Index: third_party/afl/src/llvm_mode/afl-clang-fast.c |
diff --git a/third_party/afl/src/llvm_mode/afl-clang-fast.c b/third_party/afl/src/llvm_mode/afl-clang-fast.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..b9cedea954ad3d26d259f2b7b054d7f7d793ea07 |
--- /dev/null |
+++ b/third_party/afl/src/llvm_mode/afl-clang-fast.c |
@@ -0,0 +1,327 @@ |
+/* |
+ american fuzzy lop - LLVM-mode wrapper for clang |
+ ------------------------------------------------ |
+ |
+ Written by Laszlo Szekeres <lszekeres@google.com> and |
+ Michal Zalewski <lcamtuf@google.com> |
+ |
+ LLVM integration design comes from Laszlo Szekeres. |
+ |
+ Copyright 2015, 2016 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 clang, similar in most respects |
+ to ../afl-gcc. 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-llvm-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-llvm-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-llvm-rt.o", R_OK)) { |
+ obj_path = AFL_PATH; |
+ return; |
+ } |
+ |
+ FATAL("Unable to find 'afl-llvm-rt.o' or 'afl-llvm-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, bit_mode = 0; |
+ 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-clang-fast++")) { |
+ u8* alt_cxx = getenv("AFL_CXX"); |
+ cc_params[0] = alt_cxx ? alt_cxx : (u8*)"clang++"; |
+ } else { |
+ u8* alt_cc = getenv("AFL_CC"); |
+ cc_params[0] = alt_cc ? alt_cc : (u8*)"clang"; |
+ } |
+ |
+ /* There are two ways to compile afl-clang-fast. In the traditional mode, we |
+ use afl-llvm-pass.so to inject instrumentation. In the experimental |
+ 'trace-pc' mode, we use native LLVM instrumentation callbacks instead. |
+ The latter is a very recent addition - see: |
+ |
+ http://clang.llvm.org/docs/SanitizerCoverage.html#tracing-pcs */ |
+ |
+#ifdef USE_TRACE_PC |
+ cc_params[cc_par_cnt++] = "-fsanitize-coverage=bb,trace-pc"; |
+#else |
+ cc_params[cc_par_cnt++] = "-Xclang"; |
+ cc_params[cc_par_cnt++] = "-load"; |
+ cc_params[cc_par_cnt++] = "-Xclang"; |
+ cc_params[cc_par_cnt++] = alloc_printf("%s/afl-llvm-pass.so", obj_path); |
+#endif /* ^USE_TRACE_PC */ |
+ |
+ cc_params[cc_par_cnt++] = "-Qunused-arguments"; |
+ |
+ while (--argc) { |
+ u8* cur = *(++argv); |
+ |
+ if (!strcmp(cur, "-m32")) bit_mode = 32; |
+ if (!strcmp(cur, "-m64")) bit_mode = 64; |
+ |
+ 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; |
+ |
+ if (!strcmp(cur, "-shared")) maybe_linking = 0; |
+ |
+ 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"); |
+ |
+ } |
+ |
+ } |
+ |
+#ifdef USE_TRACE_PC |
+ |
+ if (getenv("AFL_INST_RATIO")) |
+ FATAL("AFL_INST_RATIO not available at compile time with 'trace-pc'."); |
+ |
+#endif /* USE_TRACE_PC */ |
+ |
+ 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"; |
+ cc_params[cc_par_cnt++] = "-D__AFL_COMPILER=1"; |
+ cc_params[cc_par_cnt++] = "-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION=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__ |
+ "__attribute__((visibility(\"default\"))) " |
+ "int _L(unsigned int) __asm__(\"___afl_persistent_loop\"); " |
+#else |
+ "__attribute__((visibility(\"default\"))) " |
+ "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__ |
+ "__attribute__((visibility(\"default\"))) " |
+ "void _I(void) __asm__(\"___afl_manual_init\"); " |
+#else |
+ "__attribute__((visibility(\"default\"))) " |
+ "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"; |
+ } |
+ |
+ switch (bit_mode) { |
+ |
+ case 0: |
+ cc_params[cc_par_cnt++] = alloc_printf("%s/afl-llvm-rt.o", obj_path); |
+ break; |
+ |
+ case 32: |
+ cc_params[cc_par_cnt++] = alloc_printf("%s/afl-llvm-rt-32.o", obj_path); |
+ |
+ if (access(cc_params[cc_par_cnt - 1], R_OK)) |
+ FATAL("-m32 is not supported by your compiler"); |
+ |
+ break; |
+ |
+ case 64: |
+ cc_params[cc_par_cnt++] = alloc_printf("%s/afl-llvm-rt-64.o", obj_path); |
+ |
+ if (access(cc_params[cc_par_cnt - 1], R_OK)) |
+ FATAL("-m64 is not supported by your compiler"); |
+ |
+ break; |
+ |
+ } |
+ |
+ } |
+ |
+ cc_params[cc_par_cnt] = NULL; |
+ |
+} |
+ |
+ |
+/* Main entry point */ |
+ |
+int main(int argc, char** argv) { |
+ |
+ if (isatty(2) && !getenv("AFL_QUIET")) { |
+ |
+ SAYF(cCYA "afl-clang-fast " cBRI VERSION cRST " by <lszekeres@google.com>\n"); |
+ |
+ } |
+ |
+ if (argc < 2) { |
+ |
+ SAYF("\n" |
+ "This is a helper application for afl-fuzz. It serves as a drop-in replacement\n" |
+ "for clang, 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-clang-fast ./configure\n" |
+ " CXX=%s/afl-clang-fast++ ./configure\n\n" |
+ |
+ "In contrast to the traditional afl-clang tool, this version is implemented as\n" |
+ "an LLVM pass and tends to offer improved performance with slow programs.\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); |
+ |
+ execvp(cc_params[0], (char**)cc_params); |
+ |
+ FATAL("Oops, failed to execute '%s' - check your PATH", cc_params[0]); |
+ |
+ return 0; |
+ |
+} |