On Tue, Jun 15, 2021 at 06:41:01AM +0000, Christophe Leroy wrote: > + unsafe_copy_to_user(__ucs_to, __ucs_from, \ > + sizeof(struct kernel_siginfo), label); \ > + unsafe_clear_user(__ucs_expansion, SI_EXPANSION_SIZE, label); \ > +} while (0) unsafe_clear_user does not exist at this point, and even your later patch only adds it for powerpc.