[tip:perf/core] tools lib bpf: Make bpf_program__get_private() use IS_ERR()

[tip-bot for Arnaldo Carvalho de Melo]

Commit-ID:  be834ffbd15ea9d73ba96fdbdcb1012add7e3bdf
Gitweb:     http://git.kernel.org/tip/be834ffbd15ea9d73ba96fdbdcb1012add7e3bdf
Author:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Fri, 3 Jun 2016 12:36:39 -0300
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 6 Jun 2016 18:19:34 -0300

tools lib bpf: Make bpf_program__get_private() use IS_ERR()

For consistency with bpf_map__priv() and elsewhere.

Acked-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Milian Wolff <milian.wolff@xxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-x17nk5mrazkf45z0l0ahlmo8@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/lib/bpf/libbpf.c       |  5 ++---
 tools/lib/bpf/libbpf.h       |  3 +--
 tools/perf/util/bpf-loader.c | 27 ++++++++++++---------------
 3 files changed, 15 insertions(+), 20 deletions(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 0412182..7eb7fb2 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1230,10 +1230,9 @@ int bpf_program__set_private(struct bpf_program *prog,
 	return 0;
 }
 
-int bpf_program__get_private(struct bpf_program *prog, void **ppriv)
+void *bpf_program__priv(struct bpf_program *prog)
 {
-	*ppriv = prog->priv;
-	return 0;
+	return prog ? prog->priv : ERR_PTR(-EINVAL);
 }
 
 const char *bpf_program__title(struct bpf_program *prog, bool needs_copy)
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index ea65775..372cecb 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -81,8 +81,7 @@ typedef void (*bpf_program_clear_priv_t)(struct bpf_program *,
 int bpf_program__set_private(struct bpf_program *prog, void *priv,
 			     bpf_program_clear_priv_t clear_priv);
 
-int bpf_program__get_private(struct bpf_program *prog,
-			     void **ppriv);
+void *bpf_program__priv(struct bpf_program *prog);
 
 const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
 
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index c19010e..1907d53 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -380,15 +380,14 @@ preproc_gen_prologue(struct bpf_program *prog, int n,
 		     struct bpf_insn *orig_insns, int orig_insns_cnt,
 		     struct bpf_prog_prep_result *res)
 {
+	struct bpf_prog_priv *priv = bpf_program__priv(prog);
 	struct probe_trace_event *tev;
 	struct perf_probe_event *pev;
-	struct bpf_prog_priv *priv;
 	struct bpf_insn *buf;
 	size_t prologue_cnt = 0;
 	int i, err;
 
-	err = bpf_program__get_private(prog, (void **)&priv);
-	if (err || !priv)
+	if (IS_ERR(priv) || !priv)
 		goto errout;
 
 	pev = &priv->pev;
@@ -535,13 +534,12 @@ static int map_prologue(struct perf_probe_event *pev, int *mapping,
 
 static int hook_load_preprocessor(struct bpf_program *prog)
 {
+	struct bpf_prog_priv *priv = bpf_program__priv(prog);
 	struct perf_probe_event *pev;
-	struct bpf_prog_priv *priv;
 	bool need_prologue = false;
 	int err, i;
 
-	err = bpf_program__get_private(prog, (void **)&priv);
-	if (err || !priv) {
+	if (IS_ERR(priv) || !priv) {
 		pr_debug("Internal error when hook preprocessor\n");
 		return -BPF_LOADER_ERRNO__INTERNAL;
 	}
@@ -607,9 +605,11 @@ int bpf__probe(struct bpf_object *obj)
 		if (err)
 			goto out;
 
-		err = bpf_program__get_private(prog, (void **)&priv);
-		if (err || !priv)
+		priv = bpf_program__priv(prog);
+		if (IS_ERR(priv) || !priv) {
+			err = PTR_ERR(priv);
 			goto out;
+		}
 		pev = &priv->pev;
 
 		err = convert_perf_probe_events(pev, 1);
@@ -645,13 +645,12 @@ int bpf__unprobe(struct bpf_object *obj)
 {
 	int err, ret = 0;
 	struct bpf_program *prog;
-	struct bpf_prog_priv *priv;
 
 	bpf_object__for_each_program(prog, obj) {
+		struct bpf_prog_priv *priv = bpf_program__priv(prog);
 		int i;
 
-		err = bpf_program__get_private(prog, (void **)&priv);
-		if (err || !priv)
+		if (IS_ERR(priv) || !priv)
 			continue;
 
 		for (i = 0; i < priv->pev.ntevs; i++) {
@@ -702,14 +701,12 @@ int bpf__foreach_tev(struct bpf_object *obj,
 	int err;
 
 	bpf_object__for_each_program(prog, obj) {
+		struct bpf_prog_priv *priv = bpf_program__priv(prog);
 		struct probe_trace_event *tev;
 		struct perf_probe_event *pev;
-		struct bpf_prog_priv *priv;
 		int i, fd;
 
-		err = bpf_program__get_private(prog,
-				(void **)&priv);
-		if (err || !priv) {
+		if (IS_ERR(priv) || !priv) {
 			pr_debug("bpf: failed to get private field\n");
 			return -BPF_LOADER_ERRNO__INTERNAL;
 		}