syscall: exec_linux.go: support platforms without SYS_DUP2
Updates #9974
This change is in preparation for merging the arm64 platform.
Arm64 does not support SYS_DUP2 at all, so define a new constant to be
the minimum dup(2) version supported. This constant defaults to SYS_DUP2
on all existing platforms.
Change-Id: If405878105082c7c880f8541c1491970124c9ce4
Reviewed-on: https://go-review.googlesource.com/7123
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
diff --git a/src/syscall/exec_linux.go b/src/syscall/exec_linux.go
index 03dd5c5..2e0577c 100644
--- a/src/syscall/exec_linux.go
+++ b/src/syscall/exec_linux.go
@@ -214,7 +214,7 @@
// Pass 1: look for fd[i] < i and move those up above len(fd)
// so that pass 2 won't stomp on an fd it needs later.
if pipe < nextfd {
- _, _, err1 = RawSyscall(SYS_DUP2, uintptr(pipe), uintptr(nextfd), 0)
+ _, _, err1 = RawSyscall(_SYS_dup, uintptr(pipe), uintptr(nextfd), 0)
if err1 != 0 {
goto childerror
}
@@ -224,7 +224,7 @@
}
for i = 0; i < len(fd); i++ {
if fd[i] >= 0 && fd[i] < int(i) {
- _, _, err1 = RawSyscall(SYS_DUP2, uintptr(fd[i]), uintptr(nextfd), 0)
+ _, _, err1 = RawSyscall(_SYS_dup, uintptr(fd[i]), uintptr(nextfd), 0)
if err1 != 0 {
goto childerror
}
@@ -254,7 +254,7 @@
}
// The new fd is created NOT close-on-exec,
// which is exactly what we want.
- _, _, err1 = RawSyscall(SYS_DUP2, uintptr(fd[i]), uintptr(i), 0)
+ _, _, err1 = RawSyscall(_SYS_dup, uintptr(fd[i]), uintptr(i), 0)
if err1 != 0 {
goto childerror
}
diff --git a/src/syscall/syscall_linux_386.go b/src/syscall/syscall_linux_386.go
index 0dcc6be..61ff233 100644
--- a/src/syscall/syscall_linux_386.go
+++ b/src/syscall/syscall_linux_386.go
@@ -9,6 +9,8 @@
import "unsafe"
+const _SYS_dup = SYS_DUP2
+
func Getpagesize() int { return 4096 }
func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
diff --git a/src/syscall/syscall_linux_amd64.go b/src/syscall/syscall_linux_amd64.go
index 8d0777c..ff00ed5 100644
--- a/src/syscall/syscall_linux_amd64.go
+++ b/src/syscall/syscall_linux_amd64.go
@@ -4,6 +4,8 @@
package syscall
+const _SYS_dup = SYS_DUP2
+
//sysnb Dup2(oldfd int, newfd int) (err error)
//sys Fchown(fd int, uid int, gid int) (err error)
//sys Fstat(fd int, stat *Stat_t) (err error)
diff --git a/src/syscall/syscall_linux_arm.go b/src/syscall/syscall_linux_arm.go
index ebbaa17..862c01c 100644
--- a/src/syscall/syscall_linux_arm.go
+++ b/src/syscall/syscall_linux_arm.go
@@ -6,6 +6,8 @@
import "unsafe"
+const _SYS_dup = SYS_DUP2
+
func Getpagesize() int { return 4096 }
func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
diff --git a/src/syscall/syscall_linux_ppc64x.go b/src/syscall/syscall_linux_ppc64x.go
index c266c85..fcf1d7b 100644
--- a/src/syscall/syscall_linux_ppc64x.go
+++ b/src/syscall/syscall_linux_ppc64x.go
@@ -7,6 +7,8 @@
package syscall
+const _SYS_dup = SYS_DUP2
+
//sysnb Dup2(oldfd int, newfd int) (err error)
//sys Fchown(fd int, uid int, gid int) (err error)
//sys Fstat(fd int, stat *Stat_t) (err error)
