third_party/afl/src/afl-gcc.c - chromium/src - Git at Google

 /*
    american fuzzy lop - wrapper for GCC and clang
    ----------------------------------------------

    Written and maintained by Michal Zalewski <lcamtuf@google.com>

    Copyright 2013, 2014, 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 or clang. The most common way
    of using it is to pass the path to afl-gcc or afl-clang via CC when invoking
    ./configure.

    (Of course, use CXX and point it to afl-g++ / afl-clang++ for C++ code.)

    The wrapper needs to know the path to afl-as (renamed to 'as'). The default
    is /usr/local/lib/afl/. A convenient way to specify alternative directories
    would be to set AFL_PATH.

    If AFL_HARDEN is set, the wrapper will compile the target app with various
    hardening options that may help detect memory management issues more
    reliably. You can also specify AFL_USE_ASAN to enable ASAN.

    If you want to call a non-default compiler as a next step of the chain,
    specify its location via AFL_CC or AFL_CXX.

  */

 #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*  as_path;                /* Path to the AFL 'as' wrapper      */
 static u8** cc_params;              /* Parameters passed to the real CC  */
 static u32  cc_par_cnt = 1;         /* Param count, including argv0      */
 static u8   be_quiet,               /* Quiet mode                        */
             clang_mode;             /* Invoked as afl-clang*?            */


 /* Try to find our "fake" GNU assembler in AFL_PATH or at the location derived
    from argv[0]. If that fails, abort. */

 static void find_as(u8* argv0) {

   u8 *afl_path = getenv("AFL_PATH");
   u8 *slash, *tmp;

   if (afl_path) {

     tmp = alloc_printf("%s/as", afl_path);

     if (!access(tmp, X_OK)) {
       as_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-as", dir);

     if (!access(tmp, X_OK)) {
       as_path = dir;
       ck_free(tmp);
       return;
     }

     ck_free(tmp);
     ck_free(dir);

   }

   if (!access(AFL_PATH "/as", X_OK)) {
     as_path = AFL_PATH;
     return;
   }

   FATAL("Unable to find AFL wrapper binary for 'as'. 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;
   u8 *name;

 #if defined(__FreeBSD__) && defined(__x86_64__)
   u8 m32_set = 0;
 #endif

   cc_params = ck_alloc((argc + 128) * sizeof(u8*));

   name = strrchr(argv[0], '/');
   if (!name) name = argv[0]; else name++;

   if (!strncmp(name, "afl-clang", 9)) {

     clang_mode = 1;

     setenv(CLANG_ENV_VAR, "1", 1);

     if (!strcmp(name, "afl-clang++")) {
       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";
     }

   } else {

     /* With GCJ and Eclipse installed, you can actually compile Java! The
        instrumentation will work (amazingly). Alas, unhandled exceptions do
        not call abort(), so afl-fuzz would need to be modified to equate
        non-zero exit codes with crash conditions when working with Java
        binaries. Meh. */

 #ifdef __APPLE__

     if (!strcmp(name, "afl-g++")) cc_params[0] = getenv("AFL_CXX");
     else if (!strcmp(name, "afl-gcj")) cc_params[0] = getenv("AFL_GCJ");
     else cc_params[0] = getenv("AFL_CC");

     if (!cc_params[0]) {

       SAYF("\n" cLRD "[-] " cRST
            "On Apple systems, 'gcc' is usually just a wrapper for clang. Please use the\n"
            "    'afl-clang' utility instead of 'afl-gcc'. If you really have GCC installed,\n"
            "    set AFL_CC or AFL_CXX to specify the correct path to that compiler.\n");

       FATAL("AFL_CC or AFL_CXX required on MacOS X");

     }

 #else

     if (!strcmp(name, "afl-g++")) {
       u8* alt_cxx = getenv("AFL_CXX");
       cc_params[0] = alt_cxx ? alt_cxx : (u8*)"g++";
     } else if (!strcmp(name, "afl-gcj")) {
       u8* alt_cc = getenv("AFL_GCJ");
       cc_params[0] = alt_cc ? alt_cc : (u8*)"gcj";
     } else {
       u8* alt_cc = getenv("AFL_CC");
       cc_params[0] = alt_cc ? alt_cc : (u8*)"gcc";
     }

 #endif /* __APPLE__ */

   }

   while (--argc) {
     u8* cur = *(++argv);

     if (!strncmp(cur, "-B", 2)) {

       if (!be_quiet) WARNF("-B is already set, overriding");

       if (!cur[2] && argc > 1) { argc--; argv++; }
       continue;

     }

     if (!strcmp(cur, "-integrated-as")) continue;

     if (!strcmp(cur, "-pipe")) continue;

 #if defined(__FreeBSD__) && defined(__x86_64__)
     if (!strcmp(cur, "-m32")) m32_set = 1;
 #endif

     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;

   }

   cc_params[cc_par_cnt++] = "-B";
   cc_params[cc_par_cnt++] = as_path;

   if (clang_mode)
     cc_params[cc_par_cnt++] = "-no-integrated-as";

   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) {

     /* Pass this on to afl-as to adjust map density. */

     setenv("AFL_USE_ASAN", "1", 1);

   } else 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_DONT_OPTIMIZE")) {

 #if defined(__FreeBSD__) && defined(__x86_64__)

     /* On 64-bit FreeBSD systems, clang -g -m32 is broken, but -m32 itself
        works OK. This has nothing to do with us, but let's avoid triggering
        that bug. */

     if (!clang_mode || !m32_set)
       cc_params[cc_par_cnt++] = "-g";

 #else

       cc_params[cc_par_cnt++] = "-g";

 #endif

     cc_params[cc_par_cnt++] = "-O3";
     cc_params[cc_par_cnt++] = "-funroll-loops";

     /* Two indicators that you're building for fuzzing; one of them is
        AFL-specific, the other is shared with libfuzzer. */

     cc_params[cc_par_cnt++] = "-D__AFL_COMPILER=1";
     cc_params[cc_par_cnt++] = "-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION=1";

   }

   if (getenv("AFL_NO_BUILTIN")) {

     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-strstr";
     cc_params[cc_par_cnt++] = "-fno-builtin-strcasestr";

   }

   cc_params[cc_par_cnt] = NULL;

 }


 /* Main entry point */

 int main(int argc, char** argv) {

   if (isatty(2) && !getenv("AFL_QUIET")) {

     SAYF(cCYA "afl-cc " cBRI VERSION cRST " by <lcamtuf@google.com>\n");

   } else be_quiet = 1;

   if (argc < 2) {

     SAYF("\n"
          "This is a helper application for afl-fuzz. It serves as a drop-in replacement\n"
          "for gcc or clang, letting you recompile third-party code with the required\n"
          "runtime instrumentation. A common use pattern would be one of the following:\n\n"

          "  CC=%s/afl-gcc ./configure\n"
          "  CXX=%s/afl-g++ ./configure\n\n"

          "You can specify custom next-stage toolchain via AFL_CC, AFL_CXX, and AFL_AS.\n"
          "Setting AFL_HARDEN enables hardening optimizations in the compiled code.\n\n",
          BIN_PATH, BIN_PATH);

     exit(1);

   }

   find_as(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;

 }
	/*
	american fuzzy lop - wrapper for GCC and clang
	----------------------------------------------

	Written and maintained by Michal Zalewski <lcamtuf@google.com>

	Copyright 2013, 2014, 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 or clang. The most common way
	of using it is to pass the path to afl-gcc or afl-clang via CC when invoking
	./configure.

	(Of course, use CXX and point it to afl-g++ / afl-clang++ for C++ code.)

	The wrapper needs to know the path to afl-as (renamed to 'as'). The default
	is /usr/local/lib/afl/. A convenient way to specify alternative directories
	would be to set AFL_PATH.

	If AFL_HARDEN is set, the wrapper will compile the target app with various
	hardening options that may help detect memory management issues more
	reliably. You can also specify AFL_USE_ASAN to enable ASAN.

	If you want to call a non-default compiler as a next step of the chain,
	specify its location via AFL_CC or AFL_CXX.

	*/

	#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* as_path; /* Path to the AFL 'as' wrapper */
	static u8** cc_params; /* Parameters passed to the real CC */
	static u32 cc_par_cnt = 1; /* Param count, including argv0 */
	static u8 be_quiet, /* Quiet mode */
	clang_mode; /* Invoked as afl-clang? /


	/* Try to find our "fake" GNU assembler in AFL_PATH or at the location derived
	from argv[0]. If that fails, abort. */

	static void find_as(u8* argv0) {

	u8 *afl_path = getenv("AFL_PATH");
	u8 slash, tmp;

	if (afl_path) {

	tmp = alloc_printf("%s/as", afl_path);

	if (!access(tmp, X_OK)) {
	as_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-as", dir);

	if (!access(tmp, X_OK)) {
	as_path = dir;
	ck_free(tmp);
	return;
	}

	ck_free(tmp);
	ck_free(dir);

	}

	if (!access(AFL_PATH "/as", X_OK)) {
	as_path = AFL_PATH;
	return;
	}

	FATAL("Unable to find AFL wrapper binary for 'as'. 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;
	u8 *name;

	#if defined(__FreeBSD__) && defined(__x86_64__)
	u8 m32_set = 0;
	#endif

	cc_params = ck_alloc((argc + 128) * sizeof(u8*));

	name = strrchr(argv[0], '/');
	if (!name) name = argv[0]; else name++;

	if (!strncmp(name, "afl-clang", 9)) {

	clang_mode = 1;

	setenv(CLANG_ENV_VAR, "1", 1);

	if (!strcmp(name, "afl-clang++")) {
	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";
	}

	} else {

	/* With GCJ and Eclipse installed, you can actually compile Java! The
	instrumentation will work (amazingly). Alas, unhandled exceptions do
	not call abort(), so afl-fuzz would need to be modified to equate
	non-zero exit codes with crash conditions when working with Java
	binaries. Meh. */

	#ifdef __APPLE__

	if (!strcmp(name, "afl-g++")) cc_params[0] = getenv("AFL_CXX");
	else if (!strcmp(name, "afl-gcj")) cc_params[0] = getenv("AFL_GCJ");
	else cc_params[0] = getenv("AFL_CC");

	if (!cc_params[0]) {

	SAYF("\n" cLRD "[-] " cRST
	"On Apple systems, 'gcc' is usually just a wrapper for clang. Please use the\n"
	" 'afl-clang' utility instead of 'afl-gcc'. If you really have GCC installed,\n"
	" set AFL_CC or AFL_CXX to specify the correct path to that compiler.\n");

	FATAL("AFL_CC or AFL_CXX required on MacOS X");

	}

	#else

	if (!strcmp(name, "afl-g++")) {
	u8* alt_cxx = getenv("AFL_CXX");
	cc_params[0] = alt_cxx ? alt_cxx : (u8*)"g++";
	} else if (!strcmp(name, "afl-gcj")) {
	u8* alt_cc = getenv("AFL_GCJ");
	cc_params[0] = alt_cc ? alt_cc : (u8*)"gcj";
	} else {
	u8* alt_cc = getenv("AFL_CC");
	cc_params[0] = alt_cc ? alt_cc : (u8*)"gcc";
	}

	#endif /* __APPLE__ */

	}

	while (--argc) {
	u8* cur = *(++argv);

	if (!strncmp(cur, "-B", 2)) {

	if (!be_quiet) WARNF("-B is already set, overriding");

	if (!cur[2] && argc > 1) { argc--; argv++; }
	continue;

	}

	if (!strcmp(cur, "-integrated-as")) continue;

	if (!strcmp(cur, "-pipe")) continue;

	#if defined(__FreeBSD__) && defined(__x86_64__)
	if (!strcmp(cur, "-m32")) m32_set = 1;
	#endif

	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;

	}

	cc_params[cc_par_cnt++] = "-B";
	cc_params[cc_par_cnt++] = as_path;

	if (clang_mode)
	cc_params[cc_par_cnt++] = "-no-integrated-as";

	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) {

	/* Pass this on to afl-as to adjust map density. */

	setenv("AFL_USE_ASAN", "1", 1);

	} else 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_DONT_OPTIMIZE")) {

	#if defined(__FreeBSD__) && defined(__x86_64__)

	/* On 64-bit FreeBSD systems, clang -g -m32 is broken, but -m32 itself
	works OK. This has nothing to do with us, but let's avoid triggering
	that bug. */

	if (!clang_mode \|\| !m32_set)
	cc_params[cc_par_cnt++] = "-g";

	#else

	cc_params[cc_par_cnt++] = "-g";

	#endif

	cc_params[cc_par_cnt++] = "-O3";
	cc_params[cc_par_cnt++] = "-funroll-loops";

	/* Two indicators that you're building for fuzzing; one of them is
	AFL-specific, the other is shared with libfuzzer. */

	cc_params[cc_par_cnt++] = "-D__AFL_COMPILER=1";
	cc_params[cc_par_cnt++] = "-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION=1";

	}

	if (getenv("AFL_NO_BUILTIN")) {

	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-strstr";
	cc_params[cc_par_cnt++] = "-fno-builtin-strcasestr";

	}

	cc_params[cc_par_cnt] = NULL;

	}


	/* Main entry point */

	int main(int argc, char** argv) {

	if (isatty(2) && !getenv("AFL_QUIET")) {

	SAYF(cCYA "afl-cc " cBRI VERSION cRST " by <lcamtuf@google.com>\n");

	} else be_quiet = 1;

	if (argc < 2) {

	SAYF("\n"
	"This is a helper application for afl-fuzz. It serves as a drop-in replacement\n"
	"for gcc or clang, letting you recompile third-party code with the required\n"
	"runtime instrumentation. A common use pattern would be one of the following:\n\n"

	" CC=%s/afl-gcc ./configure\n"
	" CXX=%s/afl-g++ ./configure\n\n"

	"You can specify custom next-stage toolchain via AFL_CC, AFL_CXX, and AFL_AS.\n"
	"Setting AFL_HARDEN enables hardening optimizations in the compiled code.\n\n",
	BIN_PATH, BIN_PATH);

	exit(1);

	}

	find_as(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;

	}