[asan] initialize kHighMemEnd at startup (instead of at compile time) to simplify further changes for various address space layouts. Fix asan_allocator2 for PowerPC (tested on 44-bit address space)

llvm-svn: 173260

compiler-rt/lib/asan/asan_allocator2.cc

@@ -57,7 +57,11 @@ struct AsanMapUnmapCallback {
 };
 
 #if SANITIZER_WORDSIZE == 64
+#if defined(__powerpc64__)
+const uptr kAllocatorSpace =  0xa0000000000ULL;
+#else
 const uptr kAllocatorSpace = 0x600000000000ULL;
+#endif
 const uptr kAllocatorSize  =  0x10000000000ULL;  // 1T.
 typedef DefaultSizeClassMap SizeClassMap;
 typedef SizeClassAllocator64<kAllocatorSpace, kAllocatorSize, 0 /*metadata*/,

compiler-rt/lib/asan/asan_mapping.h

@@ -43,20 +43,9 @@ extern SANITIZER_INTERFACE_ATTRIBUTE uptr __asan_mapping_offset;
 #endif  // ASAN_FLEXIBLE_MAPPING_AND_OFFSET
 
 #define SHADOW_GRANULARITY (1ULL << SHADOW_SCALE)
-#define MEM_TO_SHADOW(mem) (((mem) >> SHADOW_SCALE) | (SHADOW_OFFSET))
+#define MEM_TO_SHADOW(mem) (((mem) >> SHADOW_SCALE) + (SHADOW_OFFSET))
 #define SHADOW_TO_MEM(shadow) (((shadow) - SHADOW_OFFSET) << SHADOW_SCALE)
 
-#if SANITIZER_WORDSIZE == 64
-# if defined(__powerpc64__)
-  static const uptr kHighMemEnd = 0x00000fffffffffffUL;
-# else
-  static const uptr kHighMemEnd = 0x00007fffffffffffUL;
-# endif
-#else  // SANITIZER_WORDSIZE == 32
-  static const uptr kHighMemEnd = 0xffffffff;
-#endif  // SANITIZER_WORDSIZE
-
-
 #define kLowMemBeg      0
 #define kLowMemEnd      (SHADOW_OFFSET ? SHADOW_OFFSET - 1 : 0)
 
@@ -78,6 +67,8 @@ extern SANITIZER_INTERFACE_ATTRIBUTE uptr __asan_mapping_offset;
 
 namespace __asan {
 
+extern uptr kHighMemEnd;  // Initialized in __asan_init.
+
 static inline bool AddrIsInLowMem(uptr a) {
   return a < kLowMemEnd;
 }

compiler-rt/lib/asan/asan_rtl.cc

@@ -164,6 +164,7 @@ void InitializeFlags(Flags *f, const char *env) {
 int asan_inited;
 bool asan_init_is_running;
 void (*death_callback)(void);
+uptr kHighMemEnd;
 
 // -------------------------- Misc ---------------- {{{1
 void ShowStatsAndAbort() {
@@ -263,6 +264,24 @@ static void asan_atexit() {
   __asan_print_accumulated_stats();
 }
 
+static void InitializeHighMemEnd() {
+#if SANITIZER_WORDSIZE == 64
+# if defined(__powerpc64__)
+  // FIXME:
+  // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
+  // We somehow need to figure our which one we are using now and choose
+  // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
+  // Note that with 'ulimit -s unlimited' the stack is moved away from the top
+  // of the address space, so simply checking the stack address is not enough.
+  kHighMemEnd = (1ULL << 44) - 1;  // 0x00000fffffffffffUL
+# else
+  kHighMemEnd = (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
+# endif
+#else  // SANITIZER_WORDSIZE == 32
+  kHighMemEnd = (1ULL << 32) - 1;  // 0xffffffff;
+#endif  // SANITIZER_WORDSIZE
+}
+
 }  // namespace __asan
 
 // ---------------------- Interface ---------------- {{{1
@@ -299,6 +318,7 @@ void __asan_init() {
   if (asan_inited) return;
   CHECK(!asan_init_is_running && "ASan init calls itself!");
   asan_init_is_running = true;
+  InitializeHighMemEnd();
 
   // Make sure we are not statically linked.
   AsanDoesNotSupportStaticLinkage();

compiler-rt/lib/asan/tests/asan_noinst_test.cc

@@ -326,6 +326,7 @@ TEST(AddressSanitizer, ThreadedOneSizeMallocStressTest) {
 }
 
 TEST(AddressSanitizer, MemsetWildAddressTest) {
+  using __asan::kHighMemEnd;
   typedef void*(*memset_p)(void*, int, size_t);
   // Prevent inlining of memset().
   volatile memset_p libc_memset = (memset_p)memset;