android: prefer bigcores

docs/ChangeLog

@@ -21,10 +21,12 @@ Version ++2.60d (develop):
   - afl-fuzz:
      - now prints the real python version support compiled in
      - set stronger performance compile options and little tweaks
+     - Android: prefer bigcores when selecting a CPU
   - afl-clang-fast:
      - show in the help output for which llvm version it was compiled for
      - now does not need to be recompiled between trace-pc and pass
        instrumentation. compile normally and set AFL_LLVM_USE_TRACE_PC :)
+     - llvm 11 is supported
   - afl-cmin is now a sh script (invoking awk) instead of bash for portability
     the original script is still present as afl-cmin.bash
   - added blacklist and whitelisting function check in all modules of llvm_mode

llvm_mode/LLVMInsTrim.so.cc

@@ -190,7 +190,8 @@ struct InsTrim : public ModulePass {
 
           if (instFilename.str().empty()) {
 
-            /* If the original location is empty, try using the inlined location */
+            /* If the original location is empty, try using the inlined location
+             */
             DILocation *oDILoc = cDILoc->getInlinedAt();
             if (oDILoc) {
 
@@ -424,8 +425,8 @@ struct InsTrim : public ModulePass {
 
     }
 
-    OKF("Instrumented %u locations (%llu, %llu) (%s mode)\n",
-        total_instr, total_rs, total_hs,
+    OKF("Instrumented %u locations (%llu, %llu) (%s mode)\n", total_instr,
+        total_rs, total_hs,
         getenv("AFL_HARDEN")
             ? "hardened"
             : ((getenv("AFL_USE_ASAN") || getenv("AFL_USE_MSAN"))

src/afl-fuzz-init.c

@@ -184,11 +184,21 @@ void bind_to_free_cpu(void) {
     "For this platform we do not have free CPU binding code yet. If possible, please supply a PR to https://github.com/vanhauser-thc/AFLplusplus"
 #endif
 
-  for (i = 0; i < cpu_core_count; ++i)
-    if (!cpu_used[i]) break;
+  size_t cpu_start = 0;
 
+  try:
+#ifndef __ANDROID__
+    for (i = cpu_start; i < cpu_core_count; i++)
+      if (!cpu_used[i]) break;
   if (i == cpu_core_count) {
 
+#else
+    for (i = cpu_core_count - cpu_start - 1; i > -1; i--)
+      if (!cpu_used[i]) break;
+  if (i == -1) {
+
+#endif
+
     SAYF("\n" cLRD "[-] " cRST
          "Uh-oh, looks like all %d CPU cores on your system are allocated to\n"
          "    other instances of afl-fuzz (or similar CPU-locked tasks). "
@@ -197,12 +207,11 @@ void bind_to_free_cpu(void) {
          "you are\n"
          "    absolutely sure, you can set AFL_NO_AFFINITY and try again.\n",
          cpu_core_count);
-
     FATAL("No more free CPU cores");
 
   }
 
-  OKF("Found a free CPU core, binding to #%u.", i);
+  OKF("Found a free CPU core, try binding to #%u.", i);
 
   cpu_aff = i;
 
@@ -212,22 +221,31 @@ void bind_to_free_cpu(void) {
 #elif defined(__NetBSD__)
   c = cpuset_create();
   if (c == NULL) PFATAL("cpuset_create failed");
-
   cpuset_set(i, c);
 #endif
 
 #if defined(__linux__)
-  if (sched_setaffinity(0, sizeof(c), &c)) PFATAL("sched_setaffinity failed");
+  if (sched_setaffinity(0, sizeof(c), &c)) {
+
+    if (cpu_start == cpu_core_count)
+      PFATAL("sched_setaffinity failed for CPU %d, exit", i);
+    WARNF("sched_setaffinity failed to CPU %d, trying next CPU", i);
+    cpu_start++;
+    goto try
+      ;
+
+  }
+
 #elif defined(__FreeBSD__) || defined(__DragonFly__)
   if (pthread_setaffinity_np(pthread_self(), sizeof(c), &c))
     PFATAL("pthread_setaffinity failed");
 #elif defined(__NetBSD__)
-  if (pthread_setaffinity_np(pthread_self(), cpuset_size(c), c))
-    PFATAL("pthread_setaffinity failed");
+if (pthread_setaffinity_np(pthread_self(), cpuset_size(c), c))
+  PFATAL("pthread_setaffinity failed");
 
-  cpuset_destroy(c);
+cpuset_destroy(c);
 #else
-  // this will need something for other platforms
+// this will need something for other platforms
 #endif
 
 }