Input/output error on PTRACE_PEEKDATA on recent kernels

[remram44]

In some situations, PTRACE_PEEKDATA returns Input/output error (errno=EIO).

This should be investigated and defended against.

[remram44]

Found this thread: https://lkml.iu.edu/hypermail/linux/kernel/1712.2/04964.html

Initial testing shows that this is a problem on Linux 6.2.0-26-generic and 5.4.0-110-generic

[remram44]

Might be an issue of missing CAP_SYS_PTRACE in containers, have to re-test.

[remram44]

This doesn't happen if you're root and have CAP_SYS_PTRACE (which is not the default in containers). I see it happening on GitHub Actions, have to investigate.