From: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
To: mst@redhat.com
Cc: jasowang@redhat.com, virtualization@lists.linux-foundation.org,
linux-kernel@vger.kernel.org, mopsfelder@gmail.com,
Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Subject: [PATCH] virtio-pci: Remove wrong address verification in vp_del_vqs()
Date: Thu, 14 Apr 2022 23:30:02 -0300 [thread overview]
Message-ID: <20220415023002.49805-1-muriloo@linux.ibm.com> (raw)
GCC 12 enhanced -Waddress when comparing array address to null [0],
which warns:
drivers/virtio/virtio_pci_common.c: In function ‘vp_del_vqs’:
drivers/virtio/virtio_pci_common.c:257:29: warning: the comparison will always evaluate as ‘true’ for the pointer operand in ‘vp_dev->msix_affinity_masks + (sizetype)((long unsigned int)i * 256)’ must not be NULL [-Waddress]
257 | if (vp_dev->msix_affinity_masks[i])
| ^~~~~~
In fact, the verification is comparing the result of a pointer
arithmetic, the address "msix_affinity_masks + i", which will always
evaluate to true.
Under the hood, free_cpumask_var() calls kfree(), which is safe to pass
NULL, not requiring non-null verification. So remove the verification
to make compiler happy (happy compiler, happy life).
[0] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102103
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
---
drivers/virtio/virtio_pci_common.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index d724f676608b..5046efcffb4c 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -254,8 +254,7 @@ void vp_del_vqs(struct virtio_device *vdev)
if (vp_dev->msix_affinity_masks) {
for (i = 0; i < vp_dev->msix_vectors; i++)
- if (vp_dev->msix_affinity_masks[i])
- free_cpumask_var(vp_dev->msix_affinity_masks[i]);
+ free_cpumask_var(vp_dev->msix_affinity_masks[i]);
}
if (vp_dev->msix_enabled) {
--
2.35.1
next reply other threads:[~2022-04-15 2:31 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-15 2:30 Murilo Opsfelder Araujo [this message]
2022-04-15 3:51 ` [PATCH] virtio-pci: Remove wrong address verification in vp_del_vqs() Murilo Opsfelder Araújo
2022-04-28 9:46 ` Christophe Marie Francois Dupont de Dinechin
2022-04-28 9:51 ` Christophe Marie Francois Dupont de Dinechin
2022-04-28 9:55 ` Christophe Marie Francois Dupont de Dinechin
2022-04-28 11:03 ` Michael S. Tsirkin
2022-04-28 11:52 ` Christophe Marie Francois Dupont de Dinechin
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