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-rw-r--r--pkg/sentry/syscalls/linux/vfs2/BUILD24
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/linux64.go16
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/linux64_override_amd64.go25
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/linux64_override_arm64.go25
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/sys_read.go95
5 files changed, 185 insertions, 0 deletions
diff --git a/pkg/sentry/syscalls/linux/vfs2/BUILD b/pkg/sentry/syscalls/linux/vfs2/BUILD
new file mode 100644
index 000000000..6b8a00b6e
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/BUILD
@@ -0,0 +1,24 @@
+load("//tools:defs.bzl", "go_library")
+
+package(licenses = ["notice"])
+
+go_library(
+ name = "vfs2",
+ srcs = [
+ "linux64.go",
+ "linux64_override_amd64.go",
+ "linux64_override_arm64.go",
+ "sys_read.go",
+ ],
+ visibility = ["//:sandbox"],
+ deps = [
+ "//pkg/sentry/arch",
+ "//pkg/sentry/kernel",
+ "//pkg/sentry/syscalls",
+ "//pkg/sentry/syscalls/linux",
+ "//pkg/sentry/vfs",
+ "//pkg/syserror",
+ "//pkg/usermem",
+ "//pkg/waiter",
+ ],
+)
diff --git a/pkg/sentry/syscalls/linux/vfs2/linux64.go b/pkg/sentry/syscalls/linux/vfs2/linux64.go
new file mode 100644
index 000000000..19ee36081
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/linux64.go
@@ -0,0 +1,16 @@
+// Copyright 2020 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 vfs2 provides syscall implementations that use VFS2.
+package vfs2
diff --git a/pkg/sentry/syscalls/linux/vfs2/linux64_override_amd64.go b/pkg/sentry/syscalls/linux/vfs2/linux64_override_amd64.go
new file mode 100644
index 000000000..c134714ee
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/linux64_override_amd64.go
@@ -0,0 +1,25 @@
+// Copyright 2020 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 vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/syscalls"
+)
+
+// Override syscall table to add syscalls implementations from this package.
+func Override(table map[uintptr]kernel.Syscall) {
+ table[0] = syscalls.Supported("read", Read)
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/linux64_override_arm64.go b/pkg/sentry/syscalls/linux/vfs2/linux64_override_arm64.go
new file mode 100644
index 000000000..6af5c400f
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/linux64_override_arm64.go
@@ -0,0 +1,25 @@
+// Copyright 2020 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 vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/syscalls"
+)
+
+// Override syscall table to add syscalls implementations from this package.
+func Override(table map[uintptr]kernel.Syscall) {
+ table[63] = syscalls.Supported("read", Read)
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/sys_read.go b/pkg/sentry/syscalls/linux/vfs2/sys_read.go
new file mode 100644
index 000000000..b9fb58464
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/sys_read.go
@@ -0,0 +1,95 @@
+// Copyright 2020 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 vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/syscalls/linux"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+ "gvisor.dev/gvisor/pkg/waiter"
+)
+
+// Read implements linux syscall read(2). Note that we try to get a buffer that
+// is exactly the size requested because some applications like qemu expect
+// they can do large reads all at once. Bug for bug. Same for other read
+// calls below.
+func Read(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ addr := args[1].Pointer()
+ size := args[2].SizeT()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // Check that the file is readable.
+ if !file.IsReadable() {
+ return 0, nil, syserror.EBADF
+ }
+
+ // Check that the size is legitimate.
+ si := int(size)
+ if si < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Get the destination of the read.
+ dst, err := t.SingleIOSequence(addr, si, usermem.IOOpts{
+ AddressSpaceActive: true,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+
+ n, err := read(t, file, dst, vfs.ReadOptions{})
+ t.IOUsage().AccountReadSyscall(n)
+ return uintptr(n), nil, linux.HandleIOErrorVFS2(t, n != 0, err, kernel.ERESTARTSYS, "read", file)
+}
+
+func read(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) {
+ n, err := file.Read(t, dst, opts)
+ if err != syserror.ErrWouldBlock {
+ return n, err
+ }
+
+ // Register for notifications.
+ _, ch := waiter.NewChannelEntry(nil)
+ // file.EventRegister(&w, EventMaskRead)
+
+ total := n
+ for {
+ // Shorten dst to reflect bytes previously read.
+ dst = dst.DropFirst(int(n))
+
+ // Issue the request and break out if it completes with anything other than
+ // "would block".
+ n, err := file.Read(t, dst, opts)
+ total += n
+ if err != syserror.ErrWouldBlock {
+ break
+ }
+ if err := t.Block(ch); err != nil {
+ break
+ }
+ }
+ //file.EventUnregister(&w)
+
+ return total, err
+}