Merge release-20201208.0-97-g1b66bad7c (automated)

2 files changed, 283 insertions, 283 deletions

diff --git a/pkg/sentry/arch/arch_abi_autogen_unsafe.go b/pkg/sentry/arch/arch_abi_autogen_unsafe.go
index fe68f921d..2ddabb10b 100644
--- a/pkg/sentry/arch/arch_abi_autogen_unsafe.go
+++ b/pkg/sentry/arch/arch_abi_autogen_unsafe.go
@@ -23,71 +23,53 @@ var _ marshal.Marshallable = (*SignalStack)(nil)
 var _ marshal.Marshallable = (*linux.SignalSet)(nil)
 
 // SizeBytes implements marshal.Marshallable.SizeBytes.
-func (s *SignalAct) SizeBytes() int {
-    return 24 +
-        (*linux.SignalSet)(nil).SizeBytes()
+func (s *SignalStack) SizeBytes() int {
+    return 24
 }
 
 // MarshalBytes implements marshal.Marshallable.MarshalBytes.
-func (s *SignalAct) MarshalBytes(dst []byte) {
-    usermem.ByteOrder.PutUint64(dst[:8], uint64(s.Handler))
-    dst = dst[8:]
-    usermem.ByteOrder.PutUint64(dst[:8], uint64(s.Flags))
+func (s *SignalStack) MarshalBytes(dst []byte) {
+    usermem.ByteOrder.PutUint64(dst[:8], uint64(s.Addr))
     dst = dst[8:]
-    usermem.ByteOrder.PutUint64(dst[:8], uint64(s.Restorer))
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Flags))
+    dst = dst[4:]
+    // Padding: dst[:sizeof(uint32)] ~= uint32(0)
+    dst = dst[4:]
+    usermem.ByteOrder.PutUint64(dst[:8], uint64(s.Size))
     dst = dst[8:]
-    s.Mask.MarshalBytes(dst[:s.Mask.SizeBytes()])
-    dst = dst[s.Mask.SizeBytes():]
 }
 
 // UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.
-func (s *SignalAct) UnmarshalBytes(src []byte) {
-    s.Handler = uint64(usermem.ByteOrder.Uint64(src[:8]))
-    src = src[8:]
-    s.Flags = uint64(usermem.ByteOrder.Uint64(src[:8]))
+func (s *SignalStack) UnmarshalBytes(src []byte) {
+    s.Addr = uint64(usermem.ByteOrder.Uint64(src[:8]))
     src = src[8:]
-    s.Restorer = uint64(usermem.ByteOrder.Uint64(src[:8]))
+    s.Flags = uint32(usermem.ByteOrder.Uint32(src[:4]))
+    src = src[4:]
+    // Padding: var _ uint32 ~= src[:sizeof(uint32)]
+    src = src[4:]
+    s.Size = uint64(usermem.ByteOrder.Uint64(src[:8]))
     src = src[8:]
-    s.Mask.UnmarshalBytes(src[:s.Mask.SizeBytes()])
-    src = src[s.Mask.SizeBytes():]
 }
 
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
-func (s *SignalAct) Packed() bool {
-    return s.Mask.Packed()
+func (s *SignalStack) Packed() bool {
+    return true
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
-func (s *SignalAct) MarshalUnsafe(dst []byte) {
-    if s.Mask.Packed() {
-        safecopy.CopyIn(dst, unsafe.Pointer(s))
-    } else {
-        // Type SignalAct doesn't have a packed layout in memory, fallback to MarshalBytes.
-        s.MarshalBytes(dst)
-    }
+func (s *SignalStack) MarshalUnsafe(dst []byte) {
+    safecopy.CopyIn(dst, unsafe.Pointer(s))
 }
 
 // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
-func (s *SignalAct) UnmarshalUnsafe(src []byte) {
-    if s.Mask.Packed() {
-        safecopy.CopyOut(unsafe.Pointer(s), src)
-    } else {
-        // Type SignalAct doesn't have a packed layout in memory, fallback to UnmarshalBytes.
-        s.UnmarshalBytes(src)
-    }
+func (s *SignalStack) UnmarshalUnsafe(src []byte) {
+    safecopy.CopyOut(unsafe.Pointer(s), src)
 }
 
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
-func (s *SignalAct) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
-    if !s.Mask.Packed() {
-        // Type SignalAct doesn't have a packed layout in memory, fall back to MarshalBytes.
-        buf := cc.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
-        s.MarshalBytes(buf) // escapes: fallback.
-        return cc.CopyOutBytes(addr, buf[:limit]) // escapes: okay.
-    }
-
+func (s *SignalStack) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
     // Construct a slice backed by dst's underlying memory.
     var buf []byte
     hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
@@ -104,23 +86,13 @@ func (s *SignalAct) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit in
 
 // CopyOut implements marshal.Marshallable.CopyOut.
 //go:nosplit
-func (s *SignalAct) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
+func (s *SignalStack) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
     return s.CopyOutN(cc, addr, s.SizeBytes())
 }
 
 // CopyIn implements marshal.Marshallable.CopyIn.
 //go:nosplit
-func (s *SignalAct) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
-    if !s.Mask.Packed() {
-        // Type SignalAct doesn't have a packed layout in memory, fall back to UnmarshalBytes.
-        buf := cc.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
-        length, err := cc.CopyInBytes(addr, buf) // escapes: okay.
-        // Unmarshal unconditionally. If we had a short copy-in, this results in a
-        // partially unmarshalled struct.
-        s.UnmarshalBytes(buf) // escapes: fallback.
-        return length, err
-    }
-
+func (s *SignalStack) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
     // Construct a slice backed by dst's underlying memory.
     var buf []byte
     hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
@@ -136,15 +108,7 @@ func (s *SignalAct) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, erro
 }
 
 // WriteTo implements io.WriterTo.WriteTo.
-func (s *SignalAct) WriteTo(writer io.Writer) (int64, error) {
-    if !s.Mask.Packed() {
-        // Type SignalAct doesn't have a packed layout in memory, fall back to MarshalBytes.
-        buf := make([]byte, s.SizeBytes())
-        s.MarshalBytes(buf)
-        length, err := writer.Write(buf)
-        return int64(length), err
-    }
-
+func (s *SignalStack) WriteTo(writer io.Writer) (int64, error) {
     // Construct a slice backed by dst's underlying memory.
     var buf []byte
     hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
@@ -160,53 +124,62 @@ func (s *SignalAct) WriteTo(writer io.Writer) (int64, error) {
 }
 
 // SizeBytes implements marshal.Marshallable.SizeBytes.
-func (s *SignalStack) SizeBytes() int {
-    return 24
+func (s *SignalInfo) SizeBytes() int {
+    return 16 +
+        1*(128-16)
 }
 
 // MarshalBytes implements marshal.Marshallable.MarshalBytes.
-func (s *SignalStack) MarshalBytes(dst []byte) {
-    usermem.ByteOrder.PutUint64(dst[:8], uint64(s.Addr))
-    dst = dst[8:]
-    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Flags))
+func (s *SignalInfo) MarshalBytes(dst []byte) {
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Signo))
+    dst = dst[4:]
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Errno))
+    dst = dst[4:]
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Code))
     dst = dst[4:]
     // Padding: dst[:sizeof(uint32)] ~= uint32(0)
     dst = dst[4:]
-    usermem.ByteOrder.PutUint64(dst[:8], uint64(s.Size))
-    dst = dst[8:]
+    for idx := 0; idx < (128-16); idx++ {
+        dst[0] = byte(s.Fields[idx])
+        dst = dst[1:]
+    }
 }
 
 // UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.
-func (s *SignalStack) UnmarshalBytes(src []byte) {
-    s.Addr = uint64(usermem.ByteOrder.Uint64(src[:8]))
-    src = src[8:]
-    s.Flags = uint32(usermem.ByteOrder.Uint32(src[:4]))
+func (s *SignalInfo) UnmarshalBytes(src []byte) {
+    s.Signo = int32(usermem.ByteOrder.Uint32(src[:4]))
+    src = src[4:]
+    s.Errno = int32(usermem.ByteOrder.Uint32(src[:4]))
+    src = src[4:]
+    s.Code = int32(usermem.ByteOrder.Uint32(src[:4]))
     src = src[4:]
     // Padding: var _ uint32 ~= src[:sizeof(uint32)]
     src = src[4:]
-    s.Size = uint64(usermem.ByteOrder.Uint64(src[:8]))
-    src = src[8:]
+    for idx := 0; idx < (128-16); idx++ {
+        s.Fields[idx] = src[0]
+        src = src[1:]
+    }
 }
 
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
-func (s *SignalStack) Packed() bool {
+func (s *SignalInfo) Packed() bool {
     return true
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
-func (s *SignalStack) MarshalUnsafe(dst []byte) {
+func (s *SignalInfo) MarshalUnsafe(dst []byte) {
     safecopy.CopyIn(dst, unsafe.Pointer(s))
 }
 
 // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
-func (s *SignalStack) UnmarshalUnsafe(src []byte) {
+func (s *SignalInfo) UnmarshalUnsafe(src []byte) {
     safecopy.CopyOut(unsafe.Pointer(s), src)
 }
 
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
-func (s *SignalStack) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
+func (s *SignalInfo) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
     // Construct a slice backed by dst's underlying memory.
     var buf []byte
     hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
@@ -223,13 +196,13 @@ func (s *SignalStack) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit
 
 // CopyOut implements marshal.Marshallable.CopyOut.
 //go:nosplit
-func (s *SignalStack) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
+func (s *SignalInfo) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
     return s.CopyOutN(cc, addr, s.SizeBytes())
 }
 
 // CopyIn implements marshal.Marshallable.CopyIn.
 //go:nosplit
-func (s *SignalStack) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
+func (s *SignalInfo) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
     // Construct a slice backed by dst's underlying memory.
     var buf []byte
     hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
@@ -245,7 +218,7 @@ func (s *SignalStack) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, er
 }
 
 // WriteTo implements io.WriterTo.WriteTo.
-func (s *SignalStack) WriteTo(writer io.Writer) (int64, error) {
+func (s *SignalInfo) WriteTo(writer io.Writer) (int64, error) {
     // Construct a slice backed by dst's underlying memory.
     var buf []byte
     hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
@@ -261,62 +234,71 @@ func (s *SignalStack) WriteTo(writer io.Writer) (int64, error) {
 }
 
 // SizeBytes implements marshal.Marshallable.SizeBytes.
-func (s *SignalInfo) SizeBytes() int {
-    return 16 +
-        1*(128-16)
+func (s *SignalAct) SizeBytes() int {
+    return 24 +
+        (*linux.SignalSet)(nil).SizeBytes()
 }
 
 // MarshalBytes implements marshal.Marshallable.MarshalBytes.
-func (s *SignalInfo) MarshalBytes(dst []byte) {
-    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Signo))
-    dst = dst[4:]
-    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Errno))
-    dst = dst[4:]
-    usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Code))
-    dst = dst[4:]
-    // Padding: dst[:sizeof(uint32)] ~= uint32(0)
-    dst = dst[4:]
-    for idx := 0; idx < (128-16); idx++ {
-        dst[0] = byte(s.Fields[idx])
-        dst = dst[1:]
-    }
+func (s *SignalAct) MarshalBytes(dst []byte) {
+    usermem.ByteOrder.PutUint64(dst[:8], uint64(s.Handler))
+    dst = dst[8:]
+    usermem.ByteOrder.PutUint64(dst[:8], uint64(s.Flags))
+    dst = dst[8:]
+    usermem.ByteOrder.PutUint64(dst[:8], uint64(s.Restorer))
+    dst = dst[8:]
+    s.Mask.MarshalBytes(dst[:s.Mask.SizeBytes()])
+    dst = dst[s.Mask.SizeBytes():]
 }
 
 // UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.
-func (s *SignalInfo) UnmarshalBytes(src []byte) {
-    s.Signo = int32(usermem.ByteOrder.Uint32(src[:4]))
-    src = src[4:]
-    s.Errno = int32(usermem.ByteOrder.Uint32(src[:4]))
-    src = src[4:]
-    s.Code = int32(usermem.ByteOrder.Uint32(src[:4]))
-    src = src[4:]
-    // Padding: var _ uint32 ~= src[:sizeof(uint32)]
-    src = src[4:]
-    for idx := 0; idx < (128-16); idx++ {
-        s.Fields[idx] = src[0]
-        src = src[1:]
-    }
+func (s *SignalAct) UnmarshalBytes(src []byte) {
+    s.Handler = uint64(usermem.ByteOrder.Uint64(src[:8]))
+    src = src[8:]
+    s.Flags = uint64(usermem.ByteOrder.Uint64(src[:8]))
+    src = src[8:]
+    s.Restorer = uint64(usermem.ByteOrder.Uint64(src[:8]))
+    src = src[8:]
+    s.Mask.UnmarshalBytes(src[:s.Mask.SizeBytes()])
+    src = src[s.Mask.SizeBytes():]
 }
 
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
-func (s *SignalInfo) Packed() bool {
-    return true
+func (s *SignalAct) Packed() bool {
+    return s.Mask.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
-func (s *SignalInfo) MarshalUnsafe(dst []byte) {
-    safecopy.CopyIn(dst, unsafe.Pointer(s))
+func (s *SignalAct) MarshalUnsafe(dst []byte) {
+    if s.Mask.Packed() {
+        safecopy.CopyIn(dst, unsafe.Pointer(s))
+    } else {
+        // Type SignalAct doesn't have a packed layout in memory, fallback to MarshalBytes.
+        s.MarshalBytes(dst)
+    }
 }
 
 // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
-func (s *SignalInfo) UnmarshalUnsafe(src []byte) {
-    safecopy.CopyOut(unsafe.Pointer(s), src)
+func (s *SignalAct) UnmarshalUnsafe(src []byte) {
+    if s.Mask.Packed() {
+        safecopy.CopyOut(unsafe.Pointer(s), src)
+    } else {
+        // Type SignalAct doesn't have a packed layout in memory, fallback to UnmarshalBytes.
+        s.UnmarshalBytes(src)
+    }
 }
 
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
-func (s *SignalInfo) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
+func (s *SignalAct) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
+    if !s.Mask.Packed() {
+        // Type SignalAct doesn't have a packed layout in memory, fall back to MarshalBytes.
+        buf := cc.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
+        s.MarshalBytes(buf) // escapes: fallback.
+        return cc.CopyOutBytes(addr, buf[:limit]) // escapes: okay.
+    }
+
     // Construct a slice backed by dst's underlying memory.
     var buf []byte
     hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
@@ -333,13 +315,23 @@ func (s *SignalInfo) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit i
 
 // CopyOut implements marshal.Marshallable.CopyOut.
 //go:nosplit
-func (s *SignalInfo) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
+func (s *SignalAct) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
     return s.CopyOutN(cc, addr, s.SizeBytes())
 }
 
 // CopyIn implements marshal.Marshallable.CopyIn.
 //go:nosplit
-func (s *SignalInfo) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
+func (s *SignalAct) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
+    if !s.Mask.Packed() {
+        // Type SignalAct doesn't have a packed layout in memory, fall back to UnmarshalBytes.
+        buf := cc.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
+        length, err := cc.CopyInBytes(addr, buf) // escapes: okay.
+        // Unmarshal unconditionally. If we had a short copy-in, this results in a
+        // partially unmarshalled struct.
+        s.UnmarshalBytes(buf) // escapes: fallback.
+        return length, err
+    }
+
     // Construct a slice backed by dst's underlying memory.
     var buf []byte
     hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
@@ -355,7 +347,15 @@ func (s *SignalInfo) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, err
 }
 
 // WriteTo implements io.WriterTo.WriteTo.
-func (s *SignalInfo) WriteTo(writer io.Writer) (int64, error) {
+func (s *SignalAct) WriteTo(writer io.Writer) (int64, error) {
+    if !s.Mask.Packed() {
+        // Type SignalAct doesn't have a packed layout in memory, fall back to MarshalBytes.
+        buf := make([]byte, s.SizeBytes())
+        s.MarshalBytes(buf)
+        length, err := writer.Write(buf)
+        return int64(length), err
+    }
+
     // Construct a slice backed by dst's underlying memory.
     var buf []byte
     hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
diff --git a/pkg/sentry/arch/arch_arm64_abi_autogen_unsafe.go b/pkg/sentry/arch/arch_arm64_abi_autogen_unsafe.go
index 95a73e115..aac25375e 100644
--- a/pkg/sentry/arch/arch_arm64_abi_autogen_unsafe.go
+++ b/pkg/sentry/arch/arch_arm64_abi_autogen_unsafe.go
@@ -27,167 +27,6 @@ var _ marshal.Marshallable = (*aarch64Ctx)(nil)
 var _ marshal.Marshallable = (*linux.SignalSet)(nil)
 
 // SizeBytes implements marshal.Marshallable.SizeBytes.
-func (u *UContext64) SizeBytes() int {
-    return 16 +
-        (*SignalStack)(nil).SizeBytes() +
-        (*linux.SignalSet)(nil).SizeBytes() +
-        1*120 +
-        1*8 +
-        (*SignalContext64)(nil).SizeBytes()
-}
-
-// MarshalBytes implements marshal.Marshallable.MarshalBytes.
-func (u *UContext64) MarshalBytes(dst []byte) {
-    usermem.ByteOrder.PutUint64(dst[:8], uint64(u.Flags))
-    dst = dst[8:]
-    usermem.ByteOrder.PutUint64(dst[:8], uint64(u.Link))
-    dst = dst[8:]
-    u.Stack.MarshalBytes(dst[:u.Stack.SizeBytes()])
-    dst = dst[u.Stack.SizeBytes():]
-    u.Sigset.MarshalBytes(dst[:u.Sigset.SizeBytes()])
-    dst = dst[u.Sigset.SizeBytes():]
-    for idx := 0; idx < 120; idx++ {
-        dst[0] = byte(u._pad[idx])
-        dst = dst[1:]
-    }
-    for idx := 0; idx < 8; idx++ {
-        dst[0] = byte(u._pad2[idx])
-        dst = dst[1:]
-    }
-    u.MContext.MarshalBytes(dst[:u.MContext.SizeBytes()])
-    dst = dst[u.MContext.SizeBytes():]
-}
-
-// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.
-func (u *UContext64) UnmarshalBytes(src []byte) {
-    u.Flags = uint64(usermem.ByteOrder.Uint64(src[:8]))
-    src = src[8:]
-    u.Link = uint64(usermem.ByteOrder.Uint64(src[:8]))
-    src = src[8:]
-    u.Stack.UnmarshalBytes(src[:u.Stack.SizeBytes()])
-    src = src[u.Stack.SizeBytes():]
-    u.Sigset.UnmarshalBytes(src[:u.Sigset.SizeBytes()])
-    src = src[u.Sigset.SizeBytes():]
-    for idx := 0; idx < 120; idx++ {
-        u._pad[idx] = src[0]
-        src = src[1:]
-    }
-    for idx := 0; idx < 8; idx++ {
-        u._pad2[idx] = src[0]
-        src = src[1:]
-    }
-    u.MContext.UnmarshalBytes(src[:u.MContext.SizeBytes()])
-    src = src[u.MContext.SizeBytes():]
-}
-
-// Packed implements marshal.Marshallable.Packed.
-//go:nosplit
-func (u *UContext64) Packed() bool {
-    return u.MContext.Packed() && u.Sigset.Packed() && u.Stack.Packed()
-}
-
-// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
-func (u *UContext64) MarshalUnsafe(dst []byte) {
-    if u.MContext.Packed() && u.Sigset.Packed() && u.Stack.Packed() {
-        safecopy.CopyIn(dst, unsafe.Pointer(u))
-    } else {
-        // Type UContext64 doesn't have a packed layout in memory, fallback to MarshalBytes.
-        u.MarshalBytes(dst)
-    }
-}
-
-// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
-func (u *UContext64) UnmarshalUnsafe(src []byte) {
-    if u.MContext.Packed() && u.Sigset.Packed() && u.Stack.Packed() {
-        safecopy.CopyOut(unsafe.Pointer(u), src)
-    } else {
-        // Type UContext64 doesn't have a packed layout in memory, fallback to UnmarshalBytes.
-        u.UnmarshalBytes(src)
-    }
-}
-
-// CopyOutN implements marshal.Marshallable.CopyOutN.
-//go:nosplit
-func (u *UContext64) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
-    if !u.MContext.Packed() && u.Sigset.Packed() && u.Stack.Packed() {
-        // Type UContext64 doesn't have a packed layout in memory, fall back to MarshalBytes.
-        buf := cc.CopyScratchBuffer(u.SizeBytes()) // escapes: okay.
-        u.MarshalBytes(buf) // escapes: fallback.
-        return cc.CopyOutBytes(addr, buf[:limit]) // escapes: okay.
-    }
-
-    // Construct a slice backed by dst's underlying memory.
-    var buf []byte
-    hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
-    hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(u)))
-    hdr.Len = u.SizeBytes()
-    hdr.Cap = u.SizeBytes()
-
-    length, err := cc.CopyOutBytes(addr, buf[:limit]) // escapes: okay.
-    // Since we bypassed the compiler's escape analysis, indicate that u
-    // must live until the use above.
-    runtime.KeepAlive(u) // escapes: replaced by intrinsic.
-    return length, err
-}
-
-// CopyOut implements marshal.Marshallable.CopyOut.
-//go:nosplit
-func (u *UContext64) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
-    return u.CopyOutN(cc, addr, u.SizeBytes())
-}
-
-// CopyIn implements marshal.Marshallable.CopyIn.
-//go:nosplit
-func (u *UContext64) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
-    if !u.MContext.Packed() && u.Sigset.Packed() && u.Stack.Packed() {
-        // Type UContext64 doesn't have a packed layout in memory, fall back to UnmarshalBytes.
-        buf := cc.CopyScratchBuffer(u.SizeBytes()) // escapes: okay.
-        length, err := cc.CopyInBytes(addr, buf) // escapes: okay.
-        // Unmarshal unconditionally. If we had a short copy-in, this results in a
-        // partially unmarshalled struct.
-        u.UnmarshalBytes(buf) // escapes: fallback.
-        return length, err
-    }
-
-    // Construct a slice backed by dst's underlying memory.
-    var buf []byte
-    hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
-    hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(u)))
-    hdr.Len = u.SizeBytes()
-    hdr.Cap = u.SizeBytes()
-
-    length, err := cc.CopyInBytes(addr, buf) // escapes: okay.
-    // Since we bypassed the compiler's escape analysis, indicate that u
-    // must live until the use above.
-    runtime.KeepAlive(u) // escapes: replaced by intrinsic.
-    return length, err
-}
-
-// WriteTo implements io.WriterTo.WriteTo.
-func (u *UContext64) WriteTo(writer io.Writer) (int64, error) {
-    if !u.MContext.Packed() && u.Sigset.Packed() && u.Stack.Packed() {
-        // Type UContext64 doesn't have a packed layout in memory, fall back to MarshalBytes.
-        buf := make([]byte, u.SizeBytes())
-        u.MarshalBytes(buf)
-        length, err := writer.Write(buf)
-        return int64(length), err
-    }
-
-    // Construct a slice backed by dst's underlying memory.
-    var buf []byte
-    hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
-    hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(u)))
-    hdr.Len = u.SizeBytes()
-    hdr.Cap = u.SizeBytes()
-
-    length, err := writer.Write(buf)
-    // Since we bypassed the compiler's escape analysis, indicate that u
-    // must live until the use above.
-    runtime.KeepAlive(u) // escapes: replaced by intrinsic.
-    return int64(length), err
-}
-
-// SizeBytes implements marshal.Marshallable.SizeBytes.
 func (s *SignalContext64) SizeBytes() int {
     return 32 +
         8*31 +
@@ -590,3 +429,164 @@ func (f *FpsimdContext) WriteTo(writer io.Writer) (int64, error) {
     return int64(length), err
 }
 
+// SizeBytes implements marshal.Marshallable.SizeBytes.
+func (u *UContext64) SizeBytes() int {
+    return 16 +
+        (*SignalStack)(nil).SizeBytes() +
+        (*linux.SignalSet)(nil).SizeBytes() +
+        1*120 +
+        1*8 +
+        (*SignalContext64)(nil).SizeBytes()
+}
+
+// MarshalBytes implements marshal.Marshallable.MarshalBytes.
+func (u *UContext64) MarshalBytes(dst []byte) {
+    usermem.ByteOrder.PutUint64(dst[:8], uint64(u.Flags))
+    dst = dst[8:]
+    usermem.ByteOrder.PutUint64(dst[:8], uint64(u.Link))
+    dst = dst[8:]
+    u.Stack.MarshalBytes(dst[:u.Stack.SizeBytes()])
+    dst = dst[u.Stack.SizeBytes():]
+    u.Sigset.MarshalBytes(dst[:u.Sigset.SizeBytes()])
+    dst = dst[u.Sigset.SizeBytes():]
+    for idx := 0; idx < 120; idx++ {
+        dst[0] = byte(u._pad[idx])
+        dst = dst[1:]
+    }
+    for idx := 0; idx < 8; idx++ {
+        dst[0] = byte(u._pad2[idx])
+        dst = dst[1:]
+    }
+    u.MContext.MarshalBytes(dst[:u.MContext.SizeBytes()])
+    dst = dst[u.MContext.SizeBytes():]
+}
+
+// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.
+func (u *UContext64) UnmarshalBytes(src []byte) {
+    u.Flags = uint64(usermem.ByteOrder.Uint64(src[:8]))
+    src = src[8:]
+    u.Link = uint64(usermem.ByteOrder.Uint64(src[:8]))
+    src = src[8:]
+    u.Stack.UnmarshalBytes(src[:u.Stack.SizeBytes()])
+    src = src[u.Stack.SizeBytes():]
+    u.Sigset.UnmarshalBytes(src[:u.Sigset.SizeBytes()])
+    src = src[u.Sigset.SizeBytes():]
+    for idx := 0; idx < 120; idx++ {
+        u._pad[idx] = src[0]
+        src = src[1:]
+    }
+    for idx := 0; idx < 8; idx++ {
+        u._pad2[idx] = src[0]
+        src = src[1:]
+    }
+    u.MContext.UnmarshalBytes(src[:u.MContext.SizeBytes()])
+    src = src[u.MContext.SizeBytes():]
+}
+
+// Packed implements marshal.Marshallable.Packed.
+//go:nosplit
+func (u *UContext64) Packed() bool {
+    return u.MContext.Packed() && u.Sigset.Packed() && u.Stack.Packed()
+}
+
+// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
+func (u *UContext64) MarshalUnsafe(dst []byte) {
+    if u.MContext.Packed() && u.Sigset.Packed() && u.Stack.Packed() {
+        safecopy.CopyIn(dst, unsafe.Pointer(u))
+    } else {
+        // Type UContext64 doesn't have a packed layout in memory, fallback to MarshalBytes.
+        u.MarshalBytes(dst)
+    }
+}
+
+// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
+func (u *UContext64) UnmarshalUnsafe(src []byte) {
+    if u.MContext.Packed() && u.Sigset.Packed() && u.Stack.Packed() {
+        safecopy.CopyOut(unsafe.Pointer(u), src)
+    } else {
+        // Type UContext64 doesn't have a packed layout in memory, fallback to UnmarshalBytes.
+        u.UnmarshalBytes(src)
+    }
+}
+
+// CopyOutN implements marshal.Marshallable.CopyOutN.
+//go:nosplit
+func (u *UContext64) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
+    if !u.MContext.Packed() && u.Sigset.Packed() && u.Stack.Packed() {
+        // Type UContext64 doesn't have a packed layout in memory, fall back to MarshalBytes.
+        buf := cc.CopyScratchBuffer(u.SizeBytes()) // escapes: okay.
+        u.MarshalBytes(buf) // escapes: fallback.
+        return cc.CopyOutBytes(addr, buf[:limit]) // escapes: okay.
+    }
+
+    // Construct a slice backed by dst's underlying memory.
+    var buf []byte
+    hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
+    hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(u)))
+    hdr.Len = u.SizeBytes()
+    hdr.Cap = u.SizeBytes()
+
+    length, err := cc.CopyOutBytes(addr, buf[:limit]) // escapes: okay.
+    // Since we bypassed the compiler's escape analysis, indicate that u
+    // must live until the use above.
+    runtime.KeepAlive(u) // escapes: replaced by intrinsic.
+    return length, err
+}
+
+// CopyOut implements marshal.Marshallable.CopyOut.
+//go:nosplit
+func (u *UContext64) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
+    return u.CopyOutN(cc, addr, u.SizeBytes())
+}
+
+// CopyIn implements marshal.Marshallable.CopyIn.
+//go:nosplit
+func (u *UContext64) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
+    if !u.MContext.Packed() && u.Sigset.Packed() && u.Stack.Packed() {
+        // Type UContext64 doesn't have a packed layout in memory, fall back to UnmarshalBytes.
+        buf := cc.CopyScratchBuffer(u.SizeBytes()) // escapes: okay.
+        length, err := cc.CopyInBytes(addr, buf) // escapes: okay.
+        // Unmarshal unconditionally. If we had a short copy-in, this results in a
+        // partially unmarshalled struct.
+        u.UnmarshalBytes(buf) // escapes: fallback.
+        return length, err
+    }
+
+    // Construct a slice backed by dst's underlying memory.
+    var buf []byte
+    hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
+    hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(u)))
+    hdr.Len = u.SizeBytes()
+    hdr.Cap = u.SizeBytes()
+
+    length, err := cc.CopyInBytes(addr, buf) // escapes: okay.
+    // Since we bypassed the compiler's escape analysis, indicate that u
+    // must live until the use above.
+    runtime.KeepAlive(u) // escapes: replaced by intrinsic.
+    return length, err
+}
+
+// WriteTo implements io.WriterTo.WriteTo.
+func (u *UContext64) WriteTo(writer io.Writer) (int64, error) {
+    if !u.MContext.Packed() && u.Sigset.Packed() && u.Stack.Packed() {
+        // Type UContext64 doesn't have a packed layout in memory, fall back to MarshalBytes.
+        buf := make([]byte, u.SizeBytes())
+        u.MarshalBytes(buf)
+        length, err := writer.Write(buf)
+        return int64(length), err
+    }
+
+    // Construct a slice backed by dst's underlying memory.
+    var buf []byte
+    hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
+    hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(u)))
+    hdr.Len = u.SizeBytes()
+    hdr.Cap = u.SizeBytes()
+
+    length, err := writer.Write(buf)
+    // Since we bypassed the compiler's escape analysis, indicate that u
+    // must live until the use above.
+    runtime.KeepAlive(u) // escapes: replaced by intrinsic.
+    return int64(length), err
+}
+