diff options
Diffstat (limited to 'pkg/sentry/memmap/memmap.go')
| -rw-r--r-- | pkg/sentry/memmap/memmap.go | 59 |
1 files changed, 36 insertions, 23 deletions
diff --git a/pkg/sentry/memmap/memmap.go b/pkg/sentry/memmap/memmap.go index 65d83096f..a44fa2b95 100644 --- a/pkg/sentry/memmap/memmap.go +++ b/pkg/sentry/memmap/memmap.go @@ -28,9 +28,9 @@ import ( // // See mm/mm.go for Mappable's place in the lock order. // -// Preconditions: For all Mappable methods, usermem.AddrRanges and -// MappableRanges must be non-empty (Length() != 0), and usermem.Addrs and -// Mappable offsets must be page-aligned. +// All Mappable methods have the following preconditions: +// * usermem.AddrRanges and MappableRanges must be non-empty (Length() != 0). +// * usermem.Addrs and Mappable offsets must be page-aligned. type Mappable interface { // AddMapping notifies the Mappable of a mapping from addresses ar in ms to // offsets [offset, offset+ar.Length()) in this Mappable. @@ -48,8 +48,10 @@ type Mappable interface { // addresses ar in ms to offsets [offset, offset+ar.Length()) in this // Mappable. // - // Preconditions: offset+ar.Length() does not overflow. The removed mapping - // must exist. writable must match the corresponding call to AddMapping. + // Preconditions: + // * offset+ar.Length() does not overflow. + // * The removed mapping must exist. writable must match the + // corresponding call to AddMapping. RemoveMapping(ctx context.Context, ms MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) // CopyMapping notifies the Mappable of an attempt to copy a mapping in ms @@ -60,9 +62,10 @@ type Mappable interface { // CopyMapping is only called when a mapping is copied within a given // MappingSpace; it is analogous to Linux's vm_operations_struct::mremap. // - // Preconditions: offset+srcAR.Length() and offset+dstAR.Length() do not - // overflow. The mapping at srcAR must exist. writable must match the - // corresponding call to AddMapping. + // Preconditions: + // * offset+srcAR.Length() and offset+dstAR.Length() do not overflow. + // * The mapping at srcAR must exist. writable must match the + // corresponding call to AddMapping. CopyMapping(ctx context.Context, ms MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64, writable bool) error // Translate returns the Mappable's current mappings for at least the range @@ -77,11 +80,14 @@ type Mappable interface { // reference is held on all pages in a File that may be the result // of a valid Translation. // - // Preconditions: required.Length() > 0. optional.IsSupersetOf(required). - // required and optional must be page-aligned. The caller must have - // established a mapping for all of the queried offsets via a previous call - // to AddMapping. The caller is responsible for ensuring that calls to - // Translate synchronize with invalidation. + // Preconditions: + // * required.Length() > 0. + // * optional.IsSupersetOf(required). + // * required and optional must be page-aligned. + // * The caller must have established a mapping for all of the queried + // offsets via a previous call to AddMapping. + // * The caller is responsible for ensuring that calls to Translate + // synchronize with invalidation. // // Postconditions: See CheckTranslateResult. Translate(ctx context.Context, required, optional MappableRange, at usermem.AccessType) ([]Translation, error) @@ -118,7 +124,7 @@ func (t Translation) FileRange() FileRange { // CheckTranslateResult returns an error if (ts, terr) does not satisfy all // postconditions for Mappable.Translate(required, optional, at). // -// Preconditions: As for Mappable.Translate. +// Preconditions: Same as Mappable.Translate. func CheckTranslateResult(required, optional MappableRange, at usermem.AccessType, ts []Translation, terr error) error { // Verify that the inputs to Mappable.Translate were valid. if !required.WellFormed() || required.Length() <= 0 { @@ -214,7 +220,9 @@ type MappingSpace interface { // Invalidate must not take any locks preceding mm.MemoryManager.activeMu // in the lock order. // - // Preconditions: ar.Length() != 0. ar must be page-aligned. + // Preconditions: + // * ar.Length() != 0. + // * ar must be page-aligned. Invalidate(ar usermem.AddrRange, opts InvalidateOpts) } @@ -375,16 +383,20 @@ type File interface { // IncRef increments the reference count on all pages in fr. // - // Preconditions: fr.Start and fr.End must be page-aligned. fr.Length() > - // 0. At least one reference must be held on all pages in fr. (The File - // interface does not provide a way to acquire an initial reference; - // implementors may define mechanisms for doing so.) + // Preconditions: + // * fr.Start and fr.End must be page-aligned. + // * fr.Length() > 0. + // * At least one reference must be held on all pages in fr. (The File + // interface does not provide a way to acquire an initial reference; + // implementors may define mechanisms for doing so.) IncRef(fr FileRange) // DecRef decrements the reference count on all pages in fr. // - // Preconditions: fr.Start and fr.End must be page-aligned. fr.Length() > - // 0. At least one reference must be held on all pages in fr. + // Preconditions: + // * fr.Start and fr.End must be page-aligned. + // * fr.Length() > 0. + // * At least one reference must be held on all pages in fr. DecRef(fr FileRange) // MapInternal returns a mapping of the given file offsets in the invoking @@ -392,8 +404,9 @@ type File interface { // // Note that fr.Start and fr.End need not be page-aligned. // - // Preconditions: fr.Length() > 0. At least one reference must be held on - // all pages in fr. + // Preconditions: + // * fr.Length() > 0. + // * At least one reference must be held on all pages in fr. // // Postconditions: The returned mapping is valid as long as at least one // reference is held on the mapped pages. |