9 files changed, 437 insertions, 62 deletions

diff --git a/libunwindstack/DwarfSection.cpp b/libunwindstack/DwarfSection.cpp
index 9e2a3cda7..bf86e6e66 100644
--- a/libunwindstack/DwarfSection.cpp
+++ b/libunwindstack/DwarfSection.cpp
@@ -465,13 +465,9 @@ bool DwarfSectionImpl<AddressType>::EvalRegister(const DwarfLocation* loc, uint3
         eval_info->return_address_undefined = true;
       }
       break;
-    case DWARF_LOCATION_PSEUDO_REGISTER: {
-      if (!eval_info->regs_info.regs->SetPseudoRegister(reg, loc->values[0])) {
-        last_error_.code = DWARF_ERROR_ILLEGAL_VALUE;
-        return false;
-      }
-      break;
-    }
+    case DWARF_LOCATION_PSEUDO_REGISTER:
+      last_error_.code = DWARF_ERROR_ILLEGAL_VALUE;
+      return false;
     default:
       break;
   }
@@ -543,11 +539,15 @@ bool DwarfSectionImpl<AddressType>::Eval(const DwarfCie* cie, Memory* regular_me
         // Skip this unknown register.
         continue;
       }
-    }
-
-    reg_ptr = eval_info.regs_info.Save(reg);
-    if (!EvalRegister(&entry.second, reg, reg_ptr, &eval_info)) {
-      return false;
+      if (!eval_info.regs_info.regs->SetPseudoRegister(reg, entry.second.values[0])) {
+        last_error_.code = DWARF_ERROR_ILLEGAL_VALUE;
+        return false;
+      }
+    } else {
+      reg_ptr = eval_info.regs_info.Save(reg);
+      if (!EvalRegister(&entry.second, reg, reg_ptr, &eval_info)) {
+        return false;
+      }
     }
   }
 
diff --git a/libunwindstack/RegsX86_64.cpp b/libunwindstack/RegsX86_64.cpp
index c9e245d2f..26d9f6578 100644
--- a/libunwindstack/RegsX86_64.cpp
+++ b/libunwindstack/RegsX86_64.cpp
@@ -141,15 +141,14 @@ bool RegsX86_64::StepIfSignalHandler(uint64_t elf_offset, Elf* elf, Memory* proc
     return false;
   }
 
-  uint16_t data2;
-  if (!elf_memory->ReadFully(elf_offset + 8, &data2, sizeof(data2)) || data2 != 0x0f05) {
+  uint8_t data2;
+  if (!elf_memory->ReadFully(elf_offset + 8, &data2, sizeof(data2)) || data2 != 0x05) {
     return false;
   }
 
   // __restore_rt:
   // 0x48 0xc7 0xc0 0x0f 0x00 0x00 0x00   mov $0xf,%rax
   // 0x0f 0x05                            syscall
-  // 0x0f                                 nopl 0x0($rax)
 
   // Read the mcontext data from the stack.
   // sp points to the ucontext data structure, read only the mcontext part.
diff --git a/libunwindstack/Unwinder.cpp b/libunwindstack/Unwinder.cpp
index 2d867cd5e..57806c157 100644
--- a/libunwindstack/Unwinder.cpp
+++ b/libunwindstack/Unwinder.cpp
@@ -75,6 +75,7 @@ void Unwinder::FillInDexFrame() {
     frame->rel_pc = dex_pc - info->start;
   } else {
     frame->rel_pc = dex_pc;
+    warnings_ |= WARNING_DEX_PC_NOT_IN_MAP;
     return;
   }
 
@@ -142,6 +143,7 @@ static bool ShouldStop(const std::vector<std::string>* map_suffixes_to_ignore,
 void Unwinder::Unwind(const std::vector<std::string>* initial_map_names_to_skip,
                       const std::vector<std::string>* map_suffixes_to_ignore) {
   frames_.clear();
+  warnings_ = WARNING_NONE;
   last_error_.code = ERROR_NONE;
   last_error_.address = 0;
   elf_from_memory_not_file_ = false;
@@ -395,18 +397,20 @@ bool UnwinderFromPid::Init(ArchEnum arch) {
   return true;
 }
 
-FrameData Unwinder::BuildFrameFromPcOnly(uint64_t pc) {
+FrameData Unwinder::BuildFrameFromPcOnly(uint64_t pc, ArchEnum arch, Maps* maps,
+                                         JitDebug* jit_debug,
+                                         std::shared_ptr<Memory> process_memory,
+                                         bool resolve_names) {
   FrameData frame;
 
-  Maps* maps = GetMaps();
   MapInfo* map_info = maps->Find(pc);
-  if (!map_info) {
+  if (map_info == nullptr || arch == ARCH_UNKNOWN) {
+    frame.pc = pc;
     frame.rel_pc = pc;
     return frame;
   }
 
-  ArchEnum arch = Regs::CurrentArch();
-  Elf* elf = map_info->GetElf(GetProcessMemory(), arch);
+  Elf* elf = map_info->GetElf(process_memory, arch);
 
   uint64_t relative_pc = elf->GetRelPc(pc, map_info);
 
@@ -416,10 +420,9 @@ FrameData Unwinder::BuildFrameFromPcOnly(uint64_t pc) {
   uint64_t debug_pc = relative_pc;
 
   // If we don't have a valid ELF file, check the JIT.
-  if (!elf->valid()) {
-    JitDebug jit_debug(GetProcessMemory());
+  if (!elf->valid() && jit_debug != nullptr) {
     uint64_t jit_pc = pc - pc_adjustment;
-    Elf* jit_elf = jit_debug.GetElf(maps, jit_pc);
+    Elf* jit_elf = jit_debug->GetElf(maps, jit_pc);
     if (jit_elf != nullptr) {
       debug_pc = jit_pc;
       elf = jit_elf;
@@ -437,12 +440,17 @@ FrameData Unwinder::BuildFrameFromPcOnly(uint64_t pc) {
   frame.map_flags = map_info->flags;
   frame.map_load_bias = elf->GetLoadBias();
 
-  if (!resolve_names_ ||
-      !elf->GetFunctionName(relative_pc, &frame.function_name, &frame.function_offset)) {
+  if (!resolve_names ||
+      !elf->GetFunctionName(debug_pc, &frame.function_name, &frame.function_offset)) {
     frame.function_name = "";
     frame.function_offset = 0;
   }
   return frame;
 }
 
+FrameData Unwinder::BuildFrameFromPcOnly(uint64_t pc) {
+  return BuildFrameFromPcOnly(pc, regs_ ? regs_->Arch() : ARCH_UNKNOWN, maps_, jit_debug_,
+                              process_memory_, resolve_names_);
+}
+
 }  // namespace unwindstack
diff --git a/libunwindstack/include/unwindstack/Error.h b/libunwindstack/include/unwindstack/Error.h
index 72ec4547f..66fefe76d 100644
--- a/libunwindstack/include/unwindstack/Error.h
+++ b/libunwindstack/include/unwindstack/Error.h
@@ -21,6 +21,13 @@
 
 namespace unwindstack {
 
+// A bit map of warnings, multiple warnings can be set at the same time.
+enum WarningCode : uint64_t {
+  WARNING_NONE = 0,
+  WARNING_DEX_PC_NOT_IN_MAP = 0x1,  // A dex pc was found, but it doesn't exist
+                                    // in any valid map.
+};
+
 enum ErrorCode : uint8_t {
   ERROR_NONE,                 // No error.
   ERROR_MEMORY_INVALID,       // Memory read failed.
diff --git a/libunwindstack/include/unwindstack/Unwinder.h b/libunwindstack/include/unwindstack/Unwinder.h
index 4d49f236a..3df8aadfd 100644
--- a/libunwindstack/include/unwindstack/Unwinder.h
+++ b/libunwindstack/include/unwindstack/Unwinder.h
@@ -113,12 +113,15 @@ class Unwinder {
 
   ErrorCode LastErrorCode() { return last_error_.code; }
   uint64_t LastErrorAddress() { return last_error_.address; }
+  uint64_t warnings() { return warnings_; }
 
   // Builds a frame for symbolization using the maps from this unwinder. The
   // constructed frame contains just enough information to be used to symbolize
   // frames collected by frame-pointer unwinding that's done outside of
   // libunwindstack. This is used by tombstoned to symbolize frame pointer-based
   // stack traces that are collected by tools such as GWP-ASan and MTE.
+  static FrameData BuildFrameFromPcOnly(uint64_t pc, ArchEnum arch, Maps* maps, JitDebug* jit_debug,
+                                        std::shared_ptr<Memory> process_memory, bool resolve_names);
   FrameData BuildFrameFromPcOnly(uint64_t pc);
 
  protected:
@@ -141,6 +144,7 @@ class Unwinder {
   // file. This is only true if there is an actual file backing up the elf.
   bool elf_from_memory_not_file_ = false;
   ErrorData last_error_;
+  uint64_t warnings_;
 };
 
 class UnwinderFromPid : public Unwinder {
diff --git a/libunwindstack/tests/DwarfSectionImplTest.cpp b/libunwindstack/tests/DwarfSectionImplTest.cpp
index d57cd339d..a08a8d070 100644
--- a/libunwindstack/tests/DwarfSectionImplTest.cpp
+++ b/libunwindstack/tests/DwarfSectionImplTest.cpp
@@ -492,6 +492,40 @@ TYPED_TEST_P(DwarfSectionImplTest, Eval_reg_val_expr) {
   EXPECT_EQ(0x80000000U, regs.pc());
 }
 
+TYPED_TEST_P(DwarfSectionImplTest, Eval_pseudo_register_invalid) {
+  DwarfCie cie{.return_address_register = 5};
+  RegsImplFake<TypeParam> regs(10);
+  regs.set_pseudo_reg(11);
+  dwarf_loc_regs_t loc_regs;
+
+  loc_regs[CFA_REG] = DwarfLocation{DWARF_LOCATION_REGISTER, {8, 0}};
+  loc_regs[1] = DwarfLocation{DWARF_LOCATION_PSEUDO_REGISTER, {20, 0}};
+  bool finished;
+  ASSERT_FALSE(this->section_->Eval(&cie, &this->memory_, loc_regs, &regs, &finished));
+  EXPECT_EQ(DWARF_ERROR_ILLEGAL_VALUE, this->section_->LastErrorCode());
+
+  loc_regs.clear();
+  loc_regs[CFA_REG] = DwarfLocation{DWARF_LOCATION_REGISTER, {8, 0}};
+  loc_regs[12] = DwarfLocation{DWARF_LOCATION_PSEUDO_REGISTER, {20, 0}};
+  ASSERT_FALSE(this->section_->Eval(&cie, &this->memory_, loc_regs, &regs, &finished));
+  EXPECT_EQ(DWARF_ERROR_ILLEGAL_VALUE, this->section_->LastErrorCode());
+}
+
+TYPED_TEST_P(DwarfSectionImplTest, Eval_pseudo_register) {
+  DwarfCie cie{.return_address_register = 5};
+  RegsImplFake<TypeParam> regs(10);
+  regs.set_pseudo_reg(11);
+  dwarf_loc_regs_t loc_regs;
+
+  loc_regs[CFA_REG] = DwarfLocation{DWARF_LOCATION_REGISTER, {8, 0}};
+  loc_regs[11] = DwarfLocation{DWARF_LOCATION_PSEUDO_REGISTER, {20, 0}};
+  bool finished;
+  ASSERT_TRUE(this->section_->Eval(&cie, &this->memory_, loc_regs, &regs, &finished));
+  uint64_t pseudo_value = 0;
+  ASSERT_TRUE(regs.GetPseudoRegister(11, &pseudo_value));
+  EXPECT_EQ(20U, pseudo_value);
+}
+
 TYPED_TEST_P(DwarfSectionImplTest, GetCfaLocationInfo_cie_not_cached) {
   DwarfCie cie{};
   cie.cfa_instructions_offset = 0x3000;
@@ -581,6 +615,7 @@ REGISTER_TYPED_TEST_SUITE_P(DwarfSectionImplTest, GetCieFromOffset_fail_should_n
                             Eval_invalid_register, Eval_different_reg_locations,
                             Eval_return_address_undefined, Eval_pc_zero, Eval_return_address,
                             Eval_ignore_large_reg_loc, Eval_reg_expr, Eval_reg_val_expr,
+                            Eval_pseudo_register_invalid, Eval_pseudo_register,
                             GetCfaLocationInfo_cie_not_cached, GetCfaLocationInfo_cie_cached, Log);
 
 typedef ::testing::Types<uint32_t, uint64_t> DwarfSectionImplTestTypes;
diff --git a/libunwindstack/tests/RegsFake.h b/libunwindstack/tests/RegsFake.h
index 75fc9d02d..f67d7dc61 100644
--- a/libunwindstack/tests/RegsFake.h
+++ b/libunwindstack/tests/RegsFake.h
@@ -83,15 +83,33 @@ class RegsImplFake : public RegsImpl<TypeParam> {
   uint64_t sp() override { return fake_sp_; }
   void set_pc(uint64_t pc) override { fake_pc_ = pc; }
   void set_sp(uint64_t sp) override { fake_sp_ = sp; }
+  void set_pseudo_reg(uint64_t reg) { fake_pseudo_reg_ = reg; }
 
   bool SetPcFromReturnAddress(Memory*) override { return false; }
   bool StepIfSignalHandler(uint64_t, Elf*, Memory*) override { return false; }
 
+  bool SetPseudoRegister(uint16_t reg, uint64_t value) override {
+    if (fake_pseudo_reg_ != reg) {
+      return false;
+    }
+    fake_pseudo_reg_value_ = value;
+    return true;
+  }
+  bool GetPseudoRegister(uint16_t reg, uint64_t* value) override {
+    if (fake_pseudo_reg_ != reg) {
+      return false;
+    }
+    *value = fake_pseudo_reg_value_;
+    return true;
+  }
+
   Regs* Clone() override { return nullptr; }
 
  private:
   uint64_t fake_pc_ = 0;
   uint64_t fake_sp_ = 0;
+  uint16_t fake_pseudo_reg_ = 0;
+  uint64_t fake_pseudo_reg_value_ = 0;
 };
 
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/UnwinderTest.cpp b/libunwindstack/tests/UnwinderTest.cpp
index dd33aa9d7..915f24884 100644
--- a/libunwindstack/tests/UnwinderTest.cpp
+++ b/libunwindstack/tests/UnwinderTest.cpp
@@ -37,6 +37,7 @@
 #include <unwindstack/Unwinder.h>
 
 #include "ElfFake.h"
+#include "ElfTestUtils.h"
 #include "MemoryFake.h"
 #include "RegsFake.h"
 
@@ -44,23 +45,31 @@ namespace unwindstack {
 
 class UnwinderTest : public ::testing::Test {
  protected:
-  static void AddMapInfo(uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
-                         const char* name, Elf* elf = nullptr) {
+  static MapInfo* AddMapInfo(uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
+                             const char* name, Elf* elf = nullptr) {
     std::string str_name(name);
     maps_->Add(start, end, offset, flags, name, static_cast<uint64_t>(-1));
+    MapInfo* map_info = maps_->Find(start);
     if (elf != nullptr) {
-      const auto& map_info = *--maps_->end();
       map_info->elf.reset(elf);
     }
+    return map_info;
   }
 
   static void SetUpTestSuite() {
     maps_.reset(new Maps);
 
-    ElfFake* elf = new ElfFake(new MemoryFake);
-    ElfInterfaceFake* interface_fake = new ElfInterfaceFake(nullptr);
-    interface_fake->FakeSetBuildID("FAKE");
-    elf->FakeSetInterface(interface_fake);
+    memory_ = new MemoryFake;
+    process_memory_.reset(memory_);
+
+    ElfFake* elf;
+    ElfInterfaceFake* interface;
+    MapInfo* map_info;
+
+    elf = new ElfFake(new MemoryFake);
+    interface = new ElfInterfaceFake(nullptr);
+    interface->FakeSetBuildID("FAKE");
+    elf->FakeSetInterface(interface);
     AddMapInfo(0x1000, 0x8000, 0, PROT_READ | PROT_WRITE, "/system/fake/libc.so", elf);
 
     AddMapInfo(0x10000, 0x12000, 0, PROT_READ | PROT_WRITE, "[stack]");
@@ -81,19 +90,17 @@ class UnwinderTest : public ::testing::Test {
     AddMapInfo(0x33000, 0x34000, 0, PROT_READ | PROT_WRITE, "/fake/compressed.so", elf);
 
     elf = new ElfFake(new MemoryFake);
-    ElfInterfaceFake* interface = new ElfInterfaceFake(nullptr);
+    interface = new ElfInterfaceFake(nullptr);
     interface->FakeSetSoname("lib_fake.so");
     elf->FakeSetInterface(interface);
-    AddMapInfo(0x43000, 0x44000, 0x1d000, PROT_READ | PROT_WRITE, "/fake/fake.apk", elf);
-    MapInfo* map_info = maps_->Find(0x43000);
-    ASSERT_TRUE(map_info != nullptr);
+    map_info = AddMapInfo(0x43000, 0x44000, 0x1d000, PROT_READ | PROT_WRITE, "/fake/fake.apk", elf);
     map_info->elf_start_offset = 0x1d000;
 
     AddMapInfo(0x53000, 0x54000, 0, PROT_READ | PROT_WRITE, "/fake/fake.oat");
 
-    AddMapInfo(0xa3000, 0xa4000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "/fake/fake.vdex");
-    const auto& info = *--maps_->end();
-    info->load_bias = 0;
+    map_info =
+        AddMapInfo(0xa3000, 0xa4000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "/fake/fake.vdex");
+    map_info->load_bias = 0;
 
     elf = new ElfFake(new MemoryFake);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
@@ -103,40 +110,76 @@ class UnwinderTest : public ::testing::Test {
 
     elf = new ElfFake(new MemoryFake);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    AddMapInfo(0xa7000, 0xa8000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "/fake/fake_offset.oat",
-               elf);
-    const auto& info2 = *--maps_->end();
-    info2->elf_offset = 0x8000;
+    map_info = AddMapInfo(0xa7000, 0xa8000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
+                          "/fake/fake_offset.oat", elf);
+    map_info->elf_offset = 0x8000;
 
     elf = new ElfFake(new MemoryFake);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    AddMapInfo(0xc0000, 0xc1000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "/fake/unreadable.so", elf);
-    const auto& info3 = *--maps_->end();
-    info3->memory_backed_elf = true;
+    map_info = AddMapInfo(0xc0000, 0xc1000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
+                          "/fake/unreadable.so", elf);
+    map_info->memory_backed_elf = true;
 
     elf = new ElfFake(new MemoryFake);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    AddMapInfo(0xc1000, 0xc2000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "[vdso]", elf);
-    const auto& info4 = *--maps_->end();
-    info4->memory_backed_elf = true;
+    map_info = AddMapInfo(0xc1000, 0xc2000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "[vdso]", elf);
+    map_info->memory_backed_elf = true;
 
     elf = new ElfFake(new MemoryFake);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    AddMapInfo(0xc2000, 0xc3000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "", elf);
-    const auto& info5 = *--maps_->end();
-    info5->memory_backed_elf = true;
+    map_info = AddMapInfo(0xc2000, 0xc3000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "", elf);
+    map_info->memory_backed_elf = true;
 
     elf = new ElfFake(new MemoryFake);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    AddMapInfo(0xc3000, 0xc4000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "/memfd:/jit-cache", elf);
-    const auto& info6 = *--maps_->end();
-    info6->memory_backed_elf = true;
+    map_info = AddMapInfo(0xc3000, 0xc4000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
+                          "/memfd:/jit-cache", elf);
+    map_info->memory_backed_elf = true;
 
-    AddMapInfo(0xd0000, 0xd1000, 0x1000, PROT_READ | PROT_WRITE | PROT_EXEC, "/fake/fake.apk");
-    const auto& info7 = *--maps_->end();
-    info7->load_bias = 0;
+    map_info =
+        AddMapInfo(0xd0000, 0xd1000, 0x1000, PROT_READ | PROT_WRITE | PROT_EXEC, "/fake/fake.apk");
+    map_info->load_bias = 0;
 
-    process_memory_.reset(new MemoryFake);
+    elf = new ElfFake(new MemoryFake);
+    interface = new ElfInterfaceFake(nullptr);
+    elf->FakeSetInterface(interface);
+    interface->FakeSetGlobalVariable("__dex_debug_descriptor", 0x1800);
+    interface->FakeSetGlobalVariable("__jit_debug_descriptor", 0x1900);
+    interface->FakeSetDataOffset(0x1000);
+    interface->FakeSetDataVaddrStart(0x1000);
+    interface->FakeSetDataVaddrEnd(0x8000);
+    AddMapInfo(0xf0000, 0xf1000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "/fake/global.so", elf);
+    AddMapInfo(0xf1000, 0xf9000, 0x1000, PROT_READ | PROT_WRITE, "/fake/global.so");
+    // dex debug data
+    memory_->SetData32(0xf180c, 0xf3000);
+    memory_->SetData32(0xf3000, 0xf4000);
+    memory_->SetData32(0xf3004, 0xf4000);
+    memory_->SetData32(0xf3008, 0xf5000);
+    // jit debug data
+    memory_->SetData32(0xf1900, 1);
+    memory_->SetData32(0xf1904, 0);
+    memory_->SetData32(0xf1908, 0xf6000);
+    memory_->SetData32(0xf190c, 0xf6000);
+    memory_->SetData32(0xf6000, 0);
+    memory_->SetData32(0xf6004, 0);
+    memory_->SetData32(0xf6008, 0xf7000);
+    memory_->SetData32(0xf600c, 0);
+    memory_->SetData64(0xf6010, 0x1000);
+
+    elf = new ElfFake(new MemoryFake);
+    elf->FakeSetValid(false);
+    elf->FakeSetLoadBias(0x300);
+    map_info = AddMapInfo(0x100000, 0x101000, 0x1000, PROT_READ | PROT_WRITE | PROT_EXEC,
+                          "/fake/jit.so", elf);
+    map_info->elf_start_offset = 0x100;
+    map_info->offset = 0x200;
+
+#if 0
+    elf = new ElfFake(new MemoryFake);
+    interface = new ElfInterfaceFake(nullptr);
+    interface->FakePushFunctionData(FunctionData("Fake0", 10));
+    AddMapInfo(0x110000, 0x111000, 0x1000, PROT_READ | PROT_WRITE | PROT_EXEC, "/fake/elf.so", elf);
+#endif
   }
 
   void SetUp() override {
@@ -147,11 +190,13 @@ class UnwinderTest : public ::testing::Test {
 
   static std::unique_ptr<Maps> maps_;
   static RegsFake regs_;
+  static MemoryFake* memory_;
   static std::shared_ptr<Memory> process_memory_;
 };
 
 std::unique_ptr<Maps> UnwinderTest::maps_;
 RegsFake UnwinderTest::regs_(5);
+MemoryFake* UnwinderTest::memory_;
 std::shared_ptr<Memory> UnwinderTest::process_memory_(nullptr);
 
 TEST_F(UnwinderTest, multiple_frames) {
@@ -168,6 +213,7 @@ TEST_F(UnwinderTest, multiple_frames) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(3U, unwinder.NumFrames());
@@ -233,6 +279,7 @@ TEST_F(UnwinderTest, multiple_frames_dont_resolve_names) {
   unwinder.SetResolveNames(false);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(3U, unwinder.NumFrames());
@@ -293,6 +340,7 @@ TEST_F(UnwinderTest, non_zero_load_bias) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(1U, unwinder.NumFrames());
@@ -323,6 +371,7 @@ TEST_F(UnwinderTest, non_zero_elf_offset) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(1U, unwinder.NumFrames());
@@ -353,6 +402,7 @@ TEST_F(UnwinderTest, non_zero_map_offset) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(1U, unwinder.NumFrames());
@@ -384,6 +434,7 @@ TEST_F(UnwinderTest, disable_embedded_soname) {
   unwinder.SetEmbeddedSoname(false);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(1U, unwinder.NumFrames());
@@ -421,6 +472,7 @@ TEST_F(UnwinderTest, no_frames_after_finished) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(1U, unwinder.NumFrames());
@@ -454,6 +506,7 @@ TEST_F(UnwinderTest, max_frames) {
   Unwinder unwinder(20, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_MAX_FRAMES_EXCEEDED, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(20U, unwinder.NumFrames());
@@ -497,6 +550,7 @@ TEST_F(UnwinderTest, verify_frames_skipped) {
   std::vector<std::string> skip_libs{"libunwind.so", "libanother.so"};
   unwinder.Unwind(&skip_libs);
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(3U, unwinder.NumFrames());
@@ -559,6 +613,7 @@ TEST_F(UnwinderTest, sp_not_in_map) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(2U, unwinder.NumFrames());
@@ -607,6 +662,7 @@ TEST_F(UnwinderTest, pc_in_device_stops_unwind) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(1U, unwinder.NumFrames());
@@ -627,6 +683,7 @@ TEST_F(UnwinderTest, sp_in_device_stops_unwind) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(1U, unwinder.NumFrames());
@@ -642,6 +699,7 @@ TEST_F(UnwinderTest, pc_without_map) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_INVALID_MAP, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(1U, unwinder.NumFrames());
@@ -679,6 +737,7 @@ TEST_F(UnwinderTest, speculative_frame) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(3U, unwinder.NumFrames());
@@ -745,6 +804,7 @@ TEST_F(UnwinderTest, speculative_frame_removed) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_INVALID_MAP, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(2U, unwinder.NumFrames());
@@ -795,6 +855,7 @@ TEST_F(UnwinderTest, speculative_frame_not_removed_pc_bad) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(2U, unwinder.NumFrames());
@@ -843,6 +904,7 @@ TEST_F(UnwinderTest, speculative_frame_check_with_no_frames) {
   std::vector<std::string> skip_names{"libanother.so"};
   unwinder.Unwind(&skip_names);
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(0U, unwinder.NumFrames());
@@ -866,6 +928,7 @@ TEST_F(UnwinderTest, map_ignore_suffixes) {
   std::vector<std::string> suffixes{"oat"};
   unwinder.Unwind(nullptr, &suffixes);
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(2U, unwinder.NumFrames());
@@ -925,6 +988,7 @@ TEST_F(UnwinderTest, sp_pc_do_not_change) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_REPEATED_FRAME, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(3U, unwinder.NumFrames());
@@ -984,6 +1048,7 @@ TEST_F(UnwinderTest, dex_pc_in_map) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(2U, unwinder.NumFrames());
@@ -1028,6 +1093,7 @@ TEST_F(UnwinderTest, dex_pc_in_map_non_zero_offset) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(2U, unwinder.NumFrames());
@@ -1072,6 +1138,54 @@ TEST_F(UnwinderTest, dex_pc_not_in_map) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_DEX_PC_NOT_IN_MAP, unwinder.warnings());
+  EXPECT_FALSE(unwinder.elf_from_memory_not_file());
+
+  ASSERT_EQ(2U, unwinder.NumFrames());
+
+  auto* frame = &unwinder.frames()[0];
+  EXPECT_EQ(0U, frame->num);
+  EXPECT_EQ(0x50000U, frame->rel_pc);
+  EXPECT_EQ(0x50000U, frame->pc);
+  EXPECT_EQ(0x10000U, frame->sp);
+  EXPECT_EQ("", frame->function_name);
+  EXPECT_EQ(0U, frame->function_offset);
+  EXPECT_EQ("", frame->map_name);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
+  EXPECT_EQ(0U, frame->map_start);
+  EXPECT_EQ(0U, frame->map_end);
+  EXPECT_EQ(0U, frame->map_load_bias);
+  EXPECT_EQ(0, frame->map_flags);
+
+  frame = &unwinder.frames()[1];
+  EXPECT_EQ(1U, frame->num);
+  EXPECT_EQ(0U, frame->rel_pc);
+  EXPECT_EQ(0x1000U, frame->pc);
+  EXPECT_EQ(0x10000U, frame->sp);
+  EXPECT_EQ("Frame0", frame->function_name);
+  EXPECT_EQ(0U, frame->function_offset);
+  EXPECT_EQ("/system/fake/libc.so", frame->map_name);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
+  EXPECT_EQ(0x1000U, frame->map_start);
+  EXPECT_EQ(0x8000U, frame->map_end);
+  EXPECT_EQ(0U, frame->map_load_bias);
+  EXPECT_EQ(PROT_READ | PROT_WRITE, frame->map_flags);
+}
+
+TEST_F(UnwinderTest, dex_pc_not_in_map_valid_dex_files) {
+  ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame0", 0));
+  regs_.set_pc(0x1000);
+  regs_.set_sp(0x10000);
+  regs_.FakeSetDexPc(0x50000);
+
+  DexFiles dex_files(process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
+  unwinder.SetDexFiles(&dex_files, ARCH_ARM);
+  unwinder.Unwind();
+  EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_DEX_PC_NOT_IN_MAP, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(2U, unwinder.NumFrames());
@@ -1119,6 +1233,7 @@ TEST_F(UnwinderTest, dex_pc_multiple_frames) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(3U, unwinder.NumFrames());
@@ -1178,6 +1293,7 @@ TEST_F(UnwinderTest, dex_pc_max_frames) {
   Unwinder unwinder(1, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_MAX_FRAMES_EXCEEDED, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(1U, unwinder.NumFrames());
@@ -1208,6 +1324,7 @@ TEST_F(UnwinderTest, elf_from_memory_not_file) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_TRUE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(1U, unwinder.NumFrames());
@@ -1238,6 +1355,7 @@ TEST_F(UnwinderTest, elf_from_memory_but_no_valid_file_with_bracket) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(1U, unwinder.NumFrames());
@@ -1268,6 +1386,7 @@ TEST_F(UnwinderTest, elf_from_memory_but_empty_filename) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(1U, unwinder.NumFrames());
@@ -1298,6 +1417,7 @@ TEST_F(UnwinderTest, elf_from_memory_but_from_memfd) {
   Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
+  EXPECT_EQ(WARNING_NONE, unwinder.warnings());
   EXPECT_FALSE(unwinder.elf_from_memory_not_file());
 
   ASSERT_EQ(1U, unwinder.NumFrames());
@@ -1474,4 +1594,161 @@ TEST_F(UnwinderTest, format_frame_by_arch) {
   }
 }
 
+TEST_F(UnwinderTest, build_frame_pc_only_errors) {
+  RegsFake regs(10);
+  regs.FakeSetArch(ARCH_ARM);
+  Unwinder unwinder(10, maps_.get(), &regs, process_memory_);
+
+  FrameData frame;
+
+  // Pc not in map
+  frame = unwinder.BuildFrameFromPcOnly(0x10);
+  EXPECT_EQ(0x10U, frame.pc);
+  EXPECT_EQ(0x10U, frame.rel_pc);
+
+  // No regs set
+  unwinder.SetRegs(nullptr);
+  frame = unwinder.BuildFrameFromPcOnly(0x100310);
+  EXPECT_EQ(0x100310U, frame.pc);
+  EXPECT_EQ(0x100310U, frame.rel_pc);
+  unwinder.SetRegs(&regs);
+
+  // Invalid elf
+  frame = unwinder.BuildFrameFromPcOnly(0x100310);
+  EXPECT_EQ(0x10030eU, frame.pc);
+  EXPECT_EQ(0x60eU, frame.rel_pc);
+  EXPECT_EQ("/fake/jit.so", frame.map_name);
+  EXPECT_EQ(0x100U, frame.map_elf_start_offset);
+  EXPECT_EQ(0x200U, frame.map_exact_offset);
+  EXPECT_EQ(0x100000U, frame.map_start);
+  EXPECT_EQ(0x101000U, frame.map_end);
+  EXPECT_EQ(PROT_READ | PROT_WRITE | PROT_EXEC, frame.map_flags);
+  EXPECT_EQ(0x300U, frame.map_load_bias);
+  EXPECT_EQ("", frame.function_name);
+  EXPECT_EQ(0U, frame.function_offset);
+}
+
+TEST_F(UnwinderTest, build_frame_pc_valid_elf) {
+  RegsFake regs(10);
+  regs.FakeSetArch(ARCH_ARM);
+  Unwinder unwinder(10, maps_.get(), &regs, process_memory_);
+
+  FrameData frame;
+
+  // Valid elf, no function data.
+  frame = unwinder.BuildFrameFromPcOnly(0x1010);
+  EXPECT_EQ(0x100cU, frame.pc);
+  EXPECT_EQ(0xcU, frame.rel_pc);
+  EXPECT_EQ("/system/fake/libc.so", frame.map_name);
+  EXPECT_EQ(0U, frame.map_elf_start_offset);
+  EXPECT_EQ(0U, frame.map_exact_offset);
+  EXPECT_EQ(0x1000U, frame.map_start);
+  EXPECT_EQ(0x8000U, frame.map_end);
+  EXPECT_EQ(PROT_READ | PROT_WRITE, frame.map_flags);
+  EXPECT_EQ(0U, frame.map_load_bias);
+  EXPECT_EQ("", frame.function_name);
+  EXPECT_EQ(0U, frame.function_offset);
+
+  // Valid elf, function data present, but do not resolve.
+  ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame0", 10));
+  unwinder.SetResolveNames(false);
+
+  frame = unwinder.BuildFrameFromPcOnly(0x1010);
+  EXPECT_EQ(0x100cU, frame.pc);
+  EXPECT_EQ(0xcU, frame.rel_pc);
+  EXPECT_EQ("/system/fake/libc.so", frame.map_name);
+  EXPECT_EQ(0U, frame.map_elf_start_offset);
+  EXPECT_EQ(0U, frame.map_exact_offset);
+  EXPECT_EQ(0x1000U, frame.map_start);
+  EXPECT_EQ(0x8000U, frame.map_end);
+  EXPECT_EQ(PROT_READ | PROT_WRITE, frame.map_flags);
+  EXPECT_EQ(0U, frame.map_load_bias);
+  EXPECT_EQ("", frame.function_name);
+  EXPECT_EQ(0U, frame.function_offset);
+
+  // Valid elf, function data present.
+  unwinder.SetResolveNames(true);
+
+  frame = unwinder.BuildFrameFromPcOnly(0x1010);
+  EXPECT_EQ(0x100cU, frame.pc);
+  EXPECT_EQ(0xcU, frame.rel_pc);
+  EXPECT_EQ("/system/fake/libc.so", frame.map_name);
+  EXPECT_EQ(0U, frame.map_elf_start_offset);
+  EXPECT_EQ(0U, frame.map_exact_offset);
+  EXPECT_EQ(0x1000U, frame.map_start);
+  EXPECT_EQ(0x8000U, frame.map_end);
+  EXPECT_EQ(PROT_READ | PROT_WRITE, frame.map_flags);
+  EXPECT_EQ(0U, frame.map_load_bias);
+  EXPECT_EQ("Frame0", frame.function_name);
+  EXPECT_EQ(10U, frame.function_offset);
+}
+
+TEST_F(UnwinderTest, build_frame_pc_in_jit) {
+  // Create the elf data for the jit debug information.
+  Elf32_Ehdr ehdr = {};
+  TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
+  ehdr.e_phoff = 0x50;
+  ehdr.e_phnum = 1;
+  ehdr.e_phentsize = sizeof(Elf32_Phdr);
+  ehdr.e_shoff = 0x100;
+  ehdr.e_shstrndx = 1;
+  ehdr.e_shentsize = sizeof(Elf32_Shdr);
+  ehdr.e_shnum = 3;
+  memory_->SetMemory(0xf7000, &ehdr, sizeof(ehdr));
+
+  Elf32_Phdr phdr = {};
+  phdr.p_flags = PF_X;
+  phdr.p_type = PT_LOAD;
+  phdr.p_offset = 0x100000;
+  phdr.p_vaddr = 0x100000;
+  phdr.p_memsz = 0x1000;
+  memory_->SetMemory(0xf7050, &phdr, sizeof(phdr));
+
+  Elf32_Shdr shdr = {};
+  shdr.sh_type = SHT_NULL;
+  memory_->SetMemory(0xf7100, &shdr, sizeof(shdr));
+
+  shdr.sh_type = SHT_SYMTAB;
+  shdr.sh_link = 2;
+  shdr.sh_addr = 0x300;
+  shdr.sh_offset = 0x300;
+  shdr.sh_entsize = sizeof(Elf32_Sym);
+  shdr.sh_size = shdr.sh_entsize;
+  memory_->SetMemory(0xf7100 + sizeof(shdr), &shdr, sizeof(shdr));
+
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_STRTAB;
+  shdr.sh_name = 0x500;
+  shdr.sh_offset = 0x400;
+  shdr.sh_size = 0x100;
+  memory_->SetMemory(0xf7100 + 2 * sizeof(shdr), &shdr, sizeof(shdr));
+
+  Elf32_Sym sym = {};
+  sym.st_shndx = 2;
+  sym.st_info = STT_FUNC;
+  sym.st_value = 0x100300;
+  sym.st_size = 0x100;
+  memory_->SetMemory(0xf7300, &sym, sizeof(sym));
+  memory_->SetMemory(0xf7400, "FakeJitFunction");
+
+  RegsFake regs(10);
+  regs.FakeSetArch(ARCH_ARM);
+  JitDebug jit_debug(process_memory_);
+  Unwinder unwinder(10, maps_.get(), &regs, process_memory_);
+  unwinder.SetJitDebug(&jit_debug, ARCH_ARM);
+
+  FrameData frame = unwinder.BuildFrameFromPcOnly(0x100310);
+  EXPECT_EQ(0x10030eU, frame.pc);
+  EXPECT_EQ(0x60eU, frame.rel_pc);
+  EXPECT_EQ("/fake/jit.so", frame.map_name);
+  EXPECT_EQ(0x100U, frame.map_elf_start_offset);
+  EXPECT_EQ(0x200U, frame.map_exact_offset);
+  EXPECT_EQ(0x100000U, frame.map_start);
+  EXPECT_EQ(0x101000U, frame.map_end);
+  EXPECT_EQ(PROT_READ | PROT_WRITE | PROT_EXEC, frame.map_flags);
+  EXPECT_EQ(0U, frame.map_load_bias);
+  EXPECT_EQ("FakeJitFunction", frame.function_name);
+  EXPECT_EQ(0xeU, frame.function_offset);
+}
+
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/fuzz/UnwinderComponentCreator.cpp b/libunwindstack/tests/fuzz/UnwinderComponentCreator.cpp
index 94f5a73cd..9c5374a5b 100644
--- a/libunwindstack/tests/fuzz/UnwinderComponentCreator.cpp
+++ b/libunwindstack/tests/fuzz/UnwinderComponentCreator.cpp
@@ -16,6 +16,11 @@
 
 #include "UnwinderComponentCreator.h"
 
+#include <map>
+#include <memory>
+#include <string>
+#include <vector>
+
 std::unique_ptr<Regs> GetRegisters(ArchEnum arch) {
   switch (arch) {
     case unwindstack::ARCH_ARM: {
@@ -109,13 +114,35 @@ ElfFake* PopulateElfFake(FuzzedDataProvider* data_provider) {
   return elf;
 }
 
+static constexpr size_t kPageSize = 4096;
+
+static constexpr uint64_t AlignToPage(uint64_t address) {
+  return (address + kPageSize - 1) & ~(kPageSize - 1);
+}
+
 std::unique_ptr<Maps> GetMaps(FuzzedDataProvider* data_provider) {
   std::unique_ptr<Maps> maps = std::make_unique<Maps>();
+  std::map<uint64_t, uint64_t> map_ends;
   uint8_t entry_count = data_provider->ConsumeIntegralInRange<uint8_t>(0, kMaxMapEntryCount);
   for (uint8_t i = 0; i < entry_count; i++) {
-    uint64_t start = data_provider->ConsumeIntegral<uint64_t>();
-    uint64_t end = data_provider->ConsumeIntegralInRange<uint64_t>(start, UINT64_MAX);
-    uint64_t offset = data_provider->ConsumeIntegral<uint64_t>();
+    uint64_t start = AlignToPage(data_provider->ConsumeIntegral<uint64_t>());
+    uint64_t end = AlignToPage(data_provider->ConsumeIntegralInRange<uint64_t>(start, UINT64_MAX));
+    if (start == end) {
+      // It's impossible to see start == end in the real world, so
+      // make sure the map contains at least one page of data.
+      if (__builtin_add_overflow(end, 0x1000, &end)) {
+        continue;
+      }
+    }
+    // Make sure not to add overlapping maps, that is not something that can
+    // happen in the real world.
+    auto entry = map_ends.upper_bound(start);
+    if (entry != map_ends.end() && end > entry->second) {
+      continue;
+    }
+    map_ends[end] = start;
+
+    uint64_t offset = AlignToPage(data_provider->ConsumeIntegral<uint64_t>());
     std::string map_info_name = data_provider->ConsumeRandomLengthString(kMaxMapInfoNameLen);
     uint8_t flags = PROT_READ | PROT_WRITE;