[compiler-rt] Fixed Android 8.1 getauxval(AT_PAGESZ) crashes if called from .preinit_array. (#113427)

Author: funsafe-ptr

compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp

@@ -82,6 +82,11 @@
 #    include <sys/personality.h>
 #  endif
 
+# if SANITIZER_ANDROID && __ANDROID_API__ < 35
+// The weak strerrorname_np definition allows to check for the API level at runtime.
+extern "C" SANITIZER_WEAK_ATTRIBUTE const char* strerrorname_np(int);
+# endif
+
 #  if SANITIZER_LINUX && defined(__loongarch__)
 #    include <sys/sysmacros.h>
 #  endif
@@ -1214,6 +1219,12 @@ uptr GetPageSize() {
   CHECK_EQ(rv, 0);
   return (uptr)pz;
 #    elif SANITIZER_USE_GETAUXVAL
+
+#      if SANITIZER_ANDROID && __ANDROID_API__ < 35
+  if (!strerrorname_np)
+    return 4096;
+#      endif
+
   return getauxval(AT_PAGESZ);
 #    else
   return sysconf(_SC_PAGESIZE);  // EXEC_PAGESIZE may not be trustworthy.