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authorMenglong Dong <imagedong@tencent.com>2022-01-09 14:36:26 +0800
committerJakub Kicinski <kuba@kernel.org>2022-01-09 16:30:34 -0800
commitc504e5c2f9648a1e5c2be01e8c3f59d394192bd3 (patch)
tree7b0bfa659d35796ab251cccfc8ad6e9ed264df89 /net/core
parent342402c426902c59491b43d3056a1039e5ca02db (diff)
net: skb: introduce kfree_skb_reason()
Introduce the interface kfree_skb_reason(), which is able to pass the reason why the skb is dropped to 'kfree_skb' tracepoint. Add the 'reason' field to 'trace_kfree_skb', therefor user can get more detail information about abnormal skb with 'drop_monitor' or eBPF. All drop reasons are defined in the enum 'skb_drop_reason', and they will be print as string in 'kfree_skb' tracepoint in format of 'reason: XXX'. ( Maybe the reasons should be defined in a uapi header file, so that user space can use them? ) Signed-off-by: Menglong Dong <imagedong@tencent.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/dev.c3
-rw-r--r--net/core/drop_monitor.c10
-rw-r--r--net/core/skbuff.c12
3 files changed, 16 insertions, 9 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 83a4089990a0..84a0d9542fe9 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4899,7 +4899,8 @@ static __latent_entropy void net_tx_action(struct softirq_action *h)
if (likely(get_kfree_skb_cb(skb)->reason == SKB_REASON_CONSUMED))
trace_consume_skb(skb);
else
- trace_kfree_skb(skb, net_tx_action);
+ trace_kfree_skb(skb, net_tx_action,
+ SKB_DROP_REASON_NOT_SPECIFIED);
if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
__kfree_skb(skb);
diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c
index 3d0ab2eec916..7b288a121a41 100644
--- a/net/core/drop_monitor.c
+++ b/net/core/drop_monitor.c
@@ -110,7 +110,8 @@ static u32 net_dm_queue_len = 1000;
struct net_dm_alert_ops {
void (*kfree_skb_probe)(void *ignore, struct sk_buff *skb,
- void *location);
+ void *location,
+ enum skb_drop_reason reason);
void (*napi_poll_probe)(void *ignore, struct napi_struct *napi,
int work, int budget);
void (*work_item_func)(struct work_struct *work);
@@ -262,7 +263,9 @@ out:
spin_unlock_irqrestore(&data->lock, flags);
}
-static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb, void *location)
+static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb,
+ void *location,
+ enum skb_drop_reason reason)
{
trace_drop_common(skb, location);
}
@@ -490,7 +493,8 @@ static const struct net_dm_alert_ops net_dm_alert_summary_ops = {
static void net_dm_packet_trace_kfree_skb_hit(void *ignore,
struct sk_buff *skb,
- void *location)
+ void *location,
+ enum skb_drop_reason reason)
{
ktime_t tstamp = ktime_get_real();
struct per_cpu_dm_data *data;
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index e514a36bcffc..0118f0afaa4f 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -759,21 +759,23 @@ void __kfree_skb(struct sk_buff *skb)
EXPORT_SYMBOL(__kfree_skb);
/**
- * kfree_skb - free an sk_buff
+ * kfree_skb_reason - free an sk_buff with special reason
* @skb: buffer to free
+ * @reason: reason why this skb is dropped
*
* Drop a reference to the buffer and free it if the usage count has
- * hit zero.
+ * hit zero. Meanwhile, pass the drop reason to 'kfree_skb'
+ * tracepoint.
*/
-void kfree_skb(struct sk_buff *skb)
+void kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason)
{
if (!skb_unref(skb))
return;
- trace_kfree_skb(skb, __builtin_return_address(0));
+ trace_kfree_skb(skb, __builtin_return_address(0), reason);
__kfree_skb(skb);
}
-EXPORT_SYMBOL(kfree_skb);
+EXPORT_SYMBOL(kfree_skb_reason);
void kfree_skb_list(struct sk_buff *segs)
{