arch/mips/kernel/signal_n32.c

   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
  50 extern int setup_sigcontext(struct pt_regs *, struct sigcontext __user *);
  51 extern int restore_sigcontext(struct pt_regs *, struct sigcontext __user *);
  52
  53
  54 /* IRIX compatible stack_t  */
  55 typedef struct sigaltstack32 {
  56         s32 ss_sp;
  57         compat_size_t ss_size;
  58         int ss_flags;
  59 } stack32_t;
  60
  61 struct 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
  69 struct 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
  76 extern void sigset_from_compat(sigset_t *set, compat_sigset_t *compat);
  77
  78 asmlinkage 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
  97 asmlinkage 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
 147 badframe:
 148         force_sig(SIGSEGV, current);
 149 }
 150
 151 static 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
 204 give_sigsegv:
 205         force_sigsegv(signr, current);
 206         return -EFAULT;
 207 }
 208
 209 struct 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 };