commit c40702c49faef05ae324f121d8b3e215244ee152
author Al Viro <viro@zeniv.linux.org.uk> Tue Nov 20 14:24:26 2012 -0500
committer Al Viro <viro@zeniv.linux.org.uk> Wed Dec 19 18:07:41 2012 -0500
tree b0b2a51b07e944497da5cb48fb461963a3762cad
parent 9026843952adac5b123c7b8dc961e5c15828d9e1

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>

arch/x86/ia32/ia32_signal.c

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index a866411..a1daf4a 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -467,10 +467,7 @@
 		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;

arch/x86/kernel/signal.c

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index b17ed37..a6c8a34 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -363,10 +363,7 @@
 		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 |= __save_altstack(&frame->uc.uc_stack, regs->sp);
 
 		/* Set up to return from userspace.  */
 		restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
@@ -413,7 +410,6 @@
 	struct rt_sigframe __user *frame;
 	void __user *fp = NULL;
 	int err = 0;
-	struct task_struct *me = current;
 
 	frame = get_sigframe(ka, regs, sizeof(struct rt_sigframe), &fp);
 
@@ -432,10 +428,7 @@
 		else
 			put_user_ex(0, &frame->uc.uc_flags);
 		put_user_ex(0, &frame->uc.uc_link);
-		put_user_ex(me->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(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
+		err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
 
 		/* Set up to return from userspace.  If provided, use a stub
 		   already in userspace.  */
@@ -502,10 +495,7 @@
 		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);
 		put_user_ex(0, &frame->uc.uc__pad0);
 
 		if (ka->sa.sa_flags & SA_RESTORER) {
@@ -651,7 +641,7 @@
 	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
 		goto badframe;
 
-	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
+	if (restore_altstack(&frame->uc.uc_stack))
 		goto badframe;
 
 	return ax;

arch/x86/um/signal.c

diff --git a/arch/x86/um/signal.c b/arch/x86/um/signal.c
index bdaa08c..71cef48 100644
--- a/arch/x86/um/signal.c
+++ b/arch/x86/um/signal.c
@@ -342,9 +342,7 @@
 {
 	int err = 0;
 
-	err |= put_user(current->sas_ss_sp, &uc->uc_stack.ss_sp);
-	err |= put_user(sas_ss_flags(sp), &uc->uc_stack.ss_flags);
-	err |= put_user(current->sas_ss_size, &uc->uc_stack.ss_size);
+	err |= __save_altstack(&uc->uc_stack, sp);
 	err |= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs, 0);
 	err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
 	return err;
@@ -529,10 +527,7 @@
 	/* Create the ucontext.  */
 	err |= __put_user(0, &frame->uc.uc_flags);
 	err |= __put_user(0, &frame->uc.uc_link);
-	err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
-	err |= __put_user(sas_ss_flags(PT_REGS_SP(regs)),
-			  &frame->uc.uc_stack.ss_flags);
-	err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
+	err |= __save_altstack(&frame->uc.uc_stack, PT_REGS_SP(regs));
 	err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
 			       set->sig[0]);
 	err |= __put_user(&frame->fpstate, &frame->uc.uc_mcontext.fpstate);