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Fetching buffer arguments from user space.

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This commit is contained in:
Yifan Wu 2020-12-06 13:56:13 +08:00
parent 3625b7578d
commit 064f1cb5cb
20 changed files with 405 additions and 82 deletions
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37
os/src/mm/page_table.rs
View file

@ -68,7 +68,14 @@ impl PageTable {
frames: vec![frame],
}
}
fn find_pte(&mut self, vpn: VirtPageNum, create: bool) -> Option<&mut PageTableEntry> {
/// Temporarily used to get arguments from user space.
pub fn from_root_ppn(root_ppn: PhysPageNum) -> Self {
Self {
root_ppn,
frames: Vec::new(),
}
}
fn find_pte_create(&mut self, vpn: VirtPageNum) -> Option<&mut PageTableEntry> {
let idxs = vpn.indexes();
let mut ppn = self.root_ppn;
let mut result: Option<&mut PageTableEntry> = None;
@ -79,9 +86,6 @@ impl PageTable {
break;
}
if !pte.is_valid() {
if !create {
return None;
}
let frame = frame_alloc().unwrap();
*pte = PageTableEntry::new(frame.ppn, PTEFlags::V);
self.frames.push(frame);
@ -90,19 +94,36 @@ impl PageTable {
}
result
}
fn find_pte(&self, vpn: VirtPageNum) -> Option<&PageTableEntry> {
let idxs = vpn.indexes();
let mut ppn = self.root_ppn;
let mut result: Option<&PageTableEntry> = None;
for i in 0..3 {
let pte = &ppn.get_pte_array()[idxs[i]];
if i == 2 {
result = Some(pte);
break;
}
if !pte.is_valid() {
return None;
}
ppn = pte.ppn();
}
result
}
pub fn map(&mut self, vpn: VirtPageNum, ppn: PhysPageNum, flags: PTEFlags) {
//println!("mapping {:?} {:?}", vpn, ppn);
let pte = self.find_pte(vpn, true).unwrap();
let pte = self.find_pte_create(vpn).unwrap();
assert!(!pte.is_valid(), "vpn {:?} is mapped before mapping", vpn);
*pte = PageTableEntry::new(ppn, flags | PTEFlags::V);
}
pub fn unmap(&mut self, vpn: VirtPageNum) {
let pte = self.find_pte(vpn, false).unwrap();
let pte = self.find_pte_create(vpn).unwrap();
assert!(pte.is_valid(), "vpn {:?} is invalid before unmapping", vpn);
*pte = PageTableEntry::empty();
}
pub fn translate(&mut self, vpn: VirtPageNum) -> Option<PageTableEntry> {
self.find_pte(vpn, false)
pub fn translate(&self, vpn: VirtPageNum) -> Option<PageTableEntry> {
self.find_pte(vpn)
.map(|pte| {pte.clone()})
}
pub fn token(&self) -> usize {