cmd/internal/obj: handle static assembly symbols correctly in FIPS check

Static symbols don't have the package prefix, so we need to identify
them specially.

Change-Id: Iaa0456de802478f6a257164e9703f18f8dc7eb50
Reviewed-on: https://go-review.googlesource.com/c/go/+/631975
Reviewed-by: Cherry Mui <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: rsc

src/cmd/internal/obj/fips140.go

@@ -221,47 +221,55 @@ func (s *LSym) setFIPSType(ctxt *Link) {
 		return
 	}
 
-	// Name must begin with crypto/internal/fips140, then dot or slash.
-	// The quick check for 'c' before the string compare is probably overkill,
-	// but this function is called a fair amount, and we don't want to
-	// slow down all the non-FIPS compilations.
-	const prefix = "crypto/internal/fips140"
-	name := s.Name
-	if len(name) <= len(prefix) || (name[len(prefix)] != '.' && name[len(prefix)] != '/') || name[0] != 'c' || name[:len(prefix)] != prefix {
-		return
-	}
-
-	if strings.Contains(name, "_test.") {
-		// External test packages are not in the scope.
+	// External test packages are not in scope.
+	if strings.HasSuffix(ctxt.Pkgpath, "_test") {
 		return
 	}
 
-	// Now we're at least handling a FIPS symbol.
-	// It's okay to be slower now, since this code only runs when compiling a few packages.
-	// Text symbols are always okay, since they can use PC-relative relocations,
-	// but some data symbols are not.
-	if s.Type != objabi.STEXT && s.Type != objabi.STEXTFIPS {
-		// Even in the crypto/internal/fips140 packages,
-		// we exclude various Go runtime metadata,
-		// so that it can be allowed to contain data relocations.
-		if strings.Contains(name, ".inittask") ||
-			strings.Contains(name, ".dict") ||
-			strings.Contains(name, ".typeAssert") ||
-			strings.HasSuffix(name, ".arginfo0") ||
-			strings.HasSuffix(name, ".arginfo1") ||
-			strings.HasSuffix(name, ".argliveinfo") ||
-			strings.HasSuffix(name, ".args_stackmap") ||
-			strings.HasSuffix(name, ".opendefer") ||
-			strings.HasSuffix(name, ".stkobj") ||
-			strings.HasSuffix(name, "·f") {
+	if s.Attribute.Static() {
+		// Static (file-scoped) symbol does not have name prefix,
+		// but must be local to package; rely on whether package is FIPS.
+		if !ctxt.IsFIPS() {
 			return
 		}
-
-		// This symbol is linknamed to go:fipsinfo,
-		// so we shouldn't see it, but skip it just in case.
-		if s.Name == "crypto/internal/fips140/check.linkinfo" {
+	} else {
+		// Name must begin with crypto/internal/fips140, then dot or slash.
+		// The quick check for 'c' before the string compare is probably overkill,
+		// but this function is called a fair amount, and we don't want to
+		// slow down all the non-FIPS compilations.
+		const prefix = "crypto/internal/fips140"
+		name := s.Name
+		if len(name) <= len(prefix) || (name[len(prefix)] != '.' && name[len(prefix)] != '/') || name[0] != 'c' || name[:len(prefix)] != prefix {
 			return
 		}
+
+		// Now we're at least handling a FIPS symbol.
+		// It's okay to be slower now, since this code only runs when compiling a few packages.
+		// Text symbols are always okay, since they can use PC-relative relocations,
+		// but some data symbols are not.
+		if s.Type != objabi.STEXT && s.Type != objabi.STEXTFIPS {
+			// Even in the crypto/internal/fips140 packages,
+			// we exclude various Go runtime metadata,
+			// so that it can be allowed to contain data relocations.
+			if strings.Contains(name, ".inittask") ||
+				strings.Contains(name, ".dict") ||
+				strings.Contains(name, ".typeAssert") ||
+				strings.HasSuffix(name, ".arginfo0") ||
+				strings.HasSuffix(name, ".arginfo1") ||
+				strings.HasSuffix(name, ".argliveinfo") ||
+				strings.HasSuffix(name, ".args_stackmap") ||
+				strings.HasSuffix(name, ".opendefer") ||
+				strings.HasSuffix(name, ".stkobj") ||
+				strings.HasSuffix(name, "·f") {
+				return
+			}
+
+			// This symbol is linknamed to go:fipsinfo,
+			// so we shouldn't see it, but skip it just in case.
+			if s.Name == "crypto/internal/fips140/check.linkinfo" {
+				return
+			}
+		}
 	}
 
 	// This is a FIPS symbol! Convert its type to FIPS.

src/crypto/internal/fips140/check/checktest/asm_386.s

@@ -0,0 +1,23 @@
+// Copyright 2024 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.
+
+//go:build !purego
+
+#include "textflag.h"
+
+DATA StaticData<>(SB)/4, $10
+GLOBL StaticData<>(SB), NOPTR, $4
+
+TEXT StaticText<>(SB), $0
+	RET
+
+TEXT ·PtrStaticData(SB), $0-4
+	MOVL $StaticData<>(SB), AX
+	MOVL AX, ret+0(FP)
+	RET
+
+TEXT ·PtrStaticText(SB), $0-4
+	MOVL $StaticText<>(SB), AX
+	MOVL AX, ret+0(FP)
+	RET

src/crypto/internal/fips140/check/checktest/asm_amd64.s

@@ -0,0 +1,23 @@
+// Copyright 2024 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.
+
+//go:build !purego
+
+#include "textflag.h"
+
+DATA StaticData<>(SB)/4, $10
+GLOBL StaticData<>(SB), NOPTR, $4
+
+TEXT StaticText<>(SB), $0
+	RET
+
+TEXT ·PtrStaticData(SB), $0-8
+	MOVQ $StaticData<>(SB), AX
+	MOVQ AX, ret+0(FP)
+	RET
+
+TEXT ·PtrStaticText(SB), $0-8
+	MOVQ $StaticText<>(SB), AX
+	MOVQ AX, ret+0(FP)
+	RET

src/crypto/internal/fips140/check/checktest/asm_arm.s

@@ -0,0 +1,23 @@
+// Copyright 2024 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.
+
+//go:build !purego
+
+#include "textflag.h"
+
+DATA StaticData<>(SB)/4, $10
+GLOBL StaticData<>(SB), NOPTR, $4
+
+TEXT StaticText<>(SB), $0
+	RET
+
+TEXT ·PtrStaticData(SB), $0-4
+	MOVW $StaticData<>(SB), R1
+	MOVW R1, ret+0(FP)
+	RET
+
+TEXT ·PtrStaticText(SB), $0-4
+	MOVW $StaticText<>(SB), R1
+	MOVW R1, ret+0(FP)
+	RET

src/crypto/internal/fips140/check/checktest/asm_arm64.s

@@ -0,0 +1,23 @@
+// Copyright 2024 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.
+
+//go:build !purego
+
+#include "textflag.h"
+
+DATA StaticData<>(SB)/4, $10
+GLOBL StaticData<>(SB), NOPTR, $4
+
+TEXT StaticText<>(SB), $0
+	RET
+
+TEXT ·PtrStaticData(SB), $0-8
+	MOVD $StaticData<>(SB), R1
+	MOVD R1, ret+0(FP)
+	RET
+
+TEXT ·PtrStaticText(SB), $0-8
+	MOVD $StaticText<>(SB), R1
+	MOVD R1, ret+0(FP)
+	RET

src/crypto/internal/fips140/check/checktest/asm_none.go

@@ -0,0 +1,12 @@
+// Copyright 2024 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.
+
+//go:build (!386 && !amd64 && !arm && !arm64) || purego
+
+package checktest
+
+import "unsafe"
+
+func PtrStaticData() *uint32        { return nil }
+func PtrStaticText() unsafe.Pointer { return nil }

src/crypto/internal/fips140/check/checktest/asm_stub.go

@@ -0,0 +1,12 @@
+// Copyright 2024 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.
+
+//go:build (386 || amd64 || arm || arm64) && !purego
+
+package checktest
+
+import "unsafe"
+
+func PtrStaticData() *uint32
+func PtrStaticText() unsafe.Pointer

src/crypto/internal/fips140test/check_test.go

@@ -80,6 +80,9 @@ func TestFIPSCheckInfo(t *testing.T) {
 	if checktest.BSS != nil {
 		t.Errorf("checktest.BSS = %p, want nil", checktest.BSS)
 	}
+	if p := checktest.PtrStaticData(); p != nil && *p != 10 {
+		t.Errorf("*checktest.PtrStaticData() = %d, want 10", *p)
+	}
 
 	// Check that the checktest symbols are in the right go:fipsinfo sections.
 	sect := func(i int, name string, p unsafe.Pointer) {
@@ -89,8 +92,14 @@ func TestFIPSCheckInfo(t *testing.T) {
 		}
 	}
 	sect(0, "TEXT", unsafe.Pointer(abi.FuncPCABIInternal(checktest.TEXT)))
+	if p := checktest.PtrStaticText(); p != nil {
+		sect(0, "StaticText", p)
+	}
 	sect(1, "RODATA", unsafe.Pointer(&checktest.RODATA))
 	sect(2, "NOPTRDATA", unsafe.Pointer(&checktest.NOPTRDATA))
+	if p := checktest.PtrStaticData(); p != nil {
+		sect(2, "StaticData", unsafe.Pointer(p))
+	}
 	sect(3, "DATA", unsafe.Pointer(&checktest.DATA))
 
 	// Check that some symbols are not in FIPS sections.