uc_emu_start() report error on illegal instruction at the output

.gitignore

@@ -81,3 +81,5 @@ bindings/python/build/
 config.log
 
 regress/map_crash
+regress/sigill
+regress/sigill2

qemu/target-i386/unicorn.c

@@ -938,6 +938,16 @@ int x86_uc_machine_init(struct uc_struct *uc)
     return machine_initialize(uc);
 }
 
+static bool x86_stop_interrupt(int intno)
+{
+    switch(intno) {
+        default:
+            return false;
+        case EXCP06_ILLOP:
+            return true;
+    }
+}
+
 void pc_machine_init(struct uc_struct *uc);
 
 __attribute__ ((visibility ("default")))
@@ -954,5 +964,6 @@ void x86_uc_init(struct uc_struct* uc)
     uc->reg_reset = x86_reg_reset;
     uc->release = x86_release;
     uc->set_pc = x86_set_pc;
+    uc->stop_interrupt = x86_stop_interrupt;
     uc_common_init(uc);
 }

regress/Makefile

@@ -1,7 +1,7 @@
 CFLAGS += -I../include
 LDFLAGS = -L.. -lunicorn
 
-TESTS = map_crash sigill
+TESTS = map_crash sigill sigill2
 
 all: $(TESTS)
 

regress/sigill2.c

@@ -0,0 +1,29 @@
+#include <unicorn/unicorn.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#define UC_BUG_WRITE_SIZE 128
+#define UC_BUG_WRITE_ADDR 0x2000
+
+int main()
+{
+    int size;
+    uint8_t *buf;
+    uch uh;
+    uch uh_trap;
+    uc_err err = uc_open (UC_ARCH_X86, UC_MODE_64, &uh);
+    if (err) {
+        fprintf (stderr, "Cannot initialize unicorn\n");
+        return 1;
+    }
+    size = UC_BUG_WRITE_SIZE;
+    if (!uc_mem_map (uh, UC_BUG_WRITE_ADDR, size)) {
+        uc_mem_write (uh, UC_BUG_WRITE_ADDR,
+            (const uint8_t*)"\xff\xff\xff\xff\xff\xff\xff\xff", 8);
+    }
+    err = uc_emu_start (uh, UC_BUG_WRITE_ADDR, UC_BUG_WRITE_ADDR+8, 0, 1);
+    uc_close (&uh);
+    printf ("Error = %u (%s)\n", err, uc_strerror(err));
+    return err? -1: 0;
+}

uc.c

@@ -410,6 +410,11 @@ uc_err uc_emu_start(uch handle, uint64_t begin, uint64_t until, uint64_t timeout
         // invalid handle
         return UC_ERR_UCH;
 
+    // reset the counter
+    uc->emu_counter = 0;
+    uc->stop_request = false;
+    uc->invalid_error = UC_ERR_OK;
+
     switch(uc->arch) {
         default:
             break;
@@ -474,11 +479,6 @@ uc_err uc_emu_start(uch handle, uint64_t begin, uint64_t until, uint64_t timeout
     // emulation is done
     uc->emulation_done = true;
 
-    // reset the counter
-    uc->emu_counter = 0;
-    uc->stop_request = false;
-    uc->invalid_error = UC_ERR_OK;
-
     return uc->invalid_error;
 }