text: /*
   * Copyright (C) 2003 Broadcom Corporation
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version 2
   * of the License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
   */
  #include <linux/cache.h>
  #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/compat.h>
  #include <linux/bitops.h>
  
  #include <asm/abi.h>
  #include <asm/asm.h>
  #include <asm/cacheflush.h>
  #include <asm/compat-signal.h>
  #include <asm/sim.h>
  #include <asm/uaccess.h>
  #include <asm/ucontext.h>
  #include <asm/fpu.h>
  #include <asm/cpu-features.h>
  #include <asm/war.h>
  #include <asm/vdso.h>
  
  #include "signal-common.h"
  
  /*
   * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
   */
  #define __NR_N32_restart_syscall	6214
  
  extern int setup_sigcontext(struct pt_regs *, struct sigcontext __user *);
  extern int restore_sigcontext(struct pt_regs *, struct sigcontext __user *);
  
  
  /* IRIX compatible stack_t  */
  typedef struct sigaltstack32 {
  	s32 ss_sp;
  	compat_size_t ss_size;
  	int ss_flags;
  } stack32_t;
  
  struct ucontextn32 {
  	u32                 uc_flags;
  	s32                 uc_link;
  	stack32_t           uc_stack;
  	struct sigcontext   uc_mcontext;
  	compat_sigset_t     uc_sigmask;   /* mask last for extensibility */
  };
  
  struct rt_sigframe_n32 {
  	u32 rs_ass[4];			/* argument save space for o32 */
  	u32 rs_pad[2];			/* Was: signal trampoline */
  	struct compat_siginfo rs_info;
  	struct ucontextn32 rs_uc;
  };
  
  extern void sigset_from_compat(sigset_t *set, compat_sigset_t *compat);
  
  asmlinkage int sysn32_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
  {
  	compat_sigset_t __user *unewset;
  	compat_sigset_t uset;
  	size_t sigsetsize;
  	sigset_t newset;
  
  	/* XXX Don't preclude handling different sized sigset_t's.  */
  	sigsetsize = regs.regs[5];
  	if (sigsetsize != sizeof(sigset_t))
  		return -EINVAL;
  
  	unewset = (compat_sigset_t __user *) regs.regs[4];
  	if (copy_from_user(&uset, unewset, sizeof(uset)))
  		return -EFAULT;
  	sigset_from_compat(&newset, &uset);
  	return sigsuspend(&newset);
  }
  
  asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
  {
  	struct rt_sigframe_n32 __user *frame;
  	mm_segment_t old_fs;
  	sigset_t set;
  	stack_t st;
  	s32 sp;
  	int sig;
  
  	frame = (struct rt_sigframe_n32 __user *) regs.regs[29];
  	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
  		goto badframe;
  	if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
  		goto badframe;
  
  	set_current_blocked(&set);
  
  	sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
  	if (sig < 0)
  		goto badframe;
  	else if (sig)
  		force_sig(sig, current);
  
  	/* The ucontext contains a stack32_t, so we must convert!  */
  	if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
  		goto badframe;
  	st.ss_sp = (void __user *)(long) sp;
  	if (__get_user(st.ss_size, &frame->rs_uc.uc_stack.ss_size))
  		goto badframe;
  	if (__get_user(st.ss_flags, &frame->rs_uc.uc_stack.ss_flags))
  		goto badframe;
  
  	/* It is more difficult to avoid calling this function than to
  	   call it and ignore errors.  */
  	old_fs = get_fs();
  	set_fs(KERNEL_DS);
  	do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
  	set_fs(old_fs);
  
  
  	/*
  	 * Don't let your children do this ...
  	 */
  	__asm__ __volatile__(
  		"move\t$29, %0\n\t"
  		"j\tsyscall_exit"
  		:/* no outputs */
  		:"r" (&regs));
  	/* Unreached */
  
  badframe:
  	force_sig(SIGSEGV, current);
  }
  
  static int setup_rt_frame_n32(void *sig_return, struct k_sigaction *ka,
  	struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info)
  {
  	struct rt_sigframe_n32 __user *frame;
  	int err = 0;
  	s32 sp;
  
  	frame = get_sigframe(ka, regs, sizeof(*frame));
  	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
  		goto give_sigsegv;
  
  	/* Create siginfo.  */
  	err |= copy_siginfo_to_user32(&frame->rs_info, info);
  
  	/* Create the ucontext.  */
  	err |= __put_user(0, &frame->rs_uc.uc_flags);
  	err |= __put_user(0, &frame->rs_uc.uc_link);
  	sp = (int) (long) current->sas_ss_sp;
  	err |= __put_user(sp,
  	                  &frame->rs_uc.uc_stack.ss_sp);
  	err |= __put_user(sas_ss_flags(regs->regs[29]),
  	                  &frame->rs_uc.uc_stack.ss_flags);
  	err |= __put_user(current->sas_ss_size,
  	                  &frame->rs_uc.uc_stack.ss_size);
  	err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
  	err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);
  
  	if (err)
  		goto give_sigsegv;
  
  	/*
  	 * Arguments to signal handler:
  	 *
  	 *   a0 = signal number
  	 *   a1 = 0 (should be cause)
  	 *   a2 = pointer to ucontext
  	 *
  	 * $25 and c0_epc point to the signal handler, $29 points to
  	 * the struct rt_sigframe.
  	 */
  	regs->regs[ 4] = signr;
  	regs->regs[ 5] = (unsigned long) &frame->rs_info;
  	regs->regs[ 6] = (unsigned long) &frame->rs_uc;
  	regs->regs[29] = (unsigned long) frame;
  	regs->regs[31] = (unsigned long) sig_return;
  	regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
  
  	DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
  	       current->comm, current->pid,
  	       frame, regs->cp0_epc, regs->regs[31]);
  
  	return 0;
  
  give_sigsegv:
  	force_sigsegv(signr, current);
  	return -EFAULT;
  }
  
  struct mips_abi mips_abi_n32 = {
  	.setup_rt_frame	= setup_rt_frame_n32,
  	.rt_signal_return_offset =
  		offsetof(struct mips_vdso, n32_rt_signal_trampoline),
  	.restart	= __NR_N32_restart_syscall
  };
  