[PATCH v5 19/23] perf trace: Avoid global perf_env with evsel__env

From: Ian Rogers
Date: Sat Jun 28 2025 - 00:54:51 EST


There is no session in perf trace unless in replay mode, so in host
mode no session can be associated with the evlist. If the evsel__env
call fails resort to the host_env that's part of the trace. Remove
errno_to_name as it becomes a called once 1-line function once the
argument is turned into a perf_env, just call perf_env__arch_strerrno
directly.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/builtin-trace.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index d52f21afdeb1..da94cd28c8dc 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -2904,13 +2904,6 @@ static int trace__fprintf_callchain(struct trace *trace, struct perf_sample *sam
return sample__fprintf_callchain(sample, 38, print_opts, get_tls_callchain_cursor(), symbol_conf.bt_stop_list, trace->output);
}

-static const char *errno_to_name(struct evsel *evsel, int err)
-{
- struct perf_env *env = evsel__env(evsel);
-
- return perf_env__arch_strerrno(env, err);
-}
-
static int trace__sys_exit(struct trace *trace, struct evsel *evsel,
union perf_event *event __maybe_unused,
struct perf_sample *sample)
@@ -2996,8 +2989,9 @@ static int trace__sys_exit(struct trace *trace, struct evsel *evsel,
} else if (ret < 0) {
errno_print: {
char bf[STRERR_BUFSIZE];
- const char *emsg = str_error_r(-ret, bf, sizeof(bf)),
- *e = errno_to_name(evsel, -ret);
+ struct perf_env *env = evsel__env(evsel) ?: &trace->host_env;
+ const char *emsg = str_error_r(-ret, bf, sizeof(bf));
+ const char *e = perf_env__arch_strerrno(env, err);

fprintf(trace->output, "-1 %s (%s)", e, emsg);
}
--
2.50.0.727.gbf7dc18ff4-goog