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signal32.c

/*  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 <asm/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>

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

/* 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_fpu32_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_fpu_t         fpu_state;
};

typedef struct compat_siginfo{
      int si_signo;
      int si_errno;
      int si_code;

      union {
            int _pad[SI_PAD_SIZE32];

            /* kill() */
            struct {
                  compat_pid_t _pid;            /* sender's pid */
                  unsigned int _uid;            /* sender's uid */
            } _kill;

            /* POSIX.1b timers */
            struct {
                  compat_timer_t _tid;                /* timer id */
                  int _overrun;                 /* overrun count */
                  compat_sigval_t _sigval;            /* same as below */
                  int _sys_private;       /* not to be passed to user */
            } _timer;

            /* POSIX.1b signals */
            struct {
                  compat_pid_t _pid;            /* sender's pid */
                  unsigned int _uid;            /* sender's uid */
                  compat_sigval_t _sigval;
            } _rt;

            /* SIGCHLD */
            struct {
                  compat_pid_t _pid;            /* which child */
                  unsigned int _uid;            /* sender's uid */
                  int _status;                  /* exit code */
                  compat_clock_t _utime;
                  compat_clock_t _stime;
            } _sigchld;

            /* SIGILL, SIGFPE, SIGSEGV, SIGBUS, SIGEMT */
            struct {
                  u32 _addr; /* faulting insn/memory ref. */
                  int _trapno;
            } _sigfault;

            /* SIGPOLL */
            struct {
                  int _band;  /* POLL_IN, POLL_OUT, POLL_MSG */
                  int _fd;
            } _sigpoll;
      } _sifields;
}compat_siginfo_t;

struct rt_signal_frame32 {
      struct sparc_stackf32   ss;
      compat_siginfo_t  info;
      struct pt_regs32  regs;
      compat_sigset_t         mask;
      /* __siginfo_fpu32_t * */ u32 fpu_save;
      unsigned int            insns[2];
      stack_t32         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_fpu_t         fpu_state;
};

/* Align macros */
#define SF_ALIGNEDSZ  (((sizeof(struct signal_frame32) + 7) & (~7)))
#define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame32) + 7) & (~7)))

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

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

      /* If you change siginfo_t structure, please be sure
         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.
         This routine must convert siginfo from 64bit to 32bit as well
         at the same time.  */
      err = __put_user(from->si_signo, &to->si_signo);
      err |= __put_user(from->si_errno, &to->si_errno);
      err |= __put_user((short)from->si_code, &to->si_code);
      if (from->si_code < 0)
            err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
      else {
            switch (from->si_code >> 16) {
            case __SI_TIMER >> 16:
                  err |= __put_user(from->si_tid, &to->si_tid);
                  err |= __put_user(from->si_overrun, &to->si_overrun);
                  err |= __put_user(from->si_int, &to->si_int);
                  break;
            case __SI_CHLD >> 16:
                  err |= __put_user(from->si_utime, &to->si_utime);
                  err |= __put_user(from->si_stime, &to->si_stime);
                  err |= __put_user(from->si_status, &to->si_status);
            default:
                  err |= __put_user(from->si_pid, &to->si_pid);
                  err |= __put_user(from->si_uid, &to->si_uid);
                  break;
            case __SI_FAULT >> 16:
                  err |= __put_user(from->si_trapno, &to->si_trapno);
                  err |= __put_user((unsigned long)from->si_addr, &to->si_addr);
                  break;
            case __SI_POLL >> 16:
                  err |= __put_user(from->si_band, &to->si_band);
                  err |= __put_user(from->si_fd, &to->si_fd);
                  break;
            case __SI_RT >> 16: /* This is not generated by the kernel as of now.  */
            case __SI_MESGQ >> 16:
                  err |= __put_user(from->si_pid, &to->si_pid);
                  err |= __put_user(from->si_uid, &to->si_uid);
                  err |= __put_user(from->si_int, &to->si_int);
                  break;
            }
      }
      return err;
}

/* CAUTION: This is just a very minimalist implementation for the
 *          sake of compat_sys_rt_sigqueueinfo()
 */
int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
{
      if (!access_ok(VERIFY_WRITE, from, sizeof(compat_siginfo_t)))
            return -EFAULT;

      if (copy_from_user(to, from, 3*sizeof(int)) ||
          copy_from_user(to->_sifields._pad, from->_sifields._pad,
                     SI_PAD_SIZE))
            return -EFAULT;

      return 0;
}

static int restore_fpu_state32(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
{
      unsigned long *fpregs = current_thread_info()->fpregs;
      unsigned long fprs;
      int err;
      
      err = __get_user(fprs, &fpu->si_fprs);
      fprs_write(0);
      regs->tstate &= ~TSTATE_PEF;
      if (fprs & FPRS_DL)
            err |= copy_from_user(fpregs, &fpu->si_float_regs[0], (sizeof(unsigned int) * 32));
      if (fprs & FPRS_DU)
            err |= copy_from_user(fpregs+16, &fpu->si_float_regs[32], (sizeof(unsigned int) * 32));
      err |= __get_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
      err |= __get_user(current_thread_info()->gsr[0], &fpu->si_gsr);
      current_thread_info()->fpsaved[0] |= fprs;
      return err;
}

void do_sigreturn32(struct pt_regs *regs)
{
      struct signal_frame32 __user *sf;
      unsigned int psr;
      unsigned pc, npc, fpu_save;
      sigset_t set;
      unsigned seta[_COMPAT_NSIG_WORDS];
      int err, i;
      
      /* Always make any pending restarted system calls return -EINTR */
      current_thread_info()->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 (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||
          (((unsigned long) sf) & 3))
            goto segv;

      get_user(pc, &sf->info.si_regs.pc);
      __get_user(npc, &sf->info.si_regs.npc);

      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 (fpu_save)
            err |= restore_fpu_state32(regs, &sf->fpu_state);
      err |= __get_user(seta[0], &sf->info.si_mask);
      err |= copy_from_user(seta+1, &sf->extramask,
                        (_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));
      if (err)
            goto segv;
      switch (_NSIG_WORDS) {
            case 4: set.sig[3] = seta[6] + (((long)seta[7]) << 32);
            case 3: set.sig[2] = seta[4] + (((long)seta[5]) << 32);
            case 2: set.sig[1] = seta[2] + (((long)seta[3]) << 32);
            case 1: set.sig[0] = seta[0] + (((long)seta[1]) << 32);
      }
      sigdelsetmask(&set, ~_BLOCKABLE);
      spin_lock_irq(&current->sighand->siglock);
      current->blocked = set;
      recalc_sigpending();
      spin_unlock_irq(&current->sighand->siglock);
      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, fpu_save, u_ss_sp;
      mm_segment_t old_fs;
      sigset_t set;
      compat_sigset_t seta;
      stack_t st;
      int err, i;
      
      /* Always make any pending restarted system calls return -EINTR */
      current_thread_info()->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 (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||
          (((unsigned long) sf) & 3))
            goto segv;

      get_user(pc, &sf->regs.pc);
      __get_user(npc, &sf->regs.npc);

      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 (fpu_save)
            err |= restore_fpu_state32(regs, &sf->fpu_state);
      err |= copy_from_user(&seta, &sf->mask, sizeof(compat_sigset_t));
      err |= __get_user(u_ss_sp, &sf->stack.ss_sp);
      st.ss_sp = compat_ptr(u_ss_sp);
      err |= __get_user(st.ss_flags, &sf->stack.ss_flags);
      err |= __get_user(st.ss_size, &sf->stack.ss_size);
      if (err)
            goto segv;
            
      /* 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, (unsigned long)sf);
      set_fs(old_fs);
      
      switch (_NSIG_WORDS) {
            case 4: set.sig[3] = seta.sig[6] + (((long)seta.sig[7]) << 32);
            case 3: set.sig[2] = seta.sig[4] + (((long)seta.sig[5]) << 32);
            case 2: set.sig[1] = seta.sig[2] + (((long)seta.sig[3]) << 32);
            case 1: set.sig[0] = seta.sig[0] + (((long)seta.sig[1]) << 32);
      }
      sigdelsetmask(&set, ~_BLOCKABLE);
      spin_lock_irq(&current->sighand->siglock);
      current->blocked = set;
      recalc_sigpending();
      spin_unlock_irq(&current->sighand->siglock);
      return;
segv:
      force_sig(SIGSEGV, current);
}

/* Checks if the fp is valid */
static int invalid_frame_pointer(void __user *fp, int fplen)
{
      if ((((unsigned long) fp) & 7) || ((unsigned long)fp) > 0x100000000ULL - fplen)
            return 1;
      return 0;
}

static void __user *get_sigframe(struct sigaction *sa, 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.  */
      if (sa->sa_flags & SA_ONSTACK) {
            if (sas_ss_flags(sp) == 0)
                  sp = current->sas_ss_sp + current->sas_ss_size;
      }

      /* 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 &= ~7UL;

      return (void __user *)(sp - framesize);
}

static int save_fpu_state32(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
{
      unsigned long *fpregs = current_thread_info()->fpregs;
      unsigned long fprs;
      int err = 0;
      
      fprs = current_thread_info()->fpsaved[0];
      if (fprs & FPRS_DL)
            err |= copy_to_user(&fpu->si_float_regs[0], fpregs,
                            (sizeof(unsigned int) * 32));
      if (fprs & FPRS_DU)
            err |= copy_to_user(&fpu->si_float_regs[32], fpregs+16,
                            (sizeof(unsigned int) * 32));
      err |= __put_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
      err |= __put_user(current_thread_info()->gsr[0], &fpu->si_gsr);
      err |= __put_user(fprs, &fpu->si_fprs);

      return err;
}

static void setup_frame32(struct k_sigaction *ka, struct pt_regs *regs,
                    int signo, sigset_t *oldset)
{
      struct signal_frame32 __user *sf;
      int sigframe_size;
      u32 psr;
      int i, err;
      unsigned int seta[_COMPAT_NSIG_WORDS];

      /* 1. Make sure everything is clean */
      synchronize_user_stack();
      save_and_clear_fpu();
      
      sigframe_size = SF_ALIGNEDSZ;
      if (!(current_thread_info()->fpsaved[0] & FPRS_FEF))
            sigframe_size -= sizeof(__siginfo_fpu_t);

      sf = (struct signal_frame32 __user *)
            get_sigframe(&ka->sa, regs, sigframe_size);
      
      if (invalid_frame_pointer(sf, sigframe_size))
            goto sigill;

      if (get_thread_wsaved() != 0)
            goto sigill;

      /* 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) {
            err |= save_fpu_state32(regs, &sf->fpu_state);
            err |= __put_user((u64)&sf->fpu_state, &sf->fpu_save);
      } else {
            err |= __put_user(0, &sf->fpu_save);
      }

      switch (_NSIG_WORDS) {
      case 4: seta[7] = (oldset->sig[3] >> 32);
              seta[6] = oldset->sig[3];
      case 3: seta[5] = (oldset->sig[2] >> 32);
              seta[4] = oldset->sig[2];
      case 2: seta[3] = (oldset->sig[1] >> 32);
              seta[2] = oldset->sig[1];
      case 1: seta[1] = (oldset->sig[0] >> 32);
              seta[0] = oldset->sig[0];
      }
      err |= __put_user(seta[0], &sf->info.si_mask);
      err |= __copy_to_user(sf->extramask, seta + 1,
                        (_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));

      err |= copy_in_user((u32 __user *)sf,
                      (u32 __user *)(regs->u_regs[UREG_FP]),
                      sizeof(struct reg_window32));
      
      if (err)
            goto sigsegv;

      /* 3. signal handler back-trampoline and parameters */
      regs->u_regs[UREG_FP] = (unsigned long) sf;
      regs->u_regs[UREG_I0] = signo;
      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) 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 (ka->ka_restorer) {
            regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
      } else {
            /* Flush instruction space. */
            unsigned long address = ((unsigned long)&(sf->insns[0]));
            pgd_t *pgdp = pgd_offset(current->mm, address);
            pud_t *pudp = pud_offset(pgdp, address);
            pmd_t *pmdp = pmd_offset(pudp, address);
            pte_t *ptep;
            pte_t pte;

            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)
                  goto sigsegv;

            preempt_disable();
            ptep = pte_offset_map(pmdp, address);
            pte = *ptep;
            if (pte_present(pte)) {
                  unsigned long page = (unsigned long)
                        page_address(pte_page(pte));

                  wmb();
                  __asm__ __volatile__("flush   %0 + %1"
                                   : /* no outputs */
                                   : "r" (page),
                                     "r" (address & (PAGE_SIZE - 1))
                                   : "memory");
            }
            pte_unmap(ptep);
            preempt_enable();
      }
      return;

sigill:
      do_exit(SIGILL);
sigsegv:
      force_sigsegv(signo, current);
}

static void setup_rt_frame32(struct k_sigaction *ka, struct pt_regs *regs,
                       unsigned long signr, sigset_t *oldset,
                       siginfo_t *info)
{
      struct rt_signal_frame32 __user *sf;
      int sigframe_size;
      u32 psr;
      int i, err;
      compat_sigset_t seta;

      /* 1. Make sure everything is clean */
      synchronize_user_stack();
      save_and_clear_fpu();
      
      sigframe_size = RT_ALIGNEDSZ;
      if (!(current_thread_info()->fpsaved[0] & FPRS_FEF))
            sigframe_size -= sizeof(__siginfo_fpu_t);

      sf = (struct rt_signal_frame32 __user *)
            get_sigframe(&ka->sa, regs, sigframe_size);
      
      if (invalid_frame_pointer(sf, sigframe_size))
            goto sigill;

      if (get_thread_wsaved() != 0)
            goto sigill;

      /* 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) {
            err |= save_fpu_state32(regs, &sf->fpu_state);
            err |= __put_user((u64)&sf->fpu_state, &sf->fpu_save);
      } else {
            err |= __put_user(0, &sf->fpu_save);
      }

      /* Update the siginfo structure.  */
      err |= copy_siginfo_to_user32(&sf->info, info);
      
      /* Setup sigaltstack */
      err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
      err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
      err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);

      switch (_NSIG_WORDS) {
      case 4: seta.sig[7] = (oldset->sig[3] >> 32);
            seta.sig[6] = oldset->sig[3];
      case 3: seta.sig[5] = (oldset->sig[2] >> 32);
            seta.sig[4] = oldset->sig[2];
      case 2: seta.sig[3] = (oldset->sig[1] >> 32);
            seta.sig[2] = oldset->sig[1];
      case 1: seta.sig[1] = (oldset->sig[0] >> 32);
            seta.sig[0] = oldset->sig[0];
      }
      err |= __copy_to_user(&sf->mask, &seta, sizeof(compat_sigset_t));

      err |= copy_in_user((u32 __user *)sf,
                      (u32 __user *)(regs->u_regs[UREG_FP]),
                      sizeof(struct reg_window32));
      if (err)
            goto sigsegv;
      
      /* 3. signal handler back-trampoline and parameters */
      regs->u_regs[UREG_FP] = (unsigned long) sf;
      regs->u_regs[UREG_I0] = signr;
      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) 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 (ka->ka_restorer)
            regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
      else {
            /* Flush instruction space. */
            unsigned long address = ((unsigned long)&(sf->insns[0]));
            pgd_t *pgdp = pgd_offset(current->mm, address);
            pud_t *pudp = pud_offset(pgdp, address);
            pmd_t *pmdp = pmd_offset(pudp, address);
            pte_t *ptep;

            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)
                  goto sigsegv;

            preempt_disable();
            ptep = pte_offset_map(pmdp, address);
            if (pte_present(*ptep)) {
                  unsigned long page = (unsigned long)
                        page_address(pte_page(*ptep));

                  wmb();
                  __asm__ __volatile__("flush   %0 + %1"
                                   : /* no outputs */
                                   : "r" (page),
                                     "r" (address & (PAGE_SIZE - 1))
                                   : "memory");
            }
            pte_unmap(ptep);
            preempt_enable();
      }
      return;

sigill:
      do_exit(SIGILL);
sigsegv:
      force_sigsegv(signr, current);
}

static inline void handle_signal32(unsigned long signr, struct k_sigaction *ka,
                           siginfo_t *info,
                           sigset_t *oldset, struct pt_regs *regs)
{
      if (ka->sa.sa_flags & SA_SIGINFO)
            setup_rt_frame32(ka, regs, signr, oldset, info);
      else
            setup_frame32(ka, regs, signr, oldset);

      spin_lock_irq(&current->sighand->siglock);
      sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
      if (!(ka->sa.sa_flags & SA_NOMASK))
            sigaddset(&current->blocked,signr);
      recalc_sigpending();
      spin_unlock_irq(&current->sighand->siglock);
}

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(sigset_t *oldset, struct pt_regs * regs,
             int restart_syscall, unsigned long orig_i0)
{
      struct k_sigaction ka;
      siginfo_t info;
      int signr;
      
      signr = get_signal_to_deliver(&info, &ka, regs, NULL);

      /* If the debugger messes with the program counter, it clears
       * the "in syscall" bit, directing us to not perform a syscall
       * restart.
       */
      if (restart_syscall && !pt_regs_is_syscall(regs))
            restart_syscall = 0;

      if (signr > 0) {
            if (restart_syscall)
                  syscall_restart32(orig_i0, regs, &ka.sa);
            handle_signal32(signr, &ka, &info, oldset, regs);

            /* A signal was successfully delivered; the saved
             * sigmask will have been stored in the signal frame,
             * and will be restored by sigreturn, so we can simply
             * clear the TS_RESTORE_SIGMASK flag.
             */
            current_thread_info()->status &= ~TS_RESTORE_SIGMASK;

            tracehook_signal_handler(signr, &info, &ka, regs, 0);
            return;
      }
      if (restart_syscall &&
          (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
           regs->u_regs[UREG_I0] == ERESTARTSYS ||
           regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
            /* replay the system call when we are done */
            regs->u_regs[UREG_I0] = orig_i0;
            regs->tpc -= 4;
            regs->tnpc -= 4;
      }
      if (restart_syscall &&
          regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
            regs->u_regs[UREG_G1] = __NR_restart_syscall;
            regs->tpc -= 4;
            regs->tnpc -= 4;
      }

      /* If there's no signal to deliver, we just put the saved sigmask
       * back
       */
      if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
            current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
            sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
      }
}

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;
}

asmlinkage long do_sys32_sigaltstack(u32 ussa, u32 uossa, unsigned long sp)
{
      stack_t uss, uoss;
      u32 u_ss_sp = 0;
      int ret;
      mm_segment_t old_fs;
      stack_t32 __user *uss32 = compat_ptr(ussa);
      stack_t32 __user *uoss32 = compat_ptr(uossa);
      
      if (ussa && (get_user(u_ss_sp, &uss32->ss_sp) ||
                __get_user(uss.ss_flags, &uss32->ss_flags) ||
                __get_user(uss.ss_size, &uss32->ss_size)))
            return -EFAULT;
      uss.ss_sp = compat_ptr(u_ss_sp);
      old_fs = get_fs();
      set_fs(KERNEL_DS);
      ret = do_sigaltstack(ussa ? (stack_t __user *) &uss : NULL,
                       uossa ? (stack_t __user *) &uoss : NULL, sp);
      set_fs(old_fs);
      if (!ret && uossa && (put_user(ptr_to_compat(uoss.ss_sp), &uoss32->ss_sp) ||
                __put_user(uoss.ss_flags, &uoss32->ss_flags) ||
                __put_user(uoss.ss_size, &uoss32->ss_size)))
            return -EFAULT;
      return ret;
}

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