JakeHillion/object-introspection
1
0
Fork 0
mirror of https://github.com/JakeHillion/object-introspection.git synced 2024-11-12 21:56:54 +00:00
Code Issues Packages Projects Releases Wiki Activity

remove treebuilder pointer validation

Browse Source
This commit is contained in:
Jake Hillion 2023-04-05 12:55:40 -07:00 committed by Jake Hillion
parent 28025fa416
commit cd2fa8c9ef
10 changed files with 71 additions and 54 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
src/OICodeGen.cpp
View File

@ -3284,7 +3284,10 @@ bool OICodeGen::generateJitCode(std::string& code) {
JLOGPTR(s_ptr);
StoreData((uintptr_t)(s_ptr), returnArg);
if (s_ptr && pointers.add((uintptr_t)s_ptr)) {
getSizeType(*(s_ptr), returnArg);
StoreData(1, returnArg);
getSizeType(*(s_ptr), returnArg);
} else {
StoreData(0, returnArg);
}
}

63
src/TreeBuilder.cpp
View File

@ -39,6 +39,17 @@ extern "C" {
#include <sys/types.h>
}
/* Tag indicating if the pointer has been followed or skipped */
enum class TrackPointerTag: uint64_t {
/* The content has been skipped.
* It prevents double counting the footprint of a node the JIT code has seen
* before, double counting content being stored inline, or getting stuck in an
* infinite loop when processing circular linked list.
*/
skipped = 0,
followed = 1,
};
TreeBuilder::TreeBuilder(Config c) : config{std::move(c)} {
buffer = std::make_unique<msgpack::sbuffer>();
@ -205,7 +216,6 @@ void TreeBuilder::build(const std::vector<uint64_t>& data,
th = &typeHierarchy;
oidData = &data;
pointers.clear();
oidDataIndex = 3; // HACK: OID's first 3 outputs are dummy 0s
ObjectIntrospection::Metrics::Tracing _("build_tree");
@ -215,8 +225,9 @@ void TreeBuilder::build(const std::vector<uint64_t>& data,
auto& rootID = rootIDs.emplace_back(nextNodeID++);
try {
// The first value is the address of the root object
pointers.insert(next());
// The first value is the address of the root object. Drop it as we don't
// need to manage pointer deduplication anymore.
next();
process(rootID, {.type = type, .name = argName, .typePath = argName});
} catch (...) {
// Mark the failure using the error node ID
@ -367,15 +378,6 @@ bool TreeBuilder::isPrimitive(struct drgn_type* type) {
return drgn_type_primitive(type) != DRGN_NOT_PRIMITIVE_TYPE;
}
bool TreeBuilder::shouldProcess(uintptr_t pointer) {
if (pointer == 0U) {
return false;
}
auto [_, unprocessed] = pointers.emplace(pointer);
return unprocessed;
}
static std::string_view drgnKindStr(struct drgn_type* type) {
auto kind = OICodeGen::drgnKindStr(type);
// -1 is for the null terminator
@ -427,8 +429,10 @@ TreeBuilder::Node TreeBuilder::process(NodeID id, Variable variable) {
auto innerTypeKind = drgn_type_kind(entry->second);
if (innerTypeKind != DRGN_TYPE_FUNCTION) {
node.pointer = next();
if (innerTypeKind == DRGN_TYPE_VOID ||
!shouldProcess(*node.pointer)) {
if (innerTypeKind == DRGN_TYPE_VOID) {
break;
}
if (next() == (uint64_t)TrackPointerTag::skipped) {
break;
}
}
@ -626,7 +630,7 @@ void TreeBuilder::processContainer(const Variable& variable, Node& node) {
node.pointer = next();
containerStats.length = *node.pointer ? 1 : 0;
containerStats.capacity = 1;
if (!shouldProcess(*node.pointer)) {
if (next() == (uint64_t)TrackPointerTag::skipped) {
return;
}
break;
@ -634,7 +638,7 @@ void TreeBuilder::processContainer(const Variable& variable, Node& node) {
case REF_WRAPPER_TYPE:
node.pointer = next();
containerStats.length = containerStats.capacity = 1;
if (!shouldProcess(*node.pointer)) {
if (next() == (uint64_t)TrackPointerTag::skipped) {
return;
}
break;
@ -723,7 +727,7 @@ void TreeBuilder::processContainer(const Variable& variable, Node& node) {
case FOLLY_IOBUFQUEUE_TYPE:
node.pointer = next();
containerStats.length = containerStats.capacity = 0;
if (!shouldProcess(*node.pointer)) {
if (next() == (uint64_t)TrackPointerTag::skipped) {
return;
}
// Fallthrough to the IOBuf data if we have a valid pointer
@ -736,20 +740,17 @@ void TreeBuilder::processContainer(const Variable& variable, Node& node) {
node.pointer = next();
containerStats.capacity = next();
containerStats.length = next();
// If this string's data is potentially shared (cutoff for sharing is 255)
if (containerStats.capacity >= 255) {
// Contents aren't actually stored inline in this case,
// but we set this to `true` so that we don't double-count
// this string's data if we have seen it before.
contentsStoredInline = !shouldProcess(*node.pointer);
} else {
// No sense in recording the pointer value if the string isn't
// potentially shared
node.pointer.reset();
// Account for Small String Optimization (SSO)
const int fbStringSsoCutOff = 23;
constexpr size_t ssoCutoff = fbStringSsoCutOff;
contentsStoredInline = containerStats.capacity <= ssoCutoff;
// Contents are either stored inline or have been seen before in the JIT
// code. Set to true either way so as not to double count.
contentsStoredInline = next() == 0;
{
constexpr int sharedCutOff = 255;
if (containerStats.capacity < sharedCutOff) {
// No sense in recording the pointer value if the string isn't
// potentially shared.
node.pointer.reset();
}
}
break;
case STRING_TYPE:

2
src/TreeBuilder.h
View File

@ -99,13 +99,11 @@ class TreeBuilder {
*/
std::unique_ptr<msgpack::sbuffer> buffer;
rocksdb::DB* db = nullptr;
std::unordered_set<uintptr_t> pointers{};
uint64_t getDrgnTypeSize(struct drgn_type* type);
uint64_t next();
bool isContainer(const Variable& variable);
bool isPrimitive(struct drgn_type* type);
bool shouldProcess(uintptr_t pointer);
Node process(NodeID id, Variable variable);
void processContainer(const Variable& variable, Node& node);
template <class T>

2
test/integration/cycles.toml
View File

@ -90,7 +90,6 @@ definitions = '''
'''
[cases.unique_ptr]
oil_skip = "OIL processes one node in the cycle twice" # https://github.com/facebookexperimental/object-introspection/issues/104
param_types = ["std::reference_wrapper<UniqueNode>&"]
setup = '''
auto first = std::make_unique<UniqueNode>();
@ -168,7 +167,6 @@ definitions = '''
'''
[cases.shared_ptr]
oil_skip = "OIL processes one node in the cycle twice" # https://github.com/facebookexperimental/object-introspection/issues/104
param_types = ["std::reference_wrapper<SharedNode>&"]
setup = '''
auto first = std::make_shared<SharedNode>();

1
test/integration/fbstring.toml
View File

@ -76,7 +76,6 @@ includes = ["folly/FBString.h"]
'''
[cases.string_pooled]
skip = "Potentially incorrect dynamic size"
param_types = ["folly::fbstring&"]
setup = "return folly::fbstring(1024, 'c');"
expect_json = '''

15
types/fb_string_type.toml
View File

@ -24,12 +24,15 @@ void getSizeType(const %1%<E, T, A, Storage> &t, size_t& returnArg)
SAVE_DATA((uintptr_t)t.capacity());
SAVE_DATA((uintptr_t)t.size());
// Check if the string is contained within the type (inlined) so as not to double count.
SAVE_SIZE(
((uintptr_t)t.data() < (uintptr_t)(&t + sizeof(%1%<E, T, A, Storage>)))
bool inlined = ((uintptr_t)t.data() < (uintptr_t)(&t + sizeof(%1%<E, T, A, Storage>)))
&&
((uintptr_t)t.data() >= (uintptr_t)&t)
? 0 : (t.capacity() * sizeof(T))
);
((uintptr_t)t.data() >= (uintptr_t)&t);
if (!inlined && pointers.add((uintptr_t)t.data())) {
SAVE_SIZE(t.capacity() * sizeof(T));
SAVE_DATA(1);
} else {
SAVE_DATA(0);
}
}
"""

8
types/folly_iobuf_queue_type.toml
View File

@ -21,7 +21,11 @@ void getSizeType(const %1% &t, size_t& returnArg)
const IOBuf *head = t.front();
SAVE_DATA((uintptr_t)head);
if (head)
getSizeType(*head, returnArg);
if (head && pointers.add((uintptr_t)head)) {
SAVE_DATA(1);
getSizeType(*head, returnArg);
} else {
SAVE_DATA(0);
}
}
"""

7
types/ref_wrapper_type.toml
View File

@ -20,6 +20,11 @@ void getSizeType(const %1%<T> &ref, size_t& returnArg)
{
SAVE_SIZE(sizeof(%1%<T>));
SAVE_DATA((uintptr_t)&(ref.get()));
getSizeType(ref.get(), returnArg);
if (pointers.add((uintptr_t)&ref.get())) {
SAVE_DATA(1);
getSizeType(ref.get(), returnArg);
} else {
SAVE_DATA(0);
}
}
"""

11
types/shrd_ptr_type.toml
View File

@ -21,11 +21,14 @@ void getSizeType(const %1%<T> &s_ptr, size_t& returnArg)
SAVE_SIZE(sizeof(%1%<T>));
if constexpr (!std::is_void<T>::value) {
SAVE_DATA((uintptr_t)(s_ptr.get()));
SAVE_DATA((uintptr_t)(s_ptr.get()));
if (s_ptr && pointers.add((uintptr_t)(s_ptr.get()))) {
getSizeType(*(s_ptr.get()), returnArg);
}
if (s_ptr && pointers.add((uintptr_t)(s_ptr.get()))) {
SAVE_DATA(1);
getSizeType(*(s_ptr.get()), returnArg);
} else {
SAVE_DATA(0);
}
}
}
"""

11
types/uniq_ptr_type.toml
View File

@ -21,11 +21,14 @@ void getSizeType(const %1%<T,Deleter> &s_ptr, size_t& returnArg)
SAVE_SIZE(sizeof(%1%<T,Deleter>));
if constexpr (!std::is_void<T>::value) {
SAVE_DATA((uintptr_t)(s_ptr.get()));
SAVE_DATA((uintptr_t)(s_ptr.get()));
if (s_ptr && pointers.add((uintptr_t)(s_ptr.get()))) {
getSizeType(*(s_ptr.get()), returnArg);
}
if (s_ptr && pointers.add((uintptr_t)(s_ptr.get()))) {
SAVE_DATA(1);
getSizeType(*(s_ptr.get()), returnArg);
} else {
SAVE_DATA(0);
}
}
}
"""