[PATCH] D113443: [FreeBSD] avoid marking __stack_chk_guard symbol as dso_local on PPC64

[Alfredo Dal'Ava Júnior via Phabricator via llvm-commits]

adalava created this revision.
adalava added reviewers: nemanjai, MaskRay, dim, PowerPC, sfertile, emaste.
Herald added subscribers: shchenz, hiraditya, krytarowski, arichardson.
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Amends 1cb9f37a17ab <https://reviews.llvm.org/rG1cb9f37a17ab528e53d38c790c1bc44a087d2a50> restricting the logic to PPC64 as it introduces regression of FreeBSD/amd64 binaries compiled in freestanding mode (as kernel and modules) as discussed in https://reviews.llvm.org/D109090.

Bug report https://bugs.llvm.org/show_bug.cgi?id=51590


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D113443

Files:
  llvm/lib/CodeGen/TargetLoweringBase.cpp


Index: llvm/lib/CodeGen/TargetLoweringBase.cpp
===================================================================
--- llvm/lib/CodeGen/TargetLoweringBase.cpp
+++ llvm/lib/CodeGen/TargetLoweringBase.cpp
@@ -1988,10 +1988,16 @@
                                   GlobalVariable::ExternalLinkage, nullptr,
                                   "__stack_chk_guard");
 
-    // FreeBSD has "__stack_chk_guard" defined externally on libc.so
+    // XXX -- needs more investigation
+    // FreeBSD userland has "__stack_chk_guard" defined externally on libc.so,
+    // so not dso_local. Kernel modules are compiled in freestanding mode, it
+    // can be considered dso_local. For unknown reasons set dso_local here
+    // breaks PPC64 userland binaries (see bug #51590).
+    // However, FreeBSD amd64 kernel and modules are broken if dso_local
+    // is not set here, while PCC64 kernel and modules are fine without it.
     if (TM.getRelocationModel() == Reloc::Static &&
         !TM.getTargetTriple().isWindowsGNUEnvironment() &&
-        !TM.getTargetTriple().isOSFreeBSD())
+        !(TM.getTargetTriple().isPPC64() && TM.getTargetTriple().isOSFreeBSD()))
       GV->setDSOLocal(true);
   }
 }


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