The GlobalISel IRTranslator pass assumes that it is safe to use the

LOAD_STACK_GUARD pseudo without consulting the value of useLoadStackGuardNode(),
and then tries to add the return from getSDagStackGuard() as a parameter without
consulting the return from getIRStackGuard() to see if it should do that. This
means that the GlobalISel IRTranslator's implementation for
Intrinsic::stackprotector is broken for platforms that implement
getIRStackGuard() like we do, and this causes a segfault later when the
incomplete LOAD_STACK_GUARD pseudo is lowered in the back end.

Since GlobalISel is disabled on aarch64 most of the time anyway, add a bit that
disables it for OpenBSD/aarch64 all the time.

Fixes a crash when building on aarch64 without retguard, with a stack protector
and without optimizations, which manifests when building cross-tools.

ok patrick@ deraadt@

1 files changed, 2 insertions, 1 deletions

diff --git a/gnu/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp b/gnu/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
index 219c33ef73c..994130c66af 100644
--- a/gnu/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
+++ b/gnu/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
@@ -276,7 +276,8 @@ AArch64TargetMachine::AArch64TargetMachine(const Target &T, const Triple &TT,
   }
 
   // Enable GlobalISel at or below EnableGlobalISelAt0.
-  if (getOptLevel() <= EnableGlobalISelAtO) {
+  if (getOptLevel() <= EnableGlobalISelAtO &&
+      !getTargetTriple().isOSOpenBSD()) {
     setGlobalISel(true);
     setGlobalISelAbort(GlobalISelAbortMode::Disable);
   }