Add test of undefined return address.
Add a specific test that __libc_init is the last frame in a stack
when run on device. In addition, it verifies that the return address
register is marked as undefined given the unwind.
Bug: 140008396
Test: New unit test passes on arm/arm64 (taimen device).
Test: New unit test passes on x86 (cuttlefish).
Test: New unit test passes on x86_64 (modified bionic/tests/run-on-host.sh)
Change-Id: Iefc151a7dbf52ab083c2bb78bad3d38b4e9e1254
diff --git a/libunwindstack/Android.bp b/libunwindstack/Android.bp
index 73237e6..14246ae 100644
--- a/libunwindstack/Android.bp
+++ b/libunwindstack/Android.bp
@@ -211,6 +211,7 @@
"tests/UnwindOfflineTest.cpp",
"tests/UnwindTest.cpp",
"tests/UnwinderTest.cpp",
+ "tests/VerifyBionicTerminationTest.cpp",
],
cflags: [
diff --git a/libunwindstack/Unwinder.cpp b/libunwindstack/Unwinder.cpp
index 7556482..0b9b85c 100644
--- a/libunwindstack/Unwinder.cpp
+++ b/libunwindstack/Unwinder.cpp
@@ -309,7 +309,7 @@
}
}
-std::string Unwinder::FormatFrame(const FrameData& frame) {
+std::string Unwinder::FormatFrame(const FrameData& frame) const {
std::string data;
if (regs_->Is32Bit()) {
data += android::base::StringPrintf(" #%02zu pc %08" PRIx64, frame.num, frame.rel_pc);
@@ -355,7 +355,7 @@
return data;
}
-std::string Unwinder::FormatFrame(size_t frame_num) {
+std::string Unwinder::FormatFrame(size_t frame_num) const {
if (frame_num >= frames_.size()) {
return "";
}
diff --git a/libunwindstack/include/unwindstack/Unwinder.h b/libunwindstack/include/unwindstack/Unwinder.h
index 52b3578..11ad9de 100644
--- a/libunwindstack/include/unwindstack/Unwinder.h
+++ b/libunwindstack/include/unwindstack/Unwinder.h
@@ -77,7 +77,7 @@
void Unwind(const std::vector<std::string>* initial_map_names_to_skip = nullptr,
const std::vector<std::string>* map_suffixes_to_ignore = nullptr);
- size_t NumFrames() { return frames_.size(); }
+ size_t NumFrames() const { return frames_.size(); }
const std::vector<FrameData>& frames() { return frames_; }
@@ -87,8 +87,8 @@
return frames;
}
- std::string FormatFrame(size_t frame_num);
- std::string FormatFrame(const FrameData& frame);
+ std::string FormatFrame(size_t frame_num) const;
+ std::string FormatFrame(const FrameData& frame) const;
void SetJitDebug(JitDebug* jit_debug, ArchEnum arch);
diff --git a/libunwindstack/tests/VerifyBionicTerminationTest.cpp b/libunwindstack/tests/VerifyBionicTerminationTest.cpp
new file mode 100644
index 0000000..6a3e91a
--- /dev/null
+++ b/libunwindstack/tests/VerifyBionicTerminationTest.cpp
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#define _GNU_SOURCE 1
+#include <stdint.h>
+#include <string.h>
+
+#include <string>
+
+#if defined(__BIONIC__)
+
+#include <gtest/gtest.h>
+
+#include <unwindstack/DwarfSection.h>
+#include <unwindstack/Elf.h>
+#include <unwindstack/ElfInterface.h>
+#include <unwindstack/Regs.h>
+#include <unwindstack/RegsGetLocal.h>
+#include <unwindstack/Unwinder.h>
+
+// This test is specific to bionic to verify that __libc_init is
+// properly setting the return address to undefined so that the
+// unwind properly terminates.
+
+namespace unwindstack {
+
+static std::string DumpFrames(const UnwinderFromPid& unwinder) {
+ std::string unwind;
+ for (size_t i = 0; i < unwinder.NumFrames(); i++) {
+ unwind += unwinder.FormatFrame(i) + '\n';
+ }
+ return unwind;
+}
+
+static DwarfLocationEnum GetReturnAddressLocation(uint64_t rel_pc, DwarfSection* section) {
+ if (section == nullptr) {
+ return DWARF_LOCATION_INVALID;
+ }
+
+ const DwarfFde* fde = section->GetFdeFromPc(rel_pc);
+ if (fde == nullptr || fde->cie == nullptr) {
+ return DWARF_LOCATION_INVALID;
+ }
+ dwarf_loc_regs_t regs;
+ if (!section->GetCfaLocationInfo(rel_pc, fde, ®s)) {
+ return DWARF_LOCATION_INVALID;
+ }
+
+ auto reg_entry = regs.find(fde->cie->return_address_register);
+ if (reg_entry == regs.end()) {
+ return DWARF_LOCATION_INVALID;
+ }
+ return reg_entry->second.type;
+}
+
+static void VerifyReturnAddress(const FrameData& frame) {
+ // Now go and find information about the register data and verify that the relative pc results in
+ // an undefined register.
+ Elf elf(Memory::CreateFileMemory(frame.map_name, 0).release());
+ ASSERT_TRUE(elf.Init()) << "Failed to init elf object from " << frame.map_name;
+ ASSERT_TRUE(elf.valid()) << "Elf " << frame.map_name << " is not valid.";
+ ElfInterface* interface = elf.interface();
+
+ // Only check the eh_frame and the debug_frame since the undefined register
+ // is set using a cfi directive.
+ // Check debug_frame first, then eh_frame since debug_frame always
+ // contains the most specific data.
+ DwarfLocationEnum location = GetReturnAddressLocation(frame.rel_pc, interface->debug_frame());
+ if (location == DWARF_LOCATION_UNDEFINED) {
+ return;
+ }
+
+ location = GetReturnAddressLocation(frame.rel_pc, interface->eh_frame());
+ ASSERT_EQ(DWARF_LOCATION_UNDEFINED, location);
+}
+
+// This test assumes that it starts from the main thread, and that the
+// libc.so on device will include symbols so that function names can
+// be resolved.
+TEST(VerifyBionicTermination, local_terminate) {
+ std::unique_ptr<Regs> regs(Regs::CreateFromLocal());
+
+ UnwinderFromPid unwinder(512, getpid());
+ ASSERT_TRUE(unwinder.Init(regs->Arch()));
+ unwinder.SetRegs(regs.get());
+
+ RegsGetLocal(regs.get());
+ unwinder.Unwind();
+ ASSERT_LT(0U, unwinder.NumFrames());
+
+ SCOPED_TRACE(DumpFrames(unwinder));
+
+ // Look for the frame that includes __libc_init, there should only
+ // be one and it should be the last.
+ bool found = false;
+ const std::vector<FrameData>& frames = unwinder.frames();
+ for (size_t i = 0; i < unwinder.NumFrames(); i++) {
+ const FrameData& frame = frames[i];
+ if (frame.function_name == "__libc_init" && !frame.map_name.empty() &&
+ std::string("libc.so") == basename(frame.map_name.c_str())) {
+ ASSERT_EQ(unwinder.NumFrames(), i + 1) << "__libc_init is not last frame.";
+ ASSERT_NO_FATAL_FAILURE(VerifyReturnAddress(frame));
+ found = true;
+ }
+ }
+ ASSERT_TRUE(found) << "Unable to find libc.so:__libc_init frame\n";
+}
+
+} // namespace unwindstack
+
+#endif