unix: implement EpollCreate using EpollCreate1 on all linux platforms

Most newer architectures (e.g. arm64 or riscv64) don't provide the
epoll_create syscall. Some systems (e.g. Android) block it even if it
were available. In the kernel, the epoll_create syscall is implemented
[1] the same way EpollCreate is implemented in this package for
platforms without the epoll_create syscall. Thus, avoid the separate
wrapper and consistently implement EpollCreate using EpollCreate1.

[1] https://elixir.bootlin.com/linux/v5.15-rc1/source/fs/eventpoll.c#L2006

Change-Id: I8ac11d0de939dafa4b1d189d97d350b9c324c3ab
Reviewed-on: https://go-review.googlesource.com/c/sys/+/349809
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matt Layher <mdlayher@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

unix/syscall_linux.go

@@ -38,6 +38,13 @@ func Creat(path string, mode uint32) (fd int, err error) {
 	return Open(path, O_CREAT|O_WRONLY|O_TRUNC, mode)
 }
 
+func EpollCreate(size int) (fd int, err error) {
+	if size <= 0 {
+		return -1, EINVAL
+	}
+	return EpollCreate1(0)
+}
+
 //sys	FanotifyInit(flags uint, event_f_flags uint) (fd int, err error)
 //sys	fanotifyMark(fd int, flags uint, mask uint64, dirFd int, pathname *byte) (err error)
 

unix/syscall_linux_386.go

@@ -48,7 +48,6 @@ func Pipe2(p []int, flags int) (err error) {
 // 64-bit file system and 32-bit uid calls
 // (386 default is 32-bit file system and 16-bit uid).
 //sys	dup2(oldfd int, newfd int) (err error)
-//sysnb	EpollCreate(size int) (fd int, err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64_64
 //sys	Fchown(fd int, uid int, gid int) (err error) = SYS_FCHOWN32

unix/syscall_linux_amd64.go

@@ -8,7 +8,6 @@
 package unix
 
 //sys	dup2(oldfd int, newfd int) (err error)
-//sysnb	EpollCreate(size int) (fd int, err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)

unix/syscall_linux_arm.go

@@ -73,7 +73,6 @@ func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {
 // 64-bit file system and 32-bit uid calls
 // (16-bit uid calls are not always supported in newer kernels)
 //sys	dup2(oldfd int, newfd int) (err error)
-//sysnb	EpollCreate(size int) (fd int, err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fchown(fd int, uid int, gid int) (err error) = SYS_FCHOWN32
 //sys	Fstat(fd int, stat *Stat_t) (err error) = SYS_FSTAT64

unix/syscall_linux_arm64.go

@@ -9,13 +9,6 @@ package unix
 
 import "unsafe"
 
-func EpollCreate(size int) (fd int, err error) {
-	if size <= 0 {
-		return -1, EINVAL
-	}
-	return EpollCreate1(0)
-}
-
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) = SYS_EPOLL_PWAIT
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)

unix/syscall_linux_mips64x.go

@@ -9,7 +9,6 @@
 package unix
 
 //sys	dup2(oldfd int, newfd int) (err error)
-//sysnb	EpollCreate(size int) (fd int, err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)

unix/syscall_linux_mipsx.go

@@ -16,7 +16,6 @@ import (
 func Syscall9(trap, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2 uintptr, err syscall.Errno)
 
 //sys	dup2(oldfd int, newfd int) (err error)
-//sysnb	EpollCreate(size int) (fd int, err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)

unix/syscall_linux_ppc.go

@@ -13,7 +13,6 @@ import (
 )
 
 //sys	dup2(oldfd int, newfd int) (err error)
-//sysnb	EpollCreate(size int) (fd int, err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fchown(fd int, uid int, gid int) (err error)
 //sys	Fstat(fd int, stat *Stat_t) (err error) = SYS_FSTAT64

unix/syscall_linux_ppc64x.go

@@ -9,7 +9,6 @@
 package unix
 
 //sys	dup2(oldfd int, newfd int) (err error)
-//sysnb	EpollCreate(size int) (fd int, err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)

unix/syscall_linux_riscv64.go

@@ -9,13 +9,6 @@ package unix
 
 import "unsafe"
 
-func EpollCreate(size int) (fd int, err error) {
-	if size <= 0 {
-		return -1, EINVAL
-	}
-	return EpollCreate1(0)
-}
-
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) = SYS_EPOLL_PWAIT
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)

unix/syscall_linux_s390x.go

@@ -12,7 +12,6 @@ import (
 )
 
 //sys	dup2(oldfd int, newfd int) (err error)
-//sysnb	EpollCreate(size int) (fd int, err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)

unix/zsyscall_linux_386.go

@@ -66,17 +66,6 @@ func dup2(oldfd int, newfd int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func EpollCreate(size int) (fd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_EPOLL_CREATE, uintptr(size), 0, 0)
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {

unix/zsyscall_linux_amd64.go

@@ -56,17 +56,6 @@ func dup2(oldfd int, newfd int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func EpollCreate(size int) (fd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_EPOLL_CREATE, uintptr(size), 0, 0)
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {

unix/zsyscall_linux_arm.go

@@ -245,17 +245,6 @@ func dup2(oldfd int, newfd int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func EpollCreate(size int) (fd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_EPOLL_CREATE, uintptr(size), 0, 0)
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {

unix/zsyscall_linux_mips.go

@@ -56,17 +56,6 @@ func dup2(oldfd int, newfd int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func EpollCreate(size int) (fd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_EPOLL_CREATE, uintptr(size), 0, 0)
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {

unix/zsyscall_linux_mips64.go

@@ -56,17 +56,6 @@ func dup2(oldfd int, newfd int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func EpollCreate(size int) (fd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_EPOLL_CREATE, uintptr(size), 0, 0)
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {

unix/zsyscall_linux_mips64le.go

@@ -56,17 +56,6 @@ func dup2(oldfd int, newfd int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func EpollCreate(size int) (fd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_EPOLL_CREATE, uintptr(size), 0, 0)
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {

unix/zsyscall_linux_mipsle.go

@@ -56,17 +56,6 @@ func dup2(oldfd int, newfd int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func EpollCreate(size int) (fd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_EPOLL_CREATE, uintptr(size), 0, 0)
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {

unix/zsyscall_linux_ppc.go

@@ -56,17 +56,6 @@ func dup2(oldfd int, newfd int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func EpollCreate(size int) (fd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_EPOLL_CREATE, uintptr(size), 0, 0)
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {

unix/zsyscall_linux_ppc64.go

@@ -56,17 +56,6 @@ func dup2(oldfd int, newfd int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func EpollCreate(size int) (fd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_EPOLL_CREATE, uintptr(size), 0, 0)
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {

unix/zsyscall_linux_ppc64le.go

@@ -56,17 +56,6 @@ func dup2(oldfd int, newfd int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func EpollCreate(size int) (fd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_EPOLL_CREATE, uintptr(size), 0, 0)
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {

unix/zsyscall_linux_s390x.go

@@ -56,17 +56,6 @@ func dup2(oldfd int, newfd int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func EpollCreate(size int) (fd int, err error) {
-	r0, _, e1 := RawSyscall(SYS_EPOLL_CREATE, uintptr(size), 0, 0)
-	fd = int(r0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {