Add utils (#62)

* add utils file
* user only guard.

include/libafl/utils.h

@@ -0,0 +1,7 @@
+#pragma once
+
+#include "qemu/osdep.h"
+
+#ifndef CONFIG_USER_ONLY
+uint8_t* libafl_paddr2host(CPUState* cpu, hwaddr addr, bool is_write);
+#endif

libafl/meson.build

@@ -1,7 +1,8 @@
 specific_ss.add(files(
   'exit.c',
   'hook.c',
-  'jit.c'
+  'jit.c',
+  'utils.c',
 ))
 
 specific_ss.add(when: 'CONFIG_SOFTMMU', if_true: [files(

libafl/utils.c

@@ -0,0 +1,24 @@
+#include "qemu/osdep.h"
+
+#ifndef CONFIG_USER_ONLY
+#include "exec/memory.h"
+#include "qemu/rcu.h"
+#include "cpu.h"
+
+#include "libafl/utils.h"
+
+uint8_t* libafl_paddr2host(CPUState* cpu, hwaddr addr, bool is_write)
+{
+    if (addr == -1) {
+        return NULL;
+    }
+
+    hwaddr xlat;
+    MemoryRegion* mr;
+    WITH_RCU_READ_LOCK_GUARD() {
+        mr = address_space_translate(cpu->as, addr, &xlat, NULL, is_write, MEMTXATTRS_UNSPECIFIED);
+    }
+
+    return qemu_map_ram_ptr(mr->ram_block, xlat);
+}
+#endif