telemetry: Robustify CrOSInterface._GetSessionManagerPid().

telemetry: Robustify CrOSInterface._GetSessionManagerPid().

Allow the session_manager process name to use a relative
path or to not have any arguments, rather than requiring it
to have the prefix "/sbin/session_manager " (note trailing
space).

BUG=377301
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=274225

[Chris Masone, 2014-06-02 00:31:59]

lgtm

lgtm

[Daniel Erat, 2014-06-02 05:07:44]

The CQ bit was checked by derat@chromium.org

[commit-bot: I haz the power, 2014-06-02 05:08:04]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/derat@chromium.org/302163004/1

[commit-bot: I haz the power, 2014-06-02 07:05:52]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  chromium_presubmit on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/chromium_presubmit/bu...)

[commit-bot: I haz the power, 2014-06-02 07:08:31]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-06-02 07:08:32]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/chromium_presubmit/bu...)

[achuithb, 2014-06-02 08:51:20]

lgtm

https://codereview.chromium.org/302163004/diff/1/tools/telemetry/telemetry/co...
File tools/telemetry/telemetry/core/backends/chrome/cros_interface.py (right):

https://codereview.chromium.org/302163004/diff/1/tools/telemetry/telemetry/co...
tools/telemetry/telemetry/core/backends/chrome/cros_interface.py:301: if argv
and os.path.basename(argv[0]) == 'session_manager':
argv should never be empty, right?

[Daniel Erat, 2014-06-02 13:35:09]

The CQ bit was checked by derat@chromium.org

[commit-bot: I haz the power, 2014-06-02 13:35:23]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/derat@chromium.org/302163004/1

[Daniel Erat, 2014-06-02 13:38:23]

https://codereview.chromium.org/302163004/diff/1/tools/telemetry/telemetry/co...
File tools/telemetry/telemetry/core/backends/chrome/cros_interface.py (right):

https://codereview.chromium.org/302163004/diff/1/tools/telemetry/telemetry/co...
tools/telemetry/telemetry/core/backends/chrome/cros_interface.py:301: if argv
and os.path.basename(argv[0]) == 'session_manager':
On 2014/06/02 08:51:20, achuithb wrote:
> argv should never be empty, right?

"".split() returns an empty array. i think that a process can rewrite its argv
to be whatever it wants, so better safe than sorry, i figure.

[commit-bot: I haz the power, 2014-06-02 13:41:57]

Change committed as 274225

[Daniel Erat, 2014-06-02 13:48:17]

https://codereview.chromium.org/302163004/diff/1/tools/telemetry/telemetry/co...
File tools/telemetry/telemetry/core/backends/chrome/cros_interface.py (right):

https://codereview.chromium.org/302163004/diff/1/tools/telemetry/telemetry/co...
tools/telemetry/telemetry/core/backends/chrome/cros_interface.py:301: if argv
and os.path.basename(argv[0]) == 'session_manager':
On 2014/06/02 13:38:24, Daniel Erat wrote:
> On 2014/06/02 08:51:20, achuithb wrote:
> > argv should never be empty, right?
> 
> "".split() returns an empty array. i think that a process can rewrite its argv
> to be whatever it wants, so better safe than sorry, i figure.

(although i'm probably being overly paranoid, since ListProcesses() looks like
it'll fail an assert in this case. it'd probably be safer for this code to read
from /proc instead of running ps; that way it'd also be able to find the real
executable by reading the 'exe' symlink.)