[mojo-edk] Prevent watching an invalid FD on early broker pipe closure

[mojo-edk] Prevent watching an invalid FD on early broker pipe closure

If a parent process closes the broker OS pipe to a child before
that child can request a NodeChannel FD from it, the child will
silently ignore this failure and try to bring up a NodeChannel over
an invalid FD.

This means adding FileDescriptorWatchers and ultimately calling
epoll_add on the invalid descriptor, hence the linked bug.

This CL fixes that by terminating child-parent connection early
when the Broker fails to acquire a valid NodeChannel FD.

BUG=620758
R=jam@chromium.org

Committed: https://crrev.com/f0a6234831ce289c4b16327d2418e5ff3c623d54
Cr-Commit-Position: refs/heads/master@{#400523}

[Ken Rockot(use gerrit already), 2016-06-17 20:15:13]

Description was changed from

==========
[mojo-edk] Prevent watching invalid platform handle

This fixes a bug which made it possible for us to try watching
an invalid file descriptor. In particular if a parent process would
close its broker OS pipe to a child before the child could request
its NodeChannel pipe, the child would silently ignore this failure
and attempt to add FileDescriptorWatchers to the (invalid)
NodeChannel PlatformHandle.

BUG=620758
R=jam@chromium.org
==========

to

==========
[mojo-edk] Prevent watching an invalid FD on early pipe closure

If a parent process closes the broker OS pipe to a child before
that child can request a NodeChannel pipe from it, the child will
silently ignore this failure and ultimately add
FileDescriptorWatchers to an invalid FD.

This fixes that bug.

BUG=620758
R=jam@chromium.org
==========

[Ken Rockot(use gerrit already), 2016-06-17 20:16:05]

Description was changed from

==========
[mojo-edk] Prevent watching an invalid FD on early pipe closure

If a parent process closes the broker OS pipe to a child before
that child can request a NodeChannel pipe from it, the child will
silently ignore this failure and ultimately add
FileDescriptorWatchers to an invalid FD.

This fixes that bug.

BUG=620758
R=jam@chromium.org
==========

to

==========
[mojo-edk] Prevent watching an invalid FD on early broker pipe closure

If a parent process closes the broker OS pipe to a child before
that child can request a NodeChannel pipe from it, the child will
silently ignore this failure and ultimately add
FileDescriptorWatchers to an invalid FD.

This fixes that bug.

BUG=620758
R=jam@chromium.org
==========

[Ken Rockot(use gerrit already), 2016-06-17 20:17:40]

Description was changed from

==========
[mojo-edk] Prevent watching an invalid FD on early broker pipe closure

If a parent process closes the broker OS pipe to a child before
that child can request a NodeChannel pipe from it, the child will
silently ignore this failure and ultimately add
FileDescriptorWatchers to an invalid FD.

This fixes that bug.

BUG=620758
R=jam@chromium.org
==========

to

==========
[mojo-edk] Prevent watching an invalid FD on early broker pipe closure

If a parent process closes the broker OS pipe to a child before
that child can request a NodeChannel FD from it, the child will
silently ignore this failure and try to bring up a NodeChannel over
an invalid FD.

This means adding FileDescriptorWatchers and ultimately calling 
epoll_add on the invalid descriptor, hence the linked bug.

This CL fixes that by terminating child-parent connection early
when the Broker fails to acquire a valid NodeChannel FD.

BUG=620758
R=jam@chromium.org
==========

[jam, 2016-06-17 22:09:25]

lgtm

[Ken Rockot(use gerrit already), 2016-06-17 22:09:46]

The CQ bit was checked by rockot@chromium.org

[commit-bot: I haz the power, 2016-06-17 22:10:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2072233005/1

[commit-bot: I haz the power, 2016-06-17 22:15:07]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-17 22:17:43]

Description was changed from

==========
[mojo-edk] Prevent watching an invalid FD on early broker pipe closure

If a parent process closes the broker OS pipe to a child before
that child can request a NodeChannel FD from it, the child will
silently ignore this failure and try to bring up a NodeChannel over
an invalid FD.

This means adding FileDescriptorWatchers and ultimately calling 
epoll_add on the invalid descriptor, hence the linked bug.

This CL fixes that by terminating child-parent connection early
when the Broker fails to acquire a valid NodeChannel FD.

BUG=620758
R=jam@chromium.org
==========

to

==========
[mojo-edk] Prevent watching an invalid FD on early broker pipe closure

If a parent process closes the broker OS pipe to a child before
that child can request a NodeChannel FD from it, the child will
silently ignore this failure and try to bring up a NodeChannel over
an invalid FD.

This means adding FileDescriptorWatchers and ultimately calling
epoll_add on the invalid descriptor, hence the linked bug.

This CL fixes that by terminating child-parent connection early
when the Broker fails to acquire a valid NodeChannel FD.

BUG=620758
R=jam@chromium.org

Committed: https://crrev.com/f0a6234831ce289c4b16327d2418e5ff3c623d54
Cr-Commit-Position: refs/heads/master@{#400523}
==========

[commit-bot: I haz the power, 2016-06-17 22:17:44]

Patchset 1 (id:??) landed as
https://crrev.com/f0a6234831ce289c4b16327d2418e5ff3c623d54
Cr-Commit-Position: refs/heads/master@{#400523}