From a9c71d1d91530ec9bb6191fbee2d7afb0f0c5108 Mon Sep 17 00:00:00 2001 From: m5cn9itjr <295305452@qq.com> Date: Wed, 16 Oct 2024 20:29:54 +0800 Subject: [PATCH] ADD file via upload --- afl-llvm-rt.o.c | 314 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 314 insertions(+) create mode 100644 afl-llvm-rt.o.c diff --git a/afl-llvm-rt.o.c b/afl-llvm-rt.o.c new file mode 100644 index 0000000..1c0b40e --- /dev/null +++ b/afl-llvm-rt.o.c @@ -0,0 +1,314 @@ +/* + Copyright 2015 Google LLC 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 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/* + american fuzzy lop - LLVM instrumentation bootstrap + --------------------------------------------------- + + Written by Laszlo Szekeres and + Michal Zalewski + + LLVM integration design comes from Laszlo Szekeres. + + This code is the rewrite of afl-as.h's main_payload. +*/ + +#include "../android-ashmem.h" +#include "../config.h" +#include "../types.h" + +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +/* This is a somewhat ugly hack for the experimental 'trace-pc-guard' mode. + Basically, we need to make sure that the forkserver is initialized after + the LLVM-generated runtime initialization pass, not before. */ + +#ifdef USE_TRACE_PC +# define CONST_PRIO 5 +#else +# define CONST_PRIO 0 +#endif /* ^USE_TRACE_PC */ + + +/* Globals needed by the injected instrumentation. The __afl_area_initial region + is used for instrumentation output before __afl_map_shm() has a chance to run. + It will end up as .comm, so it shouldn't be too wasteful. */ + +u8 __afl_area_initial[MAP_SIZE]; +u8* __afl_area_ptr = __afl_area_initial; + +__thread u32 __afl_prev_loc; + + +/* Running in persistent mode? */ + +static u8 is_persistent; + + +/* SHM setup. */ + +static void __afl_map_shm(void) { + + u8 *id_str = getenv(SHM_ENV_VAR); + + /* If we're running under AFL, attach to the appropriate region, replacing the + early-stage __afl_area_initial region that is needed to allow some really + hacky .init code to work correctly in projects such as OpenSSL. */ + + if (id_str) { + + u32 shm_id = atoi(id_str); + + __afl_area_ptr = shmat(shm_id, NULL, 0); + + /* Whooooops. */ + + if (__afl_area_ptr == (void *)-1) _exit(1); + + /* Write something into the bitmap so that even with low AFL_INST_RATIO, + our parent doesn't give up on us. */ + + __afl_area_ptr[0] = 1; + + } + +} + + +/* Fork server logic. */ + +static void __afl_start_forkserver(void) { + + static u8 tmp[4]; + s32 child_pid; + + u8 child_stopped = 0; + + /* Phone home and tell the parent that we're OK. If parent isn't there, + assume we're not running in forkserver mode and just execute program. */ + + if (write(FORKSRV_FD + 1, tmp, 4) != 4) return; + + while (1) { + + u32 was_killed; + int status; + + /* Wait for parent by reading from the pipe. Abort if read fails. */ + + if (read(FORKSRV_FD, &was_killed, 4) != 4) _exit(1); + + /* If we stopped the child in persistent mode, but there was a race + condition and afl-fuzz already issued SIGKILL, write off the old + process. */ + + if (child_stopped && was_killed) { + child_stopped = 0; + if (waitpid(child_pid, &status, 0) < 0) _exit(1); + } + + if (!child_stopped) { + + /* Once woken up, create a clone of our process. */ + + child_pid = fork(); + if (child_pid < 0) _exit(1); + + /* In child process: close fds, resume execution. */ + + if (!child_pid) { + + close(FORKSRV_FD); + close(FORKSRV_FD + 1); + return; + + } + + } else { + + /* Special handling for persistent mode: if the child is alive but + currently stopped, simply restart it with SIGCONT. */ + + kill(child_pid, SIGCONT); + child_stopped = 0; + + } + + /* In parent process: write PID to pipe, then wait for child. */ + + if (write(FORKSRV_FD + 1, &child_pid, 4) != 4) _exit(1); + + if (waitpid(child_pid, &status, is_persistent ? WUNTRACED : 0) < 0) + _exit(1); + + /* In persistent mode, the child stops itself with SIGSTOP to indicate + a successful run. In this case, we want to wake it up without forking + again. */ + + if (WIFSTOPPED(status)) child_stopped = 1; + + /* Relay wait status to pipe, then loop back. */ + + if (write(FORKSRV_FD + 1, &status, 4) != 4) _exit(1); + + } + +} + + +/* A simplified persistent mode handler, used as explained in README.llvm. */ + +int __afl_persistent_loop(unsigned int max_cnt) { + + static u8 first_pass = 1; + static u32 cycle_cnt; + + if (first_pass) { + + /* Make sure that every iteration of __AFL_LOOP() starts with a clean slate. + On subsequent calls, the parent will take care of that, but on the first + iteration, it's our job to erase any trace of whatever happened + before the loop. */ + + if (is_persistent) { + + memset(__afl_area_ptr, 0, MAP_SIZE); + __afl_area_ptr[0] = 1; + __afl_prev_loc = 0; + } + + cycle_cnt = max_cnt; + first_pass = 0; + return 1; + + } + + if (is_persistent) { + + if (--cycle_cnt) { + + raise(SIGSTOP); + + __afl_area_ptr[0] = 1; + __afl_prev_loc = 0; + + return 1; + + } else { + + /* When exiting __AFL_LOOP(), make sure that the subsequent code that + follows the loop is not traced. We do that by pivoting back to the + dummy output region. */ + + __afl_area_ptr = __afl_area_initial; + + } + + } + + return 0; + +} + + +/* This one can be called from user code when deferred forkserver mode + is enabled. */ + +void __afl_manual_init(void) { + + static u8 init_done; + + if (!init_done) { + + __afl_map_shm(); + __afl_start_forkserver(); + init_done = 1; + + } + +} + + +/* Proper initialization routine. */ + +__attribute__((constructor(CONST_PRIO))) void __afl_auto_init(void) { + + is_persistent = !!getenv(PERSIST_ENV_VAR); + + if (getenv(DEFER_ENV_VAR)) return; + + __afl_manual_init(); + +} + + +/* The following stuff deals with supporting -fsanitize-coverage=trace-pc-guard. + It remains non-operational in the traditional, plugin-backed LLVM mode. + For more info about 'trace-pc-guard', see README.llvm. + + The first function (__sanitizer_cov_trace_pc_guard) is called back on every + edge (as opposed to every basic block). */ + +void __sanitizer_cov_trace_pc_guard(uint32_t* guard) { + __afl_area_ptr[*guard]++; +} + + +/* Init callback. Populates instrumentation IDs. Note that we're using + ID of 0 as a special value to indicate non-instrumented bits. That may + still touch the bitmap, but in a fairly harmless way. */ + +void __sanitizer_cov_trace_pc_guard_init(uint32_t* start, uint32_t* stop) { + + u32 inst_ratio = 100; + u8* x; + + if (start == stop || *start) return; + + x = getenv("AFL_INST_RATIO"); + if (x) inst_ratio = atoi(x); + + if (!inst_ratio || inst_ratio > 100) { + fprintf(stderr, "[-] ERROR: Invalid AFL_INST_RATIO (must be 1-100).\n"); + abort(); + } + + /* Make sure that the first element in the range is always set - we use that + to avoid duplicate calls (which can happen as an artifact of the underlying + implementation in LLVM). */ + + *(start++) = R(MAP_SIZE - 1) + 1; + + while (start < stop) { + + if (R(100) < inst_ratio) *start = R(MAP_SIZE - 1) + 1; + else *start = 0; + + start++; + + } + +}