Commit c40702c4 authored by Al Viro's avatar Al Viro
Browse files

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: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 90268439

arch/x86/ia32/ia32_signal.c

+1 −4
Original line number Diff line number Diff line
@@ -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;

arch/x86/kernel/signal.c

+4 −14
Original line number Diff line number Diff line
@@ -363,10 +363,7 @@ static int __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 |= __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 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 
	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 @@ static int __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(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 @@ static int x32_setup_rt_frame(int sig, struct k_sigaction *ka, 
		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 @@ long sys_rt_sigreturn(struct pt_regs *regs) 
	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

+2 −7
Original line number Diff line number Diff line
@@ -342,9 +342,7 @@ static int copy_ucontext_to_user(struct ucontext __user *uc, 
{

	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 @@ int setup_signal_stack_si(unsigned long stack_top, int sig, 
	/* 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);

include/linux/compat.h

+1 −0
Original line number Diff line number Diff line
@@ -647,6 +647,7 @@ asmlinkage long compat_sys_sigaltstack(const compat_stack_t __user *uss_ptr, 
				       compat_stack_t __user *uoss_ptr);



int compat_restore_altstack(const compat_stack_t __user *uss);

int __compat_save_altstack(compat_stack_t __user *, unsigned long);

#endif



#else

include/linux/signal.h

+1 −0
Original line number Diff line number Diff line
@@ -386,5 +386,6 @@ int unhandled_signal(struct task_struct *tsk, int sig); 
void signals_init(void);



int restore_altstack(const stack_t __user *);

int __save_altstack(stack_t __user *, unsigned long);



#endif /* _LINUX_SIGNAL_H */