src/share/vm/runtime/stubRoutines.cpp

rev 7968 : 8074552:  SafeFetch32 and SafeFetchN do not work in error handling
Summary: handle SafeFetch faults in secondary signal handlers
Reviewed-by: dholmes
Contributed-by: Thomas Stuefe

*** 208,219 ****
    ((arraycopy_fn)func)(buffer + alignment, buffer2, 0);
    for (i = 0; i < sizeof(lbuffer); i++) {
      assert(fbuffer[i] == v && fbuffer2[i] == v2, "shouldn't have copied anything");
    }
  }
- #endif
  
  
  void StubRoutines::initialize2() {
    if (_code2 == NULL) {
      ResourceMark rm;
      TraceTime timer("StubRoutines generation 2", TraceStartupTime);
--- 208,247 ----
    ((arraycopy_fn)func)(buffer + alignment, buffer2, 0);
    for (i = 0; i < sizeof(lbuffer); i++) {
      assert(fbuffer[i] == v && fbuffer2[i] == v2, "shouldn't have copied anything");
    }
  }
  
+ // simple test for SafeFetch32
+ static void test_safefetch32() {
+   int dummy = 17;
+   int* const p_invalid = (int*) get_segfault_address();
+   int* const p_valid = &dummy;
+   int result_invalid = SafeFetch32(p_invalid, 0xABC);
+   assert(result_invalid == 0xABC, "SafeFetch32 error");
+   int result_valid = SafeFetch32(p_valid, 0xABC);
+   assert(result_valid == 17, "SafeFetch32 error");
+ }
+ 
+ // simple test for SafeFetchN
+ static void test_safefetchN() {
+ #ifdef _LP64
+   const intptr_t v1 = UCONST64(0xABCD00000000ABCD);
+   const intptr_t v2 = UCONST64(0xDEFD00000000DEFD);
+ #else
+   const intptr_t v1 = 0xABCDABCD;
+   const intptr_t v2 = 0xDEFDDEFD;
+ #endif
+   intptr_t dummy = v1;
+   intptr_t* const p_invalid = (intptr_t*) get_segfault_address();
+   intptr_t* const p_valid = &dummy;
+   intptr_t result_invalid = SafeFetchN(p_invalid, v2);
+   assert(result_invalid == v2, "SafeFetchN error");
+   intptr_t result_valid = SafeFetchN(p_valid, v2);
+   assert(result_valid == v1, "SafeFetchN error");
+ }
+ #endif
  
  void StubRoutines::initialize2() {
    if (_code2 == NULL) {
      ResourceMark rm;
      TraceTime timer("StubRoutines generation 2", TraceStartupTime);
*** 298,307 ****
--- 326,346 ----
    test_arraycopy_func(CAST_FROM_FN_PTR(address, Copy::disjoint_words_atomic), sizeof(HeapWord));
    // Aligned to BytesPerLong
    test_arraycopy_func(CAST_FROM_FN_PTR(address, Copy::aligned_conjoint_words), sizeof(jlong));
    test_arraycopy_func(CAST_FROM_FN_PTR(address, Copy::aligned_disjoint_words), sizeof(jlong));
  
+   // test safefetch routines
+   // Not on Windows 32bit until 8074860 is fixed
+ #if ! (defined(_WIN32) && defined(_M_IX86))
+   if (CanUseSafeFetch32()) {
+     test_safefetch32();
+   }
+   if (CanUseSafeFetchN()) {
+     test_safefetchN();
+   }
+ #endif
+ 
  #endif
  }
  
  
  void stubRoutines_init1() { StubRoutines::initialize1(); }