From 55f1829e77313166957161e7524931cf1ae8926b Mon Sep 17 00:00:00 2001
From: 4lDO2 <4lDO2@protonmail.com>
Date: Sun, 2 Jul 2023 16:23:22 +0200
Subject: [PATCH] Call funmap if applicable.
---
src/context/memory.rs | 59 +++++++++++++++++++++++--------------------
src/scheme/mod.rs | 3 +++
2 files changed, 34 insertions(+), 28 deletions(-)
diff --git a/src/context/memory.rs b/src/context/memory.rs
index 3d35e577..fbff1be1 100644
--- a/src/context/memory.rs
+++ b/src/context/memory.rs
@@ -40,13 +40,28 @@ pub fn map_flags(page_flags: PageFlags<RmmA>) -> MapFlags {
pub struct UnmapResult {
pub file_desc: Option<GrantFileRef>,
+ pub size: usize,
}
-impl Drop for UnmapResult {
- fn drop(&mut self) {
- if let Some(fd) = self.file_desc.take().and_then(|d| Arc::try_unwrap(d.description).ok()) {
- // TODO: Funmap?
- let _ = fd.into_inner().try_close();
+impl UnmapResult {
+ pub fn unmap(mut self) -> Result<()> {
+ let Some(GrantFileRef { base_offset, description }) = self.file_desc.take() else {
+ return Ok(());
+ };
+
+ let (scheme_id, number) = match description.write() {
+ ref desc => (desc.scheme, desc.number),
+ };
+
+ let funmap_result = crate::scheme::schemes()
+ .get(scheme_id).map(Arc::clone).ok_or(Error::new(ENODEV))
+ .and_then(|scheme| scheme.kfunmap(number, base_offset, self.size));
+
+ if let Ok(fd) = Arc::try_unwrap(description) {
+ fd.into_inner().try_close()?;
}
+ funmap_result?;
+
+ Ok(())
}
}
@@ -225,33 +240,17 @@ impl AddrSpace {
}
// Remove irrelevant region
- let UnmapResult { ref mut file_desc } = grant.unmap(&mut this.table.utable, &mut flusher);
+ let unmap_result = grant.unmap(&mut this.table.utable, &mut flusher);
// Notify scheme that holds grant
- if let Some(file_ref) = file_desc.take() {
- notify_files.push((file_ref, intersection));
+ if unmap_result.file_desc.is_some() {
+ notify_files.push(unmap_result);
}
}
drop(self);
- for (file_ref, intersection) in notify_files {
- let scheme_id = { file_ref.description.read().scheme };
-
- let scheme = match crate::scheme::schemes().get(scheme_id) {
- Some(scheme) => Arc::clone(scheme),
- // One could argue that EBADFD could be returned here, but we have already unmapped
- // the memory.
- None => continue,
- };
- // Same here, we don't really care about errors when schemes respond to unmap events.
- // The caller wants the memory to be unmapped, period. When already unmapped, what
- // would we do with error codes anyway?
- // FIXME
- //let _ = scheme.funmap(intersection.base.start_address().data(), intersection.count * PAGE_SIZE);
-
- if let Ok(desc) = Arc::try_unwrap(file_ref.description) {
- let _ = desc.into_inner().try_close();
- }
+ for unmap_result in notify_files {
+ let _ = unmap_result.unmap();
}
Ok(())
@@ -839,6 +838,7 @@ impl Grant {
self.info.flags = flags;
}
+ #[must_use = "will not unmap itself"]
pub fn unmap(mut self, mapper: &mut PageMapper, mut flusher: impl Flusher<RmmA>) -> UnmapResult {
assert!(self.info.mapped);
@@ -873,6 +873,7 @@ impl Grant {
let provider = core::mem::replace(&mut self.info.provider, Provider::PhysBorrowed { base: dangling_frame });
UnmapResult {
+ size: self.info.page_count * PAGE_SIZE,
file_desc: match provider {
Provider::Allocated { cow_file_ref } => cow_file_ref,
Provider::FmapBorrowed { file_ref } => Some(file_ref),
@@ -1028,8 +1029,10 @@ impl Drop for AddrSpace {
// TODO: Optimize away clearing the actual page tables? Since this address space is no
// longer arc-rwlock wrapped, it cannot be referenced `External`ly by borrowing grants,
// so it should suffice to iterate over PageInfos and decrement and maybe deallocate
- // the underlying pages (and send some funmaps possibly).
- grant.unmap(&mut self.table.utable, ());
+ // the underlying pages (and send some funmaps).
+ let res = grant.unmap(&mut self.table.utable, ());
+
+ let _ = res.unmap();
}
}
}
diff --git a/src/scheme/mod.rs b/src/scheme/mod.rs
index bda596f7..a9052e4b 100644
--- a/src/scheme/mod.rs
+++ b/src/scheme/mod.rs
@@ -311,6 +311,9 @@ pub trait KernelScheme: Scheme + Send + Sync + 'static {
fn kfmap(&self, number: usize, addr_space: &Arc<RwLock<AddrSpace>>, map: &crate::syscall::data::Map, consume: bool) -> Result<usize> {
Err(Error::new(EOPNOTSUPP))
}
+ fn kfunmap(&self, number: usize, offset: usize, size: usize) -> Result<()> {
+ Err(Error::new(EOPNOTSUPP))
+ }
fn kopen(&self, path: &str, flags: usize, caller: CallerCtx) -> Result<OpenResult> {
self.open(path, flags, caller.uid, caller.gid).map(OpenResult::SchemeLocal)
--
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