3 files changed, 174 insertions, 0 deletions

diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 844164dca90a..ee5e5b1b9282 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -49,6 +49,7 @@ obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
 ifeq ($(CONFIG_BLOCK),y)
 obj-$(CONFIG_EVENT_TRACING) += blktrace.o
 endif
+obj-$(CONFIG_SKB_SOURCES_TRACER) += trace_skb_sources.o
 obj-$(CONFIG_EVENT_TRACING) += trace_events.o
 obj-$(CONFIG_EVENT_TRACING) += trace_export.o
 obj-$(CONFIG_FTRACE_SYSCALLS) += trace_syscalls.o
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)
 
diff --git a/kernel/trace/trace_skb_sources.c b/kernel/trace/trace_skb_sources.c
new file mode 100644
index 000000000000..40eb071afdb4
--- /dev/null
+++ b/kernel/trace/trace_skb_sources.c
@@ -0,0 +1,154 @@
+/*
+ * ring buffer based tracer for analyzing per-socket skb sources
+ *
+ * Neil Horman <nhorman@tuxdriver.com>
+ * Copyright (C) 2009
+ *
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/debugfs.h>
+#include <trace/events/skb.h>
+#include <linux/kallsyms.h>
+#include <linux/module.h>
+#include <linux/hardirq.h>
+#include <linux/netdevice.h>
+#include <net/sock.h>
+
+#include "trace.h"
+#include "trace_output.h"
+
+EXPORT_TRACEPOINT_SYMBOL_GPL(skb_copy_datagram_iovec);
+
+static struct trace_array *skb_trace;
+static int __read_mostly trace_skb_source_enabled;
+
+static void probe_skb_dequeue(const struct sk_buff *skb, int len)
+{
+        struct ring_buffer_event *event;
+        struct trace_skb_event *entry;
+        struct trace_array *tr = skb_trace;
+        struct net_device *dev;
+
+        if (!trace_skb_source_enabled)
+                return;
+
+        if (in_interrupt())
+                return;
+
+        event = trace_buffer_lock_reserve(tr, TRACE_SKB_SOURCE,
+                                          sizeof(*entry), 0, 0);
+        if (!event)
+                return;
+        entry = ring_buffer_event_data(event);
+
+        entry->event_data.pid = current->pid;
+        entry->event_data.anid = page_to_nid(virt_to_page(skb->data));
+        entry->event_data.cnid = cpu_to_node(smp_processor_id());
+        entry->event_data.len = len;
+        entry->event_data.rx_queue = skb->queue_mapping;
+        entry->event_data.ccpu = smp_processor_id();
+
+        dev = dev_get_by_index(sock_net(skb->sk), skb->iif);
+        if (dev) {
+                memcpy(entry->event_data.ifname, dev->name, IFNAMSIZ);
+                dev_put(dev);
+        } else {
+                strcpy(entry->event_data.ifname, "Unknown");
+        }
+
+        trace_buffer_unlock_commit(tr, event, 0, 0);
+}
+
+static int tracing_skb_source_register(void)
+{
+        int ret;
+
+        ret = register_trace_skb_copy_datagram_iovec(probe_skb_dequeue);
+        if (ret)
+                pr_info("skb source trace: Couldn't activate dequeue tracepoint");
+
+        return ret;
+}
+
+static void start_skb_source_trace(struct trace_array *tr)
+{
+        trace_skb_source_enabled = 1;
+}
+
+static void stop_skb_source_trace(struct trace_array *tr)
+{
+        trace_skb_source_enabled = 0;
+}
+
+static void skb_source_trace_reset(struct trace_array *tr)
+{
+        trace_skb_source_enabled = 0;
+        unregister_trace_skb_copy_datagram_iovec(probe_skb_dequeue);
+}
+
+
+static int skb_source_trace_init(struct trace_array *tr)
+{
+        int cpu;
+        skb_trace = tr;
+
+        trace_skb_source_enabled = 1;
+        tracing_skb_source_register();
+
+        for_each_cpu(cpu, cpu_possible_mask)
+                tracing_reset(tr, cpu);
+        return 0;
+}
+
+static enum print_line_t skb_source_print_line(struct trace_iterator *iter)
+{
+        int ret = 0;
+        struct trace_entry *entry = iter->ent;
+        struct trace_skb_event *event;
+        struct skb_record *record;
+        struct trace_seq *s = &iter->seq;
+
+        trace_assign_type(event, entry);
+        record = &event->event_data;
+        if (entry->type != TRACE_SKB_SOURCE)
+                return TRACE_TYPE_UNHANDLED;
+
+        ret = trace_seq_printf(s, "     %d      %d      %d      %s      %d      %d      %d\n",
+                        record->pid,
+                        record->anid,
+                        record->cnid,
+                        record->ifname,
+                        record->rx_queue,
+                        record->ccpu,
+                        record->len);
+
+        if (!ret)
+                return TRACE_TYPE_PARTIAL_LINE;
+
+        return TRACE_TYPE_HANDLED;
+}
+
+static void skb_source_print_header(struct seq_file *s)
+{
+        seq_puts(s, "#  PID     ANID    CNID    IFC     RXQ     CCPU    LEN\n");
+        seq_puts(s, "#   |       |       |       |       |       |       |\n");
+}
+
+static struct tracer skb_source_tracer __read_mostly =
+{
+        .name           = "skb_sources",
+        .init           = skb_source_trace_init,
+        .start          = start_skb_source_trace,
+        .stop           = stop_skb_source_trace,
+        .reset          = skb_source_trace_reset,
+        .print_line     = skb_source_print_line,
+        .print_header   = skb_source_print_header,
+};
+
+static int init_skb_source_trace(void)
+{
+        return register_tracer(&skb_source_tracer);
+}
+device_initcall(init_skb_source_trace);