diff --git a/misc/cgo/testshared/shared_test.go b/misc/cgo/testshared/shared_test.go
index 1d731af2a2..f7a99afce4 100644
--- a/misc/cgo/testshared/shared_test.go
+++ b/misc/cgo/testshared/shared_test.go
@@ -368,6 +368,21 @@ func testABIHashNote(t *testing.T, f *elf.File, note *note) {
 	}
 }
 
+// A Go shared library contains a note indicating which other Go shared libraries it
+// was linked against in an unmapped section.
+func testDepsNote(t *testing.T, f *elf.File, note *note) {
+	if note.section.Flags != 0 {
+		t.Errorf("package list section has flags %v", note.section.Flags)
+	}
+	if isOffsetLoaded(f, note.section.Offset) {
+		t.Errorf("package list section contained in PT_LOAD segment")
+	}
+	// libdep.so just links against the lib containing the runtime.
+	if note.desc != soname {
+		t.Errorf("incorrect dependency list %q", note.desc)
+	}
+}
+
 // The shared library contains notes with defined contents; see above.
 func TestNotes(t *testing.T) {
 	goCmd(t, "install", "-buildmode=shared", "-linkshared", "dep")
@@ -382,6 +397,7 @@ func TestNotes(t *testing.T) {
 	}
 	pkgListNoteFound := false
 	abiHashNoteFound := false
+	depsNoteFound := false
 	for _, note := range notes {
 		if note.name != "GO\x00\x00" {
 			continue
@@ -399,6 +415,12 @@ func TestNotes(t *testing.T) {
 			}
 			testABIHashNote(t, f, note)
 			abiHashNoteFound = true
+		case 3: // ELF_NOTE_GODEPS_TAG
+			if depsNoteFound {
+				t.Error("multiple abi hash notes")
+			}
+			testDepsNote(t, f, note)
+			depsNoteFound = true
 		}
 	}
 	if !pkgListNoteFound {
@@ -407,6 +429,19 @@ func TestNotes(t *testing.T) {
 	if !abiHashNoteFound {
 		t.Error("abi hash note not found")
 	}
+	if !depsNoteFound {
+		t.Error("deps note not found")
+	}
+}
+
+// Build a GOPATH package (dep) into a shared library that links against the goroot
+// runtime, another package (dep2) that links against the first, and and an
+// executable that links against dep2.
+func TestTwoGOPathShlibs(t *testing.T) {
+	goCmd(t, "install", "-buildmode=shared", "-linkshared", "dep")
+	goCmd(t, "install", "-buildmode=shared", "-linkshared", "dep2")
+	goCmd(t, "install", "-linkshared", "exe2")
+	run(t, "executable linked to GOPATH library", "./bin/exe2")
 }
 
 // Testing rebuilding of shared libraries when they are stale is a bit more
diff --git a/misc/cgo/testshared/src/dep2/dep2.go b/misc/cgo/testshared/src/dep2/dep2.go
new file mode 100644
index 0000000000..af8ad5e756
--- /dev/null
+++ b/misc/cgo/testshared/src/dep2/dep2.go
@@ -0,0 +1,9 @@
+package dep2
+
+import "dep"
+
+var W int = 1
+
+func G() int {
+	return dep.F() + 1
+}
diff --git a/misc/cgo/testshared/src/exe2/exe2.go b/misc/cgo/testshared/src/exe2/exe2.go
new file mode 100644
index 0000000000..acdb4ddcc5
--- /dev/null
+++ b/misc/cgo/testshared/src/exe2/exe2.go
@@ -0,0 +1,7 @@
+package main
+
+import "dep2"
+
+func main() {
+	dep2.W = dep2.G() + 1
+}
diff --git a/src/cmd/link/internal/ld/elf.go b/src/cmd/link/internal/ld/elf.go
index 83f10d39f6..68d21f415c 100644
--- a/src/cmd/link/internal/ld/elf.go
+++ b/src/cmd/link/internal/ld/elf.go
@@ -9,7 +9,9 @@ import (
 	"crypto/sha1"
 	"encoding/binary"
 	"fmt"
+	"path/filepath"
 	"sort"
+	"strings"
 )
 
 /*
@@ -1205,6 +1207,7 @@ func elfwritebuildinfo() int {
 const (
 	ELF_NOTE_GOPKGLIST_TAG = 1
 	ELF_NOTE_GOABIHASH_TAG = 2
+	ELF_NOTE_GODEPS_TAG    = 3
 )
 
 var ELF_NOTE_GO_NAME = []byte("GO\x00\x00")
@@ -1697,6 +1700,7 @@ func doelf() {
 		if Buildmode == BuildmodeShared {
 			Addstring(shstrtab, ".note.go.abihash")
 			Addstring(shstrtab, ".note.go.pkg-list")
+			Addstring(shstrtab, ".note.go.deps")
 		}
 	}
 
@@ -1904,6 +1908,11 @@ func doelf() {
 		}
 		addgonote(".note.go.abihash", ELF_NOTE_GOABIHASH_TAG, h.Sum([]byte{}))
 		addgonote(".note.go.pkg-list", ELF_NOTE_GOPKGLIST_TAG, []byte(pkglistfornote))
+		var deplist []string
+		for _, shlib := range Ctxt.Shlibs {
+			deplist = append(deplist, filepath.Base(shlib.Path))
+		}
+		addgonote(".note.go.deps", ELF_NOTE_GODEPS_TAG, []byte(strings.Join(deplist, "\n")))
 	}
 }
 
@@ -1976,6 +1985,8 @@ func Asmbelf(symo int64) {
 			sh = elfshname(".note.go.abihash")
 			sh.type_ = SHT_NOTE
 			sh.flags = SHF_ALLOC
+			sh = elfshname(".note.go.deps")
+			sh.type_ = SHT_NOTE
 		}
 		goto elfobj
 	}
diff --git a/src/cmd/link/internal/ld/go.go b/src/cmd/link/internal/ld/go.go
index 875b8d2e17..80a6c6ed7d 100644
--- a/src/cmd/link/internal/ld/go.go
+++ b/src/cmd/link/internal/ld/go.go
@@ -653,15 +653,14 @@ func deadcode() {
 	}
 
 	if Buildmode == BuildmodeShared {
-		// Mark all symbols as reachable when building a
-		// shared library.
+		// Mark all symbols defined in this library as reachable when
+		// building a shared library.
 		for s := Ctxt.Allsym; s != nil; s = s.Allsym {
-			if s.Type != 0 {
+			if s.Type != 0 && s.Type != obj.SDYNIMPORT {
 				mark(s)
 			}
 		}
-		mark(Linkrlookup(Ctxt, "main.main", 0))
-		mark(Linkrlookup(Ctxt, "main.init", 0))
+		markflood()
 	} else {
 		mark(Linklookup(Ctxt, INITENTRY, 0))
 		if Linkshared && Buildmode == BuildmodeExe {
diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go
index 26d722911b..8caac0f89c 100644
--- a/src/cmd/link/internal/ld/lib.go
+++ b/src/cmd/link/internal/ld/lib.go
@@ -983,15 +983,35 @@ func hostlink() {
 	argv = append(argv, fmt.Sprintf("%s/go.o", tmpdir))
 
 	if Linkshared {
-		for _, shlib := range Ctxt.Shlibs {
-			dir, base := filepath.Split(shlib.Path)
-			argv = append(argv, "-L"+dir)
-			if !rpath.set {
-				argv = append(argv, "-Wl,-rpath="+dir)
+		seenDirs := make(map[string]bool)
+		seenLibs := make(map[string]bool)
+		addshlib := func(path string) {
+			dir, base := filepath.Split(path)
+			if !seenDirs[dir] {
+				argv = append(argv, "-L"+dir)
+				if !rpath.set {
+					argv = append(argv, "-Wl,-rpath="+dir)
+				}
+				seenDirs[dir] = true
 			}
 			base = strings.TrimSuffix(base, ".so")
 			base = strings.TrimPrefix(base, "lib")
-			argv = append(argv, "-l"+base)
+			if !seenLibs[base] {
+				argv = append(argv, "-l"+base)
+				seenLibs[base] = true
+			}
+		}
+		for _, shlib := range Ctxt.Shlibs {
+			addshlib(shlib.Path)
+			for _, dep := range shlib.Deps {
+				if dep == "" {
+					continue
+				}
+				libpath := findshlib(dep)
+				if libpath != "" {
+					addshlib(libpath)
+				}
+			}
 		}
 	}
 
@@ -1214,18 +1234,20 @@ func readnote(f *elf.File, name []byte, typ int32) ([]byte, error) {
 	return nil, nil
 }
 
-func ldshlibsyms(shlib string) {
-	found := false
-	libpath := ""
+func findshlib(shlib string) string {
 	for _, libdir := range Ctxt.Libdir {
-		libpath = filepath.Join(libdir, shlib)
+		libpath := filepath.Join(libdir, shlib)
 		if _, err := os.Stat(libpath); err == nil {
-			found = true
-			break
+			return libpath
 		}
 	}
-	if !found {
-		Diag("cannot find shared library: %s", shlib)
+	Diag("cannot find shared library: %s", shlib)
+	return ""
+}
+
+func ldshlibsyms(shlib string) {
+	libpath := findshlib(shlib)
+	if libpath == "" {
 		return
 	}
 	for _, processedlib := range Ctxt.Shlibs {
@@ -1251,6 +1273,13 @@ func ldshlibsyms(shlib string) {
 		return
 	}
 
+	depsbytes, err := readnote(f, ELF_NOTE_GO_NAME, ELF_NOTE_GODEPS_TAG)
+	if err != nil {
+		Diag("cannot read dep list from shared library %s: %v", libpath, err)
+		return
+	}
+	deps := strings.Split(string(depsbytes), "\n")
+
 	syms, err := f.Symbols()
 	if err != nil {
 		Diag("cannot read symbols from shared library: %s", libpath)
@@ -1272,12 +1301,6 @@ func ldshlibsyms(shlib string) {
 		if elf.ST_TYPE(s.Info) == elf.STT_NOTYPE || elf.ST_TYPE(s.Info) == elf.STT_SECTION {
 			continue
 		}
-		if s.Section == elf.SHN_UNDEF {
-			continue
-		}
-		if strings.HasPrefix(s.Name, "_") {
-			continue
-		}
 		if strings.HasPrefix(s.Name, "runtime.gcbits.") {
 			gcmasks[s.Value] = readelfsymboldata(f, &s)
 		}
@@ -1285,7 +1308,7 @@ func ldshlibsyms(shlib string) {
 			continue
 		}
 		lsym := Linklookup(Ctxt, s.Name, 0)
-		if lsym.Type != 0 && lsym.Dupok == 0 {
+		if lsym.Type != 0 && lsym.Type != obj.SDYNIMPORT && lsym.Dupok == 0 {
 			Diag(
 				"Found duplicate symbol %s reading from %s, first found in %s",
 				s.Name, shlib, lsym.File)
@@ -1342,7 +1365,7 @@ func ldshlibsyms(shlib string) {
 		Ctxt.Etextp = last
 	}
 
-	Ctxt.Shlibs = append(Ctxt.Shlibs, Shlib{Path: libpath, Hash: hash})
+	Ctxt.Shlibs = append(Ctxt.Shlibs, Shlib{Path: libpath, Hash: hash, Deps: deps})
 }
 
 func mywhatsys() {
diff --git a/src/cmd/link/internal/ld/link.go b/src/cmd/link/internal/ld/link.go
index 4b034a4e81..a288148a5a 100644
--- a/src/cmd/link/internal/ld/link.go
+++ b/src/cmd/link/internal/ld/link.go
@@ -117,6 +117,7 @@ type Auto struct {
 type Shlib struct {
 	Path string
 	Hash []byte
+	Deps []string
 }
 
 type Link struct {