make llvm_mode pcguard instrumentation collision free
MODIFY
docs/Changelog.md
docs/Changelog.md
@@ -31,6 +31,8 @@ sending a mail to <afl-users+subscribe@googlegroups.com>.
as it is faster and provides better coverage. The original afl
instrumentation can be set via AFL_LLVM_INSTRUMENT=AFL. This is
automatically done when the WHITELIST feature is used.
+ - PCGUARD mode is now even better because we made it collision free - plus
+ it has a fixed map size, so it is also faster! :)
- some targets want a ld variant for LD that is not gcc/clang but ld,
added afl-ld-lto to solve this
- lowered minimum required llvm version to 3.4 (except LLVMInsTrim, which

MODIFY
llvm_mode/afl-llvm-rt.o.c
llvm_mode/afl-llvm-rt.o.c
@@ -183,6 +183,9 @@ static void __afl_map_shm(void) {
if (__afl_final_loc) {
+ if (__afl_final_loc % 8)
+ __afl_final_loc = (((__afl_final_loc + 7) >> 3) << 3);
+
__afl_map_size = __afl_final_loc;
if (__afl_final_loc > MAP_SIZE) {
@@ -871,7 +874,7 @@ void __sanitizer_cov_trace_pc_guard_init(uint32_t *start, uint32_t *stop) {
while (start < stop) {
if (R(100) < inst_ratio)
- *start = R(MAP_SIZE - 1) + 1;
+ *start = ++__afl_final_loc;
else
*start = 0;

MODIFY
src/afl-forkserver.c
src/afl-forkserver.c
@@ -569,7 +569,7 @@ void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv,
if (unlikely(tmp_map_size % 8)) {
// should not happen
- WARNF("Target reported non-aligned map size of %ud", tmp_map_size);
+ WARNF("Target reported non-aligned map size of %u", tmp_map_size);
tmp_map_size = (((tmp_map_size + 8) >> 3) << 3);
}

make llvm_mode pcguard instrumentation collision free