hurd: break relocation loop between libc.so and lib{mach,hurd}user.so

See
https://sourceware.org/pipermail/libc-alpha/2020-November/119575.html

lib{mach,hurd}user.so gets relocated before libc.so, but its references
to strpcpy and memcpy would need an ifunc decision, which e.g. on
x86 relies on cpu_features, but libc.so's _rtld_global_ro is not
relocated yet.

We can however just make lib{mach,hurd}user.so only call non-ifunc
functions, which can be relocated before libc.so is relocated.

1 files changed, 4 insertions, 0 deletions

diff --git a/mach/Versions b/mach/Versions
index eef52c8..b525cfd 100644
--- a/mach/Versions
+++ b/mach/Versions
@@ -68,4 +68,8 @@ libc {
     __spin_lock; __spin_lock_init; __spin_lock_solid; __spin_try_lock;
     __spin_unlock;
   }
+  GLIBC_PRIVATE {
+    # functions used by RPC stubs
+    __mig_memcpy;
+  }
 }