在 2021/5/24 上午10:06, Xuan Zhuo 写道:
On Mon, 24 May 2021 01:48:53 +0000, Guodeqing (A) <[email protected]>
wrote:
-----Original Message-----
From: Max Gurtovoy [mailto:[email protected]]
Sent: Sunday, May 23, 2021 15:25
To: Guodeqing (A) <[email protected]>; [email protected]
Cc: [email protected]; [email protected]; [email protected];
[email protected]; [email protected]
Subject: Re: [PATCH] virtio-net: fix the kzalloc/kfree mismatch problem
On 5/22/2021 11:02 AM, guodeqing wrote:
If the virtio_net device does not suppurt the ctrl queue feature, the
vi->ctrl was not allocated, so there is no need to free it.
you don't need this check.
from kfree doc:
"If @objp is NULL, no operation is performed."
This is not a bug. I've set vi->ctrl to be NULL in case !vi->has_cvq.
yes, this is not a bug, the patch is just a optimization, because the
vi->ctrl maybe
be freed which was not allocated, this may give people a misunderstanding.
Thanks.
I think it may be enough to add a comment, and the code does not need to be
modified.
Thanks.
Or even just leave the current code as is. A lot of kernel codes was
wrote under the assumption that kfree() should deal with NULL.
Thanks
Here I adjust the initialization sequence and the check of vi->has_cvq
to slove this problem.
Fixes: 122b84a1267a ("virtio-net: don't allocate control_buf if not
supported")
Signed-off-by: guodeqing <[email protected]>
---
drivers/net/virtio_net.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index
9b6a4a875c55..894f894d3a29 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2691,7 +2691,8 @@ static void virtnet_free_queues(struct
virtnet_info *vi)
kfree(vi->rq);
kfree(vi->sq);
- kfree(vi->ctrl);
+ if (vi->has_cvq)
+ kfree(vi->ctrl);
}
static void _free_receive_bufs(struct virtnet_info *vi) @@ -2870,13
+2871,6 @@ static int virtnet_alloc_queues(struct virtnet_info *vi)
{
int i;
- if (vi->has_cvq) {
- vi->ctrl = kzalloc(sizeof(*vi->ctrl), GFP_KERNEL);
- if (!vi->ctrl)
- goto err_ctrl;
- } else {
- vi->ctrl = NULL;
- }
vi->sq = kcalloc(vi->max_queue_pairs, sizeof(*vi->sq), GFP_KERNEL);
if (!vi->sq)
goto err_sq;
@@ -2884,6 +2878,12 @@ static int virtnet_alloc_queues(struct
virtnet_info *vi)
if (!vi->rq)
goto err_rq;
+ if (vi->has_cvq) {
+ vi->ctrl = kzalloc(sizeof(*vi->ctrl), GFP_KERNEL);
+ if (!vi->ctrl)
+ goto err_ctrl;
+ }
+
INIT_DELAYED_WORK(&vi->refill, refill_work);
for (i = 0; i < vi->max_queue_pairs; i++) {
vi->rq[i].pages = NULL;
@@ -2902,11 +2902,11 @@ static int virtnet_alloc_queues(struct
virtnet_info *vi)
return 0;
+err_ctrl:
+ kfree(vi->rq);
err_rq:
kfree(vi->sq);
err_sq:
- kfree(vi->ctrl);
-err_ctrl:
return -ENOMEM;
}
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