bpf: relocates the BPF net tracepoint definitions

This commit relocates the BPF tracepoint definitions for XDP and sockmap
from the kernel directory to net/bpf.

This ensures that these tracepoints are controlled by the CONFIG_NET,
avoiding unnecessary function definitions when the CONFIG_NET is disabled.
Additionally, it prevents build failures caused by the use of net module
functions when CONFIG_NET is not enabled.

Signed-off-by: Jiayuan Chen <[email protected]>

Author: mrpre

kernel/bpf/core.c

@@ -3180,10 +3180,3 @@ late_initcall(bpf_global_ma_init);
 
 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
 EXPORT_SYMBOL(bpf_stats_enabled_key);
-
-/* All definitions of tracepoints related to BPF. */
-#define CREATE_TRACE_POINTS
-#include <linux/bpf_trace.h>
-
-EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
-EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);

net/bpf/Makefile

@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_BPF_SYSCALL)	:= test_run.o
+obj-$(CONFIG_BPF_SYSCALL)	+= bpf_net_trace.o
 ifeq ($(CONFIG_BPF_JIT),y)
 obj-$(CONFIG_BPF_SYSCALL)	+= bpf_dummy_struct_ops.o
 endif

net/bpf/bpf_net_trace.c

@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/* All definitions of net tracepoints related to BPF. */
+#define CREATE_TRACE_POINTS
+#include <linux/bpf_trace.h>
+
+EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
+EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);