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Commit bfeb91a9 authored by Hiroshi Shimamoto's avatar Hiroshi Shimamoto Committed by Ingo Molnar
Browse files

x86: signal: cosmetic unification of __setup_sigframe() and __setup_rt_sigframe() 



Impact: cleanup

Add #ifdef directive to unify __setup_sigframe() and __setup_rt_sigframe().
Move them after {setup|restore}_sigcontext() declaration.

Signed-off-by: default avatarHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 2601657d

arch/x86/kernel/signal_32.c

+280 −189
Original line number Diff line number Diff line
@@ -48,28 +48,6 @@ 
# define FIX_EFLAGS	__FIX_EFLAGS

#endif



static const struct {

	u16 poplmovl;

	u32 val;

	u16 int80;

} __attribute__((packed)) retcode = {

	0xb858,		/* popl %eax; movl $..., %eax */

	__NR_sigreturn,

	0x80cd,		/* int $0x80 */

};



static const struct {

	u8  movl;

	u32 val;

	u16 int80;

	u8  pad;

} __attribute__((packed)) rt_retcode = {

	0xb8,		/* movl $..., %eax */

	__NR_rt_sigreturn,

	0x80cd,		/* int $0x80 */

	0

};



#define COPY(x)			{		\

	err |= __get_user(regs->x, &sc->x);	\

}
@@ -207,176 +185,30 @@ setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, 
}



/*

 * Atomically swap in the new signal mask, and wait for a signal.

 * Set up a signal frame.

 */

asmlinkage int

sys_sigsuspend(int history0, int history1, old_sigset_t mask)

{

	mask &= _BLOCKABLE;

	spin_lock_irq(&current->sighand->siglock);

	current->saved_sigmask = current->blocked;

	siginitset(&current->blocked, mask);

	recalc_sigpending();

	spin_unlock_irq(&current->sighand->siglock);



	current->state = TASK_INTERRUPTIBLE;

	schedule();

	set_restore_sigmask();



	return -ERESTARTNOHAND;

}



asmlinkage int

sys_sigaction(int sig, const struct old_sigaction __user *act,

	      struct old_sigaction __user *oact)

{

	struct k_sigaction new_ka, old_ka;

	int ret;



	if (act) {

		old_sigset_t mask;



		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||

		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||

		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))

			return -EFAULT;



		__get_user(new_ka.sa.sa_flags, &act->sa_flags);

		__get_user(mask, &act->sa_mask);

		siginitset(&new_ka.sa.sa_mask, mask);

	}



	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);



	if (!ret && oact) {

		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||

		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||

		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))

			return -EFAULT;



		__put_user(old_ka.sa.sa_flags, &oact->sa_flags);

		__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);

	}



	return ret;

}



#ifdef CONFIG_X86_32

asmlinkage int sys_sigaltstack(unsigned long bx)

{

	/*

	 * This is needed to make gcc realize it doesn't own the

	 * "struct pt_regs"

	 */

	struct pt_regs *regs = (struct pt_regs *)&bx;

	const stack_t __user *uss = (const stack_t __user *)bx;

	stack_t __user *uoss = (stack_t __user *)regs->cx;



	return do_sigaltstack(uss, uoss, regs->sp);

}

#else /* !CONFIG_X86_32 */

asmlinkage long

sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,

		struct pt_regs *regs)

{

	return do_sigaltstack(uss, uoss, regs->sp);

}

#endif /* CONFIG_X86_32 */



/*

 * Do a signal return; undo the signal stack.

 */

asmlinkage unsigned long sys_sigreturn(unsigned long __unused)

{

	struct sigframe __user *frame;

	struct pt_regs *regs;

	unsigned long ax;

	sigset_t set;



	regs = (struct pt_regs *) &__unused;

	frame = (struct sigframe __user *)(regs->sp - 8);



	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))

		goto badframe;

	if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1

		&& __copy_from_user(&set.sig[1], &frame->extramask,

				    sizeof(frame->extramask))))

		goto badframe;



	sigdelsetmask(&set, ~_BLOCKABLE);

	spin_lock_irq(&current->sighand->siglock);

	current->blocked = set;

	recalc_sigpending();

	spin_unlock_irq(&current->sighand->siglock);



	if (restore_sigcontext(regs, &frame->sc, &ax))

		goto badframe;

	return ax;



badframe:

	if (show_unhandled_signals && printk_ratelimit()) {

		printk("%s%s[%d] bad frame in sigreturn frame:"

			"%p ip:%lx sp:%lx oeax:%lx",

		    task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,

		    current->comm, task_pid_nr(current), frame, regs->ip,

		    regs->sp, regs->orig_ax);

		print_vma_addr(" in ", regs->ip);

		printk(KERN_CONT "\n");

	}



	force_sig(SIGSEGV, current);



	return 0;

}



static long do_rt_sigreturn(struct pt_regs *regs)

{

	struct rt_sigframe __user *frame;

	unsigned long ax;

	sigset_t set;



	frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))

		goto badframe;

	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))

		goto badframe;



	sigdelsetmask(&set, ~_BLOCKABLE);

	spin_lock_irq(&current->sighand->siglock);

	current->blocked = set;

	recalc_sigpending();

	spin_unlock_irq(&current->sighand->siglock);



	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))

		goto badframe;



	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)

		goto badframe;



	return ax;



badframe:

	signal_fault(regs, frame, "rt_sigreturn");

	return 0;

}



#ifdef CONFIG_X86_32

asmlinkage int sys_rt_sigreturn(unsigned long __unused)

{

	struct pt_regs *regs = (struct pt_regs *)&__unused;



	return do_rt_sigreturn(regs);

}

#else /* !CONFIG_X86_32 */

asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)

{

	return do_rt_sigreturn(regs);

}

#endif /* CONFIG_X86_32 */

static const struct {

	u16 poplmovl;

	u32 val;

	u16 int80;

} __attribute__((packed)) retcode = {

	0xb858,		/* popl %eax; movl $..., %eax */

	__NR_sigreturn,

	0x80cd,		/* int $0x80 */

};



/*

 * Set up a signal frame.

 */

static const struct {

	u8  movl;

	u32 val;

	u16 int80;

	u8  pad;

} __attribute__((packed)) rt_retcode = {

	0xb8,		/* movl $..., %eax */

	__NR_rt_sigreturn,

	0x80cd,		/* int $0x80 */

	0

};



/*

 * Determine which stack to use..
@@ -557,6 +389,265 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 


	return 0;

}

#else /* !CONFIG_X86_32 */

/*

 * Determine which stack to use..

 */

static void __user *

get_stack(struct k_sigaction *ka, unsigned long sp, unsigned long size)

{

	/* Default to using normal stack - redzone*/

	sp -= 128;



	/* This is the X/Open sanctioned signal stack switching.  */

	if (ka->sa.sa_flags & SA_ONSTACK) {

		if (sas_ss_flags(sp) == 0)

			sp = current->sas_ss_sp + current->sas_ss_size;

	}



	return (void __user *)round_down(sp - size, 64);

}



static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,

			    sigset_t *set, struct pt_regs *regs)

{

	struct rt_sigframe __user *frame;

	void __user *fp = NULL;

	int err = 0;

	struct task_struct *me = current;



	if (used_math()) {

		fp = get_stack(ka, regs->sp, sig_xstate_size);

		frame = (void __user *)round_down(

			(unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;



		if (save_i387_xstate(fp) < 0)

			return -EFAULT;

	} else

		frame = get_stack(ka, regs->sp, sizeof(struct rt_sigframe)) - 8;



	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))

		return -EFAULT;



	if (ka->sa.sa_flags & SA_SIGINFO) {

		if (copy_siginfo_to_user(&frame->info, info))

			return -EFAULT;

	}



	/* Create the ucontext.  */

	if (cpu_has_xsave)

		err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);

	else

		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(regs->sp),

			  &frame->uc.uc_stack.ss_flags);

	err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);

	err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);

	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));



	/* Set up to return from userspace.  If provided, use a stub

	   already in userspace.  */

	/* x86-64 should always use SA_RESTORER. */

	if (ka->sa.sa_flags & SA_RESTORER) {

		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);

	} else {

		/* could use a vstub here */

		return -EFAULT;

	}



	if (err)

		return -EFAULT;



	/* Set up registers for signal handler */

	regs->di = sig;

	/* In case the signal handler was declared without prototypes */

	regs->ax = 0;



	/* This also works for non SA_SIGINFO handlers because they expect the

	   next argument after the signal number on the stack. */

	regs->si = (unsigned long)&frame->info;

	regs->dx = (unsigned long)&frame->uc;

	regs->ip = (unsigned long) ka->sa.sa_handler;



	regs->sp = (unsigned long)frame;



	/* Set up the CS register to run signal handlers in 64-bit mode,

	   even if the handler happens to be interrupting 32-bit code. */

	regs->cs = __USER_CS;



	return 0;

}

#endif /* CONFIG_X86_32 */



/*

 * Atomically swap in the new signal mask, and wait for a signal.

 */

asmlinkage int

sys_sigsuspend(int history0, int history1, old_sigset_t mask)

{

	mask &= _BLOCKABLE;

	spin_lock_irq(&current->sighand->siglock);

	current->saved_sigmask = current->blocked;

	siginitset(&current->blocked, mask);

	recalc_sigpending();

	spin_unlock_irq(&current->sighand->siglock);



	current->state = TASK_INTERRUPTIBLE;

	schedule();

	set_restore_sigmask();



	return -ERESTARTNOHAND;

}



asmlinkage int

sys_sigaction(int sig, const struct old_sigaction __user *act,

	      struct old_sigaction __user *oact)

{

	struct k_sigaction new_ka, old_ka;

	int ret;



	if (act) {

		old_sigset_t mask;



		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||

		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||

		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))

			return -EFAULT;



		__get_user(new_ka.sa.sa_flags, &act->sa_flags);

		__get_user(mask, &act->sa_mask);

		siginitset(&new_ka.sa.sa_mask, mask);

	}



	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);



	if (!ret && oact) {

		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||

		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||

		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))

			return -EFAULT;



		__put_user(old_ka.sa.sa_flags, &oact->sa_flags);

		__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);

	}



	return ret;

}



#ifdef CONFIG_X86_32

asmlinkage int sys_sigaltstack(unsigned long bx)

{

	/*

	 * This is needed to make gcc realize it doesn't own the

	 * "struct pt_regs"

	 */

	struct pt_regs *regs = (struct pt_regs *)&bx;

	const stack_t __user *uss = (const stack_t __user *)bx;

	stack_t __user *uoss = (stack_t __user *)regs->cx;



	return do_sigaltstack(uss, uoss, regs->sp);

}

#else /* !CONFIG_X86_32 */

asmlinkage long

sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,

		struct pt_regs *regs)

{

	return do_sigaltstack(uss, uoss, regs->sp);

}

#endif /* CONFIG_X86_32 */



/*

 * Do a signal return; undo the signal stack.

 */

asmlinkage unsigned long sys_sigreturn(unsigned long __unused)

{

	struct sigframe __user *frame;

	struct pt_regs *regs;

	unsigned long ax;

	sigset_t set;



	regs = (struct pt_regs *) &__unused;

	frame = (struct sigframe __user *)(regs->sp - 8);



	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))

		goto badframe;

	if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1

		&& __copy_from_user(&set.sig[1], &frame->extramask,

				    sizeof(frame->extramask))))

		goto badframe;



	sigdelsetmask(&set, ~_BLOCKABLE);

	spin_lock_irq(&current->sighand->siglock);

	current->blocked = set;

	recalc_sigpending();

	spin_unlock_irq(&current->sighand->siglock);



	if (restore_sigcontext(regs, &frame->sc, &ax))

		goto badframe;

	return ax;



badframe:

	if (show_unhandled_signals && printk_ratelimit()) {

		printk("%s%s[%d] bad frame in sigreturn frame:"

			"%p ip:%lx sp:%lx oeax:%lx",

		    task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,

		    current->comm, task_pid_nr(current), frame, regs->ip,

		    regs->sp, regs->orig_ax);

		print_vma_addr(" in ", regs->ip);

		printk(KERN_CONT "\n");

	}



	force_sig(SIGSEGV, current);



	return 0;

}



static long do_rt_sigreturn(struct pt_regs *regs)

{

	struct rt_sigframe __user *frame;

	unsigned long ax;

	sigset_t set;



	frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))

		goto badframe;

	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))

		goto badframe;



	sigdelsetmask(&set, ~_BLOCKABLE);

	spin_lock_irq(&current->sighand->siglock);

	current->blocked = set;

	recalc_sigpending();

	spin_unlock_irq(&current->sighand->siglock);



	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))

		goto badframe;



	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)

		goto badframe;



	return ax;



badframe:

	signal_fault(regs, frame, "rt_sigreturn");

	return 0;

}



#ifdef CONFIG_X86_32

asmlinkage int sys_rt_sigreturn(unsigned long __unused)

{

	struct pt_regs *regs = (struct pt_regs *)&__unused;



	return do_rt_sigreturn(regs);

}

#else /* !CONFIG_X86_32 */

asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)

{

	return do_rt_sigreturn(regs);

}

#endif /* CONFIG_X86_32 */



/*

 * OK, we're invoking a handler:

arch/x86/kernel/signal_64.c

+256 −53
Original line number Diff line number Diff line
@@ -174,80 +174,212 @@ setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, 
	return err;

}



/*

 * Set up a signal frame.

 */

#ifdef CONFIG_X86_32

asmlinkage int sys_sigaltstack(unsigned long bx)

static const struct {

	u16 poplmovl;

	u32 val;

	u16 int80;

} __attribute__((packed)) retcode = {

	0xb858,		/* popl %eax; movl $..., %eax */

	__NR_sigreturn,

	0x80cd,		/* int $0x80 */

};



static const struct {

	u8  movl;

	u32 val;

	u16 int80;

	u8  pad;

} __attribute__((packed)) rt_retcode = {

	0xb8,		/* movl $..., %eax */

	__NR_rt_sigreturn,

	0x80cd,		/* int $0x80 */

	0

};



/*

 * Determine which stack to use..

 */

static inline void __user *

get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,

	     void **fpstate)

{

	unsigned long sp;



	/* Default to using normal stack */

	sp = regs->sp;



	/*

	 * This is needed to make gcc realize it doesn't own the

	 * "struct pt_regs"

	 * If we are on the alternate signal stack and would overflow it, don't.

	 * Return an always-bogus address instead so we will die with SIGSEGV.

	 */

	struct pt_regs *regs = (struct pt_regs *)&bx;

	const stack_t __user *uss = (const stack_t __user *)bx;

	stack_t __user *uoss = (stack_t __user *)regs->cx;

	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))

		return (void __user *) -1L;



	return do_sigaltstack(uss, uoss, regs->sp);

	/* This is the X/Open sanctioned signal stack switching.  */

	if (ka->sa.sa_flags & SA_ONSTACK) {

		if (sas_ss_flags(sp) == 0)

			sp = current->sas_ss_sp + current->sas_ss_size;

	} else {

		/* This is the legacy signal stack switching. */

		if ((regs->ss & 0xffff) != __USER_DS &&

			!(ka->sa.sa_flags & SA_RESTORER) &&

				ka->sa.sa_restorer)

			sp = (unsigned long) ka->sa.sa_restorer;

	}

#else /* !CONFIG_X86_32 */

asmlinkage long

sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,

		struct pt_regs *regs)

{

	return do_sigaltstack(uss, uoss, regs->sp);



	if (used_math()) {

		sp = sp - sig_xstate_size;

		*fpstate = (struct _fpstate *) sp;

		if (save_i387_xstate(*fpstate) < 0)

			return (void __user *)-1L;

	}

#endif /* CONFIG_X86_32 */



	sp -= frame_size;

	/*

 * Do a signal return; undo the signal stack.

	 * Align the stack pointer according to the i386 ABI,

	 * i.e. so that on function entry ((sp + 4) & 15) == 0.

	 */

static long do_rt_sigreturn(struct pt_regs *regs)

	sp = ((sp + 4) & -16ul) - 4;



	return (void __user *) sp;

}



static int

__setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,

	      struct pt_regs *regs)

{

	struct rt_sigframe __user *frame;

	unsigned long ax;

	sigset_t set;

	struct sigframe __user *frame;

	void __user *restorer;

	int err = 0;

	void __user *fpstate = NULL;



	frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))

		goto badframe;

	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))

		goto badframe;

	frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);



	sigdelsetmask(&set, ~_BLOCKABLE);

	spin_lock_irq(&current->sighand->siglock);

	current->blocked = set;

	recalc_sigpending();

	spin_unlock_irq(&current->sighand->siglock);

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))

		return -EFAULT;



	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))

		goto badframe;

	if (__put_user(sig, &frame->sig))

		return -EFAULT;



	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)

		goto badframe;

	if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))

		return -EFAULT;



	return ax;

	if (_NSIG_WORDS > 1) {

		if (__copy_to_user(&frame->extramask, &set->sig[1],

				   sizeof(frame->extramask)))

			return -EFAULT;

	}



	if (current->mm->context.vdso)

		restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);

	else

		restorer = &frame->retcode;

	if (ka->sa.sa_flags & SA_RESTORER)

		restorer = ka->sa.sa_restorer;



	/* Set up to return from userspace.  */

	err |= __put_user(restorer, &frame->pretcode);



	/*

	 * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80

	 *

	 * WE DO NOT USE IT ANY MORE! It's only left here for historical

	 * reasons and because gdb uses it as a signature to notice

	 * signal handler stack frames.

	 */

	err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode);



	if (err)

		return -EFAULT;



	/* Set up registers for signal handler */

	regs->sp = (unsigned long)frame;

	regs->ip = (unsigned long)ka->sa.sa_handler;

	regs->ax = (unsigned long)sig;

	regs->dx = 0;

	regs->cx = 0;



	regs->ds = __USER_DS;

	regs->es = __USER_DS;

	regs->ss = __USER_DS;

	regs->cs = __USER_CS;



badframe:

	signal_fault(regs, frame, "rt_sigreturn");

	return 0;

}



#ifdef CONFIG_X86_32

asmlinkage int sys_rt_sigreturn(unsigned long __unused)

static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,

			    sigset_t *set, struct pt_regs *regs)

{

	struct pt_regs *regs = (struct pt_regs *)&__unused;

	struct rt_sigframe __user *frame;

	void __user *restorer;

	int err = 0;

	void __user *fpstate = NULL;



	return do_rt_sigreturn(regs);

}

#else /* !CONFIG_X86_32 */

asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)

{

	return do_rt_sigreturn(regs);

}

#endif /* CONFIG_X86_32 */

	frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);



	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))

		return -EFAULT;



	err |= __put_user(sig, &frame->sig);

	err |= __put_user(&frame->info, &frame->pinfo);

	err |= __put_user(&frame->uc, &frame->puc);

	err |= copy_siginfo_to_user(&frame->info, info);

	if (err)

		return -EFAULT;



	/* Create the ucontext.  */

	if (cpu_has_xsave)

		err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);

	else

		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->sp),

			  &frame->uc.uc_stack.ss_flags);

	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);

	err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,

				regs, set->sig[0]);

	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));

	if (err)

		return -EFAULT;



	/* Set up to return from userspace.  */

	restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);

	if (ka->sa.sa_flags & SA_RESTORER)

		restorer = ka->sa.sa_restorer;

	err |= __put_user(restorer, &frame->pretcode);



	/*

 * Set up a signal frame.

	 * This is movl $__NR_rt_sigreturn, %ax ; int $0x80

	 *

	 * WE DO NOT USE IT ANY MORE! It's only left here for historical

	 * reasons and because gdb uses it as a signature to notice

	 * signal handler stack frames.

	 */

	err |= __put_user(*((u64 *)&rt_retcode), (u64 *)frame->retcode);



	if (err)

		return -EFAULT;



	/* Set up registers for signal handler */

	regs->sp = (unsigned long)frame;

	regs->ip = (unsigned long)ka->sa.sa_handler;

	regs->ax = (unsigned long)sig;

	regs->dx = (unsigned long)&frame->info;

	regs->cx = (unsigned long)&frame->uc;



	regs->ds = __USER_DS;

	regs->es = __USER_DS;

	regs->ss = __USER_DS;

	regs->cs = __USER_CS;



	return 0;

}

#else /* !CONFIG_X86_32 */

/*

 * Determine which stack to use..

 */
@@ -337,6 +469,77 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 


	return 0;

}

#endif /* CONFIG_X86_32 */



#ifdef CONFIG_X86_32

asmlinkage int sys_sigaltstack(unsigned long bx)

{

	/*

	 * This is needed to make gcc realize it doesn't own the

	 * "struct pt_regs"

	 */

	struct pt_regs *regs = (struct pt_regs *)&bx;

	const stack_t __user *uss = (const stack_t __user *)bx;

	stack_t __user *uoss = (stack_t __user *)regs->cx;



	return do_sigaltstack(uss, uoss, regs->sp);

}

#else /* !CONFIG_X86_32 */

asmlinkage long

sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,

		struct pt_regs *regs)

{

	return do_sigaltstack(uss, uoss, regs->sp);

}

#endif /* CONFIG_X86_32 */



/*

 * Do a signal return; undo the signal stack.

 */

static long do_rt_sigreturn(struct pt_regs *regs)

{

	struct rt_sigframe __user *frame;

	unsigned long ax;

	sigset_t set;



	frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))

		goto badframe;

	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))

		goto badframe;



	sigdelsetmask(&set, ~_BLOCKABLE);

	spin_lock_irq(&current->sighand->siglock);

	current->blocked = set;

	recalc_sigpending();

	spin_unlock_irq(&current->sighand->siglock);



	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))

		goto badframe;



	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)

		goto badframe;



	return ax;



badframe:

	signal_fault(regs, frame, "rt_sigreturn");

	return 0;

}



#ifdef CONFIG_X86_32

asmlinkage int sys_rt_sigreturn(unsigned long __unused)

{

	struct pt_regs *regs = (struct pt_regs *)&__unused;



	return do_rt_sigreturn(regs);

}

#else /* !CONFIG_X86_32 */

asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)

{

	return do_rt_sigreturn(regs);

}

#endif /* CONFIG_X86_32 */



/*

 * OK, we're invoking a handler