Kernel/syscalls/native/munmap.cpp
2024-01-19 06:47:42 +02:00

61 lines
1.5 KiB
C++

/*
This file is part of Fennix Kernel.
Fennix Kernel is free software: you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation, either version 3 of
the License, or (at your option) any later version.
Fennix Kernel is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
*/
#include <syscalls.hpp>
#include <memory.hpp>
#include <lock.hpp>
#include <exec.hpp>
#include <errno.h>
#include <debug.h>
#include "../../syscalls.h"
#include "../../kernel.h"
using Tasking::PCB;
using namespace Memory;
/* https://pubs.opengroup.org/onlinepubs/009604499/functions/munmap.html */
int sys_munmap(SysFrm *,
void *addr, size_t len)
{
if (uintptr_t(addr) % PAGE_SIZE)
return -EINVAL;
if (len == 0)
return -EINVAL;
PCB *pcb = thisProcess;
VirtualMemoryArea *vma = pcb->vma;
Virtual vmm = Virtual(pcb->PageTable);
for (uintptr_t i = uintptr_t(addr);
i < uintptr_t(addr) + len;
i += PAGE_SIZE)
{
if (likely(!vmm.Check((void *)i, G)))
vmm.Remap((void *)i, (void *)i, P | RW);
else
warn("%p is a global page", (void *)i);
}
/* TODO: Check if the page is allocated
and not only mapped */
vma->FreePages((void *)addr, TO_PAGES(len) + 1);
return 0;
}