Commit 4d220ed0 authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Daniel Borkmann
Browse files

bpf: remove tracepoints from bpf core 



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: default avatarEric Biggers <ebiggers3@gmail.com>
Reported-by: default avatarsyzbot <bot+a9dbb3c3e64b62536a4bc5ee7bbd4ca627566188@syzkaller.appspotmail.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 34745aed

MAINTAINERS

+0 −1
Original line number Diff line number Diff line
@@ -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

include/linux/bpf_trace.h

+0 −1
Original line number Diff line number Diff line
@@ -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__ */

include/trace/events/bpf.h

deleted100644 → 0
+0 −355
Original line number Diff line number Diff line 
/* 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>

kernel/bpf/core.c

+0 −6
Original line number Diff line number Diff line
@@ -1845,9 +1845,3 @@ 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

kernel/bpf/inode.c

+1 −15
Original line number Diff line number Diff line
@@ -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;

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