afl-showmap: Start a only a single fork server (#1718)

A forkserver is started by afl_fsrv_get_mapsize() when dynamically
finding the map size.  When an input directory option is specified a
second fork server was also started.  This commit re-arranges the inits
for several forkserver struct members so that we can re-use the server
started by the get_mapsize() call when not in coresight/qemu/unicorn
modes and just start the server otherwise.

1 files changed, 16 insertions, 13 deletions

diff --git a/src/afl-showmap.c b/src/afl-showmap.c
index f60acb2d..9c029035 100644
--- a/src/afl-showmap.c
+++ b/src/afl-showmap.c
@@ -1421,6 +1421,14 @@ int main(int argc, char **argv_orig, char **envp) {
     // If @@ are in the target args, replace them and also set use_stdin=false.
     detect_file_args(argv + optind, stdin_file, &fsrv->use_stdin);
 
+    fsrv->dev_null_fd = open("/dev/null", O_RDWR);
+    if (fsrv->dev_null_fd < 0) { PFATAL("Unable to open /dev/null"); }
+
+    fsrv->out_file = stdin_file;
+    fsrv->out_fd =
+        open(stdin_file, O_RDWR | O_CREAT | O_EXCL, DEFAULT_PERMISSION);
+    if (fsrv->out_fd < 0) { PFATAL("Unable to create '%s'", stdin_file); }
+
   } else {
 
     // If @@ are in the target args, replace them and also set use_stdin=false.
@@ -1588,6 +1596,14 @@ int main(int argc, char **argv_orig, char **envp) {
 
     fsrv->map_size = map_size;
 
+  } else {
+
+    afl_fsrv_start(fsrv, use_argv, &stop_soon,
+                   (get_afl_env("AFL_DEBUG_CHILD") ||
+                    get_afl_env("AFL_DEBUG_CHILD_OUTPUT"))
+                       ? 1
+                       : 0);
+
   }
 
   if (in_dir || in_filelist) {
@@ -1617,9 +1633,6 @@ int main(int argc, char **argv_orig, char **envp) {
 
     if (getenv("AFL_DEBUG_GDB")) wait_for_gdb = true;
 
-    fsrv->dev_null_fd = open("/dev/null", O_RDWR);
-    if (fsrv->dev_null_fd < 0) { PFATAL("Unable to open /dev/null"); }
-
     if (in_filelist) {
 
       if (!be_quiet) ACTF("Reading from file list '%s'...", in_filelist);
@@ -1666,10 +1679,6 @@ int main(int argc, char **argv_orig, char **envp) {
     }
 
     atexit(at_exit_handler);
-    fsrv->out_file = stdin_file;
-    fsrv->out_fd =
-        open(stdin_file, O_RDWR | O_CREAT | O_EXCL, DEFAULT_PERMISSION);
-    if (fsrv->out_fd < 0) { PFATAL("Unable to create '%s'", out_file); }
 
     if (get_afl_env("AFL_DEBUG")) {
 
@@ -1685,12 +1694,6 @@ int main(int argc, char **argv_orig, char **envp) {
 
     }
 
-    afl_fsrv_start(fsrv, use_argv, &stop_soon,
-                   (get_afl_env("AFL_DEBUG_CHILD") ||
-                    get_afl_env("AFL_DEBUG_CHILD_OUTPUT"))
-                       ? 1
-                       : 0);
-
     map_size = fsrv->map_size;
 
     if (fsrv->support_shmem_fuzz && !fsrv->use_shmem_fuzz)