Re: [PATCH] drivers/scsi/ipr.c: reorder error handling code toinclude iounmap

From: Julia Lawall
Date: Wed Jun 15 2011 - 04:51:12 EST


On Tue, 14 Jun 2011, Brian King wrote:

> On 06/09/2011 10:51 AM, Wayne Boyer wrote:
> > On 05/31/2011 07:16 AM, Julia Lawall wrote:
> >> From: Julia Lawall <julia@xxxxxxx>
> >>
> >> The out_msi_disable label should be before cleanup_nomem to additionally
> >> benefit from the call to iounmap.
> >
> > Yes, this is a problem. I propose the following patch instead.
>
> By removing the out_msi_disable label, if you fail initialization later
> on and goto cleanup_nomem, you will end up leaving MSI enabled when you exit
> with this patch.

I agree.

julia

> -Brian
>
>
>
> >
> > ---
> >
> > In the case where ipr_test_msi returns an error that is not -EOPNOTSUPP, the
> > execution jumps to the out_msi_disable label. This misses the call to iounmap
> > for ipr_regs which was initialized earlier.
> >
> > The fix is to do the call to pci_disable_msi when the error case is detected
> > and then goto the cleanup_nomem label if the error is not -EOPNOTSUPP.
> >
> > Signed-off-by: Wayne Boyer <wayneb@xxxxxxxxxxxxxxxxxx>
> > ---
> >
> > drivers/scsi/ipr.c | 10 ++++------
> > 1 file changed, 4 insertions(+), 6 deletions(-)
> >
> > Index: b/drivers/scsi/ipr.c
> > ===================================================================
> > --- a/drivers/scsi/ipr.c 2011-06-09 08:14:44.927740117 -0700
> > +++ b/drivers/scsi/ipr.c 2011-06-09 08:50:10.105630466 -0700
> > @@ -8763,11 +8763,11 @@ static int __devinit ipr_probe_ioa(struc
> > /* Enable MSI style interrupts if they are supported. */
> > if (ioa_cfg->ipr_chip->intr_type == IPR_USE_MSI && !pci_enable_msi(pdev)) {
> > rc = ipr_test_msi(ioa_cfg, pdev);
> > - if (rc == -EOPNOTSUPP)
> > + if (rc) {
> > pci_disable_msi(pdev);
> > - else if (rc)
> > - goto out_msi_disable;
> > - else
> > + if (rc != -EOPNOTSUPP)
> > + goto cleanup_nomem;
> > + } else
> > dev_info(&pdev->dev, "MSI enabled with IRQ: %d\n", pdev->irq);
> > } else if (ipr_debug)
> > dev_info(&pdev->dev, "Cannot enable MSI.\n");
> > @@ -8847,8 +8847,6 @@ cleanup_nolog:
> > ipr_free_mem(ioa_cfg);
> > cleanup_nomem:
> > iounmap(ipr_regs);
> > -out_msi_disable:
> > - pci_disable_msi(pdev);
> > out_release_regions:
> > pci_release_regions(pdev);
> > out_scsi_host_put:
> >
> >
>
>
> --
> Brian King
> Linux on Power Virtualization
> IBM Linux Technology Center
>
>
> --
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