Not everything is detectable at runtime, such as syscall numbers (which is what'... | Hacker News

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		Denvercoder9 on March 31, 2024 \| parent \| context \| favorite \| on: Xz: Can you spot the single character that disable... Not everything is detectable at runtime, such as syscall numbers (which is what's being tested for here).

manwe150 on March 31, 2024 [–]

Runtime syscall number detection is very common in practice, since the kernel returns ENOSYS to enable that exact ability for glibc and other shim libraries

Denvercoder9 on March 31, 2024 | [–]

That's syscall for _availability_ detection, not its number. There's no way to ask the kernel "what's the number of the syscall commonly known as read()".

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