[PATCH] nptl: avoid invalid memory access in pthread_join after fork

[Andreas Schwab]

On Jun 05 2026, Wupeng wrote:

> Calling pthread_join() on threads that no longer exist after fork() is technically undefined behavior. However, in real-world engineering scenarios this is difficult to avoid completely, especially when:
> - pthread_join() is located in shared cleanup/destructor paths
> - parent and child processes share common cleanup logic
> - third-party libraries internally manage threads

Add an atfork handler that cleans up the mess after fork.

-- 
Andreas Schwab, schwab@linux-m68k.org
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