preliminary stuff for AFL_MAP_SIZE and afl-llvm-pass

3 files changed, 69 insertions, 5 deletions

diff --git a/llvm_mode/afl-llvm-lto-instrumentation.so.cc b/llvm_mode/afl-llvm-lto-instrumentation.so.cc
index a5058974..ece3201f 100644
--- a/llvm_mode/afl-llvm-lto-instrumentation.so.cc
+++ b/llvm_mode/afl-llvm-lto-instrumentation.so.cc
@@ -637,7 +637,7 @@ bool AFLLTOPass::runOnModule(Module &M) {
     if (!f) {
 
       fprintf(stderr,
-              "Error: init function could not be found (this hould not "
+              "Error: init function could not be found (this should not "
               "happen)\n");
       exit(-1);
 
diff --git a/llvm_mode/afl-llvm-pass.so.cc b/llvm_mode/afl-llvm-pass.so.cc
index b4249802..71abcd05 100644
--- a/llvm_mode/afl-llvm-pass.so.cc
+++ b/llvm_mode/afl-llvm-pass.so.cc
@@ -125,6 +125,7 @@ class AFLCoverage : public ModulePass {
   std::list<std::string> myWhitelist;
   uint32_t               ngram_size = 0;
   uint32_t               debug = 0;
+  uint32_t               map_size = MAP_SIZE;
   char *                 ctx_str = NULL;
 
 };
@@ -192,6 +193,19 @@ bool AFLCoverage::runOnModule(Module &M) {
 
     be_quiet = 1;
 
+  /*
+    char *ptr;
+    if ((ptr = getenv("AFL_MAP_SIZE")) || (ptr = getenv("AFL_MAPSIZE"))) {
+
+      map_size = atoi(ptr);
+      if (map_size < 8 || map_size > (1 << 29))
+        FATAL("illegal AFL_MAP_SIZE %u, must be between 2^3 and 2^30",
+    map_size); if (map_size % 8) map_size = (((map_size >> 3) + 1) << 3);
+
+    }
+
+  */
+
   /* Decide instrumentation ratio */
 
   char *       inst_ratio_str = getenv("AFL_INST_RATIO");
@@ -365,7 +379,7 @@ bool AFLCoverage::runOnModule(Module &M) {
       // if yes we store a context ID for this function in the global var
       if (has_calls) {
 
-        ConstantInt *NewCtx = ConstantInt::get(Int32Ty, AFL_R(MAP_SIZE));
+        ConstantInt *NewCtx = ConstantInt::get(Int32Ty, AFL_R(map_size));
         StoreInst *  StoreCtx = IRB.CreateStore(NewCtx, AFLContext);
         StoreCtx->setMetadata(M.getMDKindID("nosanitize"),
                               MDNode::get(C, None));
@@ -509,7 +523,7 @@ bool AFLCoverage::runOnModule(Module &M) {
       /* Make up cur_loc */
 
       // cur_loc++;
-      cur_loc = AFL_R(MAP_SIZE);
+      cur_loc = AFL_R(map_size);
 
 /* There is a problem with Ubuntu 18.04 and llvm 6.0 (see issue #63).
    The inline function successors() is not inlined and also not found at runtime
@@ -705,6 +719,56 @@ bool AFLCoverage::runOnModule(Module &M) {
 
   }
 
+  /*
+    // This is currently disabled because we not only need to create/insert a
+    // function (easy), but also add it as a constructor with an ID < 5
+
+    if (getenv("AFL_LLVM_DONTWRITEID") == NULL) {
+
+      // yes we could create our own function, insert it into ctors ...
+      // but this would be a pain in the butt ... so we use afl-llvm-rt.o
+
+      Function *f = ...
+
+      if (!f) {
+
+        fprintf(stderr,
+                "Error: init function could not be created (this should not
+    happen)\n"); exit(-1);
+
+      }
+
+      ... constructor for f = 4
+
+      BasicBlock *bb = &f->getEntryBlock();
+      if (!bb) {
+
+        fprintf(stderr,
+                "Error: init function does not have an EntryBlock (this should
+    not happen)\n"); exit(-1);
+
+      }
+
+      BasicBlock::iterator IP = bb->getFirstInsertionPt();
+      IRBuilder<>          IRB(&(*IP));
+
+      if (map_size <= 0x800000) {
+
+        GlobalVariable *AFLFinalLoc = new GlobalVariable(
+            M, Int32Ty, true, GlobalValue::ExternalLinkage, 0,
+            "__afl_final_loc", 0, GlobalVariable::GeneralDynamicTLSModel, 0,
+            false);
+        ConstantInt *const_loc = ConstantInt::get(Int32Ty, map_size);
+        StoreInst *  StoreFinalLoc = IRB.CreateStore(const_loc, AFLFinalLoc);
+        StoreFinalLoc->setMetadata(M.getMDKindID("nosanitize"),
+                                     MDNode::get(C, None));
+
+      }
+
+    }
+
+  */
+
   /* Say something nice. */
 
   if (!be_quiet) {
diff --git a/src/afl-showmap.c b/src/afl-showmap.c
index 59c76d41..a11c128a 100644
--- a/src/afl-showmap.c
+++ b/src/afl-showmap.c
@@ -524,8 +524,8 @@ static void usage(u8 *argv0) {
       "size\n"
       "              the target was compiled for\n"
       "AFL_PRELOAD: LD_PRELOAD / DYLD_INSERT_LIBRARIES settings for target\n"
-      "AFL_QUIET: do not print extra informational output"
-      argv0, MEM_LIMIT, doc_path);
+      "AFL_QUIET: do not print extra informational output" argv0,
+      MEM_LIMIT, doc_path);
 
   exit(1);