Re: [PATCH 3/4] arm64: separate code and data virtual memory allocation

Christophe Leroy
2024-02-21T07:20:13Z

Le 20/02/2024 à 21:32, Maxwell Bland a écrit :
> [Vous ne recevez pas souvent de courriers de mbland@motorola.com. Découvrez pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ]
>
> Current BPF and kprobe instruction allocation interfaces do not match
> the base kernel and intermingle code and data pages within the same
> sections. In the case of BPF, this appears to be a result of code
> duplication between the kernel's JIT compiler and arm64's JIT. However,
> This is no longer necessary given the possibility of overriding vmalloc
> wrapper functions.

Why do you need to override vmalloc wrapper functions for that ?

See powerpc, for kprobes, alloc_insn_page() uses module_alloc().
On powerpc, the approach is that vmalloc() provides non-exec memory
while module_alloc() provides executable memory.

Christophe