[PATCH] D70762: scudo: Add initial memory tagging support.

Thu Jan 16 07:42:18 PST 2020

cryptoad added a comment.

I think this looks good. I think this might not be Fuchsia compatible and could probably use some `#if SCUDO_LINUX` or ANDROID or top of the `__aarch64__` checks.
Fuchsia will want memory tagging support at some point, I 'll check the patch on the platform once the inconsistencies I saw are addressed.

================
Comment at: compiler-rt/lib/scudo/standalone/combined.h:199

+  void *untagPointerMaybe(void *Ptr) {
+    if (Primary.SupportsMemoryTagging)
----------------
I am assuming the compiler will inline this most of the time, but could we put that `inline` or `FORCE_INLINE` to double down?

================
Comment at: compiler-rt/lib/scudo/standalone/memtag.h:14
+
+#include <sys/auxv.h>
+#include <sys/prctl.h>
----------------
If I followed properly `memtag.h` is included on all platforms, but I am not sure `sys/*.h` is available everywhere (Fuchsia doesn't have one).
So this probably requires some `#if SCUDO_LINUX` or something to that extent?

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D70762/new/

https://reviews.llvm.org/D70762