arch/sparc/kernel/signal_32.c - arm/linux-arm64-legacy - Git at Google

 /*  linux/arch/sparc/kernel/signal.c
  *
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
  *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
  *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)
  */

 #include <linux/sched.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/mm.h>
 #include <linux/tty.h>
 #include <linux/smp.h>
 #include <linux/binfmts.h>	/* do_coredum */
 #include <linux/bitops.h>
 #include <linux/tracehook.h>

 #include <asm/uaccess.h>
 #include <asm/ptrace.h>
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
 #include <asm/cacheflush.h>	/* flush_sig_insns */
 #include <asm/switch_to.h>

 #include "sigutil.h"
 #include "kernel.h"

 extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
 		   void *fpqueue, unsigned long *fpqdepth);
 extern void fpload(unsigned long *fpregs, unsigned long *fsr);

 struct signal_frame {
 	struct sparc_stackf	ss;
 	__siginfo32_t		info;
 	__siginfo_fpu_t __user	*fpu_save;
 	unsigned long		insns[2] __attribute__ ((aligned (8)));
 	unsigned int		extramask[_NSIG_WORDS - 1];
 	unsigned int		extra_size; /* Should be 0 */
 	__siginfo_rwin_t __user	*rwin_save;
 } __attribute__((aligned(8)));

 struct rt_signal_frame {
 	struct sparc_stackf	ss;
 	siginfo_t		info;
 	struct pt_regs		regs;
 	sigset_t		mask;
 	__siginfo_fpu_t __user	*fpu_save;
 	unsigned int		insns[2];
 	stack_t			stack;
 	unsigned int		extra_size; /* Should be 0 */
 	__siginfo_rwin_t __user	*rwin_save;
 } __attribute__((aligned(8)));

 /* Align macros */
 #define SF_ALIGNEDSZ  (((sizeof(struct signal_frame) + 7) & (~7)))
 #define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame) + 7) & (~7)))

 asmlinkage void do_sigreturn(struct pt_regs *regs)
 {
 	struct signal_frame __user *sf;
 	unsigned long up_psr, pc, npc;
 	sigset_t set;
 	__siginfo_fpu_t __user *fpu_save;
 	__siginfo_rwin_t __user *rwin_save;
 	int err;

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

 	synchronize_user_stack();

 	sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];

 	/* 1. Make sure we are not getting garbage from the user */
 	if (!access_ok(VERIFY_READ, sf, sizeof(*sf)))
 		goto segv_and_exit;

 	if (((unsigned long) sf) & 3)
 		goto segv_and_exit;

 	err = __get_user(pc,  &sf->info.si_regs.pc);
 	err |= __get_user(npc, &sf->info.si_regs.npc);

 	if ((pc | npc) & 3)
 		goto segv_and_exit;

 	/* 2. Restore the state */
 	up_psr = regs->psr;
 	err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));

 	/* User can only change condition codes and FPU enabling in %psr. */
 	regs->psr = (up_psr & ~(PSR_ICC | PSR_EF))
 		  | (regs->psr & (PSR_ICC | PSR_EF));

 	/* Prevent syscall restart.  */
 	pt_regs_clear_syscall(regs);

 	err |= __get_user(fpu_save, &sf->fpu_save);
 	if (fpu_save)
 		err |= restore_fpu_state(regs, fpu_save);
 	err |= __get_user(rwin_save, &sf->rwin_save);
 	if (rwin_save)
 		err |= restore_rwin_state(rwin_save);

 	/* This is pretty much atomic, no amount locking would prevent
 	 * the races which exist anyways.
 	 */
 	err |= __get_user(set.sig[0], &sf->info.si_mask);
 	err |= __copy_from_user(&set.sig[1], &sf->extramask,
 			        (_NSIG_WORDS-1) * sizeof(unsigned int));

 	if (err)
 		goto segv_and_exit;

 	set_current_blocked(&set);
 	return;

 segv_and_exit:
 	force_sig(SIGSEGV, current);
 }

 asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
 {
 	struct rt_signal_frame __user *sf;
 	unsigned int psr, pc, npc;
 	__siginfo_fpu_t __user *fpu_save;
 	__siginfo_rwin_t __user *rwin_save;
 	sigset_t set;
 	int err;

 	synchronize_user_stack();
 	sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
 	if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||
 	    (((unsigned long) sf) & 0x03))
 		goto segv;

 	err = __get_user(pc, &sf->regs.pc);
 	err |= __get_user(npc, &sf->regs.npc);
 	err |= ((pc | npc) & 0x03);

 	err |= __get_user(regs->y, &sf->regs.y);
 	err |= __get_user(psr, &sf->regs.psr);

 	err |= __copy_from_user(&regs->u_regs[UREG_G1],
 				&sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));

 	regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC);

 	/* Prevent syscall restart.  */
 	pt_regs_clear_syscall(regs);

 	err |= __get_user(fpu_save, &sf->fpu_save);
 	if (!err && fpu_save)
 		err |= restore_fpu_state(regs, fpu_save);
 	err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
 	err |= restore_altstack(&sf->stack);

 	if (err)
 		goto segv;

 	regs->pc = pc;
 	regs->npc = npc;

 	err |= __get_user(rwin_save, &sf->rwin_save);
 	if (!err && rwin_save) {
 		if (restore_rwin_state(rwin_save))
 			goto segv;
 	}

 	set_current_blocked(&set);
 	return;
 segv:
 	force_sig(SIGSEGV, current);
 }

 /* Checks if the fp is valid */
 static inline int invalid_frame_pointer(void __user *fp, int fplen)
 {
 	if ((((unsigned long) fp) & 7) || !__access_ok((unsigned long)fp, fplen))
 		return 1;

 	return 0;
 }

 static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
 {
 	unsigned long sp = regs->u_regs[UREG_FP];

 	/*
 	 * 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.
 	 */
 	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
 		return (void __user *) -1L;

 	/* This is the X/Open sanctioned signal stack switching.  */
 	sp = sigsp(sp, ksig) - framesize;

 	/* Always align the stack frame.  This handles two cases.  First,
 	 * sigaltstack need not be mindful of platform specific stack
 	 * alignment.  Second, if we took this signal because the stack
 	 * is not aligned properly, we'd like to take the signal cleanly
 	 * and report that.
 	 */
 	sp &= ~15UL;

 	return (void __user *) sp;
 }

 static int setup_frame(struct ksignal *ksig, struct pt_regs *regs,
 		       sigset_t *oldset)
 {
 	struct signal_frame __user *sf;
 	int sigframe_size, err, wsaved;
 	void __user *tail;

 	/* 1. Make sure everything is clean */
 	synchronize_user_stack();

 	wsaved = current_thread_info()->w_saved;

 	sigframe_size = sizeof(*sf);
 	if (used_math())
 		sigframe_size += sizeof(__siginfo_fpu_t);
 	if (wsaved)
 		sigframe_size += sizeof(__siginfo_rwin_t);

 	sf = (struct signal_frame __user *)
 		get_sigframe(ksig, regs, sigframe_size);

 	if (invalid_frame_pointer(sf, sigframe_size)) {
 		do_exit(SIGILL);
 		return -EINVAL;
 	}

 	tail = sf + 1;

 	/* 2. Save the current process state */
 	err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));

 	err |= __put_user(0, &sf->extra_size);

 	if (used_math()) {
 		__siginfo_fpu_t __user *fp = tail;
 		tail += sizeof(*fp);
 		err |= save_fpu_state(regs, fp);
 		err |= __put_user(fp, &sf->fpu_save);
 	} else {
 		err |= __put_user(0, &sf->fpu_save);
 	}
 	if (wsaved) {
 		__siginfo_rwin_t __user *rwp = tail;
 		tail += sizeof(*rwp);
 		err |= save_rwin_state(wsaved, rwp);
 		err |= __put_user(rwp, &sf->rwin_save);
 	} else {
 		err |= __put_user(0, &sf->rwin_save);
 	}

 	err |= __put_user(oldset->sig[0], &sf->info.si_mask);
 	err |= __copy_to_user(sf->extramask, &oldset->sig[1],
 			      (_NSIG_WORDS - 1) * sizeof(unsigned int));
 	if (!wsaved) {
 		err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
 				      sizeof(struct reg_window32));
 	} else {
 		struct reg_window32 *rp;

 		rp = &current_thread_info()->reg_window[wsaved - 1];
 		err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
 	}
 	if (err)
 		return err;

 	/* 3. signal handler back-trampoline and parameters */
 	regs->u_regs[UREG_FP] = (unsigned long) sf;
 	regs->u_regs[UREG_I0] = ksig->sig;
 	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 	regs->u_regs[UREG_I2] = (unsigned long) &sf->info;

 	/* 4. signal handler */
 	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
 	regs->npc = (regs->pc + 4);

 	/* 5. return to kernel instructions */
 	if (ksig->ka.ka_restorer)
 		regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
 	else {
 		regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);

 		/* mov __NR_sigreturn, %g1 */
 		err |= __put_user(0x821020d8, &sf->insns[0]);

 		/* t 0x10 */
 		err |= __put_user(0x91d02010, &sf->insns[1]);
 		if (err)
 			return err;

 		/* Flush instruction space. */
 		flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
 	}
 	return 0;
 }

 static int setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs,
 			  sigset_t *oldset)
 {
 	struct rt_signal_frame __user *sf;
 	int sigframe_size, wsaved;
 	void __user *tail;
 	unsigned int psr;
 	int err;

 	synchronize_user_stack();
 	wsaved = current_thread_info()->w_saved;
 	sigframe_size = sizeof(*sf);
 	if (used_math())
 		sigframe_size += sizeof(__siginfo_fpu_t);
 	if (wsaved)
 		sigframe_size += sizeof(__siginfo_rwin_t);
 	sf = (struct rt_signal_frame __user *)
 		get_sigframe(ksig, regs, sigframe_size);
 	if (invalid_frame_pointer(sf, sigframe_size)) {
 		do_exit(SIGILL);
 		return -EINVAL;
 	}

 	tail = sf + 1;
 	err  = __put_user(regs->pc, &sf->regs.pc);
 	err |= __put_user(regs->npc, &sf->regs.npc);
 	err |= __put_user(regs->y, &sf->regs.y);
 	psr = regs->psr;
 	if (used_math())
 		psr |= PSR_EF;
 	err |= __put_user(psr, &sf->regs.psr);
 	err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
 	err |= __put_user(0, &sf->extra_size);

 	if (psr & PSR_EF) {
 		__siginfo_fpu_t __user *fp = tail;
 		tail += sizeof(*fp);
 		err |= save_fpu_state(regs, fp);
 		err |= __put_user(fp, &sf->fpu_save);
 	} else {
 		err |= __put_user(0, &sf->fpu_save);
 	}
 	if (wsaved) {
 		__siginfo_rwin_t __user *rwp = tail;
 		tail += sizeof(*rwp);
 		err |= save_rwin_state(wsaved, rwp);
 		err |= __put_user(rwp, &sf->rwin_save);
 	} else {
 		err |= __put_user(0, &sf->rwin_save);
 	}
 	err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));

 	/* Setup sigaltstack */
 	err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);

 	if (!wsaved) {
 		err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
 				      sizeof(struct reg_window32));
 	} else {
 		struct reg_window32 *rp;

 		rp = &current_thread_info()->reg_window[wsaved - 1];
 		err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
 	}

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

 	if (err)
 		return err;

 	regs->u_regs[UREG_FP] = (unsigned long) sf;
 	regs->u_regs[UREG_I0] = ksig->sig;
 	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 	regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;

 	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
 	regs->npc = (regs->pc + 4);

 	if (ksig->ka.ka_restorer)
 		regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
 	else {
 		regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);

 		/* mov __NR_sigreturn, %g1 */
 		err |= __put_user(0x821020d8, &sf->insns[0]);

 		/* t 0x10 */
 		err |= __put_user(0x91d02010, &sf->insns[1]);
 		if (err)
 			return err;

 		/* Flush instruction space. */
 		flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
 	}
 	return 0;
 }

 static inline void
 handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 {
 	sigset_t *oldset = sigmask_to_save();
 	int err;

 	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
 		err = setup_rt_frame(ksig, regs, oldset);
 	else
 		err = setup_frame(ksig, regs, oldset);
 	signal_setup_done(err, ksig, 0);
 }

 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
 				   struct sigaction *sa)
 {
 	switch(regs->u_regs[UREG_I0]) {
 	case ERESTART_RESTARTBLOCK:
 	case ERESTARTNOHAND:
 	no_system_call_restart:
 		regs->u_regs[UREG_I0] = EINTR;
 		regs->psr |= PSR_C;
 		break;
 	case ERESTARTSYS:
 		if (!(sa->sa_flags & SA_RESTART))
 			goto no_system_call_restart;
 		/* fallthrough */
 	case ERESTARTNOINTR:
 		regs->u_regs[UREG_I0] = orig_i0;
 		regs->pc -= 4;
 		regs->npc -= 4;
 	}
 }

 /* Note that 'init' is a special process: it doesn't get signals it doesn't
  * want to handle. Thus you cannot kill init even with a SIGKILL even by
  * mistake.
  */
 static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 {
 	struct ksignal ksig;
 	int restart_syscall;
 	bool has_handler;

 	/* It's a lot of work and synchronization to add a new ptrace
 	 * register for GDB to save and restore in order to get
 	 * orig_i0 correct for syscall restarts when debugging.
 	 *
 	 * Although it should be the case that most of the global
 	 * registers are volatile across a system call, glibc already
 	 * depends upon that fact that we preserve them.  So we can't
 	 * just use any global register to save away the orig_i0 value.
 	 *
 	 * In particular %g2, %g3, %g4, and %g5 are all assumed to be
 	 * preserved across a system call trap by various pieces of
 	 * code in glibc.
 	 *
 	 * %g7 is used as the "thread register".   %g6 is not used in
 	 * any fixed manner.  %g6 is used as a scratch register and
 	 * a compiler temporary, but it's value is never used across
 	 * a system call.  Therefore %g6 is usable for orig_i0 storage.
 	 */
 	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C))
 		regs->u_regs[UREG_G6] = orig_i0;

 	has_handler = get_signal(&ksig);

 	/* If the debugger messes with the program counter, it clears
 	 * the software "in syscall" bit, directing us to not perform
 	 * a syscall restart.
 	 */
 	restart_syscall = 0;
 	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) {
 		restart_syscall = 1;
 		orig_i0 = regs->u_regs[UREG_G6];
 	}

 	if (has_handler) {
 		if (restart_syscall)
 			syscall_restart(orig_i0, regs, &ksig.ka.sa);
 		handle_signal(&ksig, regs);
 	} else {
 		if (restart_syscall) {
 			switch (regs->u_regs[UREG_I0]) {
 			case ERESTARTNOHAND:
 	     		case ERESTARTSYS:
 			case ERESTARTNOINTR:
 				/* replay the system call when we are done */
 				regs->u_regs[UREG_I0] = orig_i0;
 				regs->pc -= 4;
 				regs->npc -= 4;
 				pt_regs_clear_syscall(regs);
 			case ERESTART_RESTARTBLOCK:
 				regs->u_regs[UREG_G1] = __NR_restart_syscall;
 				regs->pc -= 4;
 				regs->npc -= 4;
 				pt_regs_clear_syscall(regs);
 			}
 		}
 		restore_saved_sigmask();
 	}
 }

 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,
 		      unsigned long thread_info_flags)
 {
 	if (thread_info_flags & _TIF_SIGPENDING)
 		do_signal(regs, orig_i0);
 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
 	}
 }

 asmlinkage int do_sys_sigstack(struct sigstack __user *ssptr,
                                struct sigstack __user *ossptr,
                                unsigned long sp)
 {
 	int ret = -EFAULT;

 	/* First see if old state is wanted. */
 	if (ossptr) {
 		if (put_user(current->sas_ss_sp + current->sas_ss_size,
 			     &ossptr->the_stack) ||
 		    __put_user(on_sig_stack(sp), &ossptr->cur_status))
 			goto out;
 	}

 	/* Now see if we want to update the new state. */
 	if (ssptr) {
 		char *ss_sp;

 		if (get_user(ss_sp, &ssptr->the_stack))
 			goto out;
 		/* If the current stack was set with sigaltstack, don't
 		   swap stacks while we are on it.  */
 		ret = -EPERM;
 		if (current->sas_ss_sp && on_sig_stack(sp))
 			goto out;

 		/* Since we don't know the extent of the stack, and we don't
 		   track onstack-ness, but rather calculate it, we must
 		   presume a size.  Ho hum this interface is lossy.  */
 		current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
 		current->sas_ss_size = SIGSTKSZ;
 	}
 	ret = 0;
 out:
 	return ret;
 }
	/* linux/arch/sparc/kernel/signal.c
	*
	* Copyright (C) 1991, 1992 Linus Torvalds
	* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
	* Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
	* Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
	*/

	#include <linux/sched.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/mm.h>
	#include <linux/tty.h>
	#include <linux/smp.h>
	#include <linux/binfmts.h> /* do_coredum */
	#include <linux/bitops.h>
	#include <linux/tracehook.h>

	#include <asm/uaccess.h>
	#include <asm/ptrace.h>
	#include <asm/pgalloc.h>
	#include <asm/pgtable.h>
	#include <asm/cacheflush.h> /* flush_sig_insns */
	#include <asm/switch_to.h>

	#include "sigutil.h"
	#include "kernel.h"

	extern void fpsave(unsigned long fpregs, unsigned long fsr,
	void fpqueue, unsigned long fpqdepth);
	extern void fpload(unsigned long fpregs, unsigned long fsr);

	struct signal_frame {
	struct sparc_stackf ss;
	__siginfo32_t info;
	__siginfo_fpu_t __user *fpu_save;
	unsigned long insns[2] __attribute__ ((aligned (8)));
	unsigned int extramask[_NSIG_WORDS - 1];
	unsigned int extra_size; /* Should be 0 */
	__siginfo_rwin_t __user *rwin_save;
	} __attribute__((aligned(8)));

	struct rt_signal_frame {
	struct sparc_stackf ss;
	siginfo_t info;
	struct pt_regs regs;
	sigset_t mask;
	__siginfo_fpu_t __user *fpu_save;
	unsigned int insns[2];
	stack_t stack;
	unsigned int extra_size; /* Should be 0 */
	__siginfo_rwin_t __user *rwin_save;
	} __attribute__((aligned(8)));

	/* Align macros */
	#define SF_ALIGNEDSZ (((sizeof(struct signal_frame) + 7) & (~7)))
	#define RT_ALIGNEDSZ (((sizeof(struct rt_signal_frame) + 7) & (~7)))

	asmlinkage void do_sigreturn(struct pt_regs *regs)
	{
	struct signal_frame __user *sf;
	unsigned long up_psr, pc, npc;
	sigset_t set;
	__siginfo_fpu_t __user *fpu_save;
	__siginfo_rwin_t __user *rwin_save;
	int err;

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

	synchronize_user_stack();

	sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];

	/* 1. Make sure we are not getting garbage from the user */
	if (!access_ok(VERIFY_READ, sf, sizeof(*sf)))
	goto segv_and_exit;

	if (((unsigned long) sf) & 3)
	goto segv_and_exit;

	err = __get_user(pc, &sf->info.si_regs.pc);
	err \|= __get_user(npc, &sf->info.si_regs.npc);

	if ((pc \| npc) & 3)
	goto segv_and_exit;

	/* 2. Restore the state */
	up_psr = regs->psr;
	err \|= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));

	/* User can only change condition codes and FPU enabling in %psr. */
	regs->psr = (up_psr & ~(PSR_ICC \| PSR_EF))
	\| (regs->psr & (PSR_ICC \| PSR_EF));

	/* Prevent syscall restart. */
	pt_regs_clear_syscall(regs);

	err \|= __get_user(fpu_save, &sf->fpu_save);
	if (fpu_save)
	err \|= restore_fpu_state(regs, fpu_save);
	err \|= __get_user(rwin_save, &sf->rwin_save);
	if (rwin_save)
	err \|= restore_rwin_state(rwin_save);

	/* This is pretty much atomic, no amount locking would prevent
	* the races which exist anyways.
	*/
	err \|= __get_user(set.sig[0], &sf->info.si_mask);
	err \|= __copy_from_user(&set.sig[1], &sf->extramask,
	(_NSIG_WORDS-1) * sizeof(unsigned int));

	if (err)
	goto segv_and_exit;

	set_current_blocked(&set);
	return;

	segv_and_exit:
	force_sig(SIGSEGV, current);
	}

	asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
	{
	struct rt_signal_frame __user *sf;
	unsigned int psr, pc, npc;
	__siginfo_fpu_t __user *fpu_save;
	__siginfo_rwin_t __user *rwin_save;
	sigset_t set;
	int err;

	synchronize_user_stack();
	sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
	if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) \|\|
	(((unsigned long) sf) & 0x03))
	goto segv;

	err = __get_user(pc, &sf->regs.pc);
	err \|= __get_user(npc, &sf->regs.npc);
	err \|= ((pc \| npc) & 0x03);

	err \|= __get_user(regs->y, &sf->regs.y);
	err \|= __get_user(psr, &sf->regs.psr);

	err \|= __copy_from_user(&regs->u_regs[UREG_G1],
	&sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));

	regs->psr = (regs->psr & ~PSR_ICC) \| (psr & PSR_ICC);

	/* Prevent syscall restart. */
	pt_regs_clear_syscall(regs);

	err \|= __get_user(fpu_save, &sf->fpu_save);
	if (!err && fpu_save)
	err \|= restore_fpu_state(regs, fpu_save);
	err \|= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
	err \|= restore_altstack(&sf->stack);

	if (err)
	goto segv;

	regs->pc = pc;
	regs->npc = npc;

	err \|= __get_user(rwin_save, &sf->rwin_save);
	if (!err && rwin_save) {
	if (restore_rwin_state(rwin_save))
	goto segv;
	}

	set_current_blocked(&set);
	return;
	segv:
	force_sig(SIGSEGV, current);
	}

	/* Checks if the fp is valid */
	static inline int invalid_frame_pointer(void __user *fp, int fplen)
	{
	if ((((unsigned long) fp) & 7) \|\| !__access_ok((unsigned long)fp, fplen))
	return 1;

	return 0;
	}

	static inline void __user get_sigframe(struct ksignal ksig, struct pt_regs *regs, unsigned long framesize)
	{
	unsigned long sp = regs->u_regs[UREG_FP];

	/*
	* 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.
	*/
	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
	return (void __user *) -1L;

	/* This is the X/Open sanctioned signal stack switching. */
	sp = sigsp(sp, ksig) - framesize;

	/* Always align the stack frame. This handles two cases. First,
	* sigaltstack need not be mindful of platform specific stack
	* alignment. Second, if we took this signal because the stack
	* is not aligned properly, we'd like to take the signal cleanly
	* and report that.
	*/
	sp &= ~15UL;

	return (void __user *) sp;
	}

	static int setup_frame(struct ksignal ksig, struct pt_regs regs,
	sigset_t *oldset)
	{
	struct signal_frame __user *sf;
	int sigframe_size, err, wsaved;
	void __user *tail;

	/* 1. Make sure everything is clean */
	synchronize_user_stack();

	wsaved = current_thread_info()->w_saved;

	sigframe_size = sizeof(*sf);
	if (used_math())
	sigframe_size += sizeof(__siginfo_fpu_t);
	if (wsaved)
	sigframe_size += sizeof(__siginfo_rwin_t);

	sf = (struct signal_frame __user *)
	get_sigframe(ksig, regs, sigframe_size);

	if (invalid_frame_pointer(sf, sigframe_size)) {
	do_exit(SIGILL);
	return -EINVAL;
	}

	tail = sf + 1;

	/* 2. Save the current process state */
	err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));

	err \|= __put_user(0, &sf->extra_size);

	if (used_math()) {
	__siginfo_fpu_t __user *fp = tail;
	tail += sizeof(*fp);
	err \|= save_fpu_state(regs, fp);
	err \|= __put_user(fp, &sf->fpu_save);
	} else {
	err \|= __put_user(0, &sf->fpu_save);
	}
	if (wsaved) {
	__siginfo_rwin_t __user *rwp = tail;
	tail += sizeof(*rwp);
	err \|= save_rwin_state(wsaved, rwp);
	err \|= __put_user(rwp, &sf->rwin_save);
	} else {
	err \|= __put_user(0, &sf->rwin_save);
	}

	err \|= __put_user(oldset->sig[0], &sf->info.si_mask);
	err \|= __copy_to_user(sf->extramask, &oldset->sig[1],
	(_NSIG_WORDS - 1) * sizeof(unsigned int));
	if (!wsaved) {
	err \|= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
	sizeof(struct reg_window32));
	} else {
	struct reg_window32 *rp;

	rp = &current_thread_info()->reg_window[wsaved - 1];
	err \|= __copy_to_user(sf, rp, sizeof(struct reg_window32));
	}
	if (err)
	return err;

	/* 3. signal handler back-trampoline and parameters */
	regs->u_regs[UREG_FP] = (unsigned long) sf;
	regs->u_regs[UREG_I0] = ksig->sig;
	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	regs->u_regs[UREG_I2] = (unsigned long) &sf->info;

	/* 4. signal handler */
	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
	regs->npc = (regs->pc + 4);

	/* 5. return to kernel instructions */
	if (ksig->ka.ka_restorer)
	regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
	else {
	regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);

	/* mov __NR_sigreturn, %g1 */
	err \|= __put_user(0x821020d8, &sf->insns[0]);

	/* t 0x10 */
	err \|= __put_user(0x91d02010, &sf->insns[1]);
	if (err)
	return err;

	/* Flush instruction space. */
	flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
	}
	return 0;
	}

	static int setup_rt_frame(struct ksignal ksig, struct pt_regs regs,
	sigset_t *oldset)
	{
	struct rt_signal_frame __user *sf;
	int sigframe_size, wsaved;
	void __user *tail;
	unsigned int psr;
	int err;

	synchronize_user_stack();
	wsaved = current_thread_info()->w_saved;
	sigframe_size = sizeof(*sf);
	if (used_math())
	sigframe_size += sizeof(__siginfo_fpu_t);
	if (wsaved)
	sigframe_size += sizeof(__siginfo_rwin_t);
	sf = (struct rt_signal_frame __user *)
	get_sigframe(ksig, regs, sigframe_size);
	if (invalid_frame_pointer(sf, sigframe_size)) {
	do_exit(SIGILL);
	return -EINVAL;
	}

	tail = sf + 1;
	err = __put_user(regs->pc, &sf->regs.pc);
	err \|= __put_user(regs->npc, &sf->regs.npc);
	err \|= __put_user(regs->y, &sf->regs.y);
	psr = regs->psr;
	if (used_math())
	psr \|= PSR_EF;
	err \|= __put_user(psr, &sf->regs.psr);
	err \|= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
	err \|= __put_user(0, &sf->extra_size);

	if (psr & PSR_EF) {
	__siginfo_fpu_t __user *fp = tail;
	tail += sizeof(*fp);
	err \|= save_fpu_state(regs, fp);
	err \|= __put_user(fp, &sf->fpu_save);
	} else {
	err \|= __put_user(0, &sf->fpu_save);
	}
	if (wsaved) {
	__siginfo_rwin_t __user *rwp = tail;
	tail += sizeof(*rwp);
	err \|= save_rwin_state(wsaved, rwp);
	err \|= __put_user(rwp, &sf->rwin_save);
	} else {
	err \|= __put_user(0, &sf->rwin_save);
	}
	err \|= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));

	/* Setup sigaltstack */
	err \|= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);

	if (!wsaved) {
	err \|= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
	sizeof(struct reg_window32));
	} else {
	struct reg_window32 *rp;

	rp = &current_thread_info()->reg_window[wsaved - 1];
	err \|= __copy_to_user(sf, rp, sizeof(struct reg_window32));
	}

	err \|= copy_siginfo_to_user(&sf->info, &ksig->info);

	if (err)
	return err;

	regs->u_regs[UREG_FP] = (unsigned long) sf;
	regs->u_regs[UREG_I0] = ksig->sig;
	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;

	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
	regs->npc = (regs->pc + 4);

	if (ksig->ka.ka_restorer)
	regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
	else {
	regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);

	/* mov __NR_sigreturn, %g1 */
	err \|= __put_user(0x821020d8, &sf->insns[0]);

	/* t 0x10 */
	err \|= __put_user(0x91d02010, &sf->insns[1]);
	if (err)
	return err;

	/* Flush instruction space. */
	flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
	}
	return 0;
	}

	static inline void
	handle_signal(struct ksignal ksig, struct pt_regs regs)
	{
	sigset_t *oldset = sigmask_to_save();
	int err;

	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
	err = setup_rt_frame(ksig, regs, oldset);
	else
	err = setup_frame(ksig, regs, oldset);
	signal_setup_done(err, ksig, 0);
	}

	static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
	struct sigaction *sa)
	{
	switch(regs->u_regs[UREG_I0]) {
	case ERESTART_RESTARTBLOCK:
	case ERESTARTNOHAND:
	no_system_call_restart:
	regs->u_regs[UREG_I0] = EINTR;
	regs->psr \|= PSR_C;
	break;
	case ERESTARTSYS:
	if (!(sa->sa_flags & SA_RESTART))
	goto no_system_call_restart;
	/* fallthrough */
	case ERESTARTNOINTR:
	regs->u_regs[UREG_I0] = orig_i0;
	regs->pc -= 4;
	regs->npc -= 4;
	}
	}

	/* Note that 'init' is a special process: it doesn't get signals it doesn't
	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	* mistake.
	*/
	static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
	{
	struct ksignal ksig;
	int restart_syscall;
	bool has_handler;

	/* It's a lot of work and synchronization to add a new ptrace
	* register for GDB to save and restore in order to get
	* orig_i0 correct for syscall restarts when debugging.
	*
	* Although it should be the case that most of the global
	* registers are volatile across a system call, glibc already
	* depends upon that fact that we preserve them. So we can't
	* just use any global register to save away the orig_i0 value.
	*
	* In particular %g2, %g3, %g4, and %g5 are all assumed to be
	* preserved across a system call trap by various pieces of
	* code in glibc.
	*
	* %g7 is used as the "thread register". %g6 is not used in
	* any fixed manner. %g6 is used as a scratch register and
	* a compiler temporary, but it's value is never used across
	* a system call. Therefore %g6 is usable for orig_i0 storage.
	*/
	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C))
	regs->u_regs[UREG_G6] = orig_i0;

	has_handler = get_signal(&ksig);

	/* If the debugger messes with the program counter, it clears
	* the software "in syscall" bit, directing us to not perform
	* a syscall restart.
	*/
	restart_syscall = 0;
	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) {
	restart_syscall = 1;
	orig_i0 = regs->u_regs[UREG_G6];
	}

	if (has_handler) {
	if (restart_syscall)
	syscall_restart(orig_i0, regs, &ksig.ka.sa);
	handle_signal(&ksig, regs);
	} else {
	if (restart_syscall) {
	switch (regs->u_regs[UREG_I0]) {
	case ERESTARTNOHAND:
	case ERESTARTSYS:
	case ERESTARTNOINTR:
	/* replay the system call when we are done */
	regs->u_regs[UREG_I0] = orig_i0;
	regs->pc -= 4;
	regs->npc -= 4;
	pt_regs_clear_syscall(regs);
	case ERESTART_RESTARTBLOCK:
	regs->u_regs[UREG_G1] = __NR_restart_syscall;
	regs->pc -= 4;
	regs->npc -= 4;
	pt_regs_clear_syscall(regs);
	}
	}
	restore_saved_sigmask();
	}
	}

	void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,
	unsigned long thread_info_flags)
	{
	if (thread_info_flags & _TIF_SIGPENDING)
	do_signal(regs, orig_i0);
	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
	clear_thread_flag(TIF_NOTIFY_RESUME);
	tracehook_notify_resume(regs);
	}
	}

	asmlinkage int do_sys_sigstack(struct sigstack __user *ssptr,
	struct sigstack __user *ossptr,
	unsigned long sp)
	{
	int ret = -EFAULT;

	/* First see if old state is wanted. */
	if (ossptr) {
	if (put_user(current->sas_ss_sp + current->sas_ss_size,
	&ossptr->the_stack) \|\|
	__put_user(on_sig_stack(sp), &ossptr->cur_status))
	goto out;
	}

	/* Now see if we want to update the new state. */
	if (ssptr) {
	char *ss_sp;

	if (get_user(ss_sp, &ssptr->the_stack))
	goto out;
	/* If the current stack was set with sigaltstack, don't
	swap stacks while we are on it. */
	ret = -EPERM;
	if (current->sas_ss_sp && on_sig_stack(sp))
	goto out;

	/* Since we don't know the extent of the stack, and we don't
	track onstack-ness, but rather calculate it, we must
	presume a size. Ho hum this interface is lossy. */
	current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
	current->sas_ss_size = SIGSTKSZ;
	}
	ret = 0;
	out:
	return ret;
	}