cmd/go: add options to security whitelist

Also permit passing flags to pkg-config, as we used to.

Also change the error message to refer to https://golang.org/s/invalidflag.

Fixes #23749

Change-Id: I3fbeb4c346610e6fd55e8720e720b0a40e352ab5
Reviewed-on: https://go-review.googlesource.com/93836
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/cmd/go/internal/work/exec.go

@@ -935,15 +935,20 @@ func splitPkgConfigOutput(out []byte) []string {
 // Calls pkg-config if needed and returns the cflags/ldflags needed to build the package.
 func (b *Builder) getPkgConfigFlags(p *load.Package) (cflags, ldflags []string, err error) {
 	if pkgs := p.CgoPkgConfig; len(pkgs) > 0 {
+		var pcflags []string
+		for len(pkgs) > 0 && strings.HasPrefix(pkgs[0], "--") {
+			pcflags = append(pcflags, pkgs[0])
+			pkgs = pkgs[1:]
+		}
 		for _, pkg := range pkgs {
 			if !load.SafeArg(pkg) {
 				return nil, nil, fmt.Errorf("invalid pkg-config package name: %s", pkg)
 			}
 		}
 		var out []byte
-		out, err = b.runOut(p.Dir, p.ImportPath, nil, b.PkgconfigCmd(), "--cflags", "--", pkgs)
+		out, err = b.runOut(p.Dir, p.ImportPath, nil, b.PkgconfigCmd(), "--cflags", pcflags, "--", pkgs)
 		if err != nil {
-			b.showOutput(nil, p.Dir, b.PkgconfigCmd()+" --cflags "+strings.Join(pkgs, " "), string(out))
+			b.showOutput(nil, p.Dir, b.PkgconfigCmd()+" --cflags "+strings.Join(pcflags, " ")+strings.Join(pkgs, " "), string(out))
 			b.Print(err.Error() + "\n")
 			return nil, nil, errPrintedOutput
 		}
@@ -953,15 +958,15 @@ func (b *Builder) getPkgConfigFlags(p *load.Package) (cflags, ldflags []string,
 				return nil, nil, err
 			}
 		}
-		out, err = b.runOut(p.Dir, p.ImportPath, nil, b.PkgconfigCmd(), "--libs", "--", pkgs)
+		out, err = b.runOut(p.Dir, p.ImportPath, nil, b.PkgconfigCmd(), "--libs", pcflags, "--", pkgs)
 		if err != nil {
-			b.showOutput(nil, p.Dir, b.PkgconfigCmd()+" --libs "+strings.Join(pkgs, " "), string(out))
+			b.showOutput(nil, p.Dir, b.PkgconfigCmd()+" --libs "+strings.Join(pcflags, " ")+strings.Join(pkgs, " "), string(out))
 			b.Print(err.Error() + "\n")
 			return nil, nil, errPrintedOutput
 		}
 		if len(out) > 0 {
 			ldflags = strings.Fields(string(out))
-			if err := checkLinkerFlags("CFLAGS", "pkg-config --cflags", ldflags); err != nil {
+			if err := checkLinkerFlags("LDFLAGS", "pkg-config --libs", ldflags); err != nil {
 				return nil, nil, err
 			}
 		}

src/cmd/go/internal/work/security.go

@@ -34,6 +34,7 @@ import (
 	"fmt"
 	"os"
 	"regexp"
+	"strings"
 )
 
 var re = regexp.MustCompile
@@ -45,26 +46,42 @@ var validCompilerFlags = []*regexp.Regexp{
 	re(`-O([^@\-].*)`),
 	re(`-W`),
 	re(`-W([^@,]+)`), // -Wall but not -Wa,-foo.
+	re(`-f(no-)?blocks`),
+	re(`-f(no-)?common`),
+	re(`-f(no-)?constant-cfstrings`),
+	re(`-f(no-)?exceptions`),
+	re(`-finput-charset=([^@\-].*)`),
+	re(`-f(no-)?lto`),
+	re(`-f(no-)?modules`),
 	re(`-f(no-)?objc-arc`),
 	re(`-f(no-)?omit-frame-pointer`),
+	re(`-f(no-)?openmp(-simd)?`),
+	re(`-f(no-)?permissive`),
 	re(`-f(no-)?(pic|PIC|pie|PIE)`),
+	re(`-f(no-)?rtti`),
 	re(`-f(no-)?split-stack`),
 	re(`-f(no-)?stack-(.+)`),
 	re(`-f(no-)?strict-aliasing`),
 	re(`-fsanitize=(.+)`),
 	re(`-g([^@\-].*)?`),
 	re(`-m(arch|cpu|fpu|tune)=([^@\-].*)`),
+	re(`-m(no-)?avx[0-9a-z.]*`),
+	re(`-m(no-)?ms-bitfields`),
 	re(`-m(no-)?stack-(.+)`),
 	re(`-mmacosx-(.+)`),
 	re(`-mnop-fun-dllimport`),
+	re(`-m(no-)?sse[0-9.]*`),
+	re(`-pedantic(-errors)?`),
+	re(`-pipe`),
 	re(`-pthread`),
-	re(`-std=([^@\-].*)`),
+	re(`-?-std=([^@\-].*)`),
 	re(`-x([^@\-].*)`),
 }
 
 var validCompilerFlagsWithNextArg = []string{
 	"-D",
 	"-I",
+	"-isystem",
 	"-framework",
 	"-x",
 }
@@ -79,16 +96,29 @@ var validLinkerFlags = []*regexp.Regexp{
 	re(`-m(arch|cpu|fpu|tune)=([^@\-].*)`),
 	re(`-(pic|PIC|pie|PIE)`),
 	re(`-pthread`),
+	re(`-?-static([-a-z0-9+]*)`),
 
 	// Note that any wildcards in -Wl need to exclude comma,
 	// since -Wl splits its argument at commas and passes
 	// them all to the linker uninterpreted. Allowing comma
 	// in a wildcard would allow tunnelling arbitrary additional
 	// linker arguments through one of these.
+	re(`-Wl,--(no-)?as-needed`),
+	re(`-Wl,-Bdynamic`),
+	re(`-Wl,-Bstatic`),
+	re(`-Wl,--disable-new-dtags`),
+	re(`-Wl,--enable-new-dtags`),
+	re(`-Wl,--end-group`),
+	re(`-Wl,-framework,[^,@\-][^,]+`),
+	re(`-Wl,-headerpad_max_install_names`),
+	re(`-Wl,--no-undefined`),
 	re(`-Wl,-rpath,([^,@\-][^,]+)`),
+	re(`-Wl,-search_paths_first`),
+	re(`-Wl,--start-group`),
+	re(`-Wl,-?-unresolved-symbols=[^,]+`),
 	re(`-Wl,--(no-)?warn-([^,]+)`),
 
-	re(`[a-zA-Z0-9_].*\.(o|obj|dll|dylib|so)`), // direct linker inputs: x.o or libfoo.so (but not -foo.o or @foo.o)
+	re(`[a-zA-Z0-9_/].*\.(a|o|obj|dll|dylib|so)`), // direct linker inputs: x.o or libfoo.so (but not -foo.o or @foo.o)
 }
 
 var validLinkerFlagsWithNextArg = []string{
@@ -96,6 +126,7 @@ var validLinkerFlagsWithNextArg = []string{
 	"-l",
 	"-L",
 	"-framework",
+	"-Wl,-framework",
 }
 
 func checkCompilerFlags(name, source string, list []string) error {
@@ -147,10 +178,21 @@ Args:
 					i++
 					continue Args
 				}
+
+				// Permit -Wl,-framework -Wl,name.
+				if i+1 < len(list) &&
+					strings.HasPrefix(arg, "-Wl,") &&
+					strings.HasPrefix(list[i+1], "-Wl,") &&
+					load.SafeArg(list[i+1][4:]) &&
+					!strings.Contains(list[i+1][4:], ",") {
+					i++
+					continue Args
+				}
+
 				if i+1 < len(list) {
-					return fmt.Errorf("invalid flag in %s: %s %s", source, arg, list[i+1])
+					return fmt.Errorf("invalid flag in %s: %s %s (see https://golang.org/s/invalidflag)", source, arg, list[i+1])
 				}
-				return fmt.Errorf("invalid flag in %s: %s without argument", source, arg)
+				return fmt.Errorf("invalid flag in %s: %s without argument (see https://golang.org/s/invalidflag)", source, arg)
 			}
 		}
 	Bad:

src/cmd/go/internal/work/security_test.go

@@ -132,6 +132,9 @@ var goodLinkerFlags = [][]string{
 	{"-l", "世界"},
 	{"-L", "framework"},
 	{"-framework", "Chocolate"},
+	{"-Wl,-framework", "-Wl,Chocolate"},
+	{"-Wl,-framework,Chocolate"},
+	{"-Wl,-unresolved-symbols=ignore-all"},
 }
 
 var badLinkerFlags = [][]string{
@@ -185,6 +188,10 @@ var badLinkerFlags = [][]string{
 	{"-l", "-foo"},
 	{"-framework", "-Caffeine"},
 	{"-framework", "@Home"},
+	{"-Wl,-framework,-Caffeine"},
+	{"-Wl,-framework", "-Wl,@Home"},
+	{"-Wl,-framework", "@Home"},
+	{"-Wl,-framework,Chocolate,@Home"},
 	{"-x", "--c"},
 	{"-x", "@obj"},
 	{"-Wl,-rpath,@foo"},