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[17.06] backport: Avoid race when opening exec fifo #4
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When starting a container with `runc start` or `runc run`, the stub process (runc[2:INIT]) opens a fifo for writing. Its parent runc process will open the same fifo for reading. In this way, they synchronize. If the stub process exits at the wrong time, the parent runc process will block forever. This can happen when racing 2 runc operations against each other: `runc run/start`, and `runc delete`. It could also happen for other reasons, e.g. the kernel's OOM killer may select the stub process. This commit resolves this race by racing the opening of the exec fifo from the runc parent process against the stub process exiting. If the stub process exits before we open the fifo, we return an error. Another solution is to wait on the stub process. However, it seems it would require more refactoring to avoid calling wait multiple times on the same process, which is an error. Signed-off-by: Craig Furman <cfurman@pivotal.io> (cherry picked from commit 8d3e6c9) Signed-off-by: Andrew Hsu <andrewhsu@docker.com>
Signed-off-by: Craig Furman <cfurman@pivotal.io> (cherry picked from commit 5c0af14) Signed-off-by: Andrew Hsu <andrewhsu@docker.com>
tiborvass
changed the title
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LGTM |
Signed-off-by: Tibor Vass <tibor@docker.com>
Signed-off-by: Andrew Hsu <andrewhsu@docker.com> Signed-off-by: Tibor Vass <tibor@docker.com>
Signed-off-by: Tibor Vass <tibor@docker.com>
CRIU needs to load a few modules to checkpoint/resume containers. opencontainers#1745 Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
And use it only in local tooling that is forwarding the pseudoterminal master. That way runC no longer has an opinion on the onlcr setting for folks who are creating a terminal and detaching. They'll use --console-socket and can setup the pseudoterminal however they like without runC having an opinion. With this commit, the only cases where runC still has applies SaneTerminal is when *it* is the process consuming the master descriptor. Signed-off-by: W. Trevor King <wking@tremily.us> (cherry picked from commit 830c0d7) Signed-off-by: Tibor Vass <tibor@docker.com>
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This PR is not desired anymore. |
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backport:
with cherry-pick:
no conflicts