arm64: switch to generic sigaltstack

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

1 files changed, 2 insertions, 15 deletions

diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index abd756315cb..890a591f75d 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -149,8 +149,7 @@ asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
 	if (restore_sigframe(regs, frame))
 		goto badframe;
 
-	if (do_sigaltstack(&frame->uc.uc_stack,
-			   NULL, regs->sp) == -EFAULT)
+	if (restore_altstack(&frame->uc.uc_stack))
 		goto badframe;
 
 	return regs->regs[0];
@@ -164,12 +163,6 @@ badframe:
 	return 0;
 }
 
-asmlinkage long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
-				unsigned long sp)
-{
-	return do_sigaltstack(uss, uoss, sp);
-}
-
 static int setup_sigframe(struct rt_sigframe __user *sf,
 			  struct pt_regs *regs, sigset_t *set)
 {
@@ -250,7 +243,6 @@ static int setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
 			  sigset_t *set, struct pt_regs *regs)
 {
 	struct rt_sigframe __user *frame;
-	stack_t stack;
 	int err = 0;
 
 	frame = get_sigframe(ka, regs);
@@ -260,12 +252,7 @@ static int setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
 	__put_user_error(0, &frame->uc.uc_flags, err);
 	__put_user_error(NULL, &frame->uc.uc_link, err);
 
-	memset(&stack, 0, sizeof(stack));
-	stack.ss_sp = (void __user *)current->sas_ss_sp;
-	stack.ss_flags = sas_ss_flags(regs->sp);
-	stack.ss_size = current->sas_ss_size;
-	err |= __copy_to_user(&frame->uc.uc_stack, &stack, sizeof(stack));
-
+	err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
 	err |= setup_sigframe(frame, regs, set);
 	if (err == 0) {
 		setup_return(regs, ka, frame, usig);