runtime: fix vet complaints for linux/arm64, linux/mips*, linux/ppc64*, linux/s390x

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

This CL makes "go vet -unsafeptr=false runtime" happy for these GOOS/GOARCHes,
except for an unresolved complaint on mips/mipsle that is a bug in vet,
while keeping "GO_BUILDER_NAME=misc-vetall go tool dist test" happy too.

For #31916.

Change-Id: I6ef7e982a2fdbbfbc22cee876ca37ac54d8109e5
Reviewed-on: https://go-review.googlesource.com/c/go/+/176102
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

src/cmd/vet/all/whitelist/aix_ppc64.txt

-// aix/ppc64-specific vet whitelist. See readme.txt for details.
-
-runtime/asm_ppc64x.s: [ppc64] sigreturn: function sigreturn missing Go declaration
-runtime/sys_aix_ppc64.s: [ppc64] _asmsyscall6: function _asmsyscall6 missing Go declaration
-runtime/sys_aix_ppc64.s: [ppc64] _tstart: function _tstart missing Go declaration

src/cmd/vet/all/whitelist/arm64.txt

-// arm64-specific vet whitelist. See readme.txt for details.
-
-// Intentionally missing declarations.
-runtime/tls_arm64.s: [arm64] load_g: function load_g missing Go declaration
-runtime/tls_arm64.s: [arm64] save_g: function save_g missing Go declaration

src/cmd/vet/all/whitelist/linux_ppc64x.txt

-// linux/ppc64-specific vet whitelist. See readme.txt for details.
-
-runtime/sys_linux_ppc64x.s: [GOARCH] _sigtramp: function _sigtramp missing Go declaration
-runtime/sys_linux_ppc64x.s: [GOARCH] _cgoSigtramp: function _cgoSigtramp missing Go declaration

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

-// mips-specific (big endian) vet whitelist. See readme.txt for details.
-
-// Work around if-def'd code. Will be fixed by golang.org/issue/17544.
-runtime/sys_linux_mipsx.s: [mips] walltime: invalid offset sec_lo+0(FP); expected sec_lo+4(FP)
-runtime/sys_linux_mipsx.s: [mips] walltime: invalid offset sec_hi+4(FP); expected sec_hi+0(FP)
-runtime/sys_linux_mipsx.s: [mips] nanotime: invalid offset ret_lo+0(FP); expected ret_lo+4(FP)
-runtime/sys_linux_mipsx.s: [mips] nanotime: invalid offset ret_hi+4(FP); expected ret_hi+0(FP)

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

-// mipsle-specific vet whitelist. See readme.txt for details.
-
-// Work around if-def'd code. Will be fixed by golang.org/issue/17544.
-runtime/sys_linux_mipsx.s: [mipsle] walltime: invalid offset sec_lo+4(FP); expected sec_lo+0(FP)
-runtime/sys_linux_mipsx.s: [mipsle] walltime: invalid offset sec_hi+0(FP); expected sec_hi+4(FP)
-runtime/sys_linux_mipsx.s: [mipsle] nanotime: invalid offset ret_lo+4(FP); expected ret_lo+0(FP)
-runtime/sys_linux_mipsx.s: [mipsle] nanotime: invalid offset ret_hi+0(FP); expected ret_hi+4(FP)

src/runtime/asm_ppc64x.s

@@ -886,9 +886,6 @@ TEXT runtime·goexit(SB),NOSPLIT|NOFRAME|TOPFRAME,$0-0
 	// traceback from goexit1 must hit code range of goexit
 	MOVD	R0, R0	// NOP
 
-TEXT runtime·sigreturn(SB),NOSPLIT,$0-0
-	RET
-
 // prepGoExitFrame saves the current TOC pointer (i.e. the TOC pointer for the
 // module containing runtime) to the frame that goexit will execute in when
 // the goroutine exits. It's implemented in assembly mainly because that's the

src/runtime/asm_s390x.s

@@ -781,9 +781,6 @@ TEXT runtime·goexit(SB),NOSPLIT|NOFRAME|TOPFRAME,$0-0
 	// traceback from goexit1 must hit code range of goexit
 	BYTE $0x07; BYTE $0x00; // 2-byte nop
 
-TEXT runtime·sigreturn(SB),NOSPLIT,$0-0
-	RET
-
 TEXT ·publicationBarrier(SB),NOSPLIT|NOFRAME,$0-0
         // Stores are already ordered on s390x, so this is just a
         // compile barrier.

src/runtime/memclr_s390x.s

@@ -110,12 +110,12 @@ clearmt32:
 clearlt256:
 	CMPBEQ	R5, $0, done
 	ADD	$-1, R5
-	EXRL	$runtime·memclr_s390x_exrl_xc(SB), R5
+	EXRL	$memclr_exrl_xc<>(SB), R5
 done:
 	RET
 
 // DO NOT CALL - target for exrl (execute relative long) instruction.
-TEXT runtime·memclr_s390x_exrl_xc(SB),NOSPLIT|NOFRAME,$0-0
+TEXT memclr_exrl_xc<>(SB),NOSPLIT|NOFRAME,$0-0
 	XC	$1, 0(R4), 0(R4)
 	MOVD	$0, 0(R0)
 	RET

src/runtime/memmove_s390x.s

@@ -66,7 +66,7 @@ forwards_fast:
 forwards_small:
 	CMPBEQ	R5, $0, done
 	ADD	$-1, R5
-	EXRL	$runtime·memmove_s390x_exrl_mvc(SB), R5
+	EXRL	$memmove_exrl_mvc<>(SB), R5
 	RET
 
 move0to3:
@@ -182,7 +182,7 @@ done:
 	RET
 
 // DO NOT CALL - target for exrl (execute relative long) instruction.
-TEXT runtime·memmove_s390x_exrl_mvc(SB),NOSPLIT|NOFRAME,$0-0
+TEXT memmove_exrl_mvc<>(SB),NOSPLIT|NOFRAME,$0-0
 	MVC	$1, 0(R4), 0(R6)
 	MOVD	R0, 0(R0)
 	RET

src/runtime/stubs_arm64.go

+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package runtime
+
+// Called from assembly only; declared for go vet.
+func load_g()
+func save_g()

src/runtime/stubs_mips64x.go

+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build mips64 mips64le
+
+package runtime
+
+// Called from assembly only; declared for go vet.
+func load_g()
+func save_g()

src/runtime/stubs_mipsx.go

+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build mips mipsle
+
+package runtime
+
+// Called from assembly only; declared for go vet.
+func load_g()
+func save_g()

src/runtime/stubs_ppc64x.go

+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ppc64 ppc64le
+
+package runtime
+
+// Called from assembly only; declared for go vet.
+func load_g()
+func save_g()
+func reginit()

src/runtime/stubs_s390x.go

+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package runtime
+
+// Called from assembly only; declared for go vet.
+func load_g()
+func save_g()

src/runtime/sys_aix_ppc64.s

@@ -15,7 +15,7 @@
 #include "asm_ppc64x.h"
 
 // This function calls a C function with the function descriptor in R12
-TEXT runtime·callCfunction(SB),	NOSPLIT|NOFRAME,$0
+TEXT callCfunction<>(SB),	NOSPLIT|NOFRAME,$0
 	MOVD	0(R12), R12
 	MOVD	R2, 40(R1)
 	MOVD	0(R12), R0
@@ -31,12 +31,12 @@ TEXT runtime·callCfunction(SB),	NOSPLIT|NOFRAME,$0
 // It reserves a stack of 288 bytes for the C function.
 // NOT USING GO CALLING CONVENTION
 // runtime.asmsyscall6 is a function descriptor to the real asmsyscall6.
-DATA	runtime·asmsyscall6+0(SB)/8, $runtime·_asmsyscall6(SB)
+DATA	runtime·asmsyscall6+0(SB)/8, $asmsyscall6<>(SB)
 DATA	runtime·asmsyscall6+8(SB)/8, $TOC(SB)
 DATA	runtime·asmsyscall6+16(SB)/8, $0
 GLOBL	runtime·asmsyscall6(SB), NOPTR, $24
 
-TEXT runtime·_asmsyscall6(SB),NOSPLIT,$256
+TEXT asmsyscall6<>(SB),NOSPLIT,$256
 	MOVD	R3, 48(R1) // Save libcall for later
 	MOVD	libcall_fn(R3), R12
 	MOVD	libcall_args(R3), R9
@@ -46,7 +46,7 @@ TEXT runtime·_asmsyscall6(SB),NOSPLIT,$256
 	MOVD	24(R9), R6
 	MOVD	32(R9), R7
 	MOVD	40(R9), R8
-	BL	runtime·callCfunction(SB)
+	BL	callCfunction<>(SB)
 
 	// Restore R0 and TOC
 	XOR	R0, R0
@@ -90,15 +90,15 @@ TEXT runtime·sigfwd(SB),NOSPLIT,$0-32
 
 
 // runtime.sigtramp is a function descriptor to the real sigtramp.
-DATA	runtime·sigtramp+0(SB)/8, $runtime·_sigtramp(SB)
+DATA	runtime·sigtramp+0(SB)/8, $sigtramp<>(SB)
 DATA	runtime·sigtramp+8(SB)/8, $TOC(SB)
 DATA	runtime·sigtramp+16(SB)/8, $0
 GLOBL	runtime·sigtramp(SB), NOPTR, $24
 
-// This funcion must not have any frame as we want to control how
+// This function must not have any frame as we want to control how
 // every registers are used.
 // TODO(aix): Implement SetCgoTraceback handler.
-TEXT runtime·_sigtramp(SB),NOSPLIT|NOFRAME,$0
+TEXT sigtramp<>(SB),NOSPLIT|NOFRAME,$0
 	MOVD	LR, R0
 	MOVD	R0, 16(R1)
 	// initialize essential registers (just in case)
@@ -189,12 +189,12 @@ exit:
 	BR (LR)
 
 // runtime.tstart is a function descriptor to the real tstart.
-DATA	runtime·tstart+0(SB)/8, $runtime·_tstart(SB)
+DATA	runtime·tstart+0(SB)/8, $tstart<>(SB)
 DATA	runtime·tstart+8(SB)/8, $TOC(SB)
 DATA	runtime·tstart+16(SB)/8, $0
 GLOBL	runtime·tstart(SB), NOPTR, $24
 
-TEXT runtime·_tstart(SB),NOSPLIT,$0
+TEXT tstart<>(SB),NOSPLIT,$0
 	XOR	 R0, R0 // reset R0
 
 	// set g

src/runtime/sys_linux_mipsx.s

@@ -182,12 +182,13 @@ TEXT runtime·walltime(SB),NOSPLIT,$8-12
 	SYSCALL
 	MOVW	4(R29), R3	// sec
 	MOVW	8(R29), R5	// nsec
+	MOVW	$sec+0(FP), R6
 #ifdef GOARCH_mips
-	MOVW	R3, sec_lo+4(FP)
-	MOVW	R0, sec_hi+0(FP)
+	MOVW	R3, 4(R6)
+	MOVW	R0, 0(R6)
 #else
-	MOVW	R3, sec_lo+0(FP)
-	MOVW	R0, sec_hi+4(FP)
+	MOVW	R3, 0(R6)
+	MOVW	R0, 4(R6)
 #endif
 	MOVW	R5, nsec+8(FP)
 	RET
@@ -206,17 +207,18 @@ TEXT runtime·nanotime(SB),NOSPLIT,$8-8
 	MOVW	LO, R3
 	ADDU	R5, R3
 	SGTU	R5, R3, R4
+	MOVW	$ret+0(FP), R6
 #ifdef GOARCH_mips
-	MOVW	R3, ret_lo+4(FP)
+	MOVW	R3, 4(R6)
 #else
-	MOVW	R3, ret_lo+0(FP)
+	MOVW	R3, 0(R6)
 #endif
 	MOVW	HI, R3
 	ADDU	R4, R3
 #ifdef GOARCH_mips
-	MOVW	R3, ret_hi+0(FP)
+	MOVW	R3, 0(R6)
 #else
-	MOVW	R3, ret_hi+4(FP)
+	MOVW	R3, 4(R6)
 #endif
 	RET
 
@@ -369,6 +371,7 @@ TEXT runtime·clone(SB),NOSPLIT|NOFRAME,$0-24
 
 	// In child, on new stack.
 	// Check that SP is as we expect
+	NOP	R29	// tell vet R29/SP changed - stop checking offsets
 	MOVW	12(R29), R16
 	MOVW	$1234, R1
 	BEQ	R16, R1, 2(PC)

src/runtime/sys_linux_ppc64x.s

@@ -285,16 +285,19 @@ TEXT runtime·sigfwd(SB),NOSPLIT,$0-32
 	MOVD	24(R1), R2
 	RET
 
+TEXT runtime·sigreturn(SB),NOSPLIT,$0-0
+	RET
+
 #ifdef GOARCH_ppc64le
 // ppc64le doesn't need function descriptors
 TEXT runtime·sigtramp(SB),NOSPLIT,$64
 #else
 // function descriptor for the real sigtramp
 TEXT runtime·sigtramp(SB),NOSPLIT|NOFRAME,$0
-	DWORD	$runtime·_sigtramp(SB)
+	DWORD	$sigtramp<>(SB)
 	DWORD	$0
 	DWORD	$0
-TEXT runtime·_sigtramp(SB),NOSPLIT,$64
+TEXT sigtramp<>(SB),NOSPLIT,$64
 #endif
 	// initialize essential registers (just in case)
 	BL	runtime·reginit(SB)
@@ -410,11 +413,11 @@ sigtrampnog:
 #else
 // function descriptor for the real sigtramp
 TEXT runtime·cgoSigtramp(SB),NOSPLIT|NOFRAME,$0
-	DWORD	$runtime·_cgoSigtramp(SB)
+	DWORD	$cgoSigtramp<>(SB)
 	DWORD	$0
 	DWORD	$0
-TEXT runtime·_cgoSigtramp(SB),NOSPLIT,$0
-	JMP	runtime·_sigtramp(SB)
+TEXT cgoSigtramp<>(SB),NOSPLIT,$0
+	JMP	sigtramp<>(SB)
 #endif
 
 TEXT runtime·sigprofNonGoWrapper<>(SB),NOSPLIT,$0

src/runtime/sys_linux_s390x.s

@@ -222,6 +222,9 @@ TEXT runtime·sigfwd(SB),NOSPLIT,$0-32
 	BL	R5
 	RET
 
+TEXT runtime·sigreturn(SB),NOSPLIT,$0-0
+	RET
+
 TEXT runtime·sigtramp(SB),NOSPLIT,$64
 	// initialize essential registers (just in case)
 	XOR	R0, R0