Fix pc/function name for signal handler frame.
This refactors the step function slightly to split it up into
distinct pieces since the code needs to handle a signal handler
versus normal step slightly differently.
Add a new error for an invalid elf.
Modify libbacktrace code to handle new error code.
Bug: 130302288
Test: libbacktrace/libunwindstack unit tests.
Change-Id: I3fb9b00c02d2cf2cc5911541bba0346c6f39b8e6
diff --git a/libbacktrace/Backtrace.cpp b/libbacktrace/Backtrace.cpp
index 6bec63c..71980d7 100644
--- a/libbacktrace/Backtrace.cpp
+++ b/libbacktrace/Backtrace.cpp
@@ -170,5 +170,7 @@
return "Failed to unwind due to invalid unwind information";
case BACKTRACE_UNWIND_ERROR_REPEATED_FRAME:
return "Failed to unwind due to same sp/pc repeating";
+ case BACKTRACE_UNWIND_ERROR_INVALID_ELF:
+ return "Failed to unwind due to invalid elf";
}
}
diff --git a/libbacktrace/UnwindStack.cpp b/libbacktrace/UnwindStack.cpp
index f5f9b2a..36640cd 100644
--- a/libbacktrace/UnwindStack.cpp
+++ b/libbacktrace/UnwindStack.cpp
@@ -89,6 +89,10 @@
case unwindstack::ERROR_REPEATED_FRAME:
error->error_code = BACKTRACE_UNWIND_ERROR_REPEATED_FRAME;
break;
+
+ case unwindstack::ERROR_INVALID_ELF:
+ error->error_code = BACKTRACE_UNWIND_ERROR_INVALID_ELF;
+ break;
}
}
diff --git a/libbacktrace/include/backtrace/Backtrace.h b/libbacktrace/include/backtrace/Backtrace.h
index 10e790b..404e7e8 100644
--- a/libbacktrace/include/backtrace/Backtrace.h
+++ b/libbacktrace/include/backtrace/Backtrace.h
@@ -64,6 +64,8 @@
BACKTRACE_UNWIND_ERROR_UNWIND_INFO,
// Unwind information stopped due to sp/pc repeating.
BACKTRACE_UNWIND_ERROR_REPEATED_FRAME,
+ // Unwind information stopped due to invalid elf.
+ BACKTRACE_UNWIND_ERROR_INVALID_ELF,
};
struct BacktraceUnwindError {
diff --git a/libunwindstack/Elf.cpp b/libunwindstack/Elf.cpp
index 4b93abb..3454913 100644
--- a/libunwindstack/Elf.cpp
+++ b/libunwindstack/Elf.cpp
@@ -160,7 +160,7 @@
if (valid_) {
return interface_->LastErrorCode();
}
- return ERROR_NONE;
+ return ERROR_INVALID_ELF;
}
uint64_t Elf::GetLastErrorAddress() {
@@ -170,22 +170,23 @@
return 0;
}
+// The relative pc expectd by this function is relative to the start of the elf.
+bool Elf::StepIfSignalHandler(uint64_t rel_pc, Regs* regs, Memory* process_memory) {
+ if (!valid_) {
+ return false;
+ }
+ return regs->StepIfSignalHandler(rel_pc, this, process_memory);
+}
+
// The relative pc is always relative to the start of the map from which it comes.
-bool Elf::Step(uint64_t rel_pc, uint64_t adjusted_rel_pc, Regs* regs, Memory* process_memory,
- bool* finished) {
+bool Elf::Step(uint64_t rel_pc, Regs* regs, Memory* process_memory, bool* finished) {
if (!valid_) {
return false;
}
- // The relative pc expectd by StepIfSignalHandler is relative to the start of the elf.
- if (regs->StepIfSignalHandler(rel_pc, this, process_memory)) {
- *finished = false;
- return true;
- }
-
// Lock during the step which can update information in the object.
std::lock_guard<std::mutex> guard(lock_);
- return interface_->Step(adjusted_rel_pc, regs, process_memory, finished);
+ return interface_->Step(rel_pc, regs, process_memory, finished);
}
bool Elf::IsValidElf(Memory* memory) {
diff --git a/libunwindstack/LocalUnwinder.cpp b/libunwindstack/LocalUnwinder.cpp
index 5b2fadf..5d81200 100644
--- a/libunwindstack/LocalUnwinder.cpp
+++ b/libunwindstack/LocalUnwinder.cpp
@@ -111,6 +111,14 @@
pc_adjustment = 0;
}
step_pc -= pc_adjustment;
+
+ bool finished = false;
+ if (elf->StepIfSignalHandler(rel_pc, regs.get(), process_memory_.get())) {
+ step_pc = rel_pc;
+ } else if (!elf->Step(step_pc, regs.get(), process_memory_.get(), &finished)) {
+ finished = true;
+ }
+
// Skip any locations that are within this library.
if (num_frames != 0 || !ShouldSkipLibrary(map_info->name)) {
// Add frame information.
@@ -124,22 +132,12 @@
}
num_frames++;
}
- if (!elf->valid()) {
- break;
- }
- if (frame_info->size() == max_frames) {
- break;
- }
+ if (finished || frame_info->size() == max_frames ||
+ (cur_pc == regs->pc() && cur_sp == regs->sp())) {
+ break;
+ }
adjust_pc = true;
- bool finished;
- if (!elf->Step(rel_pc, step_pc, regs.get(), process_memory_.get(), &finished) || finished) {
- break;
- }
- // pc and sp are the same, terminate the unwind.
- if (cur_pc == regs->pc() && cur_sp == regs->sp()) {
- break;
- }
}
return num_frames != 0;
}
diff --git a/libunwindstack/Unwinder.cpp b/libunwindstack/Unwinder.cpp
index 3f2e1c1..f3d2b5e 100644
--- a/libunwindstack/Unwinder.cpp
+++ b/libunwindstack/Unwinder.cpp
@@ -89,8 +89,8 @@
#endif
}
-void Unwinder::FillInFrame(MapInfo* map_info, Elf* elf, uint64_t rel_pc, uint64_t func_pc,
- uint64_t pc_adjustment) {
+FrameData* Unwinder::FillInFrame(MapInfo* map_info, Elf* elf, uint64_t rel_pc,
+ uint64_t pc_adjustment) {
size_t frame_num = frames_.size();
frames_.resize(frame_num + 1);
FrameData* frame = &frames_.at(frame_num);
@@ -100,7 +100,8 @@
frame->pc = regs_->pc() - pc_adjustment;
if (map_info == nullptr) {
- return;
+ // Nothing else to update.
+ return nullptr;
}
if (resolve_names_) {
@@ -118,12 +119,7 @@
frame->map_end = map_info->end;
frame->map_flags = map_info->flags;
frame->map_load_bias = elf->GetLoadBias();
-
- if (!resolve_names_ ||
- !elf->GetFunctionName(func_pc, &frame->function_name, &frame->function_offset)) {
- frame->function_name = "";
- frame->function_offset = 0;
- }
+ return frame;
}
static bool ShouldStop(const std::vector<std::string>* map_suffixes_to_ignore,
@@ -194,6 +190,7 @@
}
}
+ FrameData* frame = nullptr;
if (map_info == nullptr || initial_map_names_to_skip == nullptr ||
std::find(initial_map_names_to_skip->begin(), initial_map_names_to_skip->end(),
basename(map_info->name.c_str())) == initial_map_names_to_skip->end()) {
@@ -210,23 +207,21 @@
}
}
- FillInFrame(map_info, elf, rel_pc, step_pc, pc_adjustment);
+ frame = FillInFrame(map_info, elf, rel_pc, pc_adjustment);
// Once a frame is added, stop skipping frames.
initial_map_names_to_skip = nullptr;
}
adjust_pc = true;
- bool stepped;
+ bool stepped = false;
bool in_device_map = false;
- if (map_info == nullptr) {
- stepped = false;
- } else {
+ bool finished = false;
+ if (map_info != nullptr) {
if (map_info->flags & MAPS_FLAGS_DEVICE_MAP) {
// Do not stop here, fall through in case we are
// in the speculative unwind path and need to remove
// some of the speculative frames.
- stepped = false;
in_device_map = true;
} else {
MapInfo* sp_info = maps_->Find(regs_->sp());
@@ -234,19 +229,37 @@
// Do not stop here, fall through in case we are
// in the speculative unwind path and need to remove
// some of the speculative frames.
- stepped = false;
in_device_map = true;
} else {
- bool finished;
- stepped = elf->Step(rel_pc, step_pc, regs_, process_memory_.get(), &finished);
- elf->GetLastError(&last_error_);
- if (stepped && finished) {
- break;
+ if (elf->StepIfSignalHandler(rel_pc, regs_, process_memory_.get())) {
+ stepped = true;
+ if (frame != nullptr) {
+ // Need to adjust the relative pc because the signal handler
+ // pc should not be adjusted.
+ frame->rel_pc = rel_pc;
+ frame->pc += pc_adjustment;
+ step_pc = rel_pc;
+ }
+ } else if (elf->Step(step_pc, regs_, process_memory_.get(), &finished)) {
+ stepped = true;
}
+ elf->GetLastError(&last_error_);
}
}
}
+ if (frame != nullptr) {
+ if (!resolve_names_ ||
+ !elf->GetFunctionName(step_pc, &frame->function_name, &frame->function_offset)) {
+ frame->function_name = "";
+ frame->function_offset = 0;
+ }
+ }
+
+ if (finished) {
+ break;
+ }
+
if (!stepped) {
if (return_address_attempt) {
// Only remove the speculative frame if there are more than two frames
diff --git a/libunwindstack/include/unwindstack/Elf.h b/libunwindstack/include/unwindstack/Elf.h
index ac94f10..56bf318 100644
--- a/libunwindstack/include/unwindstack/Elf.h
+++ b/libunwindstack/include/unwindstack/Elf.h
@@ -67,8 +67,9 @@
uint64_t GetRelPc(uint64_t pc, const MapInfo* map_info);
- bool Step(uint64_t rel_pc, uint64_t adjusted_rel_pc, Regs* regs, Memory* process_memory,
- bool* finished);
+ bool StepIfSignalHandler(uint64_t rel_pc, Regs* regs, Memory* process_memory);
+
+ bool Step(uint64_t rel_pc, Regs* regs, Memory* process_memory, bool* finished);
ElfInterface* CreateInterfaceFromMemory(Memory* memory);
diff --git a/libunwindstack/include/unwindstack/Error.h b/libunwindstack/include/unwindstack/Error.h
index 6ed0e0f..72ec454 100644
--- a/libunwindstack/include/unwindstack/Error.h
+++ b/libunwindstack/include/unwindstack/Error.h
@@ -29,6 +29,7 @@
ERROR_INVALID_MAP, // Unwind in an invalid map.
ERROR_MAX_FRAMES_EXCEEDED, // The number of frames exceed the total allowed.
ERROR_REPEATED_FRAME, // The last frame has the same pc/sp as the next.
+ ERROR_INVALID_ELF, // Unwind in an invalid elf.
};
struct ErrorData {
diff --git a/libunwindstack/include/unwindstack/Unwinder.h b/libunwindstack/include/unwindstack/Unwinder.h
index 8b01654..75be209 100644
--- a/libunwindstack/include/unwindstack/Unwinder.h
+++ b/libunwindstack/include/unwindstack/Unwinder.h
@@ -118,8 +118,7 @@
Unwinder(size_t max_frames) : max_frames_(max_frames) { frames_.reserve(max_frames); }
void FillInDexFrame();
- void FillInFrame(MapInfo* map_info, Elf* elf, uint64_t rel_pc, uint64_t func_pc,
- uint64_t pc_adjustment);
+ FrameData* FillInFrame(MapInfo* map_info, Elf* elf, uint64_t rel_pc, uint64_t pc_adjustment);
size_t max_frames_;
Maps* maps_;
diff --git a/libunwindstack/tests/ElfTest.cpp b/libunwindstack/tests/ElfTest.cpp
index 23c9cf8..c432d6d 100644
--- a/libunwindstack/tests/ElfTest.cpp
+++ b/libunwindstack/tests/ElfTest.cpp
@@ -132,8 +132,12 @@
uint64_t func_offset;
ASSERT_FALSE(elf.GetFunctionName(0, &name, &func_offset));
+ ASSERT_FALSE(elf.StepIfSignalHandler(0, nullptr, nullptr));
+ EXPECT_EQ(ERROR_INVALID_ELF, elf.GetLastErrorCode());
+
bool finished;
- ASSERT_FALSE(elf.Step(0, 0, nullptr, nullptr, &finished));
+ ASSERT_FALSE(elf.Step(0, nullptr, nullptr, &finished));
+ EXPECT_EQ(ERROR_INVALID_ELF, elf.GetLastErrorCode());
}
TEST_F(ElfTest, elf32_invalid_machine) {
@@ -295,9 +299,8 @@
}
elf.FakeSetValid(true);
- bool finished;
- ASSERT_TRUE(elf.Step(0x3000, 0x1000, ®s, &process_memory, &finished));
- EXPECT_FALSE(finished);
+ ASSERT_TRUE(elf.StepIfSignalHandler(0x3000, ®s, &process_memory));
+ EXPECT_EQ(ERROR_NONE, elf.GetLastErrorCode());
EXPECT_EQ(15U, regs.pc());
EXPECT_EQ(13U, regs.sp());
}
@@ -336,7 +339,7 @@
EXPECT_CALL(*interface, Step(0x1000, ®s, &process_memory, &finished))
.WillOnce(::testing::Return(true));
- ASSERT_TRUE(elf.Step(0x1004, 0x1000, ®s, &process_memory, &finished));
+ ASSERT_TRUE(elf.Step(0x1000, ®s, &process_memory, &finished));
}
TEST_F(ElfTest, get_global_invalid_elf) {
diff --git a/libunwindstack/tests/UnwindOfflineTest.cpp b/libunwindstack/tests/UnwindOfflineTest.cpp
index 02ba9c8..6c64c40 100644
--- a/libunwindstack/tests/UnwindOfflineTest.cpp
+++ b/libunwindstack/tests/UnwindOfflineTest.cpp
@@ -1215,7 +1215,7 @@
" #02 pc 0032bff3 libunwindstack_test (SignalOuterFunction+2)\n"
" #03 pc 0032fed3 libunwindstack_test "
"(unwindstack::SignalCallerHandler(int, siginfo*, void*)+26)\n"
- " #04 pc 00026528 libc.so\n"
+ " #04 pc 0002652c libc.so (__restore)\n"
" #05 pc 00000000 <unknown>\n"
" #06 pc 0032c2d9 libunwindstack_test (InnerFunction+736)\n"
" #07 pc 0032cc4f libunwindstack_test (MiddleFunction+42)\n"
@@ -1243,7 +1243,7 @@
EXPECT_EQ(0xf43d2ce8U, unwinder.frames()[2].sp);
EXPECT_EQ(0x2e59ed3U, unwinder.frames()[3].pc);
EXPECT_EQ(0xf43d2cf0U, unwinder.frames()[3].sp);
- EXPECT_EQ(0xf4136528U, unwinder.frames()[4].pc);
+ EXPECT_EQ(0xf413652cU, unwinder.frames()[4].pc);
EXPECT_EQ(0xf43d2d10U, unwinder.frames()[4].sp);
EXPECT_EQ(0U, unwinder.frames()[5].pc);
EXPECT_EQ(0xffcc0ee0U, unwinder.frames()[5].sp);
@@ -1326,7 +1326,7 @@
" #00 pc 000000000014ccbc linker64 (__dl_syscall+28)\n"
" #01 pc 000000000005426c linker64 "
"(__dl__ZL24debuggerd_signal_handleriP7siginfoPv+1128)\n"
- " #02 pc 00000000000008bc vdso.so\n"
+ " #02 pc 00000000000008c0 vdso.so (__kernel_rt_sigreturn)\n"
" #03 pc 00000000000846f4 libc.so (abort+172)\n"
" #04 pc 0000000000084ad4 libc.so (__assert2+36)\n"
" #05 pc 000000000003d5b4 ANGLEPrebuilt.apk!libfeature_support_angle.so (offset 0x4000) "
@@ -1338,7 +1338,7 @@
EXPECT_EQ(0x7df8ca3bf0ULL, unwinder.frames()[0].sp);
EXPECT_EQ(0x7e82b5726cULL, unwinder.frames()[1].pc);
EXPECT_EQ(0x7df8ca3bf0ULL, unwinder.frames()[1].sp);
- EXPECT_EQ(0x7e82b018bcULL, unwinder.frames()[2].pc);
+ EXPECT_EQ(0x7e82b018c0ULL, unwinder.frames()[2].pc);
EXPECT_EQ(0x7df8ca3da0ULL, unwinder.frames()[2].sp);
EXPECT_EQ(0x7e7eecc6f4ULL, unwinder.frames()[3].pc);
EXPECT_EQ(0x7dabf3db60ULL, unwinder.frames()[3].sp);
@@ -1366,7 +1366,7 @@
" #00 pc 000000000014ccbc linker64 (__dl_syscall+28)\n"
" #01 pc 000000000005426c linker64 "
"(__dl__ZL24debuggerd_signal_handleriP7siginfoPv+1128)\n"
- " #02 pc 00000000000008bc vdso.so\n"
+ " #02 pc 00000000000008c0 vdso.so (__kernel_rt_sigreturn)\n"
" #03 pc 00000000000846f4 libc.so (abort+172)\n"
" #04 pc 0000000000084ad4 libc.so (__assert2+36)\n"
" #05 pc 000000000003d5b4 ANGLEPrebuilt.apk (offset 0x21d5000)\n"
@@ -1377,7 +1377,7 @@
EXPECT_EQ(0x7df8ca3bf0ULL, unwinder.frames()[0].sp);
EXPECT_EQ(0x7e82b5726cULL, unwinder.frames()[1].pc);
EXPECT_EQ(0x7df8ca3bf0ULL, unwinder.frames()[1].sp);
- EXPECT_EQ(0x7e82b018bcULL, unwinder.frames()[2].pc);
+ EXPECT_EQ(0x7e82b018c0ULL, unwinder.frames()[2].pc);
EXPECT_EQ(0x7df8ca3da0ULL, unwinder.frames()[2].sp);
EXPECT_EQ(0x7e7eecc6f4ULL, unwinder.frames()[3].pc);
EXPECT_EQ(0x7dabf3db60ULL, unwinder.frames()[3].sp);
