CODEWITHSUNDEEP
clinux-kernel
omer12433
omer12433

Reputation: 309

how to change permissions of heap in kernel space?

I am currently writing a kernel module for Linux and been trying to dynamically allocate a large block of memory and changing its permissions (rwx), but it just won't work.

do_mmap and init_mm seem to be missing (recognized as undefined by the linker). A possible solution might be accessing the kernel's vma but I couldn't find a way to access it.

Is it possible to change permissions of heap in kernel space?

Upvotes: 0

Views: 1026

Answers (1)

Jonathon Reinhart
Jonathon Reinhart

Reputation: 137438

vmalloc_exec is not exported for driver use, so you cannot use it.

However, __vmalloc takes a page protections argument, so it should do what you want:

void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot);

So to allocate executable pages, try this:

void *p = __vmalloc(size, GFP_KERNEL, PAGE_KERNEL_EXEC);

Upvotes: 2

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