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feat: recognize ownsem instrinsic aliases
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@priyasiddharth
priyasiddharth committed Jun 13, 2024
1 parent 8fc33bd commit 93edd5d
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Showing 3 changed files with 65 additions and 26 deletions.
15 changes: 15 additions & 0 deletions include/seadsa/ownsem.h
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Original file line number Diff line number Diff line change
@@ -0,0 +1,15 @@
#ifndef OWNSEM_H_
#define OWNSEM_H_

#include <boost/hana.hpp>

constexpr auto OWNSEM_BUILTIN_NAMES = boost::hana::make_set(
"sea.mkown", "sea.mkshr", "sea.bor_mkbor", "sea.bor_ptr", "sea.bor_mksuc",
"sea.begin_unique", "sea.end_unique",
// "sea.die", // This is not a ptr def operation
"sea.mov",
// Builtin for fat ptr (slot0 and slot1 only)
"sea.set_fatptr_slot", "sea.get_fatptr_slot", "sea.bor_mem2reg",
"sea.mov_mem2reg", "sea.bor_mkbor_part");

#endif // OWNSEM_H_
4 changes: 2 additions & 2 deletions include/seadsa/sea_dsa.h
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Original file line number Diff line number Diff line change
Expand Up @@ -26,10 +26,10 @@ extern void sea_dsa_set_external(const void *p);
// sea-dsa will collapse the argument's cell
extern void sea_dsa_collapse(const void *p);
// sea-dsa will return a fresh memory object
extern void *sea_dsa_new() __attribute__((malloc));
extern void *sea_dsa_new(void) __attribute__((malloc));
// like sea_dsa_new except used for creating a node representation of an
// existing memory object
extern void *sea_dsa_mk();
extern void *sea_dsa_mk(void);
// links one cell to another cell. Can be manually extended with
// sea_dsa_link_<type>(void *p, unsigned offset, <type>> *p2) in order to
// describe what type it is linking to
Expand Down
72 changes: 48 additions & 24 deletions lib/seadsa/DsaLocal.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -12,7 +12,7 @@
//===----------------------------------------------------------------------===//

#include "seadsa/Local.hh"

#include "seadsa/ownsem.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Module.h"
#include "llvm/Pass.h"
Expand Down Expand Up @@ -433,6 +433,7 @@ enum class SeadsaFn {
LINK,
MAKE,
ACCESS,
RET_ALIAS_ARG,
UNKNOWN
};

Expand All @@ -458,8 +459,7 @@ class IntraBlockBuilder : public InstVisitor<IntraBlockBuilder>,
void visitIntToPtrInst(IntToPtrInst &I);
void visitPtrToIntInst(PtrToIntInst &I);
void visitBitCastInst(BitCastInst &I);
void visitCmpInst(CmpInst &I) { /* do nothing */
}
void visitCmpInst(CmpInst &I) { /* do nothing */ }
void visitInsertValueInst(InsertValueInst &I);
void visitExtractValueInst(ExtractValueInst &I);
void visitShuffleVectorInst(ShuffleVectorInst &I);
Expand All @@ -479,22 +479,28 @@ class IntraBlockBuilder : public InstVisitor<IntraBlockBuilder>,
void visitAllocWrapperCall(CallBase &I);
void visitAllocationFnCall(CallBase &I);


SeadsaFn getSeaDsaFn(const Function *fn) {
if (!fn) return SeadsaFn::UNKNOWN;

SeadsaFn fnType = StringSwitch<SeadsaFn>(fn->getName())
.Case("sea_dsa_set_modified", SeadsaFn::MODIFY)
.Case("sea_dsa_set_read", SeadsaFn::READ)
.Case("sea_dsa_set_heap", SeadsaFn::HEAP)
.Case("sea_dsa_set_ptrtoint", SeadsaFn::PTR_TO_INT)
.Case("sea_dsa_set_inttoptr", SeadsaFn::INT_TO_PTR)
.Case("sea_dsa_set_extern", SeadsaFn::EXTERN)
.Case("sea_dsa_alias", SeadsaFn::ALIAS)
.Case("sea_dsa_collapse", SeadsaFn::COLLAPSE)
.Case("sea_dsa_mk_seq", SeadsaFn::MAKE_SEQ)
.Case("sea_dsa_mk", SeadsaFn::MAKE)
.Default(SeadsaFn::UNKNOWN);
SeadsaFn fnType =
StringSwitch<SeadsaFn>(fn->getName())
.Case("sea_dsa_set_modified", SeadsaFn::MODIFY)
.Case("sea_dsa_set_read", SeadsaFn::READ)
.Case("sea_dsa_set_heap", SeadsaFn::HEAP)
.Case("sea_dsa_set_ptrtoint", SeadsaFn::PTR_TO_INT)
.Case("sea_dsa_set_inttoptr", SeadsaFn::INT_TO_PTR)
.Case("sea_dsa_set_extern", SeadsaFn::EXTERN)
.Case("sea_dsa_alias", SeadsaFn::ALIAS)
.Case("sea_dsa_collapse", SeadsaFn::COLLAPSE)
.Case("sea_dsa_mk_seq", SeadsaFn::MAKE_SEQ)
.Case("sea_dsa_mk", SeadsaFn::MAKE)
.Cases("sea.mkown", "sea.mkshr", "sea.bor_mkbor", "sea.bor_ptr",
"sea.bor_mksuc", "sea.begin_unique", "sea.end_unique",
"sea.mov", "sea.set_fatptr_slot", "sea.get_fatptr_slot",
SeadsaFn::RET_ALIAS_ARG)
.Cases("sea.bor_mem2reg", "sea.mov_mem2reg", "sea.bor_mkbor_part",
SeadsaFn::RET_ALIAS_ARG)
.Default(SeadsaFn::UNKNOWN);

if (fnType != SeadsaFn::UNKNOWN) return fnType;

Expand All @@ -517,6 +523,12 @@ class IntraBlockBuilder : public InstVisitor<IntraBlockBuilder>,
return n.startswith("sea_dsa_");
}

/// Returns true if \p F is a \p ownsem_ family of functions
static bool isOwnSemFn(const Function *fn) {
if (!fn) return false;
return boost::hana::contains(OWNSEM_BUILTIN_NAMES, fn->getName());
}

// return function pointer to seadsa::Node setter
using seadsaNodeSetterFunc =
std::function<seadsa::Node &(seadsa::Node *, bool)>;
Expand Down Expand Up @@ -1259,6 +1271,20 @@ void IntraBlockBuilder::visitSeaDsaFnCall(CallBase &I) {
return;
}

case SeadsaFn::RET_ALIAS_ARG: {
LOG("sea-dsa-ret-alias", llvm::errs() << "In ret-alias\n";);
Value *inp = I.getOperand(0);
seadsa::Cell inpCell = valueCell(*inp);
assert(!m_graph.hasCell(I));
assert(!inpCell.isNull());
seadsa::Node *inpNode = inpCell.getNode();

seadsa::Node &n = m_graph.mkNode();
m_graph.mkCell(I, seadsa::Cell(n, 0));

n.unify(*inpNode);
return;
}
case SeadsaFn::ALIAS: {
llvm::SmallVector<seadsa::Cell, 8> toMerge;
LOG("sea-dsa-alias", llvm::errs() << "In alias\n";);
Expand Down Expand Up @@ -1445,7 +1471,7 @@ void IntraBlockBuilder::visitCallBase(CallBase &I) {
if (m_allocInfo.isAllocWrapper(*callee)) {
visitAllocWrapperCall(I);
return;
} else if (isSeaDsaFn(callee)) {
} else if (isSeaDsaFn(callee) || isOwnSemFn(callee)) {
visitSeaDsaFnCall(I);
return;
} else if (callee->isDeclaration()) {
Expand All @@ -1463,7 +1489,6 @@ void IntraBlockBuilder::visitCallBase(CallBase &I) {
// a function that does not return a pointer is a noop
if (!I.getType()->isPointerTy()) return;


// -- something unexpected. Keep an assert so that we know that something
// -- unexpected happened.

Expand Down Expand Up @@ -1716,10 +1741,9 @@ void BlockBuilderBase::visitCastIntToPtr(const Value &dest) {
n.setAlloca();
m_graph.mkCell(dest, seadsa::Cell(n, 0));
if (shouldBeTrackedIntToPtr(dest) && !m_graph.isFlat())
LOG("dsa-warn",
llvm::errs()
<< "WARNING: " << dest << " @ addr " << &dest
<< " is (unsoundly) assumed to point to a fresh memory region.\n";);
LOG("dsa-warn", llvm::errs() << "WARNING: " << dest << " @ addr " << &dest
<< " is (unsoundly) assumed to point to a "
"fresh memory region.\n";);
}

void IntraBlockBuilder::visitIntToPtrInst(IntToPtrInst &I) {
Expand Down Expand Up @@ -1771,8 +1795,8 @@ bool isEscapingPtrToInt(const PtrToIntInst &def) {
if (auto *CI = dyn_cast<const CallInst>(user)) {
const Function *callee = CI->getCalledFunction();
if (callee) {
// callee might not access memory but it can return ptrtoint passed to
// it if (callee->doesNotAccessMemory())
// callee might not access memory but it can return ptrtoint passed
// to it if (callee->doesNotAccessMemory())
// continue;
auto n = callee->getName();
if (n.startswith("__sea_set_extptr_slot") ||
Expand Down

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