[PATCH 06/16] perf tools: Introduce perf_target__strerror()

From: Arnaldo Carvalho de Melo
Date: Thu May 10 2012 - 13:17:54 EST


From: Namhyung Kim <namhyung.kim@xxxxxxx>

The perf_target__strerror() sets @buf to a string that describes the
(perf_target-specific) error condition that is passed via @errnum.

This is similar to strerror_r() and does same thing if @errnum has a
standard errno value.

Signed-off-by: Namhyung Kim <namhyung.kim@xxxxxxx>
Suggested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx>
Reviewed-by: David Ahern <dsahern@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/1336367344-28071-6-git-send-email-namhyung.kim@xxxxxxx
[ committer note: No need to use PERF_ERRNO_TARGET__SUCCESS, use shorter idiom ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-record.c | 18 +++++++++++++--
tools/perf/builtin-top.c | 19 +++++++++++++---
tools/perf/util/debug.c | 1 +
tools/perf/util/target.c | 51 +++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/target.h | 3 +++
5 files changed, 87 insertions(+), 5 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index d26a279..c8bf6ea 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -831,6 +831,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
struct perf_evsel *pos;
struct perf_evlist *evsel_list;
struct perf_record *rec = &record;
+ char errbuf[BUFSIZ];

perf_header__set_cmdline(argc, argv);

@@ -884,11 +885,24 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
goto out_symbol_exit;
}

- perf_target__validate(&rec->opts.target);
+ err = perf_target__validate(&rec->opts.target);
+ if (err) {
+ perf_target__strerror(&rec->opts.target, err, errbuf, BUFSIZ);
+ ui__warning("%s", errbuf);
+ }
+
+ err = perf_target__parse_uid(&rec->opts.target);
+ if (err) {
+ int saved_errno = errno;

- if (perf_target__parse_uid(&rec->opts.target) < 0)
+ perf_target__strerror(&rec->opts.target, err, errbuf, BUFSIZ);
+ ui__warning("%s", errbuf);
+
+ err = -saved_errno;
goto out_free_fd;
+ }

+ err = -ENOMEM;
if (perf_evlist__create_maps(evsel_list, &rec->opts.target) < 0)
usage_with_options(record_usage, record_options);

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index c9137ba..7ba0f03 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1150,7 +1150,8 @@ static const char * const top_usage[] = {
int cmd_top(int argc, const char **argv, const char *prefix __used)
{
struct perf_evsel *pos;
- int status = -ENOMEM;
+ int status;
+ char errbuf[BUFSIZ];
struct perf_top top = {
.count_filter = 5,
.delay_secs = 2,
@@ -1252,10 +1253,22 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)

setup_browser(false);

- perf_target__validate(&top.target);
+ status = perf_target__validate(&top.target);
+ if (status) {
+ perf_target__strerror(&top.target, status, errbuf, BUFSIZ);
+ ui__warning("%s", errbuf);
+ }
+
+ status = perf_target__parse_uid(&top.target);
+ if (status) {
+ int saved_errno = errno;

- if (perf_target__parse_uid(&top.target) < 0)
+ perf_target__strerror(&top.target, status, errbuf, BUFSIZ);
+ ui__warning("%s", errbuf);
+
+ status = -saved_errno;
goto out_delete_evlist;
+ }

if (top.target.tid == 0 && top.target.pid == 0 &&
top.target.uid_str == NULL)
diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index 26817da..efb1fce 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -11,6 +11,7 @@
#include "event.h"
#include "debug.h"
#include "util.h"
+#include "target.h"

int verbose;
bool dump_trace = false, quiet = false;
diff --git a/tools/perf/util/target.c b/tools/perf/util/target.c
index 02a6bed..1064d5b 100644
--- a/tools/perf/util/target.c
+++ b/tools/perf/util/target.c
@@ -10,6 +10,7 @@
#include "debug.h"

#include <pwd.h>
+#include <string.h>


enum perf_target_errno perf_target__validate(struct perf_target *target)
@@ -89,3 +90,53 @@ enum perf_target_errno perf_target__parse_uid(struct perf_target *target)
target->uid = result->pw_uid;
return PERF_ERRNO_TARGET__SUCCESS;
}
+
+/*
+ * This must have a same ordering as the enum perf_target_errno.
+ */
+static const char *perf_target__error_str[] = {
+ "PID/TID switch overriding CPU",
+ "PID/TID switch overriding UID",
+ "UID switch overriding CPU",
+ "PID/TID switch overriding SYSTEM",
+ "UID switch overriding SYSTEM",
+ "Invalid User: %s",
+ "Problems obtaining information for user %s",
+};
+
+int perf_target__strerror(struct perf_target *target, int errnum,
+ char *buf, size_t buflen)
+{
+ int idx;
+ const char *msg;
+
+ if (errnum >= 0) {
+ strerror_r(errnum, buf, buflen);
+ return 0;
+ }
+
+ if (errnum < __PERF_ERRNO_TARGET__START ||
+ errnum >= __PERF_ERRNO_TARGET__END)
+ return -1;
+
+ idx = errnum - __PERF_ERRNO_TARGET__START;
+ msg = perf_target__error_str[idx];
+
+ switch (errnum) {
+ case PERF_ERRNO_TARGET__PID_OVERRIDE_CPU
+ ... PERF_ERRNO_TARGET__UID_OVERRIDE_SYSTEM:
+ snprintf(buf, buflen, "%s", msg);
+ break;
+
+ case PERF_ERRNO_TARGET__INVALID_UID:
+ case PERF_ERRNO_TARGET__USER_NOT_FOUND:
+ snprintf(buf, buflen, msg, target->uid_str);
+ break;
+
+ default:
+ /* cannot reach here */
+ break;
+ }
+
+ return 0;
+}
diff --git a/tools/perf/util/target.h b/tools/perf/util/target.h
index d4aabda..6fcd01c 100644
--- a/tools/perf/util/target.h
+++ b/tools/perf/util/target.h
@@ -43,4 +43,7 @@ enum perf_target_errno {
enum perf_target_errno perf_target__validate(struct perf_target *target);
enum perf_target_errno perf_target__parse_uid(struct perf_target *target);

+int perf_target__strerror(struct perf_target *target, int errnum, char *buf,
+ size_t buflen);
+
#endif /* _PERF_TARGET_H */
--
1.7.9.2.358.g22243

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