fix cmin -T

3 files changed, 13 insertions, 0 deletions

diff --git a/afl-cmin b/afl-cmin
index d0bbed2b..f3ae4304 100755
--- a/afl-cmin
+++ b/afl-cmin
@@ -493,6 +493,11 @@ BEGIN {
     }
   }
 
+  if (in_count < threads) {
+    threads = in_count
+    print "[!] WARNING: less inputs than threads, reducing threads to "threads" and likely the overhead of threading makes things slower..."
+  }
+
   # Let's roll!
 
   #############################
diff --git a/afl-cmin.bash b/afl-cmin.bash
index 1d080491..b326bee8 100755
--- a/afl-cmin.bash
+++ b/afl-cmin.bash
@@ -339,6 +339,13 @@ fi
 echo "[*] Are you aware that afl-cmin is faster than this afl-cmin.bash script?"
 echo "[+] Found $IN_COUNT files for minimizing."
 
+if [ -n "$THREADS" ]; then
+  if [ "$IN_COUNT" -lt "$THREADS" ]; then
+    THREADS=$IN_COUNT
+    echo "[!] WARNING: less inputs than threads, reducing threads to $THREADS and likely the overhead of threading makes things slower..."
+  fi
+fi
+
 FIRST_FILE=`ls "$IN_DIR" | head -1`
 
 # Make sure that we're not dealing with a directory.
diff --git a/docs/Changelog.md b/docs/Changelog.md
index ad58e99e..032bb774 100644
--- a/docs/Changelog.md
+++ b/docs/Changelog.md
@@ -19,6 +19,7 @@
     - fixed a bug inherited from vanilla AFL where a coverage of
       map[123] = 11 would be the same as map[1123] = 1
     - warn on crashing inputs
+    - adjust threads if less inputs than threads specified
   - afl-cc:
     - fixed an off-by-one instrumentation of iselect, hurting coverage a bit.
       Thanks to @amykweon for spotting and fixing!