Re: [PATCH 1/2] skd: fix msix error handling

[Jens Axboe]

On 11/09/2016 05:55 AM, Arnd Bergmann wrote:

As reported by gcc -Wmaybe-uninitialized, the cleanup path for
skd_acquire_msix tries to free the already allocated msi-x vectors
in reverse order, but the index variable may not have been
used yet:

drivers/block/skd_main.c: In function ‘skd_acquire_irq’:
drivers/block/skd_main.c:3890:8: error: ‘i’ may be used uninitialized in this 
function [-Werror=maybe-uninitialized]

This changes the failure path to skip releasing the interrupts
if we have not started requesting them yet.


Applied both patches, thanks Arnd.

--
Jens Axboe

Re: [PATCH 1/2] skd: fix msix error handling

[Christoph Hellwig]

Thanks Arnd,

this looks fine:

Reviewed-by: Christoph Hellwig 

[PATCH 1/2] skd: fix msix error handling

[Arnd Bergmann]

As reported by gcc -Wmaybe-uninitialized, the cleanup path for
skd_acquire_msix tries to free the already allocated msi-x vectors
in reverse order, but the index variable may not have been
used yet:

drivers/block/skd_main.c: In function ‘skd_acquire_irq’:
drivers/block/skd_main.c:3890:8: error: ‘i’ may be used uninitialized in this 
function [-Werror=maybe-uninitialized]

This changes the failure path to skip releasing the interrupts
if we have not started requesting them yet.

Fixes: 180b0ae77d49 ("skd: use pci_alloc_irq_vectors")
Signed-off-by: Arnd Bergmann 
---
 drivers/block/skd_main.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
index a58256cd94d7..66146b349229 100644
--- a/drivers/block/skd_main.c
+++ b/drivers/block/skd_main.c
@@ -3849,7 +3849,7 @@ static int skd_acquire_msix(struct skd_device *skdev)
if (rc < 0) {
pr_err("(%s): failed to enable MSI-X %d\n",
   skd_name(skdev), rc);
-   goto msix_out;
+   goto out;
}
 
skdev->msix_entries = kcalloc(SKD_MAX_MSIX_COUNT,
@@ -3858,7 +3858,7 @@ static int skd_acquire_msix(struct skd_device *skdev)
rc = -ENOMEM;
pr_err("(%s): msix table allocation error\n",
   skd_name(skdev));
-   goto msix_out;
+   goto out;
}
 
/* Enable MSI-X vectors for the base queue */
@@ -3889,6 +3889,7 @@ static int skd_acquire_msix(struct skd_device *skdev)
 msix_out:
while (--i >= 0)
devm_free_irq(&pdev->dev, pci_irq_vector(pdev, i), skdev);
+out:
kfree(skdev->msix_entries);
skdev->msix_entries = NULL;
return rc;
-- 
2.9.0