LXR linux/arch/mips/kernel/signal

   1/*
   2 * Copyright (C) 2003 Broadcom Corporation
   3 *
   4 * This program is free software; you can redistribute it and/or
   5 * modify it under the terms of the GNU General Public License
   6 * as published by the Free Software Foundation; either version 2
   7 * of the License, or (at your option) any later version.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write to the Free Software
  16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17 */
  18#include <linux/cache.h>
  19#include <linux/sched.h>
  20#include <linux/mm.h>
  21#include <linux/smp.h>
  22#include <linux/kernel.h>
  23#include <linux/signal.h>
  24#include <linux/errno.h>
  25#include <linux/wait.h>
  26#include <linux/ptrace.h>
  27#include <linux/unistd.h>
  28#include <linux/compat.h>
  29#include <linux/bitops.h>
  30
  31#include <asm/abi.h>
  32#include <asm/asm.h>
  33#include <asm/cacheflush.h>
  34#include <asm/compat-signal.h>
  35#include <asm/sim.h>
  36#include <asm/uaccess.h>
  37#include <asm/ucontext.h>
  38#include <asm/fpu.h>
  39#include <asm/cpu-features.h>
  40#include <asm/war.h>
  41#include <asm/vdso.h>
  42
  43#include "signal-common.h"
  44
  45/*
  46 * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
  47 */
  48#define __NR_N32_restart_syscall        6214
  49
  50extern int setup_sigcontext(struct pt_regs *, struct sigcontext __user *);
  51extern int restore_sigcontext(struct pt_regs *, struct sigcontext __user *);
  52
  53
  54/* IRIX compatible stack_t  */
  55typedef struct sigaltstack32 {
  56        s32 ss_sp;
  57        compat_size_t ss_size;
  58        int ss_flags;
  59} stack32_t;
  60
  61struct ucontextn32 {
  62        u32                 uc_flags;
  63        s32                 uc_link;
  64        stack32_t           uc_stack;
  65        struct sigcontext   uc_mcontext;
  66        compat_sigset_t     uc_sigmask;   /* mask last for extensibility */
  67};
  68
  69struct rt_sigframe_n32 {
  70        u32 rs_ass[4];                  /* argument save space for o32 */
  71        u32 rs_pad[2];                  /* Was: signal trampoline */
  72        struct compat_siginfo rs_info;
  73        struct ucontextn32 rs_uc;
  74};
  75
  76extern void sigset_from_compat(sigset_t *set, compat_sigset_t *compat);
  77
  78asmlinkage int sysn32_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
  79{
  80        compat_sigset_t __user *unewset;
  81        compat_sigset_t uset;
  82        size_t sigsetsize;
  83        sigset_t newset;
  84
  85        /* XXX Don't preclude handling different sized sigset_t's.  */
  86        sigsetsize = regs.regs[5];
  87        if (sigsetsize != sizeof(sigset_t))
  88                return -EINVAL;
  89
  90        unewset = (compat_sigset_t __user *) regs.regs[4];
  91        if (copy_from_user(&uset, unewset, sizeof(uset)))
  92                return -EFAULT;
  93        sigset_from_compat(&newset, &uset);
  94        return sigsuspend(&newset);
  95}
  96
  97asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
  98{
  99        struct rt_sigframe_n32 __user *frame;
 100        mm_segment_t old_fs;
 101        sigset_t set;
 102        stack_t st;
 103        s32 sp;
 104        int sig;
 105
 106        frame = (struct rt_sigframe_n32 __user *) regs.regs[29];
 107        if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 108                goto badframe;
 109        if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
 110                goto badframe;
 111
 112        set_current_blocked(&set);
 113
 114        sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
 115        if (sig < 0)
 116                goto badframe;
 117        else if (sig)
 118                force_sig(sig, current);
 119
 120        /* The ucontext contains a stack32_t, so we must convert!  */
 121        if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
 122                goto badframe;
 123        st.ss_sp = (void __user *)(long) sp;
 124        if (__get_user(st.ss_size, &frame->rs_uc.uc_stack.ss_size))
 125                goto badframe;
 126        if (__get_user(st.ss_flags, &frame->rs_uc.uc_stack.ss_flags))
 127                goto badframe;
 128
 129        /* It is more difficult to avoid calling this function than to
 130           call it and ignore errors.  */
 131        old_fs = get_fs();
 132        set_fs(KERNEL_DS);
 133        do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
 134        set_fs(old_fs);
 135
 136
 137        /*
 138         * Don't let your children do this ...
 139         */
 140        __asm__ __volatile__(
 141                "move\t$29, %0\n\t"
 142                "j\tsyscall_exit"
 143                :/* no outputs */
 144                :"r" (&regs));
 145        /* Unreached */
 146
 147badframe:
 148        force_sig(SIGSEGV, current);
 149}
 150
 151static int setup_rt_frame_n32(void *sig_return, struct k_sigaction *ka,
 152        struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info)
 153{
 154        struct rt_sigframe_n32 __user *frame;
 155        int err = 0;
 156        s32 sp;
 157
 158        frame = get_sigframe(ka, regs, sizeof(*frame));
 159        if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
 160                goto give_sigsegv;
 161
 162        /* Create siginfo.  */
 163        err |= copy_siginfo_to_user32(&frame->rs_info, info);
 164
 165        /* Create the ucontext.  */
 166        err |= __put_user(0, &frame->rs_uc.uc_flags);
 167        err |= __put_user(0, &frame->rs_uc.uc_link);
 168        sp = (int) (long) current->sas_ss_sp;
 169        err |= __put_user(sp,
 170                          &frame->rs_uc.uc_stack.ss_sp);
 171        err |= __put_user(sas_ss_flags(regs->regs[29]),
 172                          &frame->rs_uc.uc_stack.ss_flags);
 173        err |= __put_user(current->sas_ss_size,
 174                          &frame->rs_uc.uc_stack.ss_size);
 175        err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 176        err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);
 177
 178        if (err)
 179                goto give_sigsegv;
 180
 181        /*
 182         * Arguments to signal handler:
 183         *
 184         *   a0 = signal number
 185         *   a1 = 0 (should be cause)
 186         *   a2 = pointer to ucontext
 187         *
 188         * $25 and c0_epc point to the signal handler, $29 points to
 189         * the struct rt_sigframe.
 190         */
 191        regs->regs[ 4] = signr;
 192        regs->regs[ 5] = (unsigned long) &frame->rs_info;
 193        regs->regs[ 6] = (unsigned long) &frame->rs_uc;
 194        regs->regs[29] = (unsigned long) frame;
 195        regs->regs[31] = (unsigned long) sig_return;
 196        regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 197
 198        DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
 199               current->comm, current->pid,
 200               frame, regs->cp0_epc, regs->regs[31]);
 201
 202        return 0;
 203
 204give_sigsegv:
 205        force_sigsegv(signr, current);
 206        return -EFAULT;
 207}
 208
 209struct mips_abi mips_abi_n32 = {
 210        .setup_rt_frame = setup_rt_frame_n32,
 211        .rt_signal_return_offset =
 212                offsetof(struct mips_vdso, n32_rt_signal_trampoline),
 213        .restart        = __NR_N32_restart_syscall
 214};
 215