diff mbox series

[net,v2,3/3] net/ethtool/ioctl: split ethtool_get_phy_stats into multiple helpers

Message ID 20221226114825.1937189-4-d-tatianin@yandex-team.ru (mailing list archive)
State Accepted
Commit 201ed315f9676809cd5b20a39206e964106d4f27
Delegated to: Netdev Maintainers
Headers show
Series net/ethtool/ioctl: split ethtool_get_phy_stats into multiple helpers | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present fail Series targets non-next tree, but doesn't contain any Fixes tags
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/build_clang success Errors and warnings before: 1 this patch: 1
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/checkpatch fail CHECK: Alignment should match open parenthesis ERROR: open brace '{' following function definitions go on the next line WARNING: line length of 81 exceeds 80 columns WARNING: please, no spaces at the start of a line
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Daniil Tatianin Dec. 26, 2022, 11:48 a.m. UTC 
So that it's easier to follow and make sense of the branching and
various conditions.

Stats retrieval has been split into two separate functions
ethtool_get_phy_stats_phydev & ethtool_get_phy_stats_ethtool.
The former attempts to retrieve the stats using phydev & phy_ops, while
the latter uses ethtool_ops.

Actual n_stats validation & array allocation has been moved into a new
ethtool_vzalloc_stats_array helper.

This also fixes a potential NULL dereference of
ops->get_ethtool_phy_stats where it was getting called in an else branch
unconditionally without making sure it was actually present.

Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.

Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 net/ethtool/ioctl.c | 102 ++++++++++++++++++++++++++++++--------------
 1 file changed, 69 insertions(+), 33 deletions(-)
diff mbox series

Patch

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 3379af21c29f..36792633ce5f 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -2072,23 +2072,8 @@  static int ethtool_get_stats(struct net_device *dev, void __user *useraddr)
 	return ret;
 }
 
-static int ethtool_get_phy_stats(struct net_device *dev, void __user *useraddr)
+static int ethtool_vzalloc_stats_array(int n_stats, u64 **data)
 {
-	const struct ethtool_phy_ops *phy_ops = ethtool_phy_ops;
-	const struct ethtool_ops *ops = dev->ethtool_ops;
-	struct phy_device *phydev = dev->phydev;
-	struct ethtool_stats stats;
-	u64 *data;
-	int ret, n_stats;
-
-	if (!phydev && (!ops->get_ethtool_phy_stats || !ops->get_sset_count))
-		return -EOPNOTSUPP;
-
-	if (phydev && !ops->get_ethtool_phy_stats &&
-	    phy_ops && phy_ops->get_sset_count)
-		n_stats = phy_ops->get_sset_count(phydev);
-	else
-		n_stats = ops->get_sset_count(dev, ETH_SS_PHY_STATS);
 	if (n_stats < 0)
 		return n_stats;
 	if (n_stats > S32_MAX / sizeof(u64))
@@ -2096,31 +2081,82 @@  static int ethtool_get_phy_stats(struct net_device *dev, void __user *useraddr)
 	if (WARN_ON_ONCE(!n_stats))
 		return -EOPNOTSUPP;
 
+	*data = vzalloc(array_size(n_stats, sizeof(u64)));
+	if (!*data)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int ethtool_get_phy_stats_phydev(struct phy_device *phydev,
+					 struct ethtool_stats *stats,
+					 u64 **data)
+ {
+	const struct ethtool_phy_ops *phy_ops = ethtool_phy_ops;
+	int n_stats, ret;
+
+	if (!phy_ops || !phy_ops->get_sset_count || !phy_ops->get_stats)
+		return -EOPNOTSUPP;
+
+	n_stats = phy_ops->get_sset_count(phydev);
+
+	ret = ethtool_vzalloc_stats_array(n_stats, data);
+	if (ret)
+		return ret;
+
+	stats->n_stats = n_stats;
+	return phy_ops->get_stats(phydev, stats, *data);
+}
+
+static int ethtool_get_phy_stats_ethtool(struct net_device *dev,
+					  struct ethtool_stats *stats,
+					  u64 **data)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	int n_stats, ret;
+
+	if (!ops || !ops->get_sset_count || ops->get_ethtool_phy_stats)
+		return -EOPNOTSUPP;
+
+	n_stats = ops->get_sset_count(dev, ETH_SS_PHY_STATS);
+
+	ret = ethtool_vzalloc_stats_array(n_stats, data);
+	if (ret)
+		return ret;
+
+	stats->n_stats = n_stats;
+	ops->get_ethtool_phy_stats(dev, stats, *data);
+
+	return 0;
+}
+
+static int ethtool_get_phy_stats(struct net_device *dev, void __user *useraddr)
+{
+	struct phy_device *phydev = dev->phydev;
+	struct ethtool_stats stats;
+	u64 *data = NULL;
+	int ret = -EOPNOTSUPP;
+
 	if (copy_from_user(&stats, useraddr, sizeof(stats)))
 		return -EFAULT;
 
-	stats.n_stats = n_stats;
+	if (phydev)
+		ret = ethtool_get_phy_stats_phydev(phydev, &stats, &data);
 
-	data = vzalloc(array_size(n_stats, sizeof(u64)));
-	if (!data)
-		return -ENOMEM;
+	if (ret == -EOPNOTSUPP)
+		ret = ethtool_get_phy_stats_ethtool(dev, &stats, &data);
 
-	if (phydev && !ops->get_ethtool_phy_stats &&
-		phy_ops && phy_ops->get_stats) {
-		ret = phy_ops->get_stats(phydev, &stats, data);
-		if (ret < 0)
-			goto out;
-	} else {
-		ops->get_ethtool_phy_stats(dev, &stats, data);
-	}
+	if (ret)
+		goto out;
 
-	ret = -EFAULT;
-	if (copy_to_user(useraddr, &stats, sizeof(stats)))
+	if (copy_to_user(useraddr, &stats, sizeof(stats))) {
+		ret = -EFAULT;
 		goto out;
+	}
+
 	useraddr += sizeof(stats);
-	if (copy_to_user(useraddr, data, array_size(n_stats, sizeof(u64))))
-		goto out;
-	ret = 0;
+	if (copy_to_user(useraddr, data, array_size(stats.n_stats, sizeof(u64))))
+		ret = -EFAULT;
 
  out:
 	vfree(data);