Re: [PATCH v2 1/3] dma/idxd: fix memory leak in pci close

[Kevin Laatz <kevin.laatz@intel.com>]

On 04/07/2022 14:19, Bruce Richardson wrote:
> On Sun, Jul 03, 2022 at 01:22:41PM +0100, Kevin Laatz wrote:
>> ASAN reports a memory leak for the 'pci' pointer in the 'idxd_dmadev'
>> struct.
>>
>> This is fixed by free'ing the struct when the last queue on the PCI
>> device is being closed.
>>
>> Fixes: 9449330a8458 ("dma/idxd: create dmadev instances on PCI probe")
>> Cc: stable@dpdk.org
>> Cc: bruce.richardson@intel.com
>>
>> Reported-by: Xingguang He <xingguang.he@intel.com>
>> Signed-off-by: Kevin Laatz <kevin.laatz@intel.com>
>> ---
>>   drivers/dma/idxd/idxd_common.c   |  2 ++
>>   drivers/dma/idxd/idxd_internal.h |  2 ++
>>   drivers/dma/idxd/idxd_pci.c      | 34 +++++++++++++++++++++++++-------
>>   3 files changed, 31 insertions(+), 7 deletions(-)
>>
> Some comments inline below.
>
> /Bruce
>
>> diff --git a/drivers/dma/idxd/idxd_common.c b/drivers/dma/idxd/idxd_common.c
>> index c77200a457..d347bbed21 100644
>> --- a/drivers/dma/idxd/idxd_common.c
>> +++ b/drivers/dma/idxd/idxd_common.c
>> @@ -620,6 +620,8 @@ idxd_dmadev_create(const char *name, struct rte_device *dev,
>>   	dmadev->fp_obj->dev_private = idxd;
>>   
>>   	idxd->dmadev->state = RTE_DMA_DEV_READY;
>> +	if (idxd->u.pci != NULL)
>> +		rte_atomic16_inc(&idxd->u.pci->ref_count);
>>   
>>   	return 0;
>>   
> I don't think this belongs in the common code. Can it be put somewhere in
> the pci-specific driver code to avoid issues, e.g. after idxd_dmadev_create
> returns in probe_pci() function.

Sure, I'll look to move it in v3.

[snip]
>   
> @@ -159,12 +178,13 @@ init_pci_device(struct rte_pci_device *dev, struct idxd_dmadev *idxd,
>   	uint8_t lg2_max_batch, lg2_max_copy_size;
>   	unsigned int i, err_code;
>   
> -	pci = malloc(sizeof(*pci));
> +	pci = rte_malloc(NULL, sizeof(*pci), 0);
> Any particular reason for the change from regular malloc to rte_malloc?

Mainly consistency, its the only place in the driver where malloc is 
used instead of rte_malloc.

I have no strong preference here - I can remove the change for v3.

/Kevin