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Pin PhysBorrowed head/tail UserScheme grants too.

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This commit is contained in:
4lDO2
2023-07-04 12:29:52 +02:00
parent 329d60848c
commit ba62c0606e
3 changed files with 26 additions and 17 deletions
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src/context/memory.rs
+17 -14
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@@ -98,12 +98,16 @@ impl AddrSpace {
for (grant_base, grant_info) in self.grants.iter() {
let new_grant = match grant_info.provider {
Provider::PhysBorrowed { base } => Grant::physmap(
// No, your temporary UserScheme mappings will not be kept across forks.
Provider::External { is_pinned_userscheme_borrow: true, .. } | Provider::PhysBorrowed { is_pinned_userscheme_borrow: true, .. } => continue,
Provider::PhysBorrowed { base, is_pinned_userscheme_borrow: false } => Grant::physmap(
base.clone(),
PageSpan::new(grant_base, grant_info.page_count),
grant_info.flags,
new_mapper,
(),
false, // is_pinned_userscheme_borrow
)?,
Provider::Allocated { ref cow_file_ref } => Grant::cow(
Arc::clone(&self_arc),
@@ -118,9 +122,6 @@ impl AddrSpace {
cow_file_ref.clone(),
)?,
// No, your temporary UserScheme mappings will not be kept across forks.
Provider::External { is_pinned_userscheme_borrow: true, .. } => continue,
// MAP_SHARED grants are retained by reference, across address space clones (across
// forks on monolithic kernels).
Provider::External { ref address_space, src_base, .. } => Grant::borrow_grant(
@@ -611,7 +612,9 @@ pub enum Provider {
/// The grant is not owned, but borrowed from physical memory frames that do not belong to the
/// frame allocator.
PhysBorrowed { base: Frame },
// TODO: Stop using PhysBorrowed for head/tail pages when doing scheme calls! Force userspace
// to provide it, perhaps from relibc?
PhysBorrowed { base: Frame, is_pinned_userscheme_borrow: bool },
/// The memory is borrowed directly from another address space.
External { address_space: Arc<RwLock<AddrSpace>>, src_base: Page, is_pinned_userscheme_borrow: bool },
@@ -641,14 +644,14 @@ static THE_ZEROED_FRAME: Once<Frame> = Once::new();
impl Grant {
// TODO: PageCount newtype, to avoid confusion between bytes and pages?
pub fn physmap(phys: Frame, span: PageSpan, flags: PageFlags<RmmA>, mapper: &mut PageMapper, mut flusher: impl Flusher<RmmA>) -> Result<Grant> {
pub fn physmap(phys: Frame, span: PageSpan, flags: PageFlags<RmmA>, mapper: &mut PageMapper, mut flusher: impl Flusher<RmmA>, is_pinned_userscheme_borrow: bool) -> Result<Grant> {
Ok(Grant {
base: span.base,
info: GrantInfo {
page_count: span.count,
flags,
mapped: true,
provider: Provider::PhysBorrowed { base: phys },
provider: Provider::PhysBorrowed { base: phys, is_pinned_userscheme_borrow },
},
})
}
@@ -924,7 +927,7 @@ impl Grant {
// Dummy value, won't be read.
let dangling_frame = Frame::containing_address(PhysicalAddress::new(PAGE_SIZE));
let provider = core::mem::replace(&mut self.info.provider, Provider::PhysBorrowed { base: dangling_frame });
let provider = core::mem::replace(&mut self.info.provider, Provider::PhysBorrowed { base: dangling_frame, is_pinned_userscheme_borrow: false });
UnmapResult {
size: self.info.page_count * PAGE_SIZE,
@@ -970,7 +973,7 @@ impl Grant {
is_pinned_userscheme_borrow: false,
},
Provider::Allocated { ref cow_file_ref } => Provider::Allocated { cow_file_ref: cow_file_ref.clone() },
Provider::PhysBorrowed { ref base } => Provider::PhysBorrowed { base: base.clone() },
Provider::PhysBorrowed { base, .. } => Provider::PhysBorrowed { base: base.clone(), is_pinned_userscheme_borrow: false },
Provider::FmapBorrowed { ref file_ref } => Provider::FmapBorrowed { file_ref: file_ref.clone() }
}
},
@@ -979,7 +982,7 @@ impl Grant {
let middle_page_offset = before_grant.as_ref().map_or(0, |g| g.info.page_count);
match self.info.provider {
Provider::PhysBorrowed { ref mut base } => *base = base.next_by(middle_page_offset),
Provider::PhysBorrowed { ref mut base, .. } => *base = base.next_by(middle_page_offset),
// TODO: Adjust cow_file_ref offset
Provider::FmapBorrowed { ref mut file_ref } | Provider::Allocated { cow_file_ref: Some(ref mut file_ref) } => file_ref.base_offset += middle_page_offset * PAGE_SIZE,
Provider::Allocated { cow_file_ref: None } | Provider::External { .. } => (),
@@ -1005,7 +1008,7 @@ impl Grant {
is_pinned_userscheme_borrow: false,
},
Provider::PhysBorrowed { base } => Provider::PhysBorrowed { base: base.next_by(this_span.count) },
Provider::PhysBorrowed { base, .. } => Provider::PhysBorrowed { base: base.next_by(this_span.count), is_pinned_userscheme_borrow: false },
Provider::FmapBorrowed { ref file_ref } => Provider::FmapBorrowed { file_ref: GrantFileRef {
base_offset: file_ref.base_offset + this_span.count * PAGE_SIZE,
description: Arc::clone(&file_ref.description),
@@ -1022,10 +1025,10 @@ impl Grant {
}
impl GrantInfo {
pub fn is_pinned(&self) -> bool {
matches!(self.provider, Provider::External { is_pinned_userscheme_borrow: true, .. })
matches!(self.provider, Provider::External { is_pinned_userscheme_borrow: true, .. } | Provider::PhysBorrowed { is_pinned_userscheme_borrow: true, .. })
}
pub fn unpin(&mut self) {
if let Provider::External { ref mut is_pinned_userscheme_borrow, .. } = self.provider {
if let Provider::External { ref mut is_pinned_userscheme_borrow, .. } | Provider::PhysBorrowed { ref mut is_pinned_userscheme_borrow, .. } = self.provider {
*is_pinned_userscheme_borrow = false;
}
}
@@ -1317,7 +1320,7 @@ fn correct_inner(addr_space_lock: Arc<RwLock<AddrSpace>>, faulting_page: Page, a
}
}
}
Provider::PhysBorrowed { base } => {
Provider::PhysBorrowed { base, .. } => {
base.next_by(pages_from_grant_start)
}
Provider::External { address_space: ref foreign_address_space, src_base, .. } => {