[lldb] Disallow left shifts of negative values in the interpreter #119620
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This trips UBSAN and probably isn't partiuclarly useful either.
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@llvm/pr-subscribers-lldb Author: Adrian Prantl (adrian-prantl) ChangesThis trips UBSAN and probably isn't partiuclarly useful either. Full diff: https://github.com/llvm/llvm-project/pull/119620.diff 2 Files Affected:
diff --git a/lldb/source/DataFormatters/FormatterBytecode.cpp b/lldb/source/DataFormatters/FormatterBytecode.cpp
index f344fbaff6f02a..e49c7506781875 100644
--- a/lldb/source/DataFormatters/FormatterBytecode.cpp
+++ b/lldb/source/DataFormatters/FormatterBytecode.cpp
@@ -379,7 +379,7 @@ llvm::Error Interpret(std::vector<ControlStackElement> &control,
BINOP_CHECKZERO(%);
continue;
case op_shl:
-#define SHIFTOP(OP) \
+#define SHIFTOP(OP, LEFT) \
{ \
TYPE_CHECK(Any, UInt); \
uint64_t y = data.Pop<uint64_t>(); \
@@ -390,16 +390,18 @@ llvm::Error Interpret(std::vector<ControlStackElement> &control,
data.Push(x OP y); \
} else if (std::holds_alternative<int64_t>(data.back())) { \
int64_t x = data.Pop<int64_t>(); \
+ if (x < 0 && LEFT) \
+ return error("left shift of negative value"); \
if (y > 64) \
return error("shift out of bounds"); \
data.Push(x OP y); \
} else \
return error("unsupported data types"); \
}
- SHIFTOP(<<);
+ SHIFTOP(<<, true);
continue;
case op_shr:
- SHIFTOP(<<);
+ SHIFTOP(>>, false);
continue;
case op_and:
BINOP(&);
diff --git a/lldb/unittests/DataFormatter/FormatterBytecodeTest.cpp b/lldb/unittests/DataFormatter/FormatterBytecodeTest.cpp
index 15d9229de00332..7307db650c1629 100644
--- a/lldb/unittests/DataFormatter/FormatterBytecodeTest.cpp
+++ b/lldb/unittests/DataFormatter/FormatterBytecodeTest.cpp
@@ -147,9 +147,12 @@ TEST_F(FormatterBytecodeTest, ArithOps) {
{
DataStack data;
unsigned char minus_one = 127;
- ASSERT_TRUE(
+ ASSERT_FALSE(
Interpret({op_lit_int, minus_one, op_lit_uint, 2, op_shl}, data));
- ASSERT_EQ(data.Pop<int64_t>(), -4);
+ unsigned char minus_two = 126;
+ ASSERT_TRUE(
+ Interpret({op_lit_int, minus_two, op_lit_uint, 1, op_shr}, data));
+ ASSERT_EQ(data.Pop<int64_t>(), -1);
}
{
DataStack data;
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JDevlieghere
approved these changes
Dec 11, 2024
adrian-prantl
added a commit
to adrian-prantl/llvm-project
that referenced
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Dec 13, 2024
…vm#119620) This trips UBSAN and probably isn't partiuclarly useful either. (cherry picked from commit 2470cfa)
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This trips UBSAN and probably isn't partiuclarly useful either.