Bug 11315 - Potential DeadLock in processes.c when fork failed
Summary: Potential DeadLock in processes.c when fork failed
Alias: None
Product: Runtime
Classification: Mono
Component: io-layer ()
Version: unspecified
Hardware: PC Linux
: --- normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2013-03-21 06:16 UTC by gilles.grospellier
Modified: 2013-03-21 21:23 UTC (History)
3 users (show)

Is this bug a regression?: ---
Last known good build:

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Description gilles.grospellier 2013-03-21 06:16:53 UTC
In mono version 3.0.6, in file io-layer/processes.c, in function CreateProcess, the fork() function is called line 965.
If the fork failed,  _wapi_handle_unref() is called and deadlock because it try to lock shared handle (via _wapi_handle_lock_shared_handles) and the lock is already taken before the fork call (line 961), which result in a deadlock. One solution is to release the lock before calling _wapi_handle_unref() and take it again after (because it is released during cleanup).

Also, when fork failed you suppose the error is ENOMEM but it may also be EAGAIN when too many process are launched at the same time.
Comment 1 Zoltan Varga 2013-03-21 21:23:28 UTC
Fixed in master/mono-2-10 branches.