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From: Godmar Back <godmar@gmail.com>
Date: Sun, 14 Feb 2021 17:04:28 -0500
Message-ID: <CAB4+JYJ8HE4eMUU3drbXRQ-s_saC1MnB0+p+e+d91Dku5Am-ZQ@mail.gmail.com>
Subject: Re: (stat(...) == -1 || faccessat(...) == -1) && errno == EINTR ?!??
To: Tobias Bading <tbading@web.de>
Cc: William Tambe via Libc-help <libc-help@sourceware.org>
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I don't know if this qualifies as "breaking userland" or "this has
never worked."

You could use systemtap to patch the kernel to see if you can trap the
path where they're returning `EINTR`.
I recently came across a blog post:
https://engineering.skroutz.gr/blog/uncovering-a-24-year-old-bug-in-the-linux-kernel/
where some people did that and found a bug in the TCP code. Very
impressive.