stdout/stderr fix

4 files changed, 14 insertions, 17 deletions

diff --git a/AUTHORS b/AUTHORS
index 4016c17..cc113dc 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -2,5 +2,5 @@ This code was developed as part of a project with the Cisco Talos VULNDEV Team
 
 Authors: 
   Aleksandar Nikolic <anikolich@sourcefire.com> 
-  van Hauser <vh@thc.org>
+  Marc "van Hauser" Heuse <mh@mh-sec.de> || <vh@thc.org>
 
diff --git a/CHANGES b/CHANGES
index b9d86e3..550a845 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2,6 +2,7 @@ Changelog
 =========
 
 vh@thc.org / https://github.com/vanhauser-thc/afl-dyninst:
+ - Fix for programs that were unable to print to stdout after instrumentation
  - added -f switch to fix a bug in dyninst where sometimes the edi/rdi
    register is not saved which is used in the instrumentation function
    when a function is using edi/rdi for parameter passing
diff --git a/afl-fuzz.sh b/afl-fuzz.sh
index c9986c6..bb10a95 100755
--- a/afl-fuzz.sh
+++ b/afl-fuzz.sh
@@ -2,5 +2,8 @@
 test -z "$1" -o "$1" = "-h" && { echo Syntax: $0 afl-fuzz-options ; echo sets the afl-dyninst environment variables ; exit 1 ; }
 export AFL_SKIP_BIN_CHECK=1
 export DYNINSTAPI_RT_LIB=/usr/local/lib/libdyninstAPI_RT.so
-#export AFL_PRELOAD=./desock.so
+export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:.
+export AFL_EXIT_WHEN_DONE=1
+#export AFL_TMPDIR=/run/$$
+#export AFL_PRELOAD=./desock.so:./libdislocator/libdislocator.so
 afl-fuzz $*
diff --git a/libAflDyninst.cpp b/libAflDyninst.cpp
index ef9d046..3374010 100644
--- a/libAflDyninst.cpp
+++ b/libAflDyninst.cpp
@@ -22,36 +22,39 @@ static unsigned short prev_id;
 static long saved_di;
 register long rdi asm("di");    // the warning is fine - we need the warning because of a bug in dyninst
 
+#define PRINT_ERROR(string) write(2, string, strlen(string))
+
 void initAflForkServer() {
+  // we can not use fprint* stdout/stderr functions here, it fucks up some programs
   char *shm_env_var = getenv(SHM_ENV_VAR);
 
   if (!shm_env_var) {
-    printf("Error getting shm\n");
+    PRINT_ERROR("Error getting shm\n");
     return;
   }
   shm_id = atoi(shm_env_var);
   trace_bits = (u8 *) shmat(shm_id, NULL, 0);
   if (trace_bits == (u8 *) - 1) {
-    perror("shmat");
+    PRINT_ERROR("Error: shmat\n");
     return;
   }
   // enter fork() server thyme!
   int n = write(FORKSRV_FD + 1, &__afl_temp_data, 4);
 
   if (n != 4) {
-    printf("Error writting fork server\n");
+    PRINT_ERROR("Error writting fork server\n");
     return;
   }
   while (1) {
     n = read(FORKSRV_FD, &__afl_temp_data, 4);
     if (n != 4) {
-      printf("Error reading fork server %x\n", __afl_temp_data);
+      PRINT_ERROR("Error reading fork server\n");
       return;
     }
 
     __afl_fork_pid = fork();
     if (__afl_fork_pid < 0) {
-      printf("Error on fork()\n");
+      PRINT_ERROR("Error on fork()\n");
       return;
     }
     if (__afl_fork_pid == 0) {
@@ -81,18 +84,8 @@ void bbCallback(unsigned short id) {
 
 void save_rdi() {
   saved_di = rdi;
-/*
-  asm("pop %rax"); // take care of rip
-  asm("push %rdi");
-  asm("push %rax");
-*/
 }
 
 void restore_rdi() {
   rdi = saved_di;
-/*
-  asm("pop %rax"); // take care of rip
-  asm("pop %rdi");
-  asm("push %rax");
-*/
 }