mprotect.c

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#include "hal/cpu/core.h"
#include "hal/cpu/paging.h"
#include "libk/serial.h"
#include "memory/memory_utils.h"
#include "memory/vm_manager.h"
#include "sys/err_no.h"
#include <sys/syscall.h>
 
int syscall_mprotect(void* addr, size_t len, int prot) {
    (void)addr;
    (void)len;
    (void)prot;
 
    serial2_printf("mprotect: addr 0x%x, len 0x%x, prot %d\n", addr, len,
                   prot);
    auto thr = get_current_core_data()->active_thread;
    auto procc = thr->process;
 
    if (!thr || !procc) {
        return -1;
    }
 
    uint64_t mmap_flags = PAGE_USER;
    if (!prot) {
        mmap_flags = 0;
    } else {
        if (prot & PROT_READ)
            mmap_flags |= PAGE_PRESENT;
        if (prot & PROT_WRITE)
            mmap_flags |= PAGE_WRITABLE;
        if (!(prot & PROT_EXEC))
            mmap_flags |= PAGE_NO_EXECUTE;
 
        if (prot & (PROT_READ | PROT_WRITE | PROT_EXEC))
            mmap_flags |= PAGE_PRESENT;
    }
 
    auto addr_4kb = ALIGN_DOWN((uintptr_t)addr, 0x1000);
    serial2_printf("mrpotect: base aligned 0x%x\n", addr_4kb);
 
    auto mm = vma_find(procc->vm_page, (uintptr_t)addr);
    if (!mm) {
        return -1;
    }
 
    auto len_4kb = ALIGN_UP(len, 0x1000) / 0x1000;
    vxMultipleMmap(thr->page, (uint64_t)addr, (uint64_t)mm->phys_address,
                   len_4kb, mmap_flags);
 
    return 0;
}