1 files changed, 45 insertions, 21 deletions

diff --git a/src/afl-cc.c b/src/afl-cc.c
index c3910e6d..ab794877 100644
--- a/src/afl-cc.c
+++ b/src/afl-cc.c
@@ -73,7 +73,8 @@ enum {
   INSTRUMENT_GCC = 6,
   INSTRUMENT_CLANG = 7,
   INSTRUMENT_OPT_CTX = 8,
-  INSTRUMENT_OPT_NGRAM = 16
+  INSTRUMENT_OPT_NGRAM = 16,
+  INSTRUMENT_OPT_CALLER = 32,
 
 };
 
@@ -88,7 +89,7 @@ char instrument_mode_string[18][18] = {
     "GCC",
     "CLANG",
     "CTX",
-    "",
+    "CALLER",
     "",
     "",
     "",
@@ -1273,6 +1274,7 @@ int main(int argc, char **argv, char **envp) {
   }
 
   if (getenv("AFL_LLVM_CTX")) instrument_opt_mode |= INSTRUMENT_OPT_CTX;
+  if (getenv("AFL_LLVM_CALLER")) instrument_opt_mode |= INSTRUMENT_OPT_CALLER;
 
   if (getenv("AFL_LLVM_NGRAM_SIZE")) {
 
@@ -1388,6 +1390,13 @@ int main(int argc, char **argv, char **envp) {
 
       }
 
+      if (strncasecmp(ptr2, "caller", strlen("caller")) == 0) {
+
+        instrument_opt_mode |= INSTRUMENT_OPT_CALLER;
+        setenv("AFL_LLVM_CALLER", "1", 1);
+
+      }
+
       if (strncasecmp(ptr2, "ngram", strlen("ngram")) == 0) {
 
         u8 *ptr3 = ptr2 + strlen("ngram");
@@ -1421,6 +1430,13 @@ int main(int argc, char **argv, char **envp) {
 
   }
 
+  if ((instrument_opt_mode & INSTRUMENT_OPT_CTX) &&
+      (instrument_opt_mode & INSTRUMENT_OPT_CALLER)) {
+
+    FATAL("you cannot set CTX and CALLER together");
+
+  }
+
   if (instrument_opt_mode && instrument_mode == INSTRUMENT_DEFAULT &&
       (compiler_mode == LLVM || compiler_mode == UNSET)) {
 
@@ -1498,12 +1514,13 @@ int main(int argc, char **argv, char **envp) {
         "      CLASSIC              %s      no  yes     module yes yes    "
         "yes\n"
         "        - NORMAL\n"
+        "        - CALLER\n"
         "        - CTX\n"
         "        - NGRAM-{2-16}\n"
         "      INSTRIM                           no  yes     module yes yes "
         "   yes\n"
         "        - NORMAL\n"
-        "        - CTX\n"
+        "        - CALLER\n"
         "        - NGRAM-{2-16}\n"
         "  [GCC_PLUGIN] gcc plugin: %s%s\n"
         "      CLASSIC              DEFAULT      no  yes     no     no  no     "
@@ -1550,7 +1567,10 @@ int main(int argc, char **argv, char **envp) {
         NATIVE_MSG
 
         "  CLASSIC: decision target instrumentation (README.llvm.md)\n"
-        "  CTX:     CLASSIC + callee context (instrumentation/README.ctx.md)\n"
+        "  CALLER:  CLASSIC + single callee context "
+        "(instrumentation/README.ctx.md)\n"
+        "  CTX:     CLASSIC + full callee context "
+        "(instrumentation/README.ctx.md)\n"
         "  NGRAM-x: CLASSIC + previous path "
         "((instrumentation/README.ngram.md)\n"
         "  INSTRIM: Dominator tree (for LLVM <= 6.0) "
@@ -1644,15 +1664,17 @@ int main(int argc, char **argv, char **envp) {
             "  AFL_LLVM_CMPLOG: log operands of comparisons (RedQueen "
             "mutator)\n"
             "  AFL_LLVM_INSTRUMENT: set instrumentation mode:\n"
-            "    CLASSIC, INSTRIM, PCGUARD, LTO, GCC, CLANG, CTX, NGRAM-2 ... "
-            "NGRAM-16\n"
+            "    CLASSIC, INSTRIM, PCGUARD, LTO, GCC, CLANG, CALLER, CTX, "
+            "NGRAM-2 ..-16\n"
             " You can also use the old environment variables instead:\n"
             "  AFL_LLVM_USE_TRACE_PC: use LLVM trace-pc-guard instrumentation\n"
             "  AFL_LLVM_INSTRIM: use light weight instrumentation InsTrim\n"
             "  AFL_LLVM_INSTRIM_LOOPHEAD: optimize loop tracing for speed "
             "(option to INSTRIM)\n"
-            "  AFL_LLVM_CTX: use context sensitive coverage (for CLASSIC and "
-            "INSTRIM)\n"
+            "  AFL_LLVM_CALLER: use single context sensitive coverage (for "
+            "CLASSIC)\n"
+            "  AFL_LLVM_CTX: use full context sensitive coverage (for "
+            "CLASSIC)\n"
             "  AFL_LLVM_NGRAM_SIZE: use ngram prev_loc count coverage (for "
             "CLASSIC & INSTRIM)\n");
 
@@ -1770,7 +1792,7 @@ int main(int argc, char **argv, char **envp) {
   }
 
   if (instrument_opt_mode && compiler_mode != LLVM)
-    FATAL("CTX and NGRAM can only be used in LLVM mode");
+    FATAL("CTX, CALLER and NGRAM can only be used in LLVM mode");
 
   if (!instrument_opt_mode) {
 
@@ -1780,15 +1802,14 @@ int main(int argc, char **argv, char **envp) {
 
   } else {
 
-    if (instrument_opt_mode == INSTRUMENT_OPT_CTX)
+    char *ptr2 = alloc_printf(" + NGRAM-%u", ngram_size);
+    ptr = alloc_printf(
+        "%s%s%s%s", instrument_mode_string[instrument_mode],
+        (instrument_opt_mode & INSTRUMENT_OPT_CTX) ? " + CTX" : "",
+        (instrument_opt_mode & INSTRUMENT_OPT_CALLER) ? " + CALLER" : "",
+        (instrument_opt_mode & INSTRUMENT_OPT_NGRAM) ? ptr2 : "");
 
-      ptr = alloc_printf("%s + CTX", instrument_mode_string[instrument_mode]);
-    else if (instrument_opt_mode == INSTRUMENT_OPT_NGRAM)
-      ptr = alloc_printf("%s + NGRAM-%u",
-                         instrument_mode_string[instrument_mode], ngram_size);
-    else
-      ptr = alloc_printf("%s + CTX + NGRAM-%u",
-                         instrument_mode_string[instrument_mode], ngram_size);
+    ck_free(ptr2);
 
   }
 
@@ -1799,11 +1820,14 @@ int main(int argc, char **argv, char **envp) {
         "(requires LLVM 11 or higher)");
 #endif
 
-  if (instrument_opt_mode && instrument_mode != INSTRUMENT_CLASSIC &&
-      instrument_mode != INSTRUMENT_CFG)
+  if (instrument_opt_mode && instrument_mode == INSTRUMENT_CFG &&
+      instrument_opt_mode & INSTRUMENT_OPT_CTX)
+    FATAL("CFG instrumentation mode supports NGRAM and CALLER, but not CTX.");
+  else if (instrument_opt_mode && instrument_mode != INSTRUMENT_CLASSIC)
+    // we will drop CFG/INSTRIM in the future so do not advertise
     FATAL(
-        "CTX and NGRAM instrumentation options can only be used with LLVM and "
-        "CFG or CLASSIC instrumentation modes!");
+        "CALLER, CTX and NGRAM instrumentation options can only be used with "
+        "the LLVM CLASSIC instrumentation mode.");
 
   if (getenv("AFL_LLVM_SKIP_NEVERZERO") && getenv("AFL_LLVM_NOT_ZERO"))
     FATAL(