[x86] Fix issues with a realigned stack in MSVC compiled applications
Summary:
This patch fixes issues with a stack realignment.
MSVC maintains two frame pointers (`ebx` and `ebp`) for a realigned stack - one
is used for access to function parameters, while another is used for access to
locals. To support this the patch:
- adds an alternative frame pointer (`ebx`);
- considers stack realignment instructions (e.g. `and esp, -32`);
- along with CFA (Canonical Frame Address) which point to the position next to
the saved return address (or to the first parameter on the stack) introduces
AFA (Aligned Frame Address) which points to the position of the stack pointer
right after realignment. AFA is used for access to registers saved after the
realignment (see the test);
Here is an example of the code with the realignment:
```
struct __declspec(align(256)) OverAligned {
char c;
};
void foo(int foo_arg) {
OverAligned oa_foo = { 1 };
auto aaa_foo = 1234;
}
void bar(int bar_arg) {
OverAligned oa_bar = { 2 };
auto aaa_bar = 5678;
foo(1111);
}
int main() {
bar(2222);
return 0;
}
```
and here is the `bar` disassembly:
```
push ebx
mov ebx, esp
sub esp, 8
and esp, -100h
add esp, 4
push ebp
mov ebp, [ebx+4]
mov [esp+4], ebp
mov ebp, esp
sub esp, 200h
mov byte ptr [ebp-200h], 2
mov dword ptr [ebp-4], 5678
push 1111 ; foo_arg
call j_?foo@@YAXH@Z ; foo(int)
add esp, 4
mov esp, ebp
pop ebp
mov esp, ebx
pop ebx
retn
```
Reviewers: labath, zturner, jasonmolenda, stella.stamenova
Reviewed By: jasonmolenda
Subscribers: abidh, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D53435
llvm-svn: 345577
diff --git a/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp b/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp
index e943c3d..3a1f2fb 100644
--- a/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp
+++ b/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp
@@ -54,7 +54,8 @@
: RegisterContext(thread, frame_number), m_thread(thread),
m_fast_unwind_plan_sp(), m_full_unwind_plan_sp(),
m_fallback_unwind_plan_sp(), m_all_registers_available(false),
- m_frame_type(-1), m_cfa(LLDB_INVALID_ADDRESS), m_start_pc(),
+ m_frame_type(-1), m_cfa(LLDB_INVALID_ADDRESS),
+ m_afa(LLDB_INVALID_ADDRESS), m_start_pc(),
m_current_pc(), m_current_offset(0), m_current_offset_backed_up_one(0),
m_sym_ctx(sym_ctx), m_sym_ctx_valid(false), m_frame_number(frame_number),
m_registers(), m_parent_unwind(unwind_lldb) {
@@ -228,7 +229,7 @@
return;
}
- if (!ReadCFAValueForRow(row_register_kind, active_row, m_cfa)) {
+ if (!ReadFrameAddress(row_register_kind, active_row->GetCFAValue(), m_cfa)) {
// Try the fall back unwind plan since the
// full unwind plan failed.
FuncUnwindersSP func_unwinders_sp;
@@ -256,12 +257,14 @@
m_frame_type = eNotAValidFrame;
return;
}
- }
+ } else
+ ReadFrameAddress(row_register_kind, active_row->GetAFAValue(), m_afa);
UnwindLogMsg("initialized frame current pc is 0x%" PRIx64 " cfa is 0x%" PRIx64
- " using %s UnwindPlan",
+ " afa is 0x%" PRIx64 " using %s UnwindPlan",
(uint64_t)m_current_pc.GetLoadAddress(exe_ctx.GetTargetPtr()),
(uint64_t)m_cfa,
+ (uint64_t)m_afa,
m_full_unwind_plan_sp->GetSourceName().GetCString());
}
@@ -379,7 +382,7 @@
RegisterKind row_register_kind = m_full_unwind_plan_sp->GetRegisterKind();
UnwindPlan::RowSP row = m_full_unwind_plan_sp->GetRowForFunctionOffset(0);
if (row.get()) {
- if (!ReadCFAValueForRow(row_register_kind, row, m_cfa)) {
+ if (!ReadFrameAddress(row_register_kind, row->GetCFAValue(), m_cfa)) {
UnwindLogMsg("failed to get cfa value");
if (m_frame_type != eSkipFrame) // don't override eSkipFrame
{
@@ -388,6 +391,8 @@
return;
}
+ ReadFrameAddress(row_register_kind, row->GetAFAValue(), m_afa);
+
// A couple of sanity checks..
if (m_cfa == LLDB_INVALID_ADDRESS || m_cfa == 0 || m_cfa == 1) {
UnwindLogMsg("could not find a valid cfa address");
@@ -420,7 +425,8 @@
}
}
- UnwindLogMsg("initialized frame cfa is 0x%" PRIx64, (uint64_t)m_cfa);
+ UnwindLogMsg("initialized frame cfa is 0x%" PRIx64 " afa is 0x%" PRIx64,
+ (uint64_t)m_cfa, (uint64_t)m_afa);
return;
}
m_frame_type = eNotAValidFrame;
@@ -584,13 +590,15 @@
return;
}
- if (!ReadCFAValueForRow(row_register_kind, active_row, m_cfa)) {
+ if (!ReadFrameAddress(row_register_kind, active_row->GetCFAValue(), m_cfa)) {
UnwindLogMsg("failed to get cfa");
m_frame_type = eNotAValidFrame;
return;
}
- UnwindLogMsg("m_cfa = 0x%" PRIx64, m_cfa);
+ ReadFrameAddress(row_register_kind, active_row->GetAFAValue(), m_afa);
+
+ UnwindLogMsg("m_cfa = 0x%" PRIx64 " m_afa = 0x%" PRIx64, m_cfa, m_afa);
if (CheckIfLoopingStack()) {
TryFallbackUnwindPlan();
@@ -603,9 +611,10 @@
}
UnwindLogMsg("initialized frame current pc is 0x%" PRIx64
- " cfa is 0x%" PRIx64,
+ " cfa is 0x%" PRIx64 " afa is 0x%" PRIx64,
(uint64_t)m_current_pc.GetLoadAddress(exe_ctx.GetTargetPtr()),
- (uint64_t)m_cfa);
+ (uint64_t)m_cfa,
+ (uint64_t)m_afa);
}
bool RegisterContextLLDB::CheckIfLoopingStack() {
@@ -1314,8 +1323,8 @@
unwindplan_regloc)) {
can_fetch_pc_value = true;
}
- if (ReadCFAValueForRow(unwindplan_registerkind, active_row,
- cfa_value)) {
+ if (ReadFrameAddress(unwindplan_registerkind,
+ active_row->GetCFAValue(), cfa_value)) {
can_fetch_cfa = true;
}
}
@@ -1444,6 +1453,36 @@
return UnwindLLDB::RegisterSearchResult::eRegisterFound;
}
+ if (unwindplan_regloc.IsAFAPlusOffset()) {
+ if (m_afa == LLDB_INVALID_ADDRESS)
+ return UnwindLLDB::RegisterSearchResult::eRegisterNotFound;
+
+ int offset = unwindplan_regloc.GetOffset();
+ regloc.type = UnwindLLDB::RegisterLocation::eRegisterValueInferred;
+ regloc.location.inferred_value = m_afa + offset;
+ m_registers[regnum.GetAsKind(eRegisterKindLLDB)] = regloc;
+ UnwindLogMsg("supplying caller's register %s (%d), value is AFA plus "
+ "offset %d [value is 0x%" PRIx64 "]",
+ regnum.GetName(), regnum.GetAsKind(eRegisterKindLLDB), offset,
+ regloc.location.inferred_value);
+ return UnwindLLDB::RegisterSearchResult::eRegisterFound;
+ }
+
+ if (unwindplan_regloc.IsAtAFAPlusOffset()) {
+ if (m_afa == LLDB_INVALID_ADDRESS)
+ return UnwindLLDB::RegisterSearchResult::eRegisterNotFound;
+
+ int offset = unwindplan_regloc.GetOffset();
+ regloc.type = UnwindLLDB::RegisterLocation::eRegisterSavedAtMemoryLocation;
+ regloc.location.target_memory_location = m_afa + offset;
+ m_registers[regnum.GetAsKind(eRegisterKindLLDB)] = regloc;
+ UnwindLogMsg("supplying caller's register %s (%d) from the stack, saved at "
+ "AFA plus offset %d [saved at 0x%" PRIx64 "]",
+ regnum.GetName(), regnum.GetAsKind(eRegisterKindLLDB), offset,
+ regloc.location.target_memory_location);
+ return UnwindLLDB::RegisterSearchResult::eRegisterFound;
+ }
+
if (unwindplan_regloc.IsInOtherRegister()) {
uint32_t unwindplan_regnum = unwindplan_regloc.GetRegisterNumber();
RegisterNumber row_regnum(m_thread, unwindplan_registerkind,
@@ -1558,7 +1597,6 @@
addr_t old_caller_pc_value = LLDB_INVALID_ADDRESS;
addr_t new_caller_pc_value = LLDB_INVALID_ADDRESS;
- addr_t old_this_frame_cfa_value = m_cfa;
UnwindLLDB::RegisterLocation regloc;
if (SavedLocationForRegister(pc_regnum.GetAsKind(eRegisterKindLLDB),
regloc) ==
@@ -1588,6 +1626,7 @@
// the value of the m_cfa ivar. Save is down below a bit in 'old_cfa'.
UnwindPlanSP original_full_unwind_plan_sp = m_full_unwind_plan_sp;
addr_t old_cfa = m_cfa;
+ addr_t old_afa = m_afa;
m_registers.clear();
@@ -1598,19 +1637,21 @@
if (active_row &&
active_row->GetCFAValue().GetValueType() !=
- UnwindPlan::Row::CFAValue::unspecified) {
+ UnwindPlan::Row::FAValue::unspecified) {
addr_t new_cfa;
- if (!ReadCFAValueForRow(m_fallback_unwind_plan_sp->GetRegisterKind(),
- active_row, new_cfa) ||
+ if (!ReadFrameAddress(m_fallback_unwind_plan_sp->GetRegisterKind(),
+ active_row->GetCFAValue(), new_cfa) ||
new_cfa == 0 || new_cfa == 1 || new_cfa == LLDB_INVALID_ADDRESS) {
UnwindLogMsg("failed to get cfa with fallback unwindplan");
m_fallback_unwind_plan_sp.reset();
m_full_unwind_plan_sp = original_full_unwind_plan_sp;
- m_cfa = old_cfa;
return false;
}
m_cfa = new_cfa;
+ ReadFrameAddress(m_fallback_unwind_plan_sp->GetRegisterKind(),
+ active_row->GetAFAValue(), m_afa);
+
if (SavedLocationForRegister(pc_regnum.GetAsKind(eRegisterKindLLDB),
regloc) ==
UnwindLLDB::RegisterSearchResult::eRegisterFound) {
@@ -1631,19 +1672,18 @@
m_fallback_unwind_plan_sp.reset();
m_full_unwind_plan_sp = original_full_unwind_plan_sp;
m_cfa = old_cfa;
+ m_afa = old_afa;
return false;
}
- if (old_caller_pc_value != LLDB_INVALID_ADDRESS) {
- if (old_caller_pc_value == new_caller_pc_value &&
- new_cfa == old_this_frame_cfa_value) {
- UnwindLogMsg("fallback unwind plan got the same values for this frame "
- "CFA and caller frame pc, not using");
- m_fallback_unwind_plan_sp.reset();
- m_full_unwind_plan_sp = original_full_unwind_plan_sp;
- m_cfa = old_cfa;
- return false;
- }
+ if (old_caller_pc_value == new_caller_pc_value &&
+ m_cfa == old_cfa &&
+ m_afa == old_afa) {
+ UnwindLogMsg("fallback unwind plan got the same values for this frame "
+ "CFA and caller frame pc, not using");
+ m_fallback_unwind_plan_sp.reset();
+ m_full_unwind_plan_sp = original_full_unwind_plan_sp;
+ return false;
}
UnwindLogMsg("trying to unwind from this function with the UnwindPlan '%s' "
@@ -1677,16 +1717,19 @@
if (active_row &&
active_row->GetCFAValue().GetValueType() !=
- UnwindPlan::Row::CFAValue::unspecified) {
+ UnwindPlan::Row::FAValue::unspecified) {
addr_t new_cfa;
- if (!ReadCFAValueForRow(m_fallback_unwind_plan_sp->GetRegisterKind(),
- active_row, new_cfa) ||
+ if (!ReadFrameAddress(m_fallback_unwind_plan_sp->GetRegisterKind(),
+ active_row->GetCFAValue(), new_cfa) ||
new_cfa == 0 || new_cfa == 1 || new_cfa == LLDB_INVALID_ADDRESS) {
UnwindLogMsg("failed to get cfa with fallback unwindplan");
m_fallback_unwind_plan_sp.reset();
return false;
}
+ ReadFrameAddress(m_fallback_unwind_plan_sp->GetRegisterKind(),
+ active_row->GetAFAValue(), m_afa);
+
m_full_unwind_plan_sp = m_fallback_unwind_plan_sp;
m_fallback_unwind_plan_sp.reset();
@@ -1701,18 +1744,18 @@
return false;
}
-bool RegisterContextLLDB::ReadCFAValueForRow(
- lldb::RegisterKind row_register_kind, const UnwindPlan::RowSP &row,
- addr_t &cfa_value) {
+bool RegisterContextLLDB::ReadFrameAddress(
+ lldb::RegisterKind row_register_kind, UnwindPlan::Row::FAValue &fa,
+ addr_t &address) {
RegisterValue reg_value;
- cfa_value = LLDB_INVALID_ADDRESS;
+ address = LLDB_INVALID_ADDRESS;
addr_t cfa_reg_contents;
- switch (row->GetCFAValue().GetValueType()) {
- case UnwindPlan::Row::CFAValue::isRegisterDereferenced: {
+ switch (fa.GetValueType()) {
+ case UnwindPlan::Row::FAValue::isRegisterDereferenced: {
RegisterNumber cfa_reg(m_thread, row_register_kind,
- row->GetCFAValue().GetRegisterNumber());
+ fa.GetRegisterNumber());
if (ReadGPRValue(cfa_reg, cfa_reg_contents)) {
const RegisterInfo *reg_info =
GetRegisterInfoAtIndex(cfa_reg.GetAsKind(eRegisterKindLLDB));
@@ -1721,12 +1764,12 @@
Status error = ReadRegisterValueFromMemory(
reg_info, cfa_reg_contents, reg_info->byte_size, reg_value);
if (error.Success()) {
- cfa_value = reg_value.GetAsUInt64();
+ address = reg_value.GetAsUInt64();
UnwindLogMsg(
"CFA value via dereferencing reg %s (%d): reg has val 0x%" PRIx64
", CFA value is 0x%" PRIx64,
cfa_reg.GetName(), cfa_reg.GetAsKind(eRegisterKindLLDB),
- cfa_reg_contents, cfa_value);
+ cfa_reg_contents, address);
return true;
} else {
UnwindLogMsg("Tried to deref reg %s (%d) [0x%" PRIx64
@@ -1738,9 +1781,9 @@
}
break;
}
- case UnwindPlan::Row::CFAValue::isRegisterPlusOffset: {
+ case UnwindPlan::Row::FAValue::isRegisterPlusOffset: {
RegisterNumber cfa_reg(m_thread, row_register_kind,
- row->GetCFAValue().GetRegisterNumber());
+ fa.GetRegisterNumber());
if (ReadGPRValue(cfa_reg, cfa_reg_contents)) {
if (cfa_reg_contents == LLDB_INVALID_ADDRESS || cfa_reg_contents == 0 ||
cfa_reg_contents == 1) {
@@ -1751,35 +1794,35 @@
cfa_reg_contents = LLDB_INVALID_ADDRESS;
return false;
}
- cfa_value = cfa_reg_contents + row->GetCFAValue().GetOffset();
+ address = cfa_reg_contents + fa.GetOffset();
UnwindLogMsg(
"CFA is 0x%" PRIx64 ": Register %s (%d) contents are 0x%" PRIx64
", offset is %d",
- cfa_value, cfa_reg.GetName(), cfa_reg.GetAsKind(eRegisterKindLLDB),
- cfa_reg_contents, row->GetCFAValue().GetOffset());
+ address, cfa_reg.GetName(), cfa_reg.GetAsKind(eRegisterKindLLDB),
+ cfa_reg_contents, fa.GetOffset());
return true;
}
break;
}
- case UnwindPlan::Row::CFAValue::isDWARFExpression: {
+ case UnwindPlan::Row::FAValue::isDWARFExpression: {
ExecutionContext exe_ctx(m_thread.shared_from_this());
Process *process = exe_ctx.GetProcessPtr();
- DataExtractor dwarfdata(row->GetCFAValue().GetDWARFExpressionBytes(),
- row->GetCFAValue().GetDWARFExpressionLength(),
+ DataExtractor dwarfdata(fa.GetDWARFExpressionBytes(),
+ fa.GetDWARFExpressionLength(),
process->GetByteOrder(),
process->GetAddressByteSize());
ModuleSP opcode_ctx;
DWARFExpression dwarfexpr(opcode_ctx, dwarfdata, nullptr, 0,
- row->GetCFAValue().GetDWARFExpressionLength());
+ fa.GetDWARFExpressionLength());
dwarfexpr.SetRegisterKind(row_register_kind);
Value result;
Status error;
if (dwarfexpr.Evaluate(&exe_ctx, this, 0, nullptr, nullptr, result,
&error)) {
- cfa_value = result.GetScalar().ULongLong();
+ address = result.GetScalar().ULongLong();
UnwindLogMsg("CFA value set by DWARF expression is 0x%" PRIx64,
- cfa_value);
+ address);
return true;
}
UnwindLogMsg("Failed to set CFA value via DWARF expression: %s",
diff --git a/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.h b/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.h
index 7e9e77d..d436bc1 100644
--- a/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.h
+++ b/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.h
@@ -192,9 +192,9 @@
bool ReadGPRValue(const RegisterNumber ®_num, lldb::addr_t &value);
- // Get the CFA register for a given frame.
- bool ReadCFAValueForRow(lldb::RegisterKind register_kind,
- const UnwindPlan::RowSP &row, lldb::addr_t &value);
+ // Get the Frame Address register for a given frame.
+ bool ReadFrameAddress(lldb::RegisterKind register_kind,
+ UnwindPlan::Row::FAValue &fa, lldb::addr_t &address);
lldb::UnwindPlanSP GetFastUnwindPlanForFrame();
@@ -225,6 +225,7 @@
int m_frame_type; // enum FrameType
lldb::addr_t m_cfa;
+ lldb::addr_t m_afa;
lldb_private::Address m_start_pc;
lldb_private::Address m_current_pc;
diff --git a/lldb/source/Plugins/UnwindAssembly/x86/UnwindAssembly-x86.cpp b/lldb/source/Plugins/UnwindAssembly/x86/UnwindAssembly-x86.cpp
index 327d0b0..9295a09 100644
--- a/lldb/source/Plugins/UnwindAssembly/x86/UnwindAssembly-x86.cpp
+++ b/lldb/source/Plugins/UnwindAssembly/x86/UnwindAssembly-x86.cpp
@@ -92,7 +92,7 @@
// assembly parsing instead.
if (first_row->GetCFAValue().GetValueType() !=
- UnwindPlan::Row::CFAValue::isRegisterPlusOffset ||
+ UnwindPlan::Row::FAValue::isRegisterPlusOffset ||
RegisterNumber(thread, unwind_plan.GetRegisterKind(),
first_row->GetCFAValue().GetRegisterNumber()) !=
sp_regnum ||
diff --git a/lldb/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp b/lldb/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp
index 10a5698..eb19898 100644
--- a/lldb/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp
+++ b/lldb/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp
@@ -59,6 +59,7 @@
m_machine_ip_regnum = k_machine_eip;
m_machine_sp_regnum = k_machine_esp;
m_machine_fp_regnum = k_machine_ebp;
+ m_machine_alt_fp_regnum = k_machine_ebx;
m_wordsize = 4;
struct lldb_reg_info reginfo;
@@ -84,6 +85,7 @@
m_machine_ip_regnum = k_machine_rip;
m_machine_sp_regnum = k_machine_rsp;
m_machine_fp_regnum = k_machine_rbp;
+ m_machine_alt_fp_regnum = k_machine_rbx;
m_wordsize = 8;
struct lldb_reg_info reginfo;
@@ -135,6 +137,8 @@
m_lldb_sp_regnum = lldb_regno;
if (machine_regno_to_lldb_regno(m_machine_fp_regnum, lldb_regno))
m_lldb_fp_regnum = lldb_regno;
+ if (machine_regno_to_lldb_regno(m_machine_alt_fp_regnum, lldb_regno))
+ m_lldb_alt_fp_regnum = lldb_regno;
if (machine_regno_to_lldb_regno(m_machine_ip_regnum, lldb_regno))
m_lldb_ip_regnum = lldb_regno;
@@ -160,6 +164,7 @@
m_machine_ip_regnum = k_machine_eip;
m_machine_sp_regnum = k_machine_esp;
m_machine_fp_regnum = k_machine_ebp;
+ m_machine_alt_fp_regnum = k_machine_ebx;
m_wordsize = 4;
struct lldb_reg_info reginfo;
@@ -185,6 +190,7 @@
m_machine_ip_regnum = k_machine_rip;
m_machine_sp_regnum = k_machine_rsp;
m_machine_fp_regnum = k_machine_rbp;
+ m_machine_alt_fp_regnum = k_machine_rbx;
m_wordsize = 8;
struct lldb_reg_info reginfo;
@@ -239,6 +245,8 @@
m_lldb_sp_regnum = lldb_regno;
if (machine_regno_to_lldb_regno(m_machine_fp_regnum, lldb_regno))
m_lldb_fp_regnum = lldb_regno;
+ if (machine_regno_to_lldb_regno(m_machine_alt_fp_regnum, lldb_regno))
+ m_lldb_alt_fp_regnum = lldb_regno;
if (machine_regno_to_lldb_regno(m_machine_ip_regnum, lldb_regno))
m_lldb_ip_regnum = lldb_regno;
@@ -387,6 +395,45 @@
return false;
}
+// movq %rsp, %rbx [0x48 0x8b 0xdc] or [0x48 0x89 0xe3]
+// movl %esp, %ebx [0x8b 0xdc] or [0x89 0xe3]
+bool x86AssemblyInspectionEngine::mov_rsp_rbx_pattern_p() {
+ uint8_t *p = m_cur_insn;
+ if (m_wordsize == 8 && *p == 0x48)
+ p++;
+ if (*(p) == 0x8b && *(p + 1) == 0xdc)
+ return true;
+ if (*(p) == 0x89 && *(p + 1) == 0xe3)
+ return true;
+ return false;
+}
+
+// movq %rbp, %rsp [0x48 0x8b 0xe5] or [0x48 0x89 0xec]
+// movl %ebp, %esp [0x8b 0xe5] or [0x89 0xec]
+bool x86AssemblyInspectionEngine::mov_rbp_rsp_pattern_p() {
+ uint8_t *p = m_cur_insn;
+ if (m_wordsize == 8 && *p == 0x48)
+ p++;
+ if (*(p) == 0x8b && *(p + 1) == 0xe5)
+ return true;
+ if (*(p) == 0x89 && *(p + 1) == 0xec)
+ return true;
+ return false;
+}
+
+// movq %rbx, %rsp [0x48 0x8b 0xe3] or [0x48 0x89 0xdc]
+// movl %ebx, %esp [0x8b 0xe3] or [0x89 0xdc]
+bool x86AssemblyInspectionEngine::mov_rbx_rsp_pattern_p() {
+ uint8_t *p = m_cur_insn;
+ if (m_wordsize == 8 && *p == 0x48)
+ p++;
+ if (*(p) == 0x8b && *(p + 1) == 0xe3)
+ return true;
+ if (*(p) == 0x89 && *(p + 1) == 0xdc)
+ return true;
+ return false;
+}
+
// subq $0x20, %rsp
bool x86AssemblyInspectionEngine::sub_rsp_pattern_p(int &amount) {
uint8_t *p = m_cur_insn;
@@ -476,6 +523,46 @@
return false;
}
+// lea -0x28(%ebx), %esp
+// (32-bit and 64-bit variants, 8-bit and 32-bit displacement)
+bool x86AssemblyInspectionEngine::lea_rbx_rsp_pattern_p(int &amount) {
+ uint8_t *p = m_cur_insn;
+ if (m_wordsize == 8 && *p == 0x48)
+ p++;
+
+ // Check opcode
+ if (*p != 0x8d)
+ return false;
+ ++p;
+
+ // 8 bit displacement
+ if (*p == 0x63) {
+ amount = (int8_t)p[1];
+ return true;
+ }
+
+ // 32 bit displacement
+ if (*p == 0xa3) {
+ amount = (int32_t)extract_4(p + 1);
+ return true;
+ }
+
+ return false;
+}
+
+// and -0xfffffff0, %esp
+// (32-bit and 64-bit variants, 8-bit and 32-bit displacement)
+bool x86AssemblyInspectionEngine::and_rsp_pattern_p() {
+ uint8_t *p = m_cur_insn;
+ if (m_wordsize == 8 && *p == 0x48)
+ p++;
+
+ if (*p != 0x81 && *p != 0x83)
+ return false;
+
+ return *++p == 0xe4;
+}
+
// popq %rbx
// popl %ebx
bool x86AssemblyInspectionEngine::pop_reg_p(int ®no) {
@@ -640,7 +727,8 @@
return false;
addr_t current_func_text_offset = 0;
- int current_sp_bytes_offset_from_cfa = 0;
+ int current_sp_bytes_offset_from_fa = 0;
+ bool is_aligned = false;
UnwindPlan::Row::RegisterLocation initial_regloc;
UnwindPlan::RowSP row(new UnwindPlan::Row);
@@ -657,8 +745,8 @@
row->SetRegisterInfo(m_lldb_sp_regnum, initial_regloc);
// saved instruction pointer can be found at CFA - wordsize.
- current_sp_bytes_offset_from_cfa = m_wordsize;
- initial_regloc.SetAtCFAPlusOffset(-current_sp_bytes_offset_from_cfa);
+ current_sp_bytes_offset_from_fa = m_wordsize;
+ initial_regloc.SetAtCFAPlusOffset(-current_sp_bytes_offset_from_fa);
row->SetRegisterInfo(m_lldb_ip_regnum, initial_regloc);
unwind_plan.AppendRow(row);
@@ -682,6 +770,7 @@
UnwindPlan::RowSP prologue_completed_row; // copy of prologue row of CFI
int prologue_completed_sp_bytes_offset_from_cfa; // The sp value before the
// epilogue started executed
+ bool prologue_completed_is_aligned;
std::vector<bool> prologue_completed_saved_registers;
while (current_func_text_offset < size) {
@@ -701,20 +790,57 @@
break;
}
- if (push_rbp_pattern_p()) {
- current_sp_bytes_offset_from_cfa += m_wordsize;
- row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
- UnwindPlan::Row::RegisterLocation regloc;
- regloc.SetAtCFAPlusOffset(-row->GetCFAValue().GetOffset());
- row->SetRegisterInfo(m_lldb_fp_regnum, regloc);
- saved_registers[m_machine_fp_regnum] = true;
+ auto &cfa_value = row->GetCFAValue();
+ auto &afa_value = row->GetAFAValue();
+ auto fa_value_ptr = is_aligned ? &afa_value : &cfa_value;
+
+ if (mov_rsp_rbp_pattern_p()) {
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_sp_regnum) {
+ fa_value_ptr->SetIsRegisterPlusOffset(
+ m_lldb_fp_regnum, fa_value_ptr->GetOffset());
+ row_updated = true;
+ }
+ }
+
+ else if (mov_rsp_rbx_pattern_p()) {
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_sp_regnum) {
+ fa_value_ptr->SetIsRegisterPlusOffset(
+ m_lldb_alt_fp_regnum, fa_value_ptr->GetOffset());
+ row_updated = true;
+ }
+ }
+
+ else if (and_rsp_pattern_p()) {
+ current_sp_bytes_offset_from_fa = 0;
+ afa_value.SetIsRegisterPlusOffset(
+ m_lldb_sp_regnum, current_sp_bytes_offset_from_fa);
+ fa_value_ptr = &afa_value;
+ is_aligned = true;
row_updated = true;
}
- else if (mov_rsp_rbp_pattern_p()) {
- row->GetCFAValue().SetIsRegisterPlusOffset(
- m_lldb_fp_regnum, row->GetCFAValue().GetOffset());
- row_updated = true;
+ else if (mov_rbp_rsp_pattern_p()) {
+ if (is_aligned && cfa_value.GetRegisterNumber() == m_lldb_fp_regnum)
+ {
+ is_aligned = false;
+ fa_value_ptr = &cfa_value;
+ afa_value.SetUnspecified();
+ row_updated = true;
+ }
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_fp_regnum)
+ current_sp_bytes_offset_from_fa = fa_value_ptr->GetOffset();
+ }
+
+ else if (mov_rbx_rsp_pattern_p()) {
+ if (is_aligned && cfa_value.GetRegisterNumber() == m_lldb_alt_fp_regnum)
+ {
+ is_aligned = false;
+ fa_value_ptr = &cfa_value;
+ afa_value.SetUnspecified();
+ row_updated = true;
+ }
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_alt_fp_regnum)
+ current_sp_bytes_offset_from_fa = fa_value_ptr->GetOffset();
}
// This is the start() function (or a pthread equivalent), it starts with a
@@ -726,12 +852,12 @@
}
else if (push_reg_p(machine_regno)) {
- current_sp_bytes_offset_from_cfa += m_wordsize;
- // the PUSH instruction has moved the stack pointer - if the CFA is set
+ current_sp_bytes_offset_from_fa += m_wordsize;
+ // the PUSH instruction has moved the stack pointer - if the FA is set
// in terms of the stack pointer, we need to add a new row of
// instructions.
- if (row->GetCFAValue().GetRegisterNumber() == m_lldb_sp_regnum) {
- row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_sp_regnum) {
+ fa_value_ptr->SetOffset(current_sp_bytes_offset_from_fa);
row_updated = true;
}
// record where non-volatile (callee-saved, spilled) registers are saved
@@ -740,7 +866,10 @@
machine_regno_to_lldb_regno(machine_regno, lldb_regno) &&
saved_registers[machine_regno] == false) {
UnwindPlan::Row::RegisterLocation regloc;
- regloc.SetAtCFAPlusOffset(-current_sp_bytes_offset_from_cfa);
+ if (is_aligned)
+ regloc.SetAtAFAPlusOffset(-current_sp_bytes_offset_from_fa);
+ else
+ regloc.SetAtCFAPlusOffset(-current_sp_bytes_offset_from_fa);
row->SetRegisterInfo(lldb_regno, regloc);
saved_registers[machine_regno] = true;
row_updated = true;
@@ -748,7 +877,7 @@
}
else if (pop_reg_p(machine_regno)) {
- current_sp_bytes_offset_from_cfa -= m_wordsize;
+ current_sp_bytes_offset_from_fa -= m_wordsize;
if (nonvolatile_reg_p(machine_regno) &&
machine_regno_to_lldb_regno(machine_regno, lldb_regno) &&
@@ -756,29 +885,29 @@
saved_registers[machine_regno] = false;
row->RemoveRegisterInfo(lldb_regno);
- if (machine_regno == (int)m_machine_fp_regnum) {
- row->GetCFAValue().SetIsRegisterPlusOffset(
- m_lldb_sp_regnum, row->GetCFAValue().GetOffset());
+ if (lldb_regno == fa_value_ptr->GetRegisterNumber()) {
+ fa_value_ptr->SetIsRegisterPlusOffset(
+ m_lldb_sp_regnum, fa_value_ptr->GetOffset());
}
in_epilogue = true;
row_updated = true;
}
- // the POP instruction has moved the stack pointer - if the CFA is set in
+ // the POP instruction has moved the stack pointer - if the FA is set in
// terms of the stack pointer, we need to add a new row of instructions.
- if (row->GetCFAValue().GetRegisterNumber() == m_lldb_sp_regnum) {
- row->GetCFAValue().SetIsRegisterPlusOffset(
- m_lldb_sp_regnum, current_sp_bytes_offset_from_cfa);
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_sp_regnum) {
+ fa_value_ptr->SetIsRegisterPlusOffset(
+ m_lldb_sp_regnum, current_sp_bytes_offset_from_fa);
row_updated = true;
}
}
else if (pop_misc_reg_p()) {
- current_sp_bytes_offset_from_cfa -= m_wordsize;
- if (row->GetCFAValue().GetRegisterNumber() == m_lldb_sp_regnum) {
- row->GetCFAValue().SetIsRegisterPlusOffset(
- m_lldb_sp_regnum, current_sp_bytes_offset_from_cfa);
+ current_sp_bytes_offset_from_fa -= m_wordsize;
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_sp_regnum) {
+ fa_value_ptr->SetIsRegisterPlusOffset(
+ m_lldb_sp_regnum, current_sp_bytes_offset_from_fa);
row_updated = true;
}
}
@@ -787,24 +916,38 @@
// off the stack into rbp (restoring the caller's rbp value). It is the
// opposite of ENTER, or 'push rbp, mov rsp rbp'.
else if (leave_pattern_p()) {
- // We're going to copy the value in rbp into rsp, so re-set the sp offset
- // based on the CFAValue. Also, adjust it to recognize that we're
- // popping the saved rbp value off the stack.
- current_sp_bytes_offset_from_cfa = row->GetCFAValue().GetOffset();
- current_sp_bytes_offset_from_cfa -= m_wordsize;
- row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+ if (saved_registers[m_machine_fp_regnum]) {
+ saved_registers[m_machine_fp_regnum] = false;
+ row->RemoveRegisterInfo(m_lldb_fp_regnum);
- // rbp is restored to the caller's value
- saved_registers[m_machine_fp_regnum] = false;
- row->RemoveRegisterInfo(m_lldb_fp_regnum);
+ row_updated = true;
+ }
- // cfa is now in terms of rsp again.
- row->GetCFAValue().SetIsRegisterPlusOffset(
- m_lldb_sp_regnum, row->GetCFAValue().GetOffset());
- row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+ if (is_aligned && cfa_value.GetRegisterNumber() == m_lldb_fp_regnum)
+ {
+ is_aligned = false;
+ fa_value_ptr = &cfa_value;
+ afa_value.SetUnspecified();
+ row_updated = true;
+ }
+
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_fp_regnum)
+ {
+ fa_value_ptr->SetIsRegisterPlusOffset(
+ m_lldb_sp_regnum, fa_value_ptr->GetOffset());
+
+ current_sp_bytes_offset_from_fa = fa_value_ptr->GetOffset();
+ }
+
+ current_sp_bytes_offset_from_fa -= m_wordsize;
+
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_sp_regnum) {
+ fa_value_ptr->SetIsRegisterPlusOffset(
+ m_lldb_sp_regnum, current_sp_bytes_offset_from_fa);
+ row_updated = true;
+ }
in_epilogue = true;
- row_updated = true;
}
else if (mov_reg_to_local_stack_frame_p(machine_regno, stack_offset) &&
@@ -816,12 +959,14 @@
UnwindPlan::Row::RegisterLocation regloc;
// stack_offset for 'movq %r15, -80(%rbp)' will be 80. In the Row, we
- // want to express this as the offset from the CFA. If the frame base is
- // rbp (like the above instruction), the CFA offset for rbp is probably
- // 16. So we want to say that the value is stored at the CFA address -
+ // want to express this as the offset from the FA. If the frame base is
+ // rbp (like the above instruction), the FA offset for rbp is probably
+ // 16. So we want to say that the value is stored at the FA address -
// 96.
- regloc.SetAtCFAPlusOffset(
- -(stack_offset + row->GetCFAValue().GetOffset()));
+ if (is_aligned)
+ regloc.SetAtAFAPlusOffset(-(stack_offset + fa_value_ptr->GetOffset()));
+ else
+ regloc.SetAtCFAPlusOffset(-(stack_offset + fa_value_ptr->GetOffset()));
row->SetRegisterInfo(lldb_regno, regloc);
@@ -829,17 +974,17 @@
}
else if (sub_rsp_pattern_p(stack_offset)) {
- current_sp_bytes_offset_from_cfa += stack_offset;
- if (row->GetCFAValue().GetRegisterNumber() == m_lldb_sp_regnum) {
- row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+ current_sp_bytes_offset_from_fa += stack_offset;
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_sp_regnum) {
+ fa_value_ptr->SetOffset(current_sp_bytes_offset_from_fa);
row_updated = true;
}
}
else if (add_rsp_pattern_p(stack_offset)) {
- current_sp_bytes_offset_from_cfa -= stack_offset;
- if (row->GetCFAValue().GetRegisterNumber() == m_lldb_sp_regnum) {
- row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+ current_sp_bytes_offset_from_fa -= stack_offset;
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_sp_regnum) {
+ fa_value_ptr->SetOffset(current_sp_bytes_offset_from_fa);
row_updated = true;
}
in_epilogue = true;
@@ -847,27 +992,48 @@
else if (push_extended_pattern_p() || push_imm_pattern_p() ||
push_misc_reg_p()) {
- current_sp_bytes_offset_from_cfa += m_wordsize;
- if (row->GetCFAValue().GetRegisterNumber() == m_lldb_sp_regnum) {
- row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+ current_sp_bytes_offset_from_fa += m_wordsize;
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_sp_regnum) {
+ fa_value_ptr->SetOffset(current_sp_bytes_offset_from_fa);
row_updated = true;
}
}
else if (lea_rsp_pattern_p(stack_offset)) {
- current_sp_bytes_offset_from_cfa -= stack_offset;
- if (row->GetCFAValue().GetRegisterNumber() == m_lldb_sp_regnum) {
- row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+ current_sp_bytes_offset_from_fa -= stack_offset;
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_sp_regnum) {
+ fa_value_ptr->SetOffset(current_sp_bytes_offset_from_fa);
row_updated = true;
}
if (stack_offset > 0)
in_epilogue = true;
}
- else if (lea_rbp_rsp_pattern_p(stack_offset) &&
- row->GetCFAValue().GetRegisterNumber() == m_lldb_fp_regnum) {
- current_sp_bytes_offset_from_cfa =
- row->GetCFAValue().GetOffset() - stack_offset;
+ else if (lea_rbp_rsp_pattern_p(stack_offset)) {
+ if (is_aligned &&
+ cfa_value.GetRegisterNumber() == m_lldb_fp_regnum) {
+ is_aligned = false;
+ fa_value_ptr = &cfa_value;
+ afa_value.SetUnspecified();
+ row_updated = true;
+ }
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_fp_regnum) {
+ current_sp_bytes_offset_from_fa =
+ fa_value_ptr->GetOffset() - stack_offset;
+ }
+ }
+
+ else if (lea_rbx_rsp_pattern_p(stack_offset)) {
+ if (is_aligned &&
+ cfa_value.GetRegisterNumber() == m_lldb_alt_fp_regnum) {
+ is_aligned = false;
+ fa_value_ptr = &cfa_value;
+ afa_value.SetUnspecified();
+ row_updated = true;
+ }
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_alt_fp_regnum) {
+ current_sp_bytes_offset_from_fa = fa_value_ptr->GetOffset() - stack_offset;
+ }
}
else if (ret_pattern_p() && prologue_completed_row.get()) {
@@ -877,8 +1043,9 @@
UnwindPlan::Row *newrow = new UnwindPlan::Row;
*newrow = *prologue_completed_row.get();
row.reset(newrow);
- current_sp_bytes_offset_from_cfa =
+ current_sp_bytes_offset_from_fa =
prologue_completed_sp_bytes_offset_from_cfa;
+ is_aligned = prologue_completed_is_aligned;
saved_registers.clear();
saved_registers.resize(prologue_completed_saved_registers.size(), false);
@@ -896,9 +1063,9 @@
// This is used in i386 programs to get the PIC base address for finding
// global data
else if (call_next_insn_pattern_p()) {
- current_sp_bytes_offset_from_cfa += m_wordsize;
- if (row->GetCFAValue().GetRegisterNumber() == m_lldb_sp_regnum) {
- row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+ current_sp_bytes_offset_from_fa += m_wordsize;
+ if (fa_value_ptr->GetRegisterNumber() == m_lldb_sp_regnum) {
+ fa_value_ptr->SetOffset(current_sp_bytes_offset_from_fa);
row_updated = true;
}
}
@@ -931,7 +1098,8 @@
// track of it either way.
if (in_epilogue == false) {
prologue_completed_sp_bytes_offset_from_cfa =
- current_sp_bytes_offset_from_cfa;
+ current_sp_bytes_offset_from_fa;
+ prologue_completed_is_aligned = is_aligned;
}
m_cur_insn = m_cur_insn + insn_len;
diff --git a/lldb/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.h b/lldb/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.h
index cec9803..e02b510 100644
--- a/lldb/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.h
+++ b/lldb/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.h
@@ -98,10 +98,15 @@
bool push_extended_pattern_p();
bool push_misc_reg_p();
bool mov_rsp_rbp_pattern_p();
+ bool mov_rsp_rbx_pattern_p();
+ bool mov_rbp_rsp_pattern_p();
+ bool mov_rbx_rsp_pattern_p();
bool sub_rsp_pattern_p(int &amount);
bool add_rsp_pattern_p(int &amount);
bool lea_rsp_pattern_p(int &amount);
bool lea_rbp_rsp_pattern_p(int &amount);
+ bool lea_rbx_rsp_pattern_p(int &amount);
+ bool and_rsp_pattern_p();
bool push_reg_p(int ®no);
bool pop_reg_p(int ®no);
bool pop_rbp_pattern_p();
@@ -157,9 +162,11 @@
uint32_t m_machine_ip_regnum;
uint32_t m_machine_sp_regnum;
uint32_t m_machine_fp_regnum;
+ uint32_t m_machine_alt_fp_regnum;
uint32_t m_lldb_ip_regnum;
uint32_t m_lldb_sp_regnum;
uint32_t m_lldb_fp_regnum;
+ uint32_t m_lldb_alt_fp_regnum;
typedef std::map<uint32_t, lldb_reg_info> MachineRegnumToNameAndLLDBRegnum;