Merge release-20201208.0-91-g85c1c3ed4 (automated)

5 files changed, 683 insertions, 614 deletions

diff --git a/pkg/sentry/arch/arch_abi_autogen_unsafe.go b/pkg/sentry/arch/arch_abi_autogen_unsafe.go
index fe68f921d..1bd458b68 100644
--- a/pkg/sentry/arch/arch_abi_autogen_unsafe.go
+++ b/pkg/sentry/arch/arch_abi_autogen_unsafe.go
@@ -23,6 +23,116 @@ var _ marshal.Marshallable = (*SignalStack)(nil)
 var _ marshal.Marshallable = (*linux.SignalSet)(nil)
 
 // SizeBytes implements marshal.Marshallable.SizeBytes.
+func (s *SignalInfo) SizeBytes() int {
+    return 16 +
+        1*(128-16)
+}
+
+// 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:]
+    }
+}
+
+// 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:]
+    }
+}
+
+// Packed implements marshal.Marshallable.Packed.
+//go:nosplit
+func (s *SignalInfo) Packed() bool {
+    return true
+}
+
+// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
+func (s *SignalInfo) MarshalUnsafe(dst []byte) {
+    safecopy.CopyIn(dst, unsafe.Pointer(s))
+}
+
+// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
+func (s *SignalInfo) UnmarshalUnsafe(src []byte) {
+    safecopy.CopyOut(unsafe.Pointer(s), src)
+}
+
+// CopyOutN implements marshal.Marshallable.CopyOutN.
+//go:nosplit
+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))
+    hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(s)))
+    hdr.Len = s.SizeBytes()
+    hdr.Cap = s.SizeBytes()
+
+    length, err := cc.CopyOutBytes(addr, buf[:limit]) // escapes: okay.
+    // Since we bypassed the compiler's escape analysis, indicate that s
+    // must live until the use above.
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
+    return length, err
+}
+
+// CopyOut implements marshal.Marshallable.CopyOut.
+//go:nosplit
+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 *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))
+    hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(s)))
+    hdr.Len = s.SizeBytes()
+    hdr.Cap = s.SizeBytes()
+
+    length, err := cc.CopyInBytes(addr, buf) // escapes: okay.
+    // Since we bypassed the compiler's escape analysis, indicate that s
+    // must live until the use above.
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
+    return length, err
+}
+
+// WriteTo implements io.WriterTo.WriteTo.
+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))
+    hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(s)))
+    hdr.Len = s.SizeBytes()
+    hdr.Cap = s.SizeBytes()
+
+    length, err := writer.Write(buf)
+    // Since we bypassed the compiler's escape analysis, indicate that s
+    // must live until the use above.
+    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
+    return int64(length), err
+}
+
+// SizeBytes implements marshal.Marshallable.SizeBytes.
 func (s *SignalAct) SizeBytes() int {
     return 24 +
         (*linux.SignalSet)(nil).SizeBytes()
@@ -260,113 +370,3 @@ func (s *SignalStack) WriteTo(writer io.Writer) (int64, error) {
     return int64(length), err
 }
 
-// SizeBytes implements marshal.Marshallable.SizeBytes.
-func (s *SignalInfo) SizeBytes() int {
-    return 16 +
-        1*(128-16)
-}
-
-// 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:]
-    }
-}
-
-// 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:]
-    }
-}
-
-// Packed implements marshal.Marshallable.Packed.
-//go:nosplit
-func (s *SignalInfo) Packed() bool {
-    return true
-}
-
-// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
-func (s *SignalInfo) MarshalUnsafe(dst []byte) {
-    safecopy.CopyIn(dst, unsafe.Pointer(s))
-}
-
-// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
-func (s *SignalInfo) UnmarshalUnsafe(src []byte) {
-    safecopy.CopyOut(unsafe.Pointer(s), src)
-}
-
-// CopyOutN implements marshal.Marshallable.CopyOutN.
-//go:nosplit
-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))
-    hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(s)))
-    hdr.Len = s.SizeBytes()
-    hdr.Cap = s.SizeBytes()
-
-    length, err := cc.CopyOutBytes(addr, buf[:limit]) // escapes: okay.
-    // Since we bypassed the compiler's escape analysis, indicate that s
-    // must live until the use above.
-    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
-    return length, err
-}
-
-// CopyOut implements marshal.Marshallable.CopyOut.
-//go:nosplit
-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 *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))
-    hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(s)))
-    hdr.Len = s.SizeBytes()
-    hdr.Cap = s.SizeBytes()
-
-    length, err := cc.CopyInBytes(addr, buf) // escapes: okay.
-    // Since we bypassed the compiler's escape analysis, indicate that s
-    // must live until the use above.
-    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
-    return length, err
-}
-
-// WriteTo implements io.WriterTo.WriteTo.
-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))
-    hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(s)))
-    hdr.Len = s.SizeBytes()
-    hdr.Cap = s.SizeBytes()
-
-    length, err := writer.Write(buf)
-    // Since we bypassed the compiler's escape analysis, indicate that s
-    // must live until the use above.
-    runtime.KeepAlive(s) // escapes: replaced by intrinsic.
-    return int64(length), err
-}
-
diff --git a/pkg/sentry/arch/arch_amd64_abi_autogen_unsafe.go b/pkg/sentry/arch/arch_amd64_abi_autogen_unsafe.go
index 466bf889a..cdbc88377 100644
--- a/pkg/sentry/arch/arch_amd64_abi_autogen_unsafe.go
+++ b/pkg/sentry/arch/arch_amd64_abi_autogen_unsafe.go
@@ -25,6 +25,149 @@ var _ marshal.Marshallable = (*UContext64)(nil)
 var _ marshal.Marshallable = (*linux.SignalSet)(nil)
 
 // SizeBytes implements marshal.Marshallable.SizeBytes.
+func (u *UContext64) SizeBytes() int {
+    return 16 +
+        (*SignalStack)(nil).SizeBytes() +
+        (*SignalContext64)(nil).SizeBytes() +
+        (*linux.SignalSet)(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.MContext.MarshalBytes(dst[:u.MContext.SizeBytes()])
+    dst = dst[u.MContext.SizeBytes():]
+    u.Sigset.MarshalBytes(dst[:u.Sigset.SizeBytes()])
+    dst = dst[u.Sigset.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.MContext.UnmarshalBytes(src[:u.MContext.SizeBytes()])
+    src = src[u.MContext.SizeBytes():]
+    u.Sigset.UnmarshalBytes(src[:u.Sigset.SizeBytes()])
+    src = src[u.Sigset.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 184 +
         (*linux.SignalSet)(nil).SizeBytes() +
@@ -262,146 +405,3 @@ func (s *SignalContext64) 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() +
-        (*SignalContext64)(nil).SizeBytes() +
-        (*linux.SignalSet)(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.MContext.MarshalBytes(dst[:u.MContext.SizeBytes()])
-    dst = dst[u.MContext.SizeBytes():]
-    u.Sigset.MarshalBytes(dst[:u.Sigset.SizeBytes()])
-    dst = dst[u.Sigset.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.MContext.UnmarshalBytes(src[:u.MContext.SizeBytes()])
-    src = src[u.MContext.SizeBytes():]
-    u.Sigset.UnmarshalBytes(src[:u.Sigset.SizeBytes()])
-    src = src[u.Sigset.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
-}
-
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
+}
+
diff --git a/pkg/sentry/control/pprof.go b/pkg/sentry/control/pprof.go
index 91b8fb44f..b78e29416 100644
--- a/pkg/sentry/control/pprof.go
+++ b/pkg/sentry/control/pprof.go
@@ -15,10 +15,10 @@
 package control
 
 import (
-	"errors"
 	"runtime"
 	"runtime/pprof"
 	"runtime/trace"
+	"time"
 
 	"gvisor.dev/gvisor/pkg/fd"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
@@ -26,184 +26,253 @@ import (
 	"gvisor.dev/gvisor/pkg/urpc"
 )
 
-var errNoOutput = errors.New("no output writer provided")
+// Profile includes profile-related RPC stubs. It provides a way to
+// control the built-in runtime profiling facilities.
+//
+// The profile object must be instantied via NewProfile.
+type Profile struct {
+	// kernel is the kernel under profile. It's immutable.
+	kernel *kernel.Kernel
 
-// ProfileOpts contains options for the StartCPUProfile/Goroutine RPC call.
-type ProfileOpts struct {
-	// File is the filesystem path for the profile.
-	File string `json:"path"`
+	// cpuMu protects CPU profiling.
+	cpuMu sync.Mutex
 
-	// FilePayload is the destination for the profiling output.
-	urpc.FilePayload
+	// blockMu protects block profiling.
+	blockMu sync.Mutex
+
+	// mutexMu protects mutex profiling.
+	mutexMu sync.Mutex
+
+	// traceMu protects trace profiling.
+	traceMu sync.Mutex
+
+	// done is closed when profiling is done.
+	done chan struct{}
 }
 
-// Profile includes profile-related RPC stubs. It provides a way to
-// control the built-in pprof facility in sentry via sentryctl.
-//
-// The following options to sentryctl are added:
+// NewProfile returns a new Profile object, and a stop callback.
 //
-// - collect CPU profile on-demand.
-//   sentryctl -pid <pid> pprof-cpu-start
-//   sentryctl -pid <pid> pprof-cpu-stop
-//
-// - dump out the stack trace of current go routines.
-//   sentryctl -pid <pid> pprof-goroutine
-type Profile struct {
-	// Kernel is the kernel under profile. It's immutable.
-	Kernel *kernel.Kernel
+// The stop callback should be used at most once.
+func NewProfile(k *kernel.Kernel) (*Profile, func()) {
+	p := &Profile{
+		kernel: k,
+		done:   make(chan struct{}),
+	}
+	return p, func() {
+		close(p.done)
+	}
+}
 
-	// mu protects the fields below.
-	mu sync.Mutex
+// CPUProfileOpts contains options specifically for CPU profiles.
+type CPUProfileOpts struct {
+	// FilePayload is the destination for the profiling output.
+	urpc.FilePayload
 
-	// cpuFile is the current CPU profile output file.
-	cpuFile *fd.FD
+	// Duration is the duration of the profile.
+	Duration time.Duration `json:"duration"`
 
-	// traceFile is the current execution trace output file.
-	traceFile *fd.FD
+	// Hz is the rate, which may be zero.
+	Hz int `json:"hz"`
 }
 
-// StartCPUProfile is an RPC stub which starts recording the CPU profile in a
-// file.
-func (p *Profile) StartCPUProfile(o *ProfileOpts, _ *struct{}) error {
+// CPU is an RPC stub which collects a CPU profile.
+func (p *Profile) CPU(o *CPUProfileOpts, _ *struct{}) error {
 	if len(o.FilePayload.Files) < 1 {
-		return errNoOutput
+		return nil // Allowed.
 	}
 
 	output, err := fd.NewFromFile(o.FilePayload.Files[0])
 	if err != nil {
 		return err
 	}
+	defer output.Close()
 
-	p.mu.Lock()
-	defer p.mu.Unlock()
+	p.cpuMu.Lock()
+	defer p.cpuMu.Unlock()
 
 	// Returns an error if profiling is already started.
+	if o.Hz != 0 {
+		runtime.SetCPUProfileRate(o.Hz)
+	}
 	if err := pprof.StartCPUProfile(output); err != nil {
-		output.Close()
 		return err
 	}
+	defer pprof.StopCPUProfile()
 
-	p.cpuFile = output
-	return nil
-}
-
-// StopCPUProfile is an RPC stub which stops the CPU profiling and flush out the
-// profile data. It takes no argument.
-func (p *Profile) StopCPUProfile(_, _ *struct{}) error {
-	p.mu.Lock()
-	defer p.mu.Unlock()
-
-	if p.cpuFile == nil {
-		return errors.New("CPU profiling not started")
+	// Collect the profile.
+	select {
+	case <-time.After(o.Duration):
+	case <-p.done:
 	}
 
-	pprof.StopCPUProfile()
-	p.cpuFile.Close()
-	p.cpuFile = nil
 	return nil
 }
 
-// HeapProfile generates a heap profile for the sentry.
-func (p *Profile) HeapProfile(o *ProfileOpts, _ *struct{}) error {
+// HeapProfileOpts contains options specifically for heap profiles.
+type HeapProfileOpts struct {
+	// FilePayload is the destination for the profiling output.
+	urpc.FilePayload
+}
+
+// Heap generates a heap profile.
+func (p *Profile) Heap(o *HeapProfileOpts, _ *struct{}) error {
 	if len(o.FilePayload.Files) < 1 {
-		return errNoOutput
+		return nil // Allowed.
 	}
+
 	output := o.FilePayload.Files[0]
 	defer output.Close()
+
 	runtime.GC() // Get up-to-date statistics.
-	if err := pprof.WriteHeapProfile(output); err != nil {
-		return err
-	}
-	return nil
+	return pprof.WriteHeapProfile(output)
+}
+
+// GoroutineProfileOpts contains options specifically for goroutine profiles.
+type GoroutineProfileOpts struct {
+	// FilePayload is the destination for the profiling output.
+	urpc.FilePayload
 }
 
-// GoroutineProfile is an RPC stub which dumps out the stack trace for all
-// running goroutines.
-func (p *Profile) GoroutineProfile(o *ProfileOpts, _ *struct{}) error {
+// Goroutine dumps out the stack trace for all running goroutines.
+func (p *Profile) Goroutine(o *GoroutineProfileOpts, _ *struct{}) error {
 	if len(o.FilePayload.Files) < 1 {
-		return errNoOutput
+		return nil // Allowed.
 	}
+
 	output := o.FilePayload.Files[0]
 	defer output.Close()
-	if err := pprof.Lookup("goroutine").WriteTo(output, 2); err != nil {
-		return err
-	}
-	return nil
+
+	return pprof.Lookup("goroutine").WriteTo(output, 2)
+}
+
+// BlockProfileOpts contains options specifically for block profiles.
+type BlockProfileOpts struct {
+	// FilePayload is the destination for the profiling output.
+	urpc.FilePayload
+
+	// Duration is the duration of the profile.
+	Duration time.Duration `json:"duration"`
+
+	// Rate is the block profile rate.
+	Rate int `json:"rate"`
 }
 
-// BlockProfile is an RPC stub which dumps out the stack trace that led to
-// blocking on synchronization primitives.
-func (p *Profile) BlockProfile(o *ProfileOpts, _ *struct{}) error {
+// Block dumps a blocking profile.
+func (p *Profile) Block(o *BlockProfileOpts, _ *struct{}) error {
 	if len(o.FilePayload.Files) < 1 {
-		return errNoOutput
+		return nil // Allowed.
 	}
+
 	output := o.FilePayload.Files[0]
 	defer output.Close()
-	if err := pprof.Lookup("block").WriteTo(output, 0); err != nil {
-		return err
+
+	p.blockMu.Lock()
+	defer p.blockMu.Unlock()
+
+	// Always set the rate. We then wait to collect a profile at this rate,
+	// and disable when we're done.
+	rate := 1
+	if o.Rate != 0 {
+		rate = o.Rate
 	}
-	return nil
+	runtime.SetBlockProfileRate(rate)
+	defer runtime.SetBlockProfileRate(0)
+
+	// Collect the profile.
+	select {
+	case <-time.After(o.Duration):
+	case <-p.done:
+	}
+
+	return pprof.Lookup("block").WriteTo(output, 0)
+}
+
+// MutexProfileOpts contains options specifically for mutex profiles.
+type MutexProfileOpts struct {
+	// FilePayload is the destination for the profiling output.
+	urpc.FilePayload
+
+	// Duration is the duration of the profile.
+	Duration time.Duration `json:"duration"`
+
+	// Fraction is the mutex profile fraction.
+	Fraction int `json:"fraction"`
 }
 
-// MutexProfile is an RPC stub which dumps out the stack trace of holders of
-// contended mutexes.
-func (p *Profile) MutexProfile(o *ProfileOpts, _ *struct{}) error {
+// Mutex dumps a mutex profile.
+func (p *Profile) Mutex(o *MutexProfileOpts, _ *struct{}) error {
 	if len(o.FilePayload.Files) < 1 {
-		return errNoOutput
+		return nil // Allowed.
 	}
+
 	output := o.FilePayload.Files[0]
 	defer output.Close()
-	if err := pprof.Lookup("mutex").WriteTo(output, 0); err != nil {
-		return err
+
+	p.mutexMu.Lock()
+	defer p.mutexMu.Unlock()
+
+	// Always set the fraction.
+	fraction := 1
+	if o.Fraction != 0 {
+		fraction = o.Fraction
 	}
-	return nil
+	runtime.SetMutexProfileFraction(fraction)
+	defer runtime.SetMutexProfileFraction(0)
+
+	// Collect the profile.
+	select {
+	case <-time.After(o.Duration):
+	case <-p.done:
+	}
+
+	return pprof.Lookup("mutex").WriteTo(output, 0)
 }
 
-// StartTrace is an RPC stub which starts collection of an execution trace.
-func (p *Profile) StartTrace(o *ProfileOpts, _ *struct{}) error {
+// TraceProfileOpts contains options specifically for traces.
+type TraceProfileOpts struct {
+	// FilePayload is the destination for the profiling output.
+	urpc.FilePayload
+
+	// Duration is the duration of the profile.
+	Duration time.Duration `json:"duration"`
+}
+
+// Trace is an RPC stub which starts collection of an execution trace.
+func (p *Profile) Trace(o *TraceProfileOpts, _ *struct{}) error {
 	if len(o.FilePayload.Files) < 1 {
-		return errNoOutput
+		return nil // Allowed.
 	}
 
 	output, err := fd.NewFromFile(o.FilePayload.Files[0])
 	if err != nil {
 		return err
 	}
+	defer output.Close()
 
-	p.mu.Lock()
-	defer p.mu.Unlock()
+	p.traceMu.Lock()
+	defer p.traceMu.Unlock()
 
 	// Returns an error if profiling is already started.
 	if err := trace.Start(output); err != nil {
 		output.Close()
 		return err
 	}
+	defer trace.Stop()
 
 	// Ensure all trace contexts are registered.
-	p.Kernel.RebuildTraceContexts()
-
-	p.traceFile = output
-	return nil
-}
-
-// StopTrace is an RPC stub which stops collection of an ongoing execution
-// trace and flushes the trace data. It takes no argument.
-func (p *Profile) StopTrace(_, _ *struct{}) error {
-	p.mu.Lock()
-	defer p.mu.Unlock()
+	p.kernel.RebuildTraceContexts()
 
-	if p.traceFile == nil {
-		return errors.New("execution tracing not started")
+	// Wait for the trace.
+	select {
+	case <-time.After(o.Duration):
+	case <-p.done:
 	}
 
 	// Similarly to the case above, if tasks have not ended traces, we will
 	// lose information. Thus we need to rebuild the tasks in order to have
 	// complete information. This will not lose information if multiple
 	// traces are overlapping.
-	p.Kernel.RebuildTraceContexts()
+	p.kernel.RebuildTraceContexts()
 
-	trace.Stop()
-	p.traceFile.Close()
-	p.traceFile = nil
 	return nil
 }
diff --git a/pkg/sentry/syscalls/linux/linux_abi_autogen_unsafe.go b/pkg/sentry/syscalls/linux/linux_abi_autogen_unsafe.go
index 6886c63d1..956643160 100644
--- a/pkg/sentry/syscalls/linux/linux_abi_autogen_unsafe.go
+++ b/pkg/sentry/syscalls/linux/linux_abi_autogen_unsafe.go
@@ -458,26 +458,49 @@ func (u *userSockFprog) WriteTo(writer io.Writer) (int64, error) {
 }
 
 // SizeBytes implements marshal.Marshallable.SizeBytes.
-func (m *multipleMessageHeader64) SizeBytes() int {
-    return 8 +
-        (*MessageHeader64)(nil).SizeBytes()
+func (m *MessageHeader64) SizeBytes() int {
+    return 56
 }
 
 // MarshalBytes implements marshal.Marshallable.MarshalBytes.
-func (m *multipleMessageHeader64) MarshalBytes(dst []byte) {
-    m.msgHdr.MarshalBytes(dst[:m.msgHdr.SizeBytes()])
-    dst = dst[m.msgHdr.SizeBytes():]
-    usermem.ByteOrder.PutUint32(dst[:4], uint32(m.msgLen))
+func (m *MessageHeader64) MarshalBytes(dst []byte) {
+    usermem.ByteOrder.PutUint64(dst[:8], uint64(m.Name))
+    dst = dst[8:]
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(m.NameLen))
+    dst = dst[4:]
+    // Padding: dst[:sizeof(uint32)] ~= uint32(0)
+    dst = dst[4:]
+    usermem.ByteOrder.PutUint64(dst[:8], uint64(m.Iov))
+    dst = dst[8:]
+    usermem.ByteOrder.PutUint64(dst[:8], uint64(m.IovLen))
+    dst = dst[8:]
+    usermem.ByteOrder.PutUint64(dst[:8], uint64(m.Control))
+    dst = dst[8:]
+    usermem.ByteOrder.PutUint64(dst[:8], uint64(m.ControlLen))
+    dst = dst[8:]
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(m.Flags))
     dst = dst[4:]
     // Padding: dst[:sizeof(int32)] ~= int32(0)
     dst = dst[4:]
 }
 
 // UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.
-func (m *multipleMessageHeader64) UnmarshalBytes(src []byte) {
-    m.msgHdr.UnmarshalBytes(src[:m.msgHdr.SizeBytes()])
-    src = src[m.msgHdr.SizeBytes():]
-    m.msgLen = uint32(usermem.ByteOrder.Uint32(src[:4]))
+func (m *MessageHeader64) UnmarshalBytes(src []byte) {
+    m.Name = uint64(usermem.ByteOrder.Uint64(src[:8]))
+    src = src[8:]
+    m.NameLen = uint32(usermem.ByteOrder.Uint32(src[:4]))
+    src = src[4:]
+    // Padding: var _ uint32 ~= src[:sizeof(uint32)]
+    src = src[4:]
+    m.Iov = uint64(usermem.ByteOrder.Uint64(src[:8]))
+    src = src[8:]
+    m.IovLen = uint64(usermem.ByteOrder.Uint64(src[:8]))
+    src = src[8:]
+    m.Control = uint64(usermem.ByteOrder.Uint64(src[:8]))
+    src = src[8:]
+    m.ControlLen = uint64(usermem.ByteOrder.Uint64(src[:8]))
+    src = src[8:]
+    m.Flags = int32(usermem.ByteOrder.Uint32(src[:4]))
     src = src[4:]
     // Padding: var _ int32 ~= src[:sizeof(int32)]
     src = src[4:]
@@ -485,40 +508,23 @@ func (m *multipleMessageHeader64) UnmarshalBytes(src []byte) {
 
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
-func (m *multipleMessageHeader64) Packed() bool {
-    return m.msgHdr.Packed()
+func (m *MessageHeader64) Packed() bool {
+    return true
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
-func (m *multipleMessageHeader64) MarshalUnsafe(dst []byte) {
-    if m.msgHdr.Packed() {
-        safecopy.CopyIn(dst, unsafe.Pointer(m))
-    } else {
-        // Type multipleMessageHeader64 doesn't have a packed layout in memory, fallback to MarshalBytes.
-        m.MarshalBytes(dst)
-    }
+func (m *MessageHeader64) MarshalUnsafe(dst []byte) {
+    safecopy.CopyIn(dst, unsafe.Pointer(m))
 }
 
 // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
-func (m *multipleMessageHeader64) UnmarshalUnsafe(src []byte) {
-    if m.msgHdr.Packed() {
-        safecopy.CopyOut(unsafe.Pointer(m), src)
-    } else {
-        // Type multipleMessageHeader64 doesn't have a packed layout in memory, fallback to UnmarshalBytes.
-        m.UnmarshalBytes(src)
-    }
+func (m *MessageHeader64) UnmarshalUnsafe(src []byte) {
+    safecopy.CopyOut(unsafe.Pointer(m), src)
 }
 
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
-func (m *multipleMessageHeader64) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
-    if !m.msgHdr.Packed() {
-        // Type multipleMessageHeader64 doesn't have a packed layout in memory, fall back to MarshalBytes.
-        buf := cc.CopyScratchBuffer(m.SizeBytes()) // escapes: okay.
-        m.MarshalBytes(buf) // escapes: fallback.
-        return cc.CopyOutBytes(addr, buf[:limit]) // escapes: okay.
-    }
-
+func (m *MessageHeader64) 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))
@@ -535,23 +541,13 @@ func (m *multipleMessageHeader64) CopyOutN(cc marshal.CopyContext, addr usermem.
 
 // CopyOut implements marshal.Marshallable.CopyOut.
 //go:nosplit
-func (m *multipleMessageHeader64) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
+func (m *MessageHeader64) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
     return m.CopyOutN(cc, addr, m.SizeBytes())
 }
 
 // CopyIn implements marshal.Marshallable.CopyIn.
 //go:nosplit
-func (m *multipleMessageHeader64) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
-    if !m.msgHdr.Packed() {
-        // Type multipleMessageHeader64 doesn't have a packed layout in memory, fall back to UnmarshalBytes.
-        buf := cc.CopyScratchBuffer(m.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.
-        m.UnmarshalBytes(buf) // escapes: fallback.
-        return length, err
-    }
-
+func (m *MessageHeader64) 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))
@@ -567,15 +563,7 @@ func (m *multipleMessageHeader64) CopyIn(cc marshal.CopyContext, addr usermem.Ad
 }
 
 // WriteTo implements io.WriterTo.WriteTo.
-func (m *multipleMessageHeader64) WriteTo(writer io.Writer) (int64, error) {
-    if !m.msgHdr.Packed() {
-        // Type multipleMessageHeader64 doesn't have a packed layout in memory, fall back to MarshalBytes.
-        buf := make([]byte, m.SizeBytes())
-        m.MarshalBytes(buf)
-        length, err := writer.Write(buf)
-        return int64(length), err
-    }
-
+func (m *MessageHeader64) WriteTo(writer io.Writer) (int64, error) {
     // Construct a slice backed by dst's underlying memory.
     var buf []byte
     hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
@@ -591,49 +579,26 @@ func (m *multipleMessageHeader64) WriteTo(writer io.Writer) (int64, error) {
 }
 
 // SizeBytes implements marshal.Marshallable.SizeBytes.
-func (m *MessageHeader64) SizeBytes() int {
-    return 56
+func (m *multipleMessageHeader64) SizeBytes() int {
+    return 8 +
+        (*MessageHeader64)(nil).SizeBytes()
 }
 
 // MarshalBytes implements marshal.Marshallable.MarshalBytes.
-func (m *MessageHeader64) MarshalBytes(dst []byte) {
-    usermem.ByteOrder.PutUint64(dst[:8], uint64(m.Name))
-    dst = dst[8:]
-    usermem.ByteOrder.PutUint32(dst[:4], uint32(m.NameLen))
-    dst = dst[4:]
-    // Padding: dst[:sizeof(uint32)] ~= uint32(0)
-    dst = dst[4:]
-    usermem.ByteOrder.PutUint64(dst[:8], uint64(m.Iov))
-    dst = dst[8:]
-    usermem.ByteOrder.PutUint64(dst[:8], uint64(m.IovLen))
-    dst = dst[8:]
-    usermem.ByteOrder.PutUint64(dst[:8], uint64(m.Control))
-    dst = dst[8:]
-    usermem.ByteOrder.PutUint64(dst[:8], uint64(m.ControlLen))
-    dst = dst[8:]
-    usermem.ByteOrder.PutUint32(dst[:4], uint32(m.Flags))
+func (m *multipleMessageHeader64) MarshalBytes(dst []byte) {
+    m.msgHdr.MarshalBytes(dst[:m.msgHdr.SizeBytes()])
+    dst = dst[m.msgHdr.SizeBytes():]
+    usermem.ByteOrder.PutUint32(dst[:4], uint32(m.msgLen))
     dst = dst[4:]
     // Padding: dst[:sizeof(int32)] ~= int32(0)
     dst = dst[4:]
 }
 
 // UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.
-func (m *MessageHeader64) UnmarshalBytes(src []byte) {
-    m.Name = uint64(usermem.ByteOrder.Uint64(src[:8]))
-    src = src[8:]
-    m.NameLen = uint32(usermem.ByteOrder.Uint32(src[:4]))
-    src = src[4:]
-    // Padding: var _ uint32 ~= src[:sizeof(uint32)]
-    src = src[4:]
-    m.Iov = uint64(usermem.ByteOrder.Uint64(src[:8]))
-    src = src[8:]
-    m.IovLen = uint64(usermem.ByteOrder.Uint64(src[:8]))
-    src = src[8:]
-    m.Control = uint64(usermem.ByteOrder.Uint64(src[:8]))
-    src = src[8:]
-    m.ControlLen = uint64(usermem.ByteOrder.Uint64(src[:8]))
-    src = src[8:]
-    m.Flags = int32(usermem.ByteOrder.Uint32(src[:4]))
+func (m *multipleMessageHeader64) UnmarshalBytes(src []byte) {
+    m.msgHdr.UnmarshalBytes(src[:m.msgHdr.SizeBytes()])
+    src = src[m.msgHdr.SizeBytes():]
+    m.msgLen = uint32(usermem.ByteOrder.Uint32(src[:4]))
     src = src[4:]
     // Padding: var _ int32 ~= src[:sizeof(int32)]
     src = src[4:]
@@ -641,23 +606,40 @@ func (m *MessageHeader64) UnmarshalBytes(src []byte) {
 
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
-func (m *MessageHeader64) Packed() bool {
-    return true
+func (m *multipleMessageHeader64) Packed() bool {
+    return m.msgHdr.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
-func (m *MessageHeader64) MarshalUnsafe(dst []byte) {
-    safecopy.CopyIn(dst, unsafe.Pointer(m))
+func (m *multipleMessageHeader64) MarshalUnsafe(dst []byte) {
+    if m.msgHdr.Packed() {
+        safecopy.CopyIn(dst, unsafe.Pointer(m))
+    } else {
+        // Type multipleMessageHeader64 doesn't have a packed layout in memory, fallback to MarshalBytes.
+        m.MarshalBytes(dst)
+    }
 }
 
 // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
-func (m *MessageHeader64) UnmarshalUnsafe(src []byte) {
-    safecopy.CopyOut(unsafe.Pointer(m), src)
+func (m *multipleMessageHeader64) UnmarshalUnsafe(src []byte) {
+    if m.msgHdr.Packed() {
+        safecopy.CopyOut(unsafe.Pointer(m), src)
+    } else {
+        // Type multipleMessageHeader64 doesn't have a packed layout in memory, fallback to UnmarshalBytes.
+        m.UnmarshalBytes(src)
+    }
 }
 
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
-func (m *MessageHeader64) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
+func (m *multipleMessageHeader64) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
+    if !m.msgHdr.Packed() {
+        // Type multipleMessageHeader64 doesn't have a packed layout in memory, fall back to MarshalBytes.
+        buf := cc.CopyScratchBuffer(m.SizeBytes()) // escapes: okay.
+        m.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))
@@ -674,13 +656,23 @@ func (m *MessageHeader64) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, li
 
 // CopyOut implements marshal.Marshallable.CopyOut.
 //go:nosplit
-func (m *MessageHeader64) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
+func (m *multipleMessageHeader64) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
     return m.CopyOutN(cc, addr, m.SizeBytes())
 }
 
 // CopyIn implements marshal.Marshallable.CopyIn.
 //go:nosplit
-func (m *MessageHeader64) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
+func (m *multipleMessageHeader64) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) {
+    if !m.msgHdr.Packed() {
+        // Type multipleMessageHeader64 doesn't have a packed layout in memory, fall back to UnmarshalBytes.
+        buf := cc.CopyScratchBuffer(m.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.
+        m.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))
@@ -696,7 +688,15 @@ func (m *MessageHeader64) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int
 }
 
 // WriteTo implements io.WriterTo.WriteTo.
-func (m *MessageHeader64) WriteTo(writer io.Writer) (int64, error) {
+func (m *multipleMessageHeader64) WriteTo(writer io.Writer) (int64, error) {
+    if !m.msgHdr.Packed() {
+        // Type multipleMessageHeader64 doesn't have a packed layout in memory, fall back to MarshalBytes.
+        buf := make([]byte, m.SizeBytes())
+        m.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))