sof/scripts/fuzz.sh

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#!/bin/bash
set -e
print_help()
{
cat <<EOFHELP
# Simple wrapper around a libfuzzer test run, as much for
# documentation as direct use. The idea here is really simple: build
# for the Zephyr "native_posix" board (which is a just a x86
# executable for the build host, not an emulated device) and run the
# resulting zephyr.exe file. This specifies a "fuzz_corpus" directory
# to save the seeds that produce useful coverage output for use in
# repeated runs (these are not particularly large, we might consider
# curating and commiting such a seed directory to the tree).
#
# The tool will run until it finds a failure condition. You will see
# MANY errors on stdout from all the randomized input. Don't try to
# capture this, either let it output to a terminal or arrange to keep
# only the last XXX lines after the tool exits.
#
# The only prerequisite to install is a clang compiler on the host.
# Versions 12+ have all been observed to work.
#
# You will need the kconfigs specified below for correct operation,
# but can add more at the end of this script's command line to
# duplicate configurations as needed. Alternatively you can pass
# overlay files in kconfig syntax via:
# fuzz.sh -t 300 -- -DOVERLAY_CONFIG=..., etc...
EOFHELP
}
# To test this test, make the following change locally:
: <<EOF_TEST_PATCH
--- a/src/ipc/ipc3/handler.c
+++ b/src/ipc/ipc3/handler.c
@@ -1609,6 +1609,8 @@ void ipc_boot_complete_msg(struct ipc_cmd_hdr *header, uint32_t data)
void ipc_cmd(struct ipc_cmd_hdr *_hdr)
{
+ __ASSERT(false, "test the IPC3 fuzzer test");
+
struct sof_ipc_cmd_hdr *hdr = ipc_from_hdr(_hdr);
EOF_TEST_PATCH
# When fuzzing IPC4, make the same change in src/ipc/ipc4/handler.c#ipc_cmd()
main()
{
setup
# Parse "$@". getopts stops after '--'
while getopts "ho:t:" opt; do
case "$opt" in
h) print_help; exit 0;;
o) FUZZER_STDOUT="$OPTARG";;
t) TEST_DURATION="$OPTARG";;
*) print_help; exit 1;;
esac
done
# Pass all "$@" arguments remaining after '--' to cmake.
# This also drops _leading_ '--'.
shift $((OPTIND-1))
# Default values
: "${TEST_DURATION:=3}"
: "${FUZZER_STDOUT:=/dev/stdout}" # bashism
west build -d build-fuzz -b native_posix "$SOF_TOP"/app/ -- \
-DCONFIG_ASSERT=y \
-DCONFIG_SYS_HEAP_BIG_ONLY=y \
-DCONFIG_ZEPHYR_NATIVE_DRIVERS=y \
-DCONFIG_ARCH_POSIX_LIBFUZZER=y \
-DCONFIG_ARCH_POSIX_FUZZ_TICKS=100 \
-DCONFIG_ASAN=y "$@"
mkdir -p ./fuzz_corpus
timeoutret=0
date
timeout -k 10 "$TEST_DURATION" >"$FUZZER_STDOUT" build-fuzz/zephyr/zephyr.exe ./fuzz_corpus ||
timeoutret=$?
if [ $timeoutret -eq 124 ]; then
# The current ASAN seems overly sensitive: it frequently (but not always) complains
# loudly that it has been aborted with a so-called DEADLYSIGNAL when the timeout
# command above actually delivers just a gentle TERM by default. Counteracts the
# wrong impression this unpredictable whining can give with a proud "successfully"
# message.
printf '\n\nSuccessfully aborted fuzzer after %d seconds test duration with DEADLYSIGNAL\n' \
"$TEST_DURATION"
else
die 'zephyr.exe fuzzer stopped before timing out: %d\n' $timeoutret
fi
date
}
setup()
{
SOF_TOP=$(cd "$(dirname "$0")/.." && pwd)
export SOF_TOP
export ZEPHYR_TOOLCHAIN_VARIANT=llvm
# ZEPHYR_BASE. Does not seem required.
local WS_TOP
WS_TOP=$(cd "$SOF_TOP"; west topdir)
# The manifest itself is not a west project
ZEP_DIR=$(2>/dev/null west list -f '{path}' zephyr || echo 'zephyr')
export ZEPHYR_BASE="$WS_TOP/$ZEP_DIR"
}
die()
{
>&2 printf '%s ERROR: ' "$0"
# We want die() to be usable exactly like printf
# shellcheck disable=SC2059
>&2 printf "$@"
>&2 printf '\n'
exit 1
}
main "$@"