Re: [PATCH] net: x25: Optimize the code in {compat_}x25_subscr_ioctl()

From: Martin Schiller
Date: Thu Jul 01 2021 - 01:58:15 EST


On 2021-06-30 11:15, Yajun Deng wrote:
Combine the redundant return values, make it more concise.

Signed-off-by: Yajun Deng <yajun.deng@xxxxxxxxx>
---
net/x25/af_x25.c | 19 ++++++++-----------
net/x25/x25_link.c | 21 ++++++++++-----------
2 files changed, 18 insertions(+), 22 deletions(-)

diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c
index 3583354a7d7f..53c40fc7c1fd 100644
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -1625,21 +1625,19 @@ static int compat_x25_subscr_ioctl(unsigned int cmd,
struct net_device *dev;
int rc = -EINVAL;

- rc = -EFAULT;
- if (copy_from_user(&x25_subscr, x25_subscr32, sizeof(*x25_subscr32)))
+ if (copy_from_user(&x25_subscr, x25_subscr32, sizeof(*x25_subscr32))) {
+ rc = -EFAULT;
goto out;
+ }

- rc = -EINVAL;
dev = x25_dev_get(x25_subscr.device);
- if (dev == NULL)
+ if (!dev)
goto out;

nb = x25_get_neigh(dev);
- if (nb == NULL)
+ if (!nb)
goto out_dev_put;

- dev_put(dev);
-
if (cmd == SIOCX25GSUBSCRIP) {
read_lock_bh(&x25_neigh_list_lock);
x25_subscr.extended = nb->extended;
@@ -1648,7 +1646,6 @@ static int compat_x25_subscr_ioctl(unsigned int cmd,
rc = copy_to_user(x25_subscr32, &x25_subscr,
sizeof(*x25_subscr32)) ? -EFAULT : 0;
} else {
- rc = -EINVAL;
if (x25_subscr.extended == 0 || x25_subscr.extended == 1) {
rc = 0;
write_lock_bh(&x25_neigh_list_lock);
@@ -1658,11 +1655,11 @@ static int compat_x25_subscr_ioctl(unsigned int cmd,
}
}
x25_neigh_put(nb);
-out:
- return rc;
+
out_dev_put:
dev_put(dev);
- goto out;
+out:
+ return rc;
}

static int compat_x25_ioctl(struct socket *sock, unsigned int cmd,
diff --git a/net/x25/x25_link.c b/net/x25/x25_link.c
index 5460b9146dd8..01a13ec88ce8 100644
--- a/net/x25/x25_link.c
+++ b/net/x25/x25_link.c
@@ -360,19 +360,19 @@ int x25_subscr_ioctl(unsigned int cmd, void __user *arg)
if (cmd != SIOCX25GSUBSCRIP && cmd != SIOCX25SSUBSCRIP)
goto out;

- rc = -EFAULT;
- if (copy_from_user(&x25_subscr, arg, sizeof(x25_subscr)))
+ if (copy_from_user(&x25_subscr, arg, sizeof(x25_subscr))) {
+ rc = -EFAULT;
goto out;
+ }

- rc = -EINVAL;
- if ((dev = x25_dev_get(x25_subscr.device)) == NULL)
+ dev = x25_dev_get(x25_subscr.device);
+ if (!dev)
goto out;

- if ((nb = x25_get_neigh(dev)) == NULL)
+ nb = x25_get_neigh(dev);
+ if (!nb)
goto out_dev_put;

- dev_put(dev);
-
if (cmd == SIOCX25GSUBSCRIP) {
read_lock_bh(&x25_neigh_list_lock);
x25_subscr.extended = nb->extended;
@@ -381,7 +381,6 @@ int x25_subscr_ioctl(unsigned int cmd, void __user *arg)
rc = copy_to_user(arg, &x25_subscr,
sizeof(x25_subscr)) ? -EFAULT : 0;
} else {
- rc = -EINVAL;
if (!(x25_subscr.extended && x25_subscr.extended != 1)) {
rc = 0;
write_lock_bh(&x25_neigh_list_lock);
@@ -391,11 +390,11 @@ int x25_subscr_ioctl(unsigned int cmd, void __user *arg)
}
}
x25_neigh_put(nb);
-out:
- return rc;
+
out_dev_put:
dev_put(dev);
- goto out;
+out:
+ return rc;
}

Looks good to me.

Acked-by: Martin Schiller <ms@xxxxxxxxxx>