mirror of
https://github.com/AFLplusplus/AFLplusplus.git
synced 2025-06-16 20:08:07 +00:00
removed gcc_plugin from master
This commit is contained in:
van Hauser
@ -1,23 +0,0 @@
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|||||||
to reproduce:
|
|
||||||
=============
|
|
||||||
tiff-4.0.4.tar.gz
|
|
||||||
CC=afl-gcc-fast CXX=afl-g++-fast ./configure --disable-shared
|
|
||||||
make
|
|
||||||
|
|
||||||
result
|
|
||||||
======
|
|
||||||
[+] Instrumented 11 locations in TIFFInitJPEG
|
|
||||||
during GIMPLE pass: evrp
|
|
||||||
tif_jpeg.c: In function ‘JPEGFixupTagsSubsamplingSec’:
|
|
||||||
tif_jpeg.c:2388:1: internal compiler error: Segmentation fault
|
|
||||||
}
|
|
||||||
^
|
|
||||||
0x7ffff758e83f ???
|
|
||||||
/build/glibc-vjB4T1/glibc-2.28/signal/../sysdeps/unix/sysv/linux/x86_64/sigaction.c:0
|
|
||||||
0x7ffff757b09a __libc_start_main
|
|
||||||
../csu/libc-start.c:308
|
|
||||||
Please submit a full bug report,
|
|
||||||
with preprocessed source if appropriate.
|
|
||||||
Please include the complete backtrace with any bug report.
|
|
||||||
See <file:///usr/share/doc/gcc-8/README.Bugs> for instructions.
|
|
||||||
make[2]: *** [Makefile:696: tif_jpeg.lo] Error 1
|
|
||||||
@ -1,75 +0,0 @@
|
|||||||
#
|
|
||||||
# american fuzzy lop - GCC plugin instrumentation
|
|
||||||
# -----------------------------------------------
|
|
||||||
#
|
|
||||||
# Written by Austin Seipp <aseipp@pobox.com> and
|
|
||||||
# Laszlo Szekeres <lszekeres@google.com> and
|
|
||||||
# Michal Zalewski <lcamtuf@google.com>
|
|
||||||
#
|
|
||||||
# GCC integration design is based on the LLVM design, which comes
|
|
||||||
# from Laszlo Szekeres.
|
|
||||||
#
|
|
||||||
# Copyright 2015 Google Inc. All rights reserved.
|
|
||||||
#
|
|
||||||
# Licensed under the Apache License, Version 2.0 (the "License");
|
|
||||||
# you may not use this file except in compliance with the License.
|
|
||||||
# You may obtain a copy of the License at:
|
|
||||||
#
|
|
||||||
# http://www.apache.org/licenses/LICENSE-2.0
|
|
||||||
#
|
|
||||||
|
|
||||||
PREFIX ?= /usr/local
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|
||||||
HELPER_PATH = $(PREFIX)/lib/afl
|
|
||||||
BIN_PATH = $(PREFIX)/bin
|
|
||||||
|
|
||||||
CFLAGS ?= -O3 -g -funroll-loops
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|
||||||
CFLAGS += -Wall -D_FORTIFY_SOURCE=2 -Wno-pointer-sign \
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|
||||||
-DAFL_PATH=\"$(HELPER_PATH)\" -DBIN_PATH=\"$(BIN_PATH)\" \
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|
||||||
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|
||||||
CXXFLAGS ?= -O3 -g -funroll-loops
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|
||||||
CXXEFLAGS := $(CXXFLAGS) -Wall -D_FORTIFY_SOURCE=2
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|
||||||
|
|
||||||
CC ?= gcc
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|
||||||
CXX ?= g++
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|
||||||
|
|
||||||
PLUGIN_FLAGS = -fPIC -fno-rtti -I"$(shell $(CC) -print-file-name=plugin)/include"
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|
||||||
|
|
||||||
PROGS = ../afl-gcc-fast ../afl-gcc-pass.so ../afl-gcc-rt.o
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|
||||||
|
|
||||||
all: test_deps $(PROGS) test_build all_done
|
|
||||||
|
|
||||||
test_deps:
|
|
||||||
@echo "[*] Checking for working '$(CC)'..."
|
|
||||||
@which $(CC) >/dev/null 2>&1 || ( echo "[-] Oops, can't find '$(CC)'. Make sure that it's in your \$$PATH (or set \$$CC and \$$CXX)."; exit 1 )
|
|
||||||
@echo "[*] Checking for '../afl-showmap'..."
|
|
||||||
@test -f ../afl-showmap || ( echo "[-] Oops, can't find '../afl-showmap'. Be sure to compile AFL first."; exit 1 )
|
|
||||||
@echo "[+] All set and ready to build."
|
|
||||||
|
|
||||||
../afl-gcc-fast: afl-gcc-fast.c | test_deps
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|
||||||
$(CC) $(CFLAGS) $< -o $@ $(LDFLAGS)
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|
||||||
ln -sf afl-gcc-fast ../afl-g++-fast
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|
||||||
|
|
||||||
../afl-gcc-pass.so: afl-gcc-pass.so.cc | test_deps
|
|
||||||
$(CXX) $(CXXEFLAGS) $(PLUGIN_FLAGS) -shared $< -o $@
|
|
||||||
|
|
||||||
../afl-gcc-rt.o: afl-gcc-rt.o.c | test_deps
|
|
||||||
$(CC) $(CFLAGS) -fPIC -c $< -o $@
|
|
||||||
|
|
||||||
test_build: $(PROGS)
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|
||||||
@echo "[*] Testing the CC wrapper and instrumentation output..."
|
|
||||||
unset AFL_USE_ASAN AFL_USE_MSAN; AFL_QUIET=1 AFL_INST_RATIO=100 AFL_PATH=. AFL_CC=$(CC) ../afl-gcc-fast $(CFLAGS) ../test-instr.c -o test-instr $(LDFLAGS)
|
|
||||||
# unset AFL_USE_ASAN AFL_USE_MSAN; AFL_INST_RATIO=100 AFL_PATH=. AFL_CC=$(CC) ../afl-gcc-fast $(CFLAGS) ../test-instr.c -o test-instr $(LDFLAGS)
|
|
||||||
echo 0 | ../afl-showmap -m none -q -o .test-instr0 ./test-instr
|
|
||||||
echo 1 | ../afl-showmap -m none -q -o .test-instr1 ./test-instr
|
|
||||||
@rm -f test-instr
|
|
||||||
@cmp -s .test-instr0 .test-instr1; DR="$$?"; rm -f .test-instr0 .test-instr1; if [ "$$DR" = "0" ]; then echo; echo "Oops, the instrumentation does not seem to be behaving correctly!"; echo; echo "Please ping <lcamtuf@google.com> to troubleshoot the issue."; echo; exit 1; fi
|
|
||||||
@echo "[+] All right, the instrumentation seems to be working!"
|
|
||||||
|
|
||||||
all_done: test_build
|
|
||||||
@echo "[+] All done! You can now use '../afl-gcc-fast' to compile programs."
|
|
||||||
|
|
||||||
.NOTPARALLEL: clean
|
|
||||||
|
|
||||||
clean:
|
|
||||||
rm -f *.o *.so *~ a.out core core.[1-9][0-9]* test-instr .test-instr0 .test-instr1
|
|
||||||
rm -f $(PROGS) ../afl-g++-fast
|
|
||||||
@ -1,163 +0,0 @@
|
|||||||
===========================================
|
|
||||||
Fast GCC-based instrumentation for afl-fuzz
|
|
||||||
===========================================
|
|
||||||
|
|
||||||
(See ../docs/README for the general instruction manual.)
|
|
||||||
(See ../llvm_mode/README.llvm for the LLVM-based instrumentation.)
|
|
||||||
|
|
||||||
|
|
||||||
!!!
|
|
||||||
!!! gcc_plugin is not stable yet and can crash when compiling
|
|
||||||
!!!
|
|
||||||
|
|
||||||
|
|
||||||
1) Introduction
|
|
||||||
---------------
|
|
||||||
|
|
||||||
The code in this directory allows you to instrument programs for AFL using
|
|
||||||
true compiler-level instrumentation, instead of the more crude
|
|
||||||
assembly-level rewriting approach taken by afl-gcc and afl-clang. This has
|
|
||||||
several interesting properties:
|
|
||||||
|
|
||||||
- The compiler can make many optimizations that are hard to pull off when
|
|
||||||
manually inserting assembly. As a result, some slow, CPU-bound programs will
|
|
||||||
run up to around 2x faster.
|
|
||||||
|
|
||||||
The gains are less pronounced for fast binaries, where the speed is limited
|
|
||||||
chiefly by the cost of creating new processes. In such cases, the gain will
|
|
||||||
probably stay within 10%.
|
|
||||||
|
|
||||||
- The instrumentation is CPU-independent. At least in principle, you should
|
|
||||||
be able to rely on it to fuzz programs on non-x86 architectures (after
|
|
||||||
building afl-fuzz with AFL_NOX86=1).
|
|
||||||
|
|
||||||
- Because the feature relies on the internals of GCC, it is gcc-specific
|
|
||||||
and will *not* work with LLVM (see ../llvm_plugin for an alternative).
|
|
||||||
|
|
||||||
Once this implementation is shown to be sufficiently robust and portable, it
|
|
||||||
will probably replace afl-gcc. For now, it can be built separately and
|
|
||||||
co-exists with the original code.
|
|
||||||
|
|
||||||
The idea and much of the implementation comes from Laszlo Szekeres.
|
|
||||||
|
|
||||||
2) How to use
|
|
||||||
-------------
|
|
||||||
|
|
||||||
In order to leverage this mechanism, you need to have GCC and the plugin headers
|
|
||||||
installed on your system. That should be all you need. On Debian machines, these
|
|
||||||
headers can be acquired by installing the `gcc-<VERSION>-plugin-dev` packages.
|
|
||||||
|
|
||||||
To build the instrumentation itself, type 'make'. This will generate binaries
|
|
||||||
called afl-gcc-fast and afl-g++-fast in the parent directory. Once this
|
|
||||||
is done, you can instrument third-party code in a way similar to the standard
|
|
||||||
operating mode of AFL, e.g.:
|
|
||||||
|
|
||||||
CC=/path/to/afl/afl-gcc-fast ./configure [...options...]
|
|
||||||
make
|
|
||||||
|
|
||||||
Be sure to also include CXX set to afl-g++-fast for C++ code.
|
|
||||||
|
|
||||||
The tool honors roughly the same environmental variables as afl-gcc (see
|
|
||||||
../docs/env_variables.txt). This includes AFL_INST_RATIO, AFL_USE_ASAN,
|
|
||||||
AFL_HARDEN, and AFL_DONT_OPTIMIZE.
|
|
||||||
|
|
||||||
Note: if you want the GCC plugin to be installed on your system for all
|
|
||||||
users, you need to build it before issuing 'make install' in the parent
|
|
||||||
directory.
|
|
||||||
|
|
||||||
3) Gotchas, feedback, bugs
|
|
||||||
--------------------------
|
|
||||||
|
|
||||||
This is an early-stage mechanism, so field reports are welcome. You can send bug
|
|
||||||
reports to <aseipp@pobox.com>.
|
|
||||||
|
|
||||||
4) Bonus feature #1: deferred initialization
|
|
||||||
--------------------------------------------
|
|
||||||
|
|
||||||
AFL tries to optimize performance by executing the targeted binary just once,
|
|
||||||
stopping it just before main(), and then cloning this "master" process to get
|
|
||||||
a steady supply of targets to fuzz.
|
|
||||||
|
|
||||||
Although this approach eliminates much of the OS-, linker- and libc-level
|
|
||||||
costs of executing the program, it does not always help with binaries that
|
|
||||||
perform other time-consuming initialization steps - say, parsing a large config
|
|
||||||
file before getting to the fuzzed data.
|
|
||||||
|
|
||||||
In such cases, it's beneficial to initialize the forkserver a bit later, once
|
|
||||||
most of the initialization work is already done, but before the binary attempts
|
|
||||||
to read the fuzzed input and parse it; in some cases, this can offer a 10x+
|
|
||||||
performance gain. You can implement delayed initialization in LLVM mode in a
|
|
||||||
fairly simple way.
|
|
||||||
|
|
||||||
First, locate a suitable location in the code where the delayed cloning can
|
|
||||||
take place. This needs to be done with *extreme* care to avoid breaking the
|
|
||||||
binary. In particular, the program will probably malfunction if you select
|
|
||||||
a location after:
|
|
||||||
|
|
||||||
- The creation of any vital threads or child processes - since the forkserver
|
|
||||||
can't clone them easily.
|
|
||||||
|
|
||||||
- The initialization of timers via setitimer() or equivalent calls.
|
|
||||||
|
|
||||||
- The creation of temporary files, network sockets, offset-sensitive file
|
|
||||||
descriptors, and similar shared-state resources - but only provided that
|
|
||||||
their state meaningfully influences the behavior of the program later on.
|
|
||||||
|
|
||||||
- Any access to the fuzzed input, including reading the metadata about its
|
|
||||||
size.
|
|
||||||
|
|
||||||
With the location selected, add this code in the appropriate spot:
|
|
||||||
|
|
||||||
#ifdef __AFL_HAVE_MANUAL_CONTROL
|
|
||||||
__AFL_INIT();
|
|
||||||
#endif
|
|
||||||
|
|
||||||
You don't need the #ifdef guards, but they will make the program still work as
|
|
||||||
usual when compiled with a tool other than afl-gcc-fast/afl-clang-fast.
|
|
||||||
|
|
||||||
Finally, recompile the program with afl-gcc-fast (afl-gcc or afl-clang will
|
|
||||||
*not* generate a deferred-initialization binary) - and you should be all set!
|
|
||||||
|
|
||||||
5) Bonus feature #2: persistent mode
|
|
||||||
------------------------------------
|
|
||||||
|
|
||||||
Some libraries provide APIs that are stateless, or whose state can be reset in
|
|
||||||
between processing different input files. When such a reset is performed, a
|
|
||||||
single long-lived process can be reused to try out multiple test cases,
|
|
||||||
eliminating the need for repeated fork() calls and the associated OS overhead.
|
|
||||||
|
|
||||||
The basic structure of the program that does this would be:
|
|
||||||
|
|
||||||
while (__AFL_LOOP(1000)) {
|
|
||||||
|
|
||||||
/* Read input data. */
|
|
||||||
/* Call library code to be fuzzed. */
|
|
||||||
/* Reset state. */
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Exit normally */
|
|
||||||
|
|
||||||
The numerical value specified within the loop controls the maximum number
|
|
||||||
of iterations before AFL will restart the process from scratch. This minimizes
|
|
||||||
the impact of memory leaks and similar glitches; 1000 is a good starting point.
|
|
||||||
|
|
||||||
A more detailed template is shown in ../experimental/persistent_demo/.
|
|
||||||
Similarly to the previous mode, the feature works only with afl-gcc-fast or
|
|
||||||
afl-clang-fast; #ifdef guards can be used to suppress it when using other
|
|
||||||
compilers.
|
|
||||||
|
|
||||||
Note that as with the previous mode, the feature is easy to misuse; if you
|
|
||||||
do not reset the critical state fully, you may end up with false positives or
|
|
||||||
waste a whole lot of CPU power doing nothing useful at all. Be particularly
|
|
||||||
wary of memory leaks and the state of file descriptors.
|
|
||||||
|
|
||||||
When running in this mode, the execution paths will inherently vary a bit
|
|
||||||
depending on whether the input loop is being entered for the first time or
|
|
||||||
executed again. To avoid spurious warnings, the feature implies
|
|
||||||
AFL_NO_VAR_CHECK and hides the "variable path" warnings in the UI.
|
|
||||||
|
|
||||||
PS. Because there are task switches still involved, the mode isn't as fast as
|
|
||||||
"pure" in-process fuzzing offered, say, by LLVM's LibFuzzer; but it is a lot
|
|
||||||
faster than the normal fork() model, and compared to in-process fuzzing,
|
|
||||||
should be a lot more robust.
|
|
||||||
@ -1,283 +0,0 @@
|
|||||||
/*
|
|
||||||
american fuzzy lop - GCC wrapper for GCC plugin
|
|
||||||
------------------------------------------------
|
|
||||||
|
|
||||||
Written by Austin Seipp <aseipp@pobox.com> and
|
|
||||||
Laszlo Szekeres <lszekeres@google.com> and
|
|
||||||
Michal Zalewski <lcamtuf@google.com>
|
|
||||||
|
|
||||||
GCC integration design is based on the LLVM design, which comes
|
|
||||||
from Laszlo Szekeres.
|
|
||||||
|
|
||||||
Copyright 2015 Google Inc. All rights reserved.
|
|
||||||
|
|
||||||
Licensed under the Apache License, Version 2.0 (the "License");
|
|
||||||
you may not use this file except in compliance with the License.
|
|
||||||
You may obtain a copy of the License at:
|
|
||||||
|
|
||||||
http://www.apache.org/licenses/LICENSE-2.0
|
|
||||||
|
|
||||||
This program is a drop-in replacement for gcc, similar in most
|
|
||||||
respects to ../afl-gcc, but with compiler instrumentation through a
|
|
||||||
plugin. It tries to figure out compilation mode, adds a bunch of
|
|
||||||
flags, and then calls the real compiler.
|
|
||||||
|
|
||||||
*/
|
|
||||||
|
|
||||||
#define AFL_MAIN
|
|
||||||
|
|
||||||
#include "../config.h"
|
|
||||||
#include "../types.h"
|
|
||||||
#include "../debug.h"
|
|
||||||
#include "../alloc-inl.h"
|
|
||||||
|
|
||||||
#include <stdio.h>
|
|
||||||
#include <unistd.h>
|
|
||||||
#include <stdlib.h>
|
|
||||||
#include <string.h>
|
|
||||||
|
|
||||||
static u8* obj_path; /* Path to runtime libraries */
|
|
||||||
static u8** cc_params; /* Parameters passed to the real CC */
|
|
||||||
static u32 cc_par_cnt = 1; /* Param count, including argv0 */
|
|
||||||
|
|
||||||
|
|
||||||
/* Try to find the runtime libraries. If that fails, abort. */
|
|
||||||
|
|
||||||
static void find_obj(u8* argv0) {
|
|
||||||
|
|
||||||
u8 *afl_path = getenv("AFL_PATH");
|
|
||||||
u8 *slash, *tmp;
|
|
||||||
|
|
||||||
if (afl_path) {
|
|
||||||
|
|
||||||
tmp = alloc_printf("%s/afl-gcc-rt.o", afl_path);
|
|
||||||
|
|
||||||
if (!access(tmp, R_OK)) {
|
|
||||||
obj_path = afl_path;
|
|
||||||
ck_free(tmp);
|
|
||||||
return;
|
|
||||||
}
|
|
||||||
|
|
||||||
ck_free(tmp);
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
slash = strrchr(argv0, '/');
|
|
||||||
|
|
||||||
if (slash) {
|
|
||||||
|
|
||||||
u8 *dir;
|
|
||||||
|
|
||||||
*slash = 0;
|
|
||||||
dir = ck_strdup(argv0);
|
|
||||||
*slash = '/';
|
|
||||||
|
|
||||||
tmp = alloc_printf("%s/afl-gcc-rt.o", dir);
|
|
||||||
|
|
||||||
if (!access(tmp, R_OK)) {
|
|
||||||
obj_path = dir;
|
|
||||||
ck_free(tmp);
|
|
||||||
return;
|
|
||||||
}
|
|
||||||
|
|
||||||
ck_free(tmp);
|
|
||||||
ck_free(dir);
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
if (!access(AFL_PATH "/afl-gcc-rt.o", R_OK)) {
|
|
||||||
obj_path = AFL_PATH;
|
|
||||||
return;
|
|
||||||
}
|
|
||||||
|
|
||||||
FATAL("Unable to find 'afl-gcc-rt.o' or 'afl-gcc-pass.so'. Please set AFL_PATH");
|
|
||||||
}
|
|
||||||
|
|
||||||
|
|
||||||
/* Copy argv to cc_params, making the necessary edits. */
|
|
||||||
|
|
||||||
static void edit_params(u32 argc, char** argv) {
|
|
||||||
|
|
||||||
u8 fortify_set = 0, asan_set = 0, x_set = 0, maybe_linking = 1;
|
|
||||||
u8 *name;
|
|
||||||
|
|
||||||
cc_params = ck_alloc((argc + 64) * sizeof(u8*));
|
|
||||||
|
|
||||||
name = strrchr(argv[0], '/');
|
|
||||||
if (!name) name = argv[0]; else name++;
|
|
||||||
|
|
||||||
if (!strcmp(name, "afl-g++-fast")) {
|
|
||||||
u8* alt_cxx = getenv("AFL_CXX");
|
|
||||||
cc_params[0] = alt_cxx ? alt_cxx : (u8*)"g++";
|
|
||||||
} else {
|
|
||||||
u8* alt_cc = getenv("AFL_CC");
|
|
||||||
cc_params[0] = alt_cc ? alt_cc : (u8*)"gcc";
|
|
||||||
}
|
|
||||||
|
|
||||||
char* fplugin_arg = alloc_printf("-fplugin=%s/afl-gcc-pass.so", obj_path);
|
|
||||||
cc_params[cc_par_cnt++] = fplugin_arg;
|
|
||||||
|
|
||||||
while (--argc) {
|
|
||||||
u8* cur = *(++argv);
|
|
||||||
|
|
||||||
#if defined(__x86_64__)
|
|
||||||
if (!strcmp(cur, "-m32")) FATAL("-m32 is not supported");
|
|
||||||
#endif
|
|
||||||
|
|
||||||
if (!strcmp(cur, "-x")) x_set = 1;
|
|
||||||
|
|
||||||
if (!strcmp(cur, "-c") || !strcmp(cur, "-S") || !strcmp(cur, "-E") ||
|
|
||||||
!strcmp(cur, "-v")) maybe_linking = 0;
|
|
||||||
|
|
||||||
if (!strcmp(cur, "-fsanitize=address") ||
|
|
||||||
!strcmp(cur, "-fsanitize=memory")) asan_set = 1;
|
|
||||||
|
|
||||||
if (strstr(cur, "FORTIFY_SOURCE")) fortify_set = 1;
|
|
||||||
|
|
||||||
cc_params[cc_par_cnt++] = cur;
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
if (getenv("AFL_HARDEN")) {
|
|
||||||
|
|
||||||
cc_params[cc_par_cnt++] = "-fstack-protector-all";
|
|
||||||
|
|
||||||
if (!fortify_set)
|
|
||||||
cc_params[cc_par_cnt++] = "-D_FORTIFY_SOURCE=2";
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
if (!asan_set) {
|
|
||||||
|
|
||||||
if (getenv("AFL_USE_ASAN")) {
|
|
||||||
|
|
||||||
cc_params[cc_par_cnt++] = "-fsanitize=address";
|
|
||||||
|
|
||||||
if (getenv("AFL_USE_MSAN"))
|
|
||||||
FATAL("ASAN and MSAN are mutually exclusive");
|
|
||||||
|
|
||||||
} else if (getenv("AFL_USE_MSAN")) {
|
|
||||||
|
|
||||||
cc_params[cc_par_cnt++] = "-fsanitize=memory";
|
|
||||||
|
|
||||||
if (getenv("AFL_USE_ASAN"))
|
|
||||||
FATAL("ASAN and MSAN are mutually exclusive");
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
if (!getenv("AFL_DONT_OPTIMIZE")) {
|
|
||||||
|
|
||||||
cc_params[cc_par_cnt++] = "-g";
|
|
||||||
cc_params[cc_par_cnt++] = "-O3";
|
|
||||||
cc_params[cc_par_cnt++] = "-funroll-loops";
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
cc_params[cc_par_cnt++] = "-D__AFL_HAVE_MANUAL_CONTROL=1";
|
|
||||||
|
|
||||||
/* When the user tries to use persistent or deferred forkserver modes by
|
|
||||||
appending a single line to the program, we want to reliably inject a
|
|
||||||
signature into the binary (to be picked up by afl-fuzz) and we want
|
|
||||||
to call a function from the runtime .o file. This is unnecessarily
|
|
||||||
painful for three reasons:
|
|
||||||
|
|
||||||
1) We need to convince the compiler not to optimize out the signature.
|
|
||||||
This is done with __attribute__((used)).
|
|
||||||
|
|
||||||
2) We need to convince the linker, when called with -Wl,--gc-sections,
|
|
||||||
not to do the same. This is done by forcing an assignment to a
|
|
||||||
'volatile' pointer.
|
|
||||||
|
|
||||||
3) We need to declare __afl_persistent_loop() in the global namespace,
|
|
||||||
but doing this within a method in a class is hard - :: and extern "C"
|
|
||||||
are forbidden and __attribute__((alias(...))) doesn't work. Hence the
|
|
||||||
__asm__ aliasing trick.
|
|
||||||
|
|
||||||
*/
|
|
||||||
|
|
||||||
cc_params[cc_par_cnt++] = "-D__AFL_LOOP(_A)="
|
|
||||||
"({ static volatile char *_B __attribute__((used)); "
|
|
||||||
" _B = (char*)\"" PERSIST_SIG "\"; "
|
|
||||||
#ifdef __APPLE__
|
|
||||||
"int _L(unsigned int) __asm__(\"___afl_persistent_loop\"); "
|
|
||||||
#else
|
|
||||||
"int _L(unsigned int) __asm__(\"__afl_persistent_loop\"); "
|
|
||||||
#endif /* ^__APPLE__ */
|
|
||||||
"_L(_A); })";
|
|
||||||
|
|
||||||
cc_params[cc_par_cnt++] = "-D__AFL_INIT()="
|
|
||||||
"do { static volatile char *_A __attribute__((used)); "
|
|
||||||
" _A = (char*)\"" DEFER_SIG "\"; "
|
|
||||||
#ifdef __APPLE__
|
|
||||||
"void _I(void) __asm__(\"___afl_manual_init\"); "
|
|
||||||
#else
|
|
||||||
"void _I(void) __asm__(\"__afl_manual_init\"); "
|
|
||||||
#endif /* ^__APPLE__ */
|
|
||||||
"_I(); } while (0)";
|
|
||||||
|
|
||||||
if (maybe_linking) {
|
|
||||||
|
|
||||||
if (x_set) {
|
|
||||||
cc_params[cc_par_cnt++] = "-x";
|
|
||||||
cc_params[cc_par_cnt++] = "none";
|
|
||||||
}
|
|
||||||
|
|
||||||
cc_params[cc_par_cnt++] = alloc_printf("%s/afl-gcc-rt.o", obj_path);
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
cc_params[cc_par_cnt] = NULL;
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
|
|
||||||
/* Main entry point */
|
|
||||||
|
|
||||||
int main(int argc, char** argv) {
|
|
||||||
|
|
||||||
if (isatty(2) && !getenv("AFL_QUIET")) {
|
|
||||||
|
|
||||||
SAYF(cCYA "afl-gcc-fast" cRST " initial version 1.94 by <aseipp@pobox.com>, updated to " cBRI VERSION cRST " by <thorsten.schulz@uni-rostock.de>\n");
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
if (argc < 2) {
|
|
||||||
|
|
||||||
SAYF("\n"
|
|
||||||
"This is a helper application for afl-fuzz. It serves as a drop-in replacement\n"
|
|
||||||
"for gcc, letting you recompile third-party code with the required runtime\n"
|
|
||||||
"instrumentation. A common use pattern would be one of the following:\n\n"
|
|
||||||
|
|
||||||
" CC=%s/afl-gcc-fast ./configure\n"
|
|
||||||
" CXX=%s/afl-g++-fast ./configure\n\n"
|
|
||||||
|
|
||||||
"In contrast to the traditional afl-gcc tool, this version is implemented as\n"
|
|
||||||
"a GCC plugin and tends to offer improved performance with slow programs\n"
|
|
||||||
"(similarly to the LLVM plugin used by afl-clang-fast).\n\n"
|
|
||||||
|
|
||||||
"You can specify custom next-stage toolchain via AFL_CC and AFL_CXX. Setting\n"
|
|
||||||
"AFL_HARDEN enables hardening optimizations in the compiled code.\n\n",
|
|
||||||
BIN_PATH, BIN_PATH);
|
|
||||||
|
|
||||||
exit(1);
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
|
|
||||||
find_obj(argv[0]);
|
|
||||||
|
|
||||||
edit_params(argc, argv);
|
|
||||||
/*if (isatty(2) && !getenv("AFL_QUIET")) {
|
|
||||||
printf("Calling \"%s\" with:\n", cc_params[0]);
|
|
||||||
for(int i=1; i<cc_par_cnt; i++) printf("%s\n", cc_params[i]);
|
|
||||||
}
|
|
||||||
*/
|
|
||||||
execvp(cc_params[0], (char**)cc_params);
|
|
||||||
|
|
||||||
FATAL("Oops, failed to execute '%s' - check your PATH", cc_params[0]);
|
|
||||||
|
|
||||||
return 0;
|
|
||||||
|
|
||||||
}
|
|
||||||
@ -1,377 +0,0 @@
|
|||||||
//
|
|
||||||
// There are some TODOs in this file:
|
|
||||||
// - dont instrument blocks that are uninterested
|
|
||||||
// - implement whitelist feature
|
|
||||||
// - implement notZero
|
|
||||||
// - fix crash
|
|
||||||
//
|
|
||||||
|
|
||||||
/*
|
|
||||||
american fuzzy lop - GCC instrumentation pass
|
|
||||||
---------------------------------------------
|
|
||||||
|
|
||||||
Written by Austin Seipp <aseipp@pobox.com> with bits from
|
|
||||||
Emese Revfy <re.emese@gmail.com>
|
|
||||||
|
|
||||||
Updated by Thorsten Schulz <thorsten.schulz@uni-rostock.de>
|
|
||||||
|
|
||||||
GCC integration design is based on the LLVM design, which comes
|
|
||||||
from Laszlo Szekeres. Some of the boilerplate code below for
|
|
||||||
afl_pass to adapt to different GCC versions was taken from Emese
|
|
||||||
Revfy's Size Overflow plugin for GCC, licensed under the GPLv2/v3.
|
|
||||||
|
|
||||||
(NOTE: this plugin code is under GPLv3, in order to comply with the
|
|
||||||
GCC runtime library exception, which states that you may distribute
|
|
||||||
"Target Code" from the compiler under a license of your choice, as
|
|
||||||
long as the "Compilation Process" is "Eligible", and contains no
|
|
||||||
GPL-incompatible software in GCC "during the process of
|
|
||||||
transforming high level code to target code". In this case, the
|
|
||||||
plugin will be used to generate "Target Code" during the
|
|
||||||
"Compilation Process", and thus it must be GPLv3 to be "eligible".)
|
|
||||||
|
|
||||||
Copyright (C) 2015 Austin Seipp
|
|
||||||
|
|
||||||
This program is free software: you can redistribute it and/or modify
|
|
||||||
it under the terms of the GNU General Public License as published by
|
|
||||||
the Free Software Foundation, either version 3 of the License, or
|
|
||||||
(at your option) any later version.
|
|
||||||
|
|
||||||
This program is distributed in the hope that it will be useful,
|
|
||||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
||||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
||||||
GNU General Public License for more details.
|
|
||||||
|
|
||||||
You should have received a copy of the GNU General Public License
|
|
||||||
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
||||||
|
|
||||||
*/
|
|
||||||
|
|
||||||
//#define BUILD_INLINE_INST
|
|
||||||
|
|
||||||
#include "../config.h"
|
|
||||||
#include "../debug.h"
|
|
||||||
|
|
||||||
/* clear helper AFL types pulls in, which intervene with gcc-plugin geaders from GCC-8 */
|
|
||||||
#ifdef likely
|
|
||||||
#undef likely
|
|
||||||
#endif
|
|
||||||
#ifdef unlikely
|
|
||||||
#undef unlikely
|
|
||||||
#endif
|
|
||||||
|
|
||||||
|
|
||||||
#include <stdio.h>
|
|
||||||
#include <stdlib.h>
|
|
||||||
#include <unistd.h>
|
|
||||||
|
|
||||||
#include <gcc-plugin.h>
|
|
||||||
#include <plugin-version.h>
|
|
||||||
#include <diagnostic.h>
|
|
||||||
#include <tree.h>
|
|
||||||
#include <tree-ssa.h>
|
|
||||||
#include <tree-pass.h>
|
|
||||||
#include <tree-ssa-alias.h>
|
|
||||||
#include <basic-block.h>
|
|
||||||
#include <gimple-expr.h>
|
|
||||||
#include <gimple.h>
|
|
||||||
#include <gimple-iterator.h>
|
|
||||||
#include <version.h>
|
|
||||||
#include <toplev.h>
|
|
||||||
#include <intl.h>
|
|
||||||
#include <context.h>
|
|
||||||
#include <stringpool.h>
|
|
||||||
#include <cgraph.h>
|
|
||||||
#include <cfgloop.h>
|
|
||||||
|
|
||||||
/* -------------------------------------------------------------------------- */
|
|
||||||
/* -- AFL instrumentation pass ---------------------------------------------- */
|
|
||||||
|
|
||||||
static int be_quiet = 0;
|
|
||||||
static unsigned int inst_ratio = 100;
|
|
||||||
static bool inst_ext = true; /* I reckon inline is broken / unfunctional */
|
|
||||||
|
|
||||||
|
|
||||||
static unsigned int ext_call_instrument(function *fun) {
|
|
||||||
/* Instrument all the things! */
|
|
||||||
basic_block bb;
|
|
||||||
unsigned finst_blocks = 0;
|
|
||||||
unsigned fcnt_blocks = 0;
|
|
||||||
|
|
||||||
FOR_ALL_BB_FN(bb, fun) {
|
|
||||||
gimple_seq fcall;
|
|
||||||
gimple_seq seq = NULL;
|
|
||||||
gimple_stmt_iterator bentry;
|
|
||||||
|
|
||||||
if (!fcnt_blocks++) continue; /* skip block 0 */
|
|
||||||
|
|
||||||
// TODO: if the predecessor does not have ast least two destinations
|
|
||||||
// then skip this block :TODO
|
|
||||||
|
|
||||||
/* Bail on this block if we trip the specified ratio */
|
|
||||||
if (R(100) >= inst_ratio) continue;
|
|
||||||
|
|
||||||
/* Make up cur_loc */
|
|
||||||
|
|
||||||
unsigned int rand_loc = R(MAP_SIZE);
|
|
||||||
tree cur_loc = build_int_cst(uint64_type_node, rand_loc);
|
|
||||||
|
|
||||||
/* Update bitmap via external call */
|
|
||||||
/* to quote:
|
|
||||||
* /+ Trace a basic block with some ID +/
|
|
||||||
* void __afl_trace(u16 x);
|
|
||||||
*/
|
|
||||||
|
|
||||||
tree fntype = build_function_type_list(
|
|
||||||
void_type_node, /* return */
|
|
||||||
uint16_type_node, /* args */
|
|
||||||
NULL_TREE); /* done */
|
|
||||||
tree fndecl = build_fn_decl("__afl_trace", fntype);
|
|
||||||
TREE_STATIC(fndecl) = 1; /* Defined elsewhere */
|
|
||||||
TREE_PUBLIC(fndecl) = 1; /* Public */
|
|
||||||
DECL_EXTERNAL(fndecl) = 1; /* External linkage */
|
|
||||||
DECL_ARTIFICIAL(fndecl) = 1; /* Injected by compiler */
|
|
||||||
|
|
||||||
fcall = gimple_build_call(fndecl, 1, cur_loc); /* generate the function _call_ to above built reference, with *1* parameter -> the random const for the location */
|
|
||||||
gimple_seq_add_stmt(&seq, fcall); /* and insert into a sequence */
|
|
||||||
|
|
||||||
/* Done - grab the entry to the block and insert sequence */
|
|
||||||
bentry = gsi_start_bb(bb);
|
|
||||||
gsi_insert_seq_before(&bentry, seq, GSI_SAME_STMT);
|
|
||||||
|
|
||||||
finst_blocks++;
|
|
||||||
}
|
|
||||||
fcnt_blocks--; /* discard the first in the count */
|
|
||||||
|
|
||||||
/* Say something nice. */
|
|
||||||
if (!be_quiet) {
|
|
||||||
if (!finst_blocks)
|
|
||||||
WARNF(G_("No instrumentation targets found in " cBRI "%s" cRST ),
|
|
||||||
function_name(fun));
|
|
||||||
else if (finst_blocks < fcnt_blocks)
|
|
||||||
OKF(G_("Instrumented %2u /%2u locations in " cBRI "%s" cRST ),
|
|
||||||
finst_blocks, fcnt_blocks,
|
|
||||||
function_name(fun));
|
|
||||||
else
|
|
||||||
OKF(G_("Instrumented %2u locations in " cBRI "%s" cRST ),
|
|
||||||
finst_blocks,
|
|
||||||
function_name(fun));
|
|
||||||
}
|
|
||||||
|
|
||||||
return 0;
|
|
||||||
}
|
|
||||||
|
|
||||||
static unsigned int inline_instrument(function *fun) {
|
|
||||||
#ifdef BUILD_INLINE_INST /* ifdef inline away, so I don't have to refactor it */
|
|
||||||
/* Instrument all the things! */
|
|
||||||
basic_block bb;
|
|
||||||
unsigned finst_blocks = 0;
|
|
||||||
unsigned fcnt_blocks = 0;
|
|
||||||
|
|
||||||
/* Set up global type declarations */
|
|
||||||
tree map_type = build_pointer_type(unsigned_char_type_node);
|
|
||||||
tree map_ptr_g = build_decl(UNKNOWN_LOCATION, VAR_DECL, get_identifier_with_length("__afl_area_ptr",14), map_type);
|
|
||||||
TREE_USED(map_ptr_g) = 1;
|
|
||||||
TREE_STATIC(map_ptr_g) = 1; /* Defined elsewhere */
|
|
||||||
DECL_EXTERNAL(map_ptr_g) = 1; /* External linkage */
|
|
||||||
DECL_PRESERVE_P(map_ptr_g) = 1;
|
|
||||||
DECL_ARTIFICIAL(map_ptr_g) = 1;
|
|
||||||
rest_of_decl_compilation(map_ptr_g, 1, 0);
|
|
||||||
|
|
||||||
tree prev_loc_g = build_decl(UNKNOWN_LOCATION, VAR_DECL, get_identifier_with_length("__afl_prev_loc",14), uint16_type_node);
|
|
||||||
TREE_USED(prev_loc_g) = 1;
|
|
||||||
TREE_STATIC(prev_loc_g) = 1; /* Defined elsewhere */
|
|
||||||
DECL_EXTERNAL(prev_loc_g) = 1; /* External linkage */
|
|
||||||
DECL_PRESERVE_P(prev_loc_g) = 1;
|
|
||||||
DECL_ARTIFICIAL(prev_loc_g) = 1;
|
|
||||||
rest_of_decl_compilation(prev_loc_g, 1, 0);
|
|
||||||
|
|
||||||
FOR_ALL_BB_FN(bb, fun) {
|
|
||||||
gimple *g;
|
|
||||||
gimple_seq seq = NULL;
|
|
||||||
gimple_stmt_iterator bentry;
|
|
||||||
|
|
||||||
if (!fcnt_blocks++) continue; /* skip block 0 */
|
|
||||||
|
|
||||||
/* Bail on this block if we trip the specified ratio */
|
|
||||||
if (R(100) >= inst_ratio) continue;
|
|
||||||
|
|
||||||
/* Make up cur_loc */
|
|
||||||
|
|
||||||
unsigned int rand_loc = R(MAP_SIZE);
|
|
||||||
tree cur_loc = build_int_cst(uint64_type_node, rand_loc);
|
|
||||||
|
|
||||||
/* Load prev_loc, xor with cur_loc */
|
|
||||||
|
|
||||||
tree area_off = create_tmp_var(uint64_type_node, "area_off");
|
|
||||||
g = gimple_build_assign(area_off, BIT_XOR_EXPR, prev_loc_g, cur_loc);
|
|
||||||
gimple_seq_add_stmt(&seq, g); // area_off = prev_loc ^ cur_loc
|
|
||||||
|
|
||||||
/* Update bitmap */
|
|
||||||
|
|
||||||
// tree zero = build_int_cst(unsigned_char_type_node, 0);
|
|
||||||
tree one = build_int_cst(unsigned_char_type_node, 1);
|
|
||||||
|
|
||||||
tree tmp1 = create_tmp_var(map_type, "tmp1");
|
|
||||||
g = gimple_build_assign(tmp1, PLUS_EXPR, map_ptr_g, area_off);
|
|
||||||
gimple_seq_add_stmt(&seq, g); // tmp1 = __afl_area_ptr + area_off
|
|
||||||
SAYF(G_("%d,"), fcnt_blocks);
|
|
||||||
|
|
||||||
tree tmp2 = create_tmp_var(unsigned_char_type_node, "tmp2");
|
|
||||||
//tree tmp1_ptr = build_simple_mem_ref_loc(UNKNOWN_LOCATION, tmp1);
|
|
||||||
g = gimple_build_assign(tmp2, INDIRECT_REF, tmp1);
|
|
||||||
gimple_seq_add_stmt(&seq, g); // tmp2 = *tmp1
|
|
||||||
|
|
||||||
tree tmp3 = create_tmp_var(unsigned_char_type_node, "tmp3");
|
|
||||||
g = gimple_build_assign(tmp3, PLUS_EXPR, tmp2, one);
|
|
||||||
gimple_seq_add_stmt(&seq, g); // tmp3 = tmp2 + 1
|
|
||||||
|
|
||||||
// TODO: neverZero: here we have to check if tmp3 == 0
|
|
||||||
// and add 1 if so
|
|
||||||
|
|
||||||
// tree tmp4 = create_tmp_var(map_type, "tmp4");
|
|
||||||
// g = gimple_build_assign(tmp4, PLUS_EXPR, map_ptr_g, area_off);
|
|
||||||
// gimple_seq_add_stmt(&seq, g); // tmp4 = __afl_area_ptr + area_off
|
|
||||||
|
|
||||||
// tree deref2 = build2(MEM_REF, map_type, tmp4, zero);
|
|
||||||
tree deref2 = build4(ARRAY_REF, map_type, map_ptr_g, area_off, NULL, NULL);
|
|
||||||
g = gimple_build_assign(deref2, MODIFY_EXPR, tmp3);
|
|
||||||
gimple_seq_add_stmt(&seq, g); // *tmp4 = tmp3
|
|
||||||
SAYF(G_("+%d,"), fcnt_blocks);
|
|
||||||
|
|
||||||
/* Set prev_loc to cur_loc >> 1 */
|
|
||||||
|
|
||||||
tree shifted_loc = build_int_cst(TREE_TYPE(prev_loc_g), rand_loc >> 1);
|
|
||||||
g = gimple_build_assign(prev_loc_g, MODIFY_EXPR, shifted_loc);
|
|
||||||
gimple_seq_add_stmt(&seq, g); // __afl_pred_loc = cur_loc >> 1
|
|
||||||
|
|
||||||
/* Done - grab the entry to the block and insert sequence */
|
|
||||||
|
|
||||||
bentry = gsi_start_bb(bb);
|
|
||||||
gsi_insert_seq_before(&bentry, seq, GSI_SAME_STMT);
|
|
||||||
|
|
||||||
inst_blocks++;
|
|
||||||
finst_blocks++;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Say something nice. */
|
|
||||||
if (!be_quiet) {
|
|
||||||
if (!finst_blocks)
|
|
||||||
WARNF(G_("No instrumentation targets found in " cBRI "%s" cRST ),
|
|
||||||
function_name(fun));
|
|
||||||
else if (finst_blocks < fcnt_blocks)
|
|
||||||
OKF(G_("Instrumented %2u /%2u locations in " cBRI "%s" cRST ),
|
|
||||||
finst_blocks, fcnt_blocks,
|
|
||||||
function_name(fun));
|
|
||||||
else
|
|
||||||
OKF(G_("Instrumented %2u locations in " cBRI "%s" cRST ),
|
|
||||||
finst_blocks,
|
|
||||||
function_name(fun));
|
|
||||||
}
|
|
||||||
|
|
||||||
#endif
|
|
||||||
return 0;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* -------------------------------------------------------------------------- */
|
|
||||||
/* -- Boilerplate and initialization ---------------------------------------- */
|
|
||||||
|
|
||||||
static const struct pass_data afl_pass_data = {
|
|
||||||
|
|
||||||
.type = GIMPLE_PASS,
|
|
||||||
.name = "afl-inst",
|
|
||||||
.optinfo_flags = OPTGROUP_NONE,
|
|
||||||
|
|
||||||
.tv_id = TV_NONE,
|
|
||||||
.properties_required = 0,
|
|
||||||
.properties_provided = 0,
|
|
||||||
.properties_destroyed = 0,
|
|
||||||
.todo_flags_start = 0,
|
|
||||||
// NOTE(aseipp): it's very, very important to include
|
|
||||||
// at least 'TODO_update_ssa' here so that GCC will
|
|
||||||
// properly update the resulting SSA form, e.g., to
|
|
||||||
// include new PHI nodes for newly added symbols or
|
|
||||||
// names. Do not remove this. Do not taunt Happy Fun
|
|
||||||
// Ball.
|
|
||||||
.todo_flags_finish = TODO_update_ssa | TODO_verify_il | TODO_cleanup_cfg,
|
|
||||||
};
|
|
||||||
|
|
||||||
namespace {
|
|
||||||
|
|
||||||
class afl_pass : public gimple_opt_pass {
|
|
||||||
private:
|
|
||||||
bool do_ext_call;
|
|
||||||
|
|
||||||
public:
|
|
||||||
afl_pass(bool ext_call, gcc::context *g) : gimple_opt_pass(afl_pass_data, g), do_ext_call(ext_call) {}
|
|
||||||
|
|
||||||
virtual unsigned int execute(function *fun) {
|
|
||||||
// TODO: implement whitelist feature here :TODO
|
|
||||||
return do_ext_call ? ext_call_instrument(fun) : inline_instrument(fun);
|
|
||||||
}
|
|
||||||
}; /* class afl_pass */
|
|
||||||
|
|
||||||
} /* anon namespace */
|
|
||||||
|
|
||||||
static struct opt_pass *make_afl_pass(bool ext_call, gcc::context *ctxt) {
|
|
||||||
return new afl_pass(ext_call, ctxt);
|
|
||||||
}
|
|
||||||
|
|
||||||
/* -------------------------------------------------------------------------- */
|
|
||||||
/* -- Initialization -------------------------------------------------------- */
|
|
||||||
|
|
||||||
int plugin_is_GPL_compatible = 1;
|
|
||||||
|
|
||||||
static struct plugin_info afl_plugin_info = {
|
|
||||||
.version = "20181200",
|
|
||||||
.help = "AFL gcc plugin\n",
|
|
||||||
};
|
|
||||||
|
|
||||||
int plugin_init(struct plugin_name_args *plugin_info,
|
|
||||||
struct plugin_gcc_version *version) {
|
|
||||||
|
|
||||||
struct register_pass_info afl_pass_info;
|
|
||||||
struct timeval tv;
|
|
||||||
struct timezone tz;
|
|
||||||
u32 rand_seed;
|
|
||||||
|
|
||||||
/* Setup random() so we get Actually Random(TM) outputs from R() */
|
|
||||||
gettimeofday(&tv, &tz);
|
|
||||||
rand_seed = tv.tv_sec ^ tv.tv_usec ^ getpid();
|
|
||||||
srandom(rand_seed);
|
|
||||||
|
|
||||||
/* Pass information */
|
|
||||||
afl_pass_info.pass = make_afl_pass(inst_ext, g);
|
|
||||||
afl_pass_info.reference_pass_name = "ssa";
|
|
||||||
afl_pass_info.ref_pass_instance_number = 1;
|
|
||||||
afl_pass_info.pos_op = PASS_POS_INSERT_AFTER;
|
|
||||||
|
|
||||||
if (!plugin_default_version_check(version, &gcc_version)) {
|
|
||||||
FATAL(G_("Incompatible gcc/plugin versions!"));
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Show a banner */
|
|
||||||
if (isatty(2) && !getenv("AFL_QUIET")) {
|
|
||||||
SAYF(G_(cCYA "afl-gcc-pass" cRST " initial version 1.94 by <aseipp@pobox.com>, updated to " cBRI VERSION cRST " by <thorsten.schulz@uni-rostock.de>\n"));
|
|
||||||
} else
|
|
||||||
be_quiet = 1;
|
|
||||||
|
|
||||||
/* Decide instrumentation ratio */
|
|
||||||
char* inst_ratio_str = getenv("AFL_INST_RATIO");
|
|
||||||
|
|
||||||
if (inst_ratio_str) {
|
|
||||||
if (sscanf(inst_ratio_str, "%u", &inst_ratio) != 1 || !inst_ratio || inst_ratio > 100)
|
|
||||||
FATAL(G_("Bad value of AFL_INST_RATIO (must be between 1 and 100)"));
|
|
||||||
else {
|
|
||||||
if (!be_quiet)
|
|
||||||
ACTF(G_("%s instrumentation at ratio of %u%% in %s mode."),
|
|
||||||
inst_ext ? G_("Call-based") : G_("Inline"),
|
|
||||||
inst_ratio,
|
|
||||||
getenv("AFL_HARDEN") ? G_("hardened") : G_("non-hardened"));
|
|
||||||
}
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Go go gadget */
|
|
||||||
register_callback(plugin_info->base_name, PLUGIN_INFO, NULL, &afl_plugin_info);
|
|
||||||
register_callback(plugin_info->base_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &afl_pass_info);
|
|
||||||
return 0;
|
|
||||||
}
|
|
||||||
@ -1,224 +0,0 @@
|
|||||||
/*
|
|
||||||
american fuzzy lop - GCC plugin instrumentation bootstrap
|
|
||||||
---------------------------------------------------------
|
|
||||||
|
|
||||||
Written by Austin Seipp <aseipp@pobox.com> and
|
|
||||||
Laszlo Szekeres <lszekeres@google.com> and
|
|
||||||
Michal Zalewski <lcamtuf@google.com>
|
|
||||||
|
|
||||||
GCC integration design is based on the LLVM design, which comes
|
|
||||||
from Laszlo Szekeres.
|
|
||||||
|
|
||||||
Copyright 2015 Google Inc. All rights reserved.
|
|
||||||
|
|
||||||
Licensed under the Apache License, Version 2.0 (the "License");
|
|
||||||
you may not use this file except in compliance with the License.
|
|
||||||
You may obtain a copy of the License at:
|
|
||||||
|
|
||||||
http://www.apache.org/licenses/LICENSE-2.0
|
|
||||||
|
|
||||||
This code is the rewrite of afl-as.h's main_payload.
|
|
||||||
|
|
||||||
*/
|
|
||||||
|
|
||||||
#include "../config.h"
|
|
||||||
#include "../types.h"
|
|
||||||
|
|
||||||
#include <stdlib.h>
|
|
||||||
#include <signal.h>
|
|
||||||
#include <unistd.h>
|
|
||||||
#include <assert.h>
|
|
||||||
|
|
||||||
#include <sys/mman.h>
|
|
||||||
#include <sys/shm.h>
|
|
||||||
#include <sys/wait.h>
|
|
||||||
#include <sys/types.h>
|
|
||||||
|
|
||||||
|
|
||||||
/* Globals needed by the injected instrumentation. The __afl_area_initial region
|
|
||||||
is used for instrumentation output before __afl_map_shm() has a chance to run.
|
|
||||||
It will end up as .comm, so it shouldn't be too wasteful. */
|
|
||||||
|
|
||||||
u8 __afl_area_initial[MAP_SIZE];
|
|
||||||
u8* __afl_area_ptr = __afl_area_initial;
|
|
||||||
u16 __afl_prev_loc;
|
|
||||||
|
|
||||||
|
|
||||||
/* Running in persistent mode? */
|
|
||||||
|
|
||||||
static u8 is_persistent;
|
|
||||||
|
|
||||||
/* Trace a basic block with some ID */
|
|
||||||
void __afl_trace(u16 x) {
|
|
||||||
u16 l = __afl_prev_loc;
|
|
||||||
u16 n = l ^ x;
|
|
||||||
*(__afl_area_ptr+n) += 1;
|
|
||||||
__afl_prev_loc = (x >> 1);
|
|
||||||
return;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* SHM setup. */
|
|
||||||
|
|
||||||
static void __afl_map_shm(void) {
|
|
||||||
|
|
||||||
u8 *id_str = getenv(SHM_ENV_VAR);
|
|
||||||
|
|
||||||
/* If we're running under AFL, attach to the appropriate region, replacing the
|
|
||||||
early-stage __afl_area_initial region that is needed to allow some really
|
|
||||||
hacky .init code to work correctly in projects such as OpenSSL. */
|
|
||||||
|
|
||||||
if (id_str) {
|
|
||||||
|
|
||||||
u32 shm_id = atoi(id_str);
|
|
||||||
|
|
||||||
__afl_area_ptr = shmat(shm_id, NULL, 0);
|
|
||||||
|
|
||||||
/* Whooooops. */
|
|
||||||
|
|
||||||
if (__afl_area_ptr == (void *)-1) exit(1);
|
|
||||||
|
|
||||||
/* Write something into the bitmap so that even with low AFL_INST_RATIO,
|
|
||||||
our parent doesn't give up on us. */
|
|
||||||
|
|
||||||
__afl_area_ptr[0] = 1;
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
|
|
||||||
/* Fork server logic. */
|
|
||||||
|
|
||||||
static void __afl_start_forkserver(void) {
|
|
||||||
|
|
||||||
static u8 tmp[4];
|
|
||||||
s32 child_pid;
|
|
||||||
|
|
||||||
u8 child_stopped = 0;
|
|
||||||
|
|
||||||
/* Phone home and tell the parent that we're OK. If parent isn't there,
|
|
||||||
assume we're not running in forkserver mode and just execute program. */
|
|
||||||
|
|
||||||
if (write(FORKSRV_FD + 1, tmp, 4) != 4) return;
|
|
||||||
|
|
||||||
while (1) {
|
|
||||||
|
|
||||||
u32 was_killed;
|
|
||||||
int status;
|
|
||||||
|
|
||||||
/* Wait for parent by reading from the pipe. Abort if read fails. */
|
|
||||||
|
|
||||||
if (read(FORKSRV_FD, &was_killed, 4) != 4) exit(1);
|
|
||||||
|
|
||||||
/* If we stopped the child in persistent mode, but there was a race
|
|
||||||
condition and afl-fuzz already issued SIGKILL, write off the old
|
|
||||||
process. */
|
|
||||||
|
|
||||||
if (child_stopped && was_killed) {
|
|
||||||
child_stopped = 0;
|
|
||||||
if (waitpid(child_pid, &status, 0) < 0) exit(1);
|
|
||||||
}
|
|
||||||
|
|
||||||
if (!child_stopped) {
|
|
||||||
|
|
||||||
/* Once woken up, create a clone of our process. */
|
|
||||||
|
|
||||||
child_pid = fork();
|
|
||||||
if (child_pid < 0) exit(1);
|
|
||||||
|
|
||||||
/* In child process: close fds, resume execution. */
|
|
||||||
|
|
||||||
if (!child_pid) {
|
|
||||||
|
|
||||||
close(FORKSRV_FD);
|
|
||||||
close(FORKSRV_FD + 1);
|
|
||||||
return;
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
} else {
|
|
||||||
|
|
||||||
/* Special handling for persistent mode: if the child is alive but
|
|
||||||
currently stopped, simply restart it with SIGCONT. */
|
|
||||||
|
|
||||||
kill(child_pid, SIGCONT);
|
|
||||||
child_stopped = 0;
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
/* In parent process: write PID to pipe, then wait for child. */
|
|
||||||
|
|
||||||
if (write(FORKSRV_FD + 1, &child_pid, 4) != 4) exit(1);
|
|
||||||
|
|
||||||
if (waitpid(child_pid, &status, is_persistent ? WUNTRACED : 0) < 0)
|
|
||||||
exit(1);
|
|
||||||
|
|
||||||
/* In persistent mode, the child stops itself with SIGSTOP to indicate
|
|
||||||
a successful run. In this case, we want to wake it up without forking
|
|
||||||
again. */
|
|
||||||
|
|
||||||
if (WIFSTOPPED(status)) child_stopped = 1;
|
|
||||||
|
|
||||||
/* Relay wait status to pipe, then loop back. */
|
|
||||||
|
|
||||||
if (write(FORKSRV_FD + 1, &status, 4) != 4) exit(1);
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
|
|
||||||
/* A simplified persistent mode handler, used as explained in README.llvm. */
|
|
||||||
|
|
||||||
int __afl_persistent_loop(unsigned int max_cnt) {
|
|
||||||
|
|
||||||
static u8 first_pass = 1;
|
|
||||||
static u32 cycle_cnt;
|
|
||||||
|
|
||||||
if (first_pass) {
|
|
||||||
|
|
||||||
cycle_cnt = max_cnt;
|
|
||||||
first_pass = 0;
|
|
||||||
return 1;
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
if (is_persistent && --cycle_cnt) {
|
|
||||||
|
|
||||||
raise(SIGSTOP);
|
|
||||||
return 1;
|
|
||||||
|
|
||||||
} else return 0;
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
|
|
||||||
/* This one can be called from user code when deferred forkserver mode
|
|
||||||
is enabled. */
|
|
||||||
|
|
||||||
void __afl_manual_init(void) {
|
|
||||||
|
|
||||||
static u8 init_done;
|
|
||||||
|
|
||||||
if (!init_done) {
|
|
||||||
|
|
||||||
__afl_map_shm();
|
|
||||||
__afl_start_forkserver();
|
|
||||||
init_done = 1;
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
}
|
|
||||||
|
|
||||||
|
|
||||||
/* Proper initialization routine. */
|
|
||||||
|
|
||||||
__attribute__((constructor(101))) void __afl_auto_init(void) {
|
|
||||||
|
|
||||||
is_persistent = !!getenv(PERSIST_ENV_VAR);
|
|
||||||
|
|
||||||
if (getenv(DEFER_ENV_VAR)) return;
|
|
||||||
|
|
||||||
__afl_manual_init();
|
|
||||||
|
|
||||||
}
|
|
||||||
Reference in New Issue
Block a user