Subject: [PATCH bpf-next] bpf: remove tracepoints from bpf core

From: Alexei Starovoitov <[email-masked]>
Date: Sat, 28 Apr 2018 19:56:37 -0700

tracepoints to bpf core were added as a way to provide introspection
to bpf programs and maps, but after some time it became clear that
this approach is inadequate, so prog_id, map_id and corresponding
get_next_id, get_fd_by_id, get_info_by_fd, prog_query APIs were
introduced and fully adopted by bpftool and other applications.
The tracepoints in bpf core started to rot and causing syzbot warnings:
WARNING: CPU: 0 PID: 3008 at kernel/trace/trace_event_perf.c:274
Kernel panic - not syncing: panic_on_warn set ...
perf_trace_bpf_map_keyval+0x260/0xbd0 include/trace/events/bpf.h:228
trace_bpf_map_update_elem include/trace/events/bpf.h:274 [inline]
map_update_elem kernel/bpf/syscall.c:597 [inline]
SYSC_bpf kernel/bpf/syscall.c:1478 [inline]
Hence this patch deletes tracepoints in bpf core.

Reported-by: Eric Biggers <[email-masked]>
Reported-by: syzbot <[email-masked]>
Signed-off-by: Alexei Starovoitov <[email-masked]>
---
 MAINTAINERS                |   1 -
 include/linux/bpf_trace.h  |   1 -
 include/trace/events/bpf.h | 355 ---------------------------------------------
 kernel/bpf/core.c          |   6 -
 kernel/bpf/inode.c         |  16 +-
 kernel/bpf/syscall.c       |  11 --
 6 files changed, 1 insertion(+), 389 deletions(-)
 delete mode 100644 include/trace/events/bpf.h

diff --git a/MAINTAINERS b/MAINTAINERS
index a52800867850..537fd17a211b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2727,7 +2727,6 @@ F:	Documentation/networking/filter.txt
 F:	Documentation/bpf/
 F:	include/linux/bpf*
 F:	include/linux/filter.h
-F:	include/trace/events/bpf.h
 F:	include/trace/events/xdp.h
 F:	include/uapi/linux/bpf*
 F:	include/uapi/linux/filter.h
diff --git a/include/linux/bpf_trace.h b/include/linux/bpf_trace.h
index e6fe98ae3794..ddf896abcfb6 100644
--- a/include/linux/bpf_trace.h
+++ b/include/linux/bpf_trace.h
@@ -2,7 +2,6 @@
 #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
deleted file mode 100644
index 150185647e6b..000000000000
--- a/include/trace/events/bpf.h
+++ /dev/null
@@ -1,355 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#undef TRACE_SYSTEM
-#define TRACE_SYSTEM bpf
-
-#if !defined(_TRACE_BPF_H) || defined(TRACE_HEADER_MULTI_READ)
-#define _TRACE_BPF_H
-
-/* These are only used within the BPF_SYSCALL code */
-#ifdef CONFIG_BPF_SYSCALL
-
-#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(bool, key_null)
-		__field(int, ufd)
-	),
-
-	TP_fast_assign(
-		if (key)
-			memcpy(__get_dynamic_array(key), key, map->key_size);
-		__entry->key_null = !key;
-		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,
-		  __entry->key_null ? "NULL" : __print_hex(__get_dynamic_array(key),
-							   __entry->key_len),
-		  __entry->key_trunc && !__entry->key_null ? " ..." : "",
-		  __print_hex(__get_dynamic_array(nxt), __entry->key_len),
-		  __entry->key_trunc ? " ..." : "")
-);
-#endif /* CONFIG_BPF_SYSCALL */
-#endif /* _TRACE_BPF_H */
-
-#include <trace/define_trace.h>
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index ba03ec39efb3..133bff8adda3 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1840,9 +1840,3 @@ int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
 #include <linux/bpf_trace.h>
 
 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
-
-/* These are only used within the BPF_SYSCALL code */
-#ifdef CONFIG_BPF_SYSCALL
-EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_get_type);
-EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_put_rcu);
-#endif
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index a41343009ccc..ed13645bd80c 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -429,13 +429,6 @@ int bpf_obj_pin_user(u32 ufd, const char __user *pathname)
 	ret = bpf_obj_do_pin(pname, raw, type);
 	if (ret != 0)
 		bpf_any_put(raw, type);
-	if ((trace_bpf_obj_pin_prog_enabled() ||
-	     trace_bpf_obj_pin_map_enabled()) && !ret) {
-		if (type == BPF_TYPE_PROG)
-			trace_bpf_obj_pin_prog(raw, ufd, pname);
-		if (type == BPF_TYPE_MAP)
-			trace_bpf_obj_pin_map(raw, ufd, pname);
-	}
 out:
 	putname(pname);
 	return ret;
@@ -502,15 +495,8 @@ int bpf_obj_get_user(const char __user *pathname, int flags)
 	else
 		goto out;
 
-	if (ret < 0) {
+	if (ret < 0)
 		bpf_any_put(raw, type);
-	} else if (trace_bpf_obj_get_prog_enabled() ||
-		   trace_bpf_obj_get_map_enabled()) {
-		if (type == BPF_TYPE_PROG)
-			trace_bpf_obj_get_prog(raw, ret, pname);
-		if (type == BPF_TYPE_MAP)
-			trace_bpf_obj_get_map(raw, ret, pname);
-	}
 out:
 	putname(pname);
 	return ret;
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 0bd2944eafb9..4388fac70685 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -503,7 +503,6 @@ static int map_create(union bpf_attr *attr)
 		return err;
 	}
 
-	trace_bpf_map_create(map, err);
 	return err;
 
 free_map:
@@ -663,7 +662,6 @@ static int map_lookup_elem(union bpf_attr *attr)
 	if (copy_to_user(uvalue, value, value_size) != 0)
 		goto free_value;
 
-	trace_bpf_map_lookup_elem(map, ufd, key, value);
 	err = 0;
 
 free_value:
@@ -760,8 +758,6 @@ static int map_update_elem(union bpf_attr *attr)
 	__this_cpu_dec(bpf_prog_active);
 	preempt_enable();
 out:
-	if (!err)
-		trace_bpf_map_update_elem(map, ufd, key, value);
 free_value:
 	kfree(value);
 free_key:
@@ -814,8 +810,6 @@ static int map_delete_elem(union bpf_attr *attr)
 	__this_cpu_dec(bpf_prog_active);
 	preempt_enable();
 out:
-	if (!err)
-		trace_bpf_map_delete_elem(map, ufd, key);
 	kfree(key);
 err_put:
 	fdput(f);
@@ -879,7 +873,6 @@ static int map_get_next_key(union bpf_attr *attr)
 	if (copy_to_user(unext_key, next_key, map->key_size) != 0)
 		goto free_next_key;
 
-	trace_bpf_map_next_key(map, ufd, key, next_key);
 	err = 0;
 
 free_next_key:
@@ -1027,7 +1020,6 @@ static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
 	if (atomic_dec_and_test(&prog->aux->refcnt)) {
 		int i;
 
-		trace_bpf_prog_put_rcu(prog);
 		/* bpf_prog_free_id() must be called first */
 		bpf_prog_free_id(prog, do_idr_lock);
 
@@ -1196,8 +1188,6 @@ struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
 {
 	struct bpf_prog *prog = __bpf_prog_get(ufd, &type, attach_drv);
 
-	if (!IS_ERR(prog))
-		trace_bpf_prog_get_type(prog);
 	return prog;
 }
 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
@@ -1373,7 +1363,6 @@ static int bpf_prog_load(union bpf_attr *attr)
 	}
 
 	bpf_prog_kallsyms_add(prog);
-	trace_bpf_prog_load(prog, err);
 	return err;
 
 free_used_maps:
-- 
2.9.5