perf evsel: Propagate error info from tp_format

Propagate error info from tp_format via ERR_PTR to get it all the way
down to the parse-event.c tracepoint adding routines. Following
functions now return pointer with encoded error:

  - tp_format
  - trace_event__tp_format
  - perf_evsel__newtp_idx
  - perf_evsel__newtp

This affects several other places in perf, that cannot use pointer check
anymore, but must utilize the err.h interface, when getting error
information from above functions list.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Raphael Beamonte <raphael.beamonte@gmail.com>
Link: http://lkml.kernel.org/r/1441615087-13886-5-git-send-email-jolsa@kernel.org
[ Add two missing ERR_PTR() and one IS_ERR() ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

11 files changed, 60 insertions, 24 deletions

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 215653274102..93b80f12f35e 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -38,6 +38,7 @@
 #include <stdlib.h>
 #include <sys/mman.h>
 #include <linux/futex.h>
+#include <linux/err.h>
 
 /* For older distros: */
 #ifndef MAP_STACK
@@ -245,13 +246,14 @@ static struct perf_evsel *perf_evsel__syscall_newtp(const char *direction, void
         struct perf_evsel *evsel = perf_evsel__newtp("raw_syscalls", direction);
 
         /* older kernel (e.g., RHEL6) use syscalls:{enter,exit} */
-        if (evsel == NULL)
+        if (IS_ERR(evsel))
                 evsel = perf_evsel__newtp("syscalls", direction);
 
-        if (evsel) {
-                if (perf_evsel__init_syscall_tp(evsel, handler))
-                        goto out_delete;
-        }
+        if (IS_ERR(evsel))
+                return NULL;
+
+        if (perf_evsel__init_syscall_tp(evsel, handler))
+                goto out_delete;
 
         return evsel;
 
@@ -1705,12 +1707,12 @@ static int trace__read_syscall_info(struct trace *trace, int id)
         snprintf(tp_name, sizeof(tp_name), "sys_enter_%s", sc->name);
         sc->tp_format = trace_event__tp_format("syscalls", tp_name);
 
-        if (sc->tp_format == NULL && sc->fmt && sc->fmt->alias) {
+        if (IS_ERR(sc->tp_format) && sc->fmt && sc->fmt->alias) {
                 snprintf(tp_name, sizeof(tp_name), "sys_enter_%s", sc->fmt->alias);
                 sc->tp_format = trace_event__tp_format("syscalls", tp_name);
         }
 
-        if (sc->tp_format == NULL)
+        if (IS_ERR(sc->tp_format))
                 return -1;
 
         sc->args = sc->tp_format->format.fields;
@@ -2390,7 +2392,8 @@ static size_t trace__fprintf_thread_summary(struct trace *trace, FILE *fp);
 static bool perf_evlist__add_vfs_getname(struct perf_evlist *evlist)
 {
         struct perf_evsel *evsel = perf_evsel__newtp("probe", "vfs_getname");
-        if (evsel == NULL)
+
+        if (IS_ERR(evsel))
                 return false;
 
         if (perf_evsel__field(evsel, "pathname") == NULL) {
diff --git a/tools/perf/tests/evsel-tp-sched.c b/tools/perf/tests/evsel-tp-sched.c
index 52162425c969..790e413d9a1f 100644
--- a/tools/perf/tests/evsel-tp-sched.c
+++ b/tools/perf/tests/evsel-tp-sched.c
@@ -1,3 +1,4 @@
+#include <linux/err.h>
 #include <traceevent/event-parse.h>
 #include "evsel.h"
 #include "tests.h"
@@ -36,8 +37,8 @@ int test__perf_evsel__tp_sched_test(void)
         struct perf_evsel *evsel = perf_evsel__newtp("sched", "sched_switch");
         int ret = 0;
 
-        if (evsel == NULL) {
-                pr_debug("perf_evsel__new\n");
+        if (IS_ERR(evsel)) {
+                pr_debug("perf_evsel__newtp failed with %ld\n", PTR_ERR(evsel));
                 return -1;
         }
 
@@ -66,6 +67,11 @@ int test__perf_evsel__tp_sched_test(void)
 
         evsel = perf_evsel__newtp("sched", "sched_wakeup");
 
+        if (IS_ERR(evsel)) {
+                pr_debug("perf_evsel__newtp failed with %ld\n", PTR_ERR(evsel));
+                return -1;
+        }
+
         if (perf_evsel__test_field(evsel, "comm", 16, true))
                 ret = -1;
 
diff --git a/tools/perf/tests/mmap-basic.c b/tools/perf/tests/mmap-basic.c
index 666b67a4df9d..4495493c9431 100644
--- a/tools/perf/tests/mmap-basic.c
+++ b/tools/perf/tests/mmap-basic.c
@@ -3,6 +3,7 @@
 #include "thread_map.h"
 #include "cpumap.h"
 #include "tests.h"
+#include <linux/err.h>
 
 /*
  * This test will generate random numbers of calls to some getpid syscalls,
@@ -65,7 +66,7 @@ int test__basic_mmap(void)
 
                 snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
                 evsels[i] = perf_evsel__newtp("syscalls", name);
-                if (evsels[i] == NULL) {
+                if (IS_ERR(evsels[i])) {
                         pr_debug("perf_evsel__new\n");
                         goto out_delete_evlist;
                 }
diff --git a/tools/perf/tests/openat-syscall-all-cpus.c b/tools/perf/tests/openat-syscall-all-cpus.c
index 495d8126b722..9e104a2e973d 100644
--- a/tools/perf/tests/openat-syscall-all-cpus.c
+++ b/tools/perf/tests/openat-syscall-all-cpus.c
@@ -1,4 +1,5 @@
 #include <api/fs/fs.h>
+#include <linux/err.h>
 #include "evsel.h"
 #include "tests.h"
 #include "thread_map.h"
@@ -31,7 +32,7 @@ int test__openat_syscall_event_on_all_cpus(void)
         CPU_ZERO(&cpu_set);
 
         evsel = perf_evsel__newtp("syscalls", "sys_enter_openat");
-        if (evsel == NULL) {
+        if (IS_ERR(evsel)) {
                 tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "syscalls", "sys_enter_openat");
                 pr_err("%s\n", errbuf);
                 goto out_thread_map_delete;
diff --git a/tools/perf/tests/openat-syscall-tp-fields.c b/tools/perf/tests/openat-syscall-tp-fields.c
index 01a19626c846..473d3869727e 100644
--- a/tools/perf/tests/openat-syscall-tp-fields.c
+++ b/tools/perf/tests/openat-syscall-tp-fields.c
@@ -1,3 +1,4 @@
+#include <linux/err.h>
 #include "perf.h"
 #include "evlist.h"
 #include "evsel.h"
@@ -30,7 +31,7 @@ int test__syscall_openat_tp_fields(void)
         }
 
         evsel = perf_evsel__newtp("syscalls", "sys_enter_openat");
-        if (evsel == NULL) {
+        if (IS_ERR(evsel)) {
                 pr_debug("%s: perf_evsel__newtp\n", __func__);
                 goto out_delete_evlist;
         }
diff --git a/tools/perf/tests/openat-syscall.c b/tools/perf/tests/openat-syscall.c
index 08ac9d94a050..7b1db8306098 100644
--- a/tools/perf/tests/openat-syscall.c
+++ b/tools/perf/tests/openat-syscall.c
@@ -1,4 +1,5 @@
 #include <api/fs/tracing_path.h>
+#include <linux/err.h>
 #include "thread_map.h"
 #include "evsel.h"
 #include "debug.h"
@@ -19,7 +20,7 @@ int test__openat_syscall_event(void)
         }
 
         evsel = perf_evsel__newtp("syscalls", "sys_enter_openat");
-        if (evsel == NULL) {
+        if (IS_ERR(evsel)) {
                 tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "syscalls", "sys_enter_openat");
                 pr_err("%s\n", errbuf);
                 goto out_thread_map_delete;
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index d51a5200c8af..3cb2bf9bd4bd 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -25,6 +25,7 @@
 #include <linux/bitops.h>
 #include <linux/hash.h>
 #include <linux/log2.h>
+#include <linux/err.h>
 
 static void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx);
 static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx);
@@ -265,7 +266,7 @@ int perf_evlist__add_newtp(struct perf_evlist *evlist,
 {
         struct perf_evsel *evsel = perf_evsel__newtp(sys, name);
 
-        if (evsel == NULL)
+        if (IS_ERR(evsel))
                 return -1;
 
         evsel->handler = handler;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 771ade4d5966..6b5d1b509148 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -13,6 +13,7 @@
 #include <traceevent/event-parse.h>
 #include <linux/hw_breakpoint.h>
 #include <linux/perf_event.h>
+#include <linux/err.h>
 #include <sys/resource.h>
 #include "asm/bug.h"
 #include "callchain.h"
@@ -225,11 +226,17 @@ struct perf_evsel *perf_evsel__new_idx(struct perf_event_attr *attr, int idx)
         return evsel;
 }
 
+/*
+ * Returns pointer with encoded error via <linux/err.h> interface.
+ */
 struct perf_evsel *perf_evsel__newtp_idx(const char *sys, const char *name, int idx)
 {
         struct perf_evsel *evsel = zalloc(perf_evsel__object.size);
+        int err = -ENOMEM;
 
-        if (evsel != NULL) {
+        if (evsel == NULL) {
+                goto out_err;
+        } else {
                 struct perf_event_attr attr = {
                         .type          = PERF_TYPE_TRACEPOINT,
                         .sample_type   = (PERF_SAMPLE_RAW | PERF_SAMPLE_TIME |
@@ -240,8 +247,10 @@ struct perf_evsel *perf_evsel__newtp_idx(const char *sys, const char *name, int
                         goto out_free;
 
                 evsel->tp_format = trace_event__tp_format(sys, name);
-                if (evsel->tp_format == NULL)
+                if (IS_ERR(evsel->tp_format)) {
+                        err = PTR_ERR(evsel->tp_format);
                         goto out_free;
+                }
 
                 event_attr_init(&attr);
                 attr.config = evsel->tp_format->id;
@@ -254,7 +263,8 @@ struct perf_evsel *perf_evsel__newtp_idx(const char *sys, const char *name, int
 out_free:
         zfree(&evsel->name);
         free(evsel);
-        return NULL;
+out_err:
+        return ERR_PTR(err);
 }
 
 const char *perf_evsel__hw_names[PERF_COUNT_HW_MAX] = {
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index f164a149da82..62ab307b7306 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -160,6 +160,9 @@ static inline struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr)
 
 struct perf_evsel *perf_evsel__newtp_idx(const char *sys, const char *name, int idx);
 
+/*
+ * Returns pointer with encoded error via <linux/err.h> interface.
+ */
 static inline struct perf_evsel *perf_evsel__newtp(const char *sys, const char *name)
 {
         return perf_evsel__newtp_idx(sys, name, 0);
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 1b284b8ad243..c47831c47220 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -1,4 +1,5 @@
 #include <linux/hw_breakpoint.h>
+#include <linux/err.h>
 #include "util.h"
 #include "../perf.h"
 #include "evlist.h"
@@ -393,11 +394,10 @@ static int add_tracepoint(struct list_head *list, int *idx,
         struct perf_evsel *evsel;
 
         evsel = perf_evsel__newtp_idx(sys_name, evt_name, (*idx)++);
-        if (!evsel)
-                return -ENOMEM;
+        if (IS_ERR(evsel))
+                return PTR_ERR(evsel);
 
         list_add_tail(&evsel->node, list);
-
         return 0;
 }
 
diff --git a/tools/perf/util/trace-event.c b/tools/perf/util/trace-event.c
index 2f4996ab313d..802bb868d446 100644
--- a/tools/perf/util/trace-event.c
+++ b/tools/perf/util/trace-event.c
@@ -7,6 +7,7 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <linux/kernel.h>
+#include <linux/err.h>
 #include <traceevent/event-parse.h>
 #include <api/fs/tracing_path.h>
 #include "trace-event.h"
@@ -66,6 +67,9 @@ void trace_event__cleanup(struct trace_event *t)
         pevent_free(t->pevent);
 }
 
+/*
+ * Returns pointer with encoded error via <linux/err.h> interface.
+ */
 static struct event_format*
 tp_format(const char *sys, const char *name)
 {
@@ -74,12 +78,14 @@ tp_format(const char *sys, const char *name)
         char path[PATH_MAX];
         size_t size;
         char *data;
+        int err;
 
         scnprintf(path, PATH_MAX, "%s/%s/%s/format",
                   tracing_events_path, sys, name);
 
-        if (filename__read_str(path, &data, &size))
-                return NULL;
+        err = filename__read_str(path, &data, &size);
+        if (err)
+                return ERR_PTR(err);
 
         pevent_parse_format(pevent, &event, data, size, sys);
 
@@ -87,11 +93,14 @@ tp_format(const char *sys, const char *name)
         return event;
 }
 
+/*
+ * Returns pointer with encoded error via <linux/err.h> interface.
+ */
 struct event_format*
 trace_event__tp_format(const char *sys, const char *name)
 {
         if (!tevent_initialized && trace_event__init2())
-                return NULL;
+                return ERR_PTR(-ENOMEM);
 
         return tp_format(sys, name);
 }