werat created this revision.
werat added reviewers: labath, jingham, jasonmolenda.
Herald added a project: All.
werat requested review of this revision.
Herald added a project: LLDB.
Herald added a subscriber: lldb-commits.
DW_OP_skip/DW_OP_bra can move offset to the end of the data, which means that
this was the last instruction to execute and the interpreter should terminate.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D130285
Files:
lldb/source/Expression/DWARFExpression.cpp
lldb/unittests/Expression/DWARFExpressionTest.cpp
Index: lldb/unittests/Expression/DWARFExpressionTest.cpp
===================================================================
--- lldb/unittests/Expression/DWARFExpressionTest.cpp
+++ lldb/unittests/Expression/DWARFExpressionTest.cpp
@@ -131,6 +131,25 @@
llvm::HasValue(0xffff010101010101));
}
+TEST(DWARFExpression, DW_OP_skip) {
+ EXPECT_THAT_EXPECTED(Evaluate({DW_OP_const1u, 0x42, DW_OP_skip, 0x02, 0x00,
+ DW_OP_const1u, 0xff}),
+ llvm::HasValue(0x42));
+}
+
+TEST(DWARFExpression, DW_OP_bra) {
+ EXPECT_THAT_EXPECTED(
+ // clang-format off
+ Evaluate({
+ DW_OP_const1u, 0x42, // push 0x42
+ DW_OP_const1u, 0x1, // push 0x1
+ DW_OP_bra, 0x02, 0x00, // if 0x1 > 0, then skip 0x0002 opcodes
+ DW_OP_const1u, 0xff, // push 0xff
+ }),
+ // clang-format on
+ llvm::HasValue(0x42));
+}
+
TEST(DWARFExpression, DW_OP_convert) {
/// Auxiliary debug info.
const char *yamldata = R"(
Index: lldb/source/Expression/DWARFExpression.cpp
===================================================================
--- lldb/source/Expression/DWARFExpression.cpp
+++ lldb/source/Expression/DWARFExpression.cpp
@@ -1655,11 +1655,16 @@
case DW_OP_skip: {
int16_t skip_offset = (int16_t)opcodes.GetU16(&offset);
lldb::offset_t new_offset = offset + skip_offset;
- if (opcodes.ValidOffset(new_offset))
+ // New offset can point at the end of the data, in this case we should
+ // terminate the DWARF expression evaluation (will happen in the loop
+ // condition).
+ if (new_offset <= opcodes.GetByteSize())
offset = new_offset;
else {
if (error_ptr)
- error_ptr->SetErrorString("Invalid opcode offset in DW_OP_skip.");
+ error_ptr->SetErrorStringWithFormatv(
+ "Invalid opcode offset in DW_OP_skip: {0}+({1}) > {2}", offset,
+ skip_offset, opcodes.GetByteSize());
return false;
}
} break;
@@ -1684,11 +1689,16 @@
Scalar zero(0);
if (tmp.ResolveValue(exe_ctx) != zero) {
lldb::offset_t new_offset = offset + bra_offset;
- if (opcodes.ValidOffset(new_offset))
+ // New offset can point at the end of the data, in this case we
should
+ // terminate the DWARF expression evaluation (will happen in the loop
+ // condition).
+ if (new_offset <= opcodes.GetByteSize())
offset = new_offset;
else {
if (error_ptr)
- error_ptr->SetErrorString("Invalid opcode offset in DW_OP_bra.");
+ error_ptr->SetErrorStringWithFormatv(
+ "Invalid opcode offset in DW_OP_bra: {0}+({1}) > {2}",
offset,
+ bra_offset, opcodes.GetByteSize());
return false;
}
}
Index: lldb/unittests/Expression/DWARFExpressionTest.cpp
===================================================================
--- lldb/unittests/Expression/DWARFExpressionTest.cpp
+++ lldb/unittests/Expression/DWARFExpressionTest.cpp
@@ -131,6 +131,25 @@
llvm::HasValue(0xffff010101010101));
}
+TEST(DWARFExpression, DW_OP_skip) {
+ EXPECT_THAT_EXPECTED(Evaluate({DW_OP_const1u, 0x42, DW_OP_skip, 0x02, 0x00,
+ DW_OP_const1u, 0xff}),
+ llvm::HasValue(0x42));
+}
+
+TEST(DWARFExpression, DW_OP_bra) {
+ EXPECT_THAT_EXPECTED(
+ // clang-format off
+ Evaluate({
+ DW_OP_const1u, 0x42, // push 0x42
+ DW_OP_const1u, 0x1, // push 0x1
+ DW_OP_bra, 0x02, 0x00, // if 0x1 > 0, then skip 0x0002 opcodes
+ DW_OP_const1u, 0xff, // push 0xff
+ }),
+ // clang-format on
+ llvm::HasValue(0x42));
+}
+
TEST(DWARFExpression, DW_OP_convert) {
/// Auxiliary debug info.
const char *yamldata = R"(
Index: lldb/source/Expression/DWARFExpression.cpp
===================================================================
--- lldb/source/Expression/DWARFExpression.cpp
+++ lldb/source/Expression/DWARFExpression.cpp
@@ -1655,11 +1655,16 @@
case DW_OP_skip: {
int16_t skip_offset = (int16_t)opcodes.GetU16(&offset);
lldb::offset_t new_offset = offset + skip_offset;
- if (opcodes.ValidOffset(new_offset))
+ // New offset can point at the end of the data, in this case we should
+ // terminate the DWARF expression evaluation (will happen in the loop
+ // condition).
+ if (new_offset <= opcodes.GetByteSize())
offset = new_offset;
else {
if (error_ptr)
- error_ptr->SetErrorString("Invalid opcode offset in DW_OP_skip.");
+ error_ptr->SetErrorStringWithFormatv(
+ "Invalid opcode offset in DW_OP_skip: {0}+({1}) > {2}", offset,
+ skip_offset, opcodes.GetByteSize());
return false;
}
} break;
@@ -1684,11 +1689,16 @@
Scalar zero(0);
if (tmp.ResolveValue(exe_ctx) != zero) {
lldb::offset_t new_offset = offset + bra_offset;
- if (opcodes.ValidOffset(new_offset))
+ // New offset can point at the end of the data, in this case we should
+ // terminate the DWARF expression evaluation (will happen in the loop
+ // condition).
+ if (new_offset <= opcodes.GetByteSize())
offset = new_offset;
else {
if (error_ptr)
- error_ptr->SetErrorString("Invalid opcode offset in DW_OP_bra.");
+ error_ptr->SetErrorStringWithFormatv(
+ "Invalid opcode offset in DW_OP_bra: {0}+({1}) > {2}", offset,
+ bra_offset, opcodes.GetByteSize());
return false;
}
}
_______________________________________________
lldb-commits mailing list
lldb-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
