syscall: add ptrace on darwin

The ptrace syscall remains gutted on darwin, but usable.  This
also makes the syscall addition process reproducible on darwin
instead of relying on a file path in rsc's home directory.
I've also removed an override of $PATH in env.bash that made
tooling harder.

R=rsc, dave, r
CC=golang-dev
https://golang.org/cl/4517147

src/pkg/syscall/mkall.sh

@@ -120,14 +120,13 @@ freebsd_amd64)
 darwin_386)
 	mkerrors="$mkerrors -f -m32"
 	mksyscall="./mksyscall.pl -l32"
-	mksysnum="./mksysnum_darwin.pl /home/rsc/pub/xnu-1228/bsd/kern/syscalls.master"
+	mksysnum="./mksysnum_darwin.pl /usr/include/sys/syscall.h"
 	mktypes="godefs -gsyscall -f-m32"
 	;;
 darwin_amd64)
 	mkerrors="$mkerrors -f -m64"
-	mksysnum="./mksysnum_darwin.pl /home/rsc/pub/xnu-1228/bsd/kern/syscalls.master"
+	mksysnum="./mksysnum_darwin.pl /usr/include/sys/syscall.h"
 	mktypes="godefs -gsyscall -f-m64"
-	mkerrors="./mkerrors.sh"
 	;;
 linux_386)
 	mkerrors="$mkerrors -f -m32"

src/pkg/syscall/mkerrors.sh

@@ -47,6 +47,7 @@ includes_Darwin='
 #define _DARWIN_USE_64_BIT_INODE
 #include <sys/types.h>
 #include <sys/event.h>
+#include <sys/ptrace.h>
 #include <sys/socket.h>
 #include <sys/sockio.h>
 #include <sys/sysctl.h>
@@ -136,7 +137,7 @@ done
 		$2 == "CTL_MAXNAME" ||
 		$2 ~ /^(MS|MNT)_/ ||
 		$2 ~ /^TUN(SET|GET|ATTACH|DETACH)/ ||
-		$2 ~ /^(O|F|FD|NAME|S|PTRACE)_/ ||
+		$2 ~ /^(O|F|FD|NAME|S|PTRACE|PT)_/ ||
 		$2 ~ /^LINUX_REBOOT_CMD_/ ||
 		$2 ~ /^LINUX_REBOOT_MAGIC[12]$/ ||
 		$2 !~ "NLA_TYPE_MASK" &&

src/pkg/syscall/mksysnum_darwin.pl

@@ -3,8 +3,7 @@
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
 #
-# Generate system call table for Darwin from master list
-# (for example, xnu-1228/bsd/kern/syscalls.master).
+# Generate system call table for Darwin from sys/syscall.h
 
 my $command = "mksysnum_darwin.pl " . join(' ', @ARGV);
 
@@ -18,18 +17,11 @@ const (
 EOF
 
 while(<>){
-	if(/^([0-9]+)\s+ALL\s+({ \S+\s+(\w+).*})/){
-		my $num = $1;
-		my $proto = $2;
-		my $name = "SYS_$3";
+	if(/^#define\s+SYS_(\w+)\s+([0-9]+)/){
+		my $name = $1;
+		my $num = $2;
 		$name =~ y/a-z/A-Z/;
-
-		# There are multiple entries for enosys and nosys, so comment them out.
-		if($name =~ /^SYS_E?NOSYS$/){
-			$name = "// $name";
-		}
-
-		print "	$name = $num;  // $proto\n";
+		print "	SYS_$name = $num;"
 	}
 }
 

src/pkg/syscall/syscall_darwin.go

@@ -56,6 +56,10 @@ func ParseDirent(buf []byte, max int, names []string) (consumed int, count int,
 	return origlen - len(buf), count, names
 }
 
+//sys   ptrace(request int, pid int, addr uintptr, data uintptr) (errno int)
+func PtraceAttach(pid int) (errno int) { return ptrace(PT_ATTACH, pid, 0, 0) }
+func PtraceDetach(pid int) (errno int) { return ptrace(PT_DETACH, pid, 0, 0) }
+
 // TODO
 func Sendfile(outfd int, infd int, offset *int64, count int) (written int, errno int) {
 	return -1, ENOSYS

src/pkg/syscall/zerrors_darwin_386.go

@@ -709,6 +709,24 @@ const (
 	PROT_NONE                   = 0
 	PROT_READ                   = 0x1
 	PROT_WRITE                  = 0x2
+	PT_ATTACH                   = 0xa
+	PT_ATTACHEXC                = 0xe
+	PT_CONTINUE                 = 0x7
+	PT_DENY_ATTACH              = 0x1f
+	PT_DETACH                   = 0xb
+	PT_FIRSTMACH                = 0x20
+	PT_FORCEQUOTA               = 0x1e
+	PT_KILL                     = 0x8
+	PT_READ_D                   = 0x2
+	PT_READ_I                   = 0x1
+	PT_READ_U                   = 0x3
+	PT_SIGEXC                   = 0xc
+	PT_STEP                     = 0x9
+	PT_THUPDATE                 = 0xd
+	PT_TRACE_ME                 = 0
+	PT_WRITE_D                  = 0x5
+	PT_WRITE_I                  = 0x4
+	PT_WRITE_U                  = 0x6
 	RTAX_AUTHOR                 = 0x6
 	RTAX_BRD                    = 0x7
 	RTAX_DST                    = 0

src/pkg/syscall/zerrors_darwin_amd64.go

-// mkerrors.sh
+// mkerrors.sh -f -m64
 // MACHINE GENERATED BY THE COMMAND ABOVE; DO NOT EDIT
 
-// godefs -c gcc -gsyscall _const.c
+// godefs -c gcc -f -m64 -gsyscall -f -m64 _const.c
 
 // MACHINE GENERATED - DO NOT EDIT.
 
@@ -709,6 +709,24 @@ const (
 	PROT_NONE                   = 0
 	PROT_READ                   = 0x1
 	PROT_WRITE                  = 0x2
+	PT_ATTACH                   = 0xa
+	PT_ATTACHEXC                = 0xe
+	PT_CONTINUE                 = 0x7
+	PT_DENY_ATTACH              = 0x1f
+	PT_DETACH                   = 0xb
+	PT_FIRSTMACH                = 0x20
+	PT_FORCEQUOTA               = 0x1e
+	PT_KILL                     = 0x8
+	PT_READ_D                   = 0x2
+	PT_READ_I                   = 0x1
+	PT_READ_U                   = 0x3
+	PT_SIGEXC                   = 0xc
+	PT_STEP                     = 0x9
+	PT_THUPDATE                 = 0xd
+	PT_TRACE_ME                 = 0
+	PT_WRITE_D                  = 0x5
+	PT_WRITE_I                  = 0x4
+	PT_WRITE_U                  = 0x6
 	RTAX_AUTHOR                 = 0x6
 	RTAX_BRD                    = 0x7
 	RTAX_DST                    = 0

src/pkg/syscall/zsyscall_darwin_386.go

@@ -219,6 +219,14 @@ func munmap(addr uintptr, length uintptr) (errno int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func ptrace(request int, pid int, addr uintptr, data uintptr) (errno int) {
+	_, _, e1 := Syscall6(SYS_PTRACE, uintptr(request), uintptr(pid), uintptr(addr), uintptr(data), 0, 0)
+	errno = int(e1)
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func kill(pid int, signum int, posix int) (errno int) {
 	_, _, e1 := Syscall(SYS_KILL, uintptr(pid), uintptr(signum), uintptr(posix))
 	errno = int(e1)

src/pkg/syscall/zsyscall_darwin_amd64.go

@@ -219,6 +219,14 @@ func munmap(addr uintptr, length uintptr) (errno int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func ptrace(request int, pid int, addr uintptr, data uintptr) (errno int) {
+	_, _, e1 := Syscall6(SYS_PTRACE, uintptr(request), uintptr(pid), uintptr(addr), uintptr(data), 0, 0)
+	errno = int(e1)
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func kill(pid int, signum int, posix int) (errno int) {
 	_, _, e1 := Syscall(SYS_KILL, uintptr(pid), uintptr(signum), uintptr(posix))
 	errno = int(e1)