tracing: bpf: Hide bpf trace events when they are not used (9185a610) · Commits · 戴 / test

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>

include/trace/events/bpf.h

+4 −1

Original line number	Diff line number	Diff line
		@@ -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>

kernel/bpf/core.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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

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