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authorMichael Rodler <michael.rodler@paluno.uni-due.de>2021-02-15 16:45:36 +0100
committerMichael Rodler <michael.rodler@paluno.uni-due.de>2021-02-15 19:13:50 +0100
commit52124813524fb0a28543066e70c86396931270a3 (patch)
treec0d0e34044aa0f49452cf888153bd8ea3542de47
parent145c673a80878d92013882eda6ef56e6948c397b (diff)
downloadafl++-52124813524fb0a28543066e70c86396931270a3.tar.gz
CMPLOG llvm pass: use CreateIntCast to cast to the right integer type
-rw-r--r--instrumentation/cmplog-instructions-pass.cc165
1 files changed, 27 insertions, 138 deletions
diff --git a/instrumentation/cmplog-instructions-pass.cc b/instrumentation/cmplog-instructions-pass.cc
index 6b071b48..9cd99f85 100644
--- a/instrumentation/cmplog-instructions-pass.cc
+++ b/instrumentation/cmplog-instructions-pass.cc
@@ -19,12 +19,13 @@
#include <stdlib.h>
#include <unistd.h>
+#include <iostream>
#include <list>
#include <string>
#include <fstream>
#include <sys/time.h>
-#include "llvm/Config/llvm-config.h"
+#include "llvm/Config/llvm-config.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/LegacyPassManager.h"
@@ -323,38 +324,8 @@ bool CmpLogInstructions::hookInstrs(Module &M) {
Value *CompareTo = Val;
if (do_cast) {
-
- ConstantInt *cint = dyn_cast<ConstantInt>(Val);
- if (cint) {
-
- uint64_t val = cint->getZExtValue();
- // fprintf(stderr, "ConstantInt: %lu\n", val);
- switch (cast_size) {
-
- case 8:
- CompareTo = ConstantInt::get(Int8Ty, val);
- break;
- case 16:
- CompareTo = ConstantInt::get(Int16Ty, val);
- break;
- case 32:
- CompareTo = ConstantInt::get(Int32Ty, val);
- break;
- case 64:
- CompareTo = ConstantInt::get(Int64Ty, val);
- break;
- case 128:
- CompareTo = ConstantInt::get(Int128Ty, val);
- break;
-
- }
-
- } else {
-
- CompareTo = IRB.CreateBitCast(Val, IntegerType::get(C, cast_size));
-
- }
-
+ CompareTo =
+ IRB.CreateIntCast(CompareTo, IntegerType::get(C, cast_size), false);
}
for (SwitchInst::CaseIt i = SI->case_begin(), e = SI->case_end(); i != e;
@@ -374,29 +345,8 @@ bool CmpLogInstructions::hookInstrs(Module &M) {
Value *new_param = cint;
if (do_cast) {
-
- uint64_t val = cint->getZExtValue();
- // fprintf(stderr, "ConstantInt: %lu\n", val);
- switch (cast_size) {
-
- case 8:
- new_param = ConstantInt::get(Int8Ty, val);
- break;
- case 16:
- new_param = ConstantInt::get(Int16Ty, val);
- break;
- case 32:
- new_param = ConstantInt::get(Int32Ty, val);
- break;
- case 64:
- new_param = ConstantInt::get(Int64Ty, val);
- break;
- case 128:
- new_param = ConstantInt::get(Int128Ty, val);
- break;
-
- }
-
+ new_param =
+ IRB.CreateIntCast(cint, IntegerType::get(C, cast_size), false);
}
if (new_param) {
@@ -604,88 +554,27 @@ bool CmpLogInstructions::hookInstrs(Module &M) {
}
- if (do_cast) {
-
- // F*cking LLVM optimized out any kind of bitcasts of ConstantInt values
- // creating illegal calls. WTF. So we have to work around this.
-
- ConstantInt *cint = dyn_cast<ConstantInt>(op0);
- if (cint) {
-
- uint64_t val = cint->getZExtValue();
- // fprintf(stderr, "ConstantInt: %lu\n", val);
- ConstantInt *new_param = NULL;
- switch (cast_size) {
-
- case 8:
- new_param = ConstantInt::get(Int8Ty, val);
- break;
- case 16:
- new_param = ConstantInt::get(Int16Ty, val);
- break;
- case 32:
- new_param = ConstantInt::get(Int32Ty, val);
- break;
- case 64:
- new_param = ConstantInt::get(Int64Ty, val);
- break;
- case 128:
- new_param = ConstantInt::get(Int128Ty, val);
- break;
-
- }
-
- if (!new_param) { continue; }
- args.push_back(new_param);
-
- } else {
-
- Value *V0 = IRB.CreateBitCast(op0, IntegerType::get(C, cast_size));
- args.push_back(V0);
-
- }
-
- cint = dyn_cast<ConstantInt>(op1);
- if (cint) {
-
- uint64_t val = cint->getZExtValue();
- ConstantInt *new_param = NULL;
- switch (cast_size) {
-
- case 8:
- new_param = ConstantInt::get(Int8Ty, val);
- break;
- case 16:
- new_param = ConstantInt::get(Int16Ty, val);
- break;
- case 32:
- new_param = ConstantInt::get(Int32Ty, val);
- break;
- case 64:
- new_param = ConstantInt::get(Int64Ty, val);
- break;
- case 128:
- new_param = ConstantInt::get(Int128Ty, val);
- break;
-
- }
-
- if (!new_param) { continue; }
- args.push_back(new_param);
-
- } else {
-
- Value *V1 = IRB.CreateBitCast(op1, IntegerType::get(C, cast_size));
- args.push_back(V1);
-
- }
-
- } else {
-
- args.push_back(op0);
- args.push_back(op1);
-
- }
+ // errs() << "[CMPLOG] cmp " << *cmpInst << "(in function " <<
+ // cmpInst->getFunction()->getName() << ")\n";
+
+ // first bitcast to integer type of the same bitsize as the original
+ // type (this is a nop, if already integer)
+ Value *op0_i = IRB.CreateBitCast(
+ op0, IntegerType::get(C, op0->getType()->getPrimitiveSizeInBits()));
+ // then create a int cast, which does zext, trunc or bitcast. In our case
+ // usually zext to the next larger supported type (this is a nop if
+ // already the right type)
+ Value *V0 =
+ IRB.CreateIntCast(op0_i, IntegerType::get(C, cast_size), false);
+ args.push_back(V0);
+ Value *op1_i = IRB.CreateBitCast(
+ op1, IntegerType::get(C, op1->getType()->getPrimitiveSizeInBits()));
+ Value *V1 =
+ IRB.CreateIntCast(op1_i, IntegerType::get(C, cast_size), false);
+ args.push_back(V1);
+
+ // errs() << "[CMPLOG] casted parameters:\n0: " << *V0 << "\n1: " << *V1
+ // << "\n";
ConstantInt *attribute = ConstantInt::get(Int8Ty, attr);
args.push_back(attribute);