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-rw-r--r--pkg/gohacks/BUILD10
-rw-r--r--pkg/gohacks/gohacks_test.go97
-rw-r--r--pkg/gohacks/gohacks_unsafe.go14
-rw-r--r--pkg/marshal/marshal.go3
-rw-r--r--pkg/safecopy/safecopy_test.go62
-rw-r--r--pkg/sentry/time/BUILD1
-rw-r--r--pkg/sync/BUILD1
-rw-r--r--pkg/sync/generic_seqatomic_unsafe.go3
-rw-r--r--pkg/sync/runtime_unsafe.go14
-rw-r--r--pkg/sync/seqatomictest/BUILD1
10 files changed, 128 insertions, 78 deletions
diff --git a/pkg/gohacks/BUILD b/pkg/gohacks/BUILD
index 35683fe98..b4e05f922 100644
--- a/pkg/gohacks/BUILD
+++ b/pkg/gohacks/BUILD
@@ -1,4 +1,4 @@
-load("//tools:defs.bzl", "go_library")
+load("//tools:defs.bzl", "go_library", "go_test")
package(licenses = ["notice"])
@@ -10,3 +10,11 @@ go_library(
stateify = False,
visibility = ["//:sandbox"],
)
+
+go_test(
+ name = "gohacks_test",
+ size = "small",
+ srcs = ["gohacks_test.go"],
+ library = ":gohacks",
+ deps = ["@org_golang_x_sys//unix:go_default_library"],
+)
diff --git a/pkg/gohacks/gohacks_test.go b/pkg/gohacks/gohacks_test.go
new file mode 100644
index 000000000..e18c8abc7
--- /dev/null
+++ b/pkg/gohacks/gohacks_test.go
@@ -0,0 +1,97 @@
+// Copyright 2021 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package gohacks
+
+import (
+ "io/ioutil"
+ "math/rand"
+ "os"
+ "runtime/debug"
+ "testing"
+
+ "golang.org/x/sys/unix"
+)
+
+func randBuf(size int) []byte {
+ b := make([]byte, size)
+ for i := range b {
+ b[i] = byte(rand.Intn(256))
+ }
+ return b
+}
+
+// Size of a page in bytes. Cloned from hostarch.PageSize to avoid a circular
+// dependency.
+const pageSize = 4096
+
+func testCopy(dst, src []byte) (panicked bool) {
+ defer func() {
+ if r := recover(); r != nil {
+ panicked = true
+ }
+ }()
+ debug.SetPanicOnFault(true)
+ copy(dst, src)
+ return panicked
+}
+
+func TestSegVOnMemmove(t *testing.T) {
+ // Test that SIGSEGVs received by runtime.memmove when *not* doing
+ // CopyIn or CopyOut work gets propagated to the runtime.
+ const bufLen = pageSize
+ a, err := unix.Mmap(-1, 0, bufLen, unix.PROT_NONE, unix.MAP_ANON|unix.MAP_PRIVATE)
+ if err != nil {
+ t.Fatalf("Mmap failed: %v", err)
+
+ }
+ defer unix.Munmap(a)
+ b := randBuf(bufLen)
+
+ if !testCopy(b, a) {
+ t.Fatalf("testCopy didn't panic when it should have")
+ }
+
+ if !testCopy(a, b) {
+ t.Fatalf("testCopy didn't panic when it should have")
+ }
+}
+
+func TestSigbusOnMemmove(t *testing.T) {
+ // Test that SIGBUS received by runtime.memmove when *not* doing
+ // CopyIn or CopyOut work gets propagated to the runtime.
+ const bufLen = pageSize
+ f, err := ioutil.TempFile("", "sigbus_test")
+ if err != nil {
+ t.Fatalf("TempFile failed: %v", err)
+ }
+ os.Remove(f.Name())
+ defer f.Close()
+
+ a, err := unix.Mmap(int(f.Fd()), 0, bufLen, unix.PROT_READ|unix.PROT_WRITE, unix.MAP_SHARED)
+ if err != nil {
+ t.Fatalf("Mmap failed: %v", err)
+
+ }
+ defer unix.Munmap(a)
+ b := randBuf(bufLen)
+
+ if !testCopy(b, a) {
+ t.Fatalf("testCopy didn't panic when it should have")
+ }
+
+ if !testCopy(a, b) {
+ t.Fatalf("testCopy didn't panic when it should have")
+ }
+}
diff --git a/pkg/gohacks/gohacks_unsafe.go b/pkg/gohacks/gohacks_unsafe.go
index 10bbb1f58..374aac2b4 100644
--- a/pkg/gohacks/gohacks_unsafe.go
+++ b/pkg/gohacks/gohacks_unsafe.go
@@ -75,3 +75,17 @@ func StringFromImmutableBytes(bs []byte) string {
// strings.Builder.String().
return *(*string)(unsafe.Pointer(&bs))
}
+
+// Note that go:linkname silently doesn't work if the local name is exported,
+// necessitating an indirection for exported functions.
+
+// Memmove is runtime.memmove, exported for SeqAtomicLoad/SeqAtomicTryLoad<T>.
+//
+//go:nosplit
+func Memmove(to, from unsafe.Pointer, n uintptr) {
+ memmove(to, from, n)
+}
+
+//go:linkname memmove runtime.memmove
+//go:noescape
+func memmove(to, from unsafe.Pointer, n uintptr)
diff --git a/pkg/marshal/marshal.go b/pkg/marshal/marshal.go
index eb036feae..7da450ce8 100644
--- a/pkg/marshal/marshal.go
+++ b/pkg/marshal/marshal.go
@@ -166,6 +166,9 @@ type Marshallable interface {
// %s is the first argument to the slice clause. This directive is not supported
// for newtypes on arrays.
//
+// Note: Partial copies are not supported for Slice API UnmarshalUnsafe and
+// MarshalUnsafe.
+//
// The slice clause also takes an optional second argument, which must be the
// value "inner":
//
diff --git a/pkg/safecopy/safecopy_test.go b/pkg/safecopy/safecopy_test.go
index 611f36253..55743e69c 100644
--- a/pkg/safecopy/safecopy_test.go
+++ b/pkg/safecopy/safecopy_test.go
@@ -19,8 +19,6 @@ import (
"fmt"
"io/ioutil"
"math/rand"
- "os"
- "runtime/debug"
"testing"
"unsafe"
@@ -568,63 +566,3 @@ func TestCompareAndSwapUint32BusError(t *testing.T) {
}
})
}
-
-func testCopy(dst, src []byte) (panicked bool) {
- defer func() {
- if r := recover(); r != nil {
- panicked = true
- }
- }()
- debug.SetPanicOnFault(true)
- copy(dst, src)
- return
-}
-
-func TestSegVOnMemmove(t *testing.T) {
- // Test that SIGSEGVs received by runtime.memmove when *not* doing
- // CopyIn or CopyOut work gets propagated to the runtime.
- const bufLen = pageSize
- a, err := unix.Mmap(-1, 0, bufLen, unix.PROT_NONE, unix.MAP_ANON|unix.MAP_PRIVATE)
- if err != nil {
- t.Fatalf("Mmap failed: %v", err)
-
- }
- defer unix.Munmap(a)
- b := randBuf(bufLen)
-
- if !testCopy(b, a) {
- t.Fatalf("testCopy didn't panic when it should have")
- }
-
- if !testCopy(a, b) {
- t.Fatalf("testCopy didn't panic when it should have")
- }
-}
-
-func TestSigbusOnMemmove(t *testing.T) {
- // Test that SIGBUS received by runtime.memmove when *not* doing
- // CopyIn or CopyOut work gets propagated to the runtime.
- const bufLen = pageSize
- f, err := ioutil.TempFile("", "sigbus_test")
- if err != nil {
- t.Fatalf("TempFile failed: %v", err)
- }
- os.Remove(f.Name())
- defer f.Close()
-
- a, err := unix.Mmap(int(f.Fd()), 0, bufLen, unix.PROT_READ|unix.PROT_WRITE, unix.MAP_SHARED)
- if err != nil {
- t.Fatalf("Mmap failed: %v", err)
-
- }
- defer unix.Munmap(a)
- b := randBuf(bufLen)
-
- if !testCopy(b, a) {
- t.Fatalf("testCopy didn't panic when it should have")
- }
-
- if !testCopy(a, b) {
- t.Fatalf("testCopy didn't panic when it should have")
- }
-}
diff --git a/pkg/sentry/time/BUILD b/pkg/sentry/time/BUILD
index 87d8687ce..1f617ca8f 100644
--- a/pkg/sentry/time/BUILD
+++ b/pkg/sentry/time/BUILD
@@ -32,6 +32,7 @@ go_library(
],
visibility = ["//:sandbox"],
deps = [
+ "//pkg/gohacks",
"//pkg/log",
"//pkg/metric",
"//pkg/sync",
diff --git a/pkg/sync/BUILD b/pkg/sync/BUILD
index b2c5229e7..8b3a11c64 100644
--- a/pkg/sync/BUILD
+++ b/pkg/sync/BUILD
@@ -43,6 +43,7 @@ go_template(
],
deps = [
":sync",
+ "//pkg/gohacks",
],
)
diff --git a/pkg/sync/generic_seqatomic_unsafe.go b/pkg/sync/generic_seqatomic_unsafe.go
index 82b676abf..9578c9c52 100644
--- a/pkg/sync/generic_seqatomic_unsafe.go
+++ b/pkg/sync/generic_seqatomic_unsafe.go
@@ -10,6 +10,7 @@ package seqatomic
import (
"unsafe"
+ "gvisor.dev/gvisor/pkg/gohacks"
"gvisor.dev/gvisor/pkg/sync"
)
@@ -39,7 +40,7 @@ func SeqAtomicTryLoad(seq *sync.SeqCount, epoch sync.SeqCountEpoch, ptr *Value)
// runtime.RaceDisable() doesn't actually stop the race detector, so it
// can't help us here. Instead, call runtime.memmove directly, which is
// not instrumented by the race detector.
- sync.Memmove(unsafe.Pointer(&val), unsafe.Pointer(ptr), unsafe.Sizeof(val))
+ gohacks.Memmove(unsafe.Pointer(&val), unsafe.Pointer(ptr), unsafe.Sizeof(val))
} else {
// This is ~40% faster for short reads than going through memmove.
val = *ptr
diff --git a/pkg/sync/runtime_unsafe.go b/pkg/sync/runtime_unsafe.go
index 158985709..39c766331 100644
--- a/pkg/sync/runtime_unsafe.go
+++ b/pkg/sync/runtime_unsafe.go
@@ -17,20 +17,6 @@ import (
"unsafe"
)
-// Note that go:linkname silently doesn't work if the local name is exported,
-// necessitating an indirection for exported functions.
-
-// Memmove is runtime.memmove, exported for SeqAtomicLoad/SeqAtomicTryLoad<T>.
-//
-//go:nosplit
-func Memmove(to, from unsafe.Pointer, n uintptr) {
- memmove(to, from, n)
-}
-
-//go:linkname memmove runtime.memmove
-//go:noescape
-func memmove(to, from unsafe.Pointer, n uintptr)
-
// Gopark is runtime.gopark. Gopark calls unlockf(pointer to runtime.g, lock);
// if unlockf returns true, Gopark blocks until Goready(pointer to runtime.g)
// is called. unlockf and its callees must be nosplit and norace, since stack
diff --git a/pkg/sync/seqatomictest/BUILD b/pkg/sync/seqatomictest/BUILD
index 5c38c783e..5f9164117 100644
--- a/pkg/sync/seqatomictest/BUILD
+++ b/pkg/sync/seqatomictest/BUILD
@@ -18,6 +18,7 @@ go_library(
name = "seqatomic",
srcs = ["seqatomic_int_unsafe.go"],
deps = [
+ "//pkg/gohacks",
"//pkg/sync",
],
)
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-28 02:13:39 +0000