Small behavioral changes to the unwinder.
- Be a little more lenient when reading the cies/fdes. If next entry data
winds up incorrect, don't fail, simply stop processing the entries. This
only applies when reading all of the cies/fdes at once.
- Fail to init an eh_frame with no entries and fallback to assuming the
eh_frame has no header instead.
- Change the step to always try debug_frame first which has the most
accurate information.
- Add small unit tests and a couple of offline unit tests to verify
this behavior.
These changes are needed to support offline unwinding since it depends
on this new behavior.
Bug: 65682279
Test: Ran new unit tests.
Change-Id: I3529f1b0c8e14cd7409494e5de2f3c9e78d0855e
diff --git a/libunwindstack/Android.bp b/libunwindstack/Android.bp
index 9389b40..8dae956 100644
--- a/libunwindstack/Android.bp
+++ b/libunwindstack/Android.bp
@@ -170,6 +170,8 @@
data: [
"tests/files/elf32.xz",
"tests/files/elf64.xz",
+ "tests/files/offline/bad_eh_frame_hdr_arm64/*",
+ "tests/files/offline/debug_frame_first_x86/*",
"tests/files/offline/jit_debug_arm32/*",
"tests/files/offline/jit_debug_x86_32/*",
"tests/files/offline/gnu_debugdata_arm32/*",
diff --git a/libunwindstack/DwarfEhFrameWithHdr.cpp b/libunwindstack/DwarfEhFrameWithHdr.cpp
index 0337dba..e0f1eed 100644
--- a/libunwindstack/DwarfEhFrameWithHdr.cpp
+++ b/libunwindstack/DwarfEhFrameWithHdr.cpp
@@ -64,6 +64,11 @@
return false;
}
+ if (fde_count_ == 0) {
+ last_error_ = DWARF_ERROR_NO_FDES;
+ return false;
+ }
+
entries_offset_ = memory_.cur_offset();
entries_end_ = offset + size;
entries_data_offset_ = offset;
diff --git a/libunwindstack/DwarfError.h b/libunwindstack/DwarfError.h
index 54199b8..d3cdd4d 100644
--- a/libunwindstack/DwarfError.h
+++ b/libunwindstack/DwarfError.h
@@ -31,6 +31,7 @@
DWARF_ERROR_TOO_MANY_ITERATIONS,
DWARF_ERROR_CFA_NOT_DEFINED,
DWARF_ERROR_UNSUPPORTED_VERSION,
+ DWARF_ERROR_NO_FDES,
};
} // namespace unwindstack
diff --git a/libunwindstack/DwarfSection.cpp b/libunwindstack/DwarfSection.cpp
index 91d855b..04a1fae 100644
--- a/libunwindstack/DwarfSection.cpp
+++ b/libunwindstack/DwarfSection.cpp
@@ -835,9 +835,8 @@
}
if (next_entry_offset < memory_.cur_offset()) {
- // This indicates some kind of corruption, or malformed section data.
- last_error_ = DWARF_ERROR_ILLEGAL_VALUE;
- return false;
+ // Simply consider the processing done in this case.
+ break;
}
memory_.set_cur_offset(next_entry_offset);
}
diff --git a/libunwindstack/ElfInterface.cpp b/libunwindstack/ElfInterface.cpp
index 0e3ab2c..17cc16a 100644
--- a/libunwindstack/ElfInterface.cpp
+++ b/libunwindstack/ElfInterface.cpp
@@ -126,22 +126,26 @@
if (eh_frame_hdr_offset_ != 0) {
eh_frame_.reset(new DwarfEhFrameWithHdr<AddressType>(memory_));
if (!eh_frame_->Init(eh_frame_hdr_offset_, eh_frame_hdr_size_)) {
- // Even if the eh_frame_offset_ is non-zero, do not bother
- // trying to read that since something has gone wrong.
eh_frame_.reset(nullptr);
- eh_frame_hdr_offset_ = 0;
- eh_frame_hdr_size_ = static_cast<uint64_t>(-1);
}
- } else if (eh_frame_offset_ != 0) {
- // If there is a eh_frame section without a eh_frame_hdr section.
+ }
+
+ if (eh_frame_.get() == nullptr && eh_frame_offset_ != 0) {
+ // If there is an eh_frame section without an eh_frame_hdr section,
+ // or using the frame hdr object failed to init.
eh_frame_.reset(new DwarfEhFrame<AddressType>(memory_));
if (!eh_frame_->Init(eh_frame_offset_, eh_frame_size_)) {
eh_frame_.reset(nullptr);
- eh_frame_offset_ = 0;
- eh_frame_size_ = static_cast<uint64_t>(-1);
}
}
+ if (eh_frame_.get() == nullptr) {
+ eh_frame_hdr_offset_ = 0;
+ eh_frame_hdr_size_ = static_cast<uint64_t>(-1);
+ eh_frame_offset_ = 0;
+ eh_frame_size_ = static_cast<uint64_t>(-1);
+ }
+
if (debug_frame_offset_ != 0) {
debug_frame_.reset(new DwarfDebugFrame<AddressType>(memory_));
if (!debug_frame_->Init(debug_frame_offset_, debug_frame_size_)) {
@@ -436,15 +440,16 @@
}
uint64_t adjusted_pc = pc - load_bias;
- // Try the eh_frame first.
- DwarfSection* eh_frame = eh_frame_.get();
- if (eh_frame != nullptr && eh_frame->Step(adjusted_pc, regs, process_memory, finished)) {
+ // Try the debug_frame first since it contains the most specific unwind
+ // information.
+ DwarfSection* debug_frame = debug_frame_.get();
+ if (debug_frame != nullptr && debug_frame->Step(adjusted_pc, regs, process_memory, finished)) {
return true;
}
- // Try the debug_frame next.
- DwarfSection* debug_frame = debug_frame_.get();
- if (debug_frame != nullptr && debug_frame->Step(adjusted_pc, regs, process_memory, finished)) {
+ // Try the eh_frame next.
+ DwarfSection* eh_frame = eh_frame_.get();
+ if (eh_frame != nullptr && eh_frame->Step(adjusted_pc, regs, process_memory, finished)) {
return true;
}
diff --git a/libunwindstack/tests/DwarfDebugFrameTest.cpp b/libunwindstack/tests/DwarfDebugFrameTest.cpp
index 07204bc..243198e 100644
--- a/libunwindstack/tests/DwarfDebugFrameTest.cpp
+++ b/libunwindstack/tests/DwarfDebugFrameTest.cpp
@@ -145,6 +145,45 @@
ASSERT_EQ(DWARF_ERROR_ILLEGAL_VALUE, this->debug_frame_->last_error());
}
+TYPED_TEST_P(DwarfDebugFrameTest, Init32_do_not_fail_on_bad_next_entry) {
+ // CIE 32 information.
+ this->memory_.SetData32(0x5000, 0xfc);
+ this->memory_.SetData32(0x5004, 0xffffffff);
+ this->memory_.SetData8(0x5008, 1);
+ this->memory_.SetData8(0x5009, '\0');
+
+ // FDE 32 information.
+ this->memory_.SetData32(0x5100, 0xfc);
+ this->memory_.SetData32(0x5104, 0);
+ this->memory_.SetData32(0x5108, 0x1500);
+ this->memory_.SetData32(0x510c, 0x200);
+
+ this->memory_.SetData32(0x5200, 0xfc);
+ this->memory_.SetData32(0x5204, 0);
+ this->memory_.SetData32(0x5208, 0x2500);
+ this->memory_.SetData32(0x520c, 0x300);
+
+ // CIE 32 information.
+ this->memory_.SetData32(0x5300, 0);
+ this->memory_.SetData32(0x5304, 0xffffffff);
+ this->memory_.SetData8(0x5308, 1);
+ this->memory_.SetData8(0x5309, '\0');
+
+ // FDE 32 information.
+ this->memory_.SetData32(0x5400, 0xfc);
+ this->memory_.SetData32(0x5404, 0x300);
+ this->memory_.SetData32(0x5408, 0x3500);
+ this->memory_.SetData32(0x540c, 0x400);
+
+ this->memory_.SetData32(0x5500, 0xfc);
+ this->memory_.SetData32(0x5504, 0x300);
+ this->memory_.SetData32(0x5508, 0x4500);
+ this->memory_.SetData32(0x550c, 0x500);
+
+ ASSERT_TRUE(this->debug_frame_->Init(0x5000, 0x600));
+ ASSERT_EQ(2U, this->debug_frame_->TestGetFdeCount());
+}
+
TYPED_TEST_P(DwarfDebugFrameTest, Init64) {
// CIE 64 information.
this->memory_.SetData32(0x5000, 0xffffffff);
@@ -231,6 +270,51 @@
ASSERT_EQ(DWARF_ERROR_ILLEGAL_VALUE, this->debug_frame_->last_error());
}
+TYPED_TEST_P(DwarfDebugFrameTest, Init64_do_not_fail_on_bad_next_entry) {
+ // CIE 64 information.
+ this->memory_.SetData32(0x5000, 0xffffffff);
+ this->memory_.SetData64(0x5004, 0xf4);
+ this->memory_.SetData64(0x500c, 0xffffffffffffffffULL);
+ this->memory_.SetData8(0x5014, 1);
+ this->memory_.SetData8(0x5015, '\0');
+
+ // FDE 64 information.
+ this->memory_.SetData32(0x5100, 0xffffffff);
+ this->memory_.SetData64(0x5104, 0xf4);
+ this->memory_.SetData64(0x510c, 0);
+ this->memory_.SetData64(0x5114, 0x1500);
+ this->memory_.SetData64(0x511c, 0x200);
+
+ this->memory_.SetData32(0x5200, 0xffffffff);
+ this->memory_.SetData64(0x5204, 0xf4);
+ this->memory_.SetData64(0x520c, 0);
+ this->memory_.SetData64(0x5214, 0x2500);
+ this->memory_.SetData64(0x521c, 0x300);
+
+ // CIE 64 information.
+ this->memory_.SetData32(0x5300, 0xffffffff);
+ this->memory_.SetData64(0x5304, 0);
+ this->memory_.SetData64(0x530c, 0xffffffffffffffffULL);
+ this->memory_.SetData8(0x5314, 1);
+ this->memory_.SetData8(0x5315, '\0');
+
+ // FDE 64 information.
+ this->memory_.SetData32(0x5400, 0xffffffff);
+ this->memory_.SetData64(0x5404, 0xf4);
+ this->memory_.SetData64(0x540c, 0x300);
+ this->memory_.SetData64(0x5414, 0x3500);
+ this->memory_.SetData64(0x541c, 0x400);
+
+ this->memory_.SetData32(0x5500, 0xffffffff);
+ this->memory_.SetData64(0x5504, 0xf4);
+ this->memory_.SetData64(0x550c, 0x300);
+ this->memory_.SetData64(0x5514, 0x4500);
+ this->memory_.SetData64(0x551c, 0x500);
+
+ ASSERT_TRUE(this->debug_frame_->Init(0x5000, 0x600));
+ ASSERT_EQ(2U, this->debug_frame_->TestGetFdeCount());
+}
+
TYPED_TEST_P(DwarfDebugFrameTest, Init_version1) {
// CIE 32 information.
this->memory_.SetData32(0x5000, 0xfc);
@@ -450,9 +534,11 @@
EXPECT_EQ(0x20U, fde->cie->return_address_register);
}
-REGISTER_TYPED_TEST_CASE_P(DwarfDebugFrameTest, Init32, Init32_fde_not_following_cie, Init64,
- Init64_fde_not_following_cie, Init_version1, Init_version4,
- GetFdeOffsetFromPc, GetCieFde32, GetCieFde64);
+REGISTER_TYPED_TEST_CASE_P(DwarfDebugFrameTest, Init32, Init32_fde_not_following_cie,
+ Init32_do_not_fail_on_bad_next_entry, Init64,
+ Init64_do_not_fail_on_bad_next_entry, Init64_fde_not_following_cie,
+ Init_version1, Init_version4, GetFdeOffsetFromPc, GetCieFde32,
+ GetCieFde64);
typedef ::testing::Types<uint32_t, uint64_t> DwarfDebugFrameTestTypes;
INSTANTIATE_TYPED_TEST_CASE_P(, DwarfDebugFrameTest, DwarfDebugFrameTestTypes);
diff --git a/libunwindstack/tests/DwarfEhFrameWithHdrTest.cpp b/libunwindstack/tests/DwarfEhFrameWithHdrTest.cpp
index 64b325b..ef2fb32 100644
--- a/libunwindstack/tests/DwarfEhFrameWithHdrTest.cpp
+++ b/libunwindstack/tests/DwarfEhFrameWithHdrTest.cpp
@@ -94,7 +94,13 @@
EXPECT_EQ(0x1000U, this->eh_frame_->TestGetEntriesDataOffset());
EXPECT_EQ(0x100aU, this->eh_frame_->TestGetCurEntriesOffset());
+ // Verify a zero fde count fails to init.
+ this->memory_.SetData32(0x1006, 0);
+ ASSERT_FALSE(this->eh_frame_->Init(0x1000, 0x100));
+ ASSERT_EQ(DWARF_ERROR_NO_FDES, this->eh_frame_->last_error());
+
// Verify an unexpected version will cause a fail.
+ this->memory_.SetData32(0x1006, 126);
this->memory_.SetData8(0x1000, 0);
ASSERT_FALSE(this->eh_frame_->Init(0x1000, 0x100));
ASSERT_EQ(DWARF_ERROR_UNSUPPORTED_VERSION, this->eh_frame_->last_error());
diff --git a/libunwindstack/tests/UnwindOfflineTest.cpp b/libunwindstack/tests/UnwindOfflineTest.cpp
index 582ac18..09376ab 100644
--- a/libunwindstack/tests/UnwindOfflineTest.cpp
+++ b/libunwindstack/tests/UnwindOfflineTest.cpp
@@ -625,4 +625,127 @@
frame_info);
}
+// The eh_frame_hdr data is present but set to zero fdes. This should
+// fallback to iterating over the cies/fdes and ignore the eh_frame_hdr.
+// No .gnu_debugdata section in the elf file, so no symbols.
+TEST(UnwindOfflineTest, bad_eh_frame_hdr_arm64) {
+ std::string dir(TestGetFileDirectory() + "offline/bad_eh_frame_hdr_arm64/");
+
+ MemoryOffline* memory = new MemoryOffline;
+ ASSERT_TRUE(memory->Init((dir + "stack.data").c_str(), 0));
+
+ FILE* fp = fopen((dir + "regs.txt").c_str(), "r");
+ ASSERT_TRUE(fp != nullptr);
+ RegsArm64 regs;
+ uint64_t reg_value;
+ ASSERT_EQ(1, fscanf(fp, "pc: %" SCNx64 "\n", ®_value));
+ regs[ARM64_REG_PC] = reg_value;
+ ASSERT_EQ(1, fscanf(fp, "sp: %" SCNx64 "\n", ®_value));
+ regs[ARM64_REG_SP] = reg_value;
+ ASSERT_EQ(1, fscanf(fp, "lr: %" SCNx64 "\n", ®_value));
+ regs[ARM64_REG_LR] = reg_value;
+ ASSERT_EQ(1, fscanf(fp, "x29: %" SCNx64 "\n", ®_value));
+ regs[ARM64_REG_R29] = reg_value;
+ regs.SetFromRaw();
+ fclose(fp);
+
+ fp = fopen((dir + "maps.txt").c_str(), "r");
+ ASSERT_TRUE(fp != nullptr);
+ // The file is guaranteed to be less than 4096 bytes.
+ std::vector<char> buffer(4096);
+ ASSERT_NE(0U, fread(buffer.data(), 1, buffer.size(), fp));
+ fclose(fp);
+
+ BufferMaps maps(buffer.data());
+ ASSERT_TRUE(maps.Parse());
+
+ ASSERT_EQ(ARCH_ARM64, regs.Arch());
+
+ std::shared_ptr<Memory> process_memory(memory);
+
+ char* cwd = getcwd(nullptr, 0);
+ ASSERT_EQ(0, chdir(dir.c_str()));
+ Unwinder unwinder(128, &maps, ®s, process_memory);
+ unwinder.Unwind();
+ ASSERT_EQ(0, chdir(cwd));
+ free(cwd);
+
+ std::string frame_info(DumpFrames(unwinder));
+ ASSERT_EQ(5U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
+ EXPECT_EQ(
+ " #00 pc 0000000000000550 waiter64\n"
+ " #01 pc 0000000000000568 waiter64\n"
+ " #02 pc 000000000000057c waiter64\n"
+ " #03 pc 0000000000000590 waiter64\n"
+ " #04 pc 00000000000a8e98 libc.so (__libc_init+88)\n",
+ frame_info);
+}
+
+// The elf has bad eh_frame unwind information for the pcs. If eh_frame
+// is used first, the unwind will not match the expected output.
+TEST(UnwindOfflineTest, debug_frame_first_x86) {
+ std::string dir(TestGetFileDirectory() + "offline/debug_frame_first_x86/");
+
+ MemoryOffline* memory = new MemoryOffline;
+ ASSERT_TRUE(memory->Init((dir + "stack.data").c_str(), 0));
+
+ FILE* fp = fopen((dir + "regs.txt").c_str(), "r");
+ ASSERT_TRUE(fp != nullptr);
+ RegsX86 regs;
+ uint64_t reg_value;
+ ASSERT_EQ(1, fscanf(fp, "eax: %" SCNx64 "\n", ®_value));
+ regs[X86_REG_EAX] = reg_value;
+ ASSERT_EQ(1, fscanf(fp, "ebx: %" SCNx64 "\n", ®_value));
+ regs[X86_REG_EBX] = reg_value;
+ ASSERT_EQ(1, fscanf(fp, "ecx: %" SCNx64 "\n", ®_value));
+ regs[X86_REG_ECX] = reg_value;
+ ASSERT_EQ(1, fscanf(fp, "edx: %" SCNx64 "\n", ®_value));
+ regs[X86_REG_EDX] = reg_value;
+ ASSERT_EQ(1, fscanf(fp, "ebp: %" SCNx64 "\n", ®_value));
+ regs[X86_REG_EBP] = reg_value;
+ ASSERT_EQ(1, fscanf(fp, "edi: %" SCNx64 "\n", ®_value));
+ regs[X86_REG_EDI] = reg_value;
+ ASSERT_EQ(1, fscanf(fp, "esi: %" SCNx64 "\n", ®_value));
+ regs[X86_REG_ESI] = reg_value;
+ ASSERT_EQ(1, fscanf(fp, "esp: %" SCNx64 "\n", ®_value));
+ regs[X86_REG_ESP] = reg_value;
+ ASSERT_EQ(1, fscanf(fp, "eip: %" SCNx64 "\n", ®_value));
+ regs[X86_REG_EIP] = reg_value;
+ regs.SetFromRaw();
+ fclose(fp);
+
+ fp = fopen((dir + "maps.txt").c_str(), "r");
+ ASSERT_TRUE(fp != nullptr);
+ // The file is guaranteed to be less than 4096 bytes.
+ std::vector<char> buffer(4096);
+ ASSERT_NE(0U, fread(buffer.data(), 1, buffer.size(), fp));
+ fclose(fp);
+
+ BufferMaps maps(buffer.data());
+ ASSERT_TRUE(maps.Parse());
+
+ ASSERT_EQ(ARCH_X86, regs.Arch());
+
+ std::shared_ptr<Memory> process_memory(memory);
+
+ char* cwd = getcwd(nullptr, 0);
+ ASSERT_EQ(0, chdir(dir.c_str()));
+ JitDebug jit_debug(process_memory);
+ Unwinder unwinder(128, &maps, ®s, process_memory);
+ unwinder.SetJitDebug(&jit_debug, regs.Arch());
+ unwinder.Unwind();
+ ASSERT_EQ(0, chdir(cwd));
+ free(cwd);
+
+ std::string frame_info(DumpFrames(unwinder));
+ ASSERT_EQ(5U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
+ EXPECT_EQ(
+ " #00 pc 00000685 waiter (call_level3+53)\n"
+ " #01 pc 000006b7 waiter (call_level2+23)\n"
+ " #02 pc 000006d7 waiter (call_level1+23)\n"
+ " #03 pc 000006f7 waiter (main+23)\n"
+ " #04 pc 00018275 libc.so\n",
+ frame_info);
+}
+
} // namespace unwindstack
diff --git a/libunwindstack/tests/files/offline/bad_eh_frame_hdr_arm64/libc.so b/libunwindstack/tests/files/offline/bad_eh_frame_hdr_arm64/libc.so
new file mode 100644
index 0000000..78449bf
--- /dev/null
+++ b/libunwindstack/tests/files/offline/bad_eh_frame_hdr_arm64/libc.so
Binary files differ
diff --git a/libunwindstack/tests/files/offline/bad_eh_frame_hdr_arm64/maps.txt b/libunwindstack/tests/files/offline/bad_eh_frame_hdr_arm64/maps.txt
new file mode 100644
index 0000000..7cada15
--- /dev/null
+++ b/libunwindstack/tests/files/offline/bad_eh_frame_hdr_arm64/maps.txt
@@ -0,0 +1,2 @@
+60a9fdf000-60a9fe0000 r-xp 0 00:00 0 waiter64
+7542cc0000-7542d8e000 r-xp 0 00:00 0 libc.so
diff --git a/libunwindstack/tests/files/offline/bad_eh_frame_hdr_arm64/regs.txt b/libunwindstack/tests/files/offline/bad_eh_frame_hdr_arm64/regs.txt
new file mode 100644
index 0000000..c24adbe
--- /dev/null
+++ b/libunwindstack/tests/files/offline/bad_eh_frame_hdr_arm64/regs.txt
@@ -0,0 +1,4 @@
+pc: 60a9fdf550
+sp: 7fdd141990
+lr: 60a9fdf56c
+x29: 7fdd1419a0
diff --git a/libunwindstack/tests/files/offline/bad_eh_frame_hdr_arm64/stack.data b/libunwindstack/tests/files/offline/bad_eh_frame_hdr_arm64/stack.data
new file mode 100644
index 0000000..b56d420
--- /dev/null
+++ b/libunwindstack/tests/files/offline/bad_eh_frame_hdr_arm64/stack.data
Binary files differ
diff --git a/libunwindstack/tests/files/offline/bad_eh_frame_hdr_arm64/waiter64 b/libunwindstack/tests/files/offline/bad_eh_frame_hdr_arm64/waiter64
new file mode 100644
index 0000000..81bda1d
--- /dev/null
+++ b/libunwindstack/tests/files/offline/bad_eh_frame_hdr_arm64/waiter64
Binary files differ
diff --git a/libunwindstack/tests/files/offline/debug_frame_first_x86/libc.so b/libunwindstack/tests/files/offline/debug_frame_first_x86/libc.so
new file mode 100644
index 0000000..9c78790
--- /dev/null
+++ b/libunwindstack/tests/files/offline/debug_frame_first_x86/libc.so
Binary files differ
diff --git a/libunwindstack/tests/files/offline/debug_frame_first_x86/maps.txt b/libunwindstack/tests/files/offline/debug_frame_first_x86/maps.txt
new file mode 100644
index 0000000..74fc89f
--- /dev/null
+++ b/libunwindstack/tests/files/offline/debug_frame_first_x86/maps.txt
@@ -0,0 +1,2 @@
+56598000-56599000 r-xp 0 00:00 0 waiter
+f7432000-f75e3000 r-xp 0 00:00 0 libc.so
diff --git a/libunwindstack/tests/files/offline/debug_frame_first_x86/regs.txt b/libunwindstack/tests/files/offline/debug_frame_first_x86/regs.txt
new file mode 100644
index 0000000..48f4440
--- /dev/null
+++ b/libunwindstack/tests/files/offline/debug_frame_first_x86/regs.txt
@@ -0,0 +1,9 @@
+eax: 1d88ef8c
+ebx: 56599fe8
+ecx: 3
+edx: ffcf9ea4
+ebp: ffcf9e48
+edi: f75e5000
+esi: 1
+esp: ffcf9e38
+eip: 56598685
diff --git a/libunwindstack/tests/files/offline/debug_frame_first_x86/stack.data b/libunwindstack/tests/files/offline/debug_frame_first_x86/stack.data
new file mode 100644
index 0000000..0cf7d55
--- /dev/null
+++ b/libunwindstack/tests/files/offline/debug_frame_first_x86/stack.data
Binary files differ
diff --git a/libunwindstack/tests/files/offline/debug_frame_first_x86/waiter b/libunwindstack/tests/files/offline/debug_frame_first_x86/waiter
new file mode 100644
index 0000000..b1fc024
--- /dev/null
+++ b/libunwindstack/tests/files/offline/debug_frame_first_x86/waiter
Binary files differ
