[release-branch.go1.7] runtime: fix nanotime for macOS Sierra
In the beta version of the macOS Sierra (10.12) release, the
gettimeofday system call changed on x86. Previously it always returned
the time in the AX/DX registers. Now, if AX is returned as 0, it means
that the system call has stored the values into the memory pointed to by
the first argument, just as the libc gettimeofday function does. The
libc function handles both cases, and we need to do so as well.
Fixes #16272.
Change-Id: Ibe5ad50a2c5b125e92b5a4e787db4b5179f6b723
Reviewed-on: https://go-review.googlesource.com/24812
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-on: https://go-review.googlesource.com/24755
Reviewed-by: Chris Broadfoot <cbro@golang.org>
diff --git a/src/runtime/sys_darwin_386.s b/src/runtime/sys_darwin_386.s
index 9e45f8a..83f4709 100644
--- a/src/runtime/sys_darwin_386.s
+++ b/src/runtime/sys_darwin_386.s
@@ -201,6 +201,11 @@
MOVL $0, 8(SP) // time zone pointer
MOVL $116, AX
INT $0x80
+ CMPL AX, $0
+ JNE inreg
+ MOVL 12(SP), AX
+ MOVL 16(SP), DX
+inreg:
// sec is in AX, usec in DX
// convert to DX:AX nsec
MOVL DX, BX
diff --git a/src/runtime/sys_darwin_amd64.s b/src/runtime/sys_darwin_amd64.s
index 7b9cf6a..e09b906 100644
--- a/src/runtime/sys_darwin_amd64.s
+++ b/src/runtime/sys_darwin_amd64.s
@@ -155,10 +155,15 @@
systime:
// Fall back to system call (usually first call in this thread).
- MOVQ SP, DI // must be non-nil, unused
+ MOVQ SP, DI
MOVQ $0, SI
MOVL $(0x2000000+116), AX
SYSCALL
+ CMPQ AX, $0
+ JNE inreg
+ MOVQ 0(SP), AX
+ MOVL 8(SP), DX
+inreg:
// sec is in AX, usec in DX
// return nsec in AX
IMULQ $1000000000, AX
