[compiler-rt] 7d35226 - [msan] Change personality CHECK to Printf() + Die() (#160626)

[via llvm-commits]

Author: Thurston Dang
Date: 2025-09-25T08:23:47-07:00
New Revision: 7d35226173fad2f5d6a2b082583843ebcb8cea53

URL: https://github.com/llvm/llvm-project/commit/7d35226173fad2f5d6a2b082583843ebcb8cea53
DIFF: https://github.com/llvm/llvm-project/commit/7d35226173fad2f5d6a2b082583843ebcb8cea53.diff

LOG: [msan] Change personality CHECK to Printf() + Die() (#160626)

This ports https://github.com/llvm/llvm-project/pull/142821 from TSan.

Although MSan doesn't segfault the way TSan did, the failure message was
nonetheless cryptic. The improved error message will prepare MSan for
the upcoming AppArmorpocalypse.

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/msan/msan_linux.cpp b/compiler-rt/lib/msan/msan_linux.cpp
index 7140de7e9c543..f08a7c98a4847 100644
--- a/compiler-rt/lib/msan/msan_linux.cpp
+++ b/compiler-rt/lib/msan/msan_linux.cpp
@@ -190,7 +190,15 @@ bool InitShadowWithReExec(bool init_origins) {
               "possibly due to high-entropy ASLR.\n"
               "Re-execing with fixed virtual address space.\n"
               "N.B. reducing ASLR entropy is preferable.\n");
-      CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
+
+      if (personality(old_personality | ADDR_NO_RANDOMIZE) == -1) {
+        Printf(
+            "FATAL: MemorySanitizer: unable to disable ASLR (perhaps "
+            "sandboxing is enabled?).\n");
+        Printf("FATAL: Please rerun without sandboxing and/or ASLR.\n");
+        Die();
+      }
+
       ReExec();
     }
 #  endif