/* american fuzzy lop++ - LLVM-mode wrapper for clang ------------------------------------------------ Written by Laszlo Szekeres and Michal Zalewski LLVM integration design comes from Laszlo Szekeres. Copyright 2015, 2016 Google Inc. All rights reserved. Copyright 2019-2020 AFLplusplus Project. 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 "common.h" #include "config.h" #include "types.h" #include "debug.h" #include "alloc-inl.h" #include "llvm-ngram-coverage.h" #include #include #include #include #include #include #include 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 */ static u8 llvm_fullpath[PATH_MAX]; static u8 instrument_mode, instrument_opt_mode, ngram_size, lto_mode, cpp_mode; static u8 *lto_flag = AFL_CLANG_FLTO; static u8 debug; static u8 cwd[4096]; static u8 cmplog_mode; u8 use_stdin = 0; /* dummy */ // static u8 *march_opt = CFLAGS_OPT; enum { INSTURMENT_DEFAULT = 0, INSTRUMENT_CLASSIC = 1, INSTRUMENT_AFL = 1, INSTRUMENT_PCGUARD = 2, INSTRUMENT_INSTRIM = 3, INSTRUMENT_CFG = 3, INSTRUMENT_LTO = 4, INSTRUMENT_OPT_CTX = 8, INSTRUMENT_OPT_NGRAM = 16 }; char instrument_mode_string[18][18] = { "DEFAULT", "CLASSIC", "PCGUARD", "CFG", "LTO", "", "", "", "CTX", "", "", "", "", "", "", "", "NGRAM", "" }; u8 *getthecwd() { static u8 fail[] = ""; if (getcwd(cwd, sizeof(cwd)) == NULL) return fail; return cwd; } /* 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) { #ifdef __ANDROID__ tmp = alloc_printf("%s/afl-llvm-rt.so", afl_path); #else tmp = alloc_printf("%s/afl-llvm-rt.o", afl_path); #endif 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 = '/'; #ifdef __ANDROID__ tmp = alloc_printf("%s/afl-llvm-rt.so", dir); #else tmp = alloc_printf("%s/afl-llvm-rt.o", dir); #endif if (!access(tmp, R_OK)) { obj_path = dir; ck_free(tmp); return; } ck_free(tmp); ck_free(dir); } #ifdef __ANDROID__ if (!access(AFL_PATH "/afl-llvm-rt.so", R_OK)) { #else if (!access(AFL_PATH "/afl-llvm-rt.o", R_OK)) { #endif 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, char **envp) { u8 fortify_set = 0, asan_set = 0, x_set = 0, bit_mode = 0; u8 *name; cc_params = ck_alloc((argc + 128) * sizeof(u8 *)); name = strrchr(argv[0], '/'); if (!name) name = argv[0]; else ++name; if (lto_mode) if (lto_flag[0] != '-') FATAL( "Using afl-clang-lto is not possible because Makefile magic did not " "identify the correct -flto flag"); if (!strcmp(name, "afl-clang-fast++") || !strcmp(name, "afl-clang-lto++") || !strcmp(name, "afl-clang++")) { u8 *alt_cxx = getenv("AFL_CXX"); if (USE_BINDIR) snprintf(llvm_fullpath, sizeof(llvm_fullpath), "%s/clang++", LLVM_BINDIR); else sprintf(llvm_fullpath, CLANGPP_BIN); cc_params[0] = alt_cxx && *alt_cxx ? alt_cxx : (u8 *)llvm_fullpath; cpp_mode = 1; } else if (!strcmp(name, "afl-clang-fast") || !strcmp(name, "afl-clang-lto") || !strcmp(name, "afl-clang")) { u8 *alt_cc = getenv("AFL_CC"); if (USE_BINDIR) snprintf(llvm_fullpath, sizeof(llvm_fullpath), "%s/clang", LLVM_BINDIR); else sprintf(llvm_fullpath, CLANG_BIN); cc_params[0] = alt_cc && *alt_cc ? alt_cc : (u8 *)llvm_fullpath; } else { fprintf(stderr, "Name of the binary: %s\n", argv[0]); FATAL( "Name of the binary is not a known name, expected afl-clang-fast(++) " "or afl-clang-lto(++)"); } cc_params[cc_par_cnt++] = "-Wno-unused-command-line-argument"; if (lto_mode && cpp_mode) cc_params[cc_par_cnt++] = "-lc++"; // needed by fuzzbench, early /* There are several ways to compile with afl-clang-fast. In the traditional mode, we use afl-llvm-pass.so, then there is libLLVMInsTrim.so which is faster and creates less map pollution. Then there is the 'trace-pc-guard' mode, we use native LLVM instrumentation callbacks instead. For trace-pc-guard see: http://clang.llvm.org/docs/SanitizerCoverage.html#tracing-pcs-with-guards The best instrumentatation is with the LTO modes, the classic and InsTrimLTO, the latter is faster. The LTO modes are activated by using afl-clang-lto(++) */ if (lto_mode) { if (getenv("AFL_LLVM_WHITELIST") != NULL) { 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-lto-whitelist.so", obj_path); } } // laf if (getenv("LAF_SPLIT_SWITCHES") || getenv("AFL_LLVM_LAF_SPLIT_SWITCHES")) { 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/split-switches-pass.so", obj_path); } if (getenv("LAF_TRANSFORM_COMPARES") || getenv("AFL_LLVM_LAF_TRANSFORM_COMPARES")) { if (!be_quiet && getenv("AFL_LLVM_LTO_AUTODICTIONARY") && lto_mode) WARNF( "using AFL_LLVM_LAF_TRANSFORM_COMPARES together with " "AFL_LLVM_LTO_AUTODICTIONARY makes no sense. Use only " "AFL_LLVM_LTO_AUTODICTIONARY."); 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/compare-transform-pass.so", obj_path); } if (getenv("LAF_SPLIT_COMPARES") || getenv("AFL_LLVM_LAF_SPLIT_COMPARES")) { 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/split-compares-pass.so", obj_path); } // /laf unsetenv("AFL_LD"); unsetenv("AFL_LD_CALLER"); if (cmplog_mode) { 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/cmplog-routines-pass.so", obj_path); // reuse split switches from laf 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/split-switches-pass.so", obj_path); 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/cmplog-instructions-pass.so", obj_path); cc_params[cc_par_cnt++] = "-fno-inline"; } if (lto_mode) { cc_params[cc_par_cnt++] = alloc_printf("-fuse-ld=%s", AFL_REAL_LD); cc_params[cc_par_cnt++] = "-Wl,--allow-multiple-definition"; if (instrument_mode == INSTRUMENT_CFG) cc_params[cc_par_cnt++] = alloc_printf("-Wl,-mllvm=-load=%s/afl-llvm-lto-instrim.so", obj_path); else cc_params[cc_par_cnt++] = alloc_printf( "-Wl,-mllvm=-load=%s/afl-llvm-lto-instrumentation.so", obj_path); cc_params[cc_par_cnt++] = lto_flag; } else { if (instrument_mode == INSTRUMENT_PCGUARD) { cc_params[cc_par_cnt++] = "-fsanitize-coverage=trace-pc-guard"; // edge coverage by default } else { cc_params[cc_par_cnt++] = "-Xclang"; cc_params[cc_par_cnt++] = "-load"; cc_params[cc_par_cnt++] = "-Xclang"; if (instrument_mode == INSTRUMENT_CFG) cc_params[cc_par_cnt++] = alloc_printf("%s/libLLVMInsTrim.so", obj_path); else cc_params[cc_par_cnt++] = alloc_printf("%s/afl-llvm-pass.so", obj_path); } } // cc_params[cc_par_cnt++] = "-Qunused-arguments"; // in case LLVM is installed not via a package manager or "make install" // e.g. compiled download or compiled from github then it's ./lib directory // might not be in the search path. Add it if so. u8 *libdir = strdup(LLVM_LIBDIR); if (cpp_mode && strlen(libdir) && strncmp(libdir, "/usr", 4) && strncmp(libdir, "/lib", 4)) { cc_params[cc_par_cnt++] = "-rpath"; cc_params[cc_par_cnt++] = libdir; } else { free(libdir); } /* Detect stray -v calls from ./configure scripts. */ while (--argc) { u8 *cur = *(++argv); if (!strcmp(cur, "-m32")) bit_mode = 32; if (!strcmp(cur, "armv7a-linux-androideabi")) bit_mode = 32; if (!strcmp(cur, "-m64")) bit_mode = 64; if (!strcmp(cur, "-x")) x_set = 1; if (!strcmp(cur, "-fsanitize=address") || !strcmp(cur, "-fsanitize=memory")) asan_set = 1; if (strstr(cur, "FORTIFY_SOURCE")) fortify_set = 1; if (!strcmp(cur, "-Wl,-z,defs") || !strcmp(cur, "-Wl,--no-undefined")) continue; 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")) { if (getenv("AFL_USE_MSAN")) FATAL("ASAN and MSAN are mutually exclusive"); if (getenv("AFL_HARDEN")) FATAL("ASAN and AFL_HARDEN are mutually exclusive"); cc_params[cc_par_cnt++] = "-U_FORTIFY_SOURCE"; cc_params[cc_par_cnt++] = "-fsanitize=address"; } else if (getenv("AFL_USE_MSAN")) { if (getenv("AFL_USE_ASAN")) FATAL("ASAN and MSAN are mutually exclusive"); if (getenv("AFL_HARDEN")) FATAL("MSAN and AFL_HARDEN are mutually exclusive"); cc_params[cc_par_cnt++] = "-U_FORTIFY_SOURCE"; cc_params[cc_par_cnt++] = "-fsanitize=memory"; } } if (getenv("AFL_USE_UBSAN")) { cc_params[cc_par_cnt++] = "-fsanitize=undefined"; cc_params[cc_par_cnt++] = "-fsanitize-undefined-trap-on-error"; cc_params[cc_par_cnt++] = "-fno-sanitize-recover=all"; } if (getenv("AFL_USE_CFISAN")) { if (!lto_mode) { uint32_t i = 0, found = 0; while (envp[i] != NULL && !found) if (strncmp("-flto", envp[i++], 5) == 0) found = 1; if (!found) cc_params[cc_par_cnt++] = "-flto"; } cc_params[cc_par_cnt++] = "-fsanitize=cfi"; cc_params[cc_par_cnt++] = "-fvisibility=hidden"; } if (!getenv("AFL_DONT_OPTIMIZE")) { cc_params[cc_par_cnt++] = "-g"; cc_params[cc_par_cnt++] = "-O3"; cc_params[cc_par_cnt++] = "-funroll-loops"; // if (strlen(march_opt) > 1 && march_opt[0] == '-') // cc_params[cc_par_cnt++] = march_opt; } if (getenv("AFL_NO_BUILTIN") || getenv("AFL_LLVM_LAF_TRANSFORM_COMPARES") || getenv("LAF_TRANSFORM_COMPARES") || (lto_mode && (getenv("AFL_LLVM_LTO_AUTODICTIONARY") || getenv("AFL_LLVM_AUTODICTIONARY")))) { cc_params[cc_par_cnt++] = "-fno-builtin-strcmp"; cc_params[cc_par_cnt++] = "-fno-builtin-strncmp"; cc_params[cc_par_cnt++] = "-fno-builtin-strcasecmp"; cc_params[cc_par_cnt++] = "-fno-builtin-strncasecmp"; cc_params[cc_par_cnt++] = "-fno-builtin-memcmp"; cc_params[cc_par_cnt++] = "-fno-builtin-bcmp"; cc_params[cc_par_cnt++] = "-fno-builtin-strstr"; cc_params[cc_par_cnt++] = "-fno-builtin-strcasestr"; } #if defined(USEMMAP) && !defined(__HAIKU__) cc_params[cc_par_cnt++] = "-lrt"; #endif 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_FUZZ_INIT()=" "int __afl_sharedmem_fuzzing = 1;" "extern unsigned int *__afl_fuzz_len;" "extern unsigned char *__afl_fuzz_ptr;" "unsigned char *__afl_fuzz_alt_ptr;"; cc_params[cc_par_cnt++] = "-D__AFL_FUZZ_TESTCASE_BUF=(__afl_fuzz_ptr ? __afl_fuzz_ptr : " "(__afl_fuzz_alt_ptr = malloc(1 * 1024 * 1024)))"; cc_params[cc_par_cnt++] = "-D__AFL_FUZZ_TESTCASE_LEN=(__afl_fuzz_ptr ? *__afl_fuzz_len : read(0, " "__afl_fuzz_alt_ptr, 1 * 1024 * 1024))"; 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 (x_set) { cc_params[cc_par_cnt++] = "-x"; cc_params[cc_par_cnt++] = "none"; } #ifndef __ANDROID__ switch (bit_mode) { case 0: cc_params[cc_par_cnt++] = alloc_printf("%s/afl-llvm-rt.o", obj_path); if (lto_mode) cc_params[cc_par_cnt++] = alloc_printf("%s/afl-llvm-rt-lto.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"); if (lto_mode) { cc_params[cc_par_cnt++] = alloc_printf("%s/afl-llvm-rt-lto-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"); if (lto_mode) { cc_params[cc_par_cnt++] = alloc_printf("%s/afl-llvm-rt-lto-64.o", obj_path); if (access(cc_params[cc_par_cnt - 1], R_OK)) FATAL("-m64 is not supported by your compiler"); } break; } #endif cc_params[cc_par_cnt] = NULL; } /* Main entry point */ int main(int argc, char **argv, char **envp) { int i; char *callname = "afl-clang-fast", *ptr = NULL; if (getenv("AFL_DEBUG")) { debug = 1; if (strcmp(getenv("AFL_DEBUG"), "0") == 0) unsetenv("AFL_DEBUG"); } else if (getenv("AFL_QUIET")) be_quiet = 1; if (getenv("USE_TRACE_PC") || getenv("AFL_USE_TRACE_PC") || getenv("AFL_LLVM_USE_TRACE_PC") || getenv("AFL_TRACE_PC")) { if (instrument_mode == 0) instrument_mode = INSTRUMENT_PCGUARD; else if (instrument_mode != INSTRUMENT_PCGUARD) FATAL("you can not set AFL_LLVM_INSTRUMENT and AFL_TRACE_PC together"); } if (getenv("AFL_LLVM_INSTRIM") || getenv("INSTRIM") || getenv("INSTRIM_LIB")) { if (instrument_mode == 0) instrument_mode = INSTRUMENT_CFG; else if (instrument_mode != INSTRUMENT_CFG) FATAL( "you can not set AFL_LLVM_INSTRUMENT and AFL_LLVM_INSTRIM together"); } if (getenv("AFL_LLVM_CTX")) instrument_opt_mode |= INSTRUMENT_OPT_CTX; if (getenv("AFL_LLVM_NGRAM_SIZE")) { instrument_opt_mode |= INSTRUMENT_OPT_NGRAM; ngram_size = atoi(getenv("AFL_LLVM_NGRAM_SIZE")); if (ngram_size < 2 || ngram_size > NGRAM_SIZE_MAX) FATAL( "NGRAM instrumentation mode must be between 2 and NGRAM_SIZE_MAX " "(%u)", NGRAM_SIZE_MAX); } if (getenv("AFL_LLVM_INSTRUMENT")) { u8 *ptr = strtok(getenv("AFL_LLVM_INSTRUMENT"), ":,;"); while (ptr) { if (strncasecmp(ptr, "afl", strlen("afl")) == 0 || strncasecmp(ptr, "classic", strlen("classic")) == 0) { if (!instrument_mode || instrument_mode == INSTRUMENT_AFL) instrument_mode = INSTRUMENT_AFL; else FATAL("main instrumentation mode already set with %s", instrument_mode_string[instrument_mode]); } if (strncasecmp(ptr, "pc-guard", strlen("pc-guard")) == 0 || strncasecmp(ptr, "pcguard", strlen("pcgard")) == 0) { if (!instrument_mode || instrument_mode == INSTRUMENT_PCGUARD) instrument_mode = INSTRUMENT_PCGUARD; else FATAL("main instrumentation mode already set with %s", instrument_mode_string[instrument_mode]); } if (strncasecmp(ptr, "cfg", strlen("cfg")) == 0 || strncasecmp(ptr, "instrim", strlen("instrim")) == 0) { if (instrument_mode == INSTRUMENT_LTO) { instrument_mode = INSTRUMENT_CFG; lto_mode = 1; } else if (!instrument_mode || instrument_mode == INSTRUMENT_CFG) instrument_mode = INSTRUMENT_CFG; else FATAL("main instrumentation mode already set with %s", instrument_mode_string[instrument_mode]); } if (strncasecmp(ptr, "lto", strlen("lto")) == 0) { lto_mode = 1; if (!instrument_mode || instrument_mode == INSTRUMENT_LTO) instrument_mode = INSTRUMENT_LTO; else if (instrument_mode != INSTRUMENT_CFG) FATAL("main instrumentation mode already set with %s", instrument_mode_string[instrument_mode]); } if (strncasecmp(ptr, "ctx", strlen("ctx")) == 0) { instrument_opt_mode |= INSTRUMENT_OPT_CTX; setenv("AFL_LLVM_CTX", "1", 1); } if (strncasecmp(ptr, "ngram", strlen("ngram")) == 0) { ptr += strlen("ngram"); while (*ptr && (*ptr < '0' || *ptr > '9')) ptr++; if (!*ptr) if ((ptr = getenv("AFL_LLVM_NGRAM_SIZE")) != NULL) FATAL( "you must set the NGRAM size with (e.g. for value 2) " "AFL_LLVM_INSTRUMENT=ngram-2"); ngram_size = atoi(ptr); if (ngram_size < 2 || ngram_size > NGRAM_SIZE_MAX) FATAL( "NGRAM instrumentation option must be between 2 and " "NGRAM_SIZE_MAX " "(%u)", NGRAM_SIZE_MAX); instrument_opt_mode |= (INSTRUMENT_OPT_NGRAM); ptr = alloc_printf("%u", ngram_size); setenv("AFL_LLVM_NGRAM_SIZE", ptr, 1); } ptr = strtok(NULL, ":,;"); } } if (strstr(argv[0], "afl-clang-lto") != NULL) { if (instrument_mode == 0 || instrument_mode == INSTRUMENT_LTO || instrument_mode == INSTRUMENT_CFG) { lto_mode = 1; callname = "afl-clang-lto"; if (!instrument_mode) { instrument_mode = INSTRUMENT_LTO; ptr = instrument_mode_string[instrument_mode]; } } else { if (!be_quiet) WARNF("afl-clang-lto called with mode %s, using that mode instead", instrument_mode_string[instrument_mode]); } } if (instrument_mode == 0) { #ifndef USE_TRACE_PC if (getenv("AFL_LLVM_WHITELIST")) instrument_mode = INSTRUMENT_AFL; else #endif instrument_mode = INSTRUMENT_PCGUARD; } if (instrument_opt_mode && lto_mode) FATAL( "CTX and NGRAM can not be used in LTO mode (and would make LTO " "useless)"); if (!instrument_opt_mode) { if (lto_mode && instrument_mode == INSTRUMENT_CFG) ptr = alloc_printf("InsTrimLTO"); else ptr = instrument_mode_string[instrument_mode]; } else if (instrument_opt_mode == INSTRUMENT_OPT_CTX) ptr = alloc_printf("%s + CTX", instrument_mode_string[instrument_mode]); else if (instrument_opt_mode == INSTRUMENT_OPT_NGRAM) ptr = alloc_printf("%s + NGRAM-%u", instrument_mode_string[instrument_mode], ngram_size); else ptr = alloc_printf("%s + CTX + NGRAM-%u", instrument_mode_string[instrument_mode], ngram_size); #ifndef AFL_CLANG_FLTO if (lto_mode) FATAL( "instrumentation mode LTO specified but LLVM support not available " "(requires LLVM 11 or higher)"); #endif if (instrument_opt_mode && instrument_mode != INSTRUMENT_CLASSIC && instrument_mode != INSTRUMENT_CFG) FATAL( "CTX and NGRAM instrumentation options can only be used with CFG " "(recommended) and CLASSIC instrumentation modes!"); if (getenv("AFL_LLVM_SKIP_NEVERZERO") && getenv("AFL_LLVM_NOT_ZERO")) FATAL( "AFL_LLVM_NOT_ZERO and AFL_LLVM_SKIP_NEVERZERO can not be set " "together"); if (instrument_mode == INSTRUMENT_PCGUARD && getenv("AFL_LLVM_WHITELIST")) WARNF("Instrumentation type PCGUARD does not support AFL_LLVM_WHITELIST!"); if (argc < 2 || strcmp(argv[1], "-h") == 0) { if (!lto_mode) printf("afl-clang-fast" VERSION " by in %s mode\n", ptr); else printf("afl-clang-lto" VERSION " by Marc \"vanHauser\" Heuse in %s mode\n", ptr); SAYF( "\n" "%s[++] [options]\n" "\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" "Environment variables used:\n" "AFL_CC: path to the C compiler to use\n" "AFL_CXX: path to the C++ compiler to use\n" "AFL_DEBUG: enable developer debugging output\n" "AFL_DONT_OPTIMIZE: disable optimization instead of -O3\n" "AFL_HARDEN: adds code hardening to catch memory bugs\n" "AFL_INST_RATIO: percentage of branches to instrument\n" "AFL_LLVM_NOT_ZERO: use cycling trace counters that skip zero\n" "AFL_LLVM_SKIP_NEVERZERO: do not skip zero on trace counters\n" "AFL_LLVM_LAF_SPLIT_COMPARES: enable cascaded comparisons\n" "AFL_LLVM_LAF_SPLIT_COMPARES_BITW: size limit (default 8)\n" "AFL_LLVM_LAF_SPLIT_SWITCHES: casc. comp. in 'switch'\n" " to cascaded comparisons\n" "AFL_LLVM_LAF_SPLIT_FLOATS: transform floating point comp. to " "cascaded comp.\n" "AFL_LLVM_LAF_TRANSFORM_COMPARES: transform library comparison " "function calls\n" "AFL_LLVM_LAF_ALL: enables all LAF splits/transforms\n" "AFL_LLVM_WHITELIST: enable whitelisting (selective " "instrumentation)\n" "AFL_NO_BUILTIN: compile for use with libtokencap.so\n" "AFL_PATH: path to instrumenting pass and runtime " "(afl-llvm-rt.*o)\n" "AFL_QUIET: suppress verbose output\n" "AFL_USE_ASAN: activate address sanitizer\n" "AFL_USE_CFISAN: activate control flow sanitizer\n" "AFL_USE_MSAN: activate memory sanitizer\n" "AFL_USE_UBSAN: activate undefined behaviour sanitizer\n", callname, BIN_PATH, BIN_PATH); SAYF( "\nafl-clang-fast specific environment variables:\n" "AFL_LLVM_CMPLOG: log operands of comparisons (RedQueen mutator)\n" "AFL_LLVM_INSTRUMENT: set instrumentation mode: AFL, CFG " "(INSTRIM), PCGUARD [DEFAULT], LTO, CTX, NGRAM-2 ... NGRAM-16\n" " You can also use the old environment variables instead:\n" " AFL_LLVM_USE_TRACE_PC: use LLVM trace-pc-guard instrumentation " "[DEFAULT]\n" " AFL_LLVM_INSTRIM: use light weight instrumentation InsTrim\n" " AFL_LLVM_INSTRIM_LOOPHEAD: optimize loop tracing for speed (" "option to INSTRIM)\n" " AFL_LLVM_CTX: use context sensitive coverage\n" " AFL_LLVM_NGRAM_SIZE: use ngram prev_loc count coverage\n"); #ifdef AFL_CLANG_FLTO SAYF( "\nafl-clang-lto specific environment variables:\n" "AFL_LLVM_LTO_DONTWRITEID: don't write the highest ID used to a " "global var\n" "AFL_LLVM_LTO_STARTID: from which ID to start counting from for a " "bb\n" "AFL_REAL_LD: use this lld linker instead of the compiled in path\n" "\nafl-clang-lto was built with linker target \"%s\" and LTO flags " "\"%s\"\n" "If anything fails - be sure to read README.lto.md!\n", AFL_REAL_LD, AFL_CLANG_FLTO); #endif SAYF( "\nafl-clang-fast was built for llvm %s with the llvm binary path " "of \"%s\".\n", LLVM_VERSION, LLVM_BINDIR); SAYF("\n"); exit(1); } else if ((isatty(2) && !be_quiet) || getenv("AFL_DEBUG") != NULL) { if (!lto_mode) SAYF(cCYA "afl-clang-fast" VERSION cRST " by in %s mode\n", ptr); else SAYF(cCYA "afl-clang-lto" VERSION cRST " by Marc \"vanHauser\" Heuse in mode %s\n", ptr); } u8 *ptr2; if (!be_quiet && !lto_mode && ((ptr2 = getenv("AFL_MAP_SIZE")) || (ptr2 = getenv("AFL_MAPSIZE")))) { u32 map_size = atoi(ptr2); if (map_size != MAP_SIZE) FATAL("AFL_MAP_SIZE is not supported by afl-clang-fast"); } if (debug) { SAYF(cMGN "[D]" cRST " cd \"%s\";", getthecwd()); for (i = 0; i < argc; i++) SAYF(" \"%s\"", argv[i]); SAYF("\n"); } check_environment_vars(envp); if (getenv("AFL_LLVM_LAF_ALL")) { setenv("AFL_LLVM_LAF_SPLIT_SWITCHES", "1", 1); setenv("AFL_LLVM_LAF_SPLIT_COMPARES", "1", 1); setenv("AFL_LLVM_LAF_SPLIT_FLOATS", "1", 1); setenv("AFL_LLVM_LAF_TRANSFORM_COMPARES", "1", 1); } cmplog_mode = getenv("AFL_CMPLOG") || getenv("AFL_LLVM_CMPLOG"); if (!be_quiet && cmplog_mode) printf("CmpLog mode by \n"); #ifndef __ANDROID__ find_obj(argv[0]); #endif edit_params(argc, argv, envp); if (debug) { SAYF(cMGN "[D]" cRST " cd \"%s\";", getthecwd()); for (i = 0; i < cc_par_cnt; i++) SAYF(" \"%s\"", cc_params[i]); SAYF("\n"); } execvp(cc_params[0], (char **)cc_params); FATAL("Oops, failed to execute '%s' - check your PATH", cc_params[0]); return 0; }