Subtree merged in andrew reiter

Author: msuiche

Security Research and Development with LLVM - Andrew Reiter/.gitignore

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+*~

Security Research and Development with LLVM - Andrew Reiter/README.md

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+
+This repo contains some materials related to a talk
+on security r&d projects that in some way use LLVM 
+for doing their work.
+
+
+- projects.md is a list of such projects
+- code is a set of very basic, example code to help those interested in getting up to speed with some basics of LLVM. Don't hate.
+- slides is the slide deck
+
+#### Again on the code
+I must repeat myself: the provided code is only meant to be basic helpers for learning about LLVM
+and is not meant to be some new awesome tool (sadly, no). There is a great deal of research in 
+dynamic and program analysis that is being done and the goal of this code is to make it so you
+can start to more easily read some of the code from those projects ... and then make sense of it.
+This is to avoid getting lost in code versus meaning.
+
+

Security Research and Development with LLVM - Andrew Reiter/code/README.md

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+Very basic example codes.
+
+- bbskel: BasicBlock pass skeleton
+- cgspskel: CallGraphSCC pass skeleton
+- comminute: tool illustrating pass mgr, pass deps, and more
+- fpskel: FunctionPass skeleton
+- intflip: integer argument randomizer|bit-flipper
+- mpskel: ModulePass skeleton
+- npassert: NULL pointer check insertion
+- rpskel: RegionPass skeleton
+- visitorskel: Using a InstVisitor class
+
+

Security Research and Development with LLVM - Andrew Reiter/code/bbskel/Makefile

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+LLVM_VER=3.9
+LLVM_HOME=/usr/bin
+LLVM_CONFIG?=$(LLVM_HOME)/llvm-config-$(LLVM_VER)
+
+ifndef VERBOSE
+QUIET:=@
+endif
+
+SRC_DIR?=$(PWD)/src
+
+CXX=$(LLVM_HOME)/clang++-$(LLVM_VER)
+CC=$(LLVM_HOME)/clang-$(LLVM_VER)
+OPT=$(LLVM_HOME)/opt-$(LLVM_VER)
+DIS=$(LLVM_HOME)/llvm-dis-$(LLVM_VER)
+LNK=$(LLVM_HOME)/llvm-link-$(LLVM_VER)
+
+LDFLAGS+=$(shell $(LLVM_CONFIG) --ldflags) 
+LDFLAGS+=-shared -Wl,-O1
+
+CXXFLAGS+=-I$(shell $(LLVM_CONFIG) --includedir)
+CXXFLAGS+=-std=c++11 -fPIC -fvisibility-inlines-hidden
+CXXFLAGS+=-Wall -Wextra -g -Wno-unused-parameter -Wno-unused-variable
+
+CPPFLAGS+=$(shell $(LLVM_CONFIG) --cppflags)
+CPPFLAGS+=-I$(SRC_DIR)
+
+
+PASS=BBSkel.so
+PASS_OBJECTS=BBSkel.o
+
+default: prep $(PASS)
+
+prep:
+	$(QUIET)mkdir -p built
+	
+%.o : $(SRC_DIR)/%.cpp
+	@echo Compiling $*.cpp
+	$(QUIET)$(CXX) -o built/$*.o -c $(CPPFLAGS) $(CXXFLAGS) $<
+
+$(PASS) : $(PASS_OBJECTS)
+	@echo Linking $@
+	$(QUIET)$(CXX) -o built/$@ $(LDFLAGS) $(CXXFLAGS)  built/*.o
+
+clean:
+	$(QUIET)rm -rf built test/*.bc
+
+
+tests:
+	$(CC) -emit-llvm -o test/foo.bc -c test/foo.c
+
+runtests:
+	$(OPT) -load built/BBSkel.so -mem2reg -bbskel < test/foo.bc

Security Research and Development with LLVM - Andrew Reiter/code/bbskel/README.md

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+
+# BBSkel
+
+This is a basic block pass skeleton. Note, there are also
+loop passes, region passes, etc.
+
+
+# Build & Run
+
+First check the Makefile to set path to llvm-config and version.
+3.8, 3.9 should be fine, so should 4.0
+
+```
+$ make
+$ opt-X.Y -load built/BBSkel.so -bbskel < file.bc
+...
+$
+```
+
+

Security Research and Development with LLVM - Andrew Reiter/code/bbskel/src/BBSkel.cpp

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+#include "llvm/IR/Module.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+#include "BBSkel.h"
+
+void
+BBSkel::getAnalysisUsage(AnalysisUsage &AU) const
+{
+	// No changes to CFG, so tell the pass manager
+	AU.setPreservesCFG(); 
+}
+
+bool
+BBSkel::doFinalization(Function &F)
+{
+	errs() << "#BBs: " << bbcount << "\n";
+	errs() << "#Is: " << icount << "\n";
+	return false;
+}
+
+bool
+BBSkel::runOnBasicBlock(BasicBlock &B)
+{
+	bbcount++;
+	errs() << "  Basic Block found:\n";
+	for (auto &I : B) { // Iterate through instructions in the block
+		++icount;
+		//  Note in output if instruction is a call/invoke
+		if (isa<CallInst>(I) || isa<InvokeInst>(I)) {
+			errs() << " C ";
+		} else {
+			errs() << "   ";
+		}
+		I.dump();
+		errs() << "    used by:\n";	
+		// Go through and dump the uses for each instruction.
+		for (auto ui = I.user_begin(); ui != I.user_end(); ++ui) {
+			errs() << "     U: ";
+			ui->dump();
+		}
+		errs() << " ~~~~ \n";
+	}
+	errs() << "  --- end of basic block ---\n";
+
+	// return true if CFG has changed.
+	return false;
+}
+
+
+
+/*
+ * Register this pass to be made usable.
+ * Needs the static ID initialized and the pass declaration given.
+ */
+char BBSkel::ID = 0;
+static RegisterPass<BBSkel> XX("bbskel", "BasicBlock Pass Skeleton");
+

Security Research and Development with LLVM - Andrew Reiter/code/bbskel/src/BBSkel.h

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+#ifndef	__BBSKEL_H
+#define	__BBSKEL_H
+
+struct BBSkel : public BasicBlockPass {
+	/*
+	 * For all of your passes you will need this and to define it.
+	 * It's address is used by pass system, so the value does not matter.
+	 */
+	static char ID;
+
+	unsigned bbcount;
+	unsigned icount;
+
+	BBSkel() : BasicBlockPass(ID) {
+		bbcount = 0;
+		icount = 0;
+	}
+
+	// Called on each BasicBlock in given compilation unit 
+	virtual bool runOnBasicBlock(BasicBlock &);
+
+	/*
+	 * Used to help order passes by pass manager.
+	 * Declare any passes you need run prior here.. as well as
+	 * any information such as preserving CFG or similar. 
+	 */
+	virtual void getAnalysisUsage(AnalysisUsage &) const;
+
+	/*
+	 * Called after each exec of a runOnBasicBlock.
+	 */
+	virtual bool doFinalization(Function &);
+};
+
+#endif

Security Research and Development with LLVM - Andrew Reiter/code/bbskel/test/foo.c

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+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+
+void
+leaks_passwd()
+{
+	char *p;
+	struct addrinfo hints, *result;
+
+	p = getpass("enter passwd: ");
+	memset(&hints, 0, sizeof(struct addrinfo));
+	hints.ai_family = AF_UNSPEC;
+	hints.ai_socktype = SOCK_DGRAM;
+	hints.ai_flags = 0;
+	hints.ai_protocol = 0;
+	(void)getaddrinfo(p, "http", &hints, &result);
+}
+
+int
+main(int argc, char **argv)
+{
+	leaks_passwd();
+	return 0;
+}

Security Research and Development with LLVM - Andrew Reiter/code/cgsskel/Makefile

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+LLVM_VER=3.9
+LLVM_HOME=/usr/bin
+LLVM_CONFIG?=$(LLVM_HOME)/llvm-config-$(LLVM_VER)
+
+ifndef VERBOSE
+QUIET:=@
+endif
+
+SRC_DIR?=$(PWD)/src
+
+CXX=$(LLVM_HOME)/clang++-$(LLVM_VER)
+CC=$(LLVM_HOME)/clang-$(LLVM_VER)
+OPT=$(LLVM_HOME)/opt-$(LLVM_VER)
+DIS=$(LLVM_HOME)/llvm-dis-$(LLVM_VER)
+LNK=$(LLVM_HOME)/llvm-link-$(LLVM_VER)
+
+LDFLAGS+=$(shell $(LLVM_CONFIG) --ldflags) 
+LDFLAGS+=-shared -Wl,-O1
+
+CXXFLAGS+=-I$(shell $(LLVM_CONFIG) --includedir)
+CXXFLAGS+=-std=c++11 -fPIC -fvisibility-inlines-hidden
+CXXFLAGS+=-Wall -Wextra -g -Wno-unused-parameter -Wno-unused-variable
+
+CPPFLAGS+=$(shell $(LLVM_CONFIG) --cppflags)
+CPPFLAGS+=-I$(SRC_DIR)
+
+PASS=CGSSkel.so
+PASS_OBJECTS=CGSSkel.o
+
+default: prep $(PASS)
+
+prep:
+	$(QUIET)mkdir -p built
+	
+%.o : $(SRC_DIR)/%.cpp
+	@echo Compiling $*.cpp
+	$(QUIET)$(CXX) -o built/$*.o -c $(CPPFLAGS) $(CXXFLAGS) $<
+
+$(PASS) : $(PASS_OBJECTS)
+	@echo Linking $@
+	$(QUIET)$(CXX) -o built/$@ $(LDFLAGS) $(CXXFLAGS)  built/*.o
+
+clean:
+	$(QUIET)rm -rf built test/*.bc
+
+
+tests:
+	$(CC) -emit-llvm -o test/foo.bc -c test/foo.c
+
+runtests:
+	$(OPT) -load built/CGSSkel.so -cgsskel < test/foo.bc

Security Research and Development with LLVM - Andrew Reiter/code/cgsskel/README.md

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+
+# CallGraphSCCPass Skeleton 
+
+Bottom up style to assist to use + augment for CG building
+
+# Build & Run
+
+First check the Makefile to set path to llvm-config and version.
+3.8, 3.9 should be fine, so should 4.0
+
+```
+$ make
+$ opt-X.Y -load built/CGSSkel.so -cgsskel < file.bc
+...
+$
+```
+
+