sh: switch to generic sigaltstack

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

arch/sh/Kconfig

@@ -40,6 +40,7 @@ config SUPERH
 	select GENERIC_STRNLEN_USER
 	select HAVE_MOD_ARCH_SPECIFIC if DWARF_UNWINDER
 	select MODULES_USE_ELF_RELA
+	select GENERIC_SIGALTSTACK
 	help
 	  The SuperH is a RISC processor targeted for use in embedded systems
 	  and consumer electronics; it was also used in the Sega Dreamcast

arch/sh/include/asm/syscalls_32.h

@@ -12,9 +12,6 @@ struct pt_regs;
 asmlinkage int sys_sigsuspend(old_sigset_t mask);
 asmlinkage int sys_sigaction(int sig, const struct old_sigaction __user *act,
 			     struct old_sigaction __user *oact);
-asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
-			       unsigned long r6, unsigned long r7,
-			       struct pt_regs __regs);
 asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5,
 			     unsigned long r6, unsigned long r7,
 			     struct pt_regs __regs);

arch/sh/kernel/signal_32.c

@@ -89,17 +89,6 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
 	return ret;
 }
 
-asmlinkage int
-sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
-		unsigned long r6, unsigned long r7,
-		struct pt_regs __regs)
-{
-	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
-
-	return do_sigaltstack(uss, uoss, regs->regs[15]);
-}
-
-
 /*
  * Do a signal return; undo the signal stack.
  */
@@ -257,8 +246,7 @@ asmlinkage int sys_rt_sigreturn(unsigned long r4, unsigned long r5,
 	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
 		goto badframe;
 
-	if (do_sigaltstack(&frame->uc.uc_stack, NULL,
-			   regs->regs[15]) == -EFAULT)
+	if (restore_altstack(&frame->uc.uc_stack))
 		goto badframe;
 
 	return r0;
@@ -423,11 +411,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	/* Create the ucontext.  */
 	err |= __put_user(0, &frame->uc.uc_flags);
 	err |= __put_user(NULL, &frame->uc.uc_link);
-	err |= __put_user((void *)current->sas_ss_sp,
-			  &frame->uc.uc_stack.ss_sp);
-	err |= __put_user(sas_ss_flags(regs->regs[15]),
-			  &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->regs[15]);
 	err |= setup_sigcontext(&frame->uc.uc_mcontext,
 			        regs, set->sig[0]);
 	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));

arch/sh/kernel/signal_64.c

@@ -170,15 +170,6 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
 	return ret;
 }
 
-asmlinkage int
-sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
-	        unsigned long r4, unsigned long r5, unsigned long r6,
-	        unsigned long r7,
-	        struct pt_regs * regs)
-{
-	return do_sigaltstack(uss, uoss, REF_REG_SP);
-}
-
 /*
  * Do a signal return; undo the signal stack.
  */
@@ -364,9 +355,7 @@ asmlinkage int sys_rt_sigreturn(unsigned long r2, unsigned long r3,
 		goto badframe;
 	regs->pc -= 4;
 
-	/* It is more difficult to avoid calling this function than to
-	   call it and ignore errors.  */
-	if (do_sigaltstack(&frame->uc.uc_stack, NULL, REF_REG_SP) == -EFAULT)
+	if (restore_altstack(&frame->uc.uc_stack))
 		goto badframe;
 
 	return (int) ret;
@@ -560,11 +549,7 @@ static int setup_rt_frame(int sig, 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((void *)current->sas_ss_sp,
-			  &frame->uc.uc_stack.ss_sp);
-	err |= __put_user(sas_ss_flags(regs->regs[REG_SP]),
-			  &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->regs[REG_SP]);
 	err |= setup_sigcontext(&frame->uc.uc_mcontext,
 			        regs, set->sig[0]);
 	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));