2022-07-01 10:05:24

by Yang Yingliang

[permalink] [raw]
Subject: [PATCH] bus: hisi_lpc: fix missing platform_device_put() in hisi_lpc_acpi_probe()

In error case in hisi_lpc_acpi_probe() after calling platform_device_add(),
hisi_lpc_acpi_remove() can't release the failed 'pdev', so it will be leak,
call platform_device_put() to fix this problem.
I'v constructed this error case and tested this patch on D05 board.

Fixes: 99c0228d6ff1 ("HISI LPC: Re-Add ACPI child enumeration support")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Yang Yingliang <[email protected]>
---
drivers/bus/hisi_lpc.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/bus/hisi_lpc.c b/drivers/bus/hisi_lpc.c
index 378f5d62a991..e7eaa8784fee 100644
--- a/drivers/bus/hisi_lpc.c
+++ b/drivers/bus/hisi_lpc.c
@@ -503,13 +503,13 @@ static int hisi_lpc_acpi_probe(struct device *hostdev)
{
struct acpi_device *adev = ACPI_COMPANION(hostdev);
struct acpi_device *child;
+ struct platform_device *pdev;
int ret;

/* Only consider the children of the host */
list_for_each_entry(child, &adev->children, node) {
const char *hid = acpi_device_hid(child);
const struct hisi_lpc_acpi_cell *cell;
- struct platform_device *pdev;
const struct resource *res;
bool found = false;
int num_res;
@@ -571,22 +571,24 @@ static int hisi_lpc_acpi_probe(struct device *hostdev)

ret = platform_device_add_resources(pdev, res, num_res);
if (ret)
- goto fail;
+ goto fail_put_device;

ret = platform_device_add_data(pdev, cell->pdata,
cell->pdata_size);
if (ret)
- goto fail;
+ goto fail_put_device;

ret = platform_device_add(pdev);
if (ret)
- goto fail;
+ goto fail_put_device;

acpi_device_set_enumerated(child);
}

return 0;

+fail_put_device:
+ platform_device_put(pdev);
fail:
hisi_lpc_acpi_remove(hostdev);
return ret;
--
2.25.1


2022-07-04 08:09:23

by John Garry

[permalink] [raw]
Subject: Re: [PATCH] bus: hisi_lpc: fix missing platform_device_put() in hisi_lpc_acpi_probe()

On 01/07/2022 10:43, Yang Yingliang wrote:

+

Please send any updated version cc'ing Rafael, who kindly offered to
pick up this patch

> In error case in hisi_lpc_acpi_probe() after calling platform_device_add(),
> hisi_lpc_acpi_remove() can't release the failed 'pdev', so it will be leak,
> call platform_device_put() to fix this problem.
> I'v constructed this error case and tested this patch on D05 board.
>
> Fixes: 99c0228d6ff1 ("HISI LPC: Re-Add ACPI child enumeration support")
> Reported-by: Hulk Robot <[email protected]>
> Signed-off-by: Yang Yingliang <[email protected]>
> ---
> drivers/bus/hisi_lpc.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/bus/hisi_lpc.c b/drivers/bus/hisi_lpc.c
> index 378f5d62a991..e7eaa8784fee 100644
> --- a/drivers/bus/hisi_lpc.c
> +++ b/drivers/bus/hisi_lpc.c
> @@ -503,13 +503,13 @@ static int hisi_lpc_acpi_probe(struct device *hostdev)
> {
> struct acpi_device *adev = ACPI_COMPANION(hostdev);
> struct acpi_device *child;
> + struct platform_device *pdev;

nit: please maintain reverse-firtree ordering

> int ret;
>
> /* Only consider the children of the host */
> list_for_each_entry(child, &adev->children, node) {
> const char *hid = acpi_device_hid(child);
> const struct hisi_lpc_acpi_cell *cell;
> - struct platform_device *pdev;
> const struct resource *res;
> bool found = false;
> int num_res;
> @@ -571,22 +571,24 @@ static int hisi_lpc_acpi_probe(struct device *hostdev)
>
> ret = platform_device_add_resources(pdev, res, num_res);
> if (ret)
> - goto fail;
> + goto fail_put_device;
>
> ret = platform_device_add_data(pdev, cell->pdata,
> cell->pdata_size);
> if (ret)
> - goto fail;
> + goto fail_put_device;
>
> ret = platform_device_add(pdev);
> if (ret)
> - goto fail;
> + goto fail_put_device;
>
> acpi_device_set_enumerated(child);
> }
>
> return 0;
>
> +fail_put_device:
> + platform_device_put(pdev);

is this enough? As I see, this invokes platform_device_release(), but we
would still need platform_device_del() to drop the pdev resources.
hisi_lpc_acpi_remove_subdev() calls platform_device_unregister(), so it
seems proper to do that here also. Please check it.

Thanks,
John

> fail:
> hisi_lpc_acpi_remove(hostdev);
> return ret;

2022-07-04 09:51:12

by Yang Yingliang

[permalink] [raw]
Subject: Re: [PATCH] bus: hisi_lpc: fix missing platform_device_put() in hisi_lpc_acpi_probe()


On 2022/7/4 16:01, John Garry wrote:
> On 01/07/2022 10:43, Yang Yingliang wrote:
>
> +
>
> Please send any updated version cc'ing Rafael, who kindly offered to
> pick up this patch
>
>>
[...]
>> @@ -503,13 +503,13 @@ static int hisi_lpc_acpi_probe(struct device
>> *hostdev)
>>   {
>>       struct acpi_device *adev = ACPI_COMPANION(hostdev);
>>       struct acpi_device *child;
>> +    struct platform_device *pdev;
>
> nit: please maintain reverse-firtree ordering
OK
>
>>       int ret;
>>         /* Only consider the children of the host */
>>       list_for_each_entry(child, &adev->children, node) {
>>           const char *hid = acpi_device_hid(child);
>>           const struct hisi_lpc_acpi_cell *cell;
>> -        struct platform_device *pdev;
>>           const struct resource *res;
>>           bool found = false;
>>           int num_res;
>> @@ -571,22 +571,24 @@ static int hisi_lpc_acpi_probe(struct device
>> *hostdev)
>>             ret = platform_device_add_resources(pdev, res, num_res);
>>           if (ret)
>> -            goto fail;
>> +            goto fail_put_device;
>>             ret = platform_device_add_data(pdev, cell->pdata,
>>                              cell->pdata_size);
>>           if (ret)
>> -            goto fail;
>> +            goto fail_put_device;
>>             ret = platform_device_add(pdev);
>>           if (ret)
>> -            goto fail;
>> +            goto fail_put_device;
>>             acpi_device_set_enumerated(child);
>>       }
>>         return 0;
>>   +fail_put_device:
>> +    platform_device_put(pdev);
>
> is this enough? As I see, this invokes platform_device_release(), but
> we would still need platform_device_del() to drop the pdev resources.
> hisi_lpc_acpi_remove_subdev() calls platform_device_unregister(), so
> it seems proper to do that here also. Please check it.
The resource allocated in platform_device_add_resources() is inserted by
platform_device_add(), if platform_device_add() is not called
successfully, freeing the resource in platform_device_release() is enough.
>
> Thanks,
> John
>
>>   fail:
>>       hisi_lpc_acpi_remove(hostdev);
>>       return ret;
>
> .