Imported Upstream version 59upstream/59

1 files changed, 20 insertions, 16 deletions

diff --git a/src/pkg/syscall/exec_plan9.go b/src/pkg/syscall/exec_plan9.go
index 962b39b78..66ab1fced 100644
--- a/src/pkg/syscall/exec_plan9.go
+++ b/src/pkg/syscall/exec_plan9.go
@@ -62,7 +62,7 @@ var ForkLock sync.RWMutex
 
 // Convert array of string to array
 // of NUL-terminated byte pointer.
-func StringArrayPtr(ss []string) []*byte {
+func StringSlicePtr(ss []string) []*byte {
 	bb := make([]*byte, len(ss)+1)
 	for i := 0; i < len(ss); i++ {
 		bb[i] = StringBytePtr(ss[i])
@@ -169,7 +169,7 @@ func init() {
 // no rescheduling, no malloc calls, and no new stack segments.
 // The calls to RawSyscall are okay because they are assembly
 // functions that do not grow the stack.
-func forkAndExecInChild(argv0 *byte, argv []*byte, envv []envItem, chroot, dir *byte, attr *ProcAttr, fdsToClose []int, pipe int) (pid int, err Error) {
+func forkAndExecInChild(argv0 *byte, argv []*byte, envv []envItem, dir *byte, attr *ProcAttr, fdsToClose []int, pipe int, rflag int) (pid int, err Error) {
 	// Declare all variables at top in case any
 	// declarations require heap allocation (e.g., errbuf).
 	var (
@@ -190,7 +190,7 @@ func forkAndExecInChild(argv0 *byte, argv []*byte, envv []envItem, chroot, dir *
 
 	// About to call fork.
 	// No more allocation or calls of non-assembly functions.
-	r1, _, _ = RawSyscall(SYS_RFORK, uintptr(RFPROC|RFFDG|RFREND|clearenv), 0, 0)
+	r1, _, _ = RawSyscall(SYS_RFORK, uintptr(RFPROC|RFFDG|RFREND|clearenv|rflag), 0, 0)
 
 	if r1 != 0 {
 		if int(r1) == -1 {
@@ -338,14 +338,18 @@ type envItem struct {
 }
 
 type ProcAttr struct {
-	Dir    string   // Current working directory.
-	Env    []string // Environment.
-	Files  []int    // File descriptors.
-	Chroot string   // Chroot.
+	Dir   string   // Current working directory.
+	Env   []string // Environment.
+	Files []int    // File descriptors.
+	Sys   *SysProcAttr
 }
 
-var zeroAttributes ProcAttr
+type SysProcAttr struct {
+	Rfork int // additional flags to pass to rfork
+}
 
+var zeroProcAttr ProcAttr
+var zeroSysProcAttr SysProcAttr
 
 func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err Error) {
 	var (
@@ -356,7 +360,11 @@ func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err Error)
 	)
 
 	if attr == nil {
-		attr = &zeroAttributes
+		attr = &zeroProcAttr
+	}
+	sys := attr.Sys
+	if sys == nil {
+		sys = &zeroSysProcAttr
 	}
 
 	p[0] = -1
@@ -364,12 +372,8 @@ func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err Error)
 
 	// Convert args to C form.
 	argv0p := StringBytePtr(argv0)
-	argvp := StringArrayPtr(argv)
+	argvp := StringSlicePtr(argv)
 
-	var chroot *byte
-	if attr.Chroot != "" {
-		chroot = StringBytePtr(attr.Chroot)
-	}
 	var dir *byte
 	if attr.Dir != "" {
 		dir = StringBytePtr(attr.Dir)
@@ -439,7 +443,7 @@ func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err Error)
 	fdsToClose = append(fdsToClose, p[0])
 
 	// Kick off child.
-	pid, err = forkAndExecInChild(argv0p, argvp, envvParsed, chroot, dir, attr, fdsToClose, p[1])
+	pid, err = forkAndExecInChild(argv0p, argvp, envvParsed, dir, attr, fdsToClose, p[1], sys.Rfork)
 
 	if err != nil {
 		if p[0] >= 0 {
@@ -514,7 +518,7 @@ func Exec(argv0 string, argv []string, envv []string) (err Error) {
 
 	_, _, e := Syscall(SYS_EXEC,
 		uintptr(unsafe.Pointer(StringBytePtr(argv0))),
-		uintptr(unsafe.Pointer(&StringArrayPtr(argv)[0])),
+		uintptr(unsafe.Pointer(&StringSlicePtr(argv)[0])),
 		0)
 
 	return NewError(e)