bpf: support bpf_get_stackid() and bpf_perf_event_output() in tracepoint programs

needs two wrapper functions to fetch 'struct pt_regs *' to convert
tracepoint bpf context into kprobe bpf context to reuse existing
helper functions

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 21ee41b..198f6ac 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -160,6 +160,7 @@
 #define MAX_TAIL_CALL_CNT 32
 
 u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5);
+u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
 void bpf_fd_array_map_clear(struct bpf_map *map);
 bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp);
 const struct bpf_func_proto *bpf_get_trace_printk_proto(void);