[release-branch.go1.7] runtime: sleep on CLOCK_MONOTONIC in futexsleep1 on freebsd

In FreeBSD 10.0, the _umtx_op syscall was changed to allow sleeping on
any supported clock, but the default clock was switched from a monotonic
clock to CLOCK_REALTIME.

Prior to 10.0, the __umtx_op_wait* functions ignored the fourth argument
to _umtx_op (uaddr1), expected the fifth argument (uaddr2) to be a
struct timespec pointer, and used a monotonic clock (nanouptime(9)) for
timeout calculations.

Since 10.0, if callers want a clock other than CLOCK_REALTIME, they must
call _umtx_op with uaddr1 set to a value greater than sizeof(struct
timespec), and with uaddr2 as pointer to a struct _umtx_time, rather
than a timespec. Callers can set the _clockid field of the struct
_umtx_time to request the clock they want.

The relevant FreeBSD commit:
    https://svnweb.freebsd.org/base?view=revision&revision=232144

Fixes #17168

Change-Id: I3dd7b32b683622b8d7b4a6a8f9eb56401bed6bdf
Reviewed-on: https://go-review.googlesource.com/30154
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-on: https://go-review.googlesource.com/31269

diff --git a/src/runtime/defs_freebsd.go b/src/runtime/defs_freebsd.go
index 0253685aace7fc0bb8495066a491a51895a17324..3f2184d09198e1a8df6f6af70e6d5a8fd411f4fb 100644 (file)
--- a/src/runtime/defs_freebsd.go
+++ b/src/runtime/defs_freebsd.go
@@ -23,6 +23,7 @@ package runtime
 #include <sys/mman.h>
 #include <sys/ucontext.h>
 #include <sys/umtx.h>
+#include <sys/_umtx.h>
 #include <sys/rtprio.h>
 #include <sys/thr.h>
 #include <sys/_sigset.h>
@@ -49,6 +50,8 @@ const (
        SA_RESTART = C.SA_RESTART
        SA_ONSTACK = C.SA_ONSTACK
 
+       CLOCK_MONOTONIC = C.CLOCK_MONOTONIC
+
        UMTX_OP_WAIT_UINT         = C.UMTX_OP_WAIT_UINT
        UMTX_OP_WAIT_UINT_PRIVATE = C.UMTX_OP_WAIT_UINT_PRIVATE
        UMTX_OP_WAKE              = C.UMTX_OP_WAKE
@@ -130,4 +133,6 @@ type Timespec C.struct_timespec
 type Timeval C.struct_timeval
 type Itimerval C.struct_itimerval
 
+type Umtx_time C.struct__umtx_time
+
 type Kevent C.struct_kevent

diff --git a/src/runtime/defs_freebsd_386.go b/src/runtime/defs_freebsd_386.go
index 6938c18736ff65034e434ebb673cd7b161e746d3..efcbeb7a8199fbcd0a0bea6f5d724332e120f7d0 100644 (file)
--- a/src/runtime/defs_freebsd_386.go
+++ b/src/runtime/defs_freebsd_386.go
@@ -24,6 +24,8 @@ const (
        _SA_RESTART = 0x2
        _SA_ONSTACK = 0x1
 
+       _CLOCK_MONOTONIC = 0x4
+
        _UMTX_OP_WAIT_UINT         = 0xb
        _UMTX_OP_WAIT_UINT_PRIVATE = 0xf
        _UMTX_OP_WAKE              = 0x3
@@ -203,6 +205,12 @@ type itimerval struct {
        it_value    timeval
 }
 
+type umtx_time struct {
+       _timeout timespec
+       _flags   uint32
+       _clockid uint32
+}
+
 type keventt struct {
        ident  uint32
        filter int16

diff --git a/src/runtime/defs_freebsd_amd64.go b/src/runtime/defs_freebsd_amd64.go
index de98e7a3c13485bf62158819a319dd0290f2a918..594f9575874238f2ce6777a95510d438d9b59e61 100644 (file)
--- a/src/runtime/defs_freebsd_amd64.go
+++ b/src/runtime/defs_freebsd_amd64.go
@@ -24,6 +24,8 @@ const (
        _SA_RESTART = 0x2
        _SA_ONSTACK = 0x1
 
+       _CLOCK_MONOTONIC = 0x4
+
        _UMTX_OP_WAIT_UINT         = 0xb
        _UMTX_OP_WAIT_UINT_PRIVATE = 0xf
        _UMTX_OP_WAKE              = 0x3
@@ -214,6 +216,12 @@ type itimerval struct {
        it_value    timeval
 }
 
+type umtx_time struct {
+       _timeout timespec
+       _flags   uint32
+       _clockid uint32
+}
+
 type keventt struct {
        ident  uint64
        filter int16

diff --git a/src/runtime/defs_freebsd_arm.go b/src/runtime/defs_freebsd_arm.go
index 744330f4b3e2bf83e14250ea9d27a52a665f9962..0e9a2e93c5a716d49f76c271b7e08f9ef7e24bdb 100644 (file)
--- a/src/runtime/defs_freebsd_arm.go
+++ b/src/runtime/defs_freebsd_arm.go
@@ -24,6 +24,8 @@ const (
        _SA_RESTART = 0x2
        _SA_ONSTACK = 0x1
 
+       _CLOCK_MONOTONIC = 0x4
+
        _UMTX_OP_WAIT_UINT         = 0xb
        _UMTX_OP_WAIT_UINT_PRIVATE = 0xf
        _UMTX_OP_WAKE              = 0x3
@@ -176,6 +178,12 @@ type itimerval struct {
        it_value    timeval
 }
 
+type umtx_time struct {
+       _timeout timespec
+       _flags   uint32
+       _clockid uint32
+}
+
 type keventt struct {
        ident  uint32
        filter int16

diff --git a/src/runtime/os_freebsd.go b/src/runtime/os_freebsd.go
index c187ee805f68d07b246732fd37afce5fccc9df54..0e09c60ecdea6eb203e67322d3cb1ea352e4c122 100644 (file)
--- a/src/runtime/os_freebsd.go
+++ b/src/runtime/os_freebsd.go
@@ -35,7 +35,7 @@ func raise(sig int32)
 func raiseproc(sig int32)
 
 //go:noescape
-func sys_umtx_op(addr *uint32, mode int32, val uint32, ptr2, ts *timespec) int32
+func sys_umtx_op(addr *uint32, mode int32, val uint32, uaddr1 uintptr, ut *umtx_time) int32
 
 func osyield()
 
@@ -70,14 +70,14 @@ func futexsleep(addr *uint32, val uint32, ns int64) {
 }
 
 func futexsleep1(addr *uint32, val uint32, ns int64) {
-       var tsp *timespec
+       var utp *umtx_time
        if ns >= 0 {
-               var ts timespec
-               ts.tv_nsec = 0
-               ts.set_sec(int64(timediv(ns, 1000000000, (*int32)(unsafe.Pointer(&ts.tv_nsec)))))
-               tsp = &ts
+               var ut umtx_time
+               ut._clockid = _CLOCK_MONOTONIC
+               ut._timeout.set_sec(int64(timediv(ns, 1000000000, (*int32)(unsafe.Pointer(&ut._timeout.tv_nsec)))))
+               utp = &ut
        }
-       ret := sys_umtx_op(addr, _UMTX_OP_WAIT_UINT_PRIVATE, val, nil, tsp)
+       ret := sys_umtx_op(addr, _UMTX_OP_WAIT_UINT_PRIVATE, val, unsafe.Sizeof(*utp), utp)
        if ret >= 0 || ret == -_EINTR {
                return
        }
@@ -87,7 +87,7 @@ func futexsleep1(addr *uint32, val uint32, ns int64) {
 
 //go:nosplit
 func futexwakeup(addr *uint32, cnt uint32) {
-       ret := sys_umtx_op(addr, _UMTX_OP_WAKE_PRIVATE, cnt, nil, nil)
+       ret := sys_umtx_op(addr, _UMTX_OP_WAKE_PRIVATE, cnt, 0, nil)
        if ret >= 0 {
                return
        }

diff --git a/src/runtime/sys_freebsd_amd64.s b/src/runtime/sys_freebsd_amd64.s
index 9700117d0f2edf18c04205fe04871b51c9a65fa2..277e7f8b075362b2ea78c2ae63eb7240e5f47225 100644 (file)
--- a/src/runtime/sys_freebsd_amd64.s
+++ b/src/runtime/sys_freebsd_amd64.s
@@ -14,8 +14,8 @@ TEXT runtime·sys_umtx_op(SB),NOSPLIT,$0
        MOVQ addr+0(FP), DI
        MOVL mode+8(FP), SI
        MOVL val+12(FP), DX
-       MOVQ ptr2+16(FP), R10
-       MOVQ ts+24(FP), R8
+       MOVQ uaddr1+16(FP), R10
+       MOVQ ut+24(FP), R8
        MOVL $454, AX
        SYSCALL
        MOVL    AX, ret+32(FP)

diff --git a/src/runtime/sys_freebsd_arm.s b/src/runtime/sys_freebsd_arm.s
index e7dfb281d586c9e55634290904c91940a882dd01..3c5a5cbbb06c59de22f46787d48da7341d53a071 100644 (file)
--- a/src/runtime/sys_freebsd_arm.s
+++ b/src/runtime/sys_freebsd_arm.s
@@ -45,7 +45,7 @@ TEXT runtime·sys_umtx_op(SB),NOSPLIT,$0
        MOVW addr+0(FP), R0
        MOVW mode+4(FP), R1
        MOVW val+8(FP), R2
-       MOVW ptr2+12(FP), R3
+       MOVW uaddr1+12(FP), R3
        ADD $20, R13 // arg 5 is passed on stack
        MOVW $SYS__umtx_op, R7
        SWI $0