runtime: fix vet complaints for linux/386

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

This CL makes "GOOS=linux GOARCH=386 go vet -unsafeptr=false runtime" happy,
while keeping "GO_BUILDER_NAME=misc-vetall go tool dist test" happy too.

For #31916.

Change-Id: I3e5586a7ff6e359357350d0602c2259493280ded
Reviewed-on: https://go-review.googlesource.com/c/go/+/176099
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

src/cmd/vet/all/whitelist/386.txt

-// 386-specific vet whitelist. See readme.txt for details.
-
-// startup code uses non-standard calling convention and intentionally
-// omits args.
-runtime/asm_386.s: [386] rt0_go: use of 4(SP) points beyond argument frame
-
-// reflect trampolines intentionally omit arg size. Same for morestack.
-runtime/asm_386.s: [386] morestack: use of 4(SP) points beyond argument frame
-runtime/asm_386.s: [386] morestack: use of 8(SP) points beyond argument frame
-runtime/asm_386.s: [386] morestack: use of 4(SP) points beyond argument frame
-
-// Intentionally missing declarations. These are special assembly routines.
-runtime/asm_386.s: [386] ldt0setup: function ldt0setup missing Go declaration
-runtime/asm_386.s: [386] emptyfunc: function emptyfunc missing Go declaration
-runtime/asm_386.s: [386] aeshashbody: function aeshashbody missing Go declaration
-runtime/asm_386.s: [386] addmoduledata: function addmoduledata missing Go declaration
-runtime/duff_386.s: [386] duffzero: function duffzero missing Go declaration
-runtime/duff_386.s: [386] duffcopy: function duffcopy missing Go declaration

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

@@ -13,6 +13,3 @@ runtime/asm_amd64.s: [amd64] morestack: use of 8(SP) points beyond argument fram
 // Others use the platform ABI.
 // There is no sensible corresponding Go prototype.
 runtime/asm_amd64.s: [amd64] aeshashbody: function aeshashbody missing Go declaration
-runtime/asm_amd64.s: [amd64] addmoduledata: function addmoduledata missing Go declaration
-runtime/duff_amd64.s: [amd64] duffzero: function duffzero missing Go declaration
-runtime/duff_amd64.s: [amd64] duffcopy: function duffcopy missing Go declaration

src/cmd/vet/all/whitelist/android_386.txt

-// android/386-specific vet whitelist. See readme.txt for details.
-
-runtime/sys_linux_386.s: [386] setldt: function setldt missing Go declaration
-
-// These SP references occur after a stack-altering call. They're fine.
-runtime/sys_linux_386.s: [386] clone: 12(SP) should be mp+8(FP)
-runtime/sys_linux_386.s: [386] clone: 4(SP) should be flags+0(FP)
-runtime/sys_linux_386.s: [386] clone: 8(SP) should be stk+4(FP)

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

@@ -3,8 +3,5 @@
 // Intentionally missing declarations.
 runtime/asm_arm.s: [arm] emptyfunc: function emptyfunc missing Go declaration
 runtime/asm_arm.s: [arm] usplitR0: function usplitR0 missing Go declaration
-runtime/asm_arm.s: [arm] addmoduledata: function addmoduledata missing Go declaration
-runtime/duff_arm.s: [arm] duffzero: function duffzero missing Go declaration
-runtime/duff_arm.s: [arm] duffcopy: function duffcopy missing Go declaration
 runtime/tls_arm.s: [arm] load_g: function load_g missing Go declaration
 runtime/tls_arm.s: [arm] _initcgo: function _initcgo missing Go declaration

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

 // arm64-specific vet whitelist. See readme.txt for details.
 
 // Intentionally missing declarations.
-runtime/asm_arm64.s: [arm64] addmoduledata: function addmoduledata missing Go declaration
 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/darwin_386.txt

-// darwin/386-specific vet whitelist. See readme.txt for details.
-
-// Ok
-
-runtime/sys_darwin_386.s: [386] setldt: function setldt missing Go declaration

src/cmd/vet/all/whitelist/freebsd_386.txt

@@ -5,7 +5,6 @@ runtime/sys_freebsd_386.s: [386] sigtramp: unknown variable signo
 runtime/sys_freebsd_386.s: [386] sigtramp: unknown variable info
 runtime/sys_freebsd_386.s: [386] sigtramp: unknown variable context
 runtime/sys_freebsd_386.s: [386] sigtramp: unknown variable context
-runtime/sys_freebsd_386.s: [386] setldt: function setldt missing Go declaration
 runtime/sys_freebsd_386.s: [386] i386_set_ldt: function i386_set_ldt 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)

src/cmd/vet/all/whitelist/linux_386.txt

-// linux/386-specific vet whitelist. See readme.txt for details.
-
-runtime/sys_linux_386.s: [386] setldt: function setldt missing Go declaration
-
-// These SP references occur after a stack-altering call. They're fine.
-runtime/sys_linux_386.s: [386] clone: 12(SP) should be mp+8(FP)
-runtime/sys_linux_386.s: [386] clone: 4(SP) should be flags+0(FP)
-runtime/sys_linux_386.s: [386] clone: 8(SP) should be stk+4(FP)
-
-// Android-specific; stubs missing on other linux platforms.
-runtime/sys_linux_386.s: [386] access: function access missing Go declaration
-runtime/sys_linux_386.s: [386] connect: function connect missing Go declaration
-runtime/sys_linux_386.s: [386] socket: function socket 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
-
-// Android-specific; stubs missing on other linux platforms.
-runtime/sys_linux_amd64.s: [amd64] access: function access missing Go declaration
-runtime/sys_linux_amd64.s: [amd64] connect: function connect missing Go declaration
-runtime/sys_linux_amd64.s: [amd64] socket: function socket missing Go declaration

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

 // linux/arm-specific vet whitelist. See readme.txt for details.
 
-
 // These SP references occur after a stack-altering call. They're fine.
 runtime/sys_linux_arm.s: [arm] clone: 12(R13) should be stk+4(FP)
 runtime/sys_linux_arm.s: [arm] clone: 8(R13) should be flags+0(FP)
-
-// Special functions.
-runtime/sys_linux_arm.s: [arm] access: function access missing Go declaration
-runtime/sys_linux_arm.s: [arm] connect: function connect missing Go declaration
-runtime/sys_linux_arm.s: [arm] socket: function socket missing Go declaration

src/cmd/vet/all/whitelist/linux_arm64.txt

-// linux/arm64-specific vet whitelist. See readme.txt for details.
-
-runtime/sys_linux_arm64.s: [arm64] access: function access missing Go declaration
-runtime/sys_linux_arm64.s: [arm64] connect: function connect missing Go declaration
-runtime/sys_linux_arm64.s: [arm64] socket: function socket missing Go declaration

src/cmd/vet/all/whitelist/nacl_386.txt

 // nacl/386-specific vet whitelist. See readme.txt for details.
 
 runtime/sys_nacl_386.s: [386] nacl_clock_gettime: function nacl_clock_gettime missing Go declaration
-runtime/sys_nacl_386.s: [386] setldt: function setldt missing Go declaration
 runtime/sys_nacl_386.s: [386] sigtramp: use of 20(SP) points beyond argument frame
 runtime/sys_nacl_386.s: [386] sigtramp: use of 4(SP) points beyond argument frame
 runtime/sys_nacl_386.s: [386] sigtramp: unknown variable ctxt

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

@@ -9,8 +9,6 @@ runtime/sys_netbsd_386.s: [386] sigreturn_tramp: use of 4(SP) points beyond argu
 runtime/sys_netbsd_386.s: [386] sigtramp: unknown variable signo
 runtime/sys_netbsd_386.s: [386] sigtramp: unknown variable info
 runtime/sys_netbsd_386.s: [386] sigtramp: unknown variable context
-runtime/sys_netbsd_386.s: [386] setldt: function setldt missing Go declaration
-runtime/sys_netbsd_386.s: [386] setldt: use of 16(SP) points beyond argument frame
 
 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)

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] setldt: function setldt missing Go declaration
 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)

src/cmd/vet/all/whitelist/plan9_386.txt

-// plan9/386-specific vet whitelist. See readme.txt for details.
-
-runtime/sys_plan9_386.s: [386] setldt: function setldt 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] setldt: function setldt missing Go declaration
 runtime/sys_plan9_amd64.s: [amd64] settls: function settls missing Go declaration

src/cmd/vet/all/whitelist/windows_386.txt

@@ -2,7 +2,6 @@
 
 runtime/sys_windows_386.s: [386] profileloop: use of 4(SP) points beyond argument frame
 runtime/sys_windows_386.s: [386] ctrlhandler: 4(SP) should be _type+0(FP)
-runtime/sys_windows_386.s: [386] setldt: function setldt missing Go declaration
 runtime/sys_windows_386.s: [386] callbackasm1+0: function callbackasm1+0 missing Go declaration
 runtime/sys_windows_386.s: [386] tstart: function tstart missing Go declaration
 runtime/sys_windows_386.s: [386] tstart_stdcall: RET without writing to 4-byte ret+4(FP)

src/runtime/asm_386.s

@@ -89,7 +89,7 @@ GLOBL _rt0_386_lib_argc<>(SB),NOPTR, $4
 DATA _rt0_386_lib_argv<>(SB)/4, $0
 GLOBL _rt0_386_lib_argv<>(SB),NOPTR, $4
 
-TEXT runtime·rt0_go(SB),NOSPLIT,$0
+TEXT runtime·rt0_go(SB),NOSPLIT|NOFRAME,$0
 	// Copy arguments forward on an even stack.
 	// Users of this function jump to it, they don't call it.
 	MOVL	0(SP), AX
@@ -209,7 +209,7 @@ needtls:
 #endif
 
 	// set up %gs
-	CALL	runtime·ldt0setup(SB)
+	CALL	ldt0setup<>(SB)
 
 	// store through it, to make sure it works
 	get_tls(BX)
@@ -453,6 +453,7 @@ 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
 	MOVL	4(SP), DI	// f's caller's PC
 	MOVL	DI, (m_morebuf+gobuf_pc)(BX)
 	LEAL	8(SP), CX	// f's caller's SP
@@ -895,7 +896,7 @@ done:
 	MOVL	DX, ret_hi+4(FP)
 	RET
 
-TEXT runtime·ldt0setup(SB),NOSPLIT,$16-0
+TEXT ldt0setup<>(SB),NOSPLIT,$16-0
 	// set up ldt 7 to point at m0.tls
 	// ldt 1 would be fine on Linux, but on OS X, 7 is as low as we can go.
 	// the entry number is just a hint.  setldt will set up GS with what it used.
@@ -914,19 +915,19 @@ TEXT runtime·aeshash(SB),NOSPLIT,$0-16
 	MOVL	p+0(FP), AX	// ptr to data
 	MOVL	s+8(FP), BX	// size
 	LEAL	ret+12(FP), DX
-	JMP	runtime·aeshashbody(SB)
+	JMP	aeshashbody<>(SB)
 
 TEXT runtime·aeshashstr(SB),NOSPLIT,$0-12
 	MOVL	p+0(FP), AX	// ptr to string object
 	MOVL	4(AX), BX	// length of string
 	MOVL	(AX), AX	// string data
 	LEAL	ret+8(FP), DX
-	JMP	runtime·aeshashbody(SB)
+	JMP	aeshashbody<>(SB)
 
 // AX: data
 // BX: length
 // DX: address to put return value
-TEXT runtime·aeshashbody(SB),NOSPLIT,$0-0
+TEXT aeshashbody<>(SB),NOSPLIT,$0-0
 	MOVL	h+4(FP), X0	            // 32 bits of per-table hash seed
 	PINSRW	$4, BX, X0	            // 16 bits of length
 	PSHUFHW	$0, X0, X0	            // replace size with its low 2 bytes repeated 4 times

src/runtime/asm_arm.s

@@ -893,7 +893,7 @@ TEXT runtime·usplitR0(SB),NOSPLIT,$0
 
 #ifndef GOOS_nacl
 // This is called from .init_array and follows the platform, not Go, ABI.
-TEXT runtime·addmoduledata(SB),NOSPLIT,$0-8
+TEXT runtime·addmoduledata(SB),NOSPLIT,$0-0
 	MOVW	R9, saver9-4(SP) // The access to global variables below implicitly uses R9, which is callee-save
 	MOVW	R11, saver11-8(SP) // Likewise, R11 is the temp register, but callee-save in C ABI
 	MOVW	runtime·lastmoduledatap(SB), R1

src/runtime/duff_mips64x.s

@@ -266,3 +266,6 @@ TEXT runtime·duffzero(SB), NOSPLIT|NOFRAME, $0-0
 	RET
 
 // TODO: Implement runtime·duffcopy.
+TEXT runtime·duffcopy(SB),NOSPLIT|NOFRAME,$0-0
+	MOVV	R0, 2(R0)
+	RET

src/runtime/duff_ppc64x.s

@@ -138,3 +138,6 @@ TEXT runtime·duffzero(SB), NOSPLIT|NOFRAME, $0-0
 	RET
 
 // TODO: Implement runtime·duffcopy.
+TEXT runtime·duffcopy(SB),NOSPLIT|NOFRAME,$0-0
+	MOVD	R0, 0(R0)
+	RET

src/runtime/stubs.go

@@ -319,3 +319,8 @@ func abort()
 
 // Called from compiled code; declared for vet; do NOT call from Go.
 func gcWriteBarrier()
+func duffzero()
+func duffcopy()
+
+// Called from linker-generated .initarray; declared for go vet; do NOT call from Go.
+func addmoduledata()

src/runtime/stubs_386.go

@@ -4,5 +4,11 @@
 
 package runtime
 
+import "unsafe"
+
 func float64touint32(a float64) uint32
 func uint32tofloat64(a uint32) float64
+
+// Called from assembly only; declared for go vet.
+func setldt(slot uintptr, base unsafe.Pointer, size uintptr)
+func emptyfunc()

src/runtime/stubs_android.go

-package runtime
-
-import "unsafe"
-
-// Return values of access/connect/socket are the return values of the syscall
-// (may encode error numbers).
-
-// int access(const char *, int)
-//go:noescape
-func access(name *byte, mode int32) int32
-
-// int connect(int, const struct sockaddr*, socklen_t)
-func connect(fd int32, addr unsafe.Pointer, len int32) int32
-
-// int socket(int, int, int)
-func socket(domain int32, typ int32, prot int32) int32

src/runtime/stubs_linux.go

@@ -6,4 +6,14 @@
 
 package runtime
 
+import "unsafe"
+
 func sbrk0() uintptr
+
+// Called from write_err_android.go only, but defined in sys_linux_*.s;
+// declared here (instead of in write_err_android.go) for go vet on non-android builds.
+// The return value is the raw syscall result, which may encode an error number.
+//go:noescape
+func access(name *byte, mode int32) int32
+func connect(fd int32, addr unsafe.Pointer, len int32) int32
+func socket(domain int32, typ int32, prot int32) int32

src/runtime/sys_freebsd_386.s

@@ -295,7 +295,7 @@ int i386_set_ldt(int, const union ldt_entry *, int);
 
 // setldt(int entry, int address, int limit)
 TEXT runtime·setldt(SB),NOSPLIT,$32
-	MOVL	address+4(FP), BX	// aka base
+	MOVL	base+4(FP), BX
 	// see comment in sys_linux_386.s; freebsd is similar
 	ADDL	$0x4, BX
 

src/runtime/sys_linux_386.s

@@ -474,6 +474,7 @@ TEXT runtime·clone(SB),NOSPLIT,$0
 	RET
 
 	// Paranoia: check that SP is as we expect.
+	NOP	SP // tell vet SP changed - stop checking offsets
 	MOVL	12(SP), BP
 	CMPL	BP, $1234
 	JEQ	2(PC)
@@ -572,7 +573,7 @@ GLOBL runtime·tls_entry_number(SB), NOPTR, $4
 // The name, setldt, is a misnomer, although we leave this name as it is for
 // the compatibility with other platforms.
 TEXT runtime·setldt(SB),NOSPLIT,$32
-	MOVL	address+4(FP), DX	// base address
+	MOVL	base+4(FP), DX
 
 #ifdef GOOS_android
 	// Android stores the TLS offset in runtime·tls_g.

src/runtime/sys_linux_mips64x.s

@@ -462,3 +462,18 @@ TEXT runtime·sbrk0(SB),NOSPLIT|NOFRAME,$0-8
 	SYSCALL
 	MOVV	R2, ret+0(FP)
 	RET
+
+TEXT runtime·access(SB),$0-20
+	MOVV	R0, 2(R0) // unimplemented, only needed for android; declared in stubs_linux.go
+	MOVW	R0, ret+16(FP) // for vet
+	RET
+
+TEXT runtime·connect(SB),$0-28
+	MOVV	R0, 2(R0) // unimplemented, only needed for android; declared in stubs_linux.go
+	MOVW	R0, ret+24(FP) // for vet
+	RET
+
+TEXT runtime·socket(SB),$0-20
+	MOVV	R0, 2(R0) // unimplemented, only needed for android; declared in stubs_linux.go
+	MOVW	R0, ret+16(FP) // for vet
+	RET

src/runtime/sys_linux_mipsx.s

@@ -492,3 +492,18 @@ TEXT runtime·sbrk0(SB),NOSPLIT,$0-4
 	SYSCALL
 	MOVW	R2, ret+0(FP)
 	RET
+
+TEXT runtime·access(SB),$0-12
+	BREAK // unimplemented, only needed for android; declared in stubs_linux.go
+	MOVW	R0, ret+8(FP)	// for vet
+	RET
+
+TEXT runtime·connect(SB),$0-16
+	BREAK // unimplemented, only needed for android; declared in stubs_linux.go
+	MOVW	R0, ret+12(FP)	// for vet
+	RET
+
+TEXT runtime·socket(SB),$0-16
+	BREAK // unimplemented, only needed for android; declared in stubs_linux.go
+	MOVW	R0, ret+12(FP)	// for vet
+	RET

src/runtime/sys_linux_ppc64x.s

@@ -616,3 +616,18 @@ TEXT runtime·sbrk0(SB),NOSPLIT|NOFRAME,$0
 	SYSCALL	$SYS_brk
 	MOVD	R3, ret+0(FP)
 	RET
+
+TEXT runtime·access(SB),$0-20
+	MOVD	R0, 0(R0) // unimplemented, only needed for android; declared in stubs_linux.go
+	MOVW	R0, ret+16(FP) // for vet
+	RET
+
+TEXT runtime·connect(SB),$0-28
+	MOVD	R0, 0(R0) // unimplemented, only needed for android; declared in stubs_linux.go
+	MOVW	R0, ret+24(FP) // for vet
+	RET
+
+TEXT runtime·socket(SB),$0-20
+	MOVD	R0, 0(R0) // unimplemented, only needed for android; declared in stubs_linux.go
+	MOVW	R0, ret+16(FP) // for vet
+	RET

src/runtime/sys_linux_s390x.s

@@ -446,3 +446,18 @@ TEXT runtime·sbrk0(SB),NOSPLIT|NOFRAME,$0-8
 	SYSCALL
 	MOVD	R2, ret+0(FP)
 	RET
+
+TEXT runtime·access(SB),$0-20
+	MOVD	$0, 2(R0) // unimplemented, only needed for android; declared in stubs_linux.go
+	MOVW	R0, ret+16(FP)
+	RET
+
+TEXT runtime·connect(SB),$0-28
+	MOVD	$0, 2(R0) // unimplemented, only needed for android; declared in stubs_linux.go
+	MOVW	R0, ret+24(FP)
+	RET
+
+TEXT runtime·socket(SB),$0-20
+	MOVD	$0, 2(R0) // unimplemented, only needed for android; declared in stubs_linux.go
+	MOVW	R0, ret+16(FP)
+	RET

src/runtime/sys_nacl_386.s

@@ -287,7 +287,7 @@ TEXT runtime·nanotime(SB),NOSPLIT,$20
 	RET
 
 TEXT runtime·setldt(SB),NOSPLIT,$8
-	MOVL	addr+4(FP), BX // aka base
+	MOVL	base+4(FP), BX
 	ADDL	$0x8, BX
 	MOVL	BX, 0(SP)
 	NACL_SYSCALL(SYS_tls_init)

src/runtime/sys_netbsd_386.s

@@ -361,7 +361,7 @@ TEXT runtime·sigaltstack(SB),NOSPLIT,$-8
 
 TEXT runtime·setldt(SB),NOSPLIT,$8
 	// Under NetBSD we set the GS base instead of messing with the LDT.
-	MOVL	16(SP), AX		// tls0
+	MOVL	base+4(FP), AX
 	MOVL	AX, 0(SP)
 	CALL	runtime·settls(SB)
 	RET

src/runtime/sys_openbsd_386.s

@@ -329,7 +329,7 @@ TEXT runtime·sigaltstack(SB),NOSPLIT,$-8
 
 TEXT runtime·setldt(SB),NOSPLIT,$4
 	// Under OpenBSD we set the GS base instead of messing with the LDT.
-	MOVL	tls0+4(FP), AX
+	MOVL	base+4(FP), AX
 	MOVL	AX, 0(SP)
 	CALL	runtime·settls(SB)
 	RET

src/runtime/sys_plan9_amd64.s

@@ -6,10 +6,6 @@
 #include "go_tls.h"
 #include "textflag.h"
 
-// setldt(int entry, int address, int limit)
-TEXT runtime·setldt(SB),NOSPLIT,$0
-	RET
-
 TEXT runtime·open(SB),NOSPLIT,$0
 	MOVQ	$14, BP
 	SYSCALL

src/runtime/sys_windows_386.s

@@ -354,7 +354,7 @@ TEXT runtime·tstart_stdcall(SB),NOSPLIT,$0
 
 // setldt(int entry, int address, int limit)
 TEXT runtime·setldt(SB),NOSPLIT,$0
-	MOVL	address+4(FP), CX
+	MOVL	base+4(FP), CX
 	MOVL	CX, 0x14(FS)
 	RET