Re: [PATCH] hw: Fix permissions for OCRDMA_RESET_STATS

[Selvin Xavier]

On Wed, Aug 16, 2017 at 12:01 AM, Leon Romanovsky <leon@xxxxxxxxxx> wrote:
> On Tue, Aug 08, 2017 at 06:56:37PM +0300, Anton Vasilyev wrote:
>> Debugfs file reset_stats is created with S_IRUSR permissions,
>> but ocrdma_dbgfs_ops_read() doesn't support OCRDMA_RESET_STATS,
>> whereas ocrdma_dbgfs_ops_write() supports only OCRDMA_RESET_STATS.
>>
>> The patch fixes misstype with permissions.
>>
>> Found by Linux Driver Verification project (linuxtesting.org).
>>
>> Signed-off-by: Anton Vasilyev <vasilyev@xxxxxxxxx>
>> ---
>>  drivers/infiniband/hw/ocrdma/ocrdma_stats.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/infiniband/hw/ocrdma/ocrdma_stats.c b/drivers/infiniband/hw/ocrdma/ocrdma_stats.c
>> index 66056f9..d42c617 100644
>> --- a/drivers/infiniband/hw/ocrdma/ocrdma_stats.c
>> +++ b/drivers/infiniband/hw/ocrdma/ocrdma_stats.c
>> @@ -834,7 +834,7 @@ void ocrdma_add_port_stats(struct ocrdma_dev *dev)
>>
>>       dev->reset_stats.type = OCRDMA_RESET_STATS;
>>       dev->reset_stats.dev = dev;
>> -     if (!debugfs_create_file("reset_stats", S_IRUSR, dev->dir,
>> +     if (!debugfs_create_file("reset_stats", S_IWUSR, dev->dir,
>>                               &dev->reset_stats, &ocrdma_dbg_ops))
>>               goto err;
>>
>
> If I didn't miss anything, the reset_stats knob wouldn't work.
>
> Any read of statistics from that debugfs will trigger the call to
> ocrdma_update_stats and it will call to ocrdma_mbx_rdma_stats(dev, false).
>
> For write operations to that "reset_stats", there is call
> to ocrdma_mbx_rdma_stats with second argument (reset) as true.
>
> But it doesn't do much with that "reset" argument, except update of reset_stats.
>
> git grep reset_stats drivers/infiniband/hw/ocrdma/* drivers/net/ethernet/emulex/
> drivers/infiniband/hw/ocrdma/ocrdma.h:  struct ocrdma_stats reset_stats;
> drivers/infiniband/hw/ocrdma/ocrdma_hw.c:               req->reset_stats = reset;

"reset" filed is passed down to the FW mailbox command to reset the
stats maintained by FW.
req is a pointer to dev->stats_mem.va and this is used to send down
the command to FW.
status = ocrdma_nonemb_mbx_cmd(dev, mqe, dev->stats_mem.va);


> drivers/infiniband/hw/ocrdma/ocrdma_sli.h:      u8 reset_stats;
> drivers/infiniband/hw/ocrdma/ocrdma_stats.c:    dev->reset_stats.type = OCRDMA_RESET_STATS;
> drivers/infiniband/hw/ocrdma/ocrdma_stats.c:    dev->reset_stats.dev = dev;
> drivers/infiniband/hw/ocrdma/ocrdma_stats.c:    if (!debugfs_create_file("reset_stats", S_IRUSR, dev->dir,
> drivers/infiniband/hw/ocrdma/ocrdma_stats.c:                            &dev->reset_stats, &ocrdma_dbg_ops))
> drivers/net/ethernet/emulex/benet/be_cmds.c:    req->cmd_params.params.reset_stats = 0;
> drivers/net/ethernet/emulex/benet/be_cmds.h:    u8 reset_stats;
>
> Thanks

The patch looks good to me.
Acked-by: Selvin Xavier <selvin.xavier@xxxxxxxxxxxx>

Thanks
Selvin