[tip:perf/urgent] perf bpf: Add wrappers to BPF_FUNC_probe_read(_str) functions

[tip-bot for Arnaldo Carvalho de Melo]

Commit-ID:  8fa25f303adfed6eab921db8e242e59dd0b3b004
Gitweb:     https://git.kernel.org/tip/8fa25f303adfed6eab921db8e242e59dd0b3b004
Author:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Tue, 7 Aug 2018 15:10:19 -0300
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 8 Aug 2018 15:55:57 -0300

perf bpf: Add wrappers to BPF_FUNC_probe_read(_str) functions

Will be used shortly in the augmented syscalls work together with a
PERF_COUNT_SW_BPF_OUTPUT software event to insert syscalls + pointer
contents in the perf ring buffer, to be consumed by 'perf trace'
beautifiers.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: https://lkml.kernel.org/n/tip-ajlkpz4cd688ulx1u30htkj3@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/include/bpf/bpf.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/perf/include/bpf/bpf.h b/tools/perf/include/bpf/bpf.h
index 1f632b56bb34..47897d65e799 100644
--- a/tools/perf/include/bpf/bpf.h
+++ b/tools/perf/include/bpf/bpf.h
@@ -30,4 +30,7 @@ struct bpf_map {
 char _license[] SEC("license") = #name; \
 int _version SEC("version") = LINUX_VERSION_CODE;
 
+static int (*probe_read)(void *dst, int size, const void *unsafe_addr) = (void *)BPF_FUNC_probe_read;
+static int (*probe_read_str)(void *dst, int size, const void *unsafe_addr) = (void *)BPF_FUNC_probe_read_str;
+
 #endif /* _PERF_BPF_H */