[v4,3/3] eal: fix a wrong returned value when callback exists
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Commit Message
From: Yunjian Wang <wangyunjian@huawei.com>
We should return an error value, when the callback is already exist.
Fixes: a753e53d517b ("eal: add device event monitor framework")
Cc: stable@dpdk.org
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
---
lib/librte_eal/common/eal_common_dev.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
Comments
On Fri, Jul 3, 2020 at 11:47 AM wangyunjian <wangyunjian@huawei.com> wrote:
>
> From: Yunjian Wang <wangyunjian@huawei.com>
>
> We should return an error value, when the callback is already exist.
>
> Fixes: a753e53d517b ("eal: add device event monitor framework")
> Cc: stable@dpdk.org
>
> Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
> ---
> lib/librte_eal/common/eal_common_dev.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/lib/librte_eal/common/eal_common_dev.c b/lib/librte_eal/common/eal_common_dev.c
> index d990bfd..2a097aa 100644
> --- a/lib/librte_eal/common/eal_common_dev.c
> +++ b/lib/librte_eal/common/eal_common_dev.c
> @@ -431,7 +431,7 @@ static int cmp_dev_name(const struct rte_device *dev, const void *_name)
> void *cb_arg)
> {
> struct dev_event_callback *event_cb;
> - int ret;
> + int ret = 0;
>
> if (!cb_fn)
> return -EINVAL;
> @@ -484,7 +484,7 @@ static int cmp_dev_name(const struct rte_device *dev, const void *_name)
> }
>
> rte_spinlock_unlock(&dev_event_lock);
> - return 0;
> + return ret;
> error:
> free(event_cb);
> rte_spinlock_unlock(&dev_event_lock);
> --
> 1.8.3.1
A simpler fix is to directly jump to the error label.
This has the advantage of having all errors go through a single cleanup code:
diff --git a/lib/librte_eal/common/eal_common_dev.c
b/lib/librte_eal/common/eal_common_dev.c
index 9e4f09d83e..fa47074b0b 100644
--- a/lib/librte_eal/common/eal_common_dev.c
+++ b/lib/librte_eal/common/eal_common_dev.c
@@ -480,7 +480,9 @@ rte_dev_event_callback_register(const char *device_name,
RTE_LOG(ERR, EAL,
"The callback is already exist, no need "
"to register again.\n");
+ event_cb = NULL;
ret = -EEXIST;
+ goto error;
}
rte_spinlock_unlock(&dev_event_lock);
What do you think?
> -----Original Message-----
> From: David Marchand [mailto:david.marchand@redhat.com]
> Sent: Tuesday, October 20, 2020 9:19 PM
> To: wangyunjian <wangyunjian@huawei.com>; Jeff Guo <jia.guo@intel.com>
> Cc: dev <dev@dpdk.org>; Lilijun (Jerry) <jerry.lilijun@huawei.com>; xudingke
> <xudingke@huawei.com>; dpdk stable <stable@dpdk.org>
> Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH v4 3/3] eal: fix a wrong returned
> value when callback exists
>
> On Fri, Jul 3, 2020 at 11:47 AM wangyunjian <wangyunjian@huawei.com>
> wrote:
> >
> > From: Yunjian Wang <wangyunjian@huawei.com>
> >
> > We should return an error value, when the callback is already exist.
> >
> > Fixes: a753e53d517b ("eal: add device event monitor framework")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
> > ---
> > lib/librte_eal/common/eal_common_dev.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/lib/librte_eal/common/eal_common_dev.c
> > b/lib/librte_eal/common/eal_common_dev.c
> > index d990bfd..2a097aa 100644
> > --- a/lib/librte_eal/common/eal_common_dev.c
> > +++ b/lib/librte_eal/common/eal_common_dev.c
> > @@ -431,7 +431,7 @@ static int cmp_dev_name(const struct rte_device
> *dev, const void *_name)
> > void *cb_arg) {
> > struct dev_event_callback *event_cb;
> > - int ret;
> > + int ret = 0;
> >
> > if (!cb_fn)
> > return -EINVAL;
> > @@ -484,7 +484,7 @@ static int cmp_dev_name(const struct rte_device
> *dev, const void *_name)
> > }
> >
> > rte_spinlock_unlock(&dev_event_lock);
> > - return 0;
> > + return ret;
> > error:
> > free(event_cb);
> > rte_spinlock_unlock(&dev_event_lock);
> > --
> > 1.8.3.1
>
> A simpler fix is to directly jump to the error label.
> This has the advantage of having all errors go through a single cleanup code:
>
> diff --git a/lib/librte_eal/common/eal_common_dev.c
> b/lib/librte_eal/common/eal_common_dev.c
> index 9e4f09d83e..fa47074b0b 100644
> --- a/lib/librte_eal/common/eal_common_dev.c
> +++ b/lib/librte_eal/common/eal_common_dev.c
> @@ -480,7 +480,9 @@ rte_dev_event_callback_register(const char
> *device_name,
> RTE_LOG(ERR, EAL,
> "The callback is already exist, no need "
> "to register again.\n");
> + event_cb = NULL;
> ret = -EEXIST;
> + goto error;
> }
>
> rte_spinlock_unlock(&dev_event_lock);
>
> What do you think?
Agree, I will update it in next version.
Yunjian
>
>
> --
> David Marchand
@@ -431,7 +431,7 @@ static int cmp_dev_name(const struct rte_device *dev, const void *_name)
void *cb_arg)
{
struct dev_event_callback *event_cb;
- int ret;
+ int ret = 0;
if (!cb_fn)
return -EINVAL;
@@ -484,7 +484,7 @@ static int cmp_dev_name(const struct rte_device *dev, const void *_name)
}
rte_spinlock_unlock(&dev_event_lock);
- return 0;
+ return ret;
error:
free(event_cb);
rte_spinlock_unlock(&dev_event_lock);