Add two patches to lang/go14.

- patch-syscall

  Use SYSCALL assembly instead of INT 0x80 for syscalls on amd64.
  Using INT 0x80 as syscall gate on amd64 is an accidential and
  undocumented feature of COMPAT_FREEBSD32. It allows to use 64-bit
  ABI, but run syscalls through i386 gate.
  Go used this "feature" to workaround a bug in FreeBSD 8, which is no
  longer relevant.
  The patch is exact e9ce76b0eca8fa95dddb90b0a72aadab58de2ffc from go
  repo.
  Now lang/go14 doesn't need COMPAT_FREEBSD32 to build and run.

- patch-pipe2

  The pipe2 syscall is present in all supported versions of FreeBSD,
  but pipe was removed from FreeBSD 11. With the patch go14 can be
  built and run on a system without COMPAT_FREEBSD10.

Reviewed by:	jlaffaye

1 files changed, 48 insertions, 0 deletions

diff --git a/lang/go14/files/patch-syscall b/lang/go14/files/patch-syscall
new file mode 100644
index 000000000000..1d384d2c7553
--- /dev/null
+++ b/lang/go14/files/patch-syscall
@@ -0,0 +1,48 @@
+--- src/runtime/sys_freebsd_amd64.s.orig	2017-03-17 20:08:29.000000000 +0000
++++ src/runtime/sys_freebsd_amd64.s	2017-03-17 20:08:29.000000000 +0000
+@@ -9,31 +9,6 @@
+ #include "zasm_GOOS_GOARCH.h"
+ #include "textflag.h"
+ 
+-// FreeBSD 8, FreeBSD 9, and older versions that I have checked
+-// do not restore R10 on exit from a "restarted" system call
+-// if you use the SYSCALL instruction. This means that, for example,
+-// if a signal arrives while the wait4 system call is executing,
+-// the wait4 internally returns ERESTART, which makes the kernel
+-// back up the PC to execute the SYSCALL instruction a second time.
+-// However, since the kernel does not restore R10, the fourth
+-// argument to the system call has been lost. (FreeBSD 9 also fails
+-// to restore the fifth and sixth arguments, R8 and R9, although
+-// some earlier versions did restore those correctly.)
+-// The broken code is in fast_syscall in FreeBSD's amd64/amd64/exception.S.
+-// It restores only DI, SI, DX, AX, and RFLAGS on system call return.
+-// http://fxr.watson.org/fxr/source/amd64/amd64/exception.S?v=FREEBSD91#L399
+-//
+-// The INT $0x80 system call path (int0x80_syscall in FreeBSD's 
+-// amd64/ia32/ia32_exception.S) does not have this problem,
+-// but it expects the third argument in R10. Instead of rewriting
+-// all the assembly in this file, #define SYSCALL to a safe simulation
+-// using INT $0x80.
+-//
+-// INT $0x80 is a little slower than SYSCALL, but correctness wins.
+-//
+-// See golang.org/issue/6372.
+-#define SYSCALL MOVQ R10, CX; INT $0x80
+-	
+ TEXT runtime·sys_umtx_op(SB),NOSPLIT,$0
+ 	MOVQ addr+0(FP), DI
+ 	MOVL mode+8(FP), SI
+--- src/syscall/asm_freebsd_amd64.s.orig	2017-03-17 20:20:07.000000000 +0000
++++ src/syscall/asm_freebsd_amd64.s	2017-03-17 20:20:07.000000000 +0000
+@@ -12,11 +12,6 @@
+ // System call support for AMD64, FreeBSD
+ //
+ 
+-// The SYSCALL variant for invoking system calls is broken in FreeBSD.
+-// See comment at top of ../runtime/sys_freebsd_amd64.c and
+-// golang.org/issue/6372.
+-#define SYSCALL MOVQ R10, CX; INT $0x80
+-
+ // func Syscall(trap int64, a1, a2, a3 int64) (r1, r2, err int64);
+ // func Syscall6(trap int64, a1, a2, a3, a4, a5, a6 int64) (r1, r2, err int64);
+ // func Syscall9(trap int64, a1, a2, a3, a4, a5, a6, a7, a8, a9 int64) (r1, r2, err int64)