Fixed #30: CPU affinity settings removed from afl-multicore. (The

option for explicitly setting CPU affinity in afl was dropped in
afl-2.17b.)

Author: rc0r

README.md

@@ -229,16 +229,6 @@ specific target than were previously started. Obviously `afl-multicore` can
 resume just as many afl instances as it finds output directories for! Use the
 `add` command to start additional afl instances!
 
-If you want to use afl's CPU affinity feature use the `cpu_affinity`
-configuration option to provide a whitespace separated list of single (`1`) or
-tuple (`2,3`) CPU ids. For info on when to use single vs. tuple id specifications
-checkout out afl's `docs/perf_tips.txt`. In the `afl-multicore` configuration
-you need to provide a CPU id for **every** afl instance you want to assign to a
-specific CPU core. The first provided id is always used for the master afl
-instance. When starting more afl instances than CPU ids have been specified,
-all additional instances won't be assigned to a specific CPU core.  
-**Note:** Don't use whitespaces in your tuple specifications!
-
 `afl-fuzz` can be run using its `-f <file>` argument to specify the location of
 the generated sample. When using multiple `afl-fuzz` instances a single file
 obviously can't do the trick, because multiple fuzzers running in parallel would

afl_utils/afl_multicore.py

@@ -68,10 +68,6 @@ def afl_cmdline_from_config(config_settings, instance_number):
         afl_cmdline.append("-m")
         afl_cmdline.append(config_settings["mem_limit"])
 
-    if "cpu_affinity" in config_settings and instance_number < len(config_settings["cpu_affinity"]):
-        afl_cmdline.append("-Z")
-        afl_cmdline.append(config_settings["cpu_affinity"][instance_number])
-
     if "qemu" in config_settings and config_settings["qemu"]:
         afl_cmdline.append("-Q")
 

config/afl-multicore.conf.sample

@@ -8,12 +8,6 @@
     "timeout": "200+",
     "mem_limit": "150",
     "qemu": false,
-    "cpu_affinity": [
-        "0,1",
-        "2,3",
-        "4,5",
-        "6,7"
-    ],
     "afl_margs": "-T banner",
     "dirty": false,
     "dumb": false,

docs/CHANGELOG.md

@@ -4,6 +4,9 @@ Version 1.29a
 
   - afl-collect updated to not use a hard-coded path to the gdb binary
     (suggested by Martin Lindhe).
+  - Fixed #30: CPU affinity settings removed from afl-multicore. (The
+    option for explicitly setting CPU affinity in afl was dropped in
+    afl-2.17b.)
 
 Version 1.28a
 

testdata/afl-multicore.conf2.test

@@ -2,11 +2,5 @@
     "target": "/usr/bin/target",
     "input": "./in",
     "cmdline": "-a -b -c -d",
-    "cpu_affinity": [
-        "0,1",
-        "2,3",
-        "4,5",
-        "6,7"
-    ],
     "output": "./out"
 }

tests/test_afl_multicore.py

@@ -45,7 +45,6 @@
     'target': '/usr/bin/target',
     'input': './in',
     'cmdline': '-a -b -c -d',
-    'cpu_affinity': ['0,1', '2,3', '4,5', '6,7'],
     'output': './out'
 }
 
@@ -72,7 +71,7 @@
 ]
 
 test_afl_cmdline2 = [
-   '-Z', '2,3', '-i', './in', '-o', './out'
+    '-i', './in', '-o', './out'
 ]
 
 test_afl_cmdline21 = [