[PATCH 5/7] perf tools: Introduce perf_target__strerror()

From: Namhyung Kim
Date: Mon May 07 2012 - 01:12:33 EST


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.

Suggested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx>
Reviewed-by: David Ahern <dsahern@xxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung.kim@xxxxxxx>
---
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 d26a279796d9..211d28f01eff 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_ERRNO_TARGET__SUCCESS) {
+ perf_target__strerror(&rec->opts.target, err, errbuf, BUFSIZ);
+ ui__warning("%s", errbuf);
+ }
+
+ err = perf_target__parse_uid(&rec->opts.target);
+ if (err != PERF_ERRNO_TARGET__SUCCESS) {
+ 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 59883c8c5817..a2518fc0626a 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 = {
.target = {
.system_wide = true,
@@ -1255,10 +1256,22 @@ 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_ERRNO_TARGET__SUCCESS) {
+ perf_target__strerror(&top.target, status, errbuf, BUFSIZ);
+ ui__warning("%s", errbuf);
+ }
+
+ status = perf_target__parse_uid(&top.target);
+ if (status != PERF_ERRNO_TARGET__SUCCESS) {
+ 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 (perf_evlist__create_maps(top.evlist, &top.target) < 0)
usage_with_options(top_usage, options);
diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index 26817daa2961..efb1fce259a4 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 02a6bedb69a3..1064d5b148ad 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 d4aabdaba42a..6fcd01c440a9 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 */
--
1.7.10.1

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