From 50f65726a9ac8d6dd4bd2c1c609db16debd98d5c Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Wed, 14 Feb 2018 07:42:40 -0800 Subject: [release-branch.go1.9] cmd/compile: permit go:cgo_import_dynamic anywhere It's used on Solaris to import symbols from shared libraries, e.g., in golang.org/x/sys/unix and golang.org/x/net/internal/socket. We could use a different directive but that would require build tags in all the places that use it. Fixes golang/go#23939 Change-Id: I47fcf72a6d2862e304204705979c2056c2f78ec5 Reviewed-on: https://go-review.googlesource.com/94018 Run-TryBot: Andrew Bonventre TryBot-Result: Gobot Gobot Reviewed-by: Brad Fitzpatrick (cherry picked from commit 41d3d153eb76f000e9f6e9edf68ed441d15081cb) Reviewed-on: https://go-review.googlesource.com/110077 Reviewed-by: Ian Lance Taylor --- src/cmd/compile/internal/gc/noder.go | 28 +++++++++++++++++++++++++++- src/cmd/go/internal/load/pkg.go | 1 + 2 files changed, 28 insertions(+), 1 deletion(-) diff --git a/src/cmd/compile/internal/gc/noder.go b/src/cmd/compile/internal/gc/noder.go index 7cd941206b..37fad2d714 100644 --- a/src/cmd/compile/internal/gc/noder.go +++ b/src/cmd/compile/internal/gc/noder.go @@ -1190,8 +1190,22 @@ func (p *noder) pragma(pos src.Pos, text string) syntax.Pragma { } p.linknames = append(p.linknames, linkname{pos, f[1], f[2]}) + case strings.HasPrefix(text, "go:cgo_import_dynamic "): + // This is permitted for general use because Solaris + // code relies on it in golang.org/x/sys/unix and others. + fields := pragmaFields(text) + if len(fields) >= 4 { + lib := strings.Trim(fields[3], `"`) + if lib != "" && !safeArg(lib) && !isCgoGeneratedFile(pos) { + p.error(syntax.Error{Pos: pos, Msg: fmt.Sprintf("invalid library name %q in cgo_import_dynamic directive", lib)}) + } + p.pragcgobuf += p.pragcgo(pos, text) + return pragmaValue("go:cgo_import_dynamic") + } + fallthrough case strings.HasPrefix(text, "go:cgo_"): - // For security, we disallow //go:cgo_* directives outside cgo-generated files. + // For security, we disallow //go:cgo_* directives other + // than cgo_import_dynamic outside cgo-generated files. // Exception: they are allowed in the standard library, for runtime and syscall. if !isCgoGeneratedFile(pos) && !compiling_std { p.error(syntax.Error{Pos: pos, Msg: fmt.Sprintf("//%s only allowed in cgo-generated code", text)}) @@ -1227,6 +1241,18 @@ func isCgoGeneratedFile(pos src.Pos) bool { return strings.HasPrefix(filepath.Base(filepath.Clean(pos.AbsFilename())), "_cgo_") } +// safeArg reports whether arg is a "safe" command-line argument, +// meaning that when it appears in a command-line, it probably +// doesn't have some special meaning other than its own name. +// This is copied from SafeArg in cmd/go/internal/load/pkg.go. +func safeArg(name string) bool { + if name == "" { + return false + } + c := name[0] + return '0' <= c && c <= '9' || 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || c == '.' || c == '_' || c == '/' || c >= utf8.RuneSelf +} + func mkname(sym *types.Sym) *Node { n := oldname(sym) if n.Name != nil && n.Name.Pack != nil { diff --git a/src/cmd/go/internal/load/pkg.go b/src/cmd/go/internal/load/pkg.go index 65b17012a3..6ca89d946d 100644 --- a/src/cmd/go/internal/load/pkg.go +++ b/src/cmd/go/internal/load/pkg.go @@ -1218,6 +1218,7 @@ func (p *Package) load(stk *ImportStack, bp *build.Package, err error) *Package // GNU binutils flagfile specifiers, sometimes called "response files"). // To be conservative, we reject almost any arg beginning with non-alphanumeric ASCII. // We accept leading . _ and / as likely in file system paths. +// There is a copy of this function in cmd/compile/internal/gc/noder.go. func SafeArg(name string) bool { if name == "" { return false -- cgit v1.2.3-54-g00ecf