[MSAN] Add support for big endian byte order to the test ptrtoint

[slthakur]

Summary

Read the poisoned/non-poisoned bytes correctly for big endian targets.

[eugenis]

Could you check if this works for you:

TEST(MemorySanitizer, ptrtoint) {

// Test that shadow is propagated through pointer-to-integer conversion.                                                      
unsigned char c = 0;
__msan_poison(&c, 1);
uintptr_t u = (uintptr_t)c << 8;
EXPECT_NOT_POISONED(u & 0xFF00FF);
EXPECT_POISONED(u & 0xFF00);

break_optimization(&u);
void* p = (void*)u;

break_optimization(&p);
EXPECT_POISONED(p);
EXPECT_NOT_POISONED(((uintptr_t)p) & 0xFF00FF);
EXPECT_POISONED(((uintptr_t)p) & 0xFF00);

}

[slthakur]

Hi @eugenis

This test works for me for both byte orders.

Thanks,
Sagar

[eugenis]

r260749

lib/msan/tests/msan_test.cc

 #include <stdlib.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <wchar.h>
 #include <math.h>
 
 #include <arpa/inet.h>
 #include <dlfcn.h>
+#include <endian.h>
 #include <grp.h>
 #include <unistd.h>
 #include <link.h>
 #include <limits.h>
 #include <sys/time.h>
 #include <poll.h>
 #include <sys/types.h>
 #include <sys/stat.h>
TEST(MemorySanitizer, Invoke) {
   EXPECT_POISONED(*GetPoisoned<int>());
   EXPECT_POISONED(ReturnPoisoned<S4>());
 }
 
 TEST(MemorySanitizer, ptrtoint) {
   // Test that shadow is propagated through pointer-to-integer conversion.
   void* p = (void*)0xABCD;
   __msan_poison(((char*)&p) + 1, sizeof(p));
+#if BYTE_ORDER == __LITTLE_ENDIAN
   EXPECT_NOT_POISONED((((uintptr_t)p) & 0xFF) == 0);
+#else
+  EXPECT_NOT_POISONED((((uintptr_t)p) & 0xFF00000000000000) == 0);
+#endif
 
   void* q = (void*)0xABCD;
   __msan_poison(&q, sizeof(q) - 1);
+#if BYTE_ORDER == __LITTLE_ENDIAN
   EXPECT_POISONED((((uintptr_t)q) & 0xFF) == 0);
+#else
+  EXPECT_POISONED((((uintptr_t)q) & 0xFFFFFFFFFFFFFF00) == 0);
+#endif
 }
 
 static void vaargsfn2(int guard, ...) {
   va_list vl;
   va_start(vl, guard);
   EXPECT_NOT_POISONED(va_arg(vl, int));
   EXPECT_NOT_POISONED(va_arg(vl, int));
   EXPECT_NOT_POISONED(va_arg(vl, int));