[PATCH] perf-script: assume native_arch for pipe mode

[Song Liu]

In pipe mode, session->header.env.arch is not populated until the events
are processed. Therefore, the following command crashes:

   perf record -o - | perf script

(gdb) bt

It fails when we try to compare env.arch against uts.machine:

        if (!strcmp(uts.machine, session->header.env.arch) ||
            (!strcmp(uts.machine, "x86_64") &&
             !strcmp(session->header.env.arch, "i386")))
                native_arch = true;

In pipe mode, it is tricky to find env.arch at this stage. To keep it
simple, let's just assume native_arch is always true for pipe mode.

Cc: sta...@vger.kernel.org #v5.1+
Fixes: 3ab481a1cfe1 ("perf script: Support insn output for normal samples")
Reported-by: David Carrillo Cisneros <davi...@fb.com>
Signed-off-by: Song Liu <songliubrav...@fb.com>
---
 tools/perf/builtin-script.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 61f00055476a..3355af25e7d0 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -3733,7 +3733,8 @@ int cmd_script(int argc, const char **argv)
                goto out_delete;
 
        uname(&uts);
-       if (!strcmp(uts.machine, session->header.env.arch) ||
+       if (data.is_pipe ||  /* assume pipe_mode indicates native_arch */
+           !strcmp(uts.machine, session->header.env.arch) ||
            (!strcmp(uts.machine, "x86_64") &&
             !strcmp(session->header.env.arch, "i386")))
                native_arch = true;
-- 
2.17.1