runtime: fix vet complaints for linux/amd64

Working toward making the tree vet-safe instead of having
so many exceptions in cmd/vet/all/whitelist.

This CL makes "GOOS=linux GOARCH=amd64 go vet -unsafeptr=false runtime" happy,
while keeping "GO_BUILDER_NAME=misc-vetall go tool dist test" happy too.

For #31916.

Change-Id: I4ca1acb02f4666b102d25fcc55fac96b8f80379a
Reviewed-on: https://go-review.googlesource.com/c/go/+/176100
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

src/cmd/vet/all/whitelist/amd64.txt

-// amd64-specific vet whitelist. See readme.txt for details.
-
-// False positives.
-
-// reflect trampolines intentionally omit arg size. Same for morestack.
-runtime/asm_amd64.s: [amd64] morestack: use of 8(SP) points beyond argument frame
-runtime/asm_amd64.s: [amd64] morestack: use of 16(SP) points beyond argument frame
-runtime/asm_amd64.s: [amd64] morestack: use of 8(SP) points beyond argument frame
-
-// Intentionally missing declarations. These are special assembly routines.
-// Some are jumped into from other routines, with values in specific registers.
-// duff* have direct calls from the compiler.
-// Others use the platform ABI.
-// There is no sensible corresponding Go prototype.
-runtime/asm_amd64.s: [amd64] aeshashbody: function aeshashbody missing Go declaration

src/cmd/vet/all/whitelist/android_amd64.txt

-// android/amd64-specific vet whitelist. See readme.txt for details.
-
-runtime/sys_linux_amd64.s: [amd64] settls: function settls missing Go declaration

src/cmd/vet/all/whitelist/darwin_amd64.txt

-// darwin/amd64-specific vet whitelist. See readme.txt for details.
-
-runtime/sys_darwin_amd64.s: [amd64] settls: function settls missing Go declaration

src/cmd/vet/all/whitelist/dragonfly_amd64.txt

 // dragonfly/amd64-specific vet whitelist. See readme.txt for details.
 
-runtime/sys_dragonfly_amd64.s: [amd64] settls: function settls missing Go declaration
 
 syscall/asm9_unix2_amd64.s: [amd64] Syscall9: 8(SP) should be num+0(FP)
 syscall/asm9_unix2_amd64.s: [amd64] Syscall9: 16(SP) should be a1+8(FP)

src/cmd/vet/all/whitelist/freebsd_amd64.txt

 // freebsd/amd64-specific vet whitelist. See readme.txt for details.
 
-runtime/sys_freebsd_amd64.s: [amd64] settls: function settls missing Go declaration
 syscall/asm9_unix2_amd64.s: [amd64] Syscall9: 8(SP) should be num+0(FP)
 syscall/asm9_unix2_amd64.s: [amd64] Syscall9: 16(SP) should be a1+8(FP)
 syscall/asm9_unix2_amd64.s: [amd64] Syscall9: 24(SP) should be a2+16(FP)

src/cmd/vet/all/whitelist/illumos_amd64.txt

 // illumos/amd64-specific vet whitelist. See readme.txt for details.
 
-runtime/sys_solaris_amd64.s: [amd64] settls: function settls missing Go declaration
 runtime/sys_solaris_amd64.s: [amd64] pipe1: function pipe1 missing Go declaration
 runtime/sys_solaris_amd64.s: [amd64] asmsysvicall6: function asmsysvicall6 missing Go declaration
 runtime/sys_solaris_amd64.s: [amd64] usleep2: function usleep2 missing Go declaration

src/cmd/vet/all/whitelist/linux_amd64.txt

-// linux/amd64-specific vet whitelist. See readme.txt for details.
-
-runtime/sys_linux_amd64.s: [amd64] settls: function settls missing Go declaration

src/cmd/vet/all/whitelist/nacl_amd64p32.txt

@@ -10,7 +10,6 @@ runtime/sys_nacl_amd64p32.s: [amd64p32] sigtramp: unknown variable ctxt
 runtime/sys_nacl_amd64p32.s: [amd64p32] sigtramp: unknown variable ctxt
 runtime/sys_nacl_amd64p32.s: [amd64p32] nacl_sysinfo: function nacl_sysinfo missing Go declaration
 runtime/sys_nacl_amd64p32.s: [amd64p32] nacl_clock_gettime: function nacl_clock_gettime missing Go declaration
-runtime/sys_nacl_amd64p32.s: [amd64p32] settls: function settls missing Go declaration
 
 // Clearer using FP than SP, but that requires named offsets.
 runtime/asm_amd64p32.s: [amd64p32] rt0_go: unknown variable argc

src/cmd/vet/all/whitelist/netbsd_386.txt

 // netbsd/386-specific vet whitelist. See readme.txt for details.
 
-runtime/sys_netbsd_ARCHSUFF.s: [GOARCH] settls: function settls missing Go declaration
-runtime/sys_netbsd_ARCHSUFF.s: [GOARCH] sigreturn_tramp: function sigreturn_tramp missing Go declaration
-
 runtime/sys_netbsd_386.s: [386] sigreturn_tramp: use of 140(SP) points beyond argument frame
 runtime/sys_netbsd_386.s: [386] sigreturn_tramp: use of 4(SP) points beyond argument frame
 runtime/sys_netbsd_386.s: [386] sigreturn_tramp: use of 4(SP) points beyond argument frame

src/cmd/vet/all/whitelist/netbsd_amd64.txt

-// netbsd/amd64-specific vet whitelist. See readme.txt for details.
-
-runtime/sys_netbsd_ARCHSUFF.s: [GOARCH] sigreturn_tramp: function sigreturn_tramp missing Go declaration
-
-runtime/sys_netbsd_amd64.s: [amd64] settls: function settls missing Go declaration

src/cmd/vet/all/whitelist/openbsd_386.txt

@@ -3,7 +3,6 @@
 runtime/sys_openbsd_386.s: [386] sigtramp: unknown variable signo
 runtime/sys_openbsd_386.s: [386] sigtramp: unknown variable info
 runtime/sys_openbsd_386.s: [386] sigtramp: unknown variable context
-runtime/sys_openbsd_386.s: [386] settls: function settls missing Go declaration
 syscall/asm_unix_386.s: [386] Syscall: 8(SP) should be a1+4(FP)
 syscall/asm_unix_386.s: [386] Syscall: 4(SP) should be trap+0(FP)
 syscall/asm_unix_386.s: [386] Syscall6: 8(SP) should be a1+4(FP)

src/cmd/vet/all/whitelist/openbsd_amd64.txt

-// openbsd/amd64-specific vet whitelist. See readme.txt for details.
-
-runtime/sys_openbsd_amd64.s: [amd64] settls: function settls missing Go declaration

src/cmd/vet/all/whitelist/plan9_amd64.txt

-// plan9/amd64-specific vet whitelist. See readme.txt for details.
-
-runtime/sys_plan9_amd64.s: [amd64] settls: function settls missing Go declaration

src/cmd/vet/all/whitelist/solaris_amd64.txt

 // solaris/amd64-specific vet whitelist. See readme.txt for details.
 
-runtime/sys_solaris_amd64.s: [amd64] settls: function settls missing Go declaration
 runtime/sys_solaris_amd64.s: [amd64] pipe1: function pipe1 missing Go declaration
 runtime/sys_solaris_amd64.s: [amd64] asmsysvicall6: function asmsysvicall6 missing Go declaration
 runtime/sys_solaris_amd64.s: [amd64] usleep2: function usleep2 missing Go declaration

src/cmd/vet/all/whitelist/windows_amd64.txt

@@ -3,4 +3,3 @@
 runtime/sys_windows_amd64.s: [amd64] ctrlhandler: RET without writing to 4-byte ret+8(FP)
 runtime/sys_windows_amd64.s: [amd64] callbackasm1: function callbackasm1 missing Go declaration
 runtime/sys_windows_amd64.s: [amd64] tstart_stdcall: RET without writing to 4-byte ret+8(FP)
-runtime/sys_windows_amd64.s: [amd64] settls: function settls missing Go declaration

src/runtime/asm_amd64.s

@@ -424,6 +424,7 @@ TEXT runtime·morestack(SB),NOSPLIT,$0-0
 
 	// Called from f.
 	// Set m->morebuf to f's caller.
+	NOP	SP	// tell vet SP changed - stop checking offsets
 	MOVQ	8(SP), AX	// f's caller's PC
 	MOVQ	AX, (m_morebuf+gobuf_pc)(BX)
 	LEAQ	16(SP), AX	// f's caller's SP
@@ -890,7 +891,7 @@ TEXT runtime·aeshash(SB),NOSPLIT,$0-32
 	MOVQ	p+0(FP), AX	// ptr to data
 	MOVQ	s+16(FP), CX	// size
 	LEAQ	ret+24(FP), DX
-	JMP	runtime·aeshashbody(SB)
+	JMP	aeshashbody<>(SB)
 
 // func aeshashstr(p unsafe.Pointer, h uintptr) uintptr
 TEXT runtime·aeshashstr(SB),NOSPLIT,$0-24
@@ -898,12 +899,12 @@ TEXT runtime·aeshashstr(SB),NOSPLIT,$0-24
 	MOVQ	8(AX), CX	// length of string
 	MOVQ	(AX), AX	// string data
 	LEAQ	ret+16(FP), DX
-	JMP	runtime·aeshashbody(SB)
+	JMP	aeshashbody<>(SB)
 
 // AX: data
 // CX: length
 // DX: address to put return value
-TEXT runtime·aeshashbody(SB),NOSPLIT,$0-0
+TEXT aeshashbody<>(SB),NOSPLIT,$0-0
 	// Fill an SSE register with our seeds.
 	MOVQ	h+8(FP), X0			// 64 bits of per-table hash seed
 	PINSRW	$4, CX, X0			// 16 bits of length

src/runtime/stubs_386.go

@@ -9,6 +9,9 @@ import "unsafe"
 func float64touint32(a float64) uint32
 func uint32tofloat64(a uint32) float64
 
+// stackcheck checks that SP is in range [g->stack.lo, g->stack.hi).
+func stackcheck()
+
 // Called from assembly only; declared for go vet.
 func setldt(slot uintptr, base unsafe.Pointer, size uintptr)
 func emptyfunc()

src/runtime/stubs_x86.go → src/runtime/stubs_amd64x.go

@@ -2,9 +2,12 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build amd64 amd64p32 386
+// +build amd64 amd64p32
 
 package runtime
 
 // stackcheck checks that SP is in range [g->stack.lo, g->stack.hi).
 func stackcheck()
+
+// Called from assembly only; declared for go vet.
+func settls() // argument in DI

src/runtime/sys_netbsd_386.s

@@ -324,7 +324,7 @@ TEXT runtime·lwp_tramp(SB),NOSPLIT,$0
 	LEAL	m_tls(BX), BP
 	PUSHAL				// save registers
 	PUSHL	BP
-	CALL	runtime·settls(SB)
+	CALL	lwp_setprivate<>(SB)
 	POPL	AX
 	POPAL
 
@@ -363,10 +363,10 @@ TEXT runtime·setldt(SB),NOSPLIT,$8
 	// Under NetBSD we set the GS base instead of messing with the LDT.
 	MOVL	base+4(FP), AX
 	MOVL	AX, 0(SP)
-	CALL	runtime·settls(SB)
+	CALL	lwp_setprivate<>(SB)
 	RET
 
-TEXT runtime·settls(SB),NOSPLIT,$16
+TEXT lwp_setprivate<>(SB),NOSPLIT,$16
 	// adjust for ELF: wants to use -4(GS) for g
 	MOVL	base+0(FP), CX
 	ADDL	$4, CX

src/runtime/sys_openbsd_386.s

@@ -292,7 +292,7 @@ TEXT runtime·tfork(SB),NOSPLIT,$12
 	LEAL	m_tls(BX), BP
 	PUSHAL				// save registers
 	PUSHL	BP
-	CALL	runtime·settls(SB)
+	CALL	set_tcb<>(SB)
 	POPL	AX
 	POPAL
 
@@ -331,10 +331,10 @@ TEXT runtime·setldt(SB),NOSPLIT,$4
 	// Under OpenBSD we set the GS base instead of messing with the LDT.
 	MOVL	base+4(FP), AX
 	MOVL	AX, 0(SP)
-	CALL	runtime·settls(SB)
+	CALL	set_tcb<>(SB)
 	RET
 
-TEXT runtime·settls(SB),NOSPLIT,$8
+TEXT set_tcb<>(SB),NOSPLIT,$8
 	// adjust for ELF: wants to use -4(GS) for g
 	MOVL	tlsbase+0(FP), CX
 	ADDL	$4, CX