bpf: add initial bpf tracepoints

This work adds a number of tracepoints to paths that are either
considered slow-path or exception-like states, where monitoring or
inspecting them would be desirable.

For bpf(2) syscall, tracepoints have been placed for main commands
when they succeed. In XDP case, tracepoint is for exceptions, that
is, f.e. on abnormal BPF program exit such as unknown or XDP_ABORTED
return code, or when error occurs during XDP_TX action and the packet
could not be forwarded.

Both have been split into separate event headers, and can be further
extended. Worst case, if they unexpectedly should get into our way in
future, they can also removed [1]. Of course, these tracepoints (like
any other) can be analyzed by eBPF itself, etc. Example output:

  # ./perf record -a -e bpf:* sleep 10
  # ./perf script
  sock_example  6197 [005]   283.980322:      bpf:bpf_map_create: map type=ARRAY ufd=4 key=4 val=8 max=256 flags=0
  sock_example  6197 [005]   283.980721:       bpf:bpf_prog_load: prog=a5ea8fa30ea6849c type=SOCKET_FILTER ufd=5
  sock_example  6197 [005]   283.988423:   bpf:bpf_prog_get_type: prog=a5ea8fa30ea6849c type=SOCKET_FILTER
  sock_example  6197 [005]   283.988443: bpf:bpf_map_lookup_elem: map type=ARRAY ufd=4 key=[06 00 00 00] val=[00 00 00 00 00 00 00 00]
  [...]
  sock_example  6197 [005]   288.990868: bpf:bpf_map_lookup_elem: map type=ARRAY ufd=4 key=[01 00 00 00] val=[14 00 00 00 00 00 00 00]
       swapper     0 [005]   289.338243:    bpf:bpf_prog_put_rcu: prog=a5ea8fa30ea6849c type=SOCKET_FILTER

  [1] https://lwn.net/Articles/705270/

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 407 insertions, 0 deletions

diff --git a/include/linux/bpf_trace.h b/include/linux/bpf_trace.h
new file mode 100644
index 000000000000..b22efbdd2eb4
--- /dev/null
+++ b/include/linux/bpf_trace.h
@@ -0,0 +1,7 @@
+#ifndef __LINUX_BPF_TRACE_H__
+#define __LINUX_BPF_TRACE_H__
+
+#include <trace/events/bpf.h>
+#include <trace/events/xdp.h>
+
+#endif /* __LINUX_BPF_TRACE_H__ */
diff --git a/include/trace/events/bpf.h b/include/trace/events/bpf.h
new file mode 100644
index 000000000000..c3a53fd47ff1
--- /dev/null
+++ b/include/trace/events/bpf.h
@@ -0,0 +1,347 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM bpf
+
+#if !defined(_TRACE_BPF_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_BPF_H
+
+#include <linux/filter.h>
+#include <linux/bpf.h>
+#include <linux/fs.h>
+#include <linux/tracepoint.h>
+
+#define __PROG_TYPE_MAP(FN)	\
+	FN(SOCKET_FILTER)	\
+	FN(KPROBE)		\
+	FN(SCHED_CLS)		\
+	FN(SCHED_ACT)		\
+	FN(TRACEPOINT)		\
+	FN(XDP)			\
+	FN(PERF_EVENT)		\
+	FN(CGROUP_SKB)		\
+	FN(CGROUP_SOCK)		\
+	FN(LWT_IN)		\
+	FN(LWT_OUT)		\
+	FN(LWT_XMIT)
+
+#define __MAP_TYPE_MAP(FN)	\
+	FN(HASH)		\
+	FN(ARRAY)		\
+	FN(PROG_ARRAY)		\
+	FN(PERF_EVENT_ARRAY)	\
+	FN(PERCPU_HASH)		\
+	FN(PERCPU_ARRAY)	\
+	FN(STACK_TRACE)		\
+	FN(CGROUP_ARRAY)	\
+	FN(LRU_HASH)		\
+	FN(LRU_PERCPU_HASH)	\
+	FN(LPM_TRIE)
+
+#define __PROG_TYPE_TP_FN(x)	\
+	TRACE_DEFINE_ENUM(BPF_PROG_TYPE_##x);
+#define __PROG_TYPE_SYM_FN(x)	\
+	{ BPF_PROG_TYPE_##x, #x },
+#define __PROG_TYPE_SYM_TAB	\
+	__PROG_TYPE_MAP(__PROG_TYPE_SYM_FN) { -1, 0 }
+__PROG_TYPE_MAP(__PROG_TYPE_TP_FN)
+
+#define __MAP_TYPE_TP_FN(x)	\
+	TRACE_DEFINE_ENUM(BPF_MAP_TYPE_##x);
+#define __MAP_TYPE_SYM_FN(x)	\
+	{ BPF_MAP_TYPE_##x, #x },
+#define __MAP_TYPE_SYM_TAB	\
+	__MAP_TYPE_MAP(__MAP_TYPE_SYM_FN) { -1, 0 }
+__MAP_TYPE_MAP(__MAP_TYPE_TP_FN)
+
+DECLARE_EVENT_CLASS(bpf_prog_event,
+
+	TP_PROTO(const struct bpf_prog *prg),
+
+	TP_ARGS(prg),
+
+	TP_STRUCT__entry(
+		__array(u8, prog_tag, 8)
+		__field(u32, type)
+	),
+
+	TP_fast_assign(
+		BUILD_BUG_ON(sizeof(__entry->prog_tag) != sizeof(prg->tag));
+		memcpy(__entry->prog_tag, prg->tag, sizeof(prg->tag));
+		__entry->type = prg->type;
+	),
+
+	TP_printk("prog=%s type=%s",
+		  __print_hex_str(__entry->prog_tag, 8),
+		  __print_symbolic(__entry->type, __PROG_TYPE_SYM_TAB))
+);
+
+DEFINE_EVENT(bpf_prog_event, bpf_prog_get_type,
+
+	TP_PROTO(const struct bpf_prog *prg),
+
+	TP_ARGS(prg)
+);
+
+DEFINE_EVENT(bpf_prog_event, bpf_prog_put_rcu,
+
+	TP_PROTO(const struct bpf_prog *prg),
+
+	TP_ARGS(prg)
+);
+
+TRACE_EVENT(bpf_prog_load,
+
+	TP_PROTO(const struct bpf_prog *prg, int ufd),
+
+	TP_ARGS(prg, ufd),
+
+	TP_STRUCT__entry(
+		__array(u8, prog_tag, 8)
+		__field(u32, type)
+		__field(int, ufd)
+	),
+
+	TP_fast_assign(
+		BUILD_BUG_ON(sizeof(__entry->prog_tag) != sizeof(prg->tag));
+		memcpy(__entry->prog_tag, prg->tag, sizeof(prg->tag));
+		__entry->type = prg->type;
+		__entry->ufd  = ufd;
+	),
+
+	TP_printk("prog=%s type=%s ufd=%d",
+		  __print_hex_str(__entry->prog_tag, 8),
+		  __print_symbolic(__entry->type, __PROG_TYPE_SYM_TAB),
+		  __entry->ufd)
+);
+
+TRACE_EVENT(bpf_map_create,
+
+	TP_PROTO(const struct bpf_map *map, int ufd),
+
+	TP_ARGS(map, ufd),
+
+	TP_STRUCT__entry(
+		__field(u32, type)
+		__field(u32, size_key)
+		__field(u32, size_value)
+		__field(u32, max_entries)
+		__field(u32, flags)
+		__field(int, ufd)
+	),
+
+	TP_fast_assign(
+		__entry->type        = map->map_type;
+		__entry->size_key    = map->key_size;
+		__entry->size_value  = map->value_size;
+		__entry->max_entries = map->max_entries;
+		__entry->flags       = map->map_flags;
+		__entry->ufd         = ufd;
+	),
+
+	TP_printk("map type=%s ufd=%d key=%u val=%u max=%u flags=%x",
+		  __print_symbolic(__entry->type, __MAP_TYPE_SYM_TAB),
+		  __entry->ufd, __entry->size_key, __entry->size_value,
+		  __entry->max_entries, __entry->flags)
+);
+
+DECLARE_EVENT_CLASS(bpf_obj_prog,
+
+	TP_PROTO(const struct bpf_prog *prg, int ufd,
+		 const struct filename *pname),
+
+	TP_ARGS(prg, ufd, pname),
+
+	TP_STRUCT__entry(
+		__array(u8, prog_tag, 8)
+		__field(int, ufd)
+		__string(path, pname->name)
+	),
+
+	TP_fast_assign(
+		BUILD_BUG_ON(sizeof(__entry->prog_tag) != sizeof(prg->tag));
+		memcpy(__entry->prog_tag, prg->tag, sizeof(prg->tag));
+		__assign_str(path, pname->name);
+		__entry->ufd = ufd;
+	),
+
+	TP_printk("prog=%s path=%s ufd=%d",
+		  __print_hex_str(__entry->prog_tag, 8),
+		  __get_str(path), __entry->ufd)
+);
+
+DEFINE_EVENT(bpf_obj_prog, bpf_obj_pin_prog,
+
+	TP_PROTO(const struct bpf_prog *prg, int ufd,
+		 const struct filename *pname),
+
+	TP_ARGS(prg, ufd, pname)
+);
+
+DEFINE_EVENT(bpf_obj_prog, bpf_obj_get_prog,
+
+	TP_PROTO(const struct bpf_prog *prg, int ufd,
+		 const struct filename *pname),
+
+	TP_ARGS(prg, ufd, pname)
+);
+
+DECLARE_EVENT_CLASS(bpf_obj_map,
+
+	TP_PROTO(const struct bpf_map *map, int ufd,
+		 const struct filename *pname),
+
+	TP_ARGS(map, ufd, pname),
+
+	TP_STRUCT__entry(
+		__field(u32, type)
+		__field(int, ufd)
+		__string(path, pname->name)
+	),
+
+	TP_fast_assign(
+		__assign_str(path, pname->name);
+		__entry->type = map->map_type;
+		__entry->ufd  = ufd;
+	),
+
+	TP_printk("map type=%s ufd=%d path=%s",
+		  __print_symbolic(__entry->type, __MAP_TYPE_SYM_TAB),
+		  __entry->ufd, __get_str(path))
+);
+
+DEFINE_EVENT(bpf_obj_map, bpf_obj_pin_map,
+
+	TP_PROTO(const struct bpf_map *map, int ufd,
+		 const struct filename *pname),
+
+	TP_ARGS(map, ufd, pname)
+);
+
+DEFINE_EVENT(bpf_obj_map, bpf_obj_get_map,
+
+	TP_PROTO(const struct bpf_map *map, int ufd,
+		 const struct filename *pname),
+
+	TP_ARGS(map, ufd, pname)
+);
+
+DECLARE_EVENT_CLASS(bpf_map_keyval,
+
+	TP_PROTO(const struct bpf_map *map, int ufd,
+		 const void *key, const void *val),
+
+	TP_ARGS(map, ufd, key, val),
+
+	TP_STRUCT__entry(
+		__field(u32, type)
+		__field(u32, key_len)
+		__dynamic_array(u8, key, map->key_size)
+		__field(bool, key_trunc)
+		__field(u32, val_len)
+		__dynamic_array(u8, val, map->value_size)
+		__field(bool, val_trunc)
+		__field(int, ufd)
+	),
+
+	TP_fast_assign(
+		memcpy(__get_dynamic_array(key), key, map->key_size);
+		memcpy(__get_dynamic_array(val), val, map->value_size);
+		__entry->type      = map->map_type;
+		__entry->key_len   = min(map->key_size, 16U);
+		__entry->key_trunc = map->key_size != __entry->key_len;
+		__entry->val_len   = min(map->value_size, 16U);
+		__entry->val_trunc = map->value_size != __entry->val_len;
+		__entry->ufd       = ufd;
+	),
+
+	TP_printk("map type=%s ufd=%d key=[%s%s] val=[%s%s]",
+		  __print_symbolic(__entry->type, __MAP_TYPE_SYM_TAB),
+		  __entry->ufd,
+		  __print_hex(__get_dynamic_array(key), __entry->key_len),
+		  __entry->key_trunc ? " ..." : "",
+		  __print_hex(__get_dynamic_array(val), __entry->val_len),
+		  __entry->val_trunc ? " ..." : "")
+);
+
+DEFINE_EVENT(bpf_map_keyval, bpf_map_lookup_elem,
+
+	TP_PROTO(const struct bpf_map *map, int ufd,
+		 const void *key, const void *val),
+
+	TP_ARGS(map, ufd, key, val)
+);
+
+DEFINE_EVENT(bpf_map_keyval, bpf_map_update_elem,
+
+	TP_PROTO(const struct bpf_map *map, int ufd,
+		 const void *key, const void *val),
+
+	TP_ARGS(map, ufd, key, val)
+);
+
+TRACE_EVENT(bpf_map_delete_elem,
+
+	TP_PROTO(const struct bpf_map *map, int ufd,
+		 const void *key),
+
+	TP_ARGS(map, ufd, key),
+
+	TP_STRUCT__entry(
+		__field(u32, type)
+		__field(u32, key_len)
+		__dynamic_array(u8, key, map->key_size)
+		__field(bool, key_trunc)
+		__field(int, ufd)
+	),
+
+	TP_fast_assign(
+		memcpy(__get_dynamic_array(key), key, map->key_size);
+		__entry->type      = map->map_type;
+		__entry->key_len   = min(map->key_size, 16U);
+		__entry->key_trunc = map->key_size != __entry->key_len;
+		__entry->ufd       = ufd;
+	),
+
+	TP_printk("map type=%s ufd=%d key=[%s%s]",
+		  __print_symbolic(__entry->type, __MAP_TYPE_SYM_TAB),
+		  __entry->ufd,
+		  __print_hex(__get_dynamic_array(key), __entry->key_len),
+		  __entry->key_trunc ? " ..." : "")
+);
+
+TRACE_EVENT(bpf_map_next_key,
+
+	TP_PROTO(const struct bpf_map *map, int ufd,
+		 const void *key, const void *key_next),
+
+	TP_ARGS(map, ufd, key, key_next),
+
+	TP_STRUCT__entry(
+		__field(u32, type)
+		__field(u32, key_len)
+		__dynamic_array(u8, key, map->key_size)
+		__dynamic_array(u8, nxt, map->key_size)
+		__field(bool, key_trunc)
+		__field(int, ufd)
+	),
+
+	TP_fast_assign(
+		memcpy(__get_dynamic_array(key), key, map->key_size);
+		memcpy(__get_dynamic_array(nxt), key_next, map->key_size);
+		__entry->type      = map->map_type;
+		__entry->key_len   = min(map->key_size, 16U);
+		__entry->key_trunc = map->key_size != __entry->key_len;
+		__entry->ufd       = ufd;
+	),
+
+	TP_printk("map type=%s ufd=%d key=[%s%s] next=[%s%s]",
+		  __print_symbolic(__entry->type, __MAP_TYPE_SYM_TAB),
+		  __entry->ufd,
+		  __print_hex(__get_dynamic_array(key), __entry->key_len),
+		  __entry->key_trunc ? " ..." : "",
+		  __print_hex(__get_dynamic_array(nxt), __entry->key_len),
+		  __entry->key_trunc ? " ..." : "")
+);
+
+#endif /* _TRACE_BPF_H */
+
+#include <trace/define_trace.h>
diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h
new file mode 100644
index 000000000000..1b61357d3f57
--- /dev/null
+++ b/include/trace/events/xdp.h
@@ -0,0 +1,53 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM xdp
+
+#if !defined(_TRACE_XDP_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_XDP_H
+
+#include <linux/netdevice.h>
+#include <linux/filter.h>
+#include <linux/tracepoint.h>
+
+#define __XDP_ACT_MAP(FN)	\
+	FN(ABORTED)		\
+	FN(DROP)		\
+	FN(PASS)		\
+	FN(TX)
+
+#define __XDP_ACT_TP_FN(x)	\
+	TRACE_DEFINE_ENUM(XDP_##x);
+#define __XDP_ACT_SYM_FN(x)	\
+	{ XDP_##x, #x },
+#define __XDP_ACT_SYM_TAB	\
+	__XDP_ACT_MAP(__XDP_ACT_SYM_FN) { -1, 0 }
+__XDP_ACT_MAP(__XDP_ACT_TP_FN)
+
+TRACE_EVENT(xdp_exception,
+
+	TP_PROTO(const struct net_device *dev,
+		 const struct bpf_prog *xdp, u32 act),
+
+	TP_ARGS(dev, xdp, act),
+
+	TP_STRUCT__entry(
+		__string(name, dev->name)
+		__array(u8, prog_tag, 8)
+		__field(u32, act)
+	),
+
+	TP_fast_assign(
+		BUILD_BUG_ON(sizeof(__entry->prog_tag) != sizeof(xdp->tag));
+		memcpy(__entry->prog_tag, xdp->tag, sizeof(xdp->tag));
+		__assign_str(name, dev->name);
+		__entry->act = act;
+	),
+
+	TP_printk("prog=%s device=%s action=%s",
+		  __print_hex_str(__entry->prog_tag, 8),
+		  __get_str(name),
+		  __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB))
+);
+
+#endif /* _TRACE_XDP_H */
+
+#include <trace/define_trace.h>