On Wed, Feb 03, 2021 at 05:36:01PM +0300, Dan Carpenter wrote:
On Wed, Feb 03, 2021 at 09:45:51PM +0800, Coiby Xu wrote:
Hi Dan,
On Wed, Feb 03, 2021 at 12:42:50PM +0300, Dan Carpenter wrote:
> Hello Coiby Xu,
>
> The patch 953b94009377: "staging: qlge: Initialize devlink health
> dump framework" from Jan 23, 2021, leads to the following static
> checker warning:
>
> drivers/staging/qlge/qlge_devlink.c:163 qlge_health_create_reporters()
> error: uninitialized symbol 'reporter'.
>
> drivers/staging/qlge/qlge_devlink.c
> 151 void qlge_health_create_reporters(struct qlge_adapter *priv)
> 152 {
> 153 struct devlink_health_reporter *reporter;
> 154 struct devlink *devlink;
> 155
> 156 devlink = priv_to_devlink(priv);
> 157 priv->reporter =
> 158 devlink_health_reporter_create(devlink,
&qlge_reporter_ops,
> 159 0, priv);
> 160 if (IS_ERR(priv->reporter))
> 161 netdev_warn(priv->ndev,
> 162 "Failed to create reporter, err = %ld\n",
> 163 PTR_ERR(reporter));
>
> Obviously the static checker is correct because we initialized
> "priv->reporter" instead of "reporter".
>
> It's not clear to me how "reporter" is used. Presumably this should be:
>
> reporter = devlink_health_reporter_create(devlink, &qlge_reporter_ops,
> 0, priv);
> if (IS_ERR(reporter)) {
> netdev_warn(priv->ndev,
> "Failed to create reporter, err = %ld\n",
> PTR_ERR(reporter));
> return;
> }
> priv->reporter = reporter;
>
Thank you for finding this issue! "struct devlink_health_reporter
*reporter" is not needed since priv->reporter is used instead which
I think simplifies the code.
> But I can't actually find where "priv->reporter" is checked against
> NULL. There should be some NULL checks, right?
>
There is no need to do NULL check since devlink_health_reporter_create
has done the job for us,
// net/core/devlink.c
__devlink_health_reporter_create(struct devlink *devlink,
const struct devlink_health_reporter_ops *ops,
u64 graceful_period, void *priv)
{
reporter = kzalloc(sizeof(*reporter), GFP_KERNEL);
if (!reporter)
return ERR_PTR(-ENOMEM);
}
No, Sorry I was unclear. I mean that instead of error handling this
qlge_health_create_reporters() function just prints an error:
netdev_warn(priv->ndev,
"Failed to create reporter, err = %ld\n",
PTR_ERR(priv->reporter));
Then it looks like it gets passed to qlge_reporter_coredump() which
dereferences "reporter" without checking. That will crash, right?
Now I see what you mean. Thanks for the explanation! I'll send a patch
to address this issue.
regards,
dan carpenter
--
Best regards,
Coiby
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