arch/x86/ia32/ia32_signal.c - kernel/windcharger - Git at Google

 /*
  *  linux/arch/x86_64/ia32/ia32_signal.c
  *
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *
  *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
  *  2000-06-20  Pentium III FXSR, SSE support by Gareth Hughes
  *  2000-12-*   x86-64 compatibility mode signal handling by Andi Kleen
  */

 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
 #include <linux/kernel.h>
 #include <linux/signal.h>
 #include <linux/errno.h>
 #include <linux/wait.h>
 #include <linux/ptrace.h>
 #include <linux/unistd.h>
 #include <linux/stddef.h>
 #include <linux/personality.h>
 #include <linux/compat.h>
 #include <linux/binfmts.h>
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
 #include <asm/i387.h>
 #include <asm/ptrace.h>
 #include <asm/ia32_unistd.h>
 #include <asm/user32.h>
 #include <asm/sigcontext32.h>
 #include <asm/proto.h>
 #include <asm/vdso.h>
 #include <asm/sigframe.h>
 #include <asm/sys_ia32.h>

 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))

 #define FIX_EFLAGS	(X86_EFLAGS_AC | X86_EFLAGS_OF | \
 			 X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \
 			 X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \
 			 X86_EFLAGS_CF)

 void signal_fault(struct pt_regs *regs, void __user *frame, char *where);

 int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
 {
 	int err = 0;

 	if (!access_ok(VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
 		return -EFAULT;

 	put_user_try {
 		/* If you change siginfo_t structure, please make sure that
 		   this code is fixed accordingly.
 		   It should never copy any pad contained in the structure
 		   to avoid security leaks, but must copy the generic
 		   3 ints plus the relevant union member.  */
 		put_user_ex(from->si_signo, &to->si_signo);
 		put_user_ex(from->si_errno, &to->si_errno);
 		put_user_ex((short)from->si_code, &to->si_code);

 		if (from->si_code < 0) {
 			put_user_ex(from->si_pid, &to->si_pid);
 			put_user_ex(from->si_uid, &to->si_uid);
 			put_user_ex(ptr_to_compat(from->si_ptr), &to->si_ptr);
 		} else {
 			/*
 			 * First 32bits of unions are always present:
 			 * si_pid === si_band === si_tid === si_addr(LS half)
 			 */
 			put_user_ex(from->_sifields._pad[0],
 					  &to->_sifields._pad[0]);
 			switch (from->si_code >> 16) {
 			case __SI_FAULT >> 16:
 				break;
 			case __SI_CHLD >> 16:
 				put_user_ex(from->si_utime, &to->si_utime);
 				put_user_ex(from->si_stime, &to->si_stime);
 				put_user_ex(from->si_status, &to->si_status);
 				/* FALL THROUGH */
 			default:
 			case __SI_KILL >> 16:
 				put_user_ex(from->si_uid, &to->si_uid);
 				break;
 			case __SI_POLL >> 16:
 				put_user_ex(from->si_fd, &to->si_fd);
 				break;
 			case __SI_TIMER >> 16:
 				put_user_ex(from->si_overrun, &to->si_overrun);
 				put_user_ex(ptr_to_compat(from->si_ptr),
 					    &to->si_ptr);
 				break;
 				 /* This is not generated by the kernel as of now.  */
 			case __SI_RT >> 16:
 			case __SI_MESGQ >> 16:
 				put_user_ex(from->si_uid, &to->si_uid);
 				put_user_ex(from->si_int, &to->si_int);
 				break;
 			}
 		}
 	} put_user_catch(err);

 	return err;
 }

 int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
 {
 	int err = 0;
 	u32 ptr32;

 	if (!access_ok(VERIFY_READ, from, sizeof(compat_siginfo_t)))
 		return -EFAULT;

 	get_user_try {
 		get_user_ex(to->si_signo, &from->si_signo);
 		get_user_ex(to->si_errno, &from->si_errno);
 		get_user_ex(to->si_code, &from->si_code);

 		get_user_ex(to->si_pid, &from->si_pid);
 		get_user_ex(to->si_uid, &from->si_uid);
 		get_user_ex(ptr32, &from->si_ptr);
 		to->si_ptr = compat_ptr(ptr32);
 	} get_user_catch(err);

 	return err;
 }

 asmlinkage long sys32_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 long sys32_sigaltstack(const stack_ia32_t __user *uss_ptr,
 				  stack_ia32_t __user *uoss_ptr,
 				  struct pt_regs *regs)
 {
 	stack_t uss, uoss;
 	int ret, err = 0;
 	mm_segment_t seg;

 	if (uss_ptr) {
 		u32 ptr;

 		memset(&uss, 0, sizeof(stack_t));
 		if (!access_ok(VERIFY_READ, uss_ptr, sizeof(stack_ia32_t)))
 			return -EFAULT;

 		get_user_try {
 			get_user_ex(ptr, &uss_ptr->ss_sp);
 			get_user_ex(uss.ss_flags, &uss_ptr->ss_flags);
 			get_user_ex(uss.ss_size, &uss_ptr->ss_size);
 		} get_user_catch(err);

 		if (err)
 			return -EFAULT;
 		uss.ss_sp = compat_ptr(ptr);
 	}
 	seg = get_fs();
 	set_fs(KERNEL_DS);
 	ret = do_sigaltstack(uss_ptr ? &uss : NULL, &uoss, regs->sp);
 	set_fs(seg);
 	if (ret >= 0 && uoss_ptr)  {
 		if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(stack_ia32_t)))
 			return -EFAULT;

 		put_user_try {
 			put_user_ex(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp);
 			put_user_ex(uoss.ss_flags, &uoss_ptr->ss_flags);
 			put_user_ex(uoss.ss_size, &uoss_ptr->ss_size);
 		} put_user_catch(err);

 		if (err)
 			ret = -EFAULT;
 	}
 	return ret;
 }

 /*
  * Do a signal return; undo the signal stack.
  */
 #define loadsegment_gs(v)	load_gs_index(v)
 #define loadsegment_fs(v)	loadsegment(fs, v)
 #define loadsegment_ds(v)	loadsegment(ds, v)
 #define loadsegment_es(v)	loadsegment(es, v)

 #define get_user_seg(seg)	({ unsigned int v; savesegment(seg, v); v; })
 #define set_user_seg(seg, v)	loadsegment_##seg(v)

 #define COPY(x)			{		\
 	get_user_ex(regs->x, &sc->x);		\
 }

 #define GET_SEG(seg)		({			\
 	unsigned short tmp;				\
 	get_user_ex(tmp, &sc->seg);			\
 	tmp;						\
 })

 #define COPY_SEG_CPL3(seg)	do {			\
 	regs->seg = GET_SEG(seg) | 3;			\
 } while (0)

 #define RELOAD_SEG(seg)		{		\
 	unsigned int pre = GET_SEG(seg);	\
 	unsigned int cur = get_user_seg(seg);	\
 	pre |= 3;				\
 	if (pre != cur)				\
 		set_user_seg(seg, pre);		\
 }

 static int ia32_restore_sigcontext(struct pt_regs *regs,
 				   struct sigcontext_ia32 __user *sc,
 				   unsigned int *pax)
 {
 	unsigned int tmpflags, err = 0;
 	void __user *buf;
 	u32 tmp;

 	/* Always make any pending restarted system calls return -EINTR */
 	current_thread_info()->restart_block.fn = do_no_restart_syscall;

 	get_user_try {
 		/*
 		 * Reload fs and gs if they have changed in the signal
 		 * handler.  This does not handle long fs/gs base changes in
 		 * the handler, but does not clobber them at least in the
 		 * normal case.
 		 */
 		RELOAD_SEG(gs);
 		RELOAD_SEG(fs);
 		RELOAD_SEG(ds);
 		RELOAD_SEG(es);

 		COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
 		COPY(dx); COPY(cx); COPY(ip);
 		/* Don't touch extended registers */

 		COPY_SEG_CPL3(cs);
 		COPY_SEG_CPL3(ss);

 		get_user_ex(tmpflags, &sc->flags);
 		regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
 		/* disable syscall checks */
 		regs->orig_ax = -1;

 		get_user_ex(tmp, &sc->fpstate);
 		buf = compat_ptr(tmp);
 		err |= restore_i387_xstate_ia32(buf);

 		get_user_ex(*pax, &sc->ax);
 	} get_user_catch(err);

 	return err;
 }

 asmlinkage long sys32_sigreturn(struct pt_regs *regs)
 {
 	struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
 	sigset_t set;
 	unsigned int ax;

 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 		goto badframe;
 	if (__get_user(set.sig[0], &frame->sc.oldmask)
 	    || (_COMPAT_NSIG_WORDS > 1
 		&& __copy_from_user((((char *) &set.sig) + 4),
 				    &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 (ia32_restore_sigcontext(regs, &frame->sc, &ax))
 		goto badframe;
 	return ax;

 badframe:
 	signal_fault(regs, frame, "32bit sigreturn");
 	return 0;
 }

 asmlinkage long sys32_rt_sigreturn(struct pt_regs *regs)
 {
 	struct rt_sigframe_ia32 __user *frame;
 	sigset_t set;
 	unsigned int ax;
 	struct pt_regs tregs;

 	frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);

 	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 (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
 		goto badframe;

 	tregs = *regs;
 	if (sys32_sigaltstack(&frame->uc.uc_stack, NULL, &tregs) == -EFAULT)
 		goto badframe;

 	return ax;

 badframe:
 	signal_fault(regs, frame, "32bit rt sigreturn");
 	return 0;
 }

 /*
  * Set up a signal frame.
  */

 static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc,
 				 void __user *fpstate,
 				 struct pt_regs *regs, unsigned int mask)
 {
 	int err = 0;

 	put_user_try {
 		put_user_ex(get_user_seg(gs), (unsigned int __user *)&sc->gs);
 		put_user_ex(get_user_seg(fs), (unsigned int __user *)&sc->fs);
 		put_user_ex(get_user_seg(ds), (unsigned int __user *)&sc->ds);
 		put_user_ex(get_user_seg(es), (unsigned int __user *)&sc->es);

 		put_user_ex(regs->di, &sc->di);
 		put_user_ex(regs->si, &sc->si);
 		put_user_ex(regs->bp, &sc->bp);
 		put_user_ex(regs->sp, &sc->sp);
 		put_user_ex(regs->bx, &sc->bx);
 		put_user_ex(regs->dx, &sc->dx);
 		put_user_ex(regs->cx, &sc->cx);
 		put_user_ex(regs->ax, &sc->ax);
 		put_user_ex(current->thread.trap_no, &sc->trapno);
 		put_user_ex(current->thread.error_code, &sc->err);
 		put_user_ex(regs->ip, &sc->ip);
 		put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
 		put_user_ex(regs->flags, &sc->flags);
 		put_user_ex(regs->sp, &sc->sp_at_signal);
 		put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);

 		put_user_ex(ptr_to_compat(fpstate), &sc->fpstate);

 		/* non-iBCS2 extensions.. */
 		put_user_ex(mask, &sc->oldmask);
 		put_user_ex(current->thread.cr2, &sc->cr2);
 	} put_user_catch(err);

 	return err;
 }

 /*
  * Determine which stack to use..
  */
 static 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 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;
 	}

 	/* This is the legacy signal stack switching. */
 	else if ((regs->ss & 0xffff) != __USER32_DS &&
 		!(ka->sa.sa_flags & SA_RESTORER) &&
 		 ka->sa.sa_restorer)
 		sp = (unsigned long) ka->sa.sa_restorer;

 	if (used_math()) {
 		sp = sp - sig_xstate_ia32_size;
 		*fpstate = (struct _fpstate_ia32 *) sp;
 		if (save_i387_xstate_ia32(*fpstate) < 0)
 			return (void __user *) -1L;
 	}

 	sp -= frame_size;
 	/* Align the stack pointer according to the i386 ABI,
 	 * i.e. so that on function entry ((sp + 4) & 15) == 0. */
 	sp = ((sp + 4) & -16ul) - 4;
 	return (void __user *) sp;
 }

 int ia32_setup_frame(int sig, struct k_sigaction *ka,
 		     compat_sigset_t *set, struct pt_regs *regs)
 {
 	struct sigframe_ia32 __user *frame;
 	void __user *restorer;
 	int err = 0;
 	void __user *fpstate = NULL;

 	/* copy_to_user optimizes that into a single 8 byte store */
 	static const struct {
 		u16 poplmovl;
 		u32 val;
 		u16 int80;
 	} __attribute__((packed)) code = {
 		0xb858,		 /* popl %eax ; movl $...,%eax */
 		__NR_ia32_sigreturn,
 		0x80cd,		/* int $0x80 */
 	};

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

 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 		return -EFAULT;

 	if (__put_user(sig, &frame->sig))
 		return -EFAULT;

 	if (ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
 		return -EFAULT;

 	if (_COMPAT_NSIG_WORDS > 1) {
 		if (__copy_to_user(frame->extramask, &set->sig[1],
 				   sizeof(frame->extramask)))
 			return -EFAULT;
 	}

 	if (ka->sa.sa_flags & SA_RESTORER) {
 		restorer = ka->sa.sa_restorer;
 	} else {
 		/* Return stub is in 32bit vsyscall page */
 		if (current->mm->context.vdso)
 			restorer = VDSO32_SYMBOL(current->mm->context.vdso,
 						 sigreturn);
 		else
 			restorer = &frame->retcode;
 	}

 	put_user_try {
 		put_user_ex(ptr_to_compat(restorer), &frame->pretcode);

 		/*
 		 * These are actually not used anymore, but left because some
 		 * gdb versions depend on them as a marker.
 		 */
 		put_user_ex(*((u64 *)&code), (u64 *)frame->retcode);
 	} put_user_catch(err);

 	if (err)
 		return -EFAULT;

 	/* Set up registers for signal handler */
 	regs->sp = (unsigned long) frame;
 	regs->ip = (unsigned long) ka->sa.sa_handler;

 	/* Make -mregparm=3 work */
 	regs->ax = sig;
 	regs->dx = 0;
 	regs->cx = 0;

 	loadsegment(ds, __USER32_DS);
 	loadsegment(es, __USER32_DS);

 	regs->cs = __USER32_CS;
 	regs->ss = __USER32_DS;

 	return 0;
 }

 int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 			compat_sigset_t *set, struct pt_regs *regs)
 {
 	struct rt_sigframe_ia32 __user *frame;
 	void __user *restorer;
 	int err = 0;
 	void __user *fpstate = NULL;

 	/* __copy_to_user optimizes that into a single 8 byte store */
 	static const struct {
 		u8 movl;
 		u32 val;
 		u16 int80;
 		u8  pad;
 	} __attribute__((packed)) code = {
 		0xb8,
 		__NR_ia32_rt_sigreturn,
 		0x80cd,
 		0,
 	};

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

 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 		return -EFAULT;

 	put_user_try {
 		put_user_ex(sig, &frame->sig);
 		put_user_ex(ptr_to_compat(&frame->info), &frame->pinfo);
 		put_user_ex(ptr_to_compat(&frame->uc), &frame->puc);
 		err |= copy_siginfo_to_user32(&frame->info, info);

 		/* Create the ucontext.  */
 		if (cpu_has_xsave)
 			put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
 		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 |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
 					     regs, set->sig[0]);
 		err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));

 		if (ka->sa.sa_flags & SA_RESTORER)
 			restorer = ka->sa.sa_restorer;
 		else
 			restorer = VDSO32_SYMBOL(current->mm->context.vdso,
 						 rt_sigreturn);
 		put_user_ex(ptr_to_compat(restorer), &frame->pretcode);

 		/*
 		 * Not actually used anymore, but left because some gdb
 		 * versions need it.
 		 */
 		put_user_ex(*((u64 *)&code), (u64 *)frame->retcode);
 	} put_user_catch(err);

 	if (err)
 		return -EFAULT;

 	/* Set up registers for signal handler */
 	regs->sp = (unsigned long) frame;
 	regs->ip = (unsigned long) ka->sa.sa_handler;

 	/* Make -mregparm=3 work */
 	regs->ax = sig;
 	regs->dx = (unsigned long) &frame->info;
 	regs->cx = (unsigned long) &frame->uc;

 	loadsegment(ds, __USER32_DS);
 	loadsegment(es, __USER32_DS);

 	regs->cs = __USER32_CS;
 	regs->ss = __USER32_DS;

 	return 0;
 }
	/*
	* linux/arch/x86_64/ia32/ia32_signal.c
	*
	* Copyright (C) 1991, 1992 Linus Torvalds
	*
	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
	* 2000-12-* x86-64 compatibility mode signal handling by Andi Kleen
	*/

	#include <linux/sched.h>
	#include <linux/mm.h>
	#include <linux/smp.h>
	#include <linux/kernel.h>
	#include <linux/signal.h>
	#include <linux/errno.h>
	#include <linux/wait.h>
	#include <linux/ptrace.h>
	#include <linux/unistd.h>
	#include <linux/stddef.h>
	#include <linux/personality.h>
	#include <linux/compat.h>
	#include <linux/binfmts.h>
	#include <asm/ucontext.h>
	#include <asm/uaccess.h>
	#include <asm/i387.h>
	#include <asm/ptrace.h>
	#include <asm/ia32_unistd.h>
	#include <asm/user32.h>
	#include <asm/sigcontext32.h>
	#include <asm/proto.h>
	#include <asm/vdso.h>
	#include <asm/sigframe.h>
	#include <asm/sys_ia32.h>

	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))

	#define FIX_EFLAGS (X86_EFLAGS_AC \| X86_EFLAGS_OF \| \
	X86_EFLAGS_DF \| X86_EFLAGS_TF \| X86_EFLAGS_SF \| \
	X86_EFLAGS_ZF \| X86_EFLAGS_AF \| X86_EFLAGS_PF \| \
	X86_EFLAGS_CF)

	void signal_fault(struct pt_regs regs, void __user frame, char *where);

	int copy_siginfo_to_user32(compat_siginfo_t __user to, siginfo_t from)
	{
	int err = 0;

	if (!access_ok(VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
	return -EFAULT;

	put_user_try {
	/* If you change siginfo_t structure, please make sure that
	this code is fixed accordingly.
	It should never copy any pad contained in the structure
	to avoid security leaks, but must copy the generic
	3 ints plus the relevant union member. */
	put_user_ex(from->si_signo, &to->si_signo);
	put_user_ex(from->si_errno, &to->si_errno);
	put_user_ex((short)from->si_code, &to->si_code);

	if (from->si_code < 0) {
	put_user_ex(from->si_pid, &to->si_pid);
	put_user_ex(from->si_uid, &to->si_uid);
	put_user_ex(ptr_to_compat(from->si_ptr), &to->si_ptr);
	} else {
	/*
	* First 32bits of unions are always present:
	* si_pid === si_band === si_tid === si_addr(LS half)
	*/
	put_user_ex(from->_sifields._pad[0],
	&to->_sifields._pad[0]);
	switch (from->si_code >> 16) {
	case __SI_FAULT >> 16:
	break;
	case __SI_CHLD >> 16:
	put_user_ex(from->si_utime, &to->si_utime);
	put_user_ex(from->si_stime, &to->si_stime);
	put_user_ex(from->si_status, &to->si_status);
	/* FALL THROUGH */
	default:
	case __SI_KILL >> 16:
	put_user_ex(from->si_uid, &to->si_uid);
	break;
	case __SI_POLL >> 16:
	put_user_ex(from->si_fd, &to->si_fd);
	break;
	case __SI_TIMER >> 16:
	put_user_ex(from->si_overrun, &to->si_overrun);
	put_user_ex(ptr_to_compat(from->si_ptr),
	&to->si_ptr);
	break;
	/* This is not generated by the kernel as of now. */
	case __SI_RT >> 16:
	case __SI_MESGQ >> 16:
	put_user_ex(from->si_uid, &to->si_uid);
	put_user_ex(from->si_int, &to->si_int);
	break;
	}
	}
	} put_user_catch(err);

	return err;
	}

	int copy_siginfo_from_user32(siginfo_t to, compat_siginfo_t __user from)
	{
	int err = 0;
	u32 ptr32;

	if (!access_ok(VERIFY_READ, from, sizeof(compat_siginfo_t)))
	return -EFAULT;

	get_user_try {
	get_user_ex(to->si_signo, &from->si_signo);
	get_user_ex(to->si_errno, &from->si_errno);
	get_user_ex(to->si_code, &from->si_code);

	get_user_ex(to->si_pid, &from->si_pid);
	get_user_ex(to->si_uid, &from->si_uid);
	get_user_ex(ptr32, &from->si_ptr);
	to->si_ptr = compat_ptr(ptr32);
	} get_user_catch(err);

	return err;
	}

	asmlinkage long sys32_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 long sys32_sigaltstack(const stack_ia32_t __user *uss_ptr,
	stack_ia32_t __user *uoss_ptr,
	struct pt_regs *regs)
	{
	stack_t uss, uoss;
	int ret, err = 0;
	mm_segment_t seg;

	if (uss_ptr) {
	u32 ptr;

	memset(&uss, 0, sizeof(stack_t));
	if (!access_ok(VERIFY_READ, uss_ptr, sizeof(stack_ia32_t)))
	return -EFAULT;

	get_user_try {
	get_user_ex(ptr, &uss_ptr->ss_sp);
	get_user_ex(uss.ss_flags, &uss_ptr->ss_flags);
	get_user_ex(uss.ss_size, &uss_ptr->ss_size);
	} get_user_catch(err);

	if (err)
	return -EFAULT;
	uss.ss_sp = compat_ptr(ptr);
	}
	seg = get_fs();
	set_fs(KERNEL_DS);
	ret = do_sigaltstack(uss_ptr ? &uss : NULL, &uoss, regs->sp);
	set_fs(seg);
	if (ret >= 0 && uoss_ptr) {
	if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(stack_ia32_t)))
	return -EFAULT;

	put_user_try {
	put_user_ex(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp);
	put_user_ex(uoss.ss_flags, &uoss_ptr->ss_flags);
	put_user_ex(uoss.ss_size, &uoss_ptr->ss_size);
	} put_user_catch(err);

	if (err)
	ret = -EFAULT;
	}
	return ret;
	}

	/*
	* Do a signal return; undo the signal stack.
	*/
	#define loadsegment_gs(v) load_gs_index(v)
	#define loadsegment_fs(v) loadsegment(fs, v)
	#define loadsegment_ds(v) loadsegment(ds, v)
	#define loadsegment_es(v) loadsegment(es, v)

	#define get_user_seg(seg) ({ unsigned int v; savesegment(seg, v); v; })
	#define set_user_seg(seg, v) loadsegment_##seg(v)

	#define COPY(x) { \
	get_user_ex(regs->x, &sc->x); \
	}

	#define GET_SEG(seg) ({ \
	unsigned short tmp; \
	get_user_ex(tmp, &sc->seg); \
	tmp; \
	})

	#define COPY_SEG_CPL3(seg) do { \
	regs->seg = GET_SEG(seg) \| 3; \
	} while (0)

	#define RELOAD_SEG(seg) { \
	unsigned int pre = GET_SEG(seg); \
	unsigned int cur = get_user_seg(seg); \
	pre \|= 3; \
	if (pre != cur) \
	set_user_seg(seg, pre); \
	}

	static int ia32_restore_sigcontext(struct pt_regs *regs,
	struct sigcontext_ia32 __user *sc,
	unsigned int *pax)
	{
	unsigned int tmpflags, err = 0;
	void __user *buf;
	u32 tmp;

	/* Always make any pending restarted system calls return -EINTR */
	current_thread_info()->restart_block.fn = do_no_restart_syscall;

	get_user_try {
	/*
	* Reload fs and gs if they have changed in the signal
	* handler. This does not handle long fs/gs base changes in
	* the handler, but does not clobber them at least in the
	* normal case.
	*/
	RELOAD_SEG(gs);
	RELOAD_SEG(fs);
	RELOAD_SEG(ds);
	RELOAD_SEG(es);

	COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
	COPY(dx); COPY(cx); COPY(ip);
	/* Don't touch extended registers */

	COPY_SEG_CPL3(cs);
	COPY_SEG_CPL3(ss);

	get_user_ex(tmpflags, &sc->flags);
	regs->flags = (regs->flags & ~FIX_EFLAGS) \| (tmpflags & FIX_EFLAGS);
	/* disable syscall checks */
	regs->orig_ax = -1;

	get_user_ex(tmp, &sc->fpstate);
	buf = compat_ptr(tmp);
	err \|= restore_i387_xstate_ia32(buf);

	get_user_ex(*pax, &sc->ax);
	} get_user_catch(err);

	return err;
	}

	asmlinkage long sys32_sigreturn(struct pt_regs *regs)
	{
	struct sigframe_ia32 __user frame = (struct sigframe_ia32 __user )(regs->sp-8);
	sigset_t set;
	unsigned int ax;

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	goto badframe;
	if (__get_user(set.sig[0], &frame->sc.oldmask)
	\|\| (_COMPAT_NSIG_WORDS > 1
	&& __copy_from_user((((char *) &set.sig) + 4),
	&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 (ia32_restore_sigcontext(regs, &frame->sc, &ax))
	goto badframe;
	return ax;

	badframe:
	signal_fault(regs, frame, "32bit sigreturn");
	return 0;
	}

	asmlinkage long sys32_rt_sigreturn(struct pt_regs *regs)
	{
	struct rt_sigframe_ia32 __user *frame;
	sigset_t set;
	unsigned int ax;
	struct pt_regs tregs;

	frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);

	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 (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
	goto badframe;

	tregs = *regs;
	if (sys32_sigaltstack(&frame->uc.uc_stack, NULL, &tregs) == -EFAULT)
	goto badframe;

	return ax;

	badframe:
	signal_fault(regs, frame, "32bit rt sigreturn");
	return 0;
	}

	/*
	* Set up a signal frame.
	*/

	static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc,
	void __user *fpstate,
	struct pt_regs *regs, unsigned int mask)
	{
	int err = 0;

	put_user_try {
	put_user_ex(get_user_seg(gs), (unsigned int __user *)&sc->gs);
	put_user_ex(get_user_seg(fs), (unsigned int __user *)&sc->fs);
	put_user_ex(get_user_seg(ds), (unsigned int __user *)&sc->ds);
	put_user_ex(get_user_seg(es), (unsigned int __user *)&sc->es);

	put_user_ex(regs->di, &sc->di);
	put_user_ex(regs->si, &sc->si);
	put_user_ex(regs->bp, &sc->bp);
	put_user_ex(regs->sp, &sc->sp);
	put_user_ex(regs->bx, &sc->bx);
	put_user_ex(regs->dx, &sc->dx);
	put_user_ex(regs->cx, &sc->cx);
	put_user_ex(regs->ax, &sc->ax);
	put_user_ex(current->thread.trap_no, &sc->trapno);
	put_user_ex(current->thread.error_code, &sc->err);
	put_user_ex(regs->ip, &sc->ip);
	put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
	put_user_ex(regs->flags, &sc->flags);
	put_user_ex(regs->sp, &sc->sp_at_signal);
	put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);

	put_user_ex(ptr_to_compat(fpstate), &sc->fpstate);

	/* non-iBCS2 extensions.. */
	put_user_ex(mask, &sc->oldmask);
	put_user_ex(current->thread.cr2, &sc->cr2);
	} put_user_catch(err);

	return err;
	}

	/*
	* Determine which stack to use..
	*/
	static 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 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;
	}

	/* This is the legacy signal stack switching. */
	else if ((regs->ss & 0xffff) != __USER32_DS &&
	!(ka->sa.sa_flags & SA_RESTORER) &&
	ka->sa.sa_restorer)
	sp = (unsigned long) ka->sa.sa_restorer;

	if (used_math()) {
	sp = sp - sig_xstate_ia32_size;
	fpstate = (struct _fpstate_ia32 ) sp;
	if (save_i387_xstate_ia32(*fpstate) < 0)
	return (void __user *) -1L;
	}

	sp -= frame_size;
	/* Align the stack pointer according to the i386 ABI,
	* i.e. so that on function entry ((sp + 4) & 15) == 0. */
	sp = ((sp + 4) & -16ul) - 4;
	return (void __user *) sp;
	}

	int ia32_setup_frame(int sig, struct k_sigaction *ka,
	compat_sigset_t set, struct pt_regs regs)
	{
	struct sigframe_ia32 __user *frame;
	void __user *restorer;
	int err = 0;
	void __user *fpstate = NULL;

	/* copy_to_user optimizes that into a single 8 byte store */
	static const struct {
	u16 poplmovl;
	u32 val;
	u16 int80;
	} __attribute__((packed)) code = {
	0xb858, /* popl %eax ; movl $...,%eax */
	__NR_ia32_sigreturn,
	0x80cd, /* int $0x80 */
	};

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

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	return -EFAULT;

	if (__put_user(sig, &frame->sig))
	return -EFAULT;

	if (ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
	return -EFAULT;

	if (_COMPAT_NSIG_WORDS > 1) {
	if (__copy_to_user(frame->extramask, &set->sig[1],
	sizeof(frame->extramask)))
	return -EFAULT;
	}

	if (ka->sa.sa_flags & SA_RESTORER) {
	restorer = ka->sa.sa_restorer;
	} else {
	/* Return stub is in 32bit vsyscall page */
	if (current->mm->context.vdso)
	restorer = VDSO32_SYMBOL(current->mm->context.vdso,
	sigreturn);
	else
	restorer = &frame->retcode;
	}

	put_user_try {
	put_user_ex(ptr_to_compat(restorer), &frame->pretcode);

	/*
	* These are actually not used anymore, but left because some
	* gdb versions depend on them as a marker.
	*/
	put_user_ex(((u64 )&code), (u64 *)frame->retcode);
	} put_user_catch(err);

	if (err)
	return -EFAULT;

	/* Set up registers for signal handler */
	regs->sp = (unsigned long) frame;
	regs->ip = (unsigned long) ka->sa.sa_handler;

	/* Make -mregparm=3 work */
	regs->ax = sig;
	regs->dx = 0;
	regs->cx = 0;

	loadsegment(ds, __USER32_DS);
	loadsegment(es, __USER32_DS);

	regs->cs = __USER32_CS;
	regs->ss = __USER32_DS;

	return 0;
	}

	int ia32_setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
	compat_sigset_t set, struct pt_regs regs)
	{
	struct rt_sigframe_ia32 __user *frame;
	void __user *restorer;
	int err = 0;
	void __user *fpstate = NULL;

	/* __copy_to_user optimizes that into a single 8 byte store */
	static const struct {
	u8 movl;
	u32 val;
	u16 int80;
	u8 pad;
	} __attribute__((packed)) code = {
	0xb8,
	__NR_ia32_rt_sigreturn,
	0x80cd,
	0,
	};

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

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	return -EFAULT;

	put_user_try {
	put_user_ex(sig, &frame->sig);
	put_user_ex(ptr_to_compat(&frame->info), &frame->pinfo);
	put_user_ex(ptr_to_compat(&frame->uc), &frame->puc);
	err \|= copy_siginfo_to_user32(&frame->info, info);

	/* Create the ucontext. */
	if (cpu_has_xsave)
	put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
	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 \|= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
	regs, set->sig[0]);
	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));

	if (ka->sa.sa_flags & SA_RESTORER)
	restorer = ka->sa.sa_restorer;
	else
	restorer = VDSO32_SYMBOL(current->mm->context.vdso,
	rt_sigreturn);
	put_user_ex(ptr_to_compat(restorer), &frame->pretcode);

	/*
	* Not actually used anymore, but left because some gdb
	* versions need it.
	*/
	put_user_ex(((u64 )&code), (u64 *)frame->retcode);
	} put_user_catch(err);

	if (err)
	return -EFAULT;

	/* Set up registers for signal handler */
	regs->sp = (unsigned long) frame;
	regs->ip = (unsigned long) ka->sa.sa_handler;

	/* Make -mregparm=3 work */
	regs->ax = sig;
	regs->dx = (unsigned long) &frame->info;
	regs->cx = (unsigned long) &frame->uc;

	loadsegment(ds, __USER32_DS);
	loadsegment(es, __USER32_DS);

	regs->cs = __USER32_CS;
	regs->ss = __USER32_DS;

	return 0;
	}