selftests: net: pass bpftrace timeout to cmd()

The bpftrace() helper configures an interval based exit timer but does
not propagate the timeout to the cmd object, which defaults to 5
seconds. Since the default BPFTRACE_TIMEOUT is 10 seconds, cmd.process()
always raises a TimeoutExpired exception before bpftrace has a chance to
exit gracefully.

Pass timeout+5 to cmd() to allow bpftrace to complete gracefully.

Note: this issue is masked by a bug in the way cmd() passes timeout,
this is fixed in the next commit.

Reviewed-by: Nimrod Oren <[email protected]>
Signed-off-by: Gal Pressman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

tools/testing/selftests/net/lib/py/utils.py

@@ -258,8 +258,9 @@ def bpftrace(expr, json=None, ns=None, host=None, timeout=None):
         cmd_arr += ['-f', 'json', '-q']
     if timeout:
         expr += ' interval:s:' + str(timeout) + ' { exit(); }'
+        timeout += 5
     cmd_arr += ['-e', expr]
-    cmd_obj = cmd(cmd_arr, ns=ns, host=host, shell=False)
+    cmd_obj = cmd(cmd_arr, ns=ns, host=host, shell=False, timeout=timeout)
     if json:
         # bpftrace prints objects as lines
         ret = {}