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tracing: bpf: Hide bpf trace events when they are not used

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All the trace events defined in include/trace/events/bpf.h are only
used when CONFIG_BPF_SYSCALL is defined. But this file gets included by
include/linux/bpf_trace.h which is included by the networking code with
CREATE_TRACE_POINTS defined.

If a trace event is created but not used it still has data structures
and functions created for its use, even though nothing is using them.
To not waste space, do not define the BPF trace events in bpf.h unless
CONFIG_BPF_SYSCALL is defined.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Steven Rostedt (VMware) 2017-10-12 18:40:02 -04:00 committed by David S. Miller
parent 0da4af00b2
commit 9185a610f8
2 changed files with 7 additions and 1 deletions
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5
include/trace/events/bpf.h
View File

@ -4,6 +4,9 @@
#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>
@ -345,7 +348,7 @@ TRACE_EVENT(bpf_map_next_key,
__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>

3
kernel/bpf/core.c
View File

@ -1580,5 +1580,8 @@ int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
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