Fix the host bionic linker check; add tests
Gold uses two PT_LOAD programs: RX, RW
LLD is using three PT_LOAD programs: R, RX, RW
All non-static host bionic executables are linked with LLD, as it's
required in order to embed the linker. The dynamic linker is considered
a static executable for this definition.
When the linker had been built with Gold, we inserted the the RX&RW
loads in the middle of the executable's readonly load, splitting the R
load into two. When this happened, all of the linker's loads existed 1:1
in the final executable.
Now that the linker is built with LLD, we're inserting the loads into
the same place, but LLD merges the first part of the executable's R load
with the linker's R load, so there's not a 1:1 matching.
So just make sure that all of the linker's loads are contained within
the executable's loads (and with the appropriate flags).
Test: m blueprint_tools (runs new tests)
Test: build host bionic binaries
Change-Id: If7868d2ab8980d27ba5ab8994fefe0d6142f215a
diff --git a/cmd/host_bionic_inject/Android.bp b/cmd/host_bionic_inject/Android.bp
index acce683..5994103 100644
--- a/cmd/host_bionic_inject/Android.bp
+++ b/cmd/host_bionic_inject/Android.bp
@@ -16,4 +16,5 @@
name: "host_bionic_inject",
deps: ["soong-symbol_inject"],
srcs: ["host_bionic_inject.go"],
+ testSrcs: ["host_bionic_inject_test.go"],
}
diff --git a/cmd/host_bionic_inject/host_bionic_inject.go b/cmd/host_bionic_inject/host_bionic_inject.go
index 0dabbba..f7163d7 100644
--- a/cmd/host_bionic_inject/host_bionic_inject.go
+++ b/cmd/host_bionic_inject/host_bionic_inject.go
@@ -136,33 +136,28 @@
continue
}
+ laddr := lprog.Vaddr + dlwrap_linker_offset.Value
+
found := false
- for j, prog := range file.Progs {
+ for _, prog := range file.Progs {
if prog.Type != elf.PT_LOAD {
continue
}
- if lprog.Vaddr+dlwrap_linker_offset.Value != prog.Vaddr {
+ if laddr < prog.Vaddr || laddr > prog.Vaddr+prog.Memsz {
continue
}
found = true
- if lprog.Memsz != prog.Memsz {
- return fmt.Errorf("Linker prog %d (0x%x) memsz (0x%x) does not match (0x%x)",
- i, lprog.Vaddr, lprog.Memsz, prog.Memsz)
- }
-
- // The linker shouldn't be using BSS, since only one
- // BSS section is supported per ELF file.
- if prog.Memsz != prog.Filesz {
- return fmt.Errorf("Embedded prog %d (0x%x) memsz (0x%x) does not match filesz (0x%x)",
- j, prog.Vaddr, prog.Memsz, prog.Filesz)
- }
-
if lprog.Flags != prog.Flags {
return fmt.Errorf("Linker prog %d (0x%x) flags (%s) do not match (%s)",
i, lprog.Vaddr, lprog.Flags, prog.Flags)
}
+
+ if laddr+lprog.Memsz > prog.Vaddr+prog.Filesz {
+ return fmt.Errorf("Linker prog %d (0x%x) not fully present (0x%x > 0x%x)",
+ i, lprog.Vaddr, laddr+lprog.Memsz, prog.Vaddr+prog.Filesz)
+ }
}
if !found {
return fmt.Errorf("Linker prog %d (0x%x) not found at offset 0x%x",
diff --git a/cmd/host_bionic_inject/host_bionic_inject_test.go b/cmd/host_bionic_inject/host_bionic_inject_test.go
new file mode 100644
index 0000000..b415b34
--- /dev/null
+++ b/cmd/host_bionic_inject/host_bionic_inject_test.go
@@ -0,0 +1,146 @@
+// Copyright 2018 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+ "debug/elf"
+ "fmt"
+ "testing"
+)
+
+// prog is a shortcut to fill out a elf.Prog structure
+func prog(flags elf.ProgFlag, offset, addr, filesz, memsz uint64) *elf.Prog {
+ return &elf.Prog{
+ ProgHeader: elf.ProgHeader{
+ Type: elf.PT_LOAD,
+ Flags: flags,
+ Off: offset,
+ Vaddr: addr,
+ Paddr: addr,
+ Filesz: filesz,
+ Memsz: memsz,
+ },
+ }
+}
+
+// linkerGold returns an example elf.File from a linker binary that was linked
+// with gold.
+func linkerGold() *elf.File {
+ return &elf.File{
+ Progs: []*elf.Prog{
+ prog(elf.PF_R|elf.PF_X, 0, 0, 0xd0fac, 0xd0fac),
+ prog(elf.PF_R|elf.PF_W, 0xd1050, 0xd2050, 0x6890, 0xd88c),
+ },
+ }
+}
+
+// fileGold returns an example elf binary with a properly embedded linker. The
+// embedded linker was the one returned by linkerGold.
+func fileGold() *elf.File {
+ return &elf.File{
+ Progs: []*elf.Prog{
+ prog(elf.PF_R, 0, 0, 0x2e0, 0x2e0),
+ prog(elf.PF_R|elf.PF_X, 0x1000, 0x1000, 0xd0fac, 0xd0fac),
+ prog(elf.PF_R|elf.PF_W, 0xd2050, 0xd3050, 0xd88c, 0xd88c),
+ prog(elf.PF_R, 0xe0000, 0xe1000, 0x10e4, 0x10e4),
+ prog(elf.PF_R|elf.PF_X, 0xe2000, 0xe3000, 0x1360, 0x1360),
+ prog(elf.PF_R|elf.PF_W, 0xe4000, 0xe5000, 0x1358, 0x1358),
+ },
+ }
+}
+
+// linkerLld returns an example elf.File from a linker binary that was linked
+// with lld.
+func linkerLld() *elf.File {
+ return &elf.File{
+ Progs: []*elf.Prog{
+ prog(elf.PF_R, 0, 0, 0x3c944, 0x3c944),
+ prog(elf.PF_R|elf.PF_X, 0x3d000, 0x3d000, 0x946fa, 0x946fa),
+ prog(elf.PF_R|elf.PF_W, 0xd2000, 0xd2000, 0x7450, 0xf778),
+ },
+ }
+}
+
+// fileGold returns an example elf binary with a properly embedded linker. The
+// embedded linker was the one returned by linkerLld.
+func fileLld() *elf.File {
+ return &elf.File{
+ Progs: []*elf.Prog{
+ prog(elf.PF_R, 0, 0, 0x3d944, 0x3d944),
+ prog(elf.PF_R|elf.PF_X, 0x3e000, 0x3e000, 0x946fa, 0x946fa),
+ prog(elf.PF_R|elf.PF_W, 0xd3000, 0xd3000, 0xf778, 0xf778),
+ prog(elf.PF_R, 0xe3000, 0xe3000, 0x10e4, 0x10e4),
+ prog(elf.PF_R|elf.PF_X, 0xe5000, 0xe5000, 0x1360, 0x1360),
+ prog(elf.PF_R|elf.PF_W, 0xe7000, 0xe7000, 0x1358, 0x1358),
+ },
+ }
+}
+
+// linkerOffset returns the symbol representing the linker offset used by both
+// fileGold and fileLld
+func linkerOffset() []elf.Symbol {
+ return []elf.Symbol{
+ elf.Symbol{
+ Name: "__dlwrap_linker_offset",
+ Value: 0x1000,
+ },
+ }
+}
+
+func TestCheckLinker(t *testing.T) {
+ cases := []struct {
+ name string
+ err error
+ file func() *elf.File
+ linker func() *elf.File
+ }{
+ {
+ name: "good gold-linked linker",
+ file: fileGold,
+ linker: linkerGold,
+ },
+ {
+ name: "good lld-linked linker",
+ file: fileLld,
+ linker: linkerLld,
+ },
+ {
+ name: "truncated RO section",
+ err: fmt.Errorf("Linker prog 0 (0x0) not fully present (0x3d944 > 0x3d943)"),
+ file: func() *elf.File {
+ f := fileLld()
+ f.Progs[0].Filesz -= 1
+ f.Progs[0].Memsz -= 1
+ return f
+ },
+ linker: linkerLld,
+ },
+ }
+
+ for _, tc := range cases {
+ t.Run(tc.name, func(t *testing.T) {
+ err := checkLinker(tc.file(), tc.linker(), linkerOffset())
+ if tc.err == nil {
+ if err != nil {
+ t.Fatalf("No error expected, but got: %v", err)
+ }
+ } else if err == nil {
+ t.Fatalf("Returned no error, but wanted: %v", tc.err)
+ } else if err.Error() != tc.err.Error() {
+ t.Fatalf("Different error found:\nwant: %v\n got: %v", tc.err, err)
+ }
+ })
+ }
+}