Refactor the DwarfSection classes.
Modify the code for the no header sections because it turns out that
it is not okay to assume that the fdes are non-overlapping. It's necessary
to read the fdes in order and match as you go.
Modify the code so that it only reads until it finds the given pc rather than
reading all of the cie/fde entries at once.
Rewrote the tests to verify the new behavior.
Bug: 68998033
Bug: 110235461
Test: Ran libbacktrace/libunwindstack unit tests.
Test: Unwind the mediaserver process on a walleye and verify it
Test: unwinds properly.
Change-Id: I7bb59d1db72c13fa34caa9735ec34c1a60e20ed2
diff --git a/libunwindstack/DwarfEhFrameWithHdr.cpp b/libunwindstack/DwarfEhFrameWithHdr.cpp
index fd6a457..668527a 100644
--- a/libunwindstack/DwarfEhFrameWithHdr.cpp
+++ b/libunwindstack/DwarfEhFrameWithHdr.cpp
@@ -39,6 +39,7 @@
memory_.clear_text_offset();
memory_.set_data_offset(offset);
memory_.set_cur_offset(offset);
+ pc_offset_ = offset;
// Read the first four bytes all at once.
uint8_t data[4];
@@ -88,12 +89,22 @@
}
template <typename AddressType>
-const DwarfFde* DwarfEhFrameWithHdr<AddressType>::GetFdeFromIndex(size_t index) {
- const FdeInfo* info = GetFdeInfoFromIndex(index);
- if (info == nullptr) {
+const DwarfFde* DwarfEhFrameWithHdr<AddressType>::GetFdeFromPc(uint64_t pc) {
+ uint64_t fde_offset;
+ if (!GetFdeOffsetFromPc(pc, &fde_offset)) {
return nullptr;
}
- return this->GetFdeFromOffset(info->offset);
+ const DwarfFde* fde = this->GetFdeFromOffset(fde_offset);
+ if (fde == nullptr) {
+ return nullptr;
+ }
+
+ // Guaranteed pc >= pc_start, need to check pc in the fde range.
+ if (pc < fde->pc_end) {
+ return fde;
+ }
+ last_error_.code = DWARF_ERROR_ILLEGAL_STATE;
+ return nullptr;
}
template <typename AddressType>
@@ -241,6 +252,21 @@
}
}
+template <typename AddressType>
+void DwarfEhFrameWithHdr<AddressType>::GetFdes(std::vector<const DwarfFde*>* fdes) {
+ for (size_t i = 0; i < fde_count_; i++) {
+ const FdeInfo* info = GetFdeInfoFromIndex(i);
+ if (info == nullptr) {
+ break;
+ }
+ const DwarfFde* fde = this->GetFdeFromOffset(info->offset);
+ if (fde == nullptr) {
+ break;
+ }
+ fdes->push_back(fde);
+ }
+}
+
// Explicitly instantiate DwarfEhFrameWithHdr
template class DwarfEhFrameWithHdr<uint32_t>;
template class DwarfEhFrameWithHdr<uint64_t>;