Merge pull request #59 from kokkonisd/master

Snapshot mode: fix incompatibility with libcompcov.so

Author: vanhauser-thc

accel/tcg/cpu-exec.c

@@ -176,12 +176,18 @@ static void collect_memory_snapshot(void) {
   char *line = NULL;
   size_t len = 0;
   ssize_t read;
+  uint64_t afl_shm_inode = 0;
+  char *afl_shm_id_str = getenv(SHM_ENV_VAR);
 
   fp = fopen("/proc/self/maps", "r");
   if (fp == NULL) {
     fprintf(stderr, "[AFL] ERROR: cannot open /proc/self/maps\n");
     exit(1);
   }
+
+  if (afl_shm_id_str) {
+    afl_shm_inode = atoi(afl_shm_id_str);
+  }
 
   size_t memory_snapshot_allocd = 32;
   if (!lkm_snapshot)
@@ -208,6 +214,11 @@ static void collect_memory_snapshot(void) {
     if (page_check_range(h2g(min), max - min, flags) == -1)
         continue;
 
+    // When `libcompcov.so` is used, the shared memory used to track coverage
+    // is picked up here. Obviously, we don't want to reset that, as that
+    // would erase coverage tracking, so we skip it.
+    if (afl_shm_id_str && inode == afl_shm_inode) continue;
+
     if (lkm_snapshot) {
 
       afl_snapshot_include_vmrange((void*)min, (void*)max);