diff options
Diffstat (limited to '')
| -rw-r--r-- | lang/go14/files/patch-syscall | 48 |
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) |