Merge branch 'master' into ip-forwarding

- Merges aleksej-paschenko's with HEAD
- Adds vfs2 support for ip_forward

1 files changed, 29 insertions, 17 deletions

diff --git a/pkg/sentry/mm/lifecycle.go b/pkg/sentry/mm/lifecycle.go
index 4e9ca1de6..09dbc06a4 100644
--- a/pkg/sentry/mm/lifecycle.go
+++ b/pkg/sentry/mm/lifecycle.go
@@ -18,27 +18,27 @@ import (
 	"fmt"
 	"sync/atomic"
 
-	"gvisor.dev/gvisor/pkg/atomicbitops"
+	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
-	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/limits"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/pgalloc"
 	"gvisor.dev/gvisor/pkg/sentry/platform"
-	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/usermem"
 )
 
 // NewMemoryManager returns a new MemoryManager with no mappings and 1 user.
-func NewMemoryManager(p platform.Platform, mfp pgalloc.MemoryFileProvider) *MemoryManager {
+func NewMemoryManager(p platform.Platform, mfp pgalloc.MemoryFileProvider, sleepForActivation bool) *MemoryManager {
 	return &MemoryManager{
-		p:           p,
-		mfp:         mfp,
-		haveASIO:    p.SupportsAddressSpaceIO(),
-		privateRefs: &privateRefs{},
-		users:       1,
-		auxv:        arch.Auxv{},
-		dumpability: UserDumpable,
-		aioManager:  aioManager{contexts: make(map[uint64]*AIOContext)},
+		p:                  p,
+		mfp:                mfp,
+		haveASIO:           p.SupportsAddressSpaceIO(),
+		privateRefs:        &privateRefs{},
+		users:              1,
+		auxv:               arch.Auxv{},
+		dumpability:        UserDumpable,
+		aioManager:         aioManager{contexts: make(map[uint64]*AIOContext)},
+		sleepForActivation: sleepForActivation,
 	}
 }
 
@@ -57,6 +57,8 @@ func (mm *MemoryManager) SetMmapLayout(ac arch.Context, r *limits.LimitSet) (arc
 // Fork creates a copy of mm with 1 user, as for Linux syscalls fork() or
 // clone() (without CLONE_VM).
 func (mm *MemoryManager) Fork(ctx context.Context) (*MemoryManager, error) {
+	mm.AddressSpace().PreFork()
+	defer mm.AddressSpace().PostFork()
 	mm.metadataMu.Lock()
 	defer mm.metadataMu.Unlock()
 	mm.mappingMu.RLock()
@@ -80,9 +82,11 @@ func (mm *MemoryManager) Fork(ctx context.Context) (*MemoryManager, error) {
 		envv:                 mm.envv,
 		auxv:                 append(arch.Auxv(nil), mm.auxv...),
 		// IncRef'd below, once we know that there isn't an error.
-		executable:  mm.executable,
-		dumpability: mm.dumpability,
-		aioManager:  aioManager{contexts: make(map[uint64]*AIOContext)},
+		executable:         mm.executable,
+		dumpability:        mm.dumpability,
+		aioManager:         aioManager{contexts: make(map[uint64]*AIOContext)},
+		sleepForActivation: mm.sleepForActivation,
+		vdsoSigReturnAddr:  mm.vdsoSigReturnAddr,
 	}
 
 	// Copy vmas.
@@ -229,7 +233,15 @@ func (mm *MemoryManager) Fork(ctx context.Context) (*MemoryManager, error) {
 // IncUsers increments mm's user count and returns true. If the user count is
 // already 0, IncUsers does nothing and returns false.
 func (mm *MemoryManager) IncUsers() bool {
-	return atomicbitops.IncUnlessZeroInt32(&mm.users)
+	for {
+		users := atomic.LoadInt32(&mm.users)
+		if users == 0 {
+			return false
+		}
+		if atomic.CompareAndSwapInt32(&mm.users, users, users+1) {
+			return true
+		}
+	}
 }
 
 // DecUsers decrements mm's user count. If the user count reaches 0, all
@@ -248,7 +260,7 @@ func (mm *MemoryManager) DecUsers(ctx context.Context) {
 	mm.executable = nil
 	mm.metadataMu.Unlock()
 	if exe != nil {
-		exe.DecRef()
+		exe.DecRef(ctx)
 	}
 
 	mm.activeMu.Lock()