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Diffstat (limited to 'src/afl-ld-lto.c')
| -rw-r--r-- | src/afl-ld-lto.c | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/src/afl-ld-lto.c b/src/afl-ld-lto.c new file mode 100644 index 00000000..771e2d0d --- /dev/null +++ b/src/afl-ld-lto.c @@ -0,0 +1,358 @@ +/* + american fuzzy lop++ - wrapper for llvm 11+ lld + ----------------------------------------------- + + Written by Marc Heuse <mh@mh-sec.de> for afl++ + + Maintained by Marc Heuse <mh@mh-sec.de>, + Heiko Eißfeldt <heiko.eissfeldt@hexco.de> + Andrea Fioraldi <andreafioraldi@gmail.com> + Dominik Maier <domenukk@gmail.com> + + 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 + + The sole purpose of this wrapper is to preprocess clang LTO files when + linking with lld and performing the instrumentation on the whole program. + +*/ + +#define AFL_MAIN +#define _GNU_SOURCE + +#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> +#include <time.h> +#include <ctype.h> +#include <fcntl.h> + +#include <sys/stat.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <sys/time.h> + +#include <dirent.h> + +#define MAX_PARAM_COUNT 4096 + +static u8 **ld_params; /* Parameters passed to the real 'ld' */ + +static u8 *afl_path = AFL_PATH; +static u8 *real_ld = AFL_REAL_LD; + +static u8 be_quiet, /* Quiet mode (no stderr output) */ + debug, /* AFL_DEBUG */ + passthrough, /* AFL_LD_PASSTHROUGH - no link+optimize*/ + just_version; /* Just show version? */ + +static u32 ld_param_cnt = 1; /* Number of params to 'ld' */ + +/* Examine and modify parameters to pass to 'ld', 'llvm-link' and 'llmv-ar'. + Note that the file name is always the last parameter passed by GCC, + so we exploit this property to keep the code "simple". */ +static void edit_params(int argc, char **argv) { + + u32 i, instrim = 0, gold_pos = 0, gold_present = 0, rt_present = 0, + rt_lto_present = 0, inst_present = 0; + char *ptr; + + ld_params = ck_alloc(4096 * sizeof(u8 *)); + + ld_params[0] = (u8 *)real_ld; + + if (!passthrough) { + + for (i = 1; i < argc; i++) { + + if (strstr(argv[i], "/afl-llvm-rt-lto.o") != NULL) rt_lto_present = 1; + if (strstr(argv[i], "/afl-llvm-rt.o") != NULL) rt_present = 1; + if (strstr(argv[i], "/afl-llvm-lto-instr") != NULL) inst_present = 1; + + } + + for (i = 1; i < argc && !gold_pos; i++) { + + if (strcmp(argv[i], "-plugin") == 0) { + + if (strncmp(argv[i], "-plugin=", strlen("-plugin=")) == 0) { + + if (strcasestr(argv[i], "LLVMgold.so") != NULL) + gold_present = gold_pos = i + 1; + + } else if (i < argc && strcasestr(argv[i + 1], "LLVMgold.so") != NULL) { + + gold_present = gold_pos = i + 2; + + } + + } + + } + + if (!gold_pos) { + + for (i = 1; i + 1 < argc && !gold_pos; i++) { + + if (argv[i][0] != '-') { + + if (argv[i - 1][0] == '-') { + + switch (argv[i - 1][1]) { + + case 'b': + break; + case 'd': + break; + case 'e': + break; + case 'F': + break; + case 'f': + break; + case 'I': + break; + case 'l': + break; + case 'L': + break; + case 'm': + break; + case 'o': + break; + case 'O': + break; + case 'p': + if (index(argv[i - 1], '=') == NULL) gold_pos = i; + break; + case 'R': + break; + case 'T': + break; + case 'u': + break; + case 'y': + break; + case 'z': + break; + case '-': { + + if (strcmp(argv[i - 1], "--oformat") == 0) break; + if (strcmp(argv[i - 1], "--output") == 0) break; + if (strncmp(argv[i - 1], "--opt-remarks-", 14) == 0) break; + gold_pos = i; + break; + + } + + default: + gold_pos = i; + + } + + } else + + gold_pos = i; + + } + + } + + } + + if (!gold_pos) gold_pos = 1; + + } + + if (getenv("AFL_LLVM_INSTRIM")) + instrim = 1; + else if ((ptr = getenv("AFL_LLVM_INSTRUMENT")) && + (strcasestr(ptr, "CFG") == 0 || strcasestr(ptr, "INSTRIM") == 0)) + instrim = 1; + + if (debug) + SAYF(cMGN "[D] " cRST + "passthrough=%s instrim=%d, gold_pos=%d, gold_present=%s " + "inst_present=%s rt_present=%s rt_lto_present=%s\n", + passthrough ? "true" : "false", instrim, gold_pos, + gold_present ? "true" : "false", inst_present ? "true" : "false", + rt_present ? "true" : "false", rt_lto_present ? "true" : "false"); + + for (i = 1; i < argc; i++) { + + if (ld_param_cnt >= MAX_PARAM_COUNT) + FATAL( + "Too many command line parameters because of unpacking .a archives, " + "this would need to be done by hand ... sorry! :-("); + + if (strcmp(argv[i], "--afl") == 0) { + + if (!be_quiet) OKF("afl++ test command line flag detected, exiting."); + exit(0); + + } + + if (i == gold_pos && !passthrough) { + + ld_params[ld_param_cnt++] = alloc_printf("-L%s/../lib", LLVM_BINDIR); + + if (!gold_present) { + + ld_params[ld_param_cnt++] = "-plugin"; + ld_params[ld_param_cnt++] = + alloc_printf("%s/../lib/LLVMgold.so", LLVM_BINDIR); + + } + + ld_params[ld_param_cnt++] = "--allow-multiple-definition"; + + if (!inst_present) { + + if (instrim) + ld_params[ld_param_cnt++] = + alloc_printf("-mllvm=-load=%s/afl-llvm-lto-instrim.so", afl_path); + else + ld_params[ld_param_cnt++] = alloc_printf( + "-mllvm=-load=%s/afl-llvm-lto-instrumentation.so", afl_path); + + } + + if (!rt_present) + ld_params[ld_param_cnt++] = alloc_printf("%s/afl-llvm-rt.o", afl_path); + if (!rt_lto_present) + ld_params[ld_param_cnt++] = + alloc_printf("%s/afl-llvm-rt-lto.o", afl_path); + + } + + ld_params[ld_param_cnt++] = argv[i]; + + } + + ld_params[ld_param_cnt] = NULL; + +} + +/* Main entry point */ + +int main(int argc, char **argv) { + + s32 pid, i, status; + u8 * ptr; + char thecwd[PATH_MAX]; + + if ((ptr = getenv("AFL_LD_CALLER")) != NULL) { + + FATAL("ld loop detected! Set AFL_REAL_LD!\n"); + + } + + if (isatty(2) && !getenv("AFL_QUIET") && !getenv("AFL_DEBUG")) { + + SAYF(cCYA "afl-ld-to" VERSION cRST + " by Marc \"vanHauser\" Heuse <mh@mh-sec.de>\n"); + + } else + + be_quiet = 1; + + if (getenv("AFL_DEBUG") != NULL) debug = 1; + if (getenv("AFL_PATH") != NULL) afl_path = getenv("AFL_PATH"); + if (getenv("AFL_LD_PASSTHROUGH") != NULL) passthrough = 1; + if (getenv("AFL_REAL_LD") != NULL) real_ld = getenv("AFL_REAL_LD"); + + if (!afl_path || !*afl_path) afl_path = "/usr/local/lib/afl"; + + setenv("AFL_LD_CALLER", "1", 1); + + if (debug) { + + if (getcwd(thecwd, sizeof(thecwd)) != 0) strcpy(thecwd, "."); + + SAYF(cMGN "[D] " cRST "cd \"%s\";", thecwd); + for (i = 0; i < argc; i++) + SAYF(" \"%s\"", argv[i]); + SAYF("\n"); + + } + + if (argc < 2) { + + SAYF( + "\n" + "This is a helper application for afl-clang-lto. It is a wrapper " + "around GNU " + "llvm's 'lld',\n" + "executed by the toolchain whenever using " + "afl-clang-lto/afl-clang-lto++.\n" + "You probably don't want to run this program directly but rather pass " + "it as LD parameter to configure scripts\n\n" + + "Environment variables:\n" + " AFL_LD_PASSTHROUGH do not link+optimize == no instrumentation\n" + " AFL_REAL_LD point to the real llvm 11 lld if necessary\n" + + "\nafl-ld-to was compiled with the fixed real 'ld' of %s and the " + "binary path of %s\n\n", + real_ld, LLVM_BINDIR); + + exit(1); + + } + + edit_params(argc, argv); // here most of the magic happens :-) + + if (debug) { + + SAYF(cMGN "[D]" cRST " cd \"%s\";", thecwd); + for (i = 0; i < ld_param_cnt; i++) + SAYF(" \"%s\"", ld_params[i]); + SAYF("\n"); + + } + + if (!(pid = fork())) { + + if (strlen(real_ld) > 1) execvp(real_ld, (char **)ld_params); + execvp("ld", (char **)ld_params); // fallback + FATAL("Oops, failed to execute 'ld' - check your PATH"); + + } + + if (pid < 0) PFATAL("fork() failed"); + + if (waitpid(pid, &status, 0) <= 0) PFATAL("waitpid() failed"); + if (debug) SAYF(cMGN "[D] " cRST "linker result: %d\n", status); + + if (!just_version) { + + if (status == 0) { + + if (!be_quiet) OKF("Linker was successful"); + + } else { + + SAYF(cLRD "[-] " cRST + "Linker failed, please investigate and send a bug report. Most " + "likely an 'ld' option is incompatible with %s.\n", + AFL_CLANG_FLTO); + + } + + } + + exit(WEXITSTATUS(status)); + +} + |