RE: [PATCH 04/10] aacraid: Fix memory leak in aac_fib_map_free

[Raghava Aditya Renukunta <RaghavaAditya.Renukunta@pmcs.com>]

Hello Tomas,

> -----Original Message-----
> From: Tomas Henzl [mailto:thenzl@redhat.com]
> Sent: Monday, December 7, 2015 6:06 AM
> To: Raghava Aditya Renukunta; JBottomley@Parallels.com; linux-
> scsi@vger.kernel.org
> Cc: Mahesh Rajashekhara; Murthy Bhat; Santosh Akula; Gana Sridaran;
> aacraid@pmc-sierra.com; Rich Bono
> Subject: Re: [PATCH 04/10] aacraid: Fix memory leak in aac_fib_map_free
> 
> On 5.12.2015 01:40, Raghava Aditya Renukunta wrote:
> > Hello Tomas,
> >
> >
> >> -----Original Message-----
> >> From: Tomas Henzl [mailto:thenzl@redhat.com]
> >> Sent: Friday, December 4, 2015 6:35 AM
> >> To: Raghava Aditya Renukunta; JBottomley@Parallels.com; linux-
> >> scsi@vger.kernel.org
> >> Cc: Mahesh Rajashekhara; Murthy Bhat; Santosh Akula; Gana Sridaran;
> >> aacraid@pmc-sierra.com; Rich Bono
> >> Subject: Re: [PATCH 04/10] aacraid: Fix memory leak in aac_fib_map_free
> >>
> >> On 1.12.2015 13:39, Raghava Aditya Renukunta wrote:
> >>> From: Raghava Aditya Renukunta
> <raghavaaditya.renukunta@pmcs.com>
> >>>
> >>> aac_fib_map_free() calls pci_free_consistent() without checking that
> >>> dev->hw_fib_va is not NULL and dev->max_fib_size is not zero.If they
> >>> are indeed NULL/0, this will result in a hang as pci_free_consistent()
> >>> will attempt to invalidate cache for the entire 64-bit address space
> >>> (which would take a very long time).
> >>>
> >>> Fixed by adding a check to make sure that dev->hw_fib_va and
> >>> dev->max_fib_size are not NULL and 0 respectively.
> >>>
> >>> Signed-off-by: Raghava Aditya Renukunta
> >> <raghavaaditya.renukunta@pmcs.com>
> >>
> >> Reviewed-by: Tomas Henzl <thenzl@redhat.com>
> >>
> >> Is the can_queue constant during the driver's life, or is it possible
> >> to manipulate it (aac_change_queue_depth)?
> >>
> >> Tomas
> > can_queue is only changed in aac_init_adapter. Do you want to save
> >  (dev->scsi_host_ptr->can_queue + AAC_NUM_MGT_FIB) in a variable
> > So that the whole can_queue dereference need not be used?
> 
> It's fine as it is, (I thought it may change elsewhere in your code
> but now I think that I was wrong).
> 
> --tm

I will leave it as it is then.


> 
> >
> > Regards,
> > Raghava Aditya
> >
> >>> ---
> >>>  drivers/scsi/aacraid/commsup.c | 9 ++++++---
> >>>  1 file changed, 6 insertions(+), 3 deletions(-)
> >>>
> >>> diff --git a/drivers/scsi/aacraid/commsup.c
> >> b/drivers/scsi/aacraid/commsup.c
> >>> index b257d3b..9533f47 100644
> >>> --- a/drivers/scsi/aacraid/commsup.c
> >>> +++ b/drivers/scsi/aacraid/commsup.c
> >>> @@ -83,9 +83,12 @@ static int fib_map_alloc(struct aac_dev *dev)
> >>>
> >>>  void aac_fib_map_free(struct aac_dev *dev)
> >>>  {
> >>> -	pci_free_consistent(dev->pdev,
> >>> -	  dev->max_fib_size * (dev->scsi_host_ptr->can_queue +
> >> AAC_NUM_MGT_FIB),
> >>> -	  dev->hw_fib_va, dev->hw_fib_pa);
> >>> +	if (dev->hw_fib_va && dev->max_fib_size) {
> >>> +		pci_free_consistent(dev->pdev,
> >>> +		(dev->max_fib_size *
> >>> +		(dev->scsi_host_ptr->can_queue + AAC_NUM_MGT_FIB)),
> >>> +		dev->hw_fib_va, dev->hw_fib_pa);
> >>> +	}
> >>>  	dev->hw_fib_va = NULL;
> >>>  	dev->hw_fib_pa = 0;
> >>>  }
> > --
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