diff options
Diffstat (limited to 'pkg/sentry/usermem')
| -rw-r--r-- | pkg/sentry/usermem/bytes_io_unsafe.go | 8 | ||||
| -rw-r--r-- | pkg/sentry/usermem/usermem.go | 7 |
2 files changed, 15 insertions, 0 deletions
diff --git a/pkg/sentry/usermem/bytes_io_unsafe.go b/pkg/sentry/usermem/bytes_io_unsafe.go index 8bdf3a508..7add8bc82 100644 --- a/pkg/sentry/usermem/bytes_io_unsafe.go +++ b/pkg/sentry/usermem/bytes_io_unsafe.go @@ -37,3 +37,11 @@ func (b *BytesIO) CompareAndSwapUint32(ctx context.Context, addr Addr, old, new } return atomicbitops.CompareAndSwapUint32((*uint32)(unsafe.Pointer(&b.Bytes[int(addr)])), old, new), nil } + +// LoadUint32 implements IO.LoadUint32. +func (b *BytesIO) LoadUint32(ctx context.Context, addr Addr, opts IOOpts) (uint32, error) { + if _, err := b.rangeCheck(addr, 4); err != nil { + return 0, err + } + return atomic.LoadUint32((*uint32)(unsafe.Pointer(&b.Bytes[int(addr)]))), nil +} diff --git a/pkg/sentry/usermem/usermem.go b/pkg/sentry/usermem/usermem.go index 75ac4d22d..c3c9c153b 100644 --- a/pkg/sentry/usermem/usermem.go +++ b/pkg/sentry/usermem/usermem.go @@ -103,6 +103,13 @@ type IO interface { // any following locks in the lock order. addr must be aligned to a 4-byte // boundary. CompareAndSwapUint32(ctx context.Context, addr Addr, old, new uint32, opts IOOpts) (uint32, error) + + // LoadUint32 atomically loads the uint32 value at addr and returns it. + // + // Preconditions: The caller must not hold mm.MemoryManager.mappingMu or + // any following locks in the lock order. addr must be aligned to a 4-byte + // boundary. + LoadUint32(ctx context.Context, addr Addr, opts IOOpts) (uint32, error) } // IOOpts contains options applicable to all IO methods. |