[tip:perf/core] perf env: Also consider env->arch == NULL as local operation

[tip-bot for Arnaldo Carvalho de Melo]

Commit-ID:  ea75be393677d60dd64b976f8fc91763537b13c7
Gitweb:     https://git.kernel.org/tip/ea75be393677d60dd64b976f8fc91763537b13c7
Author:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Tue, 27 Nov 2018 11:45:49 -0300
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Thu, 29 Nov 2018 20:42:47 -0300

perf env: Also consider env->arch == NULL as local operation

We'll set a new machine field based on env->arch, which for live mode,
like with 'perf top' means we need to use uname() to figure the name of
the arch, fix perf_env__arch() to consider both (env == NULL) and
(env->arch == NULL) as local operation.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Leo Yan <leo.yan@xxxxxxxxxx>
Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # 4.19
Link: https://lkml.kernel.org/n/tip-vcz4ufzdon7cwy8dm2ua53xk@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/env.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index 59f38c7693f8..4c23779e271a 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -166,7 +166,7 @@ const char *perf_env__arch(struct perf_env *env)
 	struct utsname uts;
 	char *arch_name;
 
-	if (!env) { /* Assume local operation */
+	if (!env || !env->arch) { /* Assume local operation */
 		if (uname(&uts) < 0)
 			return NULL;
 		arch_name = uts.machine;