[Bug 1087720] New: signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

Bug ID: 1087720
           Summary: signal 27 (SIGPROF) not passed to container using
                    --sig-proxy
           Product: Fedora
           Version: 20
         Component: docker-io
          Assignee: [e-mail]
          Reporter: [e-mail]
        QA Contact: [e-mail]
                CC: [e-mail], [e-mail],
                    [e-mail], [e-mail],
                    [e-mail], [e-mail],
                    [e-mail]

Description of problem:
When I send signal 27 to the docker process, which is running with
--sig-proxy=true, it's not forwarded. Other signals are...

Version-Release number of selected component (if applicable):
docker-io-0.9.1-1.fc21.x86_64

How reproducible:
always

Steps to Reproduce:
1. /usr/bin/docker -D run --tty=false --rm -i --name test_eoly
localhost:5000/ldoktor/fedora:latest bash -c 'for NUM in `seq 1 64`; do trap
"echo Received $NUM, ignoring..." $NUM; done; while :; do sleep 1; done'
2. ps ax |grep docker
3. kill -27 $PID

Actual results:
nothing

Expected results:
Received 27, ignoring...

Additional info:
When you send any other signal (apart from 19 or 9) it works fine.

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

--- Comment #1 from Lukas Doktor  ---
The signal 17 is also ignored.

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

--- Comment #2 from Lukas Doktor  ---
The same bug is in upstream Docker version 0.10.0, build dc9c28f/0.10.0

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

Lukas Doktor  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Blocks|                            |1096276

Referenced Bugs:

https://bugzilla.redhat.com/show_bug.cgi?id=1096276
[Bug 1096276] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

Daniel Walsh  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[e-mail]

--- Comment #3 from Daniel Walsh  ---
We are keeping all of the versions of docker insync, please only report these
bugs once.

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

Daniel Walsh  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|[e-mail]             |[e-mail]

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

Daniel Walsh  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|[e-mail]           |[e-mail]

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

--- Comment #4 from Matthew Heon  ---
With upstream Docker, signal 27 works. Signal 17, however, is still broken.

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

--- Comment #5 from Matthew Heon  ---
After further testing, I've determined that all signals are sent correctly
except 17 and 19. I'm looking into a fix for this.

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

--- Comment #6 from Matthew Heon  ---
Signal 17, SIGCHILD, is deliberately not forwarded - upstream commit
https://github.com/dotcloud/docker/commit/440422a96346072a0a9016c4db78ff7599....

Signal 19 might actually be a Golang bug - I've constructed a small test
program in Go which also fails to catch this. Looking into this further.

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

Daniel Walsh  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED

--- Comment #7 from Daniel Walsh  ---
I think we should just document, ignoring sigchld makes sense.

We should document in the man page that signal 17 should be ignored, and signal
19 is a bug in golang.

Just fix the man page.

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

--- Comment #8 from Matthew Heon  ---
PR out: https://github.com/dotcloud/docker/pull/6544

It appears that Signal 19 is actually forwarded, also. SIGSTOP cannot be
caught, so it was actually preventing my script from printing out that it was
received. So it's only Signal 17 that's not forwarded.

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

--- Comment #10 from Matthew Heon  ---
After further testing, I've managed to reproduce being unable to send signals
19, 18, and 27 to the container via --sig-proxy.

This seems to be a Golang issue. I implemented a trivial signal-catching test
program in Go and tested it with signals 1-31, and obtained identical results
to Docker aside from Signal 17 (discarded on Docker, caught by my test
program).

A brief summary of signals Docker does not play well with:
- Signal 17, SIGCHLD, deliberately caught and discarded. Makes no sense to pass
this into a container.
- Signal 18, SIGCONT, seems to be Golang issue
- Signal 19, SIGSTOP, unmaskable signal - cannot be caught
- Signal 27, SIGPROF, seems to be Golang issue

Worth noting that the "docker kill" command should be able to send any of these
without issue. If we have any general docs for Docker, we may want to recommend
avoiding proxying signals in favor of docker kill whenever possible.

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

--- Comment #11 from Matthew Heon  ---
Appears to be an issue with Golang proper
(https://code.google.com/p/go/issues/detail?id=4391&q=signal&colspec=...)

Unknown when a fix will be released - there hasn't been any movement on the bug
since February.

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

John Skeoch  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|[e-mail]            |[e-mail]

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

Daniel Walsh  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|[e-mail]          |[e-mail]

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

Daniel Walsh  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|[e-mail]           |[e-mail]

[Bug 1087720] signal 27 (SIGPROF) not passed to container using --sig-proxy

[Red Hat Bugzilla]

https://bugzilla.redhat.com/show_bug.cgi?id=1087720

Daniel Walsh  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |CLOSED
         Resolution|---                         |CANTFIX
        Last Closed|                            |2015-04-15 08:16:44

--- Comment #13 from Daniel Walsh  ---
Bug is in golang, have to wait until golang is fixed handling of signals.