[PATCH 4/5] perf trace: Obtain errno values by using arch_errno_to_name()

Hendrik Brueckner
2018-01-16T09:46:30Z

Replace the errno_to_name() from the audit-libs with the newly
introduced arch_errno_to_name() function.

With this change:

1. With replacing errno_to_name() from audit-libs, perf trace
does no longer require audit-lib interfaces.

2. In addition to 1, the audit-libs dependency can be removed
for architectures that support syscall tables in perf.
This is achieved in a follow-up commit.

3. With the architecture specific errno number/name mapping,
perf trace reports can work across architectures.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
---
tools/perf/builtin-trace.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 0362974..f7a57b6 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -21,6 +21,7 @@
#include "builtin.h"
#include "util/color.h"
#include "util/debug.h"
+#include "util/env.h"
#include "util/event.h"
#include "util/evlist.h"
#include <subcmd/exec-cmd.h>
@@ -42,17 +43,16 @@
#include "string2.h"
#include "syscalltbl.h"
#include "rb_resort.h"
+#include "util/errno-names.h"

#include <errno.h>
#include <inttypes.h>
-#include <libaudit.h> /* FIXME: Still needed for audit_errno_to_name */
#include <poll.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <linux/err.h>
#include <linux/filter.h>
-#include <linux/audit.h>
#include <linux/kernel.h>
#include <linux/random.h>
#include <linux/stringify.h>
@@ -1660,6 +1660,14 @@ static int trace__fprintf_callchain(struct trace *trace, struct perf_sample *sam
return sample__fprintf_callchain(sample, 38, print_opts, &callchain_cursor, trace->output);
}

+static const char *errno_to_name(struct perf_evsel *evsel, int err)
+{
+ struct perf_env *env = perf_evsel__env(evsel);
+ const char *arch_name = perf_env__arch(env);
+
+ return arch_errno_to_name(arch_name, err);
+}
+
static int trace__sys_exit(struct trace *trace, struct perf_evsel *evsel,
union perf_event *event __maybe_unused,
struct perf_sample *sample)
@@ -1730,7 +1738,7 @@ static int trace__sys_exit(struct trace *trace, struct perf_evsel *evsel,
errno_print: {
char bf[STRERR_BUFSIZE];
const char *emsg = str_error_r(-ret, bf, sizeof(bf)),
- *e = audit_errno_to_name(-ret);
+ *e = errno_to_name(evsel, -ret);

fprintf(trace->output, ") = -1 %s %s", e, emsg);
}
--
1.8.3.1