text: // SPDX-License-Identifier: GPL-2.0
  /*  arch/sparc64/kernel/signal32.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)
   *  Copyright (C) 1997,1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
   */
  
  #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/binfmts.h>
  #include <linux/compat.h>
  #include <linux/bitops.h>
  #include <linux/tracehook.h>
  
  #include <linux/uaccess.h>
  #include <asm/ptrace.h>
  #include <asm/pgtable.h>
  #include <asm/psrcompat.h>
  #include <asm/fpumacro.h>
  #include <asm/visasm.h>
  #include <asm/compat_signal.h>
  #include <asm/switch_to.h>
  
  #include "sigutil.h"
  #include "kernel.h"
  
  /* This magic should be in g_upper[0] for all upper parts
   * to be valid.
   */
  #define SIGINFO_EXTRA_V8PLUS_MAGIC	0x130e269
  typedef struct {
  	unsigned int g_upper[8];
  	unsigned int o_upper[8];
  	unsigned int asi;
  } siginfo_extra_v8plus_t;
  
  struct signal_frame32 {
  	struct sparc_stackf32	ss;
  	__siginfo32_t		info;
  	/* __siginfo_fpu_t * */ u32 fpu_save;
  	unsigned int		insns[2];
  	unsigned int		extramask[_COMPAT_NSIG_WORDS - 1];
  	unsigned int		extra_size; /* Should be sizeof(siginfo_extra_v8plus_t) */
  	/* Only valid if (info.si_regs.psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS */
  	siginfo_extra_v8plus_t	v8plus;
  	/* __siginfo_rwin_t * */u32 rwin_save;
  } __attribute__((aligned(8)));
  
  struct rt_signal_frame32 {
  	struct sparc_stackf32	ss;
  	compat_siginfo_t	info;
  	struct pt_regs32	regs;
  	compat_sigset_t		mask;
  	/* __siginfo_fpu_t * */ u32 fpu_save;
  	unsigned int		insns[2];
  	compat_stack_t		stack;
  	unsigned int		extra_size; /* Should be sizeof(siginfo_extra_v8plus_t) */
  	/* Only valid if (regs.psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS */
  	siginfo_extra_v8plus_t	v8plus;
  	/* __siginfo_rwin_t * */u32 rwin_save;
  } __attribute__((aligned(8)));
  
  /* Checks if the fp is valid.  We always build signal frames which are
   * 16-byte aligned, therefore we can always enforce that the restore
   * frame has that property as well.
   */
  static bool invalid_frame_pointer(void __user *fp, int fplen)
  {
  	if ((((unsigned long) fp) & 15) ||
  	    ((unsigned long)fp) > 0x100000000ULL - fplen)
  		return true;
  	return false;
  }
  
  void do_sigreturn32(struct pt_regs *regs)
  {
  	struct signal_frame32 __user *sf;
  	compat_uptr_t fpu_save;
  	compat_uptr_t rwin_save;
  	unsigned int psr, ufp;
  	unsigned int pc, npc;
  	sigset_t set;
  	compat_sigset_t seta;
  	int err, i;
  	
  	/* Always make any pending restarted system calls return -EINTR */
  	current->restart_block.fn = do_no_restart_syscall;
  
  	synchronize_user_stack();
  
  	regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
  	sf = (struct signal_frame32 __user *) regs->u_regs[UREG_FP];
  
  	/* 1. Make sure we are not getting garbage from the user */
  	if (invalid_frame_pointer(sf, sizeof(*sf)))
  		goto segv;
  
  	if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP]))
  		goto segv;
  
  	if (ufp & 0x7)
  		goto segv;
  
  	if (__get_user(pc, &sf->info.si_regs.pc) ||
  	    __get_user(npc, &sf->info.si_regs.npc))
  		goto segv;
  
  	if ((pc | npc) & 3)
  		goto segv;
  
  	if (test_thread_flag(TIF_32BIT)) {
  		pc &= 0xffffffff;
  		npc &= 0xffffffff;
  	}
  	regs->tpc = pc;
  	regs->tnpc = npc;
  
  	/* 2. Restore the state */
  	err = __get_user(regs->y, &sf->info.si_regs.y);
  	err |= __get_user(psr, &sf->info.si_regs.psr);
  
  	for (i = UREG_G1; i <= UREG_I7; i++)
  		err |= __get_user(regs->u_regs[i], &sf->info.si_regs.u_regs[i]);
  	if ((psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS) {
  		err |= __get_user(i, &sf->v8plus.g_upper[0]);
  		if (i == SIGINFO_EXTRA_V8PLUS_MAGIC) {
  			unsigned long asi;
  
  			for (i = UREG_G1; i <= UREG_I7; i++)
  				err |= __get_user(((u32 *)regs->u_regs)[2*i], &sf->v8plus.g_upper[i]);
  			err |= __get_user(asi, &sf->v8plus.asi);
  			regs->tstate &= ~TSTATE_ASI;
  			regs->tstate |= ((asi & 0xffUL) << 24UL);
  		}
  	}
  
  	/* User can only change condition codes in %tstate. */
  	regs->tstate &= ~(TSTATE_ICC|TSTATE_XCC);
  	regs->tstate |= psr_to_tstate_icc(psr);
  
  	/* 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, compat_ptr(fpu_save));
  	err |= __get_user(rwin_save, &sf->rwin_save);
  	if (!err && rwin_save) {
  		if (restore_rwin_state(compat_ptr(rwin_save)))
  			goto segv;
  	}
  	err |= __get_user(seta.sig[0], &sf->info.si_mask);
  	err |= copy_from_user(&seta.sig[1], &sf->extramask,
  			      (_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));
  	if (err)
  	    	goto segv;
  
  	set.sig[0] = seta.sig[0] + (((long)seta.sig[1]) << 32);
  	set_current_blocked(&set);
  	return;
  
  segv:
  	force_sig(SIGSEGV, current);
  }
  
  asmlinkage void do_rt_sigreturn32(struct pt_regs *regs)
  {
  	struct rt_signal_frame32 __user *sf;
  	unsigned int psr, pc, npc, ufp;
  	compat_uptr_t fpu_save;
  	compat_uptr_t rwin_save;
  	sigset_t set;
  	int err, i;
  	
  	/* Always make any pending restarted system calls return -EINTR */
  	current->restart_block.fn = do_no_restart_syscall;
  
  	synchronize_user_stack();
  	regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
  	sf = (struct rt_signal_frame32 __user *) regs->u_regs[UREG_FP];
  
  	/* 1. Make sure we are not getting garbage from the user */
  	if (invalid_frame_pointer(sf, sizeof(*sf)))
  		goto segv;
  
  	if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
  		goto segv;
  
  	if (ufp & 0x7)
  		goto segv;
  
  	if (__get_user(pc, &sf->regs.pc) || 
  	    __get_user(npc, &sf->regs.npc))
  		goto segv;
  
  	if ((pc | npc) & 3)
  		goto segv;
  
  	if (test_thread_flag(TIF_32BIT)) {
  		pc &= 0xffffffff;
  		npc &= 0xffffffff;
  	}
  	regs->tpc = pc;
  	regs->tnpc = npc;
  
  	/* 2. Restore the state */
  	err = __get_user(regs->y, &sf->regs.y);
  	err |= __get_user(psr, &sf->regs.psr);
  	
  	for (i = UREG_G1; i <= UREG_I7; i++)
  		err |= __get_user(regs->u_regs[i], &sf->regs.u_regs[i]);
  	if ((psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS) {
  		err |= __get_user(i, &sf->v8plus.g_upper[0]);
  		if (i == SIGINFO_EXTRA_V8PLUS_MAGIC) {
  			unsigned long asi;
  
  			for (i = UREG_G1; i <= UREG_I7; i++)
  				err |= __get_user(((u32 *)regs->u_regs)[2*i], &sf->v8plus.g_upper[i]);
  			err |= __get_user(asi, &sf->v8plus.asi);
  			regs->tstate &= ~TSTATE_ASI;
  			regs->tstate |= ((asi & 0xffUL) << 24UL);
  		}
  	}
  
  	/* User can only change condition codes in %tstate. */
  	regs->tstate &= ~(TSTATE_ICC|TSTATE_XCC);
  	regs->tstate |= psr_to_tstate_icc(psr);
  
  	/* 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, compat_ptr(fpu_save));
  	err |= get_compat_sigset(&set, &sf->mask);
  	err |= compat_restore_altstack(&sf->stack);
  	if (err)
  		goto segv;
  		
  	err |= __get_user(rwin_save, &sf->rwin_save);
  	if (!err && rwin_save) {
  		if (restore_rwin_state(compat_ptr(rwin_save)))
  			goto segv;
  	}
  
  	set_current_blocked(&set);
  	return;
  segv:
  	force_sig(SIGSEGV, current);
  }
  
  static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
  {
  	unsigned long sp;
  	
  	regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
  	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;
  }
  
  /* The I-cache flush instruction only works in the primary ASI, which
   * right now is the nucleus, aka. kernel space.
   *
   * Therefore we have to kick the instructions out using the kernel
   * side linear mapping of the physical address backing the user
   * instructions.
   */
  static void flush_signal_insns(unsigned long address)
  {
  	unsigned long pstate, paddr;
  	pte_t *ptep, pte;
  	pgd_t *pgdp;
  	pud_t *pudp;
  	pmd_t *pmdp;
  
  	/* Commit all stores of the instructions we are about to flush.  */
  	wmb();
  
  	/* Disable cross-call reception.  In this way even a very wide
  	 * munmap() on another cpu can't tear down the page table
  	 * hierarchy from underneath us, since that can't complete
  	 * until the IPI tlb flush returns.
  	 */
  
  	__asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
  	__asm__ __volatile__("wrpr %0, %1, %%pstate"
  				: : "r" (pstate), "i" (PSTATE_IE));
  
  	pgdp = pgd_offset(current->mm, address);
  	if (pgd_none(*pgdp))
  		goto out_irqs_on;
  	pudp = pud_offset(pgdp, address);
  	if (pud_none(*pudp))
  		goto out_irqs_on;
  	pmdp = pmd_offset(pudp, address);
  	if (pmd_none(*pmdp))
  		goto out_irqs_on;
  
  	ptep = pte_offset_map(pmdp, address);
  	pte = *ptep;
  	if (!pte_present(pte))
  		goto out_unmap;
  
  	paddr = (unsigned long) page_address(pte_page(pte));
  
  	__asm__ __volatile__("flush	%0 + %1"
  			     : /* no outputs */
  			     : "r" (paddr),
  			       "r" (address & (PAGE_SIZE - 1))
  			     : "memory");
  
  out_unmap:
  	pte_unmap(ptep);
  out_irqs_on:
  	__asm__ __volatile__("wrpr %0, 0x0, %%pstate" : : "r" (pstate));
  
  }
  
  static int setup_frame32(struct ksignal *ksig, struct pt_regs *regs,
  			 sigset_t *oldset)
  {
  	struct signal_frame32 __user *sf;
  	int i, err, wsaved;
  	void __user *tail;
  	int sigframe_size;
  	u32 psr;
  	compat_sigset_t seta;
  
  	/* 1. Make sure everything is clean */
  	synchronize_user_stack();
  	save_and_clear_fpu();
  	
  	wsaved = get_thread_wsaved();
  
  	sigframe_size = sizeof(*sf);
  	if (current_thread_info()->fpsaved[0] & FPRS_FEF)
  		sigframe_size += sizeof(__siginfo_fpu_t);
  	if (wsaved)
  		sigframe_size += sizeof(__siginfo_rwin_t);
  
  	sf = (struct signal_frame32 __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 */
  	if (test_thread_flag(TIF_32BIT)) {
  		regs->tpc &= 0xffffffff;
  		regs->tnpc &= 0xffffffff;
  	}
  	err  = put_user(regs->tpc, &sf->info.si_regs.pc);
  	err |= __put_user(regs->tnpc, &sf->info.si_regs.npc);
  	err |= __put_user(regs->y, &sf->info.si_regs.y);
  	psr = tstate_to_psr(regs->tstate);
  	if (current_thread_info()->fpsaved[0] & FPRS_FEF)
  		psr |= PSR_EF;
  	err |= __put_user(psr, &sf->info.si_regs.psr);
  	for (i = 0; i < 16; i++)
  		err |= __put_user(regs->u_regs[i], &sf->info.si_regs.u_regs[i]);
  	err |= __put_user(sizeof(siginfo_extra_v8plus_t), &sf->extra_size);
  	err |= __put_user(SIGINFO_EXTRA_V8PLUS_MAGIC, &sf->v8plus.g_upper[0]);
  	for (i = 1; i < 16; i++)
  		err |= __put_user(((u32 *)regs->u_regs)[2*i],
  				  &sf->v8plus.g_upper[i]);
  	err |= __put_user((regs->tstate & TSTATE_ASI) >> 24UL,
  			  &sf->v8plus.asi);
  
  	if (psr & PSR_EF) {
  		__siginfo_fpu_t __user *fp = tail;
  		tail += sizeof(*fp);
  		err |= save_fpu_state(regs, fp);
  		err |= __put_user((u64)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((u64)rwp, &sf->rwin_save);
  		set_thread_wsaved(0);
  	} else {
  		err |= __put_user(0, &sf->rwin_save);
  	}
  
  	/* If these change we need to know - assignments to seta relies on these sizes */
  	BUILD_BUG_ON(_NSIG_WORDS != 1);
  	BUILD_BUG_ON(_COMPAT_NSIG_WORDS != 2);
  	seta.sig[1] = (oldset->sig[0] >> 32);
  	seta.sig[0] = oldset->sig[0];
  
  	err |= __put_user(seta.sig[0], &sf->info.si_mask);
  	err |= __copy_to_user(sf->extramask, &seta.sig[1],
  			      (_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));
  
  	if (!wsaved) {
  		err |= copy_in_user((u32 __user *)sf,
  				    (u32 __user *)(regs->u_regs[UREG_FP]),
  				    sizeof(struct reg_window32));
  	} else {
  		struct reg_window *rp;
  
  		rp = &current_thread_info()->reg_window[wsaved - 1];
  		for (i = 0; i < 8; i++)
  			err |= __put_user(rp->locals[i], &sf->ss.locals[i]);
  		for (i = 0; i < 6; i++)
  			err |= __put_user(rp->ins[i], &sf->ss.ins[i]);
  		err |= __put_user(rp->ins[6], &sf->ss.fp);
  		err |= __put_user(rp->ins[7], &sf->ss.callers_pc);
  	}	
  	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->tpc = (unsigned long) ksig->ka.sa.sa_handler;
  	regs->tnpc = (regs->tpc + 4);
  	if (test_thread_flag(TIF_32BIT)) {
  		regs->tpc &= 0xffffffff;
  		regs->tnpc &= 0xffffffff;
  	}
  
  	/* 5. return to kernel instructions */
  	if (ksig->ka.ka_restorer) {
  		regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
  	} else {
  		unsigned long address = ((unsigned long)&(sf->insns[0]));
  
  		regs->u_regs[UREG_I7] = (unsigned long) (&(sf->insns[0]) - 2);
  	
  		err  = __put_user(0x821020d8, &sf->insns[0]); /*mov __NR_sigreturn, %g1*/
  		err |= __put_user(0x91d02010, &sf->insns[1]); /*t 0x10*/
  		if (err)
  			return err;
  		flush_signal_insns(address);
  	}
  	return 0;
  }
  
  static int setup_rt_frame32(struct ksignal *ksig, struct pt_regs *regs,
  			    sigset_t *oldset)
  {
  	struct rt_signal_frame32 __user *sf;
  	int i, err, wsaved;
  	void __user *tail;
  	int sigframe_size;
  	u32 psr;
  
  	/* 1. Make sure everything is clean */
  	synchronize_user_stack();
  	save_and_clear_fpu();
  	
  	wsaved = get_thread_wsaved();
  
  	sigframe_size = sizeof(*sf);
  	if (current_thread_info()->fpsaved[0] & FPRS_FEF)
  		sigframe_size += sizeof(__siginfo_fpu_t);
  	if (wsaved)
  		sigframe_size += sizeof(__siginfo_rwin_t);
  
  	sf = (struct rt_signal_frame32 __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 */
  	if (test_thread_flag(TIF_32BIT)) {
  		regs->tpc &= 0xffffffff;
  		regs->tnpc &= 0xffffffff;
  	}
  	err  = put_user(regs->tpc, &sf->regs.pc);
  	err |= __put_user(regs->tnpc, &sf->regs.npc);
  	err |= __put_user(regs->y, &sf->regs.y);
  	psr = tstate_to_psr(regs->tstate);
  	if (current_thread_info()->fpsaved[0] & FPRS_FEF)
  		psr |= PSR_EF;
  	err |= __put_user(psr, &sf->regs.psr);
  	for (i = 0; i < 16; i++)
  		err |= __put_user(regs->u_regs[i], &sf->regs.u_regs[i]);
  	err |= __put_user(sizeof(siginfo_extra_v8plus_t), &sf->extra_size);
  	err |= __put_user(SIGINFO_EXTRA_V8PLUS_MAGIC, &sf->v8plus.g_upper[0]);
  	for (i = 1; i < 16; i++)
  		err |= __put_user(((u32 *)regs->u_regs)[2*i],
  				  &sf->v8plus.g_upper[i]);
  	err |= __put_user((regs->tstate & TSTATE_ASI) >> 24UL,
  			  &sf->v8plus.asi);
  
  	if (psr & PSR_EF) {
  		__siginfo_fpu_t __user *fp = tail;
  		tail += sizeof(*fp);
  		err |= save_fpu_state(regs, fp);
  		err |= __put_user((u64)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((u64)rwp, &sf->rwin_save);
  		set_thread_wsaved(0);
  	} else {
  		err |= __put_user(0, &sf->rwin_save);
  	}
  
  	/* Update the siginfo structure.  */
  	err |= copy_siginfo_to_user32(&sf->info, &ksig->info);
  	
  	/* Setup sigaltstack */
  	err |= __compat_save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
  
  	err |= put_compat_sigset(&sf->mask, oldset, sizeof(compat_sigset_t));
  
  	if (!wsaved) {
  		err |= copy_in_user((u32 __user *)sf,
  				    (u32 __user *)(regs->u_regs[UREG_FP]),
  				    sizeof(struct reg_window32));
  	} else {
  		struct reg_window *rp;
  
  		rp = &current_thread_info()->reg_window[wsaved - 1];
  		for (i = 0; i < 8; i++)
  			err |= __put_user(rp->locals[i], &sf->ss.locals[i]);
  		for (i = 0; i < 6; i++)
  			err |= __put_user(rp->ins[i], &sf->ss.ins[i]);
  		err |= __put_user(rp->ins[6], &sf->ss.fp);
  		err |= __put_user(rp->ins[7], &sf->ss.callers_pc);
  	}
  	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->regs;
  
  	/* 4. signal handler */
  	regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
  	regs->tnpc = (regs->tpc + 4);
  	if (test_thread_flag(TIF_32BIT)) {
  		regs->tpc &= 0xffffffff;
  		regs->tnpc &= 0xffffffff;
  	}
  
  	/* 5. return to kernel instructions */
  	if (ksig->ka.ka_restorer)
  		regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
  	else {
  		unsigned long address = ((unsigned long)&(sf->insns[0]));
  
  		regs->u_regs[UREG_I7] = (unsigned long) (&(sf->insns[0]) - 2);
  	
  		/* mov __NR_rt_sigreturn, %g1 */
  		err |= __put_user(0x82102065, &sf->insns[0]);
  
  		/* t 0x10 */
  		err |= __put_user(0x91d02010, &sf->insns[1]);
  		if (err)
  			return err;
  
  		flush_signal_insns(address);
  	}
  	return 0;
  }
  
  static inline void handle_signal32(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_frame32(ksig, regs, oldset);
  	else
  		err = setup_frame32(ksig, regs, oldset);
  
  	signal_setup_done(err, ksig, 0);
  }
  
  static inline void syscall_restart32(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->tstate |= TSTATE_ICARRY;
  		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->tpc -= 4;
  		regs->tnpc -= 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.
   */
  void do_signal32(struct pt_regs * regs)
  {
  	struct ksignal ksig;
  	unsigned long orig_i0 = 0;
  	int restart_syscall = 0;
  	bool has_handler = get_signal(&ksig);
  
  	if (pt_regs_is_syscall(regs) &&
  	    (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
  		restart_syscall = 1;
  		orig_i0 = regs->u_regs[UREG_G6];
  	}
  
  	if (has_handler) {
  		if (restart_syscall)
  			syscall_restart32(orig_i0, regs, &ksig.ka.sa);
  		handle_signal32(&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->tpc -= 4;
  				regs->tnpc -= 4;
  				pt_regs_clear_syscall(regs);
  			case ERESTART_RESTARTBLOCK:
  				regs->u_regs[UREG_G1] = __NR_restart_syscall;
  				regs->tpc -= 4;
  				regs->tnpc -= 4;
  				pt_regs_clear_syscall(regs);
  			}
  		}
  		restore_saved_sigmask();
  	}
  }
  
  struct sigstack32 {
  	u32 the_stack;
  	int cur_status;
  };
  
  asmlinkage int do_sys32_sigstack(u32 u_ssptr, u32 u_ossptr, unsigned long sp)
  {
  	struct sigstack32 __user *ssptr =
  		(struct sigstack32 __user *)((unsigned long)(u_ssptr));
  	struct sigstack32 __user *ossptr =
  		(struct sigstack32 __user *)((unsigned long)(u_ossptr));
  	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) {
  		u32 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;
  }
  