[dev.typealias] all: merge go1.8.3 into dev.typealiasdev.typealias

352996a381 (tag: go1.8.3) [release-branch.go1.8] go1.8.3
bb5055d6f1 [release-branch.go1.8] doc: document go1.8.3
439c0c8be8 [release-branch.go1.8] cmd/compile: don't move spills to loop exits where the spill is dead
e396667ba3 [release-branch.go1.8] cmd/compile: zero ambiguously live variables at VARKILLs
daf6706f37 [release-branch.go1.8] runtime: use pselect6 for usleep on linux/386
958c64bbab [release-branch.go1.8] runtime: use pselect6 for usleep on linux/amd64 and linux/arm
195e20a976 [release-branch.go1.8] cmd/compile: ignore types when considering tuple select for CSE
f55bc1c4eb [release-branch.go1.8] net/http: update bundled http2 for gracefulShutdownCh lock contention slowdown
51f508bb4a [release-branch.go1.8] cmd/compile: fix s390x unsigned comparison constant merging rules
243dee1737 [release-branch.go1.8] cmd/go: if we get a C compiler dwarf2 warning, try without -g
a43c0d2dc8 [release-branch.go1.8] runtime: don't corrupt arena bounds on low mmap
1054085dcf [release-branch.go1.8] cmd/compile: fix store chain in schedule pass
18a13d373a [release-branch.go1.8] runtime: doubly fix "double wakeup" panic
6efa2f22ac [release-branch.go1.8] database/sql: ensure releaseConn is defined before a possible close
fb9770f09b [release-branch.go1.8] runtime: print debug info on "base out of range"
b6a8fc8d8c [release-branch.go1.8] doc: remove mentions of yacc tool
59870f9e19 (tag: go1.8.2) [release-branch.go1.8] go1.8.2
c9688ddb6b [release-branch.go1.8] doc: document go1.8.2 and go1.7.6
38d35f49e7 [release-branch.go1.8] crypto/elliptic: fix carry bug in x86-64 P-256 implementation.

Change-Id: I2aa0eab7a990d24e25809fb13ce6cb031104f474

6 files changed, 31 insertions, 9 deletions

diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go
index da39dac510..6f07731a49 100644
--- a/src/runtime/malloc.go
+++ b/src/runtime/malloc.go
@@ -400,10 +400,12 @@ func (h *mheap) sysAlloc(n uintptr) unsafe.Pointer {
 			if p == 0 {
 				return nil
 			}
+			// p can be just about anywhere in the address
+			// space, including before arena_end.
 			if p == h.arena_end {
 				h.arena_end = new_end
 				h.arena_reserved = reserved
-			} else if h.arena_start <= p && p+p_size-h.arena_start-1 <= _MaxArena32 {
+			} else if h.arena_end < p && p+p_size-h.arena_start-1 <= _MaxArena32 {
 				// Keep everything page-aligned.
 				// Our pages are bigger than hardware pages.
 				h.arena_end = p + p_size
@@ -413,6 +415,16 @@ func (h *mheap) sysAlloc(n uintptr) unsafe.Pointer {
 				h.arena_used = used
 				h.arena_reserved = reserved
 			} else {
+				// We got a mapping, but it's not
+				// linear with our current arena, so
+				// we can't use it.
+				//
+				// TODO: Make it possible to allocate
+				// from this. We can't decrease
+				// arena_used, but we could introduce
+				// a new variable for the current
+				// allocation position.
+
 				// We haven't added this allocation to
 				// the stats, so subtract it from a
 				// fake stat (but avoid underflow).
diff --git a/src/runtime/mbitmap.go b/src/runtime/mbitmap.go
index 89d8a4cc76..9b988fae25 100644
--- a/src/runtime/mbitmap.go
+++ b/src/runtime/mbitmap.go
@@ -374,6 +374,7 @@ func heapBitsForAddr(addr uintptr) heapBits {
 // heapBitsForSpan returns the heapBits for the span base address base.
 func heapBitsForSpan(base uintptr) (hbits heapBits) {
 	if base < mheap_.arena_start || base >= mheap_.arena_used {
+		print("runtime: base ", hex(base), " not in range [", hex(mheap_.arena_start), ",", hex(mheap_.arena_used), ")\n")
 		throw("heapBitsForSpan: base out of range")
 	}
 	return heapBitsForAddr(base)
diff --git a/src/runtime/mgc.go b/src/runtime/mgc.go
index cd57720917..8f424926cb 100644
--- a/src/runtime/mgc.go
+++ b/src/runtime/mgc.go
@@ -1918,7 +1918,7 @@ func gchelper() {
 		traceGCScanDone()
 	}
 
-	nproc := work.nproc // work.nproc can change right after we increment work.ndone
+	nproc := atomic.Load(&work.nproc) // work.nproc can change right after we increment work.ndone
 	if atomic.Xadd(&work.ndone, +1) == nproc-1 {
 		notewakeup(&work.alldone)
 	}
diff --git a/src/runtime/sys_linux_386.s b/src/runtime/sys_linux_386.s
index 45320c068a..ba6f7cc8dd 100644
--- a/src/runtime/sys_linux_386.s
+++ b/src/runtime/sys_linux_386.s
@@ -98,15 +98,18 @@ TEXT runtime·usleep(SB),NOSPLIT,$8
 	MOVL	$1000000, CX
 	DIVL	CX
 	MOVL	AX, 0(SP)
+	MOVL	$1000, AX	// usec to nsec
+	MULL	DX
 	MOVL	DX, 4(SP)
 
-	// select(0, 0, 0, 0, &tv)
-	MOVL	$142, AX
+	// pselect6(0, 0, 0, 0, &ts, 0)
+	MOVL	$308, AX
 	MOVL	$0, BX
 	MOVL	$0, CX
 	MOVL	$0, DX
 	MOVL	$0, SI
 	LEAL	0(SP), DI
+	MOVL	$0, BP
 	INVOKE_SYSCALL
 	RET
 
diff --git a/src/runtime/sys_linux_amd64.s b/src/runtime/sys_linux_amd64.s
index 6ddcb30ae2..8ab8d12d0f 100644
--- a/src/runtime/sys_linux_amd64.s
+++ b/src/runtime/sys_linux_amd64.s
@@ -82,15 +82,18 @@ TEXT runtime·usleep(SB),NOSPLIT,$16
 	MOVL	$1000000, CX
 	DIVL	CX
 	MOVQ	AX, 0(SP)
-	MOVQ	DX, 8(SP)
+	MOVL	$1000, AX	// usec to nsec
+	MULL	DX
+	MOVQ	AX, 8(SP)
 
-	// select(0, 0, 0, 0, &tv)
+	// pselect6(0, 0, 0, 0, &ts, 0)
 	MOVL	$0, DI
 	MOVL	$0, SI
 	MOVL	$0, DX
 	MOVL	$0, R10
 	MOVQ	SP, R8
-	MOVL	$23, AX
+	MOVL	$0, R9
+	MOVL	$270, AX
 	SYSCALL
 	RET
 
diff --git a/src/runtime/sys_linux_arm.s b/src/runtime/sys_linux_arm.s
index 666b879f02..f21a351c05 100644
--- a/src/runtime/sys_linux_arm.s
+++ b/src/runtime/sys_linux_arm.s
@@ -36,7 +36,7 @@
 #define SYS_gettid (SYS_BASE + 224)
 #define SYS_tkill (SYS_BASE + 238)
 #define SYS_sched_yield (SYS_BASE + 158)
-#define SYS_select (SYS_BASE + 142) // newselect
+#define SYS_pselect6 (SYS_BASE + 335)
 #define SYS_ugetrlimit (SYS_BASE + 191)
 #define SYS_sched_getaffinity (SYS_BASE + 242)
 #define SYS_clock_gettime (SYS_BASE + 263)
@@ -387,13 +387,16 @@ TEXT runtime·usleep(SB),NOSPLIT,$12
 	MOVW	usec+0(FP), R0
 	CALL	runtime·usplitR0(SB)
 	MOVW	R0, 4(R13)
+	MOVW	$1000, R0	// usec to nsec
+	MUL	R0, R1
 	MOVW	R1, 8(R13)
 	MOVW	$0, R0
 	MOVW	$0, R1
 	MOVW	$0, R2
 	MOVW	$0, R3
 	MOVW	$4(R13), R4
-	MOVW	$SYS_select, R7
+	MOVW	$0, R5
+	MOVW	$SYS_pselect6, R7
 	SWI	$0
 	RET