[compiler-rt] [libcxxabi] [libunwind] [runtimes][PAC] Harden unwinding when possible (#138571) (PR #143230)

[Anatoly Trosinenko via llvm-commits]

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@@ -767,6 +767,11 @@ LnoR2Fix:
 //
   .p2align 2
 DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
+
+#if __has_feature(ptrauth_calls)
+  pacibsp
+#endif
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atrosinenko wrote:

Possibly `ptrauth_returns` intended?

https://github.com/llvm/llvm-project/pull/143230