From: Wang Nan <wangnan0@huawei.com>
Date: Mon, 16 Nov 2015 12:10:06 +0000 (+0000)
Subject: perf bpf: Allow attaching BPF programs to modules symbols
X-Git-Tag: v4.5-rc1~171^2~43^2~28
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5dbd16c0c9d17ab1ab2226a5926482c26c0287ed;p=karo-tx-linux.git

perf bpf: Allow attaching BPF programs to modules symbols

By extending the syntax of BPF object section names, this patch allows
users to attach BPF programs to symbols in modules. For example:

  SEC("module=i915;"
      "parse_cmds=i915_parse_cmds")
  int parse_cmds(void *ctx)
  {
      return 1;
  }

The implementation is very simple: like what 'perf probe' does, for module,
fill 'uprobe' field in 'struct perf_probe_event'. Other parts will be done
automatically.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1447675815-166222-5-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 84169d6f2585..d0f02ed93804 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -119,6 +119,16 @@ config__exec(const char *value, struct perf_probe_event *pev)
 	return 0;
 }
 
+static int
+config__module(const char *value, struct perf_probe_event *pev)
+{
+	pev->uprobes = false;
+	pev->target = strdup(value);
+	if (!pev->target)
+		return -ENOMEM;
+	return 0;
+}
+
 static struct {
 	const char *key;
 	const char *usage;
@@ -131,6 +141,12 @@ static struct {
 		.desc	= "Set uprobe target",
 		.func	= config__exec,
 	},
+	{
+		.key	= "module",
+		.usage	= "module=<module name>    ",
+		.desc	= "Set kprobe module",
+		.func	= config__module,
+	}
 };
 
 static int