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| -rwxr-xr-x | afl-system-config.sh | 15 | ||||
| -rw-r--r-- | docs/perf_tips.txt | 9 |
2 files changed, 24 insertions, 0 deletions
diff --git a/afl-system-config.sh b/afl-system-config.sh new file mode 100755 index 00000000..88564c20 --- /dev/null +++ b/afl-system-config.sh @@ -0,0 +1,15 @@ +#!/bin/sh +echo This reconfigures the system to have a better fuzzing performance +sysctl -w kernel.core_pattern=core +sysctl -w kernel.randomize_va_space=0 +sysctl -w kernel.sched_child_runs_first=1 +sysctl -w kernel.sched_autogroup_enabled=1 +sysctl -w kernel.sched_migration_cost_ns=50000000 +sysctl -w kernel.sched_latency_ns=250000000 +echo never > /sys/kernel/mm/transparent_hugepage/enabled +echo performance | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor > /dev/null +echo +echo It is recommended to boot the kernel with lots of security off - if you are running a machine that is in a secured network - so set this: +echo '/etc/default/grub:GRUB_CMDLINE_LINUX_DEFAULT="ibpb=off ibrs=off kpti=off l1tf=off mds=off mitigations=off no_stf_barrier noibpb noibrs nopcid nopti nospec_store_bypass_disable nospectre_v1 nospectre_v2 pcid=off pti=off spec_store_bypass_disable=off spectre_v2=off stf_barrier=off"' +echo +echo Also use AFL_TMPDIR to use a tmpfs for the input file diff --git a/docs/perf_tips.txt b/docs/perf_tips.txt index 6906d5ab..799691c7 100644 --- a/docs/perf_tips.txt +++ b/docs/perf_tips.txt @@ -188,6 +188,15 @@ There are several OS-level factors that may affect fuzzing speed: SCHED_RR - can usually speed things up, too, but needs to be done with care. + - Disable all the spectre, meltdown etc. security countermeasures in the + kernel if your machine is properly seperated: + "ibpb=off ibrs=off kpti=off l1tf=off mds=off mitigations=off + no_stf_barrier noibpb noibrs nopcid nopti nospec_store_bypass_disable + nospectre_v1 nospectre_v2 pcid=off pti=off spec_store_bypass_disable=off + spectre_v2=off stf_barrier=off" + In most Linux distributions you can put this into a /etc/default/grub + variable. + 9) If all other options fail, use -d ------------------------------------ |