diff options
Diffstat (limited to 'pkg/sentry/mm/syscalls.go')
| -rw-r--r-- | pkg/sentry/mm/syscalls.go | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/pkg/sentry/mm/syscalls.go b/pkg/sentry/mm/syscalls.go index 21aeabde8..b0622b0c3 100644 --- a/pkg/sentry/mm/syscalls.go +++ b/pkg/sentry/mm/syscalls.go @@ -20,6 +20,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/abi/linux" "gvisor.googlesource.com/gvisor/pkg/sentry/context" + "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/futex" "gvisor.googlesource.com/gvisor/pkg/sentry/limits" "gvisor.googlesource.com/gvisor/pkg/sentry/memmap" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" @@ -793,6 +794,40 @@ func (mm *MemoryManager) Sync(ctx context.Context, addr usermem.Addr, length uin return nil } +// GetSharedFutexKey is used by kernel.futexChecker.GetSharedKey to implement +// futex.Checker.GetSharedKey. +func (mm *MemoryManager) GetSharedFutexKey(ctx context.Context, addr usermem.Addr) (futex.Key, error) { + ar, ok := addr.ToRange(4) // sizeof(int32) + if !ok { + return futex.Key{}, syserror.EFAULT + } + + mm.mappingMu.RLock() + defer mm.mappingMu.RUnlock() + vseg, _, err := mm.getVMAsLocked(ctx, ar, usermem.Read, false) + if err != nil { + return futex.Key{}, err + } + vma := vseg.ValuePtr() + + if vma.private { + return futex.Key{ + Kind: futex.KindSharedPrivate, + Offset: uint64(addr), + }, nil + } + + if vma.id != nil { + vma.id.IncRef() + } + return futex.Key{ + Kind: futex.KindSharedMappable, + Mappable: vma.mappable, + MappingIdentity: vma.id, + Offset: vseg.mappableOffsetAt(addr), + }, nil +} + // VirtualMemorySize returns the combined length in bytes of all mappings in // mm. func (mm *MemoryManager) VirtualMemorySize() uint64 { |