Implement new DEX PC lookup scheme.
GDB wasn't handling the old one gracefully.
- Create a RegsInfo structure that can be used to properly eval expression
data.
- Remove the versions on Dwarf ops. It doesn't work the in the real world
and doesn't add useful information.
- Fix dex pc frame number bug.
Test: testrunner.py -j40 --host --cdex-fast -t 137
Test: libunwindstack_test
Test: All unit tests pass.
Change-Id: Iac4fea651b81cb6087fd237a9a5027a352a49245
diff --git a/libunwindstack/DwarfSection.cpp b/libunwindstack/DwarfSection.cpp
index 4e94f88..7649798 100644
--- a/libunwindstack/DwarfSection.cpp
+++ b/libunwindstack/DwarfSection.cpp
@@ -26,16 +26,14 @@
#include <unwindstack/Regs.h>
#include "DwarfCfa.h"
-#include "DwarfEncoding.h"
-#include "DwarfOp.h"
-
#include "DwarfDebugFrame.h"
#include "DwarfEhFrame.h"
+#include "DwarfEncoding.h"
+#include "DwarfOp.h"
+#include "RegsInfo.h"
namespace unwindstack {
-constexpr uint64_t DEX_PC_REG = 0x20444558;
-
DwarfSection::DwarfSection(Memory* memory) : memory_(memory) {}
const DwarfFde* DwarfSection::GetFdeFromPc(uint64_t pc) {
@@ -75,14 +73,17 @@
}
template <typename AddressType>
-bool DwarfSectionImpl<AddressType>::EvalExpression(const DwarfLocation& loc, uint8_t version,
- Memory* regular_memory, AddressType* value) {
+bool DwarfSectionImpl<AddressType>::EvalExpression(const DwarfLocation& loc, Memory* regular_memory,
+ AddressType* value,
+ RegsInfo<AddressType>* regs_info,
+ bool* is_dex_pc) {
DwarfOp<AddressType> op(&memory_, regular_memory);
+ op.set_regs_info(regs_info);
// Need to evaluate the op data.
- uint64_t start = loc.values[1];
- uint64_t end = start + loc.values[0];
- if (!op.Eval(start, end, version)) {
+ uint64_t end = loc.values[1];
+ uint64_t start = end - loc.values[0];
+ if (!op.Eval(start, end)) {
last_error_ = op.last_error();
return false;
}
@@ -96,6 +97,9 @@
return false;
}
*value = op.StackAt(0);
+ if (is_dex_pc != nullptr && op.dex_pc_set()) {
+ *is_dex_pc = true;
+ }
return true;
}
@@ -103,12 +107,10 @@
struct EvalInfo {
const dwarf_loc_regs_t* loc_regs;
const DwarfCie* cie;
- RegsImpl<AddressType>* cur_regs;
Memory* regular_memory;
AddressType cfa;
bool return_address_undefined = false;
- uint64_t reg_map = 0;
- AddressType reg_values[64];
+ RegsInfo<AddressType> regs_info;
};
template <typename AddressType>
@@ -129,32 +131,18 @@
break;
case DWARF_LOCATION_REGISTER: {
uint32_t cur_reg = loc->values[0];
- if (cur_reg >= eval_info->cur_regs->total_regs()) {
+ if (cur_reg >= eval_info->regs_info.Total()) {
last_error_.code = DWARF_ERROR_ILLEGAL_VALUE;
return false;
}
- AddressType* cur_reg_ptr = &(*eval_info->cur_regs)[cur_reg];
- const auto& entry = eval_info->loc_regs->find(cur_reg);
- if (entry != eval_info->loc_regs->end()) {
- if (!(eval_info->reg_map & (1 << cur_reg))) {
- eval_info->reg_map |= 1 << cur_reg;
- eval_info->reg_values[cur_reg] = *cur_reg_ptr;
- if (!EvalRegister(&entry->second, cur_reg, cur_reg_ptr, eval_info)) {
- return false;
- }
- }
-
- // Use the register value from before any evaluations.
- *reg_ptr = eval_info->reg_values[cur_reg] + loc->values[1];
- } else {
- *reg_ptr = *cur_reg_ptr + loc->values[1];
- }
+ *reg_ptr = eval_info->regs_info.Get(cur_reg) + loc->values[1];
break;
}
case DWARF_LOCATION_EXPRESSION:
case DWARF_LOCATION_VAL_EXPRESSION: {
AddressType value;
- if (!EvalExpression(*loc, eval_info->cie->version, regular_memory, &value)) {
+ bool is_dex_pc = false;
+ if (!EvalExpression(*loc, regular_memory, &value, &eval_info->regs_info, &is_dex_pc)) {
return false;
}
if (loc->type == DWARF_LOCATION_EXPRESSION) {
@@ -165,6 +153,9 @@
}
} else {
*reg_ptr = value;
+ if (is_dex_pc) {
+ eval_info->regs_info.regs->set_dex_pc(value);
+ }
}
break;
}
@@ -201,8 +192,10 @@
AddressType prev_cfa = regs->sp();
- EvalInfo<AddressType> eval_info{
- .loc_regs = &loc_regs, .cie = cie, .regular_memory = regular_memory, .cur_regs = cur_regs};
+ EvalInfo<AddressType> eval_info{.loc_regs = &loc_regs,
+ .cie = cie,
+ .regular_memory = regular_memory,
+ .regs_info = RegsInfo<AddressType>(cur_regs)};
const DwarfLocation* loc = &cfa_entry->second;
// Only a few location types are valid for the cfa.
switch (loc->type) {
@@ -224,7 +217,7 @@
case DWARF_LOCATION_EXPRESSION:
case DWARF_LOCATION_VAL_EXPRESSION: {
AddressType value;
- if (!EvalExpression(*loc, cie->version, regular_memory, &value)) {
+ if (!EvalExpression(*loc, regular_memory, &value, &eval_info.regs_info, nullptr)) {
return false;
}
if (loc->type == DWARF_LOCATION_EXPRESSION) {
@@ -249,28 +242,15 @@
if (reg == CFA_REG) continue;
AddressType* reg_ptr;
- AddressType dex_pc = 0;
- if (reg == DEX_PC_REG) {
- // Special register that indicates this is a dex pc.
- dex_pc = 0;
- reg_ptr = &dex_pc;
- } else if (reg >= cur_regs->total_regs() || eval_info.reg_map & (1 << reg)) {
- // Skip this unknown register, or a register that has already been
- // processed.
+ if (reg >= cur_regs->total_regs()) {
+ // Skip this unknown register.
continue;
- } else {
- reg_ptr = &(*cur_regs)[reg];
- eval_info.reg_map |= 1 << reg;
- eval_info.reg_values[reg] = *reg_ptr;
}
+ reg_ptr = eval_info.regs_info.Save(reg);
if (!EvalRegister(&entry.second, reg, reg_ptr, &eval_info)) {
return false;
}
-
- if (reg == DEX_PC_REG) {
- cur_regs->set_dex_pc(dex_pc);
- }
}
// Find the return address location.