diff options
| -rw-r--r-- | src/afl-cc.c | 102 |
1 files changed, 57 insertions, 45 deletions
diff --git a/src/afl-cc.c b/src/afl-cc.c index 35b90a5c..7f15ad76 100644 --- a/src/afl-cc.c +++ b/src/afl-cc.c @@ -1101,37 +1101,45 @@ static void edit_params(u32 argc, char **argv, char **envp) { if (!have_c) 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: + /* As documented in instrumentation/README.persistent_mode.md, deferred + forkserver initialization and persistent mode are not available in afl-gcc + and afl-clang. */ + if (compiler_mode != GCC && compiler_mode != CLANG) { - 1) We need to convince the compiler not to optimize out the signature. - This is done with __attribute__((used)). + cc_params[cc_par_cnt++] = "-D__AFL_HAVE_MANUAL_CONTROL=1"; - 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. + /* 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: - 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. + 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. - 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[1048576];" - "unsigned char *__afl_fuzz_alt_ptr = __afl_fuzz_alt;"; + 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[1048576];" + "unsigned char *__afl_fuzz_alt_ptr = __afl_fuzz_alt;"; + + } if (plusplus_mode) { @@ -1169,35 +1177,39 @@ static void edit_params(u32 argc, char **argv, char **envp) { "(*__afl_fuzz_len = read(0, __afl_fuzz_alt_ptr, 1048576)) == 0xffffffff " "? 0 : *__afl_fuzz_len)"; - cc_params[cc_par_cnt++] = - "-D__AFL_LOOP(_A)=" - "({ static volatile const char *_B __attribute__((used,unused)); " - " _B = (const char*)\"" PERSIST_SIG - "\"; " - "extern int __afl_connected;" + if (compiler_mode != GCC && compiler_mode != CLANG) { + + cc_params[cc_par_cnt++] = + "-D__AFL_LOOP(_A)=" + "({ static volatile const char *_B __attribute__((used,unused)); " + " _B = (const char*)\"" PERSIST_SIG + "\"; " + "extern int __afl_connected;" #ifdef __APPLE__ - "__attribute__((visibility(\"default\"))) " - "int _L(unsigned int) __asm__(\"___afl_persistent_loop\"); " + "__attribute__((visibility(\"default\"))) " + "int _L(unsigned int) __asm__(\"___afl_persistent_loop\"); " #else - "__attribute__((visibility(\"default\"))) " - "int _L(unsigned int) __asm__(\"__afl_persistent_loop\"); " + "__attribute__((visibility(\"default\"))) " + "int _L(unsigned int) __asm__(\"__afl_persistent_loop\"); " #endif /* ^__APPLE__ */ - // if afl is connected, we run _A times, else once. - "_L(__afl_connected ? _A : 1); })"; + // if afl is connected, we run _A times, else once. + "_L(__afl_connected ? _A : 1); })"; - cc_params[cc_par_cnt++] = - "-D__AFL_INIT()=" - "do { static volatile const char *_A __attribute__((used,unused)); " - " _A = (const char*)\"" DEFER_SIG - "\"; " + cc_params[cc_par_cnt++] = + "-D__AFL_INIT()=" + "do { static volatile const char *_A __attribute__((used,unused)); " + " _A = (const char*)\"" DEFER_SIG + "\"; " #ifdef __APPLE__ - "__attribute__((visibility(\"default\"))) " - "void _I(void) __asm__(\"___afl_manual_init\"); " + "__attribute__((visibility(\"default\"))) " + "void _I(void) __asm__(\"___afl_manual_init\"); " #else - "__attribute__((visibility(\"default\"))) " - "void _I(void) __asm__(\"__afl_manual_init\"); " + "__attribute__((visibility(\"default\"))) " + "void _I(void) __asm__(\"__afl_manual_init\"); " #endif /* ^__APPLE__ */ - "_I(); } while (0)"; + "_I(); } while (0)"; + + } if (x_set) { |