[compiler-rt] c0dc885 - [msan] Use non-transparent-huge-page at SetShadow

[Jianzhou Zhao via llvm-commits]

Author: Jianzhou Zhao
Date: 2021-02-27T00:28:57Z
New Revision: c0dc885d29af8f2bd2434047937c2ba65c7c7adb

URL: https://github.com/llvm/llvm-project/commit/c0dc885d29af8f2bd2434047937c2ba65c7c7adb
DIFF: https://github.com/llvm/llvm-project/commit/c0dc885d29af8f2bd2434047937c2ba65c7c7adb.diff

LOG: [msan] Use non-transparent-huge-page at SetShadow

This prevents from getting THP ranges more and more.

Did not see any issues in practice, just found this by code review.

Reviewed By: eugenis, vitalybuka

Differential Revision: https://reviews.llvm.org/D97593

Added: 
    

Modified: 
    compiler-rt/lib/msan/msan_poisoning.cpp

Removed: 
    


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diff  --git a/compiler-rt/lib/msan/msan_poisoning.cpp b/compiler-rt/lib/msan/msan_poisoning.cpp
index a92b0565cfa8..15892392f74a 100644
--- a/compiler-rt/lib/msan/msan_poisoning.cpp
+++ b/compiler-rt/lib/msan/msan_poisoning.cpp
@@ -213,7 +213,7 @@ void SetShadow(const void *ptr, uptr size, u8 value) {
       if (page_end != shadow_end) {
         REAL(memset)((void *)page_end, 0, shadow_end - page_end);
       }
-      if (!MmapFixedNoReserve(page_beg, page_end - page_beg))
+      if (!MmapFixedSuperNoReserve(page_beg, page_end - page_beg))
         Die();
     }
   }