Merge pull request #1824 from schumilo/dev

Nyx mode - minor changes

README.md

@@ -229,7 +229,7 @@ Thank you! (For people sending pull requests - please add yourself to this list
     Thomas Rooijakkers                    David Carlier
     Ruben ten Hove                        Joey Jiao
     fuzzah                                @intrigus-lgtm
-    Yaakov Saxon
+    Yaakov Saxon                          Sergej Schumilo
   ```
 
 </details>

include/envs.h

@@ -190,6 +190,8 @@ static char *afl_environment_variables[] = {
     "AFL_NO_X86",  // not really an env but we dont want to warn on it
     "AFL_NOOPT",
     "AFL_NYX_AUX_SIZE",
+    "AFL_NYX_DISABLE_SNAPSHOT_MODE",
+    "AFL_NYX_REUSE_SNAPSHOT",
     "AFL_PASSTHROUGH",
     "AFL_PATH",
     "AFL_PERFORMANCE_FILE",

nyx_mode/QEMU_NYX_VERSION

@@ -1 +1 @@
-a09d3ae2e6
+874fa033d1

nyx_mode/README.md

@@ -150,12 +150,12 @@ afl-cmin -i in_dir -o out_dir -X -- ./PACKAGE-DIRECTORY
 
 On each program startup of one the AFL++ tools in Nyx mode, a Nyx VM is spawned, and a bootstrapping procedure is performed inside the VM to prepare the target environment. As a consequence, due to the bootstrapping procedure, the launch performance is much slower compared to other modes. However, this can be optimized by reusing an existing fuzzing snapshot to avoid the slow re-execution of the bootstrap procedure. 
 
-A fuzzing snapshot is automatically created and stored in the output directory at `out_dir/workdir/snapshot/` by the first parent process of `afl-fuzz` if parallel mode is used. To enable this feature, set the path to an existing snapshot directory in the `NYX_REUSE_SNAPSHOT` environment variable and use the tools as usual:
+A fuzzing snapshot is automatically created and stored in the output directory at `out_dir/workdir/snapshot/` by the first parent process of `afl-fuzz` if parallel mode is used. To enable this feature, set the path to an existing snapshot directory in the `AFL_NYX_REUSE_SNAPSHOT` environment variable and use the tools as usual:
 
 ```shell 
 afl-fuzz -i ./in_dir -o ./out_dir -Y -M 0 ./PACKAGE-DIRECTORY
 
-NYX_REUSE_SNAPSHOT=./out_dir/workdir/snapshot/ afl-analyze -i in_file -X  -- ./PACKAGE-DIRECTORY
+AFL_NYX_REUSE_SNAPSHOT=./out_dir/workdir/snapshot/ afl-analyze -i in_file -X  -- ./PACKAGE-DIRECTORY
 ```
 
 
@@ -311,7 +311,7 @@ command:
 ```
 
 If you want to disable fast snapshots (except for crashes), you can simply set
-the `NYX_DISABLE_SNAPSHOT_MODE` environment variable.
+the `AFL_NYX_DISABLE_SNAPSHOT_MODE` environment variable.
 
 ### Nyx crash reports
 
@@ -331,7 +331,7 @@ the header (1408 bytes) and the remaining bytes can be used to transfer crash
 reports (also the `hprintf` feature utilizes the very same shared memory for 
 transferring data). By default a crash report will be truncated to 2688 bytes.
 However, if you want to increase the size of the shared memory region, you can
-set the `NYX_AUX_BUFFER_SIZE` environment variable to a higher value (keep in
+set the `AFL_NYX_AUX_SIZE` environment variable to a higher value (keep in
 mind that this value must be a multiple of 4096).
 
 ### Run AFL++Nyx with a custom agent

src/afl-forkserver.c

@@ -606,23 +606,23 @@ void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv,
 
     }
 
-    if (getenv("NYX_REUSE_SNAPSHOT") != NULL) {
+    if (getenv("AFL_NYX_REUSE_SNAPSHOT") != NULL) {
 
-      if (access(getenv("NYX_REUSE_SNAPSHOT"), F_OK) == -1) {
+      if (access(getenv("AFL_NYX_REUSE_SNAPSHOT"), F_OK) == -1) {
 
-        NYX_PRE_FATAL(fsrv, "NYX_REUSE_SNAPSHOT path does not exist");
+        NYX_PRE_FATAL(fsrv, "AFL_NYX_REUSE_SNAPSHOT path does not exist");
 
       }
 
       /* stupid sanity check to avoid passing an empty or invalid snapshot
        * directory */
       char *snapshot_file_path =
-          alloc_printf("%s/global.state", getenv("NYX_REUSE_SNAPSHOT"));
+          alloc_printf("%s/global.state", getenv("AFL_NYX_REUSE_SNAPSHOT"));
       if (access(snapshot_file_path, R_OK) == -1) {
 
-        NYX_PRE_FATAL(
-            fsrv,
-            "NYX_REUSE_SNAPSHOT path does not contain a valid Nyx snapshot");
+        NYX_PRE_FATAL(fsrv,
+                      "AFL_NYX_REUSE_SNAPSHOT path does not contain a valid "
+                      "Nyx snapshot");
 
       }
 
@@ -634,13 +634,14 @@ void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv,
       char *workdir_snapshot_path =
           alloc_printf("%s/workdir/snapshot", outdir_path_absolute);
       char *reuse_snapshot_path_real =
-          realpath(getenv("NYX_REUSE_SNAPSHOT"), NULL);
+          realpath(getenv("AFL_NYX_REUSE_SNAPSHOT"), NULL);
 
       if (strcmp(workdir_snapshot_path, reuse_snapshot_path_real) == 0) {
 
-        NYX_PRE_FATAL(fsrv,
-                      "NYX_REUSE_SNAPSHOT path is located in current workdir "
-                      "(use another output directory)");
+        NYX_PRE_FATAL(
+            fsrv,
+            "AFL_NYX_REUSE_SNAPSHOT path is located in current workdir "
+            "(use another output directory)");
 
       }
 
@@ -648,7 +649,7 @@ void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv,
       ck_free(workdir_snapshot_path);
 
       fsrv->nyx_handlers->nyx_config_set_reuse_snapshot_path(
-          nyx_config, getenv("NYX_REUSE_SNAPSHOT"));
+          nyx_config, getenv("AFL_NYX_REUSE_SNAPSHOT"));
 
     }
 
@@ -670,7 +671,7 @@ void afl_fsrv_start(afl_forkserver_t *fsrv, char **argv,
         fsrv->nyx_handlers->nyx_get_bitmap_buffer(fsrv->nyx_runner);
 
     fsrv->nyx_handlers->nyx_option_set_reload_mode(
-        fsrv->nyx_runner, getenv("NYX_DISABLE_SNAPSHOT_MODE") == NULL);
+        fsrv->nyx_runner, getenv("AFL_NYX_DISABLE_SNAPSHOT_MODE") == NULL);
     fsrv->nyx_handlers->nyx_option_apply(fsrv->nyx_runner);
 
     fsrv->nyx_handlers->nyx_option_set_timeout(fsrv->nyx_runner, 2, 0);

src/afl-fuzz.c

@@ -302,7 +302,8 @@ static void usage(u8 *argv0, int more_help) {
       "AFL_NYX_AUX_SIZE: size of the Nyx auxiliary buffer. Must be a multiple of 4096.\n"
       "                  Increase this value in case the crash reports are truncated.\n"
       "                  Default value is 4096.\n"
-
+      "AFL_NYX_DISABLE_SNAPSHOT_MODE: disable snapshot mode (must be supported by the agent)\n"
+      "AFL_NYX_REUSE_SNAPSHOT: reuse an existing Nyx root snapshot\n"
       DYN_COLOR
 
       "AFL_PATH: path to AFL support binaries\n"