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/*
american fuzzy lop++ - high-performance binary-only instrumentation
-------------------------------------------------------------------
Originally written by Andrew Griffiths <agriffiths@google.com> and
Michal Zalewski
TCG instrumentation and block chaining support by Andrea Biondo
<andrea.biondo965@gmail.com>
QEMU 3.1.1 port, TCG thread-safety, CompareCoverage and NeverZero
counters by Andrea Fioraldi <andreafioraldi@gmail.com>
Copyright 2015, 2016, 2017 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 code is a shim patched into the separately-distributed source
code of QEMU 3.1.0. It leverages the built-in QEMU tracing functionality
to implement AFL-style instrumentation and to take care of the remaining
parts of the AFL fork server logic.
The resulting QEMU binary is essentially a standalone instrumentation
tool; for an example of how to leverage it for other purposes, you can
have a look at afl-showmap.c.
*/
#include "afl-qemu-common.h"
#include "tcg.h"
void HELPER(afl_entry_routine)(CPUArchState *env) {
afl_forkserver(ENV_GET_CPU(env));
}
void HELPER(afl_compcov_16)(target_ulong cur_loc, target_ulong arg1,
target_ulong arg2) {
register uintptr_t idx = cur_loc;
if ((arg1 & 0xff00) == (arg2 & 0xff00)) { INC_AFL_AREA(idx); }
}
void HELPER(afl_compcov_32)(target_ulong cur_loc, target_ulong arg1,
target_ulong arg2) {
register uintptr_t idx = cur_loc;
if ((arg1 & 0xff000000) == (arg2 & 0xff000000)) {
INC_AFL_AREA(idx + 2);
if ((arg1 & 0xff0000) == (arg2 & 0xff0000)) {
INC_AFL_AREA(idx + 1);
if ((arg1 & 0xff00) == (arg2 & 0xff00)) { INC_AFL_AREA(idx); }
}
}
}
void HELPER(afl_compcov_64)(target_ulong cur_loc, target_ulong arg1,
target_ulong arg2) {
register uintptr_t idx = cur_loc;
if ((arg1 & 0xff00000000000000) == (arg2 & 0xff00000000000000)) {
INC_AFL_AREA(idx + 6);
if ((arg1 & 0xff000000000000) == (arg2 & 0xff000000000000)) {
INC_AFL_AREA(idx + 5);
if ((arg1 & 0xff0000000000) == (arg2 & 0xff0000000000)) {
INC_AFL_AREA(idx + 4);
if ((arg1 & 0xff00000000) == (arg2 & 0xff00000000)) {
INC_AFL_AREA(idx + 3);
if ((arg1 & 0xff000000) == (arg2 & 0xff000000)) {
INC_AFL_AREA(idx + 2);
if ((arg1 & 0xff0000) == (arg2 & 0xff0000)) {
INC_AFL_AREA(idx + 1);
if ((arg1 & 0xff00) == (arg2 & 0xff00)) { INC_AFL_AREA(idx); }
}
}
}
}
}
}
}
void HELPER(afl_cmplog_16)(target_ulong cur_loc, target_ulong arg1,
target_ulong arg2) {
register uintptr_t k = (uintptr_t)cur_loc;
u32 hits = __afl_cmp_map->headers[k].hits;
__afl_cmp_map->headers[k].hits = hits + 1;
// if (!__afl_cmp_map->headers[k].cnt)
// __afl_cmp_map->headers[k].cnt = __afl_cmp_counter++;
__afl_cmp_map->headers[k].shape = 1;
//__afl_cmp_map->headers[k].type = CMP_TYPE_INS;
hits &= CMP_MAP_H - 1;
__afl_cmp_map->log[k][hits].v0 = arg1;
__afl_cmp_map->log[k][hits].v1 = arg2;
}
void HELPER(afl_cmplog_32)(target_ulong cur_loc, target_ulong arg1,
target_ulong arg2) {
register uintptr_t k = (uintptr_t)cur_loc;
u32 hits = __afl_cmp_map->headers[k].hits;
__afl_cmp_map->headers[k].hits = hits + 1;
__afl_cmp_map->headers[k].shape = 3;
hits &= CMP_MAP_H - 1;
__afl_cmp_map->log[k][hits].v0 = arg1;
__afl_cmp_map->log[k][hits].v1 = arg2;
}
void HELPER(afl_cmplog_64)(target_ulong cur_loc, target_ulong arg1,
target_ulong arg2) {
register uintptr_t k = (uintptr_t)cur_loc;
u32 hits = __afl_cmp_map->headers[k].hits;
__afl_cmp_map->headers[k].hits = hits + 1;
__afl_cmp_map->headers[k].shape = 7;
hits &= CMP_MAP_H - 1;
__afl_cmp_map->log[k][hits].v0 = arg1;
__afl_cmp_map->log[k][hits].v1 = arg2;
}
#include <sys/mman.h>
static int area_is_mapped(void *ptr, size_t len) {
char *p = ptr;
char *page = (char *)((uintptr_t)p & ~(sysconf(_SC_PAGE_SIZE) - 1));
int r = msync(page, (p - page) + len, MS_ASYNC);
if (r < 0) return errno != ENOMEM;
return 1;
}
void HELPER(afl_cmplog_rtn)(CPUX86State *env) {
#if defined(TARGET_X86_64)
void *ptr1 = g2h(env->regs[R_EDI]);
void *ptr2 = g2h(env->regs[R_ESI]);
#elif defined(TARGET_I386)
target_ulong *stack = g2h(env->regs[R_ESP]);
if (!area_is_mapped(stack, sizeof(target_ulong) * 2)) return;
// when this hook is executed, the retaddr is not on stack yet
void *ptr1 = g2h(stack[0]);
void *ptr2 = g2h(stack[1]);
#else
// dumb code to make it compile
void *ptr1 = NULL;
void *ptr2 = NULL;
return;
#endif
if (!area_is_mapped(ptr1, 32) || !area_is_mapped(ptr2, 32)) return;
uintptr_t k = (uintptr_t)env->eip;
k = (k >> 4) ^ (k << 8);
k &= CMP_MAP_W - 1;
__afl_cmp_map->headers[k].type = CMP_TYPE_RTN;
u32 hits = __afl_cmp_map->headers[k].hits;
__afl_cmp_map->headers[k].hits = hits + 1;
__afl_cmp_map->headers[k].shape = 31;
hits &= CMP_MAP_RTN_H - 1;
__builtin_memcpy(((struct cmpfn_operands *)__afl_cmp_map->log[k])[hits].v0,
ptr1, 32);
__builtin_memcpy(((struct cmpfn_operands *)__afl_cmp_map->log[k])[hits].v1,
ptr2, 32);
}
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