> diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
>> index 0ee42c3..269393bc 100644
>> --- a/drivers/of/of_pci.c
>> +++ b/drivers/of/of_pci.c
>> @@ -189,9 +189,7 @@ int of_pci_get_host_bridge_resources(struct device_node *dev,
>> unsigned char busno, unsigned char bus_max,
>> 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 +198,19 @@ 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;
>> }
>> - pci_add_resource(resources, bus_range);
>> + pci_add_resource(resources, &res);
>
> You are passing a stack variable to pci_add_resource and it doesn't
> make a copy of it. I assume the resource needs to live after you exit
> this function.

Ah, found your 1st patch changing the behavior. I'm surprised that
change works without affecting anyone else.

> If we have a leak, can't you just add a free in the correct spot? That
> would be a lot easier to review.
>
> Rob
Re: [PATCH 2/2] of/pci: Fix memory leak in of_pci_get_host_bridge_resources [ In reply to ]
jeffy.chen at rock-chips
Mar 23, 2017, 2:20 AM
Post #4 of 4 (13 views)
Permalink
Hi Rob,

On 03/22/2017 10:55 PM, Rob Herring wrote:
> On Wed, Mar 22, 2017 at 9:39 AM, Rob Herring <robh@kernel.org> wrote:
>> On Tue, Mar 21, 2017 at 9:25 PM, Jeffy Chen <jeffy.chen@rock-chips.com> 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@rock-chips.com>
>>> ---
>>>
>>> drivers/of/of_pci.c | 48 +++++++++++++++---------------------------------
>>> 1 file changed, 15 insertions(+), 33 deletions(-)
>>>
>>> diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
>>> index 0ee42c3..269393bc 100644
>>> --- a/drivers/of/of_pci.c
>>> +++ b/drivers/of/of_pci.c
>>> @@ -189,9 +189,7 @@ int of_pci_get_host_bridge_resources(struct device_node *dev,
>>> unsigned char busno, unsigned char bus_max,
>>> 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 +198,19 @@ 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;
>>> }
>>> - pci_add_resource(resources, bus_range);
>>> + pci_add_resource(resources, &res);
>>
>> You are passing a stack variable to pci_add_resource and it doesn't
>> make a copy of it. I assume the resource needs to live after you exit
>> this function.
>
> Ah, found your 1st patch changing the behavior. I'm surprised that
> change works without affecting anyone else.
sorry, i should add a cover-letter first. and you're right, that would
affect others(for example the ioport_resource/iomem_resource).
>
>> If we have a leak, can't you just add a free in the correct spot? That
>> would be a lot easier to review.
it seems hard to tell which resources in the list need to be freed after
all...
>>
>> Rob
>
>
>

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