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-rw-r--r--lib/ubsan/lit_tests/TypeCheck/vptr.cpp8
-rw-r--r--lib/ubsan/ubsan_diag.cc25
-rw-r--r--lib/ubsan/ubsan_diag.h11
-rw-r--r--lib/ubsan/ubsan_handlers_cxx.cc11
-rw-r--r--lib/ubsan/ubsan_type_hash.cc43
-rw-r--r--lib/ubsan/ubsan_type_hash.h7
6 files changed, 91 insertions, 14 deletions
diff --git a/lib/ubsan/lit_tests/TypeCheck/vptr.cpp b/lib/ubsan/lit_tests/TypeCheck/vptr.cpp
index a4f97baed..574a7bef9 100644
--- a/lib/ubsan/lit_tests/TypeCheck/vptr.cpp
+++ b/lib/ubsan/lit_tests/TypeCheck/vptr.cpp
@@ -75,7 +75,7 @@ int main(int, char **argv) {
case 'm':
// CHECK-MEMBER: vptr.cpp:[[@LINE+5]]:15: runtime error: member access within address [[PTR:0x[0-9a-f]*]] which does not point to an object of type 'T'
- // CHECK-MEMBER-NEXT: [[PTR]]: note: object is of type [[DYN_TYPE:1S|1U]]
+ // CHECK-MEMBER-NEXT: [[PTR]]: note: object is of type [[DYN_TYPE:'S'|'U']]
// CHECK-MEMBER-NEXT: {{^ .. .. .. .. .. .. .. .. .. .. .. .. }}
// CHECK-MEMBER-NEXT: {{^ \^~~~~~~~~~~(~~~~~~~~~~~~)? *$}}
// CHECK-MEMBER-NEXT: {{^ vptr for}} [[DYN_TYPE]]
@@ -89,7 +89,7 @@ int main(int, char **argv) {
case 'f':
// CHECK-MEMFUN: vptr.cpp:[[@LINE+5]]:12: runtime error: member call on address [[PTR:0x[0-9a-f]*]] which does not point to an object of type 'T'
- // CHECK-MEMFUN-NEXT: [[PTR]]: note: object is of type [[DYN_TYPE:1S|1U]]
+ // CHECK-MEMFUN-NEXT: [[PTR]]: note: object is of type [[DYN_TYPE:'S'|'U']]
// CHECK-MEMFUN-NEXT: {{^ .. .. .. .. .. .. .. .. .. .. .. .. }}
// CHECK-MEMFUN-NEXT: {{^ \^~~~~~~~~~~(~~~~~~~~~~~~)? *$}}
// CHECK-MEMFUN-NEXT: {{^ vptr for}} [[DYN_TYPE]]
@@ -97,10 +97,10 @@ int main(int, char **argv) {
case 'o':
// CHECK-OFFSET: vptr.cpp:[[@LINE+5]]:12: runtime error: member call on address [[PTR:0x[0-9a-f]*]] which does not point to an object of type 'U'
- // CHECK-OFFSET-NEXT: 0x{{[0-9a-f]*}}: note: object is base class subobject at offset {{8|16}} within object of type [[DYN_TYPE:1U]]
+ // CHECK-OFFSET-NEXT: 0x{{[0-9a-f]*}}: note: object is base class subobject at offset {{8|16}} within object of type [[DYN_TYPE:'U']]
// CHECK-OFFSET-NEXT: {{^ .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. }}
// CHECK-OFFSET-NEXT: {{^ \^ ( ~~~~~~~~~~~~)~~~~~~~~~~~ *$}}
- // CHECK-OFFSET-NEXT: {{^ ( )?vptr for}} [[DYN_TYPE]]
+ // CHECK-OFFSET-NEXT: {{^ ( )?vptr for}} 'T' base class of [[DYN_TYPE]]
return reinterpret_cast<U*>(p)->v() - 2;
}
}
diff --git a/lib/ubsan/ubsan_diag.cc b/lib/ubsan/ubsan_diag.cc
index 38dfc8512..517ce6b68 100644
--- a/lib/ubsan/ubsan_diag.cc
+++ b/lib/ubsan/ubsan_diag.cc
@@ -54,7 +54,7 @@ Diag &Diag::operator<<(const Value &V) {
return *this;
}
-/// Hexadecimal printing for numbers too large for fprintf to handle directly.
+/// Hexadecimal printing for numbers too large for Printf to handle directly.
static void PrintHex(UIntMax Val) {
#if HAVE_INT128_T
Printf("0x%08x%08x%08x%08x",
@@ -93,6 +93,15 @@ static void renderLocation(Location Loc) {
}
}
+// C++ demangling function, as required by Itanium C++ ABI. This is weak,
+// because we do not require a C++ ABI library to be linked to a program
+// using UBSan; if it's not present, we'll just print the string mangled.
+namespace __cxxabiv1 {
+ extern "C" char *__cxa_demangle(const char *mangled, char *buffer,
+ size_t *length, int *status)
+ __attribute__((weak));
+}
+
static void renderText(const char *Message, const Diag::Arg *Args) {
for (const char *Msg = Message; *Msg; ++Msg) {
if (*Msg != '%') {
@@ -109,6 +118,20 @@ static void renderText(const char *Message, const Diag::Arg *Args) {
case Diag::AK_String:
Printf("%s", A.String);
break;
+ case Diag::AK_Mangled: {
+ const char *String = 0;
+ // FIXME: __cxa_demangle aggressively insists on allocating memory.
+ // There's not much we can do about that, short of providing our
+ // own demangler (libc++abi's implementation could easily be made
+ // to not allocate). For now, we just call it anyway, and we leak
+ // the returned value.
+ if (__cxxabiv1::__cxa_demangle)
+ String = __cxxabiv1::__cxa_demangle(A.String, 0, 0, 0);
+ RawWrite("'");
+ RawWrite(String ? String : A.String);
+ RawWrite("'");
+ break;
+ }
case Diag::AK_SInt:
// 'long long' is guaranteed to be at least 64 bits wide.
if (A.SInt >= INT64_MIN && A.SInt <= INT64_MAX)
diff --git a/lib/ubsan/ubsan_diag.h b/lib/ubsan/ubsan_diag.h
index a77c71b66..16afffdb0 100644
--- a/lib/ubsan/ubsan_diag.h
+++ b/lib/ubsan/ubsan_diag.h
@@ -100,6 +100,14 @@ public:
const char *getText() const { return Text; }
};
+/// \brief A mangled C++ name. Really just a strong typedef for 'const char*'.
+class MangledName {
+ const char *Name;
+public:
+ MangledName(const char *Name) : Name(Name) {}
+ const char *getName() const { return Name; }
+};
+
/// \brief Representation of an in-flight diagnostic.
///
/// Temporary \c Diag instances are created by the handler routines to
@@ -120,6 +128,7 @@ public:
/// Kinds of arguments, corresponding to members of \c Arg's union.
enum ArgKind {
AK_String, ///< A string argument, displayed as-is.
+ AK_Mangled,///< A C++ mangled name, demangled before display.
AK_UInt, ///< An unsigned integer argument.
AK_SInt, ///< A signed integer argument.
AK_Float, ///< A floating-point argument.
@@ -130,6 +139,7 @@ public:
struct Arg {
Arg() {}
Arg(const char *String) : Kind(AK_String), String(String) {}
+ Arg(MangledName MN) : Kind(AK_Mangled), String(MN.getName()) {}
Arg(UIntMax UInt) : Kind(AK_UInt), UInt(UInt) {}
Arg(SIntMax SInt) : Kind(AK_SInt), SInt(SInt) {}
Arg(FloatMax Float) : Kind(AK_Float), Float(Float) {}
@@ -179,6 +189,7 @@ public:
~Diag();
Diag &operator<<(const char *Str) { return AddArg(Str); }
+ Diag &operator<<(MangledName MN) { return AddArg(MN); }
Diag &operator<<(unsigned long long V) { return AddArg(UIntMax(V)); }
Diag &operator<<(const void *V) { return AddArg(V); }
Diag &operator<<(const TypeDescriptor &V);
diff --git a/lib/ubsan/ubsan_handlers_cxx.cc b/lib/ubsan/ubsan_handlers_cxx.cc
index e3f39cca5..b199dc7d5 100644
--- a/lib/ubsan/ubsan_handlers_cxx.cc
+++ b/lib/ubsan/ubsan_handlers_cxx.cc
@@ -42,17 +42,20 @@ static void HandleDynamicTypeCacheMiss(
DynamicTypeInfo DTI = getDynamicTypeInfo((void*)Pointer);
if (!DTI.isValid())
Diag(Pointer, DL_Note, "object has invalid vptr")
- << DTI.getMostDerivedTypeName()
+ << MangledName(DTI.getMostDerivedTypeName())
<< Range(Pointer, Pointer + sizeof(uptr), "invalid vptr");
else if (!DTI.getOffset())
Diag(Pointer, DL_Note, "object is of type %0")
- << DTI.getMostDerivedTypeName()
+ << MangledName(DTI.getMostDerivedTypeName())
<< Range(Pointer, Pointer + sizeof(uptr), "vptr for %0");
else
+ // FIXME: Find the type at the specified offset, and include that
+ // in the note.
Diag(Pointer - DTI.getOffset(), DL_Note,
"object is base class subobject at offset %0 within object of type %1")
- << DTI.getOffset() << DTI.getMostDerivedTypeName()
- << Range(Pointer, Pointer + sizeof(uptr), "vptr for %1");
+ << DTI.getOffset() << MangledName(DTI.getMostDerivedTypeName())
+ << MangledName(DTI.getSubobjectTypeName())
+ << Range(Pointer, Pointer + sizeof(uptr), "vptr for %2 base class of %1");
if (Abort)
Die();
diff --git a/lib/ubsan/ubsan_type_hash.cc b/lib/ubsan/ubsan_type_hash.cc
index ee17af7d8..7a9cd28f6 100644
--- a/lib/ubsan/ubsan_type_hash.cc
+++ b/lib/ubsan/ubsan_type_hash.cc
@@ -129,7 +129,7 @@ static bool isDerivedFromAtOffset(const abi::__class_type_info *Derived,
// No base class subobjects.
return false;
- // Look for a zero-offset base class which is derived from \p Base.
+ // Look for a base class which is derived from \p Base at the right offset.
for (unsigned int base = 0; base != VTI->base_count; ++base) {
// FIXME: Curtail the recursion if this base can't possibly contain the
// given offset.
@@ -149,6 +149,39 @@ static bool isDerivedFromAtOffset(const abi::__class_type_info *Derived,
return false;
}
+/// \brief Find the derived-most dynamic base class of \p Derived at offset
+/// \p Offset.
+static const abi::__class_type_info *findBaseAtOffset(
+ const abi::__class_type_info *Derived, sptr Offset) {
+ if (!Offset)
+ return Derived;
+
+ if (const abi::__si_class_type_info *SI =
+ dynamic_cast<const abi::__si_class_type_info*>(Derived))
+ return findBaseAtOffset(SI->__base_type, Offset);
+
+ const abi::__vmi_class_type_info *VTI =
+ dynamic_cast<const abi::__vmi_class_type_info*>(Derived);
+ if (!VTI)
+ // No base class subobjects.
+ return 0;
+
+ for (unsigned int base = 0; base != VTI->base_count; ++base) {
+ sptr OffsetHere = VTI->base_info[base].__offset_flags >>
+ abi::__base_class_type_info::__offset_shift;
+ if (VTI->base_info[base].__offset_flags &
+ abi::__base_class_type_info::__virtual_mask)
+ // FIXME: Can't handle virtual bases yet.
+ continue;
+ if (const abi::__class_type_info *Base =
+ findBaseAtOffset(VTI->base_info[base].__base_type,
+ Offset - OffsetHere))
+ return Base;
+ }
+
+ return 0;
+}
+
namespace {
struct VtablePrefix {
@@ -206,6 +239,10 @@ bool __ubsan::checkDynamicType(void *Object, void *Type, HashValue Hash) {
__ubsan::DynamicTypeInfo __ubsan::getDynamicTypeInfo(void *Object) {
VtablePrefix *Vtable = getVtablePrefix(Object);
if (!Vtable)
- return DynamicTypeInfo(0, 0);
- return DynamicTypeInfo(Vtable->TypeInfo->__type_name, -Vtable->Offset);
+ return DynamicTypeInfo(0, 0, 0);
+ const abi::__class_type_info *ObjectType = findBaseAtOffset(
+ static_cast<const abi::__class_type_info*>(Vtable->TypeInfo),
+ -Vtable->Offset);
+ return DynamicTypeInfo(Vtable->TypeInfo->__type_name, -Vtable->Offset,
+ ObjectType ? ObjectType->__type_name : "<unknown>");
}
diff --git a/lib/ubsan/ubsan_type_hash.h b/lib/ubsan/ubsan_type_hash.h
index dfaf32752..1c5355701 100644
--- a/lib/ubsan/ubsan_type_hash.h
+++ b/lib/ubsan/ubsan_type_hash.h
@@ -24,10 +24,11 @@ typedef uptr HashValue;
class DynamicTypeInfo {
const char *MostDerivedTypeName;
sptr Offset;
+ const char *SubobjectTypeName;
public:
- DynamicTypeInfo(const char *MDTN, sptr Offset)
- : MostDerivedTypeName(MDTN), Offset(Offset) {}
+ DynamicTypeInfo(const char *MDTN, sptr Offset, const char *STN)
+ : MostDerivedTypeName(MDTN), Offset(Offset), SubobjectTypeName(STN) {}
/// Determine whether the object had a valid dynamic type.
bool isValid() const { return MostDerivedTypeName; }
@@ -35,6 +36,8 @@ public:
const char *getMostDerivedTypeName() const { return MostDerivedTypeName; }
/// Get the offset from the most-derived type to this base class.
sptr getOffset() const { return Offset; }
+ /// Get the name of the most-derived type at the specified offset.
+ const char *getSubobjectTypeName() const { return SubobjectTypeName; }
};
/// \brief Get information about the dynamic type of an object.
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-19 18:03:55 +0000