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A comment on On self-modifying executables in Rust. Parent comment

Re:On self-modifying executables in Rust by woodruffw on Friday January 28, 2022 @10:40PM (#30123552)
The ptrace APIs also can’t write to read only memory, at least not on modern Linux running on CPUs with modern MMUs. But SMC doesn’t require that, because you can always map (or remap) executable pages as writable.

Executable code is only read-only by default, you can always change that (or just not do it, in the case of a JIT).

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Re:On self-modifying executables in Rust by comex on Saturday January 29, 2022 @01:58AM (#30124390)
> The ptrace APIs also can’t write to read only memory

Sure they can.

https://stackoverflow.com/questions/49442087/how-does-ptrace...

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Re:On self-modifying executables in Rust by woodruffw on Saturday January 29, 2022 @02:33PM (#30129599)
Huh, this is news to me! I always thought that ptrace temporarily changed the page's permissions, rather than bypassing them entirely. My mistake.
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