Re: [PATCH] drivers/scsi/ipr.c: reorder error handling code to includeiounmap

From: Brian King
Date: Tue Jun 14 2011 - 12:10:01 EST


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.

-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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