diff options
| author | Cherry Zhang <cherryyz@google.com> | 2020-02-25 20:30:37 -0500 |
|---|---|---|
| committer | Carlos Amedee <carlos@golang.org> | 2020-03-02 22:30:16 +0000 |
| commit | c54e36905b394dea9fbcf816c3a6e6751187258d (patch) | |
| tree | 7705b9558a592f51dd7cfcae6c33f0638e7a9a3d | |
| parent | 329317472fd3fbc3179523bd70e03e452c829846 (diff) | |
| download | go-c54e36905b394dea9fbcf816c3a6e6751187258d.tar.gz go-c54e36905b394dea9fbcf816c3a6e6751187258d.zip | |
[release-branch.go1.14] runtime: guard VZEROUPPER on CPU feature
In CL 219131 we inserted a VZEROUPPER instruction on darwin/amd64.
The instruction is not available on pre-AVX machines. Guard it
with CPU feature.
Updates #37459.
Fixes #37478.
Change-Id: I9a064df277d091be4ee594eda5c7fd8ee323102b
Reviewed-on: https://go-review.googlesource.com/c/go/+/221057
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
(cherry picked from commit c46ffdd2eca339918ed30b6ba9d4715ba769d35d)
Reviewed-on: https://go-review.googlesource.com/c/go/+/221058
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
| -rw-r--r-- | src/runtime/cpuflags.go | 1 | ||||
| -rw-r--r-- | src/runtime/mkpreempt.go | 19 | ||||
| -rw-r--r-- | src/runtime/preempt_amd64.s | 8 |
3 files changed, 17 insertions, 11 deletions
diff --git a/src/runtime/cpuflags.go b/src/runtime/cpuflags.go index 94f9331d15..4bd894d984 100644 --- a/src/runtime/cpuflags.go +++ b/src/runtime/cpuflags.go @@ -11,6 +11,7 @@ import ( // Offsets into internal/cpu records for use in assembly. const ( + offsetX86HasAVX = unsafe.Offsetof(cpu.X86.HasAVX) offsetX86HasAVX2 = unsafe.Offsetof(cpu.X86.HasAVX2) offsetX86HasERMS = unsafe.Offsetof(cpu.X86.HasERMS) offsetX86HasSSE2 = unsafe.Offsetof(cpu.X86.HasSSE2) diff --git a/src/runtime/mkpreempt.go b/src/runtime/mkpreempt.go index 31b6f5cbac..c26406e55f 100644 --- a/src/runtime/mkpreempt.go +++ b/src/runtime/mkpreempt.go @@ -244,23 +244,26 @@ func genAMD64() { // TODO: MXCSR register? + p("PUSHQ BP") + p("MOVQ SP, BP") + p("// Save flags before clobbering them") + p("PUSHFQ") + p("// obj doesn't understand ADD/SUB on SP, but does understand ADJSP") + p("ADJSP $%d", l.stack) + p("// But vet doesn't know ADJSP, so suppress vet stack checking") + p("NOP SP") + // Apparently, the signal handling code path in darwin kernel leaves // the upper bits of Y registers in a dirty state, which causes // many SSE operations (128-bit and narrower) become much slower. // Clear the upper bits to get to a clean state. See issue #37174. // It is safe here as Go code don't use the upper bits of Y registers. p("#ifdef GOOS_darwin") + p("CMPB internal∕cpu·X86+const_offsetX86HasAVX(SB), $0") + p("JE 2(PC)") p("VZEROUPPER") p("#endif") - p("PUSHQ BP") - p("MOVQ SP, BP") - p("// Save flags before clobbering them") - p("PUSHFQ") - p("// obj doesn't understand ADD/SUB on SP, but does understand ADJSP") - p("ADJSP $%d", l.stack) - p("// But vet doesn't know ADJSP, so suppress vet stack checking") - p("NOP SP") l.save() p("CALL ·asyncPreempt2(SB)") l.restore() diff --git a/src/runtime/preempt_amd64.s b/src/runtime/preempt_amd64.s index 0f2fd7d8dd..4765e9f448 100644 --- a/src/runtime/preempt_amd64.s +++ b/src/runtime/preempt_amd64.s @@ -4,9 +4,6 @@ #include "textflag.h" TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0 - #ifdef GOOS_darwin - VZEROUPPER - #endif PUSHQ BP MOVQ SP, BP // Save flags before clobbering them @@ -15,6 +12,11 @@ TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0 ADJSP $368 // But vet doesn't know ADJSP, so suppress vet stack checking NOP SP + #ifdef GOOS_darwin + CMPB internal∕cpu·X86+const_offsetX86HasAVX(SB), $0 + JE 2(PC) + VZEROUPPER + #endif MOVQ AX, 0(SP) MOVQ CX, 8(SP) MOVQ DX, 16(SP) |