powerpc: switch to generic sigaltstack

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

1 files changed, 3 insertions, 8 deletions

diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 1ca045d44324..807b5b1535e9 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -368,10 +368,8 @@ int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
         if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
                 goto badframe;
 
-        /* do_sigaltstack expects a __user pointer and won't modify
-         * what's in there anyway
-         */
-        do_sigaltstack(&uc->uc_stack, NULL, regs->gpr[1]);
+        if (restore_altstack(&uc->uc_stack))
+                goto badframe;
 
         set_thread_flag(TIF_RESTOREALL);
         return 0;
@@ -416,10 +414,7 @@ int handle_rt_signal64(int signr, struct k_sigaction *ka, siginfo_t *info,
         /* Create the ucontext.  */
         err |= __put_user(0, &frame->uc.uc_flags);
         err |= __put_user(0, &frame->uc.uc_link);
-        err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
-        err |= __put_user(sas_ss_flags(regs->gpr[1]),
-                          &frame->uc.uc_stack.ss_flags);
-        err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+        err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]);
         err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr, NULL,
                                 (unsigned long)ka->sa.sa_handler, 1);
         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));