Merge "Avoid crashing on bad architecture value." into main
diff --git a/init/security.cpp b/init/security.cpp
index 0c73fae..3e15447 100644
--- a/init/security.cpp
+++ b/init/security.cpp
@@ -20,6 +20,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <linux/perf_event.h>
+#include <math.h>
 #include <selinux/selinux.h>
 #include <sys/ioctl.h>
 #include <sys/syscall.h>
@@ -121,8 +122,12 @@
     }
 #elif defined(__x86_64__)
     // x86_64 supports 28 - 32 rnd bits, but Android wants to ensure that the
-    // theoretical maximum of 32 bits is always supported and used.
-    if (SetMmapRndBitsMin(32, 32, false) && (!Has32BitAbi() || SetMmapRndBitsMin(16, 16, true))) {
+    // theoretical maximum of 32 bits is always supported and used; except in
+    // the case of the x86 page size emulator which supports a maximum
+    // of 30 bits for 16k page size, or 28 bits for 64k page size.
+    int max_bits = 32 - (static_cast<int>(log2(getpagesize())) - 12);
+    if (SetMmapRndBitsMin(max_bits, max_bits, false) &&
+        (!Has32BitAbi() || SetMmapRndBitsMin(16, 16, true))) {
         return {};
     }
 #elif defined(__arm__) || defined(__i386__)