new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those

note that they are relying on access_ok() already checked by caller.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 1 insertions, 4 deletions

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index a866411a2fcc..a1daf4a65009 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -467,10 +467,7 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                 else
                         put_user_ex(0, &frame->uc.uc_flags);
                 put_user_ex(0, &frame->uc.uc_link);
-                put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
-                put_user_ex(sas_ss_flags(regs->sp),
-                            &frame->uc.uc_stack.ss_flags);
-                put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+                err |= __compat_save_altstack(&frame->uc.uc_stack, regs->sp);
 
                 if (ka->sa.sa_flags & SA_RESTORER)
                         restorer = ka->sa.sa_restorer;