[release/9.0-staging] Don't use vfork on android #118331
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When we start the child process, we clear all signal handlers. This operations ends up clearing the signal handlers also for the parent process. Revert to just using fork for simplicity.
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Tagging subscribers to this area: @dotnet/area-system-diagnostics-process |
This was referenced Aug 4, 2025
BrzVlad
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/ba-g Too generic of a timeout |
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Backport of #118085 to release/9.0-staging
When we start the child process, we clear all signal handlers. When using vfork, on Android, this operation ends up clearing the signal handlers also for the parent process. Revert to just using fork for simplicity.
vfork usage was added back in dotnet/corefx#33289, seems like there were some potential concerns then.
Legacy Xamarin was using fork.
Fixes #97209.
Customer Impact
Using
System.Diagnostics.Process.Startbreaks the signal handlers of the runtime. This api can also be used as part of some BCL functionality, for exampleSystem.Net.NetworkingInformation.Ping. One of the side effects of this is that NRE is no longer thrown when dereferencing a null pointer. This essentially means that the runtime is completely broken after usingProcess.Start. This impacts users migrating from legacy Xamarin to MAUI.Regression
Regression compared to legacy Xamarin. It was always broken on MAUI however.
Testing
Tested locally with sample application.
Risk
Low. This commit simply reverts to using
forkinstead ofvforkon android. This was the default on Xamarin. Whileforkis less optimized (it might make the process start a few milliseconds slower and use more memory), it is not used heavily in MAUI. This also won't impact users, because customers usingProcess.Startbefore would run into other completely breaking issues anyway.