diff options
| -rw-r--r-- | docs/INSTALL.md | 35 | ||||
| -rw-r--r-- | src/afl-cc.c | 12 |
2 files changed, 45 insertions, 2 deletions
diff --git a/docs/INSTALL.md b/docs/INSTALL.md index e3c06c9d..80d452f7 100644 --- a/docs/INSTALL.md +++ b/docs/INSTALL.md @@ -103,6 +103,41 @@ The llvm instrumentation requires a fully-operational installation of clang. The comes with Xcode is missing some of the essential headers and helper tools. See README.llvm.md for advice on how to build the compiler from scratch. +MacOS X supports SYSV shared memory used by AFL's instrumentation, but the +default settings aren't usable with AFL++. The default settings on 10.14 seem +to be: + +```bash +$ ipcs -M +IPC status from <running system> as of XXX +shminfo: + shmmax: 4194304 (max shared memory segment size) + shmmin: 1 (min shared memory segment size) + shmmni: 32 (max number of shared memory identifiers) + shmseg: 8 (max shared memory segments per process) + shmall: 1024 (max amount of shared memory in pages) +``` + +To temporarily change your settings to something minimally usable with AFL++, +run these commands as root: + +```bash +sysctl kern.sysv.shmmax=8388608 +sysctl kern.sysv.shmall=4096 +``` + +If you're running more than one instance of AFL you likely want to make `shmall` +bigger and increase `shmseg` as well: + +```bash +sysctl kern.sysv.shmmax=8388608 +sysctl kern.sysv.shmseg=48 +sysctl kern.sysv.shmall=98304 +``` + +See http://www.spy-hill.com/help/apple/SharedMemory.html for documentation for +these settings and how to make them permanent. + ## 4. Linux or *BSD on non-x86 systems Standard build will fail on non-x86 systems, but you should be able to diff --git a/src/afl-cc.c b/src/afl-cc.c index 09009334..c1050355 100644 --- a/src/afl-cc.c +++ b/src/afl-cc.c @@ -1574,7 +1574,12 @@ int main(int argc, char **argv, char **envp) { else if (have_gcc_plugin) compiler_mode = GCC_PLUGIN; else if (have_gcc) - compiler_mode = GCC; + #ifdef __APPLE__ + // on OSX clang masquerades as GCC + compiler_mode = CLANG; + #else + compiler_mode = GCC; + #endif else if (have_lto) compiler_mode = LTO; else @@ -1596,7 +1601,10 @@ int main(int argc, char **argv, char **envp) { } - if (compiler_mode == CLANG) { instrument_mode = INSTRUMENT_CLANG; } + if (compiler_mode == CLANG) { + instrument_mode = INSTRUMENT_CLANG; + setenv(CLANG_ENV_VAR, "1", 1); // used by afl-as + } if (argc < 2 || strncmp(argv[1], "-h", 2) == 0) { |