[PATCH] D13818: [compiler-rt] [msan] Unify aarch64 mapping

[Evgeniy Stepanov via llvm-commits]

eugenis added a comment.

To clarify, 12-13% is based on the whole address space, as in 1<<39, and not just user-addressable part?
Because on x86_64, for example, userspace is only allowed to map up to 0x800000000000, and MSan leaves 25% of that to the application, which is close to the theoretical limit of 33%.


================
Comment at: lib/msan/msan.h:75
@@ +74,3 @@
+    {0x04600000000ULL, 0x05500000000ULL, MappingDesc::INVALID, "invalid"},
+    {0x05500000000ULL, 0x05600000000ULL, MappingDesc::APP, "app-1"},
+    {0x05600000000ULL, 0x07000000000ULL, MappingDesc::INVALID, "invalid"},
----------------
Why just 55 to 56? The whole 50 to 60 seems ok.

In general, I don't see a reason why the third hexadecimal digit can be anything but 0, please reconsider another case of this below.


http://reviews.llvm.org/D13818