[syserror] Add linuxerr package.

Add linuxerr package to replace syserror and syserr errors. This is done
to improve performance comparing/returning errors to on par with
syscall.Errno.

The below linuxerr_test (formerly syserror_test) shows linuxerr.Error
on par with unix.Error (syscall.Errno) as desired.

BenchmarkAssignErrno
BenchmarkAssignErrno-6                  1000000000               0.6291 ns/op
BenchmarkLinuxerrAssignError
BenchmarkLinuxerrAssignError-6          1000000000               0.5808 ns/op
BenchmarkAssignSyserrorError
BenchmarkAssignSyserrorError-6          1000000000               0.6188 ns/op
BenchmarkCompareErrno
BenchmarkCompareErrno-6                 1000000000               0.5041 ns/op
BenchmarkCompareLinuxerrError
BenchmarkCompareLinuxerrError-6         1000000000               0.4660 ns/op
BenchmarkCompareSyserrorError
BenchmarkCompareSyserrorError-6         309026907                3.386 ns/op
BenchmarkSwitchErrno
BenchmarkSwitchErrno-6                  722253750                1.440 ns/op
BenchmarkSwitchLinuxerrError
BenchmarkSwitchLinuxerrError-6          709108542                1.453 ns/op
BenchmarkSwitchSyserrorError
BenchmarkSwitchSyserrorError-6          106331331               11.21 ns/op

PiperOrigin-RevId: 374507431

4 files changed, 242 insertions, 15 deletions

diff --git a/pkg/linuxerr/BUILD b/pkg/linuxerr/BUILD
new file mode 100644
index 000000000..c5abbd34f
--- /dev/null
+++ b/pkg/linuxerr/BUILD
@@ -0,0 +1,20 @@
+load("//tools:defs.bzl", "go_library", "go_test")
+
+package(licenses = ["notice"])
+
+go_library(
+    name = "linuxerr",
+    srcs = ["linuxerr.go"],
+    visibility = ["//visibility:public"],
+    deps = ["//pkg/abi/linux"],
+)
+
+go_test(
+    name = "linuxerr_test",
+    srcs = ["linuxerr_test.go"],
+    deps = [
+        ":linuxerr",
+        "//pkg/syserror",
+        "@org_golang_x_sys//unix:go_default_library",
+    ],
+)
diff --git a/pkg/linuxerr/linuxerr.go b/pkg/linuxerr/linuxerr.go
new file mode 100644
index 000000000..f45caaadf
--- /dev/null
+++ b/pkg/linuxerr/linuxerr.go
@@ -0,0 +1,184 @@
+// 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 linuxerr contains syscall error codes exported as an error interface
+// pointers. This allows for fast comparison and return operations comperable
+// to unix.Errno constants.
+package linuxerr
+
+import (
+	"gvisor.dev/gvisor/pkg/abi/linux"
+)
+
+// Error represents a syscall errno with a descriptive message.
+type Error struct {
+	errno   linux.Errno
+	message string
+}
+
+func new(err linux.Errno, message string) *Error {
+	return &Error{
+		errno:   err,
+		message: message,
+	}
+}
+
+// Error implements error.Error.
+func (e *Error) Error() string { return e.message }
+
+// Errno returns the underlying linux.Errno value.
+func (e *Error) Errno() linux.Errno { return e.errno }
+
+// The following varables have the same meaning as their errno equivalent.
+
+// Errno values from include/uapi/asm-generic/errno-base.h.
+var (
+	EPERM   = new(linux.EPERM, "operation not permitted")
+	ENOENT  = new(linux.ENOENT, "no such file or directory")
+	ESRCH   = new(linux.ESRCH, "no such process")
+	EINTR   = new(linux.EINTR, "interrupted system call")
+	EIO     = new(linux.EIO, "I/O error")
+	ENXIO   = new(linux.ENXIO, "no such device or address")
+	E2BIG   = new(linux.E2BIG, "argument list too long")
+	ENOEXEC = new(linux.ENOEXEC, "exec format error")
+	EBADF   = new(linux.EBADF, "bad file number")
+	ECHILD  = new(linux.ECHILD, "no child processes")
+	EAGAIN  = new(linux.EAGAIN, "try again")
+	ENOMEM  = new(linux.ENOMEM, "out of memory")
+	EACCES  = new(linux.EACCES, "permission denied")
+	EFAULT  = new(linux.EFAULT, "bad address")
+	ENOTBLK = new(linux.ENOTBLK, "block device required")
+	EBUSY   = new(linux.EBUSY, "device or resource busy")
+	EEXIST  = new(linux.EEXIST, "file exists")
+	EXDEV   = new(linux.EXDEV, "cross-device link")
+	ENODEV  = new(linux.ENODEV, "no such device")
+	ENOTDIR = new(linux.ENOTDIR, "not a directory")
+	EISDIR  = new(linux.EISDIR, "is a directory")
+	EINVAL  = new(linux.EINVAL, "invalid argument")
+	ENFILE  = new(linux.ENFILE, "file table overflow")
+	EMFILE  = new(linux.EMFILE, "too many open files")
+	ENOTTY  = new(linux.ENOTTY, "not a typewriter")
+	ETXTBSY = new(linux.ETXTBSY, "text file busy")
+	EFBIG   = new(linux.EFBIG, "file too large")
+	ENOSPC  = new(linux.ENOSPC, "no space left on device")
+	ESPIPE  = new(linux.ESPIPE, "illegal seek")
+	EROFS   = new(linux.EROFS, "read-only file system")
+	EMLINK  = new(linux.EMLINK, "too many links")
+	EPIPE   = new(linux.EPIPE, "broken pipe")
+	EDOM    = new(linux.EDOM, "math argument out of domain of func")
+	ERANGE  = new(linux.ERANGE, "math result not representable")
+)
+
+// Errno values from include/uapi/asm-generic/errno.h.
+var (
+	EDEADLK         = new(linux.EDEADLK, "resource deadlock would occur")
+	ENAMETOOLONG    = new(linux.ENAMETOOLONG, "file name too long")
+	ENOLCK          = new(linux.ENOLCK, "no record locks available")
+	ENOSYS          = new(linux.ENOSYS, "invalid system call number")
+	ENOTEMPTY       = new(linux.ENOTEMPTY, "directory not empty")
+	ELOOP           = new(linux.ELOOP, "too many symbolic links encountered")
+	EWOULDBLOCK     = new(linux.EWOULDBLOCK, "operation would block")
+	ENOMSG          = new(linux.ENOMSG, "no message of desired type")
+	EIDRM           = new(linux.EIDRM, "identifier removed")
+	ECHRNG          = new(linux.ECHRNG, "channel number out of range")
+	EL2NSYNC        = new(linux.EL2NSYNC, "level 2 not synchronized")
+	EL3HLT          = new(linux.EL3HLT, "level 3 halted")
+	EL3RST          = new(linux.EL3RST, "level 3 reset")
+	ELNRNG          = new(linux.ELNRNG, "link number out of range")
+	EUNATCH         = new(linux.EUNATCH, "protocol driver not attached")
+	ENOCSI          = new(linux.ENOCSI, "no CSI structure available")
+	EL2HLT          = new(linux.EL2HLT, "level 2 halted")
+	EBADE           = new(linux.EBADE, "invalid exchange")
+	EBADR           = new(linux.EBADR, "invalid request descriptor")
+	EXFULL          = new(linux.EXFULL, "exchange full")
+	ENOANO          = new(linux.ENOANO, "no anode")
+	EBADRQC         = new(linux.EBADRQC, "invalid request code")
+	EBADSLT         = new(linux.EBADSLT, "invalid slot")
+	EDEADLOCK       = new(linux.EDEADLOCK, EDEADLK.message)
+	EBFONT          = new(linux.EBFONT, "bad font file format")
+	ENOSTR          = new(linux.ENOSTR, "device not a stream")
+	ENODATA         = new(linux.ENODATA, "no data available")
+	ETIME           = new(linux.ETIME, "timer expired")
+	ENOSR           = new(linux.ENOSR, "out of streams resources")
+	ENONET          = new(linux.ENOENT, "machine is not on the network")
+	ENOPKG          = new(linux.ENOPKG, "package not installed")
+	EREMOTE         = new(linux.EREMOTE, "object is remote")
+	ENOLINK         = new(linux.ENOLINK, "link has been severed")
+	EADV            = new(linux.EADV, "advertise error")
+	ESRMNT          = new(linux.ESRMNT, "srmount error")
+	ECOMM           = new(linux.ECOMM, "communication error on send")
+	EPROTO          = new(linux.EPROTO, "protocol error")
+	EMULTIHOP       = new(linux.EMULTIHOP, "multihop attempted")
+	EDOTDOT         = new(linux.EDOTDOT, "RFS specific error")
+	EBADMSG         = new(linux.EBADMSG, "not a data message")
+	EOVERFLOW       = new(linux.EOVERFLOW, "value too large for defined data type")
+	ENOTUNIQ        = new(linux.ENOTUNIQ, "name not unique on network")
+	EBADFD          = new(linux.EBADFD, "file descriptor in bad state")
+	EREMCHG         = new(linux.EREMCHG, "remote address changed")
+	ELIBACC         = new(linux.ELIBACC, "can not access a needed shared library")
+	ELIBBAD         = new(linux.ELIBBAD, "accessing a corrupted shared library")
+	ELIBSCN         = new(linux.ELIBSCN, ".lib section in a.out corrupted")
+	ELIBMAX         = new(linux.ELIBMAX, "attempting to link in too many shared libraries")
+	ELIBEXEC        = new(linux.ELIBEXEC, "cannot exec a shared library directly")
+	EILSEQ          = new(linux.EILSEQ, "illegal byte sequence")
+	ERESTART        = new(linux.ERESTART, "interrupted system call should be restarted")
+	ESTRPIPE        = new(linux.ESTRPIPE, "streams pipe error")
+	EUSERS          = new(linux.EUSERS, "too many users")
+	ENOTSOCK        = new(linux.ENOTSOCK, "socket operation on non-socket")
+	EDESTADDRREQ    = new(linux.EDESTADDRREQ, "destination address required")
+	EMSGSIZE        = new(linux.EMSGSIZE, "message too long")
+	EPROTOTYPE      = new(linux.EPROTOTYPE, "protocol wrong type for socket")
+	ENOPROTOOPT     = new(linux.ENOPROTOOPT, "protocol not available")
+	EPROTONOSUPPORT = new(linux.EPROTONOSUPPORT, "protocol not supported")
+	ESOCKTNOSUPPORT = new(linux.ESOCKTNOSUPPORT, "socket type not supported")
+	EOPNOTSUPP      = new(linux.EOPNOTSUPP, "operation not supported on transport endpoint")
+	EPFNOSUPPORT    = new(linux.EPFNOSUPPORT, "protocol family not supported")
+	EAFNOSUPPORT    = new(linux.EAFNOSUPPORT, "address family not supported by protocol")
+	EADDRINUSE      = new(linux.EADDRINUSE, "address already in use")
+	EADDRNOTAVAIL   = new(linux.EADDRNOTAVAIL, "cannot assign requested address")
+	ENETDOWN        = new(linux.ENETDOWN, "network is down")
+	ENETUNREACH     = new(linux.ENETUNREACH, "network is unreachable")
+	ENETRESET       = new(linux.ENETRESET, "network dropped connection because of reset")
+	ECONNABORTED    = new(linux.ECONNABORTED, "software caused connection abort")
+	ECONNRESET      = new(linux.ECONNRESET, "connection reset by peer")
+	ENOBUFS         = new(linux.ENOBUFS, "no buffer space available")
+	EISCONN         = new(linux.EISCONN, "transport endpoint is already connected")
+	ENOTCONN        = new(linux.ENOTCONN, "transport endpoint is not connected")
+	ESHUTDOWN       = new(linux.ESHUTDOWN, "cannot send after transport endpoint shutdown")
+	ETOOMANYREFS    = new(linux.ETOOMANYREFS, "too many references: cannot splice")
+	ETIMEDOUT       = new(linux.ETIMEDOUT, "connection timed out")
+	ECONNREFUSED    = new(linux.ECONNREFUSED, "connection refused")
+	EHOSTDOWN       = new(linux.EHOSTDOWN, "host is down")
+	EHOSTUNREACH    = new(linux.EHOSTUNREACH, "no route to host")
+	EALREADY        = new(linux.EALREADY, "operation already in progress")
+	EINPROGRESS     = new(linux.EINPROGRESS, "operation now in progress")
+	ESTALE          = new(linux.ESTALE, "stale file handle")
+	EUCLEAN         = new(linux.EUCLEAN, "structure needs cleaning")
+	ENOTNAM         = new(linux.ENOTNAM, "not a XENIX named type file")
+	ENAVAIL         = new(linux.ENAVAIL, "no XENIX semaphores available")
+	EISNAM          = new(linux.EISNAM, "is a named type file")
+	EREMOTEIO       = new(linux.EREMOTEIO, "remote I/O error")
+	EDQUOT          = new(linux.EDQUOT, "quota exceeded")
+	ENOMEDIUM       = new(linux.ENOMEDIUM, "no medium found")
+	EMEDIUMTYPE     = new(linux.EMEDIUMTYPE, "wrong medium type")
+	ECANCELED       = new(linux.ECANCELED, "operation Canceled")
+	ENOKEY          = new(linux.ENOKEY, "required key not available")
+	EKEYEXPIRED     = new(linux.EKEYEXPIRED, "key has expired")
+	EKEYREVOKED     = new(linux.EKEYREVOKED, "key has been revoked")
+	EKEYREJECTED    = new(linux.EKEYREJECTED, "key was rejected by service")
+	EOWNERDEAD      = new(linux.EOWNERDEAD, "owner died")
+	ENOTRECOVERABLE = new(linux.ENOTRECOVERABLE, "state not recoverable")
+	ERFKILL         = new(linux.ERFKILL, "operation not possible due to RF-kill")
+	EHWPOISON       = new(linux.EHWPOISON, "memory page has hardware error")
+)
diff --git a/pkg/syserror/syserror_test.go b/pkg/linuxerr/linuxerr_test.go
index c141e5f6e..d34937e93 100644
--- a/pkg/syserror/syserror_test.go
+++ b/pkg/linuxerr/linuxerr_test.go
@@ -19,6 +19,7 @@ import (
 	"testing"
 
 	"golang.org/x/sys/unix"
+	"gvisor.dev/gvisor/pkg/linuxerr"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
@@ -30,7 +31,13 @@ func BenchmarkAssignErrno(b *testing.B) {
 	}
 }
 
-func BenchmarkAssignError(b *testing.B) {
+func BenchmarkLinuxerrAssignError(b *testing.B) {
+	for i := b.N; i > 0; i-- {
+		globalError = linuxerr.EINVAL
+	}
+}
+
+func BenchmarkAssignSyserrorError(b *testing.B) {
 	for i := b.N; i > 0; i-- {
 		globalError = syserror.EINVAL
 	}
@@ -46,7 +53,17 @@ func BenchmarkCompareErrno(b *testing.B) {
 	}
 }
 
-func BenchmarkCompareError(b *testing.B) {
+func BenchmarkCompareLinuxerrError(b *testing.B) {
+	globalError = linuxerr.E2BIG
+	j := 0
+	for i := b.N; i > 0; i-- {
+		if globalError == linuxerr.EINVAL {
+			j++
+		}
+	}
+}
+
+func BenchmarkCompareSyserrorError(b *testing.B) {
 	globalError = syserror.EAGAIN
 	j := 0
 	for i := b.N; i > 0; i-- {
@@ -62,7 +79,7 @@ func BenchmarkSwitchErrno(b *testing.B) {
 	for i := b.N; i > 0; i-- {
 		switch globalError {
 		case unix.EINVAL:
-			j += 1
+			j++
 		case unix.EINTR:
 			j += 2
 		case unix.EAGAIN:
@@ -71,13 +88,28 @@ func BenchmarkSwitchErrno(b *testing.B) {
 	}
 }
 
-func BenchmarkSwitchError(b *testing.B) {
+func BenchmarkSwitchLinuxerrError(b *testing.B) {
+	globalError = linuxerr.EPERM
+	j := 0
+	for i := b.N; i > 0; i-- {
+		switch globalError {
+		case linuxerr.EINVAL:
+			j++
+		case linuxerr.EINTR:
+			j += 2
+		case linuxerr.EAGAIN:
+			j += 3
+		}
+	}
+}
+
+func BenchmarkSwitchSyserrorError(b *testing.B) {
 	globalError = syserror.EPERM
 	j := 0
 	for i := b.N; i > 0; i-- {
 		switch globalError {
 		case syserror.EINVAL:
-			j += 1
+			j++
 		case syserror.EINTR:
 			j += 2
 		case syserror.EAGAIN:
diff --git a/pkg/syserror/BUILD b/pkg/syserror/BUILD
index 7d2f5adf6..76bee5a64 100644
--- a/pkg/syserror/BUILD
+++ b/pkg/syserror/BUILD
@@ -1,4 +1,4 @@
-load("//tools:defs.bzl", "go_library", "go_test")
+load("//tools:defs.bzl", "go_library")
 
 package(licenses = ["notice"])
 
@@ -8,12 +8,3 @@ go_library(
     visibility = ["//visibility:public"],
     deps = ["@org_golang_x_sys//unix:go_default_library"],
 )
-
-go_test(
-    name = "syserror_test",
-    srcs = ["syserror_test.go"],
-    deps = [
-        ":syserror",
-        "@org_golang_x_sys//unix:go_default_library",
-    ],
-)