[compiler-rt] r330598 - [scudo] Read ARM feature bits using Fuchsia APIs.

[Kostya Kortchinsky via llvm-commits]

Author: cryptoad
Date: Mon Apr 23 07:53:13 2018
New Revision: 330598

URL: http://llvm.org/viewvc/llvm-project?rev=330598&view=rev
Log:
[scudo] Read ARM feature bits using Fuchsia APIs.

Summary:
    Fuchsia uses zx_system_get_features in lieu of getauxval.
    
    Use this call when checking for CRC32 support.

Reviewers: cryptoad

Reviewed By: cryptoad

Subscribers: delcypher, llvm-commits, #sanitizers, kristof.beyls, chrib

Differential Revision: https://reviews.llvm.org/D45896

Modified:
    compiler-rt/trunk/lib/scudo/scudo_utils.cpp

Modified: compiler-rt/trunk/lib/scudo/scudo_utils.cpp
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/scudo/scudo_utils.cpp?rev=330598&r1=330597&r2=330598&view=diff
==============================================================================
--- compiler-rt/trunk/lib/scudo/scudo_utils.cpp (original)
+++ compiler-rt/trunk/lib/scudo/scudo_utils.cpp Mon Apr 23 07:53:13 2018
@@ -17,7 +17,10 @@
 # include <cpuid.h>
 #elif defined(__arm__) || defined(__aarch64__)
 # include "sanitizer_common/sanitizer_getauxval.h"
-# if SANITIZER_POSIX
+# if SANITIZER_FUCHSIA
+#  include <zircon/syscalls.h>
+#  include <zircon/features.h>
+# elif SANITIZER_POSIX
 #  include "sanitizer_common/sanitizer_posix.h"
 #  include <fcntl.h>
 # endif
@@ -110,9 +113,17 @@ INLINE bool areBionicGlobalsInitialized(
 }
 
 bool hasHardwareCRC32() {
+#if SANITIZER_FUCHSIA
+  u32 HWCap;
+  zx_status_t Status = zx_system_get_features(ZX_FEATURE_KIND_CPU, &HWCap);
+  if (Status != ZX_OK || (HWCap & ZX_ARM64_FEATURE_ISA_CRC32) == 0)
+    return false;
+  return true;
+#else
   if (&getauxval && areBionicGlobalsInitialized())
     return !!(getauxval(AT_HWCAP) & HWCAP_CRC32);
   return hasHardwareCRC32ARMPosix();
+#endif  // SANITIZER_FUCHSIA
 }
 #else
 bool hasHardwareCRC32() { return false; }