add -b option to afl-fuzz

1 files changed, 16 insertions, 3 deletions

diff --git a/src/afl-fuzz.c b/src/afl-fuzz.c
index 5bedf6e1..e33a4bbd 100644
--- a/src/afl-fuzz.c
+++ b/src/afl-fuzz.c
@@ -143,6 +143,8 @@ static void usage(afl_state_t *afl, u8 *argv0, int more_help) {
       //"  -B bitmap.txt - mutate a specific test case, use the out/fuzz_bitmap
       //" "file\n"
       "  -C            - crash exploration mode (the peruvian rabbit thing)\n"
+      "  -b cpu_id     - bind the fuzzing process to the specified CPU core "
+      "(0-...)\n"
       "  -e ext        - file extension for the fuzz test input file (if "
       "needed)\n\n",
       argv0, EXEC_TIMEOUT, MEM_LIMIT, FOREIGN_SYNCS_MAX);
@@ -271,9 +273,9 @@ int main(int argc, char **argv_orig, char **envp) {
 
   afl->shmem_testcase_mode = 1;  // we always try to perform shmem fuzzing
 
-  while ((opt = getopt(argc, argv,
-                       "+c:i:I:o:f:F:m:t:T:dDnCB:S:M:x:QNUWe:p:s:V:E:L:hRP:")) >
-         0) {
+  while ((opt = getopt(
+              argc, argv,
+              "+b:c:i:I:o:f:F:m:t:T:dDnCB:S:M:x:QNUWe:p:s:V:E:L:hRP:")) > 0) {
 
     switch (opt) {
 
@@ -281,6 +283,17 @@ int main(int argc, char **argv_orig, char **envp) {
         afl->infoexec = optarg;
         break;
 
+      case 'b': {                                          /* bind CPU core */
+
+        if (afl->cpu_to_bind != -1) FATAL("Multiple -b options not supported");
+
+        if (sscanf(optarg, "%u", &afl->cpu_to_bind) < 0 || optarg[0] == '-')
+          FATAL("Bad syntax used for -b");
+
+        break;
+
+      }
+
       case 'c': {
 
         afl->shm.cmplog_mode = 1;