net: skb ftracer - Add actual ftrace code to kernel (v3)

skb allocation / consumption correlator

Add ftracer module to kernel to print out a list that correlates a process id,
an skb it read, and the numa nodes on wich the process was running when it was
read along with the numa node the skbuff was allocated on.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>

 Makefile            |    1
 trace.h             |   19 ++++++
 trace_skb_sources.c |  154 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 174 insertions(+)
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 19 insertions, 0 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 8b9f4f6e9559..8a6281b2330b 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -11,6 +11,7 @@
 #include <trace/boot.h>
 #include <linux/kmemtrace.h>
 #include <trace/power.h>
+#include <trace/events/skb.h>
 
 #include <linux/trace_seq.h>
 #include <linux/ftrace_event.h>
@@ -40,6 +41,7 @@ enum trace_type {
         TRACE_KMEM_FREE,
         TRACE_POWER,
         TRACE_BLK,
+        TRACE_SKB_SOURCE,
 
         __TRACE_LAST_TYPE,
 };
@@ -171,6 +173,21 @@ struct trace_power {
         struct power_trace      state_data;
 };
 
+struct skb_record {
+        pid_t pid;              /* pid of the copying process */
+        int anid;               /* node where skb was allocated */
+        int cnid;               /* node to which skb was copied in userspace */
+        char ifname[IFNAMSIZ];  /* Name of the receiving interface */
+        int rx_queue;           /* The rx queue the skb was received on */
+        int ccpu;               /* Cpu the application got this frame from */
+        int len;                /* length of the data copied */
+};
+
+struct trace_skb_event {
+        struct trace_entry      ent;
+        struct skb_record       event_data;
+};
+
 enum kmemtrace_type_id {
         KMEMTRACE_TYPE_KMALLOC = 0,     /* kmalloc() or kfree(). */
         KMEMTRACE_TYPE_CACHE,           /* kmem_cache_*(). */
@@ -323,6 +340,8 @@ extern void __ftrace_bad_type(void);
                           TRACE_SYSCALL_ENTER);                         \
                 IF_ASSIGN(var, ent, struct syscall_trace_exit,          \
                           TRACE_SYSCALL_EXIT);                          \
+                IF_ASSIGN(var, ent, struct trace_skb_event,             \
+                          TRACE_SKB_SOURCE);                            \
                 __ftrace_bad_type();                                    \
         } while (0)