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Add necessary functions for funmap2

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This commit is contained in:
jD91mZM2
2020-07-23 16:25:22 +02:00
parent ccc577b3a1
commit a811774c58
6 changed files with 182 additions and 29 deletions
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160
src/context/memory.rs
View File

@@ -26,13 +26,6 @@ pub struct UserGrants {
pub inner: BTreeSet<Grant>,
}
impl UserGrants {
/// Returns the grant, if any, which occupies the requested region
pub fn find_conflict(&self, requested: Region) -> Option<&Grant> {
self.inner
.range(..requested)
.next_back()
.filter(|existing| existing.occupies(requested))
}
/// Return a free region with the specified size
pub fn find_free(&self, size: usize) -> Region {
// TODO: Find deallocated regions that fits size
@@ -45,6 +38,28 @@ impl UserGrants {
// Create new region
Region::new(VirtualAddress::new(address), size)
}
/// Returns the grant, if any, which occupies the specified address
pub fn contains(&self, address: VirtualAddress) -> Option<&Grant> {
let byte = Region::byte(address);
self.inner
.range(..byte)
.next_back()
.filter(|existing| existing.occupies(byte))
}
/// Returns an iterator over all grants that occupy some part of the
/// requested region
pub fn conflicts<'a>(&'a self, requested: Region) -> impl Iterator<Item = &'a Grant> + 'a {
let start = self.contains(requested.start_address());
let start_region = start.map(Region::from).unwrap_or(requested);
start
.into_iter()
.chain(
self
.inner
.range(start_region..)
.take_while(move |region| region.occupies(requested))
)
}
}
impl Deref for UserGrants {
type Target = BTreeSet<Grant>;
@@ -77,16 +92,38 @@ impl Region {
}
}
/// Create a new region spanning between the start and end address
/// (exclusive end)
pub fn between(start: VirtualAddress, end: VirtualAddress) -> Self {
Self {
start,
size: end.get() - start.get(),
}
}
/// Return the part of the specified region that intersects with self.
pub fn intersect(&self, other: Self) -> Self {
Self::between(
cmp::max(self.start_address(), other.start_address()),
cmp::min(self.end_address(), other.end_address()),
)
}
/// Get the start address of the region
pub fn start_address(&self) -> VirtualAddress {
self.start
}
/// Set the start address of the region
pub unsafe fn set_start_address(&mut self, start: VirtualAddress) {
pub fn set_start_address(&mut self, start: VirtualAddress) {
self.start = start;
}
/// Get the start address of the next region
/// Get the last address in the region (inclusive end)
pub fn final_address(&self) -> VirtualAddress {
VirtualAddress::new(self.start.get() + self.size - 1)
}
/// Get the start address of the next region (exclusive end)
pub fn end_address(&self) -> VirtualAddress {
VirtualAddress::new(self.start.get() + self.size)
}
@@ -96,8 +133,14 @@ impl Region {
self.size
}
/// Return true if the size of this region is zero. Grants with such a
/// region should never exist.
pub fn is_empty(&self) -> bool {
self.size == 0
}
/// Set the exact size of the region
pub unsafe fn set_size(&mut self, size: usize) {
pub fn set_size(&mut self, size: usize) {
self.size = size;
}
@@ -115,13 +158,13 @@ impl Region {
}
/// Returns true if the address is within the regions's requested range
pub fn contains(&self, other: Self) -> bool {
pub fn collides(&self, other: Self) -> bool {
self.start_address() <= other.start_address() && other.end_address().get() - self.start_address().get() < self.size()
}
/// Returns true if the address is within the regions's actual range (so,
/// rounded up to the page size)
pub fn occupies(&self, other: Self) -> bool {
self.start_address() <= other.start_address() && other.end_address().get() - self.start_address().get() < self.full_size()
self.round().collides(other)
}
}
@@ -132,11 +175,9 @@ impl<'a> From<&'a Grant> for Region {
}
#[derive(Debug)]
#[derive(Debug)]
pub struct Grant {
// TODO: Use region here instead of start/end separately
region: Region,
flags: EntryFlags,
mapped: bool,
owned: bool,
@@ -145,6 +186,12 @@ pub struct Grant {
}
impl Grant {
/// Get a mutable reference to the region. This is unsafe, because a bad
/// region could lead to the wrong addresses being unmapped.
pub unsafe fn region_mut(&mut self) -> &mut Region {
&mut self.region
}
pub fn physmap(from: PhysicalAddress, to: VirtualAddress, size: usize, flags: EntryFlags) -> Grant {
let mut active_table = unsafe { ActivePageTable::new() };
@@ -341,8 +388,8 @@ impl Grant {
let mut flush_all = MapperFlushAll::new();
let start_page = Page::containing_address(self.region.start);
let end_page = Page::containing_address(VirtualAddress::new(self.region.start.get() + self.region.size - 1));
let start_page = Page::containing_address(self.start_address());
let end_page = Page::containing_address(self.final_address());
for page in Page::range_inclusive(start_page, end_page) {
let (result, _frame) = active_table.unmap_return(page, false);
flush_all.consume(result);
@@ -368,8 +415,8 @@ impl Grant {
let mut active_table = unsafe { ActivePageTable::new() };
active_table.with(new_table, temporary_page, |mapper| {
let start_page = Page::containing_address(self.region.start);
let end_page = Page::containing_address(VirtualAddress::new(self.region.start.get() + self.region.size - 1));
let start_page = Page::containing_address(self.start_address());
let end_page = Page::containing_address(self.final_address());
for page in Page::range_inclusive(start_page, end_page) {
let (result, _frame) = mapper.unmap_return(page, false);
// This is not the active table, so the flush can be ignored
@@ -386,6 +433,62 @@ impl Grant {
self.mapped = false;
}
/// Extract out a region into a separate grant. The return value is as
/// follows: (before, new split, after). Before and after may be `None`,
/// which occurs when the split off region is at the start or end of the
/// page respectively.
///
/// # Panics
///
/// Panics if the start or end addresses of the region is not aligned to the
/// page size. To round up the size to the nearest page size, use `.round()`
/// on the region.
pub fn split_out(mut self, region: Region) -> Option<(Option<Grant>, Grant, Option<Grant>)> {
assert_eq!(region.start_address().get() % PAGE_SIZE, 0, "split_out must be called on page-size aligned start address");
assert_eq!(region.size() % PAGE_SIZE, 0, "split_out must be called on page-size aligned end address");
let region = self.intersect(region);
// Regions share no common points
if region.is_empty() {
return None;
}
let before = Region::between(
self.start_address(),
region.start_address(),
);
let after = Region::between(
region.end_address(),
self.end_address(),
);
let before_grant = if before.is_empty() { None } else {
Some(Grant {
region: before,
flags: self.flags,
mapped: self.mapped,
owned: self.owned,
desc_opt: self.desc_opt.clone(),
})
};
let after_grant = if after.is_empty() { None } else {
Some(Grant {
region: after,
flags: self.flags,
mapped: self.mapped,
owned: self.owned,
desc_opt: self.desc_opt.clone(),
})
};
unsafe {
*self.region_mut() = region;
}
Some((before_grant, self, after_grant))
}
}
impl Deref for Grant {
@@ -394,11 +497,6 @@ impl Deref for Grant {
&self.region
}
}
impl DerefMut for Grant {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.region
}
}
impl PartialOrd for Grant {
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
@@ -425,7 +523,7 @@ impl Borrow<Region> for Grant {
impl Drop for Grant {
fn drop(&mut self) {
assert!(!self.mapped);
assert!(!self.mapped, "Grant dropped while still mapped");
}
}
@@ -638,3 +736,15 @@ impl Tls {
);
}
}
#[cfg(tests)]
mod tests {
// TODO: Get these tests working
#[test]
fn region_collides() {
assert!(Region::new(0, 2).collides(Region::new(0, 1)));
assert!(Region::new(0, 2).collides(Region::new(1, 1)));
assert!(!Region::new(0, 2).collides(Region::new(2, 1)));
assert!(!Region::new(0, 2).collides(Region::new(3, 1)));
}
}

2
src/scheme/memory.rs
View File

@@ -58,7 +58,7 @@ impl Scheme for MemoryScheme {
return Err(Error::new(EINVAL));
}
if let Some(grant) = grants.find_conflict(requested) {
if let Some(grant) = grants.contains(requested.start_address()) {
if fixed_noreplace {
println!("grant: conflicts with: {:#x} - {:#x}", grant.start_address().get(), grant.end_address().get());
return Err(Error::new(EEXIST));

2
src/scheme/user.rs
View File

@@ -176,7 +176,7 @@ impl UserInner {
let mut grants = context.grants.lock();
if let Some(region) = grants.find_conflict(Region::byte(VirtualAddress::new(address))).map(Region::from) {
if let Some(region) = grants.contains(VirtualAddress::new(address)).map(Region::from) {
grants.take(&region).unwrap().unmap_inactive(&mut new_table, &mut temporary_page);
return Ok(());
}

2
src/syscall/driver.rs
View File

@@ -131,7 +131,7 @@ pub fn inner_physunmap(virtual_address: usize) -> Result<usize> {
let mut grants = context.grants.lock();
if let Some(region) = grants.find_conflict(Region::byte(VirtualAddress::new(virtual_address))).map(Region::from) {
if let Some(region) = grants.contains(VirtualAddress::new(virtual_address)).map(Region::from) {
grants.take(&region).unwrap().unmap();
return Ok(0);
}

44
src/syscall/fs.rs
View File

@@ -455,7 +455,49 @@ pub fn funmap(virtual_address: usize) -> Result<usize> {
let mut grants = context.grants.lock();
if let Some(region) = grants.find_conflict(Region::byte(VirtualAddress::new(virtual_address))).map(Region::from) {
if let Some(region) = grants.contains(VirtualAddress::new(virtual_address)).map(Region::from) {
let mut grant = grants.take(&region).unwrap();
desc_opt = grant.desc_opt.take();
grant.unmap();
}
}
if let Some(desc) = desc_opt {
let scheme_id = {
let description = desc.description.read();
description.scheme
};
let scheme = {
let schemes = scheme::schemes();
let scheme = schemes.get(scheme_id).ok_or(Error::new(EBADF))?;
scheme.clone()
};
let res = scheme.funmap(virtual_address);
let _ = desc.close();
res
} else {
Err(Error::new(EFAULT))
}
}
}
pub fn funmap2(virtual_address: usize, length: usize) -> Result<usize> {
if virtual_address == 0 {
Ok(0)
} else {
let mut desc_opt = None;
{
let contexts = context::contexts();
let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
let context = context_lock.read();
let mut grants = context.grants.lock();
if let Some(region) = grants.contains(VirtualAddress::new(virtual_address)).map(Region::from) {
let mut grant = grants.take(&region).unwrap();
desc_opt = grant.desc_opt.take();
grant.unmap();

1
src/syscall/mod.rs
View File

@@ -67,6 +67,7 @@ pub fn syscall(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize, bp: u
SYS_FEXEC => fexec(fd, validate_slice(c as *const [usize; 2], d)?, validate_slice(e as *const [usize; 2], f)?),
SYS_FRENAME => frename(fd, validate_slice(c as *const u8, d)?),
SYS_FUNMAP => funmap(b),
SYS_FUNMAP2 => funmap2(b, c),
_ => file_op(a, fd, c, d)
}
}