Invalidate icache in copy_to_executable_mem()

This should be a no-op on x86 (unified icache and dcache), but is required on
ARM because the icache and dcache are separate.

The Pixel C bots are crashing at head, and so is my local Pixel C, but not
after this CL.  Interestingly, my Pixel not-C (phone) has always been fine.
I wonder if it has a unifed cache?

CQ_INCLUDE_TRYBOTS=skia.primary:Test-Android-Clang-PixelC-CPU-TegraX1-arm64-Release-Android

Change-Id: I8f9d53729613c51aabfeb49495aac38ce2801a84
Reviewed-on: https://skia-review.googlesource.com/6847
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/splicer/SkSplicer.cpp b/src/splicer/SkSplicer.cpp
index f1a8c8930c..e68adabd3f 100644
--- a/src/splicer/SkSplicer.cpp
+++ b/src/splicer/SkSplicer.cpp
@@ -113,7 +113,9 @@ namespace {
         if (src && len) {
             // TODO: w^x
             auto fn = mmap(nullptr, len, PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, -1, 0);
-            return memcpy(fn, src, len);
+            memcpy(fn, src, len);
+            __builtin___clear_cache((char*)fn, (char*)fn + len);
+            return fn;
         }
         return nullptr;
     }